Roger Junges

• Pederssen, Caroline Othilie Dedekam; Pham, Son Lam; Žugec, Paula; Homolak, Jan; Šutej, Ivana & Junges, Roger (2026). The impact of medical and dental education on student antimicrobial resistance literacy in Croatia. JAC-Antimicrobial Resistance (JAC-AMR). 8(4), s. 1–5. doi: 10.1093/jacamr/dlag183. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk; Salvadori, Gabriela & Junges, Roger (2026). Genetic and functional characterization of the natural transformation system in Streptococcus constellatus. Microbiology (Reading). ISSN 1350-0872. 172(6). doi: 10.1099/mic.0.001726. Fulltekst i vitenarkiv Vis sammendrag

  Streptococcus constellatus is an opportunistic pathogen frequently associated with abscess formation in various body sites. While the species has been shown to acquire exogenous DNA through natural transformation, functional analyses of its underlying mechanisms and optimized genetic editing protocols remain limited. Thus, our aim was to characterize the natural transformation system in S. constellatus and investigate environmental factors coordinating its activation. In addition, we sought to develop an optimized protocol for genome editing. Genomic analysis revealed that 73% of analyzed strains possess orthologs for essential competence regulon genes, with 58% harboring both a complete ComCDE-based operon and the putative transformation machinery required for natural competence. While all complete genomes harbored three copies of the master regulator sigX , the accessory regulator comW was seemingly absent. Lacking the peptide exporter comAB , we demonstrated that S. constellatus utilizes the bacteriocin transporter silED for competence-stimulating peptide export. Gene expression assays indicated system activation at peptide concentrations as low as 4 nM, with peak sigX expression obtained over 60 nM. With the goal of optimizing gene editing strategies, we developed a protocol utilizing rich media supplemented with BSA and calcium chloride, significantly increasing transformation frequencies. Furthermore, we observed that environmental stressors can upregulate the system, including hydrogen peroxide and subinhibitory concentrations of the antibiotics erythromycin, chloramphenicol and ampicillin. Given the increasing clinical relevance of the anginosus group, elucidating horizontal gene transfer mechanisms can provide critical insights into the evolutionary process and pathogenic potential of these species.

• Shawrob, K.S.M.; Sagen, A.S.; Lunde, Tracy Munthali; Sribasgaran, Biramitha; Ghafoor, Saba & Al-Haroni, M. [Vis alle 9 forfattere av denne artikkelen] (2026). Mapping Antibiotic Resistance Determinants in Oral Streptococci. Journal of Dental Research. ISSN 0022-0345. doi: 10.1177/00220345261462871. Fulltekst i vitenarkiv Vis sammendrag

  Antibiotic resistance is a global priority in health care. Leveraging thousands of whole-genome sequences, here we reveal the core resistance determinants of oral streptococci, focusing on assessing pattern variability and gene exchange across commensals and pathogens. Genomic information was obtained from the National Center for Biotechnology Information. Determinants of antibiotic resistance were identified using AMRFinderPlus and the Comprehensive Antibiotic Resistance Database. ICEscreen was employed for calling of integrative and conjugative elements. Variability and recombination in penicillin-binding protein sequences were assessed with MMseqs2 and fastGEAR. A total of 2,087 genomes from 15 species were included, representing the mitis, mutans, anginosus, salivarius, and bovis groups. We observed 3,576 hits from 55 unique resistance genes conferring resistance to 11 antibiotic classes. The species with the most resistance determinants per genome against unique antibiotic classes were Streptococcus mitis (2.7), Streptococcus oralis (2.5), Streptococcus parasanguinis (1.9), Streptococcus gallolyticus (1.3), and Streptococcus anginosus (1.2). The 2 latter species also presented the most diverse composition of determinants. Over 1,800 integrative and conjugative elements were predicted across all genomes, with nearly 17% carrying at least 1 antibiotic resistance gene. Penicillin-binding protein variation analyses showed a high diversity in the mitis group. Even though S. mitis and S. oralis composed less than 4% of the genomes included in the analyses, they were recognized as sources of DNA for over a third of recombination events in pbp1a and nearly half for both pbp2b and pbp2x in β-lactam-resistant isolates of Streptococcus pneumoniae . In summary, we show that tetracycline and macrolide resistance were highly abundant and tightly connected to integrative and conjugative elements. Further, recent recombination data in pbp loci show frequent genetic exchange from oral streptococci to β-lactam-resistant S. pneumoniae . Fundamentally, assessing triggers and the dynamics of genetic exchange across species is central to the development of strategies aiming to mitigate the impact of antibiotic resistance.

• Rotta, Isadora dos Santos; Bitencourt, Fernando Valentim; Collares, Fabrício Mezzomo; Junges, Roger; Samuel, Susana Maria Werner & Toassi, Ramona Fernanda Ceriotti [Vis alle 7 forfattere av denne artikkelen] (2025). Monitoring career impact and satisfaction in a graduate program in dentistry. Frontiers in Dental Medicine. 6. doi: 10.3389/fdmed.2025.1566272. Fulltekst i vitenarkiv
• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Salvadori, Gabriela; Gladstone, Rebecca Ashley & Junges, Roger (2025). Large-scale global molecular epidemiology of antibiotic resistance determinants in Streptococcus pneumoniae. Microbial Genomics. 11(7). doi: 10.1099/mgen.0.001444. Fulltekst i vitenarkiv Vis sammendrag

  Streptococcus pneumoniae is a leading pathogen in terms of deaths attributable to or associated with antimicrobial resistance globally. Thus, monitoring antibiotic resistance determinants constitutes a key aspect of surveillance efforts for this microbe. Leveraging publicly available whole-genome sequencing (WGS) data, we aimed to investigate the presence and distribution patterns of antibiotic resistance determinants in S. pneumoniae with a focus on multidrug resistance (MDR) and serotype distribution. Metadata and genomes were obtained from the National Center for Biotechnology Information Pathogen Detection database. Curation and harmonization were performed in R and SPSS. Data on resistance patterns were defined according to AMRFinderPlus, and a combination of prediction tools was employed for in silico serotyping. Analyses involved 75,161 genomes totalling 122,673 gene/allele counts from 14 antibiotic classes. MDR was observed in 16.7% of isolates, with the highest increasing rates in Asia and South America. Within antibiotic classes, an increase in macrolide resistance genes was highlighted, particularly in the proportion of genomes presenting mef(A)/msr(D). Over a third of isolates with serotypes 19F, 23F, 15A, 6B and 19A showed MDR. We further observed the highest significant increases in the presence of resistance in 33F, 22F, 10A and 23A. Serotype 13, not included in any vaccine formulation, presented high MDR rates with a strong increasing trend. The findings of this study highlight variations in resistance determinants globally and across serotypes over time. Collectively, these data underscore the added value of utilizing public WGS data to investigate the effectiveness and repercussions of treatment and vaccination strategies on managing antibiotic resistance.

• Brar, Navdeep Kaur; Dhariwal, Achal; Shekhar, Sudhanshu; Junges, Roger; Hakansson, Anders P. & Petersen, Fernanda Cristina (2024). HAMLET, a human milk protein-lipid complex, modulates amoxicillin induced changes in an ex vivo biofilm model of the oral microbiome. Frontiers in Microbiology. 15. doi: 10.3389/fmicb.2024.1406190. Fulltekst i vitenarkiv Vis sammendrag

  Challenges from infections caused by biofilms and antimicrobial resistance highlight the need for novel antimicrobials that work in conjunction with antibiotics and minimize resistance risk. In this study we investigated the composite effect of HAMLET (human alpha-lactalbumin made lethal to tumor cells), a human milk protein-lipid complex and amoxicillin on microbial ecology using an ex vivo oral biofilm model with pooled saliva samples. HAMLET was chosen due to its multi-targeted antimicrobial mechanism, together with its synergistic effect with antibiotics on single species pathogens, and low risk of resistance development. The combination of HAMLET and low concentrations of amoxicillin significantly reduced biofilm viability, while each of them alone had little or no impact. Using a whole metagenomics approach, we found that the combination promoted a remarkable shift in overall microbial composition compared to the untreated samples. A large proportion of the bacterial species in the combined treatment were Lactobacillus crispatus, a species with probiotic effects, whereas it was only detected in a minor fraction in untreated samples. Although resistome analysis indicated no major shifts in alpha-diversity, the results showed the presence of TEM beta-lactamase genes in low proportions in all treated samples but absence in untreated samples. Our study illustrates HAMLET’s capability to alter the effects of amoxicillin on the oral microbiome and potentially favor the growth of selected probiotic bacteria when in combination. The findings extend previous knowledge on the combined effects of HAMLET and antibiotics against target pathogens to include potential modulatory effects on polymicrobial biofilms of human origin.

• Neto, Nilson Ferreira de Oliveira; Caixeta, Rafael Antônio Velôso; Zerbinati, Rodrigo Melim; Zarpellon, Amanda Caroline; Caetano, Matheus Willian & Pallos, Debora [Vis alle 11 forfattere av denne artikkelen] (2024). The Emergence of Saliva as a Diagnostic and Prognostic Tool for Viral Infections. Viruses. 16(11). doi: 10.3390/v16111759. Fulltekst i vitenarkiv Vis sammendrag

  Saliva has emerged as a promising diagnostic fluid for viral infections, enabling the direct analysis of viral genetic material and the detection of infection markers such as proteins, metabolites, microRNAs, and immunoglobulins. This comprehensive review aimed to explore the use of saliva as a diagnostic tool for viral infections, emphasizing its advantages and limitations. Saliva stands out due to its simplicity and safety in collection, along with the convenience of self-collection without the need for healthcare supervision, while potentially being comparable to urine and blood in terms of effectiveness. Herein, we highlighted the significant potential of saliva in assessing viral loads and diagnosing viral infections, such as herpesviruses, HPV, PyV, TTV, SARS-CoV-2, and MPXV. The detection of viral shedding in saliva underscores its utility in early diagnosis, the monitoring of infection progression, and evaluating treatment responses. The non-invasive nature of saliva collection makes it an appealing alternative to more invasive methods, promoting better patient compliance and facilitating large-scale screening and surveillance. As such, we further highlight current evidence on the use of saliva as a prognostic tool. Although a significant amount of data is already available, further investigations are warranted to more comprehensively assess the added benefit from the utilization of salivary biomarkers in the clinics. Salivary biomarkers show great promise for the early detection and prevention of viral infection complications, potentially improving disease management and control at the population level. Integrating these non-invasive tools into routine clinical practice could enhance personalized healthcare strategies and patient outcomes. Future studies should focus on establishing standardization protocols, validating the accuracy of salivary diagnostics, and expanding clinical research to enhance the diagnostic and monitoring capabilities of salivary biomarkers.

• Brar, Navdeep Kaur; Dhariwal, Achal; Åmdal, Heidi Aarø; Junges, Roger; Salvadori, Gabriela & Baker, J.L. [Vis alle 8 forfattere av denne artikkelen] (2024). Exploring ex vivo biofilm dynamics: consequences of low ampicillin concentrations on the human oral microbiome. npj Biofilms and Microbiomes. 10(1). doi: 10.1038/s41522-024-00507-7. Fulltekst i vitenarkiv Vis sammendrag

  Prolonged exposure to antibiotics at low concentration can promote processes associated with bacterial biofilm formation, virulence and antibiotic resistance. This can be of high relevance in microbial communities like the oral microbiome, where commensals and pathogens share a common habitat and where the total abundance of antibiotic resistance genes surpasses the abundance in the gut. Here, we used an ex vivo model of human oral biofilms to investigate the impact of ampicillin on biofilm viability. The ecological impact on the microbiome and resistome was investigated using shotgun metagenomics. The results showed that low concentrations promoted significant shifts in microbial taxonomic profile and could enhance biofilm viability by up to 1 to 2-log. For the resistome, low concentrations had no significant impact on antibiotic resistance gene (ARG) diversity, while ARG abundance decreased by up to 84%. A positive correlation was observed between reduced microbial diversity and reduced ARG abundance. The WHO priority pathogens Streptococcus pneumoniae and Staphylococcus aureus were identified in some of the samples, but their abundance was not significantly altered by ampicillin. Most of the antibiotic resistance genes that increased in abundance in the ampicillin group were associated with streptococci, including Streptococcus mitis, a well-known potential donor of ARGs to S. pneumoniae. Overall, the results highlight the potential of using the model to further our understanding of ecological and evolutionary forces driving antimicrobial resistance in oral microbiomes.

• Caixeta, Rafael Antônio Velôso; Batista, Alexandre Mendes; Caetano, Matheus Willian; Palmieri, Michelle; Schwab, Gabriela & Zerbinati, Rodrigo Melim [Vis alle 17 forfattere av denne artikkelen] (2024). Investigation of Oral Shedding of Torquetenovirus (TTV) in Moderate-to-Severe COVID-19 Hospitalised Patients. Viruses. 16(6). doi: 10.3390/v16060831. Fulltekst i vitenarkiv Vis sammendrag

  Background. Torquetenovirus (TTV) is a small DNA virus constituting the human virome. High levels of TTV-DNA have been shown to be associated with immunosuppression and inflammatory chronic disorders. Aim. To assess the possible association between the salivary viral load of TTV-DNA in patients hospitalised due to COVID-19 and disease severity. Methods. Saliva samples collected from 176 patients infected with SARS-CoV-2 were used to investigate the presence of SARS-CoV-2 and TTV-DNA by use of real-time RT-PCR. Results. The majority of patients were male with severe COVID-19. Presence of SARS-CoV-2 was observed in the saliva of 64.77% of patients, showing TTV-DNA in 55.68% of them. Patients with impaired clinical conditions (p < 0.001), which evolved to death (p = 0.003), showed a higher prevalence of TTV-DNA. The median viral load in patients with severe condition was 4.99 log10 copies/mL, in which those who were discharged and those evolving to death had values of 3.96 log10 copies/mL and 6.27 log10 copies/mL, respectively. A statistically significant association was found between the distribution of TTV-DNA viral load in saliva samples and severity of COVID-19 (p = 0.004) and disease outcomes (p < 0.001). Conclusions. These results indicate that TTV-DNA in saliva could be a useful biomarker of COVID-19 severity and prognosis.

• Ghafoor, Saba; Salvadori, Gabriela; Kino, Shiho; Nguyen, Vy Thi Nhat; Nguyen, Tam Thi-Thanh & Ishimaru, Miho [Vis alle 13 forfattere av denne artikkelen] (2024). Insights Into Antimicrobial Resistance From Dental Students in the Asia–Pacific Region. International Dental Journal. ISSN 0020-6539. doi: 10.1016/j.identj.2024.09.016. Fulltekst i vitenarkiv Vis sammendrag

  Background Dentists, as prominent prescribers, are key stakeholders in addressing the antimicrobial resistance (AMR) crisis. Dental students’ perceptions about the topic have been underexplored in the Asia–Pacific region, a key location for the development and spread of AMR. Thus, the aim of this study was to evaluate the awareness and confidence to prescribe antimicrobials amongst dental students studying in the region. Methods Students from 15 dental schools in 4 countries were invited to participate in a cross-sectional online survey during 2022–2023. A previously validated and standardised 14-item instrument was utilised. Results In all, 1413 responses were collected from Australia (n = 165), Sri Lanka (n = 112), Japan (n = 173), and Vietnam (n = 963). Of those, 201 were from final-year students (14.2%). On a scale from 1 to 10, awareness on AMR was placed at a mean (SEM) priority of 8.09 (0.05). With regards to target areas to address for mitigation of the AMR crisis, participants placed general public awareness at the top (mean [SEM] 8.53 [0.05]). Final-year students presented a mean (SEM) level of confidence to prescribe antibiotics of 6.01 (0.14) on a scale from 1 to 10, whilst 59.7% and 56.8% indicated feeling pressured to prescribe by patients or when lacking time, respectively. Final-year students participating in research activities assigned a higher priority to AMR compared to their peers not involved in research (mean [SEM] 8.6 [0.19] vs 7.81 [0.16]; P = .01). Conclusions This study highlights a need for increased awareness and confidence to prescribe amongst dental students in the Asia–Pacific region, an understudied population thus far. To mitigate this issue, the implementation (followed by assessment) of local educational and antibiotic stewardship initiatives is warranted.

• Dornelas-Figueira, Louise Morais; Filho, Antonio Pedro Ricomini; Junges, Roger; Åmdal, Heidi Aarø; Cury, Altair Antoninha Del Bel & Petersen, Fernanda Cristina (2023). In Vitro Impact of Fluconazole on Oral Microbial Communities, Bacterial Growth, and Biofilm Formation. Antibiotics. 12(9). doi: 10.3390/antibiotics12091433. Fulltekst i vitenarkiv Vis sammendrag

  Antifungal agents are widely used to specifically eliminate infections by fungal pathogens. However, the specificity of antifungal agents has been challenged by a few studies demonstrating antibacterial inhibitory effects against Mycobacteria and Streptomyces species. Here, we evaluated for the first time the potential effect of fluconazole, the most clinically used antifungal agent, on a human oral microbiota biofilm model. The results showed that biofilm viability on blood and mitis salivarius agar media was increased over time in the presence of fluconazole at clinically relevant concentrations, despite a reduction in biomass. Targeted PCR revealed a higher abundance of Veillonella atypica, Veillonella dispar, and Lactobacillus spp. in the fluconazole-treated samples compared to the control, while Fusobacterium nucleatum was reduced and Streptococcus spp were not significantly affected. Further, we tested the potential impact of fluconazole using single-species models. Our results, using Streptococcus mutans and Streptococcus mitis luciferase reporters, showed that S. mutans planktonic growth was not significantly affected by fluconazole, whereas for S. mitis, planktonic growth, but not biofilm viability, was inhibited at the highest concentration. Fluconazole’s effects on S. mitis biofilm biomass were concentration and time dependent. Exposure for 48 h to the highest concentration of fluconazole was associated with S. mitis biofilms with the most increased biomass. Potential growth inhibitory effects were further tested using four non-streptococcal species. Among these, the planktonic growth of both Escherichia coli and Granulicatella adiacens was inhibited by fluconazole. The data indicate bacterial responses to fluconazole that extend to a broader range of bacterial species than previously anticipated from the literature, with the potential to disturb biofilm communities.

• Junges, Roger; Khan, Rabia; Tovpeko, Yanina; Åmdal, Heidi Aarø; Petersen, Fernanda Cristina & Morrison, Donald A. (2023). Markerless Genome Editing in Competent Streptococci, Oral Biology. Molecular Techniques and Applications. Springer. ISSN 9781071627792. s. 201–216. doi: 10.1007/978-1-0716-2780-8_13. Fulltekst i vitenarkiv
• Dhariwal, Achal; Bråten, Lars Christian Haugli; Sturød, Kjersti; Silva, Gabriela Salvadori Da; Bargheet, Ahmed & Åmdal, Heidi Aarø [Vis alle 11 forfattere av denne artikkelen] (2023). Differential response to prolonged amoxicillin treatment: long-term resilience of the microbiome versus long-lasting perturbations in the gut resistome. Gut microbes. ISSN 1949-0976. 15(1). doi: 10.1080/19490976.2022.2157200. Fulltekst i vitenarkiv Vis sammendrag

  The collateral impact of antibiotics on the microbiome has attained increasing attention. However, the ecological consequences of long-term antibiotic exposure on the gut microbiome, including anti- biotic resistance, are still limited. Here, we investigated long-term exposure effects to amoxicillin on the human gut microbiome and resistome. Fecal samples were collected from 20 patients receiving 3-months of amoxicillin or placebo treatment as part of a Norwegian multicenter clinical trial on chronic low back pain (AIM study). Samples were collected at baseline, last day of treatment, and 9 months after antibiotic cessation. The abundance and diversity of microbial and resistome composi- tion were characterized using whole shotgun and functional metagenomic sequencing data. While the microbiome profiles of placebo subjects were stable over time, discernible changes in diversity and overall microbiome composition were observed after amoxicillin treatment. In particular, health- associated short-chain fatty acid producing species significantly decreased in proportion. However, these changes were short-lived as the microbiome showed overall recovery 9 months post-treatment. On the other hand, exposure to long-term amoxicillin was associated with an increase in total antimicrobial resistance gene load and diversity of antimicrobial resistance genes, with persistent changes even at 9 months post-treatment. Additionally, beta-lactam resistance was the most affected antibiotic class, suggesting a targeted response to amoxicillin, although changes at the gene level varied across individuals. Overall, our results suggest that the impact of prolonged amoxicillin exposure was more explicit and long-lasting in the fecal resistome than in microbiome composition. Such information is relevant for designing rational administration guidelines for antibiotic therapies.

• Rajar, Polona; Dhariwal, Achal; Silva, Gabriela Salvadori Da; Junges, Roger; Åmdal, Heidi Aarø & Berild, Dag [Vis alle 12 forfattere av denne artikkelen] (2022). Microbial DNA extraction of high-host content and low biomass samples: Optimized protocol for nasopharynx metagenomic studies. Frontiers in Microbiology. 13, s. 1–15. doi: 10.3389/fmicb.2022.1038120. Fulltekst i vitenarkiv Vis sammendrag

  Introduction Low microbial biomass and high human DNA content in nasopharyngeal aspirate samples hinder comprehensive characterization of microbiota and resistome. We obtained samples from premature infants, a group with increased risk of developing respiratory disorders and infections, and consequently frequent exposure to antibiotics. Our aim was to devise an optimal protocol for handling nasopharyngeal aspirate samples from premature infants, focusing on host DNA depletion and microbiome and resistome characterization. Methods Three depletion and three DNA extraction protocols were compared, using RT-PCR and whole metagenome sequencing to determine the efficiency of human DNA removal, taxonomic profiling and assignment of antibiotic resistance genes. Protocols were tested using mock communities, as well as pooled and individual patient samples. Results The only extraction protocol to retrieve the expected DNA yield from mock community samples was based on a lytic method to improve Gram positive recovery (MasterPure™). Host DNA content in non-depleted aliquots from pooled patient samples was 99%. Only samples depleted with MolYsis™ showed satisfactory, but varied reduction in host DNA content, in both pooled and individual patient samples, allowing for microbiome and resistome characterisation (host DNA content from 15% to 98%). Other depletion protocols either retrieved too low total DNA yields, preventing further analysis, or failed to reduce host DNA content. By using Mol_MasterPure protocol on aliquots from pooled patient samples, we increased the number of bacterial reads by 7.6 to 1,725.8-fold compared to non-depleted reference samples. PCR results were indicative of achieved microbial enrichment. Individual patient samples processed with Mol_MasterPure protocol varied greatly in total DNA yield, host DNA content (from 40% to 98%), species and antibiotic resistance gene richness. Discussion Despite high human DNA and low microbial biomass content in nasopharynx aspirates of preterm infants, we were able to reduce host DNA content to levels compatible with downstream shotgun metagenomic analysis, including bacterial species identification and coverage of antibiotic resistance genes. Whole metagenomic sequencing of microbes colonizing the nasopharynx may contribute to explaining the possible role of airway microbiota in respiratory conditions and reveal carriage of antibiotic resistance genes.

• Schwab, Gabriela; Palmieri, Michelle; Zerbinati, Rodrigo M.; Sarmento, Dmitry J. S.; Reis, Thais & Ortega, Karem L. [Vis alle 17 forfattere av denne artikkelen] (2022). Lack of direct association between oral mucosal lesions and SARS-CoV- 2 in a cohort of patients hospitalised with COVID-19. Journal of Oral Microbiology. 14(1). doi: 10.1080/20002297.2022.2047491. Fulltekst i vitenarkiv Vis sammendrag

  Background COVID-19 is a disease affecting various human organs and systems, in which the virus seeks to interact with angiotensin-converting enzyme 2 receptors. These receptors are present in the oral cavity, but the direct relationship between such an interaction and possible oral manifestations of COVID-19 is still unclear. Aim The present study evaluated oral manifestations in a cohort of COVID-19 patients during the period of hospitalisation. Methods In total, 154 patients presenting moderate-to-severe forms of COVID-19 had their oral mucosa examined twice a week until the final outcome, either discharge or death. The oral alterations observed in the patients were grouped into Group 1 (pre-existing conditions and opportunistic oral lesions) and Group 2 (oral mucosal changes related to hospitalization). Results Oral lesions found in the patients of Group 1 are not suggestive of SARS-CoV-2 infection as they are mainly caused by opportunistic infections. On the other hand, oral alterations found in the patients of Group 2 were statistically (P < 0.001) related to intubation and longer period of hospitalisation. Conclusion It is unlikely that ulcerative lesions in the oral cavity are a direct manifestation of SARS-CoV-2 or a marker of COVID-19 progression.

• Bajalan, Aya; Bui, Tiina; Salvadori, Gabriela; Marques, Dalton; Schumacher, Alison & Rösing, Cassiano Kuchenbecker [Vis alle 11 forfattere av denne artikkelen] (2022). Awareness regarding antimicrobial resistance and confidence to prescribe antibiotics in dentistry: a cross-continental student survey. Antimicrobial Resistance & Infection Control. 11(1). doi: 10.1186/s13756-022-01192-x. Fulltekst i vitenarkiv Vis sammendrag

  Background The antimicrobial resistance (AMR) crisis is a major global threat and one of its biggest drivers is the overuse of antibiotics in humans. Dentists are responsible for 5–10% antibiotic prescriptions worldwide and recent data suggest that knowledge and prescribing practices need improvement. Methods A cross-sectional web-survey was sent to dental students from six universities in Norway, Canada, and Brazil. Topics addressed covered awareness, confidence to prescribe antibiotics, and education needs. Data were presented descriptively and statistical testing was employed to compare group means when applicable. Results In total, 562 responses were collected across the three countries with a response rate of 28.6%. ‘Antibiotic resistance’ was among the highest priorities (scale 1–10) with an average of 8.86 (SEM ± 0.05), together with ‘Gender inequality’ (8.68 ± 0.07) and ‘Climate change’ (8.68 ± 0.07). Only 28.8% thought that Dentistry was engaged in national/international campaigns promoting awareness on the topic and 8.9% stated to have heard about the ‘One Health’ concept. Final year dental students showed an average confidence to prescribe antibiotics of 7.59 (± 0.14). Most students demonstrated interest in receiving additional education on all topics listed, with the three most pressing being ‘antibiotic prescription for treatment of infections’ (82.9%), ‘drug interactions’ (80.9%), and ‘spread of antibiotic resistance’ (79.6%). A trend was observed between higher awareness regarding the topic and higher confidence to prescribe. Conclusions There is a need to revisit dental education on antibiotic resistance with a global perspective and to create more stewardship initiatives that promote awareness on the topic.

• Dhariwal, Achal; Junges, Roger; Chen, Tsute & Petersen, Fernanda Cristina (2021). ResistoXplorer: a web-based tool for visual, statistical and exploratory data analysis of resistome data. NAR Genomics and Bioinformatics. 3. doi: 10.1093/nargab/lqab018. Fulltekst i vitenarkiv Vis sammendrag

  The study of resistomes using whole metagenomic sequencing enables high-throughput identification of resistance genes in complex microbial communities, such as the human microbiome. Over recent years, sophisticated and diverse pipelines have been established to facilitate raw data processing and annotation. Despite the progress, there are no easy-to-use tools for comprehensive visual, statistical and functional analysis of resistome data. Thus, exploration of the resulting large complex datasets remains a key bottleneck requiring robust computational resources and technical expertise, which creates a significant hurdle for advancements in the field. Here, we introduce ResistoXplorer, a user-friendly tool that integrates recent advancements in statistics and visualization, coupled with extensive functional annotations and phenotype collection, to enable high-throughput analysis of common outputs generated from metagenomic resistome studies. ResistoXplorer contains three modules—the ‘Antimicrobial Resistance Gene Table’ module offers various options for composition profiling, functional profiling and comparative analysis of resistome data; the ‘Integration’ module supports integrative exploratory analysis of resistome and microbiome abundance profiles derived from metagenomic samples; finally, the ‘Antimicrobial Resistance Gene List’ module enables users to intuitively explore the associations between antimicrobial resistance genes and the microbial hosts using network visual analytics to gain biological insights. ResistoXplorer is publicly available at http://www.resistoxplorer.no.

• Justen, Michelli; Silva, Guilherme Vidal; Lamers, Juliana Maciel de Souza; Junges, Roger & Toassi, Ramona Fernanda Ceriotti (2021). Postgraduate education and employment patterns of dental graduates: a twelve-year analysis (2007 to 2019). Revista da ABENO. ISSN 2595-0274. 21(1). doi: 10.30979/revabeno.v21i1.1687. Fulltekst i vitenarkiv Vis sammendrag

  Avaliar a trajetória de graduados em Odontologia é importante para garantir o alinhamento adequado dos currículos odontológicos às necessidades da sociedade. Este estudo observacional transversal descritivo teve como objetivo caracterizar o perfil sociodemográfico-familiar e a trajetória de educação na pós-graduação e de atuação profissional de cirurgiões-dentistas egressos de universidade pública do Sul do Brasil. Foram convidados a participar do estudo todos os egressos que concluíram a graduação em Odontologia nesta universidade, entre 2007 e 2019. A coleta de dados aconteceu pelo autopreenchimento de instrumento semiestruturado online, pré-testado, organizado em três dimensões (perfil sociodemográfico-familiar, educação na pós-graduação e atuação profissional). A análise das questões objetivas foi realizada por estatísticas descritivas e as abertas pela análise temática de conteúdo. Participaram do estudo 245 cirurgiões-dentistas (percentual de resposta: 25,7%). A maioria eram mulheres (68,6%), com 26 a 32 anos (73,9%), solteiros (71,4%), sem filhos (92,7%), naturais (51,4%) e residentes (59,2%) na cidade onde cursaram Odontologia e trabalham (67,5). A renda pessoal mensal foi de 5 a 10 salários mínimos (36,7%). Atuam na Odontologia (97,1%) e estão satisfeitos com a profissão (79,6%). Realizaram ou estão realizando cursos de pós-graduação (94,3%), concluídos em até três anos após a graduação (58%), principalmente especialização (62,8%), nas áreas de Saúde Coletiva, Ortodontia e Implantodontia. Setor privado mostrou-se o maior empregador dos cirurgiões-dentistas (60,8%), entretanto, a atuação no serviço público cresceu entre os egressos de 2010-2019 (2,4% para 20,7%). Estudos de acompanhamento destes egressos são recomendados para avaliação do curso e das demandas/desafios contextuais que caracterizam a profissão de cirurgião-dentista no Brasil.

• Dhariwal, Achal; Junges, Roger; Chen, Tsute & Petersen, Fernanda Cristina (2020). ResistoXplorer: a web-based tool for visual, statistical and exploratory data analysis of resistome data. BioRxiv. ISSN 0362-4331. doi: 10.1101/2020.08.14.250837. Fulltekst i vitenarkiv
• Celeste, Roger K.; Oliveira, Sara C. & Junges, Roger (2019). Threshold-effect of income on periodontitis and interactions with race/ethnicity and education. Revista Brasileira de Epidemiologia. ISSN 1415-790X. 22. doi: 10.1590/1980-549720190001. Fulltekst i vitenarkiv
• Junges, Roger; Sturød, Kjersti; Salvadori, Gabriela; Åmdal, Heidi Aarø; Chen, Tsute & Petersen, Fernanda Cristina (2019). Characterization of a Signaling System in Streptococcus mitis That Mediates Interspecies Communication with Streptococcus pneumoniae. Applied and Environmental Microbiology. ISSN 0099-2240. 85(2). doi: 10.1128/AEM.02297-18. Fulltekst i vitenarkiv
• Junges, Roger; Salvadori, Gabriela; Chen, Tsute; Morrison, Donald A. & Petersen, Fernanda Cristina (2019). Hidden Gems in the Transcriptome Maps of Competent Streptococci. Frontiers in Molecular Biosciences. 5, s. 1–7. doi: 10.3389/fmolb.2018.00116. Fulltekst i vitenarkiv Vis sammendrag

  Natural transformation is regarded as an important mechanism in bacteria that allows for adaptation to different environmental stressors by ensuring genome plasticity. Since the discovery of this phenomenon in Streptococcus pneumoniae, remarkable progress has been made in the understanding of the molecular mechanisms and pathways coordinating this process. Recently, the advent of high-throughput sequencing allows the posing of questions that address the system at a larger scale but also allow for the creation of high-resolution maps of transcription. Thus, while much is already known about genetic competence in streptococci, recent studies continue to reveal intricate novel regulation pathways and components. In this perspective article, we highlight the use of transcriptional profiling and mapping as a valuable resource in the identification and characterization of “hidden gems” pertinent to the natural transformation system. Such strategies have recently been employed in a variety of different species. In S. mutans, for example, genome editing combined with the power of promoter mapping and RNA-Seq allowed for the identification of a link between the ComCDE and the ComRS systems, a ComR positive feedback loop mediated by SigX, and the XrpA peptide, encoded within sigX, which inhibits competence. In S. pneumoniae, a novel member of the competence regulon termed BriC was found to be directly under control of ComE and to promote biofilm formation and nasopharyngeal colonization but not competence. Together these new technologies enable us to discover new links and to revisit old pathways in the compelling study of natural genetic transformation.

• Junges, Roger; Maienschein-Cline, Mark; Morrison, Donald A. & Petersen, Fernanda Cristina (2019). Complete Genome Sequence of Streptococcus pneumoniae Serotype 19F Strain EF3030. Microbiology Resource Announcements (MRA). 8(19), s. 1–3. doi: 10.1128/MRA.00198-19. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger; Morrison, Donald A. & Petersen, Fernanda Cristina (2019). Competence in Streptococcus pneumoniae and Close Commensal Relatives: Mechanisms and Implications. Frontiers in Cellular and Infection Microbiology. 9:94, s. 1–8. doi: 10.3389/fcimb.2019.00094. Fulltekst i vitenarkiv Vis sammendrag

  The mitis group of streptococci comprises species that are common colonizers of the naso-oral-pharyngeal tract of humans. Streptococcus pneumoniae and Streptococcus mitis are close relatives and share ~60–80% of orthologous genes, but still present striking differences in pathogenic potential toward the human host. S. mitis has long been recognized as a reservoir of antibiotic resistance genes for S. pneumoniae, as well as a source for capsule polysaccharide variation, leading to resistance and vaccine escape. Both species share the ability to become naturally competent, and in this context, competence-associated killing mechanisms such as fratricide are thought to play an important role in interspecies gene exchange. Here, we explore the general mechanism of natural genetic transformation in the two species and touch upon the fundamental clinical and evolutionary implications of sharing similar competence, fratricide mechanisms, and a large fraction of their genomic DNA.

• Sturød, Kjersti; Salvadori, Gabriela; Junges, Roger & Petersen, Fernanda Cristina (2018). Antibiotics alter the window of competence for natural transformation in streptococci. Molecular Oral Microbiology (MOM). ISSN 2041-1006. 33(5), s. 378–387. doi: 10.1111/omi.12240. Fulltekst i vitenarkiv
• A., Cowley Lauren; Petersen, Fernanda Cristina; Junges, Roger; Jimenez, M; Morrison, Donald A. & Hanage, WP (2018). Evolution via recombination: Cell-to-cell contact facilitates larger recombination events in Streptococcus pneumoniae. PLoS Genetics. ISSN 1553-7390. 14(6). doi: 10.1371/journal.pgen.1007410. Fulltekst i vitenarkiv Vis sammendrag

  Homologous recombination in the genetic transformation model organism Streptococcus pneumoniae is thought to be important in the adaptation and evolution of this pathogen. While competent pneumococci are able to scavenge DNA added to laboratory cultures, large-scale transfers of multiple kb are rare under these conditions. We used whole genome sequencing (WGS) to map transfers in recombinants arising from contact of competent cells with non-competent ‘target’ cells, using strains with known genomes, distinguished by a total of ~16,000 SNPs. Experiments designed to explore the effect of environment on large scale recombination events used saturating purified donor DNA, short-term cell assemblages on Millipore filters, and mature biofilm mixed cultures. WGS of 22 recombinants for each environment mapped all SNPs that were identical between the recombinant and the donor but not the recipient. The mean recombination event size was found to be significantly larger in cell-to-cell contact cultures (4051 bp in filter assemblage and 3938 bp in biofilm co-culture versus 1815 bp with saturating DNA). Up to 5.8% of the genome was transferred, through 20 recombination events, to a single recipient, with the largest single event incorporating 29,971 bp. We also found that some recombination events are clustered, that these clusters are more likely to occur in cell-to-cell contact environments, and that they cause significantly increased linkage of genes as far apart as 60,000 bp. We conclude that pneumococcal evolution through homologous recombination is more likely to occur on a larger scale in environments that permit cell-to-cell contact.

• Salvadori, Gabriela; Junges, Roger; Åmdal, Heidi Aarø; Chen, T.; Morrison, D.A. & Petersen, Fernanda Cristina (2018). High-resolution profiles of the Streptococcus mitis CSP signaling pathway reveal core and strain-specific regulated genes. BMC Genomics. 19(1). doi: 10.1186/s12864-018-4802-y. Fulltekst i vitenarkiv Vis sammendrag

  Background In streptococci of the mitis group, competence for natural transformation is a transient physiological state triggered by competence stimulating peptides (CSPs). Although low transformation yields and the absence of a widespread functional competence system have been reported for Streptococcus mitis, recent studies revealed that, at least for some strains, high efficiencies can be achieved following optimization protocols. To gain a deeper insight into competence in this species, we used RNA-seq, to map the global CSP response of two transformable strains: the type strain NCTC12261T and SK321. Results All known genes induced by ComE in Streptococcus pneumoniae, including sigX, were upregulated in the two strains. Likewise, all sets of streptococcal SigX core genes involved in extracellular DNA uptake, recombination, and fratricide were upregulated. No significant differences in the set of induced genes were observed when the type strain was grown in rich or semi-defined media. Five upregulated operons unique to S. mitis with a SigX-box in the promoter region were identified, including two specific to SK321, and one specific to NCTC12261T. Two of the strain-specific operons coded for different bacteriocins. Deletion of the unique S. mitis sigX regulated genes had no effect on transformation. Conclusions Overall, comparison of the global transcriptome in response to CSP shows the conservation of the ComE and SigX-core regulons in competent S. mitis isolates, as well as species and strain-specific genes. Although some S. mitis exhibit truncations in key competence genes, this study shows that in transformable strains, competence seems to depend on the same core genes previously identified in S. pneumoniae.

• K., Gajendrareddy Praveen; Junges, Roger; Cygan, G; Zhao, Y; Marucha, Phillip T. & Engeland, Cristopher G. (2017). Increased oxygen exposure alters collagen expression and tissue architecture during ligature-induced periodontitis. Journal of Periodontal Research. ISSN 0022-3484. 52(3), s. 644–649. doi: 10.1111/jre.12408. Fulltekst i vitenarkiv
• Junges, Roger; Salvadori, Gabriela; Shekhar, Sudhanshu; Åmdal, Heidi Aarø; Periselneris, Jimstan & Chen, Tsute [Vis alle 8 forfattere av denne artikkelen] (2017). A quorum-sensing system that regulates Streptococcus pneumoniae biofilm formation and surface polysaccharide production. mSphere. 2(5), s. 1–18. doi: 10.1128/mSphere.00324-17. Fulltekst i vitenarkiv Vis sammendrag

  Despite vaccines, Streptococcus pneumoniae kills more than a million people yearly. Thus, understanding how pneumococci transition from commensals to pathogens is particularly relevant. Quorum sensing regulates collective behaviors and thus represents a potential driver of commensal-to-pathogen transitions. Rgg/small hydrophobic peptide (SHP) quorum-sensing systems are widespread in streptococci, yet they remain largely uncharacterized in S. pneumoniae. Using directional transcriptome sequencing, we show that the S. pneumoniae D39 Rgg0939/SHP system induces the transcription of a single gene cluster including shp and capsule gene homologs. Capsule size measurements determined by fluorescein isothiocyanate-dextran exclusion allowed assignment of the system to the regulation of surface polysaccharide expression. We found that the SHP pheromone induced exopolysaccharide expression in R36A, an unencapsulated derivative of D39. In the encapsulated parent strain, overexpression of the Rgg system resulted in a mutant with increased capsule size. In line with previous studies showing that capsule expression is inversely associated with biofilm formation, we found that biofilm formed on lung epithelial cells was decreased in the overexpression strain and increased in an rgg deletion mutant. Although no significant differences were observed between D39 and the rgg deletion mutant in a mouse model of lung infection, in competitive assays, overexpression reduced fitness. This is the first study to reveal a quorum-sensing system in streptococci that regulates exopolysaccharide synthesis from a site distinct from the original capsule locus.

• Khan, Rabia; Junges, Roger; Åmdal, Heidi Aarø; Chen, Tsute; Morrison, Donald A & Petersen, Fernanda Cristina (2017). A positive feedback loop mediated by Sigma X enhances expression of the streptococcal regulator ComR. Scientific Reports. 7(1). doi: 10.1038/s41598-017-04768-5. Fulltekst i vitenarkiv Vis sammendrag

  Natural transformation is used by bacteria to take up DNA from their surroundings and incorporate it into their genomes. Streptococci do so during a transient period of competence, triggered by pheromones that they produce, secrete and sense under conditions influenced by the environment. In Streptococcus mutans, Streptococcus suis, and species of the bovis, salivarius and pyogenic groups of streptococci, the pheromone XIP is sensed by the intra-cellular regulator ComR, that in turn activates the transcription of comS, encoding the XIP precursor, and of sigX, encoding the only known alternative sigma factor in streptococci. Although induction of comR during competence has been known for more than fifteen years, the mechanism regulating its expression remains unidentified. By a combination of directional RNA-sequencing, optimal competence conditions, stepwise deletions and marker-less genome editing, we found that SigX is the missing link in overproduction of ComR. In the absence of comR induction, both sigX expression and transformation were significantly reduced. Placing comR and comS transcripts under the control of different regulators so as to form two interlocked positive feedback circuits may enable S. mutans to fine-tune the kinetics and magnitude of the competence response according to their need.

• Salvadori, Gabriela; Junges, Roger; Khan, Rabia; Åmdal, Heidi Aarø; Morrison, Donald A. & Petersen, Fernanda Cristina (2017). Natural transformation of oral streptococci by use of synthetic pheromones. Methods in molecular biology. ISSN 1064-3745. s. 219–232. doi: 10.1007/978-1-4939-6685-1_13. Fulltekst i vitenarkiv Vis sammendrag

  The discovery that Streptococcus pneumoniae uses a competence-stimulating peptide (CSP) to induce competence for natural transformation, and that other species of the mitis and the anginosus streptococcal groups use a similar system, has expanded the tools to explore gene function and regulatory pathways in streptococci. Two other classes of pheromones have been discovered since then, comprising the bacteriocin-inducing peptide class found in Streptococcus mutans (also named CSP, although different from the former) and the SigX-inducing peptides (XIP), in the mutans, salivarius, bovis, and pyogenes groups of streptococci. The three classes of peptide pheromones can be ordered from peptide synthesis services at affordable prices, and used in transformation assays to obtain competent cultures consistently at levels usually higher than those achieved during spontaneous competence. In this chapter, we present protocols for natural transformation of oral streptococci that are based on the use of synthetic pheromones, with examples of conditions optimized for transformation of S. mutans and Streptococcus mitis. This is a post-peer-review, pre-copyedit version of an article published in Oral Biology. © Springer Science+Business Media LLC 2017.

• Junges, Roger; Khan, Rabia; Tovpeko, Yanina; Åmdal, Heidi Aarø; Petersen, Fernanda Cristina & Morrison, Donald (2017). Markerless genome editing in competent streptococci. Methods in molecular biology. ISSN 1064-3745. 1537, s. 233–247. doi: 10.1007/978-1-4939-6685-1_14. Fulltekst i vitenarkiv Vis sammendrag

  Selective markers employed in classical mutagenesis methods using natural genetic transformation can affect gene expression, risk phenotypic effects, and accumulate as unwanted genes during successive mutagenesis cycles. In this chapter, we present a protocol for markerless genome editing in Streptococcus mutans and Streptococcus pneumoniae achieved with an efficient method for natural transformation. High yields of transformants are obtained by combining the unimodal state of competence developed after treatment of S. mutans with sigX-inducing peptide pheromone (XIP) in a chemically defined medium (CDM) or of S. pneumoniae with the competence-stimulating peptide (CSP) together with use of a donor amplicon carrying extensive flanking homology. This combination ensures efficient and precise integration of a new allele by the recombination machinery present in competent cells. This is a post-peer-review, pre-copyedit version of an article published in Oral Biology. © Springer Science+Business Media LLC 2017

• Engeland, C. G.; Hugo, F. N.; Hilgert, J. B.; Nascimento, G. G.; Junges, Roger & Lim, H. J. [Vis alle 8 forfattere av denne artikkelen] (2016). Psychological distress and salivary secretory immunity. Brain, Behavior, and Immunity. ISSN 0889-1591. 52, s. 11–17. doi: 10.1016/j.bbi.2015.08.017. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger; Morrison, Donald A. & Petersen, Fernanda Cristina (2016). Overcoming the barrier of low efficiency during Genetic transformation of Streptococcus mitis. Frontiers in Microbiology. 7. doi: 10.3389/fmicb.2016.01009. Fulltekst i vitenarkiv Vis sammendrag

  Objective: Streptococcus mitis is a predominant oral colonizer, but difficulties in genetic manipulation of this species have hampered our understanding of the mechanisms it uses for colonization of oral surfaces. The aim of this study was to reveal optimal conditions for natural genetic transformation in S. mitis and illustrate its application in direct genome editing. Methods: Luciferase reporter assays were used to assess gene expression of the alternative sigma factor (σX) in combination with natural transformation experiments to evaluate the efficiency by which S. mitis activates the competence system and incorporates exogenous DNA. Optimal amounts and sources of donor DNA (chromosomal, amplicon, or replicative plasmid), concentrations of synthetic competence-stimulating peptide, and transformation media were assessed. Results: A semi-defined medium showed much improved results for response to the competence stimulating peptide when compared to rich media. The use of a donor amplicon with large homology flanking regions also provided higher transformation rates. Overall, an increase of transformation efficiencies from 0.001% or less to over 30% was achieved with the developed protocol. We further describe the construction of a markerless mutant based on this high efficiency strategy. Conclusion: We optimized competence development in S. mitis, by use of semi-defined medium and appropriate concentrations of synthetic competence factor. Combined with the use of a large amplicon of donor DNA, this method allowed easy and direct editing of the S. mitis genome, broadening the spectrum of possible downstream applications of natural transformation in this species.

Se alle arbeider i NVA

• Ma, Siyao; Hong, Quan Nha; Levine, Alissa; Benali, Safaë; Petersen, Fernanda Cristina & Dawson, Aimee [Vis alle 11 forfattere av denne artikkelen] (2026). Antimicrobial Resistance Awareness and One Health Understanding among Dental Students in Quebec. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk; Lunde, Tracy Munthali; Sribasgaran, Biramitha; Ghafoor, Saba & Al-Haroni, Mohammed [Vis alle 9 forfattere av denne artikkelen] (2026). Mobile Genetic Elements Drive Antibiotic Resistance in Oral Streptococci. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg; Junges, Roger & Shawrob, Kazi Shefaul Mulk (2025). External stimuli modulating the development of competence in Streptococcus constellatus. Fulltekst i vitenarkiv
• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Salvadori, Gabriela; Gladstone, Rebecca Ashley & Junges, Roger (2025). Global Dynamics of Antibiotic Resistance in Streptococcus pneumoniae. Fulltekst i vitenarkiv
• Petersen, Fernanda Cristina; Nicolau, Belinda Farias & Junges, Roger (2025). Antimicrobial Resistance in Oral Health Care: A Global Call to Action. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk & Junges, Roger (2025). Subinhibitory Concentrations of Antibiotics Promotes Natural Transformation in Streptococcus constellatus. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk; Petersen, Fernanda Cristina & Junges, Roger (2024). Horizontal gene transfer and antibiotic resistance: activation of the competence system for DNA uptake in Streptococcus constellatus. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg & Junges, Roger (2024). The natural transformation system of Streptococcus constellatus. Fulltekst i vitenarkiv Vis sammendrag

  Streptococcus constellatus is a member of the anginosus group of streptococci (SAG) and it colonizes most notably the oral cavity and the gastrointestinal tract, being frequently involved in infections forming abscesses. S. constellatus has been shown to be able to acquire and incorporate foreign exogenous DNA through natural transformation; however, no functional analyses nor comprehensive assessment of the system have yet been performed. Thus, our aim was to characterize the natural transformation system and its downstream effects in S. constellatus and investigate environmental factors coordinating its natural transformation system.

• Junges, Roger (2024). Fighting the antimicrobial resistance threat in the Asia Pacific region by engaging dental students as important stakeholders. Fulltekst i vitenarkiv
• Shawrob, Kazi; Dhariwal, Achal; Silva, Gabriela Salvadori Da; Petersen, Fernanda Cristina & Junges, Roger (2024). Mapping antibiotic resistance patterns in Streptococcus pneumoniae. Fulltekst i vitenarkiv
• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Silva, Gabriela Salvadori Da; Petersen, Fernanda Cristina & Junges, Roger (2024). Mapping antibiotic resistance patterns in Streptococcus pneumoniae. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk; Petersen, Fernanda Cristina & Junges, Roger (2024). Incorporating antibiotic resistance through natural transformation in Streptococcus constellatus. Fulltekst i vitenarkiv
• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Silva, Gabriela Salvadori Da; Petersen, Fernanda Cristina & Junges, Roger (2024). Insights into multidrug resistance in Streptococcus pneumoniae. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg & Junges, Roger (2024). Characterization of the Natural Transformation System in Streptococcus constellatus. Fulltekst i vitenarkiv
• Junges, Roger (2023). Educating the next generation of dental prescribers. Fulltekst i vitenarkiv
• Smith, Clay; Nicolau, Belinda Farias; Junges, Roger; Petersen, Fernanda Cristina & Levine, Alissa (2023). Perceptions, Attitudes, Beliefs, and Recommendations Regarding Antimicrobial Resistance and Antibiotic Prescriptions: A Qualitative Study Among McGill DMD Students. Fulltekst i vitenarkiv
• McLaughlin, Kendra J.; Junges, Roger; Levine, Alissa; Petersen, Fernanda Cristina & Nicolau, Belinda Farias (2023). Exploring Dental Professionals' Attitudes Toward Antimicrobial Resistance and Their Role in Mitigating Health Risks. Fulltekst i vitenarkiv
• Junges, Roger (2022). A deep dive into oral health, microbes, and the ocean. Fulltekst i vitenarkiv
• Brar, Navdeep Kaur; Junges, Roger; Hakansson, Anders P. & Petersen, Fernanda Cristina (2022). General IADR conference. The Impact of HAMLET, a Human-Milk Protein Complex, on the Ecology of the Oral Microbiome. Fulltekst i vitenarkiv
• Junges, Roger (2022). How to overcome challenges in dental education on antimicrobial resistance? Fulltekst i vitenarkiv
• Ghafoor, Saba; Salvadori, Gabriela; Ricomini-Filho, Antônio Pedro; Marques, Dalton; Petersen, Fernanda Cristina & Nicolau, Belinda Farias [Vis alle 8 forfattere av denne artikkelen] (2022). Dental education on antibiotic resistance: a qualitative analysis of the educators’ perspectives. Fulltekst i vitenarkiv
• Junges, Roger (2022). The role of dentistry in the fight against antimicrobial resistance. Fulltekst i vitenarkiv
• Junges, Roger (2022). Global challenges in dental education on antimicrobial resistance. Fulltekst i vitenarkiv
• Ghafoor, Saba; Salvadori, Gabriela; Ricomini-Filho, Antônio Pedro; Marques, Dalton; Petersen, Fernanda Cristina & Nicolau, Belinda Farias [Vis alle 8 forfattere av denne artikkelen] (2022). Dental education on antibiotic resistance. Fulltekst i vitenarkiv
• Brar, Navdeep Kaur; Dhariwal, Achal; Junges, Roger; Håkansson, Anders & Petersen, Fernanda Cristina (2022). Potential of HAMLET, a human milk protein-lipid complex, to modulate ecological changes in the oral microbiome induced by amoxicillin. Fulltekst i vitenarkiv
• Brar, Navdeep Kaur; Dhariwal, Achal; Åmdal, Heidi Aarø; Junges, Roger; Salvadori, Gabriela & Petersen, Fernanda Cristina (2022). The Impact of Ampicillin on the Oral Microbiome and Resistome. Fulltekst i vitenarkiv
• Rajar, Polona; Dhariwal, Achal; Salvadori, Gabriela; Junges, Roger; Åmdal, Heidi Aarø & Berild, Dag [Vis alle 12 forfattere av denne artikkelen] (2022). Microbial DNA extraction of high-host content and low biomass samples: optimized protocol for nasopharynx metagenomic studies. Fulltekst i vitenarkiv Vis sammendrag

  Low microbial biomass and high human DNA content in nasopharyngeal aspirate samples hinder comprehensive characterization of microbiota and resistome. We obtained samples from premature infants, a group with increased risk of developing respiratory disorders and infections, and consequently frequent exposure to antibiotics. Our aim was to devise an optimal protocol for handling nasopharyngeal aspirates from premature infants, focusing on host DNA depletion and microbiome and resistome characterization. Three depletion and three DNA extraction protocols were compared, using RT-PCR and whole metagenome sequencing to determine the efficiency of human DNA removal, taxonomic profiling and assignment of antibiotic resistance genes. Protocols were tested using mock communities, as well as pooled and individual patient samples. The only extraction protocol to retrieve the expected DNA yield from mock community samples was based on a lytic method to improve Gram positive recovery (MasterPure™). Only samples depleted with MolYsis™ showed satisfactory, but varied reduction in host DNA content, in both pooled and individual patient samples, allowing for microbiome and resistome characterisation (host DNA content from 15% to 98%). PCR results were indicative of achieved microbial enrichment. Despite high human DNA and low microbial biomass content in nasopharynx aspirates of preterm infants, we were able to reduce host DNA content to levels compatible with downstream shotgun metagenomic analysis, including bacterial species identification and coverage of antibiotic resistance genes. Whole metagenomic sequencing of microbes colonizing the nasopharynx may contribute to explaining the possible role of airway microbiota in respiratory conditions and reveal carriage of antibiotic resistance genes.

• Ghafoor, Saba; Petersen, Fernanda Cristina & Junges, Roger (2021). The global challenge of dental education on antibiotic resistance: a qualitative interview study. Fulltekst i vitenarkiv
• Silva, Guilherme Vidal; Justen, Michelli; Lamers, Juliana Maciel de Souza; Junges, Roger & Toassi, Ramona Fernanda Ceriotti (2021). Patterns of further education and employment of dental graduates: a twelve-year analysis from 2007 to 2019. Fulltekst i vitenarkiv
• Brar, Navdeep Kaur; Junges, Roger; Hakansson, Anders P. & Petersen, Fernanda Cristina (2021). The Impact of HAMLET, a Human-Milk Protein Complex, on the Ecology of the Oral Microbiome. Fulltekst i vitenarkiv
• Petersen, Fernanda Cristina; Dhariwal, Achal; Bråten, Lars Christian Haugli; Sturød, Kjersti; Junges, Roger & Salvadori, Gabriela [Vis alle 10 forfattere av denne artikkelen] (2021). Off-target impact of long-term amoxicillin treatment. Fulltekst i vitenarkiv
• Correa, Helena W.; Lamers, Juliana Maciel de Souza; Junges, Roger; Rösing, Cassiano Kuchenbecker; Samuel, Susana MW & Toassi, Ramona Fernanda Ceriotti (2020). The formation process of healthcare professionals during post-graduation: an analysis of dental students. Fulltekst i vitenarkiv
• Junges, Roger (2020). Antibiotic Stewardship in Dental Education. Fulltekst i vitenarkiv
• Dhariwal, Achal; Petersen, Fernanda Cristina; Junges, Roger & Chen, Tsute (2020). ResistoXplorer: a web-based tool for visual, statistical and exploratory data analysis of resistome data. Fulltekst i vitenarkiv
• Junges, Roger (2019). Antimicrobial stewardship in oral health care: are we doing our part? Fulltekst i vitenarkiv
• Pagotto, LL; Junges, Roger; Salvadori, Gabriela; Petersen, Fernanda Cristina & Filho, AP Ricomini (2019). Inhibition of Streptococcus mutans competence by chlorhexidine gluconate. Fulltekst i vitenarkiv
• Junges, Roger (2019). ComRS systems in the mitis group of streptococci. Fulltekst i vitenarkiv
• Junges, Roger (2019). Uncovering complex microbiome activities via metatranscriptomics during 24 hours of oral biofilm assembly and maturation. Fulltekst i vitenarkiv
• Pagotto, LL; Junges, Roger; Salvadori, Gabriela; Petersen, Fernanda Cristina & Filho, Antonio Pedro Ricomoni (2019). Inhibition of Streptococcus mutans competence by chlorhexidine gluconate. Fulltekst i vitenarkiv
• Junges, Roger (2019). Identification of a ComRS-like regulator system in the mitis group of streptococci. Fulltekst i vitenarkiv
• Junges, Roger; Salvadori, Gabriela; Chen, Tsute & Petersen, Fernanda Cristina (2019). Identification of a ComRS-like regulator system in the mitis group of streptococci. Fulltekst i vitenarkiv
• Dhariwal, Achal; Junges, Roger & Petersen, Fernanda Cristina (2019). Exploratory analysis and Visualization of resistome data. Fulltekst i vitenarkiv Vis sammendrag

  Abstract: Recently, antimicrobial resistance (AMR) has gained everybody’s attention at a global level due to its impact on public health. Nation-wide surveillance efforts have been going on for characterization of these resistance determinants responsible for AMR. Due to advancements in metagenomics, comprehensive databases have been already established providing hierarchical information such as class, group and mechanism of these antibiotic resistance genes (ARGs). Additionally, some recently developed tools are also able to quantify the abundance of these ARGs present in any metagenomic sample. However, it is still challenging to perform bioinformatics analysis and interpretation of such data. Further, there is no such specific tool developed to support comprehensive downstream analysis and visualization from resistome data. As a result, we are aiming to develop ResistoAnalyst, a user-friendly web-based tool that integrates recent advancements in visualization and statistics techniques, integrated with several comprehensive databases, to enable comprehensive analysis of resistome data generated from metagenomics studies. Development of such tool will enable most clinicians, bench researchers to better understand, and generate hypothesis from their own data in real time. Additionally, ResistoAnalyst will be a valuable resource for sequence-based surveillance and monitoring of antibiotic usage and resistome development.

• Junges, Roger (2019). A ComRS-like regulator system in the mitis group of streptococci that regulates bacteriocin production. Fulltekst i vitenarkiv Vis sammendrag

  Abstract: Streptococci are particularly abundant in the oral cavity. Species in this genus trigger the natural transformation system, which enables them to acquire exogenous DNA and recombine, through the products of different gene clusters: comCDE and comRS. While members of the mitis groups of streptococci present the activation via comCDE, here we investigated the presence and functionality of comRS-like systems in these species. Homology search indicated the presence of putative ComRS systems in the mitis group, including Streptococcus mitis and Streptococcus gordonii. One of the S. mitis candidates was selected for mechanistic studies. Downstream of the ComR regulator gene, a comS-like gene coding for a putative pheromone was identified, and it contained a double-tryptophan as traditionally found in type II XIPs (sigX-inducing peptide). However, no conserved ComR-box was identified upstream of sigX, which encodes the master regulator of competence for natural transformation, indicating that the ComRS system was not involved in competence activation. Induction of the system using the synthetic XIP-like peptide revealed that the system promoted activation of a bacteriocin cluster. Altogether, we have identified a ComRS-like system in the mitis group that regulates bacteriocin production. This is the first description of a ComRS-like system that does not seem to regulate competence. In addition, the target of the bacteriocin produced by this oral bacterium poses as an interesting target for further studies.

• Junges, Roger; Petersen, Fernanda Cristina; Egija, Zaura; Lemos, José A. & Merritt, Justin (2018). Environmental and antibiotic stress on oral bacteria: a target for new therapies. Fulltekst i vitenarkiv
• Junges, Roger & Petersen, Fernanda Cristina (2018). Eavesdropping on bacterial conversations: what are they doing and do they understand each other? Fulltekst i vitenarkiv
• Morrison, Donald A.; Jimenez, Med; Cowley, Lauren A.; Junges, Roger; Petersen, Fernanda Cristina & Hanage, William P. (2018). Genomic signature of natural genetic transformation shared by S. pneumoniae and S. pyogenes. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger; Åmdal, Heidi Aarø; Chen, Tsute; Morrison, Donald A & Petersen, Fernanda Cristina (2018). Molecular Characterization of Genetic Competence in Streptococcus mitis. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger; Åmdal, Heidi Aarø; Chen, Tsute; Morrison, Donald A & Petersen, Fernanda Cristina (2018). Insights into regulatory pathways of competence development in Streptococcus mitis type strain and SK321. Fulltekst i vitenarkiv
• Sturød, Kjersti; Salvadori, Gabriela; Junges, Roger & Petersen, Fernanda Cristina (2018). Antibiotic Induced Streptococcal Competence Not Always Correlate with Transformability. Fulltekst i vitenarkiv
• Junges, Roger & Petersen, Fernanda Cristina (2018). Interspecies cell-to-cell communication in the mitis group of streptococci. Fulltekst i vitenarkiv
• Junges, Roger & Petersen, Fernanda Cristina (2018). Rgg/SHP cross-communication in the mitis group of streptococci. Fulltekst i vitenarkiv
• Junges, Roger; Sturød, Kjersti; Salvadori, Gabriela; Åmdal, Heidi Aarø; Chen, Tsute & Petersen, Fernanda Cristina (2018). Interspecies activation of a virulent pathway by an oral commensal. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger; Morrison, Donald A. & Petersen, Fernanda Cristina (2017). High efficiency genetic transformation in encapsulated pneumococcus. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger & Petersen, Fernanda Cristina (2017). A Competence-Induced Bacteriocin Reduces Growth of Oral Pathogenic Bacteria. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger; Chen, Tsute & Petersen, Fernanda Cristina (2017). A Competence-Induced Bacteriocin Reduces Growth of Oral Pathogenic Bacteria. Fulltekst i vitenarkiv
• Junges, Roger; Salvadori, Gabriela; Chen, Tsute; Åmdal, Heidi A.; N., Periselneris Jimstan & S., Brown Jeremy [Vis alle 7 forfattere av denne artikkelen] (2017). A bacterial pheromone system regulates biofilm formation and colonization. Fulltekst i vitenarkiv
• Cowley, Lauren A.; Petersen, Fernanda Cristina; Junges, Roger; Hanage, William P & Morrison, Donald A. (2017). Co-culture of S. pneumoniae strains fosters large recombination events. Fulltekst i vitenarkiv
• Cowley, Lauren A.; Petersen, Fernanda Cristina; Junges, Roger; Hanage, William P & Morrison, Donald A. (2017). Large recombination events readily occurring in biofilm cultures of Streptococcus pneumoniae. Fulltekst i vitenarkiv
• Junges, Roger; Salvadori, Gabriela; Sudhanshu, Shekhar; Åmdal, Heidi A.; N., Periselneris Jimstan & Chen, Tsute [Vis alle 8 forfattere av denne artikkelen] (2017). An Rgg/SHP quorum sensing system reduces virulence and fitness in Streptococcus pneumoniae. Fulltekst i vitenarkiv
• Junges, Roger; Salvadori, Gabriela; Åmdal, Heidi A.; Morrison, Donald A.; Chen, Tsute & Petersen, Fernanda Cristina (2016). Global response of Streptococcus mitis to the competence-stimulating peptide. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger; Åmdal, Heidi A.; Chen, Tsute & Petersen, Fernanda Cristina (2016). Transcriptome response of Streptococcus mitis to the competence pheromone (Hatton Award representation). Fulltekst i vitenarkiv
• Junges, Roger (2016). Overcoming barriers to genome editing of oral streptococci. Fulltekst i vitenarkiv
• Junges, Roger; Khan, Rabia; Åmdal, Heidi A.; Morrison, Donald A. & Petersen, Fernanda Cristina (2016). Markerless Genome Editing in Oral Streptococci. Fulltekst i vitenarkiv
• Junges, Roger (2016). Overcoming barriers to genome editing of oral streptococci. Fulltekst i vitenarkiv
• Salvadori, Gabriela; Junges, Roger; Chen, Tsute; Morrison, Donald A. & Petersen, Fernanda Cristina (2016). High-resolution profiles of the CSP signaling pathway in Streptococcus mitis SK321 and NCTC12261T. Fulltekst i vitenarkiv
• Junges, Roger (2016). Rgg-type regulators in streptococci. Fulltekst i vitenarkiv

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