Kazi Shefaul Mulk Shawrob

• 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. Full text in Research Archive Show summary

  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. [Show all 9 contributors for this article] (2026). Mapping Antibiotic Resistance Determinants in Oral Streptococci. Journal of Dental Research. ISSN 0022-0345. doi: 10.1177/00220345261462871. Full text in Research Archive Show summary

  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.

• 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. Full text in Research Archive Show summary

  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.

• Kibria, M.M.; Islam, N.; Billah, M.; Shawrob, Kazi Shefaul Mulk; Rumi, M.H. & Siddiki, AMAM Zonaed (2020). Complete mitochondrial genome sequence of Catla catla (Hamilton, 1822) from the Halda river of Bangladesh. Mitochondrial DNA Part B: Resources. 5(3), p. 3233–3235. doi: 10.1080/23802359.2020.1809542. Full text in Research Archive Show summary

  Catla (Catla catla) is one of the fastest-growing major carp found in South Asia as well as Bangladesh. Catla catla is the second most popular indigenous carp species in the freshwater aquaculture industry of Bangladesh due to its relatively good taste and high market price. In this study, we disclosed the complete mitochondrial genome sequence of Bangladeshi Catla fish from Halda river located in Chittagong. The circular mitogenome of Catla catla is 16,597 bp in length and nucleotide composition is AT-based (72%), contains 37 genes including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a D-loop (control region).

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• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk; Lunde, Tracy Munthali; Sribasgaran, Biramitha; Ghafoor, Saba & Al-Haroni, Mohammed [Show all 9 contributors for this article] (2026). Mobile Genetic Elements Drive Antibiotic Resistance in Oral Streptococci. Full text in Research Archive
• Sagen, Andreas Solberg; Junges, Roger & Shawrob, Kazi Shefaul Mulk (2025). External stimuli modulating the development of competence in Streptococcus constellatus. Full text in Research Archive
• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Salvadori, Gabriela; Gladstone, Rebecca Ashley & Junges, Roger (2025). Global Dynamics of Antibiotic Resistance in Streptococcus pneumoniae. Full text in Research Archive
• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk & Junges, Roger (2025). Subinhibitory Concentrations of Antibiotics Promotes Natural Transformation in Streptococcus constellatus. Full text in Research Archive
• 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. Full text in Research Archive
• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Silva, Gabriela Salvadori Da; Petersen, Fernanda Cristina & Junges, Roger (2024). Mapping antibiotic resistance patterns in Streptococcus pneumoniae. Full text in Research Archive
• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk; Petersen, Fernanda Cristina & Junges, Roger (2024). Incorporating antibiotic resistance through natural transformation in Streptococcus constellatus. Full text in Research Archive
• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Silva, Gabriela Salvadori Da; Petersen, Fernanda Cristina & Junges, Roger (2024). Insights into multidrug resistance in Streptococcus pneumoniae. Full text in Research Archive

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