Browsing by Author "Kumari, M"

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    Antibiotic resistance, biofilm formation, and virulence genes of Streptococcus agalactiae serotypes of Indian origin
    (2023) Verma, S; Kumari, M; Pathak, A; Yadav, V; Johri, AK; Yadav, P
    Group B Streptococcus (GBS) is a causative agent of various infections in newborns, immunocompro mised (especially diabetic) non-pregnant adults, and pregnant women. Antibiotic resistance profiling can provide insights into the use of antibiotic prophylaxis against potential GBS infections. Virulence factors are responsible for host–bacteria interactions, pathogenesis, and biofilm development strategies. The aim of this study was to deter mine the biofilm formation capacity, presence of virulence genes, and antibiotic susceptibility patterns of clinical GBS isolates. Results The resistance rate was highest for penicillin (27%; n = 8 strains) among all the tested antibiotics, which indi cates the emergence of penicillin resistance among GBS strains. The susceptibility rate was highest for ofloxacin (93%; n = 28), followed by azithromycin (90%; n = 27). Most GBS strains (70%; n = 21) were strong biofilm producers and the rest (30%; n = 9) were moderate biofilm producers. The most common virulence genes were cylE (97%), pavA (97%), cfb (93%), and lmb (90%). There was a negative association between having a strong biofilm formation phenotype and penicillin susceptibility, according to Spearman’s rank correlation analysis. Conclusion About a third of GBS strains exhibited penicillin resistance and there was a negative association between having a strong biofilm formation phenotype and penicillin susceptibility. Further, both the strong and moderate biofilm producers carried most of the virulence genes tested for, and the strong biofilm formation phenotype was not associated with the presence of any virulence genes.
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    Antibiotic resistance, bioflm formation, and virulence genes of Streptococcus agalactiae serotypes of Indian origin
    (2023) Verma, S; Kumari, M; Pathak, A; Yadav, V; Johri, A
    Abstract Background Group B Streptococcus (GBS) is a causative agent of various infections in newborns, immunocompro mised (especially diabetic) non-pregnant adults, and pregnant women. Antibiotic resistance profling can provide insights into the use of antibiotic prophylaxis against potential GBS infections. Virulence factors are responsible for host–bacteria interactions, pathogenesis, and bioflm development strategies. The aim of this study was to deter mine the bioflm formation capacity, presence of virulence genes, and antibiotic susceptibility patterns of clinical GBS isolates. Results The resistance rate was highest for penicillin (27%; n=8 strains) among all the tested antibiotics, which indi cates the emergence of penicillin resistance among GBS strains. The susceptibility rate was highest for ofoxacin (93%; n=28), followed by azithromycin (90%; n=27). Most GBS strains (70%; n=21) were strong bioflm producers and the rest (30%; n=9) were moderate bioflm producers. The most common virulence genes were cylE (97%), pavA (97%), cfb (93%), and lmb (90%). There was a negative association between having a strong bioflm formation phenotype and penicillin susceptibility, according to Spearman’s rank correlation analysis. Conclusion About a third of GBS strains exhibited penicillin resistance and there was a negative association between having a strong bioflm formation phenotype and penicillin susceptibility. Further, both the strong and moderate bioflm producers carried most of the virulence genes tested for, and the strong bioflm formation phenotype was not associated with the presence of any virulence genes.
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    G-Quadruplex Structures in Bacteria: Biological Relevance and Potential as an Antimicrobial Target
    (2021-06) Yadav, P; Kim, N; Kumari, M
    DNA strands consisting of multiple runs of guanines can adopt a nonca nonical, four-stranded DNA secondary structure known as G-quadruplex or G4 DNA. G4 DNA is thought to play an important role in transcriptional and translational regulation of genes, DNA replication, genome stability, and oncogene expression in eukaryotic genomes. In other organisms, including several bacterial pathogens and some plant species, the biological roles of G4 DNA and G4 RNA are starting to be explored. Recent investigations showed that G4 DNA and G4 RNA are generally con served across plant species. In silico analyses of several bacterial genomes identified putative guanine-rich, G4 DNA-forming sequences in promoter regions. The sequen ces were particularly abundant in certain gene classes, suggesting that these highly diverse structures can be employed to regulate the expression of genes involved in secondary metabolite synthesis and signal transduction. Furthermore, in the patho gen Mycobacterium tuberculosis, the distribution of G4 motifs and their potential role in the regulation of gene transcription advocate for the use of G4 ligands to develop novel antitubercular therapies. In this review, we discuss the various roles of G4 structures in bacterial DNA and the application of G4 DNA as inhibitors or therapeu tic agents to address bacterial pathogens.