Browsing by Author "Verma, S"

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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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    Deciphering Streptococcal Biofilms
    (2020-11) Yadav, P; Verma, S; Bauer, R
    Streptococci are a diverse group of bacteria, which are mostly commensals but also cause a considerable proportion of life-threatening infections. They colonize many different host niches such as the oral cavity, the respiratory, gastrointestinal, and urogenital tract. While these host compartments impose different environmental conditions, many streptococci form biofilms on mucosal membranes facilitating their prolonged survival. In response to environmental conditions or stimuli, bacteria experience profound physiologic and metabolic changes during biofilm formation. While investigating bacterial cells under planktonic and biofilm conditions, various genes have been identified that are important for the initial step of biofilm formation. Expression patterns of these genes during the transition from planktonic to biofilm growth suggest a highly regulated and complex process. Biofilms as a bacterial survival strategy allow evasion of host immunity and protection against antibiotic therapy. However, the exact mechanisms by which biofilm-associated bacteria cause disease are poorly understood. Therefore, advanced molecular techniques are employed to identify gene(s) or protein(s) as targets for the development of antibiofilm therapeutic approaches. We review our current understanding of biofilm formation in different streptococci and how biofilm production may alter virulence-associated characteristics of these species. In addition, we have summarized the role of surface proteins especially pili proteins in biofilm formation. This review will provide an overview of strategies which may be exploited for developing novel approaches against biofilm-related streptococcal infections.