Virulence and intermediate resistance to high‐end antibiotic (teicoplanin) among coagulase‐negative staphylococci sourced from retail market fish

K.H. Muneeb, S. Sudha, G.K. Sivaraman, Bibek Shome, Jennifer Cole, Mark Holmes

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This study reports the distribution of enterotoxigenic determinants among staphylococci and the susceptibility of staphy- lococci to various classes of antibiotics. We observed all the isolates as resistant to beta-lactam antibiotics and a few as resistant to non-beta-lactam antibiotics such as clindamycin (47.4%), erythromycin (44.7%), gentamicin (23.7%), norfloxacin (34.2%), tetracycline (26.3%), trimethoprim-sulfamethoxazole (15.8%) etc. The resistance of S. sciuri (n = 1) and S. haemo- lyticus (n = 1) to rifampicin and intermediate resistance of S. gallinarum (n = 2) to teicoplanin, a high-end antibiotic, are also observed in this study. The multidrug-resistance (≥ 3 classes of antibiotics) was recorded in 23 (60.5%) isolates. The virulomes such as sea, seb, seg and sei were identified predominantly in S. haemolyticus. Surprisingly, certain isolates which were phenotypically confirmed as biofilm-producers by Congo red agar (CRA) test did not harbor biofilm-associated loci. This implies the protein-mediated mechanism of biofilm formation as an alternative to polysaccharide intercellular adhesin (PIA) in staphylococci. However, icaAD locus which encodes PIA was identified in 10 (26.3%) isolates and the eno locus, encoding elastin-binding protein which can accelerate the biofilm production, is identified in all the isolates. The posses- sion of type V SCCmec elements by the S. haemolyticus (15.8%) raised the concern about the rapid dissemination of mecA gene to other species of staphylococci including the virulent S. aureus. In short, this study acknowledges the toxigenicity of coagulase-negative staphylococci (CoNS). Through this study, surveillance of antimicrobial resistance and transference of virulomes in staphylococci is warranted.
Original languageEnglish
Pages (from-to)5695-5702
Number of pages8
JournalArchives of microbiology
Publication statusPublished - 1 Sept 2021


  • Coagulase-negative staphylococci
  • Virulence genes
  • mecA gene
  • Type V SCCmec elements
  • Enterotoxins

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