Mass spectrometry and multiplex antigen assays to assess microbial quality and toxin production of Staphylococcus aureus strains isolated from clinical and food samples.

Abstract

The aim of our study was to investigate the microbial quality of meat products and on some clinical samples in Abidjan focused on Staphylococcus genus and the toxin production profile of Staphylococcus aureus (S. aureus) isolated. Bacteria were collected from 240 samples of three meat products sold in Abidjan and 180 samples issued from clinical infections. The strains were identified by both microbiological and MALDI-TOF-MS methods. The susceptibility to antibiotics was determined by the disc diffusion method. The production of Panton-Valentine Leukocidin, LukE/D, and epidermolysins was screened using radial gel immunodiffusion. The production of staphylococcal enterotoxins and TSST-1 was screened by a Bio-Plex Assay. We observed that 96/240 of meat samples and 32/180 of clinical samples were contaminated by Staphylococcus. Eleven species were isolated from meats and 4 from clinical samples. Forty-two S. aureus strains were isolated from ours samples. Variability of resistance was observed for most of the tested antibiotics but none of the strains displays a resistance to imipenem and quinolones. We observed that 89% of clinical S. aureus were resistant to methicillin against 58% for those issued from meat products. All S. aureus isolates issued from meat products produce epidermolysins whereas none of the clinical strains produced these toxins. The enterotoxins were variably produced by both clinical and meat product samples.