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.

Antimicrobial resistance of potential pathogenic strains isolated from eggs produced by informal farms and sold in Abidjan, Ivory Coast

“…Indeed, the presence of methicillin-resistant strains in foods was reported in Germany by van den Broek (2003). The detection of resistant Staphylococcus in this study is of concern for food safety as this genus encompasses pathogenic species and in particular Staphylococcus aureus which can be resistant to antibiotics such as oxacillin and can produce toxin (Baba-Moussa et al, 2011, Attien et al, 2014. In 2010, an EFSA study at Abidjan reported similar results by showing that the main reservoir of methicillin-resistant Staphylococcus are pigs, calves and broilers (EFSA, 2010).…”

Characterization of Human Type C Enterotoxin Produced by Clinical S. epidermidis Isolates

“…The resulting recombinant protein (rSEC epi ) was expressed and purified by affinity chromatography and the identity of the protein is confirmed by Western blot method as a ~27 kDa protein using rabbit affinity-purified S. aureus anti-enterotoxin C antibodies ( Figure 4 B) [ 28 ]. SEs are well-known to resist heating and digestive enzymes [ 28 , 29 , 30 ]. rSEC epi was able to keep 30% function after heating at 100 °C for 1 h as SEC aureus does ( Figure 5 and Figure 6 ), more or less, but it was less resistant than SEA, which resists beyond 8 h of heat treatment [ 15 ].…”

Staphylococcal Superantigens Spark Host-Mediated Danger Signals

“…Transmission of antibiotic-resistant strains between livestock and humans working with and/or consuming the former is a real problem, poorly understood to date ( 28 – 31 ). Furthermore, aerosol transmission of MRSA from farm animals or human patients in hospital wards, to humans, is also a scary reality ( 32 – 34 ).…”