AUTHOR=Roussel sophie , Felix Benjamin , Vingadassalon Noemie , Grout Joel , Hennekine Jacques-Antoine , Guillier Laurent , Auvray Frederic 

TITLE=Staphylococcus aureus strains associated with food poisoning outbreaks in France: comparison of different molecular typing methods, including MLVA

JOURNAL=Frontiers in Microbiology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.00882

DOI=10.3389/fmicb.2015.00882

ISSN=1664-302X

ABSTRACT=<p>Staphylococcal food poisoning outbreaks (SFPOs) are frequently reported in France. However, most of them remain unconfirmed, highlighting a need for a better characterization of isolated strains. Here we analyzed the genetic diversity of 112 <italic>Staphylococcus aureus</italic> strains isolated from 76 distinct SFPOs that occurred in France over the last 30 years. We used a recently developed multiple-locus variable-number tandem-repeat analysis (MLVA) protocol and compared this method with pulsed field gel electrophoresis (PFGE), <italic>spa</italic>-typing and carriage of genes (<italic>se</italic> genes) coding for 11 staphylococcal enterotoxins (i.e., SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI, SEJ, SEP, SER). The strains known to have an epidemiological association with one another had identical MLVA types, PFGE profiles, spa-types or <italic>se</italic> gene carriage. MLVA, PFGE and <italic>spa</italic>-typing divided 103 epidemiologically unrelated strains into 84, 80, and 50 types respectively demonstrating the high genetic diversity of <italic>S. aureus</italic> strains involved in SFPOs. Each MLVA type shared by more than one strain corresponded to a single spa-type except for one MLVA type represented by four strains that showed two different-but closely related-spa-types. The 87 enterotoxigenic strains were distributed across 68 distinct MLVA types that correlated all with <italic>se</italic> gene carriage except for four MLVA types. The most frequent <italic>se</italic> gene detected was <italic>sea</italic>, followed by <italic>seg</italic> and <italic>sei</italic> and the most frequently associated <italic>se</italic> genes were <italic>sea-seh</italic> and <italic>sea-sed-sej-ser</italic>. The discriminatory ability of MLVA was similar to that of PFGE and higher than that of spa-typing. This MLVA protocol was found to be compatible with high throughput analysis, and was also faster and less labor-intensive than PFGE. MLVA holds promise as a suitable method for investigating SFPOs and tracking the source of contamination in food processing facilities in real time.</p>