Molecular subtyping of Staphylococcus aureus from an outbreak associated with a food handler

Abstract

On 6 May 2000, a staphylococcal food poisoning outbreak occurred at a high school, affecting 10 of the 356 students who attended the breakfast. Twenty-seven Staphylococcus aureus isolates, producing enterotoxin A (SEA), SEB-, or non-SEA-E, were recovered from 7 patients, 2 food handlers and left-overs. To investigate the outbreak, we genotyped the isolates by using pulsed-field gel electrophoresis (PFGE) and three PCR-based techniques: inter-IS256 PCR typing, protein A gene (spa) typing, and coagulase gene restriction profile (CRP) analysis. Our results show that PFGE was the most discriminatory technique, whereas the three PCR-based techniques were insufficient in the discriminatory power to distinguish the S. aureus isolates from the outbreak. Based on the enterotoxin-producing types and the results of genotyping, three distinct types of strains (A1111, B2221 and N3221) were designated. Both the A1111 and B2221 strains were found in the specimens from the patients and a hand lesion of a food handler, suggesting that the source of contamination for the outbreak was most likely originated from a food handler.

Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Workers in the Food Industry

“…Another SFP outbreak reported recently was caused by an enterotoxin A and I producing strain, which was introduced most likely by a food handler (Gallina et al, 2013). Similarly, Wei et al were able to trace back enterotoxigenic outbreak strains carrying sea and seb, respectively, to the hand lesion of a food handler in a cafeteria (Wei and Chiou, 2002). However, in a large percentage of outbreaks the initial source of contamination remains unknown.…”

Staphylococcus aureusand its food poisoning toxins: characterization and outbreak investigation

“…They were identified according to four biochemical tests (staphylokinase, ß-haemolysin production, coagulation of bovine plasma and growth type on crystal violet agar) following the simplified biotyping scheme described by Devriese (1984). To suggest the source of contamination (animal or human origins), molecular-based methods have been used by various authors to study the food poisoning outbreaks (Chiou et al, 2000;Shimizu et al, 2000;Wei & Chiou, 2002;Kerouanton et al, 2007;Ostyn et al, 2010). Later, a poultry-like biotype associated with meat products and meat workers was tentatively designated as a 'slaughterhouse' biotype by Isigidi et al (1990).…”

Outbreak of Infection with Hepatitis A Virus (HAV) Associated with a Foodhandler and Confirmed by Sequence Analysis Reveals a New HAV Genotype IB Variant

“…Foodhandlers have been widely recognized as a source of infection during several foodborne outbreaks (1,6,11,18,19,24). In addition, there have been many reports of HAV epidemics, analyzed through epidemiologic studies, that have been associated with foods contaminated by infected foodhandlers (5,14,23).…”