Molecular typing of Staphylococcus aureus isolate responsible for staphylococcal poisoning incident in homemade food

oleh: Guerrino Macori, Alberto Bellio, Daniela Manila Bianchi, Silvia Gallina, Daniela Adriano, Fabio Zuccon, Francesco Chiesa, Pier Luigi Acutis, Francesco Casalinuovo, Lucia Decastelli

Format: Article
Diterbitkan: PAGEPress Publications 2016-06-01

Deskripsi

In October 2012, two persons fell ill with symptoms consistent with staphylococcal food poisoning after eating home-canned tuna fish and tomatoes. Laboratory investigation detected the enterotoxins in the home-canned tuna and molecular analysis of the isolated <em>Staphylococcus aureus</em> confirmed it carried toxin genes. Qualitative enzyme-linked immunosorbent assay and enzime linked fluorescent assay methods and quantitative assay identified the enterotoxins in the food leftovers, specifically staphylococcal enterotoxins type A (SEA) and D (SED), respectively 0.49 and 2.04 ng/g. The laboratory results are discussed considering the relation to the fish in oil, survival and heat resistance of <em>S. aureus</em>, and presumptive microbial contamination due to improper handling during home-canning procedures. This is the first reported cluster of foodborne illnesses due to staphylococcal enterotoxins in tuna in Italy. In this study, we reported cases described and analysed for their <em>spa</em>-type. Showing a high heterogeneity of isolates, <em>spa</em>-type t13252 is correlated in a node of the minimum spanning tree and it has never been reported as responsible for foodborne outbreak. This case underlines the importance of risk communication and dissemination of home-canning guidelines to reduce the incidence of foodborne outbreaks caused by homemade conserves.