Presence of genes encoding enterotoxins in Staphylococcus aureus isolates recovered from food, food establishment surfaces and cases of foodborne diseases

Abstract

The aim of this study was to describe the microbiological characteristics and profile of genes encoding enterotoxins in 95 Staphylococcus aureus isolates obtained between April 2011 and December 2014 from foodstuffs, persons and surfaces of retail food stores. After microbiological identification and antimicrobial susceptibility testing, polymerase chain reactions (PCR) were performed, targeting sea, seb, sec, sed and see genes that code for classical enterotoxins (ET) A-E, and three additional genes: seg, seh and sei, coding for so-called "new enterotoxins" G, H and I. The isolates were characterized by Pulsed Field Gel Electrophoresis (PFGE), and five selected isolates were further analyzed through Multi Locus Sequence Typing (MLST). It is noteworthy that 54.7% of the examined isolates harbored one or more of the investigated ET gene types. Most positive isolates carried more than one ET gene up to five types; seg was the most frequent ET gene, followed by sei. Five enterotoxin-coding isolates also coded for some antimicrobial resistance genes. Two of them, and four additional non-enterotoxic isolates carried erm genes expressing inducible clindamycin resistance. PFGE-types were numerous and diverse, even among enterotoxin-coding strains, because most isolates did not belong to known foodborne outbreaks and the sampling period was long. MLST profiles were also varied, and a new ST 3840 was described within this species. ST 88 and ST 72 enterotoxin-coding isolates have been identified in other regions in association with foodborne outbreaks. This manuscript reports the first systematic investigation of enterotoxin genes in S. aureus isolates obtained from foodstuffs and infected people in Uruguay.

Occurrence and enterotoxin gene profiles of Staphylococcus aureus isolated from retail chicken meat

“…The 80 isolates of the present study were subjected to multiplex PCR protocol for 9 enterotoxin genes and the results revealed that 52.50% (42/80) of the isolates in the present study were enterotoxigenic harboring either one or more gene. Machado et al (2020) noted that 54.7% of the examined S. aureus isolates recovered from food, food handlers and contact surfaces from Uruguay harbored one or more of the investigated enterotoxin gene types. In similar lines, Sahin et al (2020) in Turkey and Li et al (2018) in the People's Republic of China indicated that 69% and 46% of the S. aureus isolates from raw chicken meat was positive for one or more toxin genes, respectively.…”

“…The 80 isolates of the present study were subjected to multiplex PCR protocol for 9 enterotoxin genes and the results revealed that 52.50% (42/80) of the isolates in the present study were enterotoxigenic harboring either one or more gene. Machado et al. (2020) noted that 54.7% of the examined S. aureus isolates recovered from food, food handlers and contact surfaces from Uruguay harbored one or more of the investigated enterotoxin gene types.…”

Occurrence of community-acquired Panton-Valentine leukocidin-producing and enterotoxin-producing methicillin-resistant staphylococci in companion dogs

“…The PCR was done with specific primers that targeted the prototypic enterotoxin B gene (Machado et al, 2020). Specific primers used for amplifying enterotoxin B gene were SEB-F (5ʹ-ACATGTAATTTTGATATTCGCACTG-3ʹ) and SEB-R (5′-TGCAGGCATCATGTCATACCA-3′), with amplicon size of 667 base pairs.…”

Prevalence of staphylococcal toxin in food contaminated by Staphylococcus spp.: Protocol for a systematic review with meta-analysis

“…Foodborne Diseases (FBD) have been considered one of the main public health problems worldwide, including in developed countries [ 5 , 6 ]. Besides that, they are important causes of morbidity and mortality and therefore an important obstacle to global socioeconomic development [ 6 , 7 ]. Investment in improving food safety management capacity may have significant economic and public health benefits [ 8 ].…”