PCR detection of Staphylococcal enterotoxins (SEs) N, O, P, Q, R, U, and survey of SE types in Staphylococcus aureus isolates from food-poisoning cases in Taiwan

Chiang, Yu-Cheng; Liao, Wanwen; Fan, Chin-Ming; Pai, Wan-Yu; Chiou, Chien-Shun; Tsen, Hau‐Yang

doi:10.1016/j.ijfoodmicro.2007.10.005

Cited by 134 publications

(50 citation statements)

References 31 publications

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“…Many S. aureus strains harboring only new SE genes have been isolated from food poisoning cases (21,(31)(32)(33). This fact suggests that new SEs with relatively weak emetic activities have the ability to cause food poisoning in humans.…”

Section: Resultsmentioning

confidence: 99%

Emetic Potentials of Newly Identified Staphylococcal Enterotoxin-Like Toxins

et al. 2013

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g Staphylococcal enterotoxins (SEs) are a common causative agent of food poisoning. Recently, many new SE-like (SEl) toxins have been reported, although the role of SEls in food poisoning remains unclear. In this study, the emetic potentials of SElK, SElL, SElM, SElN, SElO, SElP, and SElQ were assessed using a monkey-feeding assay. All the SEls that were tested induced emetic reactions in monkeys at a dose of 100 g/kg, although the numbers of affected monkeys were significantly smaller than the numbers that were affected after consuming SEA or SEB. This result suggests that these new SEs may play some role in staphylococcal food poisoning. Staphylococcal enterotoxins (SEs) are exotoxins that cause staphylococcal food poisoning in humans worldwide (1-4). Several classical types (SEA, SEB, SEC, SED, and SEE) have been characterized (1, 2, 5). Recently, SEG, SEH, SEI, SER, SES, and SET were identified as potential agents of food poisoning (6-10). In addition, new proteins (SE-like toxin J [SElJ], SElK, SElL, SElM, SElN, SElO, SElP, SElQ, SElU, SElV, and SElX) with amino acid sequences that are similar to those of the above-mentioned SEs have been identified (11)(12)(13)(14)(15)(16)(17)(18)(19). SEs are also known to be members of the superantigen family (3,20). During the last few decades, numerous studies have been conducted on the nature of SEs and their superantigenic activities (3,20). However, the emetic activities of these toxins have not been studied. To better understand the etiologic nature of staphylococcal food poisoning, the emetic potentials of SEls should be evaluated in a primate model.We demonstrated the emetic activities of SElK, SElL, SElM, SElN, SElO, SElP, and SElQ using a primate model (cynomolgus monkeys); the number of vomiting events, the time until the first vomiting event (latency period), and behavioral changes were recorded for each animal. We compared the emetic activities of classical and new SEs as well as the activities of three large groups of SEs that were grouped according to the similarity of their amino acid sequences. MATERIALS AND METHODS Preparation of SEls.To construct the SElK, SElL, SElM, SElN, SElO, and SElQ expression plasmids, PCR primers were designed to amplify the gene fragment corresponding to the mature forms of these SEls (Table 1). The selk and selq genes were amplified from genomic DNA of the Staphylococcus aureus S6 strain, which harbors the sea, seb, selk, and selq genes (21). The sell gene was amplified from genomic DNA of the S. aureus bov1117 strain (harboring sea, sec, sell, sed, selj, selr, and tst-1), isolated from cow's milk, and the selm, seln, and selo genes were amplified from genomic DNA of the S. aureus Fukuoka 2 strain (21, 22). The PCR products were digested with BamHI and EcoRI or SalI and then subcloned into a pGEX6P-1 glutathione S-transferase (GST) fusion expression vector. These clones were designated pKKX (including the selk gene), pKLX (including the sell gene), pKMX (including the selm gene), pKNX (including the seln gene), pKOX (includin...

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Section: Resultsmentioning

confidence: 99%

Emetic Potentials of Newly Identified Staphylococcal Enterotoxin-Like Toxins

et al. 2013

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“…aureus isolates from subclinical mastitis and kareish cheese. Multiplex PCR for 10 S. aureus isolates (1-4 isolated from subclinical mastitis; 5-10 from kareish cheese), the sea genes were positive in 6 samples (2, 3, 5, 6, 7 and 10) at 102 bp ; the seb genes detected in 5 samples (1,3,7,8,9) at 164 bp; the see detected in 6 samples (2,3,5,6,7,10) at 209 bp, with no detection for sec and sed genes at 451 bp and 278 bp respectively.…”

Section: Discussionmentioning

confidence: 99%

“…Regarding food poisoning outbreaks, enterotoxins of S. aureus considered the most famous detecting in foods poisoning in human [6]. Thus assured via consumption of contaminated food products and milk products by S. aureus toxins [7]. In generally, early study of [8] reported that 14% to 40% of all human food poisoning outbreaks were associated with staphylococcal enterotoxins, that manifested at first by sudden onset of fever, vomiting, nausea, abdominal cramps and diarrhea [9,10].…”

Section: Introductionmentioning

confidence: 99%

Prevalence and Multiplex PCR for Enterotoxin Genes of Staphylococcus aureus Isolates from Subclinical Mastitis and Kareish Cheese

Mousa¹,

Abdeen²,

Hussein³

et al. 2017

J Infect Dis Preve Med

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Aim: Staphylococcus aureus was categorized as a contagious pathogen incriminated in subclinical mastitis as well as in dairy products. From public health view, this organism causing food poisoning outbreaks via contamination of food products with its toxins. These studies highlight the prevalence of staphylococcus aureus among subclinical mastitic cases as well as cheese samples and the dominant enterotoxigenic genes.Methodology: Examination of 100 samples (50 from subclinical mastitis, and 50 kareish cheese) from Sadat city, Menoufia province. Results and interpretation:Bacteriological culturing on selective and specific medium revealed that 26.7% and 30% in subclinical mastitis and kareish cheese respectively were due to S. aureus. Furthermore, multiplex PCR proved to be efficient technique for detection of different enterotoxins genes. The sea, seb and see genes were the most prevalent genes among the tested S. aureus isolates. Although, no detection of sec and sed genes were observed. Conclusion:It can be concluded that molecular characterization of S. aureus and its enterotoxins genes will be beneficial in designing control and preventive measures of S. aureus infection in human and animals.

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“…Both genes belong to the recently described enterotoxin gene cluster (egc) that harbours 5 to 6 genes (seg, sei, selm, seln, selo, and sometimes selu), which cluster on a staphylococcal pathogenicity island type I γSaβ [33,36,37], this cluster will be found without all of the egc components [33,[38][39][40]. Furthermore, many studies reported that some isolates contained selo gene with sed, selj and ser genes instead of the egc genes [40][41][42]; in fact, Thomas et al [42] suggested that this phenomenon is caused when a part of egc is exported or inserted in the chromosome of other S. aureus strains intermediated by insertion sequences.…”

Section: Discussionmentioning

confidence: 99%