• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.806-810
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• 1999

A multiplex-polymerase chain reaction (PCR) assay was used to detect staphylococcal enterotoxin production by 12 strains of Staphylococcus aureus isolated from clinical specimens. To evaluate the efficacy and/or sensitivity of this method, the results were compared to those obtained with the reversed passive latex agglutination kit (SET-RPLA, Denka Seiken, Japan). Of 10 strains positive by PCR were positive by RPLA but two strains, representing high sensitivity of the former method. Enterotoxin B was the most prevalent by the two methods. The kappa index between the two methods was 0.826, indicating a higher agreement and fully reliable for use. These results would suggest that sensitive, inexpensive, and relatively rapid multiplex-PCR technique may be an effective means for the detection of staphylococcal enterotoxin genes as an alternative to traditional methods such as kits or immunological methods, which depend upon the amount of enterotoxin produced.

• Korean Journal of Veterinary Service
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• v.33 no.3
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• pp.255-261
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• 2010

At the present study, it was aimed to explore the states of antimicrobial resistant Staphylococcus aureus isolates from 320 pigs and cattle carcass (160 pigs and 160 cattle) slaughtered in Busan province from March 2008 to November 2009. Among 320 samples, 26 of Staphylococcus aureus were isolated from pigs (10.6%) and cattle (5.6%). In antimicrobial susceptibility test, all of the isolates were demonstrated susceptibility to oxacillin, cefoxitin, cephalothin, vancomycin, rifampin and linezolid. But the isolates were showed resistance other antibiotics in order of penicillin (92.3%), gentamicin (76.9%), tetracycline (69.2%), erythromycin (65.4%), and clindamycin (61.5%). In case of enterotoxin production, 7.7% of 2 strains produced enterotoxin A.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.549-557
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• 2019

Staphylococcal enterotoxin is a very common cause of food poisoning. Conventional detection methods for the toxin including enzyme-linked immunosorbent assays (ELISAs), chemiluminescence (ECL), and polymerase chain reaction (PCR) assays require a lot of time, efforts, and expert technicians. Lateral flow strip kits have shown great potential for the rapid detection of foodborne pathogens. The lateral flow strip kit is widely used in clinical settings because it is easy to use, fast, and cost effective. A typical lateral flow strip kit uses colloidal gold to generate a visual signal. However, the lateral flow strip kit based on colloidal gold has limited sensitivity to fulfill food safety regulation requirements. This study was performed to develop a rapid test kit for pathogenic staphylococcal enterotoxin B (SEB) in food samples. The rapid detection kit was fabricated based on a nitrocellulose lateral-flow strip. Cellulose nano beads and SEB antibodies were used as the tag and receptor, respectively, to improve the detection performance. Manually spotted SEB antibody and anti-rabbit antibody on the surface of the nitrocellulose membrane were used as test and control spots, respectively. The feasibility of the rapid test kit to detect SEB in samples was evaluated. The sensitivity of the kit was 10 ng/mL SEB spiked in PBS. Additionally, the rapid test kit could detect 1 ng/mL of SEB in chicken meat extract.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.159-167
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• 2001

Staphylocorccus aureus is gram positive, facultatively anaerobic, non-sporulative coccus, and positive for coagulase and DNase. The food-poisoning outbreak of Staphylococcus aureus increases in the world, and third occurrence happened in our country. Of 105 isolates (25.4%) obtained 413 focal samples of food-poisoning suspicious patients. In those cases, the enterotoxins were detected from a total of 45 isolates (42.9%), 9 isolates(20.0%) were A type, 33 isolates (73.3%) were H types, 2 isolates (4.4%) were G type and 1 isolate was a I type enterotoxin. Among the isolates possessing staphylococcal enterotoxins, 29 isolates had H type only(64.4%), 5 isolates had A type only and 4 isolates had both A and H type. Two isolates had G type only and 1 isolate had I type only. In the antibiotic susceptibility, 48 isolates (46%) had at least one antibiotic resistance among 105 isolates, 34 isolates (70.8%) were resistant to penicillin. 1 isolate (2.1%) to ampicillin, 3 isolates (6.3%) to erythromycin and kanamycin. Seven were resistant to more than two antibiotics and especially 1 isolate was resistant to penicillin-ampicillin-nitrofurantoin.

• Biomedical Science Letters
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• v.7 no.2
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• pp.85-89
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• 2001

Many Staphylococcus aureus strains produce enterotoxins causing food poisoning. Staphylococcal enterotoxins are classified by serological criteria into five major groups - subtype A to E. It is difficult, time-consuming, and expensive to detect staphylococcal enterotoxins in the clinical laboratory. In this study, we fried to detect the enterotoxin genes of Staphylococcus aureus strains isolated from clinical specimens and Kimbap - rice rolled in a sheet of laver - using multiplex PCR technique. A total of 77 strains of Staphylococcus aureus from clinical specimens and 78 strains from Kimbap were isolated. Among clinical isolates of S. aureus, 60 strains (78.0%) were identified as producing enterotoxins. A total offs strains (91.6%) in the 60 staphylococcal enterotoxin producing strains were enterotoxin subtype C. In case of kimbap: 43 (55.1%) strains were detected to produce enterotoxins and 39 (90.6%) enterotoxin producing strains were subtype A.

• Journal of Food Hygiene and Safety
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• v.3 no.2
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• pp.75-81
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• 1988

Various methods such as lel-mtration on Sephadex G-SO, 75, 100 Sephacry, and Ultro gel, and lon-exchanle chromatoaraphy on Amberilte and carboxymethyl (CM)-cellulose, and Fast Protein liquid Chromatolraphy (FPLC) were applied for the purification of enterotoxin B from Staphylococcus aureus ATCC 14458 and compared one another. lon-exchanle chromatography on Amberllte resin was good enough to remove non-entrotoxln materials in culture, convlnient to use and fast although tbe purity was less tban 70%. However, CM-cellulose showed to be better purity and yield tban those of Amberilte resin. The yields of these two resins for ion-exchange cbromatograpby were about 70% and 75%, respectively. When the gel-filtration methods on Sepbadex G-50, 75, 100, Sepbacryl, and Ultro lei were applied, the purities were about 90%. FPLC was found to be tbe most efficient metbod in terms of purity (96%) and speed. For the purification of sample with large volume, particularly, tbe combined metbod, gel-mtration after Amberlite can be also used efficiently. Tbe purified toxin was found to be identical to type B enterotoxin used for reference standard by Oucbterlony immunodiffusion test.

• The Journal of the Korean Society for Microbiology
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• v.18 no.1
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• pp.53-58
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• 1983

Enterotoxigenic E. coli is one of causative agents of the infantile diarrhea and traveler's diarrhea. A modified infant mouse assay(IMA) was developed for the detection of heat stable enterotoxin (ST) of E. coli isolated from diarrheal and control infants and assay system was established with using enterotoxin producing reference strains. The supernatant of the 24 hour-shaking culture of E. coli in Casamino Acid Yeast Extract Salt Broth(CYES-2) was ingested orally into the 2-4 day old ICR mice. After the mice were kept at $25^{\circ}C$ for 4 hours, they were sacrificed and the gut weight body weight ratio(GW/BW) was taken as the index of fluid accumulation induced by heat stable enterotoxin of E. coli. The results obtained were as follows; 1. The GW/BW responses of IMA tested with enterotoxin reference strains of E. coli(E. coli O148H28:$ST^+LT^+$, E. coli $O78H^-:ST^+LT^+$, E. coli O15H11:$ST^-LT^+$, E. coli O1H7:$ST^-LT^-$) appeared ta be ST dose-dependent, and not LT-dependent. From the dose-response curve, $25{\mu}l$ of culture supernatant was determined as test amount of the IMA. 2. Frequency distribution of IMA result from 643 strain of E. coli showed normal distribution at low GW/BW ratio and dispersed pattern at high GW/BW ratio. The GW/BW ratios of $0.056{\pm}0.004(mean{\pm}SD)$ of normal distribution which distributed from 0.044 to 0.068(P<0.01) was considered as ST negative. Thus the GW/BW ratio above 0.069 could be regarded as ST positive.

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.59-65
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• 1988

This paper deals with the 0 groups of citrate utilizing variants of Escherichia coli ($Cit^+$ E. coli) isolated from cattle, the production of colicin, hemolysin, K99 antigen, heat stable enterotoxin, and the isolation of plasmid DNA. Among 42 $Cit^+$ E. coli, 12 strains were 020, 9 strains 08, 5 strains 045, 3 strains 0115, 1 strain 064, 1 strain 0139 and remaining strains(11) were untypable. Thirty-nine(81.3%) out of 48 $Cit^+$ E. coli were produced colicin and 13(27.0%) were produced hemolysin. Of 12 $Cit^+$ E. coli bearing K99 antigen, 6(50.0%) were produced heat stable enterotoxin. In gel electrophoresis for the isolation of plasmid DNA, the number of plasmids varied from 1 to 7 in 10 $Cit^+$ E. coli. It's molecular weight ranged from 2 to 50 Mdalton, and 50 Mdalton plasmid was commonly existed in all strains.

• Applied Biological Chemistry
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• v.51 no.4
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• pp.263-268
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• 2008

Seventy-one Bacillus cereus strains (12 references and 59 food isolates) were analyzed for the occurrence of five different enterotoxin genes (nheABC, hblCDA, entFM, cytK, and bceT) and one emetic toxin cereulide synthetase gene (ces) by PCR (polymerase chain reaction). PCR analysis revealed eight toxigenic patterns in all B. cereus strains tested; they all carried both entFM and nheABC. The presence of hblCDA, cytK, and bceT varied according to the enterotoxin-producing strains, among which hblCDA was the least frequently detected in the food-isolated strains. Only five B. cereus strains harbored ces, associated with the emetic type of food poisoning; however, these strains were devoid of hblCDA, cytK, and bceT.

• Korean Journal of Microbiology
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• v.16 no.4
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• pp.161-169
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• 1978

Escherichiae-like organisms were isolated from rectal specimens of 56 children who were either in preschool age or in elementary school. The isolated strains were subjected to tests to screen enteropathogens producing heat-labile enterotoxin and susceptibility test to various antibiotics by disc diffusion method on agar plates. Production of heat-labile enterotoxin by the strains was assyed in the sensitive and reproducible cultured adrenal tumor cell system. The assay was sterodogenesis of the cell in the presence of heat-labile enterotoxin. Among 56 strains, gave positive reaction in the test of toxin production. This meant that about 10% of the children population objected to the study harbored the toxigenic strain of enteropathogenes. Some of these toxigenic strains were resistant to the antibiotics employed in the test. This study suggested that considerable population in Korea may harbor entertoxigenic E. coli as a part of intestinal normal flora. The toxigenic strains which are resistant to antibiotics may bring issue of public health in the future.