scholarly journals Molecular Characteristics of Staphylococcus aureus From Food Samples and Food Poisoning Outbreaks in Shijiazhuang, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Guoping Lv ◽  
Ruiping Jiang ◽  
Han Zhang ◽  
Lei Wang ◽  
Lijie Li ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Potential Risk ◽  
Food Poisoning ◽  
Opportunistic Pathogen ◽  
Food Samples ◽  
Staphylococcal Enterotoxin ◽  
Molecular Characteristics ◽  
Resistant Gene ◽  
Human Infections ◽  
The Relationship

As an opportunistic pathogen worldwide, Staphylococcus aureus can cause food poisoning and human infections. This study investigated the sequence typing, the penicillin (blaZ) and methicillin (mec) resistance profiles of S. aureus from food samples and food poisoning outbreaks in Shijiazhuang City, and the staphylococcal enterotoxin (SE) types of the S. aureus isolates from food poisoning. A total of 138 foodborne S. aureus isolates were distributed into 8 clonal complexes (CCs) and 12 singletons. CC1, CC5, CC8, CC15, CC97, CC59, CC398, CC88, and CC7 were the predominant CCs of foodborne S. aureus isolates. Moreover, CC59, CC15, and CC5 were the most prevalent CCs in food poisoning outbreaks. SEE was the most commonly detected SE in food poisoning isolates. One hundred thirty-three S. aureus isolates harbored the penicillin-resistant gene blaZ, and nine isolates carried the mec gene. The present study further explained the relationship between S. aureus and foods and food poisoning and indicated the potential risk of S. aureus infection.

Determination of antibiotic resistance and enterotoxigenic potential of Staphylococcus aureus strains isolated from foods sold by street vendors in Gaborone, Botswana

2017 ◽  
Vol 6 (04) ◽  
pp. 5334 ◽  
Author(s):  
Daniel Loeto ◽  
Kabo Wale ◽  
Tidimalo Coetzee ◽  
Krishna B. Khare* ◽  
Thabang Carol Sigwele ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Food Poisoning ◽  
Food Samples ◽  
Latex Agglutination ◽  
Staphylococcal Enterotoxin ◽  
Penicillin G ◽  
Personal Hygiene ◽  
Street Vendors ◽  
Antibiotic Resistance Profile

Staphylococcus aureus is one of the causes of foodborne diseases worldwide. Staphylococcal food poisoning ensues after ingestion of contaminated food and results in symptoms of gastroenteritis such as vomiting, abdominal cramps and diarrhea. The present paper aims to isolate Staphylococcus aureus from foods sold by street vendors in Gaborone, Botswana, and to determine its enterotoxigenic potential and antibiotic resistance profile. One hundred eight food samples comprising starch, meat, salads and vegetables portions were collected from these vendors and tested for the presence of S. aureus. Identification of Staphylococcus aureus to the species level was performed using the Vitek 2 automated identification and susceptibility testing system (BioMerieux, Marcy-I’Etoile, France). Enterotoxins were detected by the Reversed Passive Latex Agglutination method (SET-RPLA). Results showed that 49 (45%) of the samples tested positive for Staphylococcus aureus. The organism was isolated at higher frequencies in vegetables and starchy foods (34.7%) than in meats (30.6%). These differences in isolation rates however, were not statistically significant (p> 0.05). Staphylococcus aureus isolates were found to be resistant to penicillin G (52.4%), tetracycline (38.1%), methicillin (26.2%) and vancomycin (11.9%). Four Staphylococcal enterotoxin types A-D, were detected among the isolates. Staphylococcal enterotoxin D was the most prevalent (52.9%), while enterotoxin C was produced by the least number of isolates (5.9%). Of note, five isolates simultaneously expressed two or more enterotoxin types in varying combinations. The present study underscores a potential risk of staphylococcal food poisoning and transmission of methicillin resistant S. aueus strains for consumers of street vended food products in Gaborone, Botswana especially in the absence of a quality assurance regulatory framework. As a mitigating factor, sensitization of street food vendors on the importance of food and personal hygiene is strongly recommended.

scholarly journals Molecular Detection of Staphylococcal Enterotoxins and mecA Genes Products in Selected Food Samples Collected from Different Areas in Khartoum State

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mohammed Yahya Ahmed ◽  
Hashim Abdalbagi Ali ◽  
Babbiker Mohammed Taher Gorish ◽  
Sara Omer Ali ◽  
Eman Saif Aldein Abdalrhim ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Meca Gene ◽  
Food Poisoning ◽  
Meat Products ◽  
Low Frequency ◽  
Raw Milk ◽  
Food Samples ◽  
Increased Risk ◽  
Enterotoxin B ◽  
Staphylococcus Aureus Enterotoxins

Staphylococcal food poisoning is an intoxication that results from the consumption of improperly prepared or stored foods containing sufficient amounts of one or more preformed S. aureus enterotoxins. Nowadays, many researchers worldwide noted an emergence of resistant strains such as Staphylococci particularly for the antibiotic methicillin. Therefore, this study was aimed to determine the existence of Staphylococcus aureus and its enterotoxins, mecA genes, in selected food samples. A total of 400 selected food samples were collected from different areas in Khartoum State. The selected foods included cheese, meat products, fish, and raw milk. One hundred samples from each type of food were cultivated, and the resultant growth yielded 137 (34.25%) S. aureus, 126 (31.5%) bacteria other than S. aureus, and 137 (34.25%) yielded no growth. Eighty-four of the 137 S. aureus isolates were randomly selected and tested for the presence of mecA and enterotoxin genes. The oxacillin sensitivity test showed that 15 (11%) of 137 S. aureus isolates were oxacillin resistant. The PCR assay showed that the mecA gene was detected in 15 of 84 (17%) S. aureus isolates. Simultaneously, only 2 (2.385%) out of 84 S. aureus isolates showed an enterotoxin B gene product. There was a relatively moderate prevalence of methicillin-resistant Staphylococcus aureus with very low frequency of enterotoxin B gene in different kinds of selected food samples collected from Khartoum State. These findings elucidate the increased risk on public in Khartoum being affected by Staphylococcal food poisoning upon consumption of dairy or meat products prepared in unhygienic conditions that could lead to intoxication by Staphylococcus aureus enterotoxins.

Characteristics of Enterotoxin H–Producing Staphylococcus aureus Isolated from Clinical Cases and Properties of the Enterotoxin Productivity

2008 ◽  
Vol 71 (9) ◽  
pp. 1855-1860 ◽  
Author(s):  
FUMIHIKO SAKAI ◽  
HIDESHI IHARA ◽  
KENJI AOYAMA ◽  
HIDEO IGARASHI ◽  
SHUICHI YANAHIRA ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Water Activity ◽  
Food Poisoning ◽  
Brain Heart Infusion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Late Exponential Phase ◽  
Epidemiological Characteristic ◽  
Predominant Type ◽  
High Prevalence ◽  
The Relationship

Staphylococcal enterotoxin H (SEH) is predicted to be involved in staphylococcal food poisoning. To characterize SEH-producing Staphylococcus aureus isolates from staphylococcal food poisoning cases in Japan, we investigated the relationship between SEH production and coagulase serotype, which is an epidemiological marker, and compared the properties of SEH production with those of staphylococcal enterotoxins A (SEA) and B (SEB). SEH production was determined by a newly developed sandwich enzyme-linked immunosorbent assay. Eighty-six (59.7%) of 144 isolates from staphylococcal food poisoning cases produced SEH. Seventy-one of the SEH-producing isolates simultaneously produced SEA, SEB, or both. All SEH-producing isolates belonged to coagulase type VII, which was the predominant type, representing 99 (68.8%) of 144 isolates. The amount of SEH produced in brain heart infusion was almost the same as the amount of SEA and approximately 10-fold lower than that of SEB. SEH and SEA were produced mainly during the late exponential phase of growth, whereas SEB was produced mostly during the stationary phase. The production levels of SEH and SEA were gradually affected by decreases in water activity, but the production of SEB was greatly reduced under conditions of low water activity. These findings indicate that SEH-producing S. aureus isolates are of high prevalence in staphylococcal food poisoning cases. Given the unique epidemiological characteristic of these isolates, SEH and SEA probably are responsible for food poisoning.

scholarly journals TSST-1, enterotoxin and bacteriocin-like substance production by Staphylococcus aureus isolated from foods

2013 ◽  
Vol 65 (5) ◽  
pp. 1537-1544 ◽  
Author(s):  
S.A. Carvalho ◽  
L.S. Carmo ◽  
E.F. Abreu ◽  
R.S. Dias ◽  
A.C.M. Apolônio ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bovine Milk ◽  
Food Poisoning ◽  
Brain Heart Infusion ◽  
Food Samples ◽  
Antagonistic Activity ◽  
Toxic Shock ◽  
Toxic Shock Syndrome Toxin ◽  
Reference Strains ◽  
Infusion Agar

The production of Toxic Shock Syndrome Toxin-1 (TSST-1), enterotoxins and bacteriocin-like substances was evaluated in 95 strains of Staphylococcus aureus recovered from raw bovine milk (n=31) and from food samples involved in staphylococcal food poisoning (n=64). Enterotoxigenicity tests with the membrane over agar associated to optimal sensibility plate assays were performed and showed that 96.77% of strains recovered from milk and 95.31% from food samples produced enterotoxins A, B, C, D or TSST-1. Reference strains S. epidermidis, Bacillus cereus, Listeria monocytogenes, Lactobacillus casei, Pseudomonas aeruginosa, S. aureus, Salmonella Typhimurium, Escherichia coli, Enterococcus faecalis and Bacteroides fragilis were used as indicator bacteria in the antagonistic assays, the first five being sensitive to antagonistic substances. Brain heart infusion agar, in pH values ranging from 5.0 to 7.0 in aerobic atmosphere showed to be the optimum condition for antagonistic activity as evaluated with the best producer strains against the most sensitive indicator bacterium, L. monocytogenes. Sensitivity to enzymes confirmed the proteinaceous nature of these substances. Neither bacteriophage activity nor fatty acids were detected and the antagonistic activity was not due to residual chloroform. Results did not establish a positive correlation between the bacteriocinogenic profile and toxigenicity in the tested S. aureus strains.

An Immunomagnetic PCR Signal Amplification Assay for Sensitive Detection of Staphylococcus aureus Enterotoxins in Foods

2009 ◽  
Vol 72 (12) ◽  
pp. 2538-2546 ◽  
Author(s):  
LEENALITHA PANNEERSEELAN ◽  
PETER M. MURIANA
Keyword(s):  
Staphylococcus Aureus ◽  
Signal Amplification ◽  
Magnetic Beads ◽  
Food Poisoning ◽  
High Sensitivity ◽  
The United States ◽  
Food Samples ◽  
Dna Oligonucleotides ◽  
Amplification Assay ◽  
Covalently Linked

Enterotoxigenic strains of Staphylococcus aureus produce a variety of heat-stable staphylococcal enterotoxins (SEs) that are a prevalent cause of food poisoning in the United States and other countries. Many immunological and biochemical assays often work well in buffer systems but are hindered when tested in the complex chemical environment of foods. To overcome these biases and improve the limits of detection, we implemented an immunomagnetic PCR signal amplification assay (iPCR-SA) for recovery and detection of SEA and SEB in foods. Anti-SEA or anti-SEB primary antibodies were coated onto COOH-modified magnetic beads using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide reagent. Secondary antibodies were covalently linked to amino-modified reporter DNA oligonucleotides (563 bp) via the linker molecule succinimidyl-4[N-maleimidomethyl]-cyclohexane-1-carboxylate. An internal 159-bp portion of the reporter DNA retained by the captured toxin molecule was then amplified by real-time PCR. A semiautomated Bead Retriever proved extremely helpful in both the application of the conjugation chemistries and required washes and the recovery and washing of bead-conjugated toxin from tested food samples. The procedure was simple, and analyses were completed in 5 to 6 h. The assay was sufficiently robust that we were able to detect SEA and SEB in tryptic soy broth, milk, lemon cream pie, tuna salad, deli turkey, and ground turkey at levels as low as 7.5 fg/ml. SE was still detected at high sensitivity after heating in food samples for typical pasteurization or cooking regimens. Sensitivity was diminished only when samples were subjected to extreme heating.

scholarly journals Serological detection of enterotoxin in foods implicated in staphylococcal food poisoning

1972 ◽  
Vol 70 (4) ◽  
pp. 755-762 ◽  
Author(s):  
R. J. Gilbert ◽  
Antonnette A. Wieneke ◽  
Janice Lanser ◽  
Magda Šimkovičová
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Food Samples ◽  
Serological Detection

SUMMARYTwo methods are described for the extraction of enterotoxin from foods incriminated in incidents of staphylococcal food poisoning. Enterotoxin was detected serologically in 12 of 24 food samples from 20 separate incidents: eight samples contained enterotoxin A, three contained D and one both A and B. The amount of enterotoxin in nine foods, based on 100 % recovery, varied from 0·02 to 0·09 μg./g.Data are also given on the numbers ofStaphylococcus aureusisolated from samples of food from 39 food poisoning incidents. Colony counts varied between 7·5 × 105and 9 × 109/g. with a median value of 7 × 107/g.

Atypical Toxigenic Staphylococcus and Non-Staphylococcus aureus Species on the Horizon? An Update†

1996 ◽  
Vol 59 (10) ◽  
pp. 1123-1126 ◽  
Author(s):  
REGINALD W. BENNETT
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Staphylococcal Enterotoxin ◽  
Foodborne Illness ◽  
Coagulase Negative Staphylococci ◽  
Rapid Methods ◽  
Staphylococcal Species ◽  
Enterotoxin Production

Staphylococcal food poisoning is a commonly reported illness caused by the ingestion of preformed staphylococcal enterotoxin in foods, With some exceptions, enterotoxin production is associated with coagulase-positive rather than coagulase-negative staphylococci. Of the coagulase-positive staphylococcal species, S. aureus was historically thought to be exclusively implicated in human foodborne illness. More recently, however, other coagulase-positive and some coagulase-negative staphylococcal species have been associated with foodborne intoxication, Coagulase activity has been used to indicate pathogenicity of a foodborne isolate, and thermostable nuclease is being suggested as a more reliable indictor of enterotoxigenicity. Evidence suggests that the metabolic expressions that are the bases of the tests may not be reliable indicators of pathogenicity. A more useful approach to determine the pathogenicity of a Staphylococcus species is to test directly for enterotoxigenicity with one of the new rapid methods. None of the conventional ancillary identification tests has been conclusively associated with enterotoxin synthesis. Furthermore, evidence exists that enterotoxin production is a characteristic of several species in the genus Staphylococcus.

Staphylococcus aureus Isolates from Irish Domestic Refrigerators Possess Novel Enterotoxin and Enterotoxin-like Genes and Are Clonal in Nature

2006 ◽  
Vol 69 (3) ◽  
pp. 508-515 ◽  
Author(s):  
DAVIDA S. SMYTH ◽  
JEAN KENNEDY ◽  
JANE TWOHIG ◽  
HELEN MIAJLOVIĆ ◽  
DECLAN BOLTON ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Broiler Chickens ◽  
Random Amplified Polymorphic Dna ◽  
Protein A ◽  
Food Poisoning ◽  
Staphylococcal Enterotoxin ◽  
Penicillin G ◽  
Animal Origin ◽  
Pcr Analysis ◽  
Potential Reservoir

A previous study carried out by the National Food Centre in Dublin on bacterial contamination of Irish domestic refrigeration systems revealed that 41% were contaminated with Staphylococcus aureus. One hundred fifty-seven S. aureus isolates were screened by multiplex PCR analysis for the presence of 15 staphylococcal enterotoxin and enterotoxin-like genes (seasee, seg-sei, selj-selo, and selq) and the toxic shock toxin superantigen tst gene. Of the refrigerator isolates, 64.3% possessed more than one staphylococcal enterotoxin or staphylococcal enterotoxin–like gene. All bar one of the 101 staphylococcal enterotoxin or staphylococcal enterotoxin–like gene-positive strains possessed the egc locus bearing the seg, sei, selm, seln, and selo genes. Twelve random amplified polymorphic DNA (RAPD) types accounted for 119 (75.8%) of the strains, two of these types accounting for 25 (RAPD type 1, 15.9%) and 52 (RAPD type 5, 33.1%), respectively. All of the RAPD type 5 isolates possessed the egc gene cluster only. The RAPD type 5 amplicon profile was identical to that of S. aureus isolates associated with osteomyelitis in broiler chickens in Northern Ireland that also possessed the egc locus only. However, the RAPD type 5 domestic refrigerator and chicken isolates differed in penicillin G sensitivity, production of Protein A and staphylokinase, and crystal violet agar growth type. These findings highlight that the average Irish household refrigerator harbors potential enterotoxin-producing S. aureus that may or may not be of animal origin and, accordingly, is a potential reservoir for staphylococcal food poisoning.

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