scholarly journals Occurrence, enterotoxin production and antimicrobic susceptibility of Staphylococcus aureus isolates from domestic cheeses in the Dubrovnik area

2021 ◽  
Vol 53 (2) ◽  
Author(s):  
Ivana Ljevaković-Musladin ◽  
Marina Vodnica-Martucci ◽  
Marija Krilanović ◽  
Lidija Kozačinski
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Epidemiological Data ◽  
Raw Milk ◽  
Latex Agglutination ◽  
Staphylococcal Enterotoxin ◽  
Contamination Level ◽  
Enterotoxin Production ◽  
Wide Range ◽  
High Level

Staphylococcus aureus is a well-known op¬portunistic pathogen that causes a wide range of acute and chronic diseases in both humans and animals. Staphylococcal food poisoning is just one of many diseases caused by this bacterium. The causative agents are entero¬toxins produced by enterotoxigenic strains of S. aureus during its growth in favourable conditions in food. Epidemiological data show that S. aureus is often found in raw milk cheeses and accordingly, cheeses are often implicated in food poisoning outbreaks. Since there are no data on the nature of S. aureus isolated from cheese produced in Croatia, the aim of this study was to determine the occur¬rence, enterotoxin production capability and antimicrobic susceptibility of S. aureus iso¬lates from domestic cheeses produced in the Dubrovnik area. A total of 30 cheese samples were analysed, and 18 samples (60%) were highly contaminated with S. aureus strains. The contamination level ranged from 3.94 to 6.26 log10 cfu/g. Such a high level of contami¬nation was supported by an inappropriate temperature regime above 8°C during market sale. Although highly contaminated, staphy¬lococcal enterotoxins were not detected in any of the cheese samples. A total of 180 coagu¬lase-positive isolates were collected from 18 cheese samples, 175 of which were confirmed as S. aureus by the latex agglutination test. En¬terotoxin production was detected in 35 iso¬lates (20%), and of these 32 isolates produced staphylococcal enterotoxin C. The other three isolates presumably produced enterotoxin E. Antibiotic resistance was detected in 1.1% of isolates and only to mupirocin. However, a full comprehensive conclusion on the nature of S. aureus isolates cannot be achieved with¬out determining its genotype characteristics for the presence of staphylococcal enterotoxin genes and molecular typing, to determine the origin of the isolates.

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.

Comparison of Antibiogram, Staphylococcal Enterotoxin Productivity, and Coagulase Genotypes among Staphylococcus aureus Isolated from Animal and Vegetable Sources in Korea

2007 ◽  
Vol 70 (11) ◽  
pp. 2541-2548 ◽  
Author(s):  
JIN SAN MOON ◽  
AE RI LEE ◽  
SEUNG HYEUP JAW ◽  
HYUN MI KANG ◽  
YI SEOK JOO ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Tetracycline Resistance ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin ◽  
Food Sources ◽  
Polymorphism Analysis ◽  
Antibiotic Resistant ◽  
Raw Meat ◽  
Mastitic Milk

Staphylococcal food poisoning is caused by enterotoxin-producing Staphylococcus aureus. We investigated the prevalence of such organisms in samples of bovine mastitic milk (n = 714), raw meat (n = 139), and vegetables (n = 616). We determined the degrees of relatedness of isolates as indicated by antibiogram, staphylococcal enterotoxin (SE) productivity, and coagulase gene restriction fragment length polymorphism analysis. We examined 297 S. aureus isolates and found SE production in 57 (31.8%), 4 (7.8%), and 49 (73.1%) isolates from raw milk, raw meat, and vegetables, respectively. A high proportion of the isolates obtained from milk produced more than two types of toxins (mainly SEA, SEB, and/or SEC), whereas isolates from raw meat and vegetables primarily produced SEA alone. Most isolates were sensitive to cephalothin (97.6%), gentamicin (80.8%), erythromycin (79.5%), and tetracycline (72.7%), but were resistant to penicillin (90.2%) and ampicillin (88.9%). The proportion of antibiotic-resistant isolates differed according the source of the bacteria; the milk and vegetable isolates were more resistant to penicillin and ampicillin than were the meat isolates (P < 0.05), whereas tetracycline resistance was limited to the milk and vegetables isolates. The coagulase genotypes (I to XII) varied with the source of the organism, and only a few genotypes prevailed in each source: II (42.4%) and IV (24%) types in isolates from milk, IX (35.3%) and XI (45%) from raw meat, and III (40.3%) and XII (32.8%) from vegetables. These findings suggest that remarkable differences exist in antibiogram, SE productivity, and coagulase genotypes, resulting in limited clonal transmission of S. aureus into various food sources. As enterotoxin production only occurs when S. aureus grows to high numbers, staphylococcal food poisoning can be prevented by proper refrigeration.

Characterization of Staphylococcus aureus Strains Isolated from Raw Milk Utilized in Small-Scale Artisan Cheese Production

2011 ◽  
Vol 74 (8) ◽  
pp. 1353-1358 ◽  
Author(s):  
DENNIS J. D'AMICO ◽  
CATHERINE W. DONNELLY
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Phenotypic Diversity ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin ◽  
Small Scale ◽  
Enterotoxin Production ◽  
Type C ◽  
Cheese Production

Staphylococcus aureus is an important agent of bacterial mastitis in milking animals and of foodborne intoxication in humans. The purpose of this study was to examine the genetic and phenotypic diversity, enterotoxigenicity, and antimicrobial resistance of S. aureus strains isolated from raw milk used for the production of artisan cheese in Vermont. Cross-tabulations revealed that the 16 ribotypes identified among the 90 milk isolates examined were typically associated with a specific animal species and that more than half of these ribotypes were unique to individual farms. In general, specific EcoRI ribotypes were commonly associated with specific phenotypical characteristics, including staphylococcal enterotoxin production or the lack thereof. Limited antimicrobial resistance was observed among the isolates, with resistance to ampicillin (12.51%) or penicillin (17.04%) most common. Two isolates of the same ribotype obtained from the same farm were resistant to oxacillin with 2% NaCl. More than half (52.22%) of isolates produced toxin, and 31 of the 32 isolates solely produced staphylococcal enterotoxin type C. Although these data demonstrate that S. aureus strains found in raw milk intended for artisan cheese manufacture are capable of enterotoxin production, staphylococcal enterotoxin C is not typically linked to foodborne illness. Because S. aureus is a common contaminant of cheese, an understanding of the ecology of this pathogen and of the antimicrobial susceptibility and toxigenicity of various strains will ultimately contribute to the development of control practices needed to enhance the safety of artisan and farmstead cheese production.

Staphylococcal Enterotoxin A Gene–Carrying Staphylococcus aureus Isolated from Foods and Its Control by Crude Alkaloid from Papaya Leaves

2014 ◽  
Vol 77 (11) ◽  
pp. 1992-1997 ◽  
Author(s):  
LITA HANDAYANI ◽  
DIDAH NUR FARIDAH ◽  
HARSI D. KUSUMANINGRUM
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Dry Weight ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Assisted Extraction ◽  
Ultrasonic Assisted ◽  
Broth Macrodilution ◽  
Ultrasonic Assisted Extraction

Staphylococcus aureus is a known pathogen causing intoxication by producing enterotoxins in food. Staphylococcal enterotoxin A is one of the enterotoxins commonly implicated in staphylococcal food poisoning. The ability of crude alkaloid extract from papaya leaves to inhibit the growth of S. aureus and staphylococcal enterotoxin A synthesis was investigated. Staphylococcal enterotoxin A gene–carrying S. aureus was isolated from raw milk and ready-to-eat foods. Crude alkaloid was extracted from ground, dried papaya leaves using ultrasonic-assisted extraction, and a MIC of the alkaloid was determined by the broth macrodilution method. Furthermore, S. aureus isolate was exposed to the crude alkaloid extract at one- and twofold MIC, and the expression of sea was subsequently analyzed using a quantitative reverse transcription real-time PCR. Ten isolates of S. aureus were obtained, and nine of those isolates were sea carriers. The yield of crude alkaloid extract was 0.48 to 1.82% per dry weight of papaya leaves. A MIC of crude alkaloid to S. aureus was 0.25 mg/ml. After exposure to the alkaloid at 0.25 and 0.5 mg/ml for 2 h, a significant increase in cycle threshold values of sea was observed. The sea was expressed 29 and 41 times less when S. aureus was exposed to crude alkaloid at one- and twofold MIC, respectively. This study revealed that crude alkaloid of papaya leaves could control staphylococcal enterotoxin A gene–carrying S. aureus by suppressing the expression of sea, in addition to the ability to inhibit the growth of S. aureus. The expression of sea was successfully quantified.

Occurrence of Enterotoxic Staphylococcus aureus in Raw Milk from Yaks and Cattle in Mongolia

2007 ◽  
Vol 70 (7) ◽  
pp. 1726-1729 ◽  
Author(s):  
URANCHIMEG TSEGMED ◽  
GIOVANNI NORMANNO ◽  
MARIT PRINGLE ◽  
KAREL KROVACEK
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Food Poisoning ◽  
Raw Milk ◽  
Latex Agglutination ◽  
Animal Origin ◽  
Foodborne Illnesses ◽  
First Report ◽  
Milk Samples ◽  
Milk And Dairy Products

Staphylococcal food poisoning is considered one of the leading foodborne illnesses in humans worldwide and is associated with contaminated foods of animal origin, such as milk and dairy products. In this study, we investigated the occurrence of staphylococci and the enterotoxigenic properties of Staphylococcus aureus isolated from raw milk from yaks (Bos mutus) and cattle in Mongolia. Staphylococci were isolated from 72 (74%) of the 97 raw milk samples. Of the samples containing staphylococci, 69% (50 of 72) were from yaks and 30.5% (22 of 72) were from cattle. S. aureus was detected in 10% of yak (7 of 72) and 21% of cattle (15 of 72) milk samples. Staphylococcal enterotoxin C was detected in 23% (5 of 22) of the S. aureus strains investigated, based on the reverse passive latex agglutination technique. Three of the five enterotoxigenic strains were from yaks and two were from cattle. None of the S. aureus strains tested produced staphylococcal enterotoxins A, B, or D. To our knowledge, this is the first report of the occurrence of staphylococci and enterotoxigenic S. aureus in milk from yaks and cattle in Mongolia.

scholarly journals Screening of hybridoma cell lines secreting monoclonal antibodies specific for staphylococcal enterotoxin B (SEB) derived from Staphylococcus aureus

2016 ◽  
Vol 14 (1) ◽  
pp. 23-28
Author(s):  
Nghiêm Ngọc Minh ◽  
Nguyễn Thị Hoài Thu ◽  
Phạm Thùy Linh ◽  
Thân Đức Dương ◽  
Vũ Thị Thu Hằng ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Monoclonal Antibodies ◽  
B Lymphocytes ◽  
Food Poisoning ◽  
Gastrointestinal Diseases ◽  
Recombinant Antigen ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin B ◽  
Enterotoxin B ◽  
High Level

Staphylococcus aureus (S. aureus) produces 11 types of toxins and more than 20 different Staphylococcal enterotoxins (SEs), including SEA to SEE, SEG to SER and SEU. Among them, enterotoxin type B (Staphylococcal enterotoxin B - SEB) is quite heat stable and causes gastrointestinal diseases in food poisoning. The symptoms of SEB intoxication begin with the onset of sudden fever, about 40oC to 41oC, chills, headache, muscle aches and dry cough. Some patients feel shortness of breath and chest pain. Although SEB is not considered lethal, high level of exposure can lead to shock and death. Therefore, a nontoxic SEB recombinant antigen was produced to immunize mice to create B lymphocytes. Myeloma cells were fused with the B lymphocytes to generate  hybridoma lines. The screening of monoclonal antibodies for the SEB antigen was determined by ELISA and Western blot tests. This study demonstrates that an SEB recombinant antigen can immunize a response against SEB in BALB/c mice. The production of monoclonal antibodies will be used to make a rapid detection strip for SEB based on immunochromatography.

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.

Phylogeny Characterization of Seb Gene Encoding Enterotoxins in Staphylococcus aureus Isolated from Raw Milk and Cheese

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Fatima N. Aziz ◽  
Laith Abdul Hassan Mohammed-Jawad
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin B ◽  
Human Pathogen ◽  
Conventional Pcr ◽  
Biochemical Tests ◽  
Specific Primers ◽  
Gene Encoding

Food poisoning due to the bacteria is a big global problem in economically and human's health. This problem refers to an illness which is due to infection or the toxin exists in nature and the food that use. Milk is considered a nutritious food because it contains proteins and vitamins. The aim of this study is to detect and phylogeny characterization of staphylococcal enterotoxin B gene (Seb). A total of 200 milk and cheese samples were screened. One hundred ten isolates of Staphylococcus aureus pre-confirmed using selective and differential media with biochemical tests. Genomic DNA was extracted from the isolates and the SEB gene detects using conventional PCR with specific primers. Three staphylococcus aureus isolates were found to be positive for Seb gene using PCR and confirmed by sequencing. Sequence homology showed variety range of identity starting from (100% to 38%). Phylogenetic tree analyses show that samples (6 and 5) are correlated with S. epidermidis. This study discovered that isolates (A6-RLQ and A5-RLQ) are significantly clustered in a group with non- human pathogen Staphylococcus agnetis.

scholarly journals Prevalence of Chlorhexidine-Resistant Methicillin-Resistant Staphylococcus aureus following Prolonged Exposure

2014 ◽  
Vol 58 (8) ◽  
pp. 4404-4410 ◽  
Author(s):  
Carey D. Schlett ◽  
Eugene V. Millar ◽  
Katrina B. Crawford ◽  
Tianyuan Cui ◽  
Jeffrey B. Lanier ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Analysis ◽  
Prolonged Exposure ◽  
Controlled Trial ◽  
Epidemiological Data ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mupirocin Resistance ◽  
High Level ◽  
Study Participants

ABSTRACTChlorhexidine has been increasingly utilized in outpatient settings to control methicillin-resistantStaphylococcus aureus(MRSA) outbreaks and as a component of programs for MRSA decolonization and prevention of skin and soft-tissue infections (SSTIs). The objective of this study was to determine the prevalence of chlorhexidine resistance in clinical and colonizing MRSA isolates obtained in the context of a community-based cluster-randomized controlled trial for SSTI prevention, during which 10,030 soldiers were issued chlorhexidine for body washing. We obtained epidemiological data on study participants and performed molecular analysis of MRSA isolates, including PCR assays for determinants of chlorhexidine resistance and high-level mupirocin resistance and pulsed-field gel electrophoresis (PFGE). During the study period, May 2010 to January 2012, we identified 720 MRSA isolates, of which 615 (85.4%) were available for molecular analysis, i.e., 341 clinical and 274 colonizing isolates. Overall, only 10 (1.6%) of 615 isolates were chlorhexidine resistant, including three from the chlorhexidine group and seven from nonchlorhexidine groups (P> 0.99). Five (1.5%) of the 341 clinical isolates and five (1.8%) of the 274 colonizing isolates harbored chlorhexidine resistance genes, and four (40%) of the 10 possessed genetic determinants for mupirocin resistance. All chlorhexidine-resistant isolates were USA300. The overall prevalence of chlorhexidine resistance in MRSA isolates obtained from our study participants was low. We found no association between extended chlorhexidine use and the prevalence of chlorhexidine-resistant MRSA isolates; however, continued surveillance is warranted, as this agent continues to be utilized for infection control and prevention efforts.

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