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.

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.

scholarly journals The use of a sandwich ELISA for the detection of staphylococcal enterotoxin A in foods from outbreaks of food poisoning

1985 ◽  
Vol 95 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Antonnette A. Wieneke ◽  
R. J. Gilbert
Keyword(s):  
Staphylococcus Aureus ◽  
Solid Phase ◽  
Sandwich Elisa ◽  
Extraction Procedure ◽  
Food Poisoning ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Staph Aureus ◽  
Concentration Step ◽  
Simple Extraction

SUMMARYFoods from outbreaks of food poisoning were examined for the presence of staphylococcal enterotoxin A (SEA) by a sandwich ELISA using microtitre trays as the solid phase and SEA antibodies raised in sheep.The presence of SEA was confirmed by neutralization tests. The toxin was detected in 12 of 15 foods from separate outbreaks of staphylococcal food poisoning; all 15 foods contained a strain ofStaphylococcus aureuswhich produced SEA. For most foods a simple extraction procedure without a concentration step was sufficient to detect the toxin. The method was semi-quantitative and recoveries of SEA added to control foods varied from 30 to 80%. The foods from outbreaks contained between 1 and 10 μg of SEA/100 g. SEA was not found in foods from 21 outbreaks in which an SEA-producing strain ofStaph. aureuswas not isolated.

Quantitative Microbial Risk Assessment for Staphylococcus aureus and Staphylococcus Enterotoxin A in Raw Milk

2009 ◽  
Vol 72 (8) ◽  
pp. 1641-1653 ◽  
Author(s):  
JOELLE C. HEIDINGER ◽  
CARL K. WINTER ◽  
JAMES S. CULLOR
Keyword(s):  
Risk Assessment ◽  
Staphylococcus Aureus ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin ◽  
Milk Consumption ◽  
Quantitative Microbial Risk Assessment ◽  
Staphylococcal Enterotoxin A ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Consumer Risk

A quantitative microbial risk assessment was constructed to determine consumer risk from Staphylococcus aureus and staphylococcal enterotoxin in raw milk. A Monte Carlo simulation model was developed to assess the risk from raw milk consumption using data on levels of S. aureus in milk collected by the University of California–Davis Dairy Food Safety Laboratory from 2,336 California dairies from 2005 to 2008 and using U.S. milk consumption data from the National Health and Nutrition Examination Survey of 2003 and 2004. Four modules were constructed to simulate pathogen growth and staphylococcal enterotoxin A production scenarios to quantify consumer risk levels under various time and temperature storage conditions. The three growth modules predicted that S. aureus levels could surpass the 105 CFU/ml level of concern at the 99.9th or 99.99th percentile of servings and therefore may represent a potential consumer risk. Results obtained from the staphylococcal enterotoxin A production module predicted that exposure at the 99.99th percentile could represent a dose capable of eliciting staphylococcal enterotoxin intoxication in all consumer age groups. This study illustrates the utility of quantitative microbial risk assessments for identifying potential food safety issues.

scholarly journals Optimization of Sonotrode Ultrasonic-Assisted Extraction of Proanthocyanidins from Brewers’ Spent Grains

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 282 ◽  
Author(s):  
Beatriz Martín-García ◽  
Federica Pasini ◽  
Vito Verardo ◽  
Elixabet Díaz-de-Cerio ◽  
Urszula Tylewicz ◽  
...  
Keyword(s):  
Dry Weight ◽  
Ultrasound Assisted Extraction ◽  
Established Method ◽  
Qualitative And Quantitative ◽  
Assisted Extraction ◽  
Acetone Water ◽  
Spent Grains ◽  
Ultrasonic Assisted ◽  
Quantitative Analyses ◽  
Ultrasonic Assisted Extraction

Brewing spent grains (BSGs) are the main by-product from breweries and they are rich of proanthocyanidins, among other phenolic compounds. However, literature on these compounds in BSGs is scarce. Thus, this research focuses on the establishment of ultrasound-assisted extraction of proanthocyanidin compounds in brewing spent grains using a sonotrode. To set the sonotrode extraction up, response surface methodology (RSM) was used to study the effects of three factors, namely, solvent composition, time of extraction, and ultrasound power. Qualitative and quantitative analyses of proanthocyanidin compounds were performed using HPLC coupled to fluorometric and mass spectrometer detectors. The highest content of proanthocyanidins was obtained using 80/20 acetone/water (v/v), 55 min, and 400 W. The established method allows the extraction of 1.01 mg/g dry weight (d.w.) of pronthocyanidins from BSGs; this value is more than two times higher than conventional extraction.

scholarly journals Complete Sequence of a Staphylococcus aureus Clonal Complex 81 Strain, the Dominant Lineage in Food Poisoning Outbreaks in Japan

2017 ◽  
Vol 5 (34) ◽  
Author(s):  
Yusuke Sato’o ◽  
Junzo Hisatsune ◽  
Hideki Hirakawa ◽  
Hisaya K. Ono ◽  
Katsuhiko Omoe ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genome Sequence ◽  
Clonal Complex ◽  
Food Poisoning ◽  
Complete Sequence ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Content Type

ABSTRACT Staphylococcus aureus No. 10 is an isolate from a staphylococcal food poisoning outbreak in Japan, classified as clonal complex 81 subtype 1. It preferentially produces larger quantities of staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin H (SEH) in foods and media. Here, we report the complete annotated genome sequence of the chromosome and a plasmid.

scholarly journals Total Mercury and Methylmercury Distribution in Paguellus bellottii Fish from Soumbedioune Beach, Senegal

2020 ◽  
pp. 67-76
Author(s):  
Birame Ndiaye ◽  
Momar Ndiaye ◽  
Benita Pérez Cid ◽  
Abdoulaye Diop ◽  
Ibrahima Diagne ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Total Mercury ◽  
Microwave Digestion ◽  
Dry Weight ◽  
Mercury Content ◽  
Anova Analysis ◽  
Fish Tissues ◽  
Assisted Extraction ◽  
Ultrasonic Assisted ◽  
Ultrasonic Assisted Extraction

Paguellus bellottii fish proceeding from Soumbedioune beach (Senegal) were analyzed to evaluate their contents of total mercury and methylmercury. Simplified analytical procedures (microwave digestion and ultrasonic assisted extraction) were used for sample preparation. The total mercury content in fish varied between 0.0626-0.3542 µg/g, dry weight. The ANOVA analysis allows to conclude that significant differences (p <0.05) were not found between Paguellus bellottii fish from Soumbedioune beach. However, the mercury levels obtained were always lower than the European legislation limits for fish. The ratio methylmercury/total mercury varied between 42.3-42.8 % in fish tissues. A satisfactory correlation (p<0.0001; r = 1) was found between total mercury and methylmercury results.

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.

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.

Immunofluorescence Assay Using Monoclonal and Polyclonal Antibodies for Detection of Staphylococcal Enterotoxins A in Milk

2019 ◽  
Vol 13 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Tzonka Godjevargova ◽  
Zlatina Becheva ◽  
Yavor Ivanov ◽  
Andrey Tchorbanov
Keyword(s):  
Monoclonal Antibody ◽  
Magnetic Nanoparticles ◽  
Polyclonal Antibody ◽  
Polyclonal Antibodies ◽  
Food Poisoning ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Fluorescence Immunoassay ◽  
Magnetic Separator ◽  
Milk Samples

Objectives: Staphylococcus aureus is a Gram-positive microorganism. S. aureus can grow in various foods and cause food poisoning by secreting enterotoxins. The most common enterotoxins involved in food poisoning are staphylococcal enterotoxin A and staphylococcal enterotoxin B, but Staphylococcal Enterotoxin A (SEA) is predominant. The main types of food contaminated with SEs are meat and meat products, poultry and eggs, milk and dairy products. The aim of this study was to develop a rapid and sensitive fluorescence immunoassay for detection of staphylococcal enterotoxin A in milk. Methods: Monoclonal and polyclonal antibodies for SEA were produced and characterized. Competitive fluorescence immunoassay based on Magnetic Nanoparticles (MNPs) was performed and optimized. MNPs were used as a solid carrier of the antibodies. The first step of the assay was immunoreaction between the immobilized antibody onto MNPs and SEA in milk sample. Then the fluorescein-SEA conjugate was added to the sample. Thus, competitive immunoreaction between MNP-mAb/MNP-pAb with SEA and SEA-FITC was performed. These immuno-complexes were separated by a magnetic separator and the obtained supernatants were analyzed. The fluorescent signal from the excess of conjugated SEA was proportional to the SEA contained in the milk. The assay duration was only 30 min. Results: The fluorescence immunoassays performed with polyclonal antibody had linear ranges from 5 pg/mL to 100 ng/mL SEA in a buffer, and from 50 pg/mL to 50 ng/mL SEA in spiked milk samples. While the same assays performed with monoclonal antibody had linear ranges from 1 pg/mL to 20 ng/mL SEA in buffer, and from 10 pg/mL to 10 ng/mL SEA in spiked milk samples. The detection limits of the developed immunoassays performed in milk were: 48 pg/mL with polyclonal antibody and 9 pg/mL with monoclonal antibody. Conclusion: A rapid and sensitive fluorescence immunoassay based on magnetic nanoparticles with a polyclonal and monoclonal antibody for determination of staphylococcal enterotoxin A in milk was developed.

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