scholarly journals Enterotoxin A and B production in strains ofStaphylococcus aureusisolated from human beings and foods

1982 ◽  
Vol 88 (1) ◽  
pp. 103-106 ◽  
Author(s):  
D. Reali

SummaryThe production of enterotoxin A and B by strains ofStaphylococcus aureusisolated from nasal swabs of healthy carriers, from lesions of hospital patients and from foods unconnected with outbreaks of food-poisoning was investigated. Sixty-six strains ofS. aureuswere obtained from human beings, two produced enterotoxin A, 45 produced enterotoxin B. seven produced enterotoxins A + B. Thirty-six strains were isolated from 111 samples of food, one produced enterotoxin A, 16 produced enterotoxin B. The relative incidence of A, B and A + B enterotoxigenicity was assessed.

2007 ◽  
Vol 4 (1) ◽  
pp. 83-88
Author(s):  
Baghdad Science Journal

Thirty nine (12.8%) isolates of Staphylococcus aureus were isolated from 304 healthy human (Nasal swabs). It was found that percentage of males that have S. aureus is more than female's percentage. These isolates (39) were tested with different tests. Twenty seven isolates (69.23 %) were positive for Staphylococcus protein —A (SPA) ,thirty seven ( 94.8 %) were positive for tube coagulase , thirty five ( 89.7 % ) were positive with clumping factor and thirty two ( 82.05 %) had 13 — hemolytic on blood agar. It was found that 100% of the isolates (39 isolates) were positive with one, two or three tests (tube coagulase, clumping factor and SPA).


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 ◽  
...  

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.


1972 ◽  
Vol 35 (1) ◽  
pp. 21-29 ◽  
Author(s):  
T. E. Minor ◽  
E. H. Marth

Staphylococcal food poisoning is strictly an intoxication which is caused by a water-soluble protein called enterotoxin that is secreted by staphylococcal cells, i.e. an exotoxin. After a general discussion of the properties of the enterotoxins, methods and media employed for producing high toxin yields are detailed. Mechanisms whereby these toxins are secreted differ in that enterotoxin A behaves as a primary metabolite and enterotoxin B acts as a secondary metabolite. Several studies on and explanations of the synthesis of enterotoxins are presented. Assay methods for these toxins that are discussed include bioassay techniques and serological procedures. Finally, some general aspects of the epidemiology of staphylococcal intoxications are described.


2020 ◽  
Author(s):  
Mohammed Yahya ◽  
Hashim Abdalbagi Ali ◽  
Babbiker Mohammed Taher Gorish ◽  
Sara Omer Ali ◽  
Eman Saif Aldein Abdalrhim ◽  
...  

Abstract Background 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. Now days many researchers worldwide noted an emerging of resistant strains Staphylococci especially for the antibiotic Methicillin. Therefore, this study was aimed to determine the existence of Staphylococcus aureus and its enterotoxins, mecA genes in food samples. Results A total of 400 samples were collected from different areas in Khartoum state. The type of foods included Cheese, Meat products, Fish and Raw milk, 100 samples for each. out of 400 samples cultivated 137 (34.25%) isolates were identified as S. aureus, 126 (31.5%) were identified as bacteria other than S. aureus and 137 (34.25%) were yield no growth. Of 137 S.aureus isolates, 84 were randomly selected and examined for the presence mecA and enterotoxin genes products. Oxacillin sensitivity test showed that 15(11%) of 137 S.aureus isolates were Oxacillin resistant. The PCR assay showed that mecA gene was detected in 15 of 84 (17%) S. aureus isolates. While only 2 (2.385%) out of 84 S. aureus isolates were show an enterotoxin B gene product. Conclusion There was a relatively moderate prevalence of Methicillin resistant staphylococcus aureus with very low frequency of enterotoxin B gene in different kinds of food samples which collected from Khartoum state. These findings highlight the high potential risk for consumers of meat and dairy products especially in the absence of strict hygienic and preventive measures to avoid Staphylococcus aureus enterotoxins production in foods.


2020 ◽  
Author(s):  
Mohammed Yahya ◽  
Hashim Abdalbagi Ali ◽  
Babbiker Mohammed Taher Gorish ◽  
Sara Omer Ali ◽  
Eman Saif Aldein Abdalrhim ◽  
...  

Abstract Background: 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. Now days many researchers worldwide noted an emerging of resistant strains Staphylococci especially for the antibiotic Methicillin. Therefore, this study was aimed to determine the existence of Staphylococcus aureus and its enterotoxins, mecA genes in food samples.Results: A total of 400 samples were collected from different areas in Khartoum state. The type of foods included Cheese, Meat products, Fish and Raw milk, 100 samples for each. out of 400 samples cultivated 137 (34.25 %) isolates were identified as S. aureus, 126 (31.5%) were identified as bacteria other than S. aureus and 137 (34.25%) were yield no growth. Of 137 S. aureus isolates, 84 were randomly selected and examined for the presence mecA and enterotoxin genes products. Oxacillin sensitivity test showed that 15(11%) of 137 S.aureus isolates were Oxacillin resistant. The PCR assay showed that mecA gene was detected in 15 of 84 (17%) S. aureus isolates. While only 2 (2.385%) out of 84 S. aureus isolates were show an enterotoxin B gene product. Conclusion: There was a relatively moderate prevalence of Methicillin resistant staphylococcus aureus with very low frequency of enterotoxin B gene in different kinds of food samples which collected from Khartoum state. These findings highlight the high potential risk for consumers of meat and dairy products especially in the absence of strict hygienic and preventive measures to avoid Staphylococcus aureus enterotoxins production in foods.


2018 ◽  
Vol 15 (2) ◽  
pp. 211-221
Author(s):  
Nguyễn Thị Hoài Thu ◽  
Nghiêm Ngọc Minh

Staphylococcal enterotoxins (SEs) secreted by Staphylococcus aureus is one of the principal causes of food poisoning. The SEs are superantigens; they are highly stable, resisting most proteolytic enzymes and thus keeping activity in the gastrointestinal tract after being ingestion. In particular, heat-stable enterotoxin is one of the most important property related to food safety. They are not degraded at 100°C for 30 minutes, even at 121oC for 28 minutes, the SEs retain biological activity. Heat resistance of SEs in foods is higher than in the culture medium. Staphylococcus aureus (S. aureus) produces more than 20 different types of enterotoxins, including SEA to SEE, SEG to SER and SEU. Among these, Staphylococcal enterotoxin B (SEB) is a powerful toxin, heat-stable, water-soluble and is a common cause of food poisoning. Moreover, SEB is one of the harmful or hazardous agents used as biological weapons in bioterrorism or biological warfare. Therefore, determining presence of SEB toxin in food is extremely important. In this review, we introduce the most basic features about S. aureus; about SEB toxin and conventional methods for SEB diagnosis, detection. Especially, we focus on rapid detection strip based on an immunochromatography; this technique is an highly sensitive, rapid, easy for use and storage.


2020 ◽  
Author(s):  
Mohammed Yahya ◽  
Hashim Abdalbagi Ali ◽  
Babbiker Mohammed Taher Gorish ◽  
Sara Omer Ali ◽  
Eman Saif Aldein Abdalrhim ◽  
...  

Abstract Background: 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 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.Results: 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 sample 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 the137 S. aureus isolates were randomly selected and tested for the presence of mecA and enterotoxin genes. 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. Conclusion: 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 that 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.


Aim: The objective of this study was to assess the occurrence and molecular characteristics of Staphylococcus aureus isolates among camel and human samples in Aswan. Materials and Methods: A total of 320 samples: milk, nasal swabs and bus swabs were collected from camels (n= 290) and their human contacts (n= 30) from Aswan governorate. Disc diffusion test was applied to detect resistant and Methicillin-resistant Staphylococcus aureus MRSA isolates. PCR was applied for detection of the virulence genes: nuc, hla, pvl, mecA, vanA, vanB and enterotoxins (sea, seb sec and sed) genes. Results: 112 Out of 165 she camel milk samples (67.9%), 59 out of 125 camel nasal samples (47.2%), 3 out of 5 worker nasal swabs (60%) and 16 out of 25 abscesses' swabs from human infected wound (64%) were positive for staphylococci. Only 34 out of 190 staphylococci were S. aureus (17.9%) and they were tested by PCR of the nuc gene. All S. aureus isolates were sensitive to vancomycin. The two human isolates were resistant to streptomycin and erythromycin. Among 25 % of S. aureus isolated from camel milk samples were resistant to gentamicin and ceftriaxone (each), 50% and 31.2 % were resistant or intermediate resistant to streptomycin and clindamycin respectively. Among S. aureus isolated from camel nasal swabs, 18.8% were resistant or intermediate resistant to cefoxitin and ceftriaxone (each). 13 out of 34 S. aureus isolates (38.2%) were MRSA. All S. aureus isolates were amplified 279 bp of nuc gene specific for S. aureus strains. While 28, 12 and 11 isolates were harboring hla, mecA and pvl genes respectively. All S. aureus isolates were negative for vanA, vanB and enterotoxins (sea, seb sec and sed) genes. Conclusion: S. aureus and MRSA isolated from camel milk considered a potential health risk for food poisoning.


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 ◽  
...  

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.


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