scholarly journals Molecular detection of Staphylococcal enterotoxins and mecA genes products in food samples collected from different areas in Khartoum state.

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.


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.


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.


2010 ◽  
Vol 73 (7) ◽  
pp. 1325-1327 ◽  
Author(s):  
JAROSŁAW BYSTROŃ ◽  
MAGDALENA PODKOWIK ◽  
KAMILA KORZEKWA ◽  
ELŻBIETA LIS ◽  
JERZY MOLENDA ◽  
...  

In this study, the molecular characteristics of food-derived oxacillin-resistant Staphylococcus aureus were determined. Eight borderline oxacillin-resistant strains with MICs of 2 to 4 μg/ml were identified from 132 S. aureus isolates of food origin. One of the two isolates with a MIC of 4 μg/ml was methicillin-resistant determinant (mecA) gene positive, and the other six with MICs of 2 μg/ml were mecA negative. The mecA-positive isolate was classified as sequence type (ST)228, staphylococcal protein A (spa) type t041, and carried the staphylococcal cassette chromosome mec type I element. Two borderline oxacillin-resistant strains were classified as spa t008 and ST8, and the remaining five as spa t164 and ST20. The mecA-positive strain and four borderline oxacillin-resistant strains were found enterotoxigenic. The enterotoxin genes detected in these strains included selp, egc1, and sed-sej-selr. The borderline-resistant S. aureus isolates from a manually handled product, i.e., minced pork, were shown genetically related to strains associated with human infections. This suggests that humans can be considered as a source of contamination of this food with oxacillin-resistant S. aureus strains. The genotypes of the investigated milk borderline-resistant isolates were shown to occur not only in cows, but also in humans. Since manual handling is reduced in raw milk production, a human origin of S. aureus seems unlikely. Because knowledge of the genotypes of animal staphylococci is limited, more research is needed to address the question of the origin of antibiotic-resistant S. aureus strains in food.


2016 ◽  
Vol 60 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Magdalena Kizerwetter-Świda ◽  
Dorota Chrobak-Chmiel ◽  
Magdalena Rzewuska ◽  
Joanna Pławińska-Czarnak ◽  
Marian Binek

Abstract Introduction: Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) belonging to the clonal complex 398 (CC398) emerged recently in livestock as a new type of MRSA, which may cause zoonotic infections. This study presents data on the characterisation of S. aureus isolated from the meat processing plants. Material and Methods: S. aureus was isolated from 90 samples collected in the raw meat warehouse, from devices and surfaces of meat processing plants, and from finished meat products. The isolates were subjected to molecular analysis in order to investigate the presence of enterotoxin genes, the mecA gene, and to verify whether they belong to the clonal complex 398. The genetic relatedness of the isolates was determined using pulsed-field electrophoresis. Likewise, antimicrobial susceptibility was tested. Results: From 21 S. aureus strains isolated, five belonged to the CC398, two of which were recognised as MRSA and three as methicillin-sensitive Staphylococcus aureus (MSSA). The most prevalent enterotoxin genes were seg and sei. Two MRSA CC398 isolates, three MSSA CC398, and one MSSA were classified as multidrug-resistant. Conclusion: The first isolation of MSSA CC398 from beef in Poland indicates contamination of beef by strains belonging to this clonal complex. The occurrence of multidrug-resistant enterotoxigenic S. aureus isolates in the finished meat products constitutes a potential risk for the consumers.


2021 ◽  
Author(s):  
Seraphine Nkie Esemu ◽  
Sally Tabe Njoh ◽  
Lucy M. Ndip ◽  
Nene Kaah Keneh ◽  
Jerome Achah Kfusi ◽  
...  

Background The consumption of ready-to-eat (RTE) foods contaminated with coagulase-positive staphylococci (CoPS) and especially Staphylococcus aureus puts consumers at potential risk of foodborne disease or colonization and subsequent infection. This cross-sectional study determined the levels of CoPS and the presence of S. aureus in RTE foods sold in Buea municipality. Method A total of 420 RTE food samples comprising 70 each of cake, bread, fruit salad, meat-hot-pot, suya and boiled rice were randomly purchased from February to August 2020. The CoPS counts were determined by culturing on Baird-Parker agar and S. aureus identified by amplification of the nuc gene using polymerase chain reaction. All S. aureus isolates were screened for the presence of classical staphylococcal enterotoxin genes and each isolate challenged with 11 antibiotics to determine their antibiotic susceptibility profiles. Oxacillin-resistant S. aureus were analyzed for the presence of mecA gene. Result Overall, 161 (38.3%) samples had detectable levels of coagulase-positive staphylococci ranging from 2.0-5.81 log10CFU/g. Based on CoPS levels, 37 (8.81%) of the 420 RTE food samples, only fruit salad and meat-hot-pot, had unsatisfactory microbiological quality. A total of 72 S. aureus isolates, comprising 52.78% from fruit salad, 16.67% from meat-hot-pot, 12.5% from boiled rice, 9.72% from suya, 5.56% from bread and 4.17% from cake were recovered. None of the S. aureus isolates possessed any of the classical enterotoxin genes. All the isolates were sensitive to vancomycin and ofloxacin while 68 (94.44%) and 66 (91.67%) were sensitive to oxacillin and ciprofloxacin, respectively. Resistance to penicillin (93.06%) was highest followed by amoxicillin (91.67%) and erythromycin (79.17%). Four isolates were identified as methicillin-resistant S. aureus all of which carried the mecA gene. A total of 24 antibiotypes were identified. Conclusion Our findings showed that RTE foods sold in the Buea municipality are likely vehicles for transmission of CoPS and antibiotic-resistant S. aureus.


2021 ◽  
pp. 61-74
Author(s):  
Sundus A. Jassim ◽  
Nuha J. Kandala

Foodborne diseases are a major risk for human health. Millions of people become sick as a result of eating contaminated food with microorganisms that cause diseases. S.  aureus is considered as one of the most important pathogenic bacteria, having the ability to  activate certain genes that encode for heat stable enterotoxins and cause Staphylococcal food poisoning. Thus, this study aimed to determine the prevalence of multi resistant Staphylococcus aureus that produce enterotoxins in different sources of food . Forty nine isolates were identified as S.aureus, according to morphological and biochemical tests. They were isolated from 387 different food samples from several randomly covered restaurants and supermarkets in different regions of Baghdad. Molecular diagnosis of S. aureus using specific primers for the 16S rRNA gene was carried out by Polymerase Chain Reaction (PCR ) technique . Susceptibility of 43 isolates of S.aureus was tested against 15 antimicrobial agents. The results revealed that all the isolates were resistant (100%) to mecillinam, highly resistant to vancomycine and meropenemin  (74.4 %) and  moderately resistant to Oxacillin, Erythromycin Cefotaxime, and Cefiximein (67.4, 60.4, 62.8, , 60.5 %, respectively), while they showed low resistance to Gentamicin (34.8%). In addition, all of these isolates were susceptible  to Tigecycline and Amoxicillin/ clavulanic acid and Cefoxitin-Cloxacilin. High percentages of oxicillin resistant S. aureus were isolated from cooked food samples, followed by meat products, and with less percentage from pastry products. Molecular detection of enterotoxins A and B of Staphylococcus aureus isolates was performed using specific primers based on PCR. The results revealed that S. aureus isolated from cooked food had the highest percentage of the isolates producing the enterotoxins A and B. Type A enterotoxin gene showed a higher prevalence than type B gene among cooked food , dairy products and pastry. In conclusion, the results revealed a high prevalence of some classical enterotoxin genes in  multi-drug resistant S.aureus isolated from different sources of food, which can cause food-poisoning  and, consequently, a potential serious problem for public health.


Author(s):  
Fatima N. Aziz ◽  
Laith Abdul Hassan Mohammed-Jawad

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.


2008 ◽  
Vol 71 (10) ◽  
pp. 2094-2099 ◽  
Author(s):  
YU-CHANG CHANG ◽  
JAN-YI WANG ◽  
AMMAIYAPPAN SELVAM ◽  
SHU-CHEN KAO ◽  
SHANG-SHYNG YANG ◽  
...  

Aeromonads possess an array of virulence factors and are causative agents of a number of human infections. Among them, genes of one cytotoxic (Act) and two cytotonic (Alt, Ast) enterotoxins are implicated in a human diarrheal disease. A rapid, specific, simultaneous detection of these enterotoxin genes in suspected food poisoning samples is not yet reported. Hence, a multiplex PCR assay was designed to amplify the cytotoxic (act), heat-labile cytotonic (alt), and heat-stable cytotonic (ast) enterotoxin genes of aeromonads. The PCR assay was tested with 133 Aeromonas spp. isolated from suspect food poisoning samples and retail samples of poultry and fish from wet markets in and around Taipei, Northern Taiwan. The Aeromonas spp. isolates were divided into six genotypes based on absence or presence of one or more enterotoxin genes. Of these 133 isolates, Aeromonas caviae (52.5%) and Aeromonas hydrophila (43.4%) were the most frequently isolated species from food poisoning samples and retail samples, respectively. Among the species, A. hydrophila had a significantly higher proportion for harboring three enterotoxin genes than had the others, whereas Aeromonas encheleia, considered a nonpathogen, was found harboring three enterotoxin genes. The multiplex PCR assays are rapid and specific, and provide a useful tool for the detection and genotyping of enterotoxin genes of aeromonads.


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