Molecular Detection of Enterotoxin Genes of Multiresistant Staphylococcus aureus Isolates from Different Sources of Food

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.

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.


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.


2020 ◽  
pp. 3164-3171
Author(s):  
Andalus S. Atiyah ◽  
Marwa H. Alkhafaji

The microbial production of substances that have the ability to inhibit the growth of other microorganisms is possibly the most common defense strategy developed in nature. Microorganisms produce a variable collection of microbial defense systems, which include antibiotics, metabolic by-products, lytic agents, bacteriocins and others. The aim of the present study was to isolate and identify Enterococcus spp. and  its most prevalent species from food samples and determine its antibacterial activity against Staphylococcus aureus isolates. A total of 50 food samples from different sources (dairy products (20 samples) and vegetables and fish (15 samples each)) were collected from different local markets in Baghdad and cultured. Enterococcus spp were isolated from only 32 food samples. E. faecium was the most predominant species which was recovered from 20 samples (62.5 %), 10 dairies, 7 vegetables, and 2 fish. E. faecalis was found in 8 samples (25 %), 5 vegetables and 3 fish.  E. avium was recovered 6.25% as well as E. gallinarium (2 samples for each) Enterococcus avium were all isolated from dairy products but Enterococcus gallinarium one sample isolated from dairies and the other from fish. This study indicates the presence of Enterococcus spp. in the food samples and the ability of these bacteria to produce antibacterial substances which are active against closely related clinical isolates.


2016 ◽  
Vol 60 (4) ◽  
pp. 417-421
Author(s):  
Muhammad Luqman Sohail ◽  
Muhammad Sarwar Khan ◽  
Muhammad Avais ◽  
Muhammad Yasir Zahoor ◽  
Irfan Khattak ◽  
...  

Abstract Introduction: Leptospirosis affects a wide range of mammals, humans, and even a few poikilothermic animal species. In Pakistan, serological studies of equine leptospirosis have reported a prevalence of over 40%, but no study has ever been conducted towards molecular detection of Leptospira in horses. Material and Methods: Blood samples from 128 horses were screened using ELISA and 41 positive samples were examined for the presence of leptospiral DNA using specific primers for 16S rRNA gene. Results: Out of 41 tested samples, 20 samples were found to be PCR-positive, revealing a fragment of 306 bp after gel electrophoresis. Sequencing and phylogenetic analysis of positive samples revealed circulation of pathogenic Leptospira spp. in Pakistani horses. No evidence of circulation of intermediate species was found in this study. Conclusion: This study reports the first molecular evidence of equine leptospirosis in Pakistan and lays ground for further research in this area. It also confirms the efficiency of 16S rRNA for the diagnosis of equine leptospirosis.


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.


2019 ◽  
Author(s):  
Mina Mahmoudi ◽  
Maryam Mohamadian ◽  
abbas maleki ◽  
nourkhoda Sadeghifard ◽  
sobhan ghafourian

Abstract Objectives: Staphylococcus aureus could be considerable pathogenic bacterium because it can be changed from a microbiome to a lethal pathogen. Another remarkable ability of this bacterium is its colonization ability, which has been cloned in one-third of the world's population. Also, one of the most important issue in S. aureus is its severe resistance to antibiotics, which can lead to failure in antimicrobial therapy in many diseases such as abscesses, sinusitis, food poisoning, toxic shock syndrome, atopic dermatitis as well as it is one of the five major causes of nosocomial infections, especially post- surgical ulcers. therefore, find a novel antimicrobial target for S. aureus is crucial. Some studies demonstrated that toxin antitoxin systems can be the regulon for controlling the pathogenic bacteria. To identify the reliable antimicrobial targets, bioinformatics analysis before any experimental study could be helpful. Results: we evaluate the potent TA loci of 36 S. aureus strains by bioinformatics analysis. As regards, this analysis was performed with Rasta data base, toxin antitoxin systems distributions were seen in all scores and the htx-xre has the preponderance total frequency, which we hope will be beneficial for further researches.


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