Study the frequency of enterotoxin encoding genes and antibiotic resistance pattern of methicillin-resistant Staphylococcus aureus isolated from vegetable and salad samples in Chaharmahal Va Bakhtiari province

Subject Areas : Food-Borne Diseases

Manouchehr  Momeni shahraki ¹ (Young Researchers Club,Master of Health and Quality Control of Food, Faculty of Veterinary Medicine, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran)
Amir  Shakerian ² (2Department of Food Hygiene, Faculty of Veterinary Medicine, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.)
Ebrahim  Rahimi ³ (Department of Food Hygiene, Faculty of Veterinary Medicine, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.)
Farhad  Safarpoor Dehkordi ⁴ (Halal Research Center of IRI, FDA, Tehran, Iran.)

Received: 2019-08-27 Accepted : 2019-11-26 Published : 2020-06-21

Keywords: Antibiotic resistance, Enterotoxin, Vegetables, Salad, Staphylococcus aureus resistant to methicillin,

Abstract :

Methicillin-resistant Staphylococcus aureus (S. aureus) is one of the main emerging causative agents of antibiotic-resistant food poisoning in humans. The bacterium also has the ability to the production of heat resistant enterotoxin. The present study was done to assess the prevalence rate, antibiotic resistance pattern, and frequency of enterotoxin encoding genes in methicillin-resistant S. aureus strains isolated from vegetable and salad samples. In this study, 485 samples of vegetables and salad were collected and immediately transferred to the laboratory. The microbial culture was used to isolate S. aureus, and methicillin-resistant strains were approved using cefoxitin and oxacillin disks. Antibiotic resistance patterns and frequency of enterotoxin encoding genes were analyzed using disk diffusion and PCR methods, respectively. The prevalence rate of methicillin-resistant S. aureus in vegetable and salad samples were 7.2% and 8.51%, respectively. Methicillin-resistant S. aureus strains had the highest antibiotic resistance against penicillin (100%), co-amoxiclav (100%), ampicillin (100%) and ceftriaxone (100%) antibiotics. The prevalence of resistance against imipenem (10.52%) and chloramphenicol (23.68%) was lower than other antibiotics. SEA (63.15%) and SEB (52.26%) were the most frequently detected enterotoxins in methicillin-resistant S. aureus strains. The simultaneous presence of multiple enterotoxin encoding genes and multiple resistance against several antibiotics in methicillin-resistant S. aureus strains isolated from vegetable, and salad samples represent an important health-related concern in this kind of food samples. Preventing uncontrolled administration of antibiotics can reduce the risk of enterotoxigenic methicillin-resistant S. aureus enterotoxin in vegetables and salads.