Detection and antibiotic resistance pattern of Listeria monocytogenes strains isolated from curd and cheese

Subject Areas : Food Microbial Contamination

Rahil Kiyanpour Berjoee ¹ , Hassan Momtaz ² , Lida Lotfollahi ³ , zahra bamzaheh ⁴

1 - PhD student of Microbiology, Department of Microbiology, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
2 - Department of Microbiology, Shahrekord Branch, Islamic Azad University Shahrekord, Iran
3 - Department of Microbiology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University Shahrekord, Iran Department of Microbiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
4 - Department of Microbiology, Shahrekord Branch, Islamic Azad University, Shahrekord-Iran;Department of Microbiology, Shahre-Qods Branch, Islamic Azad University Tehran, Iran

Received: 2021-11-15 Accepted : 2021-12-23 Published : 2022-12-22

Keywords: PCR, Antibiotic resistance, Listeria monocytogenes, Cheese,

Abstract :

Listeria monocytogenes is a foodborne pathogen that causes listeriosis in humans and animals. Microbial contamination of food usually leads to widespread food poisoning in the form of widespread epidemics in the region, which is very significant in terms of public health and is one of the most important issues in developing countries. The aim of this study was to determine the contamination of Listeria monocytogenes in dairy products using culture method and final confirmation by PCR method. In this study, 150 different dairy samples offered in the market were purchased randomly. The samples were transferred to the laboratory under hygienic conditions and examined. In addition to culture medium experiments, positive samples were evaluated for final confirmation and identification of the pathogen by molecular PCR.14 (9.33%) positive samples including 6 samples of white cheese (4%), 4 samples of cream cheese (2.6%), and 3 samples of curd (2%) were positive for contamination. Antimicrobial susceptibility to 16 antibiotics was highly sensitive to clindamycin (47.37%). It is noteworthy that it was resistant to several drugs.The presence of Listeria monocytogenes in dairy products (cheese, cream cheese, and whey) was proven. Based on the results, people who consume contaminated dairy products are at potential risk of listeriosis. As a result, food safety authorities must establish an effective standard for examining the presence of Listeria in food.