Journal of Food Quality and Hazards Control 2 (2015) 101-106 Journal website: http://www.jfqhc.com Occurrence and Antibiotic Resistance of Listeria monocytogenes in Retail Minced Beef Distributed in Ahvaz, South-West of Iran S. Maktabi * , M. Pourmehdi, M. Zarei, R. Moalemian Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Iran Abstract Background: Listeria monocytogenes is one of the most important food-borne bacteria causing septicemia, meningitis and encephalitis in humans. The objective of this study was to evaluate the occurrence and antibiotic resistance of the bacterium in retail minced beef in Ahvaz, South-West of Iran. Methods: In this survey, 150 samples of minced beef were randomly obtained from retail butcheries in Ahvaz, Iran and tested for presence of L. monocytogenes. The proce- dure was one-step enrichment in Listeria enrichment broth followed by plating on oxford agar. Isolated colonies were subjected to subsequent biochemical tests and poly- merase chain reaction (PCR) assay using the target iap-P60 gene encoding P60 protein. Susceptibility of the isolates to various antibiotics was investigated by Kirby-Bauer disk diffusion method. The results were analyzed by chi-square test and fisher’s exact test us- ing SPSS 16.0 software. Results: The incidence of Listeria spp. was 2.7% (4 of 150 samples) and only one sample (0.66%) was contaminated to L. monocytogenes. Statistical analysis showed no significant difference in prevalence of Listeria between various regions (p>0.05). The isolate was resistant to streptomycin and showed an intermediate susceptibility to tetracycline and penicillin. However, it was sensitive to other tested antibiotics. Conclusion: Our findings showed the presence of antibiotic resistant L. monocytogenes strain among beef samples in this region of Iran and so, indicated the potential risk for public health from consumption of raw or undercooked beef which may increase the possibility of acquisition of resistance to antibiotics. Introduction Listeria monocytogenes, the most important species of Listeria spp., is commonly present in food, water, feed, soil and sewage. This food-borne pathogen causes acute complications such as septicemia, meningitis and en- cephalitis in humans especially infants, pregnant women, the elderly people and also immune-compromised per- sons (Boughattas and Salehi, 2014; Drevets and Bronze, * Corresponding author E-mail: s.maktabi@scu.ac.ir 2008; Rahimi et al., 2012a; Rahimi et al., 2012b). Listeria can grow at low temperatures with an optimum pH requirement of 5.4-9.6 (Jalali and Abedi, 2008; McLauchlin et al., 2004). Antimicrobial resistance of pathogenic microorganisms is a worldwide public health concern because of increas- ing global trade and travelling (Doyle et al., 2013). L. monocytogenes is naturally susceptible to various anti- Article type Original article Keywords Listeria monocytogenes Meat Polymerase Chain Reaction Drug Resistance, Microbial Received: 14 May 2015 Revised: 24 June 2015 Accepted: 19 July 2015 Downloaded from jfqhc.ssu.ac.ir at 21:20 +0330 on Wednesday November 24th 2021