Frequency and antibiotic resistance pattern of Salmonella spp. isolated from traditional dairies and raw milks collected in Yazd province, Iran
Abstract
Background and Objectives: Salmonellosis is among the most common food-born infections, caused by Salmonella spp. bacteria. Present study has investigated the frequency and antibiotic resistance pattern of Salmonella spp. isolated from tra- ditional dairy products and raw milk supplied in Yazd, Iran.
Materials and Methods: In a cross-sectional study, 350 samples of raw milk and traditional dairy products were randomly collected from July to September 2018. Following culturing the samples, isolates went through biochemical tests for pheno- typic identification. Results were confirmed through PCR technique by targeting invA gene. Antimicrobial susceptibility test was conducted by means of disk diffusion method.
Results: The rate of contamination with Salmonella bacteria was 6.57% in all samples. The PCR assay of all isolates showed that 23 isolates (100%) carried the invA gene. No significant association between the frequency of salmonella spp. and types of dairy and their origin was reported (P>0.05). The highest antibiotic resistance rate among the isolates belonged to tetracy- cline (34.8%) and the highest sensitivity was seen to imipenem, cefepime, and cefotaxime (each 91.3%).
Conclusion: According to our results there has been a rise in multiple drug resistance and contamination rate in traditional dairy products in Yazd province.