Antimicrobial-resistant genes associated with Salmonella spp. isolated from human, poultry, and seafood sources
Article first published online: 26 MAY 2014
© 2014 The Authors. Food Science & Nutrition published by Wiley Periodicals, Inc.
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Food Science & Nutrition
Volume 2, Issue 4, pages 436–442, July 2014
How to Cite
Food Science & Nutrition 2014; 2(4): 436–442
- Issue published online: 11 JUL 2014
- Article first published online: 26 MAY 2014
- Manuscript Accepted: 6 APR 2014
- Manuscript Revised: 31 MAR 2014
- Manuscript Received: 27 DEC 2013
- Indian Council of Medical Research, Government of India. Grant Number: AMR/37/2011/ECD-1
- Centre for International Co-operation in Science
- Antimicrobial resistance;
- resistant genes;
Antimicrobial-resistant salmonellosis is a significant public health concern globally. A study was conducted to screen for Salmonella species from a total of 120 samples, of which 50 were retail meat samples purchased from five randomly selected sales outlets in the city of Mangalore, India. Twenty poultry fecal materials freshly voided before slaughter were obtained with sterile spatula and placed in sterile sealable polythene envelopes, and 20 clams were purchased from the estuaries of Nethravathi and Kankarnady market. In addition, 30 clinical isolates from Nigeria suspected to be Salmonella by only cultural characterization were also included in the study. In all, 30 samples—6 poultry, 8 seafood, and 16 Salmonella isolates from clinical samples—were confirmed positive by PCR and used in this study. The disk-diffusion test was performed to determine the zone of inhibition, and detection of resistance genes was tested by PCR targeting various antimicrobial genes. Resistance to tetracycline (TET), cotrimoxazole, nalidixic acid, nitrofurantion, and piperacillin/tazobactin was found in 66.7%, 60%, 53.3%, 50% and 50% of the isolates, respectively. About 60–100% of MDR isolates possessed antibiotic-resistant genes, of the tetracyclines resistant isolates, 20 (100%) 6 (30%), 7 (35%), and 10 (50%) carried tetA, tetB, tetC, and tetG genes, respectively. Of 18 cotrimoxazole-resistant strains, 18 (100%), 14 (77.7%), and 4 (22.2%) had sul1, sul2, and sul3 genes, respectively. Of the 14 multidrug-resistant isolates tested, 8 (61%) and 9 (69%) were positive for cmlA and cmlB genes, respectively, 10 (1.4%) tested positive for aph(3)11a genes, 8 (57%) tested positive for aac(3)lla, while none was positive for the aac6 gene. The results show the presence of antibiotic-resistant Salmonella spp. in food samples from India and in human samples from Nigeria.