Studies on prevalence, virulence genes and antimicrobial resistance of thermophilic campylobacters isolated from poultry farms of Kumaon region
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Date
2017-07
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G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand)
Abstract
Thermophilic campylobacters are leading cause of food-borne gastroenteritis worldwide and considered a major food safety concern. With highly complex epidemiological cycle and multiple sources of contamination, it is critically important to create a framework of effective measures to control these organisms. The present work was carried out to study the prevalence of thermophilic campylobacters in eight poultry farms located in the Kumaon region (Haldwani, Pantnagar, Bazpur, Ramnagar, Kiccha, Jawaharnagar and Bindukhatta) of Uttarakhand state, India. A total 545 samples comprising 345 poultry faecal and 199 environmental samples (51 litter, 52 feed, 50 water and 46 manure) were processed for Campylobacter isolation. Respective protocols were used for Campylobacter isolation from poultry faeces and environmental samples. The organisms with typical morphological and staining characteristics were confirmed biochemically. Genus specific PCR targeting 16S rRNA gene (816 bp) and a multiplex PCR targeting lpxA gene for simultaneous identification of C. jejuni (331 bp) and C. coli (391 bp) was used. A total of 67 Campylobacter isolates were recovered with an overall prevalence of 12.29%. Highest prevalence was detected in Bazpur farm (31.4%) followed by Pantnagar farm 2 (25.0%), Pantnagar farm 1 (24.4%), Haldwani farm (16.3%), Bindukhatta farm (7.5%) and Jawaharnagar farm (5.6%). No isolate was detected from Kiccha and Ramnagar farms. Out of total 67 Campylobacter isolates, 51 (76.11%) were identified as C. coli and 16 (23.88%) as C. jejuni. C. coli was found to be more prevalent than C. jejuni. Only 48 isolates were screened for detection of virulence genes. The cadF and flaA gene was present in all 48 isolates, while 6 (12.5%), 44 (91.66%) and 11 (22.9%) isolates harboured ciaB, cdtB and cgtB genes, respectively. None of the isolates was positive for wlaN gene. Kirby Bauer disc diffusion assay was used for antibiotic sensitivity testing of 42 Campylobacter isolates. Most frequent resistance was observed for cefoxitin (97.9%), followed by ciprofloxacin (64.28 %), nalidixic Acid (33.33 %), ampicillin (28.5%), ceftriaxone (14.28), tetracycline (4.76%), clindamycin (2.38%), sulfafurazole (2.38%) and erythromycin (2.38%). All isolates were susceptible to levofloxacin and gentamicin. Campylobacter isolates showing phenotypic resistance were screened for the presence of corresponding antimicrobial resistance genes (ARGs). β-lactam resistance gene blaOXA-61 was detected in 18 (58.06%) isolates. Resistance genes cmeB and tet(O) were detected in 19 (79.16%) and 2 isolates (100%) respectively. The ermB gene was absent in a single erythromycin resistant isolate. Risk factor analysis revealed significant association between the use of feed purchase from market and Campylobacter positivity at farm. The study focuses on the presence of the Campylobacter in poultry faeces and its associated environment which could be significant sources to humans. Higher resistance to cefoxitin and ciprofloxacin along with detection of multiple antimicrobial resistance genes in poultry faecal and environmental isolates warrants strict measures for judicious use of antimicrobials in poultry farms.
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