|LADELY, SCOTT - Food Safety Inspection Service (FSIS)|
|Meinersmann, Richard - Rick|
|OAKLEY, BRIAN - Former ARS Employee|
|Cox, Nelson - Nac|
Submitted to: International Association for Food Protection
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2016
Publication Date: 7/31/2016
Citation: Ladely, S.R., Berrang, M.E., Meinersmann, R.J., Oakley, B., Cox Jr, N.A. 2016. Campylobacter MLST Subtypes and Antimicrobial Susceptibility of Broiler Cecal Isolates: A Two Year Study from 142 Commercial Flocks. International Association for Food Protection. P1-162.
Technical Abstract: Introduction: Campylobacter spp. are recognized as important agents of human foodborne gastroenteritis. To monitor trends in food safety and public health, antimicrobial susceptibility testing of Campylobacter derived from poultry products and infected patients has become common practice in both regulatory food safety and public health programs. Purpose: The objective of this study was to assess genetic diversity and antimicrobial susceptibility of Campylobacter jejuni and coli recovered from broiler ceca at slaughter. Methods: The ceca from a broiler were collected from the evisceration line in a commercial processing plant, once or twice weekly for two years. Campylobacter were cultured from the cecal contents and analyzed by whole genome sequencing, multi-locus sequence typing (MLST) and antimicrobial susceptibility testing. Results: Seventy-two of 142 birds examined were positive for Campylobacter. A total of 24 sequence-types (ST) were identified (Simpson’s Index of Diversity [SID] 0.93) belonging to ten Campylobacter MSLT clonal complexes (SID 0.68). Two MLST clonal complexes, ST-353 (53.2%) and ST-828 (17.7%), accounted for the majority of Campylobacter isolates recovered. Compared to all other clonal complexes, a significantly higher percentage (P<0.05) of C. coli isolates belonging to ST-828 complex were resistant to azithromycin, clindamycin, erythromycin, gentamicin and telithromycin. No significant differences in antimicrobial resistance among clonal complexes were observed for ciprofloxacin, nalidixic acid, or tetracycline. No isolates were resistant to florfenicol. Significance: Despite high genetic diversity among Campylobacter recovered from broiler ceca during this two year study, antimicrobial resistance to aminoglycosides (gentamicin), macrolides (azithromycin and erythromycin) and lincosamides (clindamycin) was significantly linked to one MLST clonal complex (ST-828).