| Abstract: | Anti‐microbial resistance is an emerging public health issue. Farmed animals may act as reservoirs and potential sources of anti‐microbial resistant Campylobacters. The aim of this study was to investigate the anti‐microbial resistance profile of cattle and environmental Campylobacter isolates from normal untreated feedlot cattle, the role of the gyrA Thr‐86‐Ile mutation in ciprofloxacin‐resistant Campylobacter jejuni isolates and the involvement of the tripartite CmeABC efflux system for multi‐resistant C. jejuni isolates. The phenotypic anti‐microbial resistance testing was carried out on 500 Campylobacter isolates (445 cattle isolates and 55 environmental isolates). In general, there was a higher level of anti‐microbial resistance for the environmental isolates compared with the animal isolates, 45% of the animal isolates were resistant to one or more of the seven anti‐microbials compared with 84% of the environmental isolates. The combined cattle and environmental Campylobacters had 34 (6.8%) isolates resistant to three or more of the seven anti‐microbials tested on all isolates and 11 (2.2%) isolates were resistant to the seven anti‐microbials. There was a substantial level of ciprofloxacin‐resistant Campylobacters in both animal (8.5%) and environmental (21.8%) isolates. The gyrA Thr‐86‐Ile mutation was only present in five of 22 ciprofloxacin‐resistant C. jejuni isolates investigated. No multi‐drug‐resistant associated mutation was detected in the CmeB or the CmeR regions investigated. In conclusion, our study observed a substantial level of Campylobacter anti‐microbial resistance, highlighting the need for an active anti‐microbial surveillance program for food animals in Ireland and the importance of the chosen sampling point can have on the findings of such a program. |
