Fluoroquinolone resistance is associated with aerobic survival and is found at high levels in Campylobacter strains isolated from supermarket chicken.

Abstract S9

Presenter: Gillian Carney (University College Dublin)

Campylobacter jejuni is the leading cause of bacterial diarrhoea worldwide. The consumption of contaminated chicken meat is the most common route to infection, but how this microaerophilic pathogen survives within the supermarket environment remains unclear. There is increasing concern surrounding the rising level of fluoroquinolone resistance observed in Campylobacter. We have previously demonstrated a link between fluoroquinolone resistance and increased survival and virulence within a fluoroquinolone resistant C. jejuni mutant model. In this current study a panel of fresh isolates (abattoir chicken, supermarket chicken and human) was established with the aim to assess the prevalence of fluoroquinolone resistance and investigate its impact on key phenotypes associated with the survival and virulence of this pathogen. Supermarket chicken isolates displayed the highest level of fluoroquinolone resistance (94%), while only 56% of abattoir chicken isolates and 44% of human isolates were found to be resistant. Fluoroquinolone resistance was also found to be associated with oxygen tolerance, as all isolates that showed medium or high level of resistance to ciprofloxacin were also oxygen tolerant. The phenotypes of isolate groups were also found to differ greatly. For example, supermarket isolates showed increased motility and the growth of human isolates at 37C was decreased. Variation in the ability of isolates to adhere to or invade HT29 cells was also observed, with supermarket isolates displaying the highest level of cell association. These results highlight the prevalence of fluoroquinolone resistance throughout the food chain, especially within the supermarket environment. The high level of fluoroquinolone resistance within the supermarket isolate group and the correlation between this resistance and oxygen tolerance supports previous data and suggests that the supermarket environment may be selecting for fluoroquinolone resistant strains within the food chain.

Presenting in Speaking session 4 - Survival and application