Ciprofloxacin Resistance inCampylobacter jejuniEvolves Rapidly in Chickens Treated with Fluoroquinolones

Abstract

Fluoroquinolones are commonly used to treat gastroenteritis caused by Campylobacter species. Domestically acquired fluoroquinolone-resistant Campylobacter infection has been documented recently in the United States. It has been proposed that the increase in resistance is due, in part, to the use of fluoroquinolones in poultry. In separate experiments, the effects of sarafloxacin and enrofloxacin treatment of Campylobacter jejuni-infected chickens on the development of ciprofloxacin resistance were measured. Fecal samples were collected before and after treatment and were cultured for C. jejuni. When enrofloxacin or sarafloxacin was used at US Food and Drug Administration-approved doses in broiler chickens, resistance developed rapidly and persisted in C. jejuni. MICs of ciprofloxacin increased from a base of 0.25 microg/mL to 32 microg/mL within the 5-day treatment time frame. These results show that the use of these drugs in chickens rapidly selects for resistant Campylobacter organisms and may result in less effective fluoroquinolone therapy for cases of human campylobacteriosis acquired from exposure to contaminated chicken.

Bile Salts Modulate Expression of the CmeABC Multidrug Efflux Pump inCampylobacter jejuni

“…Although the enhanced efflux itself cannot confer clinically relevant resistance to antibiotics, it may facilitate bacteria to better survive selection pressure and promote the emergence of antibiotic-resistant mutants via target gene mutations (e.g., gyrA mutations mediating fluoroquinolone resistance). This speculation is consistent with the observation that ciprofloxacin-resistant Campylobacter rapidly emerged in the intestinal tracts of chickens or humans treated with fluoroquinolone antimicrobials (25,29,45,52). However, direct evidence is still lacking for bile-mediated enhancement of antimicrobial resistance in vivo.…”

The Challenge of Regulating Agricultural Ceftiofur Use To Slow the Emergence of Resistance to Extended-Spectrum Cephalosporins

“…The mass application of therapeutic enrofloxacin to control mortality in broiler chickens may have resulted in the emergence and zoonotic food-borne transmission of fluoroquinolone-resistant Campylobacter jejuni in the early 2000s (11). While that application is now prohibited, veterinary enrofloxacin use is currently allowed in both cattle and swine but with label restrictions that prevent its mass application for disease control and require a diagnosis by a veterinarian.…”

Susceptibilities of Campylobacter jejuni Isolates from Germany to Ciprofloxacin, Moxifloxacin, Erythromycin, Clindamycin, and Tetracycline

“…Experimentally, supplementation of drinking water with enrofloxacin rapidly led to the induction of enrofloxacin and ciprofloxacin resistance of Campylobacter spp. in broilers (14,15). Fluoroquinolones have been licensed in Germany for use in cattle and swine since 1989 and in poultry since 1990.…”