French Agency for Food, Environmental and Occupational Health Safety (ANSES) , Mycoplasmology and Bacteriology Unit, Ploufragan, France .
Microb Drug Resist. 2012 Apr;18(2):101-8. doi: 10.1089/mdr.2011.0188. Epub 2012 Feb 10.
The aim of this study was to investigate the fitness of macrolide resistant Campylobacter coli and Campylobacter jejuni. The in vitro growth, the survival on food matrix, and the in vivo colonization of C. jejuni and C. coli susceptible isolates and their isogenic resistant mutants were studied. In vitro experiments demonstrated that macrolide resistance imposed a fitness cost when the susceptible strains and their isogenic resistant mutants were cultured in competition. When inoculated in food matrix, the resistant C. jejuni mutant was no longer detectable after 3 to 5 days but the susceptible strain remained detectable for over 18 days. No difference in survival in food matrix was observed between susceptible and resistant C. coli. When inoculated in vivo in chickens, the macrolide susceptible and resistant C. coli displayed similar levels of colonization, both in separated inoculations and during competitive assays. Strikingly, when mono-inoculated or co-inoculated into chickens, macrolide susceptible C. jejuni outcompeted the macrolide resistant population. However, a spontaneous mutant that evolved in vivo showed a colonization capacity similar to the susceptible strain. Our findings demonstrate the effect of macrolide resistance on the fitness of Campylobacter but suggest that evolved mutants may be as fit as susceptible strains.
本研究旨在探讨耐大环内酯类药物的空肠弯曲菌和结肠弯曲菌的适应性。研究了空肠弯曲菌和结肠弯曲菌敏感分离株及其同源耐药突变株的体外生长、在食物基质中的存活能力以及体内定植能力。体外实验表明，当敏感株及其同源耐药突变株在竞争培养时，大环内酯类耐药会产生适应性成本。当接种于食物基质中时，耐药的空肠弯曲菌突变株在 3 至 5 天后不再可检测到，但敏感株可在 18 天以上被检测到。敏感株和耐药株的空肠弯曲菌在食物基质中的存活能力没有差异。在鸡体内接种时，敏感和耐药的结肠弯曲菌均显示出相似的定植水平，无论是单独接种还是在竞争实验中。引人注目的是，当单接种或共同接种到鸡体内时，敏感的空肠弯曲菌可竞争性地排除耐药株。然而，体内自发产生的突变株显示出与敏感株相似的定植能力。我们的研究结果表明了大环内酯类耐药对弯曲菌适应性的影响，但表明进化而来的突变株可能与敏感株一样具有适应性。
