title: Emergence of multidrug-resistant Campylobacter species isolates with a horizontally acquired rRNA methylase.
abstract: Antibiotic-resistant Campylobacter constitutes a serious threat to public health, and resistance to macrolides is of particular concern, as this class of antibiotics is the drug of choice for clinical therapy of campylobacteriosis. Very recently, a horizontally transferrable macrolide resistance mediated by the rRNA methylase gene erm(B) was reported in a Campylobacter coli isolate, but little is known about the dissemination of erm(B) among Campylobacter isolates and the association of erm(B)-carrying isolates with clinical disease. To address this question and facilitate the control of antibiotic-resistant Campylobacter, we determined the distribution of erm(B) in 1,554 C. coli and Campylobacter jejuni isolates derived from food-producing animals and clinically confirmed human diarrheal cases. The results revealed that 58 of the examined isolates harbored erm(B) and exhibited high-level resistance to macrolides, and most were recent isolates, derived in 2011-2012. In addition, the erm(B)-positive isolates were all resistant to fluoroquinolones, another clinically important antibiotic used for treating campylobacteriosis. The erm(B) gene is found to be associated with chromosomal multidrug resistance genomic islands (MDRGIs) of Gram-positive origin or with plasmids of various sizes. All MDRGIs were transferrable to macrolide-susceptible C. jejuni by natural transformation under laboratory conditions. Molecular typing of the erm(B)-carrying isolates by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) identified diverse genotypes and outbreak-associated diarrheal isolates. Molecular typing also suggested zoonotic transmission of erm(B)-positive Campylobacter. These findings reveal an emerging and alarming trend of dissemination of erm(B) and MDRGIs in Campylobacter and underscore the need for heightened efforts to control their further spread.
authors: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing, China.
authors: Yang
authors: Y
authors: Wang
authors: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
authors: Maojun
authors: M
authors: Zhang
authors: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing, China.
authors: Fengru
authors: F
authors: Deng
authors: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors: Zhangqi
authors: Z
authors: Shen
authors: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing, China.
authors: Congming
authors: C
authors: Wu
authors: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
authors: Jianzhong
authors: J
authors: Zhang
authors: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA sjz@cau.edu.cn zhang123@iastate.edu.
authors: Qijing
authors: Q
authors: Zhang
authors: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing, China sjz@cau.edu.cn zhang123@iastate.edu.
authors: Jianzhong
authors: J
authors: Shen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002169:Campylobacter Infections / Q000188:drug therapy; D016123:Campylobacter jejuni / Q000187:drug effects / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics*; D024841:Fluoroquinolones / Q000494:pharmacology; D044404:Genomic Islands / Q000235:genetics; D006801:Humans; D018942:Macrolides / Q000494:pharmacology; D008780:Methyltransferases / Q000235:genetics*; D008826:Microbial Sensitivity Tests / Q000379:methods; D058885:Multilocus Sequence Typing / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D018942:Macrolides; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase