Abstract：
The rapid emergence of antimicrobial resistance (AMR) in Campylobacter has reinforced its status as a foodborne pathogen of significant public health concern. Resistant Campylobacter is typically transferred to humans via the consumption of contaminated animal products, particularly poultry. The genes associated with antimicrobial resistance in Campylobacter spp. are poorly understood. To address this knowledge gap, we conducted a prevalence survey of AMR Campylobacter across 84 chicken farms in two districts of Bangladesh. Pooled cloacal swabs were collected from chickens and underwent bacteriological testing for Campylobacter spp. with PCR confirmation. Antimicrobial susceptibility was tested against 14 antibiotics by disk diffusion method, and 12 resistance genes were screened in Campylobacter-positive isolates using multiplex PCR. A total of 34 (40.5%) farms were Campylobacter-positive of which 73.5% of isolates were resistant to at least 10 antibiotics. The antimicrobial susceptibility results indicate a high level of resistance against streptomycin (97.1%), clindamycin (97.1%), ampicillin (94.1%), tetracycline (94.1%), erythromycin (91.2%), ciprofloxacin (88.2%), nalidixic acid (85.3%), and imipenem (82.4%), and comparatively a low frequency of resistance to chloramphenicol (47.1%), ceftazidime (44.1%), and colistin (35.3%). Multidrug-resistant (MDR) and extensively drug-resistant Campylobacter were identified in 97.1%, and 50% of isolates, respectively. Ten resistance genes were identified including blaTEM (in 97.1% of isolates), strA-strB (85.9%), tetA (70.6%), tetB (32.4%), qnrS (23.5%), blaCTX-M-1 (20.6%), qnrB (20.6%), blaSHV (8.8%), aadB (5.9%), and qnrA (2.9%). Our findings demonstrate that resistance to ampicillin, tetracycline, and ceftazidime in Campylobacter isolates was significantly (p ≤ 0.05) associated with the presence of blaTEM, tetA, and blaSHV genes, respectively. The high rates of AMR in Campylobacter isolates from our study are not surprising given the liberal use of antimicrobials and incomplete biosecurity provisions on farms. Of particular concern are resistance rates to those classes of antibiotics that should be reserved for human use (azithromycin, ciprofloxacin, and colistin). AMR was more prevalent in chicken farms that used multiple antibiotics, engaged in prophylactic treatment of the birds, and improperly disposed of antibiotic packages. The high prevalence of MDR in chicken-derived Campylobacter isolates from the different regions of our study reinforces the need for more prudent use of antimicrobial compounds in Bangladeshi chicken farms.
摘要：
弯曲杆菌中抗生素耐药性（AMR）的迅速出现增强了其作为重大公共卫生问题的食源性病原体的地位。抗性弯曲杆菌通常通过食用受污染的动物产品转移给人类，尤其是家禽。与弯曲杆菌耐药性相关的基因。知之甚少。为了解决这个知识差距，我们对孟加拉国两个地区84个养鸡场的AMR弯曲杆菌进行了患病率调查.从鸡中收集收集的泄殖腔拭子，并进行了弯曲杆菌属的细菌学测试。PCR确认。采用纸片扩散法对14种抗生素进行药敏试验,采用多重PCR方法对弯曲杆菌阳性分离株中的12个耐药基因进行了筛选。共有34个（40.5%）农场为弯曲杆菌阳性，其中73.5%的分离株对至少10种抗生素耐药。抗菌药物敏感性结果表明对链霉素的耐药性很高（97.1％），克林霉素（97.1%），氨苄青霉素（94.1%），四环素（94.1%），红霉素（91.2%），环丙沙星（88.2%），萘啶酸(85.3%),和亚胺培南(82.4%)，对氯霉素的抗性相对较低（47.1％），头孢他啶(44.1%),和粘菌素(35.3%)。多药耐药（MDR）和广泛耐药的弯曲杆菌在97.1％，50%的分离株，分别。确定了10个抗性基因，包括blaTEM（在97.1％的分离物中），strA-strB（85.9%），tetA（70.6%），tetB（32.4%），qnrS（23.5%），blaCTX-M-1（20.6%），qnrB（20.6%），blaSHV（8.8%），aadB(5.9%),和qnrA（2.9%）。我们的研究结果表明，对氨苄青霉素的耐药性，四环素,弯曲杆菌中头孢他啶与blaTEM的存在显着相关（p≤0.05），tetA,和blaSHV基因，分别。鉴于抗微生物剂的自由使用和农场的生物安全规定不完整，我们研究中的弯曲杆菌分离物中AMR的高比率并不令人惊讶。特别值得关注的是对那些应保留给人类使用的抗生素类别的耐药率（阿奇霉素，环丙沙星,和粘菌素）。AMR在使用多种抗生素的养鸡场中更为普遍，从事鸟类的预防性治疗，并不当处置抗生素包装。来自我们研究不同地区的鸡肉弯曲杆菌分离物中MDR的高患病率加强了在孟加拉国养鸡场中更谨慎使用抗菌化合物的必要性。
