Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, P. R. China.
Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
Int J Food Microbiol. 2014 Jul 2;181:77-84. doi: 10.1016/j.ijfoodmicro.2014.04.023. Epub 2014 Apr 28.
This study was conducted to determine the prevalence and distribution of Campylobacter species along a broiler production chain from farm to retail, and to evaluate the antimicrobial resistance profile of Campylobacter isolates. A total of 259 Campylobacter isolates (C. jejuni n=106, C. coli n=153) were isolated from broiler ceca samples (72.5%, 103/142), broiler carcasses (34.1%, 46/135), and retail broiler meat (31.3%, 40/128) samples collected in Shanghai, China. Minimal inhibitory concentrations of six antimicrobials were determined using the agar dilution method. High prevalence of resistance to ciprofloxacin (C. jejuni: 99.1%;C. coli: 100%) and tetracycline (C. jejuni: 100%;C. coli: 98.7%) was detected among the C. jejuni and C. coli isolates. The vast majority of C. coli were resistant to clindamycin (92.2%), gentamicin (95.4%), and erythromycin (94.1%), but only 25.5%, 53.8%, and 16.0% of C. jejuni exhibited resistance to these three antimicrobials, respectively. In contrast, the prevalence of florfenicol resistance in C. jejuni (37.7%) was significantly higher than that in C. coli (7.8%) (P<0.05). It is noteworthy that all Campylobacter isolates were resistant to one or more antimicrobials, and 71.7% of C. jejuni and 98.0% of C. coli isolates exhibited multi-drug resistance (resistant to three or more antimicrobials). Fifty-five C. jejuni and sixty C. coli isolates, selected from different production stages, species, and antimicrobial resistance patterns, were analyzed by pulsed field gel electrophoresis (PFGE), among which 15 unique PFGE patterns (PFGE patterns represented by a single strain) and 31 clusters (PFGE patterns represented by multiple strains) were detected. Furthermore, nearly all of the PFGE patterns of the Campylobacter strains isolated from retail broiler meats overlapped with those of the strains from ceca and slaughterhouse carcasses. Together, these findings revealed the high prevalence of Campylobacter species in a broiler chicken production chain, and the concerning situation of antimicrobial resistance in Campylobacter species. The findings also indicated that Campylobacter isolates from retail broiler meats were associated with fecal contamination in the slaughterhouse, underlying the need for improved measures for reducing carcass contamination in slaughter plants.
本研究旨在确定从农场到零售的肉鸡生产链中弯曲菌属的流行率和分布，并评估弯曲菌分离株的抗菌药物耐药谱。共从中国上海采集的肉鸡盲肠样本（72.5%，103/142）、肉鸡胴体（34.1%，46/135）和零售鸡肉样本（31.3%，40/128）中分离出 259 株弯曲菌（空肠弯曲菌 n=106，大肠弯曲菌 n=153）。采用琼脂稀释法测定了 6 种抗菌药物的最小抑菌浓度。空肠弯曲菌（99.1%；C. coli：100%）和四环素（C. jejuni：100%；C. coli：98.7%）对环丙沙星和四环素的耐药率均较高。绝大多数大肠弯曲菌对克林霉素（92.2%）、庆大霉素（95.4%）和红霉素（94.1%）耐药，但仅有 25.5%、53.8%和 16.0%的空肠弯曲菌分别对这三种抗菌药物耐药。相比之下，氟苯尼考在空肠弯曲菌（37.7%）中的耐药率明显高于大肠弯曲菌（7.8%）（P<0.05）。值得注意的是，所有的弯曲菌分离株都对一种或多种抗菌药物耐药，71.7%的空肠弯曲菌和 98.0%的大肠弯曲菌分离株表现出多药耐药（对三种或更多种抗菌药物耐药）。从不同生产阶段、种类和抗菌药物耐药模式中选择了 55 株空肠弯曲菌和 60 株大肠弯曲菌进行脉冲场凝胶电泳（PFGE）分析，其中检测到 15 种独特的 PFGE 模式（由单个菌株代表的 PFGE 模式）和 31 个聚类（由多个菌株代表的 PFGE 模式）。此外，从零售鸡肉中分离出的弯曲菌菌株的 PFGE 模式与盲肠和屠宰场胴体中分离出的菌株的 PFGE 模式几乎完全重叠。综上所述，这些研究结果揭示了肉鸡生产链中弯曲菌属的高流行率和弯曲菌属对抗菌药物的耐药情况。研究结果还表明，零售鸡肉中的弯曲菌分离株与屠宰场粪便污染有关，这需要改进屠宰场减少胴体污染的措施。
