This study investigated occurrence and antimicrobial resistance profiles of Campylobacter spp. isolates in beef cattle on five cow–calf operations in South Africa. A total of 537 fecal samples from adult beef cattle (n = 435) and rectal swabs from calves (n = 102) were screened for Campylobacter jejuni, Campylobacter coli, and Campylobacter upsaliensis by culture and polymerase chain reaction. Furthermore, 86 Campylobacter spp. isolates including 46 C. jejuni, 24 C. coli, and 16 C. upsaliensis were tested for antimicrobial resistance against a panel of 9 antimicrobials. Overall, Campylobacter spp. was detected in 29.7% of cattle. Among the 158 Campylobacter spp.-positive cattle, 61.8% carried C. jejuni, 25% carried C. coli, and 10% carried C. upsaliensis. Five animals (3.1%) had mixed infections: three cows carried C. jejuni and C. coli concurrently, one cow had both C. jejuni and C. upsaliensis, and one cow harbored C. coli and C. upsaliensis. Antimicrobial resistance profiling among 86 Campylobacter spp. isolates revealed that 52.3% of the isolates were resistant to one or more antimicrobials. Antimicrobial resistance was observed in 46.7% of C. jejuni isolates, 35.6% of C. coli, and 17.8% of C. upsaliensis. Thirty-six percent of isolates were resistant to clindamycin, 19.7% to nalidixic acid, 18.6% to tetracycline, and 17.4% to erythromycin. Lower resistance rates were recorded for azithromycin (8.1%), florfenicol (3.4%), gentamicin (4.8%), and telithromycin and ciprofloxacin (5.8%). Multidrug resistance (MDR) was observed in 32.5% of isolates. Significantly higher levels of MDR were detected among C. jejuni (36.9%) and C. coli (33.3%) isolates in comparison to C. upsaliensis (18.7%). Two main multiresistance patterns were detected: nalidixic acid/clindamycin (17.8%) and tetracycline/clindamycin (14.2%). To the best of our knowledge, this is the first study which has shown that beef cattle on cow–calf operations in South Africa constitute an important reservoir and a potential source of clinically relevant and antimicrobial resistant Campylobacter spp. strains.

中文翻译：

---

南非牛犊作业中肉牛中空肠弯曲杆菌、大肠杆菌和乌萨里弯曲杆菌的发生率和抗菌素耐药性概况。

本研究调查了弯曲杆菌属的发生情况和抗菌素耐药性。在南非的五次牛犊操作中分离出肉牛。通过培养和聚合酶链反应，共对 537 份成年肉牛粪便样本 ( n  = 435) 和小牛的直肠拭子 ( n  = 102) 进行了空肠弯曲杆菌、大肠杆菌和普萨利弯曲杆菌的筛查。此外，86弯曲杆菌属。对包括 46 C. jejuni、24 C. coli和 16 C. upsaliensis在内的分离株进行了对一组 9 种抗菌剂的抗菌素耐药性测试。全面的，弯曲杆菌属 在 29.7% 的牛中检测到。在 158 头弯曲杆菌阳性牛中，61.8% 携带空肠弯曲杆菌，25% 携带大肠杆菌，10% 携带C. upsaliensis。五只动物（3.1％）的混合感染：三头奶牛进行空肠弯曲菌和C.大肠杆菌的同时，一头牛有两种空肠弯曲菌和C.乌普萨拉弯曲杆菌，和一对头牛窝藏C.大肠杆菌和C.乌普萨拉弯曲杆菌。86 种弯曲杆菌的耐药性分析属 分离株显示 52.3% 的分离株对一种或多种抗菌剂具有抗药性。在 46.7% 的空肠弯曲杆菌、35.6% 的大肠杆菌和 17.8% 的C. upsaliensis中观察到抗生素耐药性。36% 的分离株对克林霉素耐药，19.7% 对萘啶酸耐药，18.6% 对四环素耐药，17.4% 对红霉素耐药。阿奇霉素 (8.1%)、氟苯尼考 (3.4%)、庆大霉素 (4.8%) 以及泰利霉素和环丙沙星 (5.8%) 的耐药率较低。在 32.5% 的分离株中观察到多药耐药 (MDR)。与C. upsaliensis相比，在C. jejuni (36.9%) 和C. coli (33.3%) 分离物中检测到显着更高水平的 MDR(18.7%)。检测到两种主要的多重耐药模式：萘啶酸/克林霉素（17.8%）和四环素/克林霉素（14.2%）。据我们所知，这是第一项研究表明，南非牛犊操作中的肉牛构成了临床相关和抗微生物弯曲杆菌属的重要储存库和潜在来源。菌株。