Zhao Shaohua, Mukherjee Sampa, Chen Yuansha, Li Cong, Young Shenia, Warren Melissa, Abbott Jason, Friedman Sharon, Kabera Claudine, Karlsson Maria, McDermott Patrick F
Division of Animal and Food Microbiology, Office of Research, Center for Veterinary Medicine, US Food and Drug Administration, Laurel, Maryland, USA
Division of Animal and Food Microbiology, Office of Research, Center for Veterinary Medicine, US Food and Drug Administration, Laurel, Maryland, USA.
J Antimicrob Chemother. 2015 May;70(5):1314-21. doi: 10.1093/jac/dkv001. Epub 2015 Feb 1.
To understand the molecular epidemiology of gentamicin-resistant Campylobacter and investigate aminoglycoside resistance mechanisms.
One-hundred-and-fifty-one gentamicin-resistant Campylobacter isolates from humans (n = 38 Campylobacter jejuni; n = 41, Campylobacter coli) and retail chickens (n = 72 C. coli), were screened for the presence of gentamicin resistance genes by PCR and subtyped using PFGE. A subset of the isolates (n = 41) was analysed using WGS.
Nine variants of gentamicin resistance genes were identified: aph(2″)-Ib, Ic, Ig, If, If1, If3, Ih, aac(6')-Ie/aph(2″)-Ia and aac(6')-Ie/aph(2″)-If2. The aph(2″)-Ib, Ic, If1, If3, Ih and aac(6')-Ie/aph(2″)-If2 variants were identified for the first time in Campylobacter. Human isolates showed more diverse aminoglycoside resistance genes than did retail chicken isolates, in which only aph(2″)-Ic and -Ig were identified. The aph(2″)-Ig gene was only gene shared by C. coli isolates from human (n = 27) and retail chicken (n = 69). These isolates displayed the same resistance profile and similar PFGE patterns, suggesting that contaminated retail chicken was probably the source of human C. coli infections. Human isolates were genetically diverse and generally more resistant than the retail chicken isolates. The most frequent co-resistance was to tetracycline (78/79, 98.7%), followed by ciprofloxacin/nalidixic acid (46/79, 58.2%), erythromycin and azithromycin (36/79, 45.6%), telithromycin (32/79, 40.5%) and clindamycin (18/79, 22.8%). All human and retail meat isolates were susceptible to florfenicol.
This study demonstrated that several new aminoglycoside resistance genes underlie the recent emergence of gentamicin-resistant Campylobacter, and that, in addition to contaminated retail chicken, other sources have also contributed to gentamicin-resistant Campylobacter infections in humans.
了解耐庆大霉素弯曲杆菌的分子流行病学，并研究氨基糖苷类耐药机制。
采用聚合酶链反应（PCR）筛选151株来自人类（空肠弯曲杆菌38株；结肠弯曲杆菌41株）和零售鸡肉（结肠弯曲杆菌72株）的耐庆大霉素弯曲杆菌分离株中庆大霉素耐药基因的存在情况，并使用脉冲场凝胶电泳（PFGE）进行亚型分析。对一部分分离株（41株）进行全基因组测序（WGS）分析。
鉴定出9种庆大霉素耐药基因变体：aph(2″)-Ib、Ic、Ig、If、If1、If3、Ih、aac(6')-Ie/aph(2″)-Ia和aac(6')-Ie/aph(2″)-If2。aph(2″)-Ib、Ic、If1、If3、Ih和aac(6')-Ie/aph(2″)-If2变体首次在弯曲杆菌中被鉴定出来。人类分离株显示出比零售鸡肉分离株更多样化的氨基糖苷类耐药基因，零售鸡肉分离株中仅鉴定出aph(2″)-Ic和-Ig。aph(2″)-Ig基因是人类（27株）和零售鸡肉（69株）来源的结肠弯曲杆菌分离株中唯一共有的基因。这些分离株表现出相同的耐药谱和相似的PFGE模式，表明受污染的零售鸡肉可能是人类结肠弯曲杆菌感染的来源。人类分离株在基因上具有多样性，且通常比零售鸡肉分离株耐药性更强。最常见的共同耐药是对四环素（78/79，98.7%），其次是环丙沙星/萘啶酸（46/79，58.2%）、红霉素和阿奇霉素（36/79，45.6%）、泰利霉素（32/79，40.5%）和克林霉素（18/79，22.8%）。所有人类和零售肉类分离株对氟苯尼考敏感。
本研究表明，几种新的氨基糖苷类耐药基因是近期耐庆大霉素弯曲杆菌出现的基础，并且除了受污染的零售鸡肉外，其他来源也导致了人类耐庆大霉素弯曲杆菌感染。
