Liu Liyun, Qin Liyun, Hao Shuai, Lan Ruiting, Xu Baohong, Guo Yumei, Jiang Ruiping, Sun Hui, Chen Xiaoping, Lv Xinchao, Xu Jianguo, Zhao Chuan
State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang 050011, China.
Pathogens. 2020 Mar 6;9(3):195. doi: 10.3390/pathogens9030195.
spp are opportunistic human pathogens which can cause nosocomial infections, sporadic infections and outbreaks. In order to determine the genetic diversity, virulence properties and antimicrobial resistance profiles of spp, 128 Citrobacter isolates obtained from human diarrheal patients, foods and environment were assessed by multilocus sequence typing (MLST), antimicrobial susceptibility testing and adhesion and cytotoxicity testing to HEp-2 cells. The 128 Citrobacter isolates were typed into 123 sequence types (STs) of which 101 were novel STs, and these STs were divided into five lineages. Lineages I and II contained isolates; Lineage III contained all isolates, while Lineage IV and V contained isolates. Lineages II and V contained more adhesive and cytotoxic isolates than Lineages I, III, and IV. Fifty-one of the 128 isolates were found to be multidrug-resistant (MDR, ≥3) and mainly distributed in Lineages I, II, and III. The prevalence of quinolone resistance varied with Lineage III ( ) having the highest proportion of resistant isolates (52.6%), followed by Lineage I ( ) with 23.7%. Seven variants, including two new alleles (qnrB93 and qnrB94) were found with Lineage I being the main reservoir. In summary, highly cytotoxic MDR isolates from diarrheal patients may increase the risk of severe disease.
某些种属是机会性人类病原体，可引起医院感染、散发性感染和暴发。为了确定某些种属的遗传多样性、毒力特性和抗菌药物耐药谱，对从人类腹泻患者、食品和环境中分离得到的128株柠檬酸杆菌进行了多位点序列分型（MLST）、抗菌药物敏感性测试以及对HEp-2细胞的黏附及细胞毒性测试。128株柠檬酸杆菌被分型为123种序列型（STs），其中101种为新的STs，这些STs被分为五个谱系。谱系I和II包含某些分离株；谱系III包含所有某些分离株，而谱系IV和V包含某些分离株。谱系II和V比谱系I、III和IV包含更多具有黏附性和细胞毒性的分离株。128株分离株中有51株被发现具有多重耐药性（MDR，≥3种），主要分布在谱系I、II和III中。喹诺酮耐药性的流行率因谱系而异，谱系III（ ）耐药分离株比例最高（52.6%），其次是谱系I（ ），为23.7%。在谱系I中发现了7种变异体，包括两个新等位基因（qnrB93和qnrB94），谱系I是主要储存库。总之，腹泻患者中具有高细胞毒性的MDR分离株可能会增加患重病的风险。
