Yan Jing-Jou, Zheng Po-Xing, Wang Ming-Cheng, Tsai Shu-Huei, Wang Li-Rong, Wu Jiunn-Jong
Department of Pathology, College of Medicine, National Cheng Kung University, Tainan, Taiwan Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan
Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
J Clin Microbiol. 2015 Oct;53(10):3256-63. doi: 10.1128/JCM.01152-15. Epub 2015 Jul 29.
The OmpK36 porin plays a role in carbapenem resistance and may contribute to bacterial virulence in Klebsiella pneumoniae. This study aimed to investigate the characteristics of different groups of K. pneumoniae separated by ompK36 typing. Among 226 nonduplicate K. pneumoniae bloodstream isolates collected at a Taiwanese hospital in 2011, four ompK36 types, designated types A, B, C, and D, were identified by PCR in 61, 28, 100, and 36 isolates, respectively; 1 isolate was untypeable. Statistical analysis showed significantly higher rates of antimicrobial resistance (all tested antibiotics except meropenem), extended-spectrum β-lactamases or DHA-1 (47.5% together), Qnr-type quinolone resistance determinants (50.8%), and IncFIIA-type plasmids (49.2%) in group A than in others. Seventeen isolates were identified as belonging to 3 international high-risk clones (4 sequence type 11 [ST11], 10 ST15, and 3 ST147 isolates); all isolates but 1 ST15 isolate were classified in group A. The significant characteristics of group C were hypermucoviscosity (62.0%) and a higher virulence gene content. This group included all serotype K1 (n = 30), K2 (n = 25), and K5 (n = 3) isolates, 6 of 7 K57 isolates, all isolates of major clones associated with pyogenic liver abscesses (29 ST23, 11 ST65, 5 ST86, 7 ST373, and 1 ST375 isolates), and 16 (94.1%) of 17 isolates causing bacteremic liver abscesses. Twelve (42.9%) of the group B isolates were responsible for bacteremic biliary tract infections. Group D was predominant (83.3%) among 12 K20 isolates. This study suggests that most clinical K. pneumoniae isolates can be allocated into four groups with distinct characteristics based on ompK36 types.
外膜孔蛋白K36（OmpK36）在肺炎克雷伯菌对碳青霉烯类抗生素的耐药性中起作用，并且可能与细菌毒力有关。本研究旨在调查通过ompK36分型分离出的不同组肺炎克雷伯菌的特征。在2011年一家台湾医院收集的226株非重复肺炎克雷伯菌血流分离株中，通过聚合酶链反应（PCR）分别在61株、28株、100株和36株分离株中鉴定出四种ompK36类型，分别命名为A、B、C和D型；1株无法分型。统计分析显示，A组的抗菌药物耐药率（除美罗培南外的所有测试抗生素）、超广谱β-内酰胺酶或DHA-1（两者合计47.5%）、Qnr型喹诺酮耐药决定簇（50.8%）和IncFIIA型质粒（49.2%）的发生率显著高于其他组。17株分离株被鉴定属于3个国际高危克隆（4株序列型11 [ST11]、10株ST15和3株ST147分离株）；除1株ST15分离株外，所有分离株均归类于A组。C组的显著特征是高黏液性（62.0%）和较高的毒力基因含量。该组包括所有血清型K1（n = 30）、K2（n = 25）和K5（n = 3）分离株、7株K57分离株中的6株、与化脓性肝脓肿相关的主要克隆的所有分离株（29株ST23、11株ST65、5株ST86、7株ST373和1株ST375分离株）以及17株引起菌血症性肝脓肿的分离株中的16株（94.1%）。B组中有12株（42.9%）导致菌血症性胆道感染。D组在12株K20分离株中占主导地位（83.3%）。本研究表明，大多数临床肺炎克雷伯菌分离株可根据ompK36类型分为具有不同特征的四组。
