Sidjabat Hanna E, Townell Nicola, Nimmo Graeme R, George Narelle M, Robson Jennifer, Vohra Renu, Davis Louise, Heney Claire, Paterson David L
University of Queensland, UQ Centre for Clinical Research, Brisbane, Queensland, Australia
Pathology Queensland, Brisbane, Queensland, Australia.
Antimicrob Agents Chemother. 2015 Jul;59(7):4059-66. doi: 10.1128/AAC.04378-14. Epub 2015 Apr 27.
The prevalence of carbapenemase-producing Enterobacteriaceae (CPE) has been increasing worldwide. blaIMP has been reported to be the predominant carbapenemase-encoding gene within Enterobacteriaceae in Australia. However, there are limited data currently available on CPE from Queensland, Australia. A total of 58 CPE isolates were isolated between July 2009 and March 2014 from Queensland hospitals. The clonality of isolates was determined by Diversilab repetitive sequence-based PCR. The isolates were investigated for the resistance mechanisms carbapenemase, extended-spectrum β-lactamase, and AmpC β-lactamase and for aminoglycoside resistance and plasmid-mediated quinolone resistance genes by PCR. The plasmid types associated with carbapenemase-encoding genes were characterized. The majority of the CPE were Enterobacter cloacae (n = 29). The majority of Queensland CPE isolates were IMP producers and comprised 11 species (n = 48). Nine NDM-producing Enterobacteriaceae were identified. One NDM-producing Klebsiella pneumoniae isolate coproduced OXA-48. One K. pneumoniae isolate was an OXA-181 producer. The incidence of IMP producers increased significantly in 2013. blaIMP-4 was found in all IMP-producing isolates. blaTEM, qnrB, and aacA4 were common among IMP-4 producers. The HI2 (67%) and L/M (21%) replicons were associated with blaIMP-4. All HI2 plasmids were of sequence type 1 (ST1). All but one of the NDM producers possessed blaCTX-M-15. The 16S rRNA methylase genes found among NDM producers were armA, rmtB, rmtC, and rmtF. The substantial increase in the prevalence of CPE in Queensland has been associated mainly with the emergence E. cloacae strains possessing HI2 plasmids carrying blaIMP-4 over the past 2 years. The importation of NDM producers and/or OXA-48-like producers in patients also contributed to the increased emergence of CPE.
产碳青霉烯酶肠杆菌科细菌（CPE）在全球范围内的流行率一直在上升。据报道，blaIMP是澳大利亚肠杆菌科细菌中主要的碳青霉烯酶编码基因。然而，目前来自澳大利亚昆士兰州的CPE数据有限。2009年7月至2014年3月期间，从昆士兰州医院共分离出58株CPE菌株。通过基于重复序列的Diversilab PCR确定分离株的克隆性。通过PCR研究分离株的碳青霉烯酶、超广谱β-内酰胺酶和AmpCβ-内酰胺酶耐药机制以及氨基糖苷类耐药性和质粒介导的喹诺酮耐药基因。对与碳青霉烯酶编码基因相关的质粒类型进行了表征。大多数CPE为阴沟肠杆菌（n = 29）。昆士兰州的大多数CPE分离株是IMP生产者，包括11个菌种（n = 48）。鉴定出9株产NDM的肠杆菌科细菌。一株产NDM的肺炎克雷伯菌分离株同时产生OXA-48。一株肺炎克雷伯菌分离株是OXA-181生产者。2013年IMP生产者的发生率显著增加。在所有产IMP的分离株中均发现blaIMP-4。blaTEM、qnrB和aacA4在产IMP-4的菌株中很常见。HI2（67%）和L/M（21%）复制子与blaIMP-4相关。所有HI2质粒均为序列类型1（ST1）。除一株外，所有产NDM的菌株均具有blaCTX-M-15。在产NDM的菌株中发现的16S rRNA甲基化酶基因是armA、rmtB、rmtC和rmtF。在过去2年中，昆士兰州CPE流行率的大幅上升主要与携带blaIMP-4的HI2质粒的阴沟肠杆菌菌株的出现有关。患者中产NDM和/或OXA-48样生产者的输入也导致了CPE出现的增加。
