Long-term dissemination of acquired AmpC β-lactamases among Klebsiella spp. and Escherichia coli in Portuguese clinical settings
Long-term dissemination of acquired AmpC β-lactamases among Klebsiella spp. and Escherichia coli in Portuguese clinical settings
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DOI：
10.1007/s10096-013-1983-9
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发表时间：
2014-04-01
影响因子：
4.5
通讯作者：
Peixe, L.
中科院分区：
文献类型：
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作者：
Freitas, F.;Machado, E.;Peixe, L.
我们调查了葡萄牙临床分离的缺乏可诱导的染色体AmpC酶的肠杆菌科细菌中编码获得性AmpC酶(QAmpC)的基因的出现、多样性和分子流行病学。对7年间(2002-2008年)从4家医院和3家社区实验室获得的675株对广谱头孢菌素不敏感的菌株进行了分析。用表型标准、聚合酶链式反应(PCR)和测序分析qAmpC编码基因的存在。按标准程序进行细菌鉴定、药敏试验、接合试验和克隆分析。50%(50/100；41株肺炎克雷伯菌、5株大肠埃希菌、4株催产克雷伯菌)中存在bla(QAmpC)基因。在这些物种中检测到的DHA-1是最常见的qAmpC(94%，47/50)，自2003年以来在不同机构的整个研究期间都被确认。尽管观察到了高度的克隆多样性，但三株产DHA-1的克雷伯氏菌。克隆被发现的频率更高。在B1-E中检出CMY-2(6%，3/50)。Coli克隆。接合转移仅在1株(2%)CMY-2产生菌中观察到。大多数qAmpC产生者(94%，47/50)共表达SHV型和/或OXA-1或CTX-M-32超广谱β-内酰胺酶(ESBL S)。据作者所知，这是第一次描述产生qAmpC的肠杆菌科细菌在葡萄牙临床环境中的分子流行病学和长期传播，突显了葡萄牙头孢菌素耐药性向更复杂的流行病学情况的演变。
We investigated the occurrence, diversity and molecular epidemiology of genes coding for acquired AmpC beta-lactamases (qAmpC) among clinical isolates of Enterobacteriaceae lacking inducible chromosomal AmpCs in Portugal. A total of 675 isolates non-susceptible to broad-spectrum cephalosporins obtained from four hospitals and three community laboratories during a 7-year period (2002-2008) were analysed. The presence of genes coding for qAmpC was investigated by phenotypic criteria, polymerase chain reaction (PCR) and sequencing. Bacterial identification, antibiotic susceptibility testing, conjugation assays and clonal analysis were performed by standard procedures. The presence of bla (qAmpC) genes was detected in 50 % (50/100; 41 Klebsiella pneumoniae, 5 Escherichia coli, 4 Klebsiella oxytoca) of the presumptive qAmpC producers. DHA-1, detected in those species, was the most prevalent qAmpC (94 %, 47/50), being identified since 2003 and throughout the studied period in different institutions. Despite the high clonal diversity observed, three DHA-1-producing Klebsiella spp. clones were more frequently identified. CMY-2 (6 %, 3/50) was observed in B1-E. coli clones. Conjugative transfer was only observed in one (2 %) CMY-2-producing isolate. Most qAmpC producers (94 %, 47/50) co-expressed SHV-type and/or OXA-1 or CTX-M-32 extended-spectrum beta-lactamases (ESBLs). To the authors' knowledge, this is the first description of the molecular epidemiology and the long-term dissemination of qAmpC-producing Enterobacteriaceae in Portuguese clinical settings, highlighting an evolution towards a more complex epidemiological situation regarding cephalosporin resistance in Portugal.