National Reference Laboratory of Antimicrobial Resistances, Department of Infectious Diseases, National Institute of Health Dr Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisbon, Portugal.
Int J Antimicrob Agents. 2012 Nov;40(5):398-403. doi: 10.1016/j.ijantimicag.2012.06.013. Epub 2012 Aug 11.
In this study, 116 multidrug-resistant Acinetobacter baumannii (MDR-Ab) isolates recovered in various regions of Portugal were studied. All isolates were non-susceptible to tigecycline; one isolate was also non-susceptible to colistin, making it a step closer to pandrug resistance. Among 72 isolates tested by PFGE, 98.6% carried bla(OXA-66), 1.4% bla(OXA-104), 77.8% bla(OXA-23), 23.6% bla(OXA-24), 18.1% bla(TEM-1) and 1.4% bla(CTX-M-15-like) genes. No OXA-58 or metallo-β-lactamase-encoding genes were detected. ISAba1 was found in 58/72 isolates (80.6%). Among these, ISAba1 was found upstream of bla(OXA-51-like) in 54 isolates. All but two of these isolates also carried ISAba1-bla(OXA-23), highlighting the coexistence of ISAba1-bla(OXA-51-like) and ISAba1-bla(OXA-23) genetic platforms, emphasising the importance of mobile genetic elements in the dissemination of carbapenem-hydrolysing class D β-lactamase genes. Tn2006-like and Tn2008-like, found within ST92 and ST118, may reflect either multiple genetic structures in the origin of bla(OXA-23) acquisition or interclonal complex evolution. These results indicate that there may exist different genetic origins for carbapenem resistance among MDR-Ab isolates. Six PFGE profiles were associated with three major sequence types, with ST118 (OXA-23- or OXA-24-producer) being widely disseminated since 2009. ST98 (described so far as endemic in Portugal) and ST92 (which co-existed with ST98 before 2009) appeared to have been gradually replaced by ST118. The new ST188 (OXA-104-producer) was detected for the first time in this country. Identification of an extensively drug-resistant ST118 and carbapenem-resistant ST92, ST98 and ST118 isolates, both in community and healthcare facilities, demonstrates the menace of A. baumannii-associated infections.
在这项研究中，研究了在葡萄牙不同地区回收的 116 株多药耐药鲍曼不动杆菌（MDR-Ab）分离株。所有分离株均对替加环素不敏感；有一株分离株也对黏菌素不敏感，使其更接近泛耐药性。在经过 PFGE 测试的 72 株分离株中，98.6%携带 bla(OXA-66)，1.4%携带 bla(OXA-104)，77.8%携带 bla(OXA-23)，23.6%携带 bla(OXA-24)，18.1%携带 bla(TEM-1)和 1.4%携带 bla(CTX-M-15-like)基因。未检测到 OXA-58 或金属β-内酰胺酶编码基因。发现 58/72 株（80.6%）分离株中存在 ISAba1。其中，ISAba1 在 54 株bla(OXA-51-like)上游发现。除了两个例外，这些分离株还携带 ISAba1-bla(OXA-23)，突出了 ISAba1-bla(OXA-51-like)和 ISAba1-bla(OXA-23)遗传平台的共存，强调了移动遗传元件在碳青霉烯水解类 Dβ-内酰胺酶基因传播中的重要性。Tn2006-like 和 Tn2008-like 存在于 ST92 和 ST118 中，可能反映了 bla(OXA-23)获得的起源存在不同的遗传结构，或者克隆间复杂进化的存在。这些结果表明，MDR-Ab 分离株中碳青霉烯耐药可能存在不同的遗传起源。6 种 PFGE 图谱与 3 种主要序列类型相关，ST118（OXA-23 或 OXA-24 生产者）自 2009 年以来广泛传播。ST98（迄今为止被描述为葡萄牙特有的）和 ST92（2009 年前与 ST98 共存）似乎已逐渐被 ST118 取代。新的 ST188（OXA-104 生产者）首次在该国被发现。在社区和医疗保健机构中，广泛耐药的 ST118 和耐碳青霉烯的 ST92、ST98 和 ST118 分离株的鉴定表明，与鲍曼不动杆菌相关的感染威胁很大。
