IMP-4 and OXA β-lactamases in Acinetobacter baumannii from Singapore
IMP-4 and OXA β-lactamases in Acinetobacter baumannii from Singapore
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DOI：
10.1093/jac/dkl544
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发表时间：
2007-04-01
影响因子：
5.2
通讯作者：
Zhao, Yi
中科院分区：
文献类型：
--
作者：
Koh, Tse Hsien;Sng, Li-Hwei;Zhao, Yi
目的：比较两个时间段鲍曼不动杆菌碳青霉烯酶基因的检出率。方法：对114株亚胺培南耐药株进行研究。鲍曼不动杆菌在两个5个月的时间段内（1996年和2001年）收集。使用PCR筛选通过平板生物测定显示碳青霉烯酶活性的分离株的碳青霉烯酶基因。在用Apal消化后，对来自携带碳青霉烯酶基因的菌株的染色体DNA进行PFGE。结果：耐亚胺培南的A.鲍曼不动杆菌感染率从1996年的1.1/1000上升到2001年的2.3/1000。然而，产碳青霉烯酶的A.与1996年（每1 000名住院病人中0.5人）相比，2001年（每1 000名住院病人中0.8人）鲍曼不动杆菌感染率仅略有上升。在44株具有碳青霉烯酶活性的分离株中，4株分离株携带bla（IMP-4），5株携带bla（OXA-58），40株携带bla（OXA-23）。此外，大多数分离株携带bla（OXA-51）型β-内酰胺酶基因。所有携带bla（IMP-4）的菌株也携带bla（OXA-58）和bla（PSE-1），但不携带bla（OXA-51）型β-内酰胺酶基因。对7株新分离的敏感A.鲍曼不动杆菌显示仅存在bla（OXA-51）型β-内酰胺酶基因。共发现5个新的bla（OXA-51）型β-内酰胺酶基因（bla（OXA-88，-91，-93，-94）和（-95））和1个新的bla（OXA-58）型β-内酰胺酶基因（bla（OXA-96））。在A.新加坡的鲍曼不动杆菌。在我们的研究中发现的最常见的碳青霉烯酶基因是bla（OXA-23）。
Objective: To compare the incidence of carbapenemase genes in Acinetobacter baumannii between two time periods. Methods: We studied 114 isolates of imipenem-resistant A. baumannii collected over two 5 month periods (in 1996 and 2001). Isolates showing carbapenemase activity by plate bioassay were screened for carbapenemase genes using PCR. Chromosomal DNA from strains carrying carbapenemase genes was subjected to PFGE after digestion with Apal. Results: The incidence of imipenem-resistant A. baumannii in our hospital rose from 1.1 per 1000 admissions in 1996 to 2.3 per, 1000 admissions in 2001. However, the number of carbapenemase-producing A. baumannii rose, only slightly in 2001 (0.8 per 1000 admissions) compared to 1996 (0.5 per 1000 admissions). Of 44 isolates with carbapenemase activity, 4 isolates carried bla(IMP-4), 5 carried bla(OXA-58), and 40 carried bla(OXA-23). In addition, most isolates carried a bla(OXA-51)-type beta-lactamase gene. All strains with bla(IMP-4), also carried bla(OXA-58) and bla(PSE-1), but not bla(OXA-51)-type beta-lactamase genes. PCR analysis repeated on seven recent isolates of susceptible A. baumannii showed only the presence of bla(OXA-51)-type beta-lactamase genes. A total of five novel bla(OXA-51)-type beta-lactamase genes (bla(OXA-88,-91,-93,-94), and (-95)) and one new bla(OXA-58)-type beta-lactamase gene (bla(OXA-96)) were found. Conclusions: The incidence of carbapenemase genes did not vary significantly between the two study periods. There is a wide diversity of OXA genes in A. baumannii in Singapore. The most common carbapenemase gene found in our study was bla(OXA-23).