Avison M B, von Heldreich C J, Higgins C S, Bennett P M, Walsh T R
Bristol Centre for Antimicrobial Research and Evaluation (BCARE), Department of Pathology and Microbiology, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK.
J Antimicrob Chemother. 2000 Dec;46(6):879-84. doi: 10.1093/jac/46.6.879.
A constitutively expressed beta-lactamase gene from a clinical isolate of Stenotrophomonas maltophilia, J675Ia, has been cloned. Its DNA sequence is almost identical to that of bla(TEM2) (one nucleotide change) and the expressed enzyme is a Bush type 2a penicillinase with an amino acid sequence identical to that of TEM-2. The bla(TEM) gene was present within a novel Tn1/Tn3-type transposon in the genome of isolate J675Ia and the transposon was able to mobilize bla(TEM) on to the broad host-range conjugative plasmid, R388. When transferred to an Escherichia coli recipient, R388::Tn conferred high-level ampicillin resistance. This represents the first identification of a TEM beta-lactamase in S. maltophilia and the first evidence that this important clinical pathogen is able to act as a reservoir for mobile beta-lactamase genes in the hospital environment.
一株嗜麦芽窄食单胞菌临床分离株J675Ia中组成型表达的β-内酰胺酶基因已被克隆。其DNA序列与bla(TEM2)几乎相同（仅一个核苷酸变化），表达的酶是一种Bush 2a型青霉素酶，氨基酸序列与TEM-2相同。bla(TEM)基因存在于分离株J675Ia基因组中的一个新型Tn1/Tn3型转座子内，该转座子能够将bla(TEM)转移到广泛宿主范围的接合质粒R388上。当转移到大肠杆菌受体中时，R388::Tn赋予高水平的氨苄青霉素抗性。这是嗜麦芽窄食单胞菌中首次鉴定出TEMβ-内酰胺酶，也是该重要临床病原体能够在医院环境中作为可移动β-内酰胺酶基因储存库的首个证据。
