4种非发酵糖革兰阴性杆菌β-内酰胺酶基因研究

β-Lactamase Genes in Four Kinds of Nonfermenting Gram-negative Bacilli

目的分析解放军第98医院临床分离的4种非发酵糖革兰阴性杆菌中β-内酰胺酶基因存在状况。方法从临床分离鲍氏不动杆菌60株、铜绿假单胞菌30株、嗜麦芽寡养单胞菌19株和黄杆菌属15株,采用PCR及序列分析的方法分析9种(群)β-内酰胺酶基因TEM、SHV、OXA、CTX-M群、PER、VEB、IMP、VIM、GES。结果鲍氏不动杆菌和铜绿假单胞菌中TEM基因阳性率分别为100.0%和66.7%;鲍氏不动杆菌有18株(30.0%)SHV阳性,17株为SHV-12型ESBLs(GenBank登录号:AY259163),另1株为一种新亚型,被命名为SHV-48;铜绿假单胞菌有1株(3.3%)OXA阳性,为OXA-10型ESBLs;其余基因均阴性。结论我院非发酵糖革兰阴性杆菌中至少存在4种β-内酰胺酶基因,基因型分别为TEM-1、SHV-12、SHV-48和OXA-10。

OBJECTIVE To investigate the β-lactamase genes in 4 kinds of nonfermenting Gram-negative bacilli isolated from the 98th Hospital of PLA. METHODS Sixty strains of Acinetobacter baumannii, 30 strains of Pseudomonas aeruginosa, 19 strains of Stenotrophomonas maltophilia, and 15 strains of Flavobacterium were isolated from hospitalized patients. Nine kinds of β-lactamases genes of TEM, SHV, OXA, CTX-M, PER, VEB, IMP,VIM and GES were analyzed by PCR and verified by DNA sequencing. RESULTS In A. baumannii and P. aeruginosa, the positive rates of gene of TEM were 100. 0% and 66.70%, respectively. SHV gene was positive in 18 of 60 strains of A. baumannii tested, 17 of which were SHV-12 subtype ESBLs. The other was a new SHV type β-lactamase nominated SHV-48. OXA gene was positive in 1 of 30 strains of P. aeruginosa tested, it was an OXA-10 subtype ESBLs. But the rest of genes were all negative. CONCLUSIONS There exist 4 kinds of β-lactamase genes at least in nonfermenting Gram-negative bacilli including TEM-1, SHV-12, SHV-48, and OXA-10.