肠球菌氨基糖苷类高水平耐药基因的检测

Study on the mechanisms of high level aminoglycoside resistance in enterococcus

目的 调查肠球菌对高水平氨基糖苷类的耐药情况 ,并检测其耐药基因。方法 琼脂稀释法筛选对氨基糖苷类高水平耐药的肠球菌 ,PCR扩增 5种高耐药基因 :双功能酶AAC(6′) -APH(2″)的编码基因aac(6′) Ie -aph(2″) Ia ,磷酸转移酶APH(2″) Id、APH(2″) Ib的编码基因aph(2″) Id、aph(2″) Ib ,核苷酸转移酶ANT(6′)、ANT(3″) (9)的编码基因ant(6′) Ia和ant(3″) (9) ,并通过PCR产物的基因测序及寡核苷酸探针斑点杂交试验验证结果的可靠性。结果 粪肠球菌对氨基糖苷类高水平耐药率达 6 3% ,屎肠球菌达 84 %。 95 %以上庆大霉素高耐肠球菌 (HLGR)检测到aac(6′) Ie aph(2″) Ia、3株HLGR肠球菌检测到aph(2″) Id ,99%以上HLSR肠球菌检测到ant(6′) Ia。结论 肠球菌对氨基糖苷类高水平耐药十分普遍 ,双功能酶AAC(6′) -APH(2″)、核苷转移酶ANT(6′)分别介导了大多数肠球菌对庆大霉素、链霉素的耐药。

Objective Study on the mechanisms of high level aminoglycoside resistance in enterococcus Method High level gentamicin/streptomycin resistant enterococcus and middle level gentamicin resistant enterococcus were obtained by use of Agar Dilution Method Five high level resistant genes,aac(6′) Ie-aph(2″) Ia for bifunctional modifying enzyme AAC(6′)-APH(2″), aph(2″) Id for phosphotransferase APH(2″) Id, aph(2″) Ib for phosphotransferase APH(2″) Ib, ant(6′) Ia for nucleotidyltransferase ANT(6′) and ant(3″)(9) for nucleotidyltransferase ANT(3″)(9),were detected by PCR method, and confirmed by sequencing and dot blot Results 63% enterococcus faecalis and 84% enterococcus faecium were resistant to high level aminoglycoside aac(6′) Ie aph(2″) Ia was detected in more than 95% HLGR enterococcus aph(2″) Id was found in 3 strains of HLGR enterococcus 99% high level streptomycin resistance in enterococcus were caused by ant(6′) Ia Conclusion The resistance to high level aminoglycoside in enterococcus is very common Bifunctional modifying enzyme AAC(6′) APH(2″) and nucleotidyltransferase ANT(6′) Ia mediate most of the resistance to gentamicin and streptomycin,respectively