铜绿假单胞菌对多粘菌素B的耐药性研究

Study on polymyxin B resistance of Pseudomonas aeruginosa

目的 研究铜绿假单胞菌对多粘菌素B的耐药性。方法 应用K-B法检测135株铜绿假单胞菌临床分离株对多粘菌素B的耐药性，应用多底物．多抑制剂协同法检测、推测其耐药机制并分析其分布情况。结果 ①在本组135株菌耐药6株（6／135，4．4％），非多耐菌耐药3株（3／59，5．1％），多耐菌耐药3株（3／62，4．8％），RCPA，全耐药菌和无耐药菌。②RCPA和全耐菌耐药机制涉及各种碳青霉烯酶2株、外排泵10株和D2通道缺乏10株。结论 铜绿假单胞菌对多粘菌素B的耐药率低，不同耐药程度的菌株对多粘菌素B的耐药程度相似；多粘菌素B耐药机制独特，与目前主要的耐药机制关联不大，需进一步研究。

Objective To study polymyxin B resistance of Pseudomonas aeruginosa （PA）. Methods To detect the polymyxin B resistance of 135 strains of PA isolates with K-B testing, to detect the resistant mechanisms in the strains with multi disk-multi inhibitor synergy test （MDMIST）. Results ①In the 135 PA strains, the resistant rate is 4.4% （6 strains）, the resistant rate of unmulti- resistant strains is 5.1% （3 strains）, the resistant rate of multi- resistant strains is 4.8% （3 strains）, and no resistant strains in RCPA and pan-resistant strains. ②the resistant mechanisms in the RCPA and pan-resistant strains involve all kinds of carbapenemases （2 strains）, efflux system （10 strains）, D2 porin defect （10 strains）. Conclusion The resistant rate of polymyxin B to PA is low, the polymyxin B resistance of the strains with different resistant degree is the similar; the resistant mechanisms of polymyxin B is special and it has no relationship with the current mainly resistant mechanisms, it must be study further more in the future.