多底物协同-拮抗法同时检测超广谱β-内酰胺酶和AmpC β-内酰胺酶

Multi-substrates synergy-antagonize test for detecting extented-spectrum β-lactamases and AmpC β-lactamases

目的 建立一种能同时检测超广谱 β 内酰胺酶 (ESBLs)和AmpCβ 内酰胺酶 (AmpCs)的简便、实用的方法。方法 应用“多底物协同 拮抗法”(MSSAT)检测 30株阴沟杆菌 (E .cl)和 4 2株不动杆菌 (Aci)的ESBLs和AmpCs。结果 MSSAT法检出各种ESBLs产酶株 5 3株 (E .cl2 5株 ,Aci 2 8株 ) ;各种AmpCs产酶株 5 2株 (E .cl 1 9株 ,Aci 33株 ) ,其中高诱导型 1 0株 (E .cl8株 ,Aci2株 ) ,部分去阻遏型 1 2株 (E .cl5株 ,Aci 7株 ) ,完全去阻遏型 30株 (E .cl 6株 ,Aci 2 4株 ) ;同时产ESBLs+AmpCs产酶株 37株 (E .cl 1 5株 ,Aci 2 2株 ) ,其中ESBLs +高诱导型 4株(均为E .cl) ,ESBLs+部分去阻遏型 6株 (E .cl 5株 ,Aci 1株 ) ,ESBLs+完全去阻遏型 2 7株 (E .cl 6株 ,Aci 2 1株 )。结论 MSSAT法能同时检测ESBLs+AmpCs及其不同型 ,且准确、简便、实用。在同时产ESBLs +AmpCs的细菌中 ,E .cl以产诱导型AmpCs为主 ,Aci则以产非诱导型AmpCs为主。同时产ESBLs+AmpCs的细菌大部分取自痰标本。

Objective To establish a simple and practical method for detecting extented spectrum β lactamases (ESBLs) and AmpC β lactamases (AmpCs) simultaneously. Methods Thirty strains of E.cloacae (E.cl) and 42 strains of Acinetobacter (Aci) were detected for ESBLs and AmpCs with multi substrates synergy antagonize test (MSSAT). Results Fifty three strains produced ESBLs (E.cl 25 strains, Aci 28); 52 strains produced AmpCs(E.cl 19, Aci 33). In the 52 AmpC producing strains, 10 produced highly inducible AmpCs (E.cl 8, Aci 2), 12 produced partially derepressed AmpCs (E.cl 5, Aci 7), and 30 produced stably derepressed AmpCs (E.cl 6, Aci 24); in the 37 strains producing ESBLs+AmpCs (E.cl 15, Aci 22), 4 strains produced ESBLs+highly inducible AmpCs (All were E.cl), 6 strains produced ESBLs+partially derepressed AmpCs (E.cl 5, Aci 1), and 27 strains produced ESBLs+stably derepressed AmpCs (E.cl 6, Aci 21). Conclusion MSSAT is a simple and practical method for the detection of ESBLs and AmpCs simultaneously; among bacteria producing both ESBLs and AmpCs, E.cl produces mainly inducible AmpCs, and Aci produces mainly non inducible AmpCs.