产超广谱β-内酰胺酶AmpC细菌感染及耐药特性

Produing extended-spectrum β-lactamases and AmpCβ-lactamases strains: detection infection and resistance

[目的]了解医院内产超广谱β-内酰胺酶(ESBLs)和高产AmpC细菌感染和耐药特性。[方法]三维试验检测高产AmpC细菌、双纸片协同试验检测产ESBLs菌。Kirby-Bauer法测定药物敏感试验,回顾患者临床资料及使用抗生素情况。[结果]高产AmpC细菌在阴沟肠杆菌、肺炎克雷伯菌和大肠埃希菌分别为12.8%(11/89)、4.1%(7/170)和2.6%(5/190);产ESBLs菌分别为42.7%(38/89),肺炎克雷伯菌31.7%(54/170),大肠埃希菌27.3%(52/190),其中同时产两种酶为6株。高产AmpC和产ESBLs菌对三代头孢菌素,氨曲南的耐药性明显高于非产酶菌,对泰能均敏感。前者对四代头孢敏感但对酶抑制剂耐药。高产AmpC和产ESBLs菌感染与使用三代头孢有关。[结论]高产AmpC和产ESBLs是临床G-菌耐药的重要机制,其产生与使用三代头孢有关。

[ Objective] To investigate the infecting cause and antibiotic resistanceof producing extended- spectrum β- lactamases （ESBLs）and AmpCβ- lactamases bacteria in hospital. [ Methods] Producing ESBLs bacteria and AmpCβ - lactamases bacteria were detected by double- disk synergy and three - dimensional tests respectively. The antibiotic Susceptibility test was assayed by Kirby - Bauer. [Results] The incidence of AmpC- lactamases in E. Colacae. K.pneumoniae and E.coli was 12.8%（11/89）,4.1%（7/ 170） and 2.6%（5/190）respectively. The incidence of ESBLs in of E. Colacae. K. pneumoniae and E. coli was 42.7% （38/89）, 31.7 % （54/170） and 27.3% （52/190） respectively. AmpCβ-lactamases combined with ESBLs producing strains were found in 6 strains. Most producing ESBLs bacteria came from the patients treated with the third- generation cephalosporins. The resistance for cephalosporins and Aztreonarn in producing ESBLs and AmpCβ- lactamases strains was significantly higher than that of no producing ESBLs. The infection caused by producing ESBLs bacteria was sturbborn and ready to relapse. [ Conclusion] The production of ES- BLs, AmpCβ- lactamases strains were related with using the third- generation cephalosporins. And they lay the sasis of critical mechanism of Gram - negative bacteria, s drug - resistance.