肝移植术后细菌性感染的病原学特征

Pathogenic characters of infected bacteria after liver transplantation

目的:分析肝移植术后感染的主要病原菌及病原菌的耐药特征。方法:分析肝移植术后感染的主要病原菌,运用三维试验检测主要革兰阴性杆菌的超广谱β-内酰胺酶(extended-spectrumβ-lactamase,ESBLs)、AmpC酶等产生情况与变化,以头孢硝基噻吩显色法、琼脂稀释法检测肠球菌的β-内酰胺酶和Van基因。结果:肝移植术后感染主要病原菌为粪肠球菌(15.0%)、阴沟肠杆菌(13.9%)、真菌(13.3%)、大肠杆菌(10.7%)。阴沟肠杆菌和大肠杆菌的ESBLs酶检出率分别为32.4%和36.8%;AmpC酶的检出率为33.8%和10.5%,粪肠球菌和屎肠球菌的Van基因检出率分别是VanA7.5%和11.1%,VanB3.8%和7.4%,VanC1.3%和0。结论:肝移植术后以肠源性感染为主,产ESBLs与AmpC酶是肝移植术后革兰阴性杆菌耐药的主要机制,耐万古霉素的肠球菌在肝移植术后的检出率增高应引起临床重视。

Objective To analyze the main pathogens of infection after the liver transplantation and their antibiotic resistant patterns. Methods The main pathogens of infection after the liver transplantation were retrospectively analyzed. Using 3-dimensional tests, ESBLs （extended-spectrum β-1actamase） , and AmpC were detected among the Gram negative bacilli. β-Lactamase and Van gene in Enterococcus were determined by the standard agar dilution susceptibility tests and Nitrocefin respectively. Resuits The main infected strains were Enterococcus faecalis （15.0%）, Enterobacter cloacae （13.9%）, fungus （13.3%）, and Escherichia coli（10.7%） after the liver transplantation. Among them,32.4% of Enterobacter cloacae and 36.8% of Escherichia coli produced ESBLs; 33.8% of Enterobacter cloacae and 10.5% of Escherichia coll. produced AmpC β-1actamases. The detectable rate of VanA gene in Enterococcusfaecalis and Enterococcusfaeciurn was 7.5% and 11. 1% ; VanB was 3.8% and 7.4% ; VanC was 1.3% and 0,respectively. Conclusion The infection mainly occurs in the intestinal tract after the liver transplantation. The production of ESBLs and AmpC β-lactamases is the main mechanism of antibiotic resistance. The increased detectable rate of vancomycin-resistant Enterococcus should be paid attention to.