【摘要】 目的了解耐头孢西丁革兰阴性杆菌高产AmpC酶发生率及基因型分布和耐药性。方法对155株无重复耐头孢西丁革兰阴性杆菌,用酶提取物三维试验检测AmpC酶;ATB药敏试验板和K-B法检测产酶株的药物敏感性;质粒转化试验定位耐药基因;PCR扩增AmpC酶与ESBLs基因及其序列测定确定其基因型。结果高产AmpC酶的发生率为23.2%;自2株肺炎克雷伯菌和5株大肠埃希菌中检出DHA-1、CMY-2和CMY-22型AmpC酶,5株大肠埃希菌还分别同时携带TEM-1型广谱酶和TEM-144、CTX-M-27和CTX-M-14型超广谱β-内酰胺酶;CMY-22型和TEM-144型β-内酰胺酶是国内外首次报道,获得美国GenBank登录号分别为DQ256079和DQ256080。结论加强耐头孢西丁革兰阴性杆菌高产AmpC酶的监测,治疗相关菌感染以亚胺培南和美罗培南为首选;福州发现DHA-1、CMY-2和CMY-22型AmpC酶。更多还原

【Abstract】 OBJECTIVE To investigate the incidence rate of overexpressing AmpC β-lactamases in cefoxitin-resistant Gramnegative bacillus and the status of drug-resistance and genotype of plasmid-mediated AmpC β-lactamases. METHODS A total of 155 clinical isolates of nonrepetitive cefoxitin-resistant Gram-negative bacillus were detected by three-dimensional extract test for AmpC β-lactamases and by ATB STREP and KB methods for drug susceptibility.Drug resistant gene was positioned by plasmid transformation experiment.PCR for AmpC and ESBLs gene amplification and DNA sequencing were carried out for genotype of β-lactamases. RESULTS The incidence rate of overexpressing AmpC β-lactamases was 23.2%(36/155).DHA-1,CMY-2 and CMY-22 AmpC βlactamases were found in two strains of Klebsiella pneumoniae and five isolates of Escherichia coli.Furthermore,the five isolates of E.coli were also found to carry TEM-1,TEM-144,CTX-M-27 and CTX-M-14 enzyme respectively.TEM-144 and CMY-22 β-lactamases were the first reported in the world,GenBank accession number: DQ256080 and DQ256079.The resistance of strains with overexpressing AmpC β-lactamases was serious and multiple,but the sensitive rate to imipenem and meropenem was >87%. CONCLUSIONS The surveillance of overexpressing AmpC β-lactamases in cefoxitin-resistant Gram-negative bacillus must be enhanced.The therapy of infections caused by related bacillus should make imipenem and meropenem a chief choice.DHA-1,CMY-2 and CMY-22 AmpC enzymes are found in Fuzhou.更多还原