摘要
目的了解2007年安徽地区产质粒介导AmpC酶的大肠埃希菌检出率及产酶株基因型。方法三维实验进行AmpC酶筛选;并行转移接合实验,PCR检测AmpC酶基因,琼脂稀释法进行药物敏感试验。结果21株大肠埃希菌三维实验阳性,占所有临床分离菌株的5.9%(21/355),19株经PCR检测携带ampC基因,16株转移接合成功,经序列分析表明,9株CIT阳性结果,6株DHA阳性结果,3株EBC阳性结果;1株同时携带EBC及DHA基因。其中有1株EBC型新基因被检出(序列号为FJ237369);药敏结果显示临床分离菌株及接合子对多种抗菌药物耐药,对头孢吡肟,亚胺培南,美罗培南相对较敏感。结论安徽地区大肠埃希菌产质粒介导AmpC酶以CIT型和DHA型为主,同时存在变异型,临床可选用第四代头孢菌素类抗菌药物,碳青霉烯类抗菌药物抗感染治疗。
Objective To identify the AmpC gene and prevalence in Escherichia coli strains isolated from Anhui province in 2007. Methods Drug resistant test of Mueller-Hinton agar dilution and three-dimensional experiment was adopted to detect AmpC β-1actamases, conjugation experiment was done. Groups of AmpC were detected by specific PCR in all AmpCs-producing Escherichia coli strains. The PCR products were directly sequenced and analyzed. Results Twenty one strains of Escherichia coli were positive in three-dimensional experiment. Positive amplification results were observed for 21 Escherichia coli isolates which producing AmpCs. The percentage of plasmid-mediated AmpC-producing isolates in all isolates detected by conjugation was 4.5% （16/355）. Sequence and Blastn results indicated that 9 strains; positive for CIT group were found and 6 strains positive for DHA group were found;but only 3strains for EBC group were found. One single strain harboured both EBC and DHA gene. A novel EBC gene was confirmed by DNA sequence analysis （GenBank accession is FJ237369）. All wild-type isolates exhibited the highest resistant rate to most β-1actams and were susceptible to cefepime, imipenem and meropenem. Conclusions Plasmid-mediated ampC genes were found in Escherichia coli strains isolated from Anhui province and CIT and DHA were the mainly epidemic genotypes in our area. It suggested that carbopenems and the fourth generation cephalosporins could be chosen in clinical empirical medication.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2010年第2期143-147,共5页
Chinese Journal of Antibiotics
基金
国家自然科学基金项目(30772286)
安徽省自然科学基金(070413110)
关键词
质粒介导
大肠埃希菌
AMPC酶
耐药性
Plasmid-mediated
Escherichia coli
AmpC β-lactamases
Drug-resistance
