产β-内酰胺酶气单胞菌检测及耐药性分析

Determining of Aeromonas of β-lactamases-producing Isolates and Analysis of Resistance

目的:检测从临床标本中分离的185株气单胞菌对10种抗菌药物的体外活性,及这些菌产AmpC酶、金属β-内酰胺酶、超广谱β-内酰胺酶的情况,指导临床正确合理使用抗生素。方法:用API-20NE和API-20E及补充生化试验对菌株进行鉴定;采用MIC法检测超广谱β-内酰胺酶和AmpC酶;改良Hodge试验检测金属β-内酰胺酶;MIC测定采用琼脂稀释法。结果:气单胞菌的产酶率为9.3%(19/185),其中AmpC酶为1.6%(3/185),金属β-内酰胺酶为2.7%(5/185),超广谱β-内酰胺酶为6.5%(12/185)。氨苄西林敏感性低,三代头孢菌素和氨基甙类的敏感率在80%左右,四代头孢菌素、亚胺培南和氟喳诺酮类敏感率大于90%。结论:实验室有必要加强对产β-内酰胺酶气单胞菌的检测。氟喹诺酮类是治疗气单胞菌感染的首选药物,其次为氨基甙类。

Objective: The aim of this study was to determine the activity of 10 antibacterials against 185 strains of Aeromonas isolated from clinical specimens which produce AmpC β-lactamase, extended-spectrum β-lactamase and metallo β-lactamase so as to guide the rational application of antibiotics. Methods: Identification of the strains was performed by the API 20E, API 20NE systems and complementary biochemical tests. AmpC β-lactamases and extended-spectrum β-lactamases-producing isolates were determined by the results of MICs, mtallo-β-lactamases-producing isolates was determined by the modified Hodge test. MICs were determined by an agar dilution method. Results: The rate of producing β-lactamases of Aeromonas was 9.3%(19/185),respectiverly, AmpC β-lactamases was 1.6%(3/185),mtallo-β-lactamases was 2.7%(5/185), extended-spectrum β-lactamases was 6.5%(12/185). Most Aeromonas were poorly susceptible to ampicillin, The sensitive rates of Aeromonas clinical isolates to aminoglycosides and third-generation cephalosporins were about 80%, fourth-generation cephalosporins, imipenem and fluoroquinolones were more than 90% Conclusions: Clinical laboratorys must strengthen to determine Aeromonas of lactamases-producing isolates. Fluoroquinolones was the first candidate for the infectious conditions caused by the Aeromonas, aminoglycosides was second.