产β-内酰胺酶革兰阴性杆菌的筛选和耐药性分析

Screen of β-lactamase in the multi-resistant gram-negative bacilli and analysis of drug resistence

目的以多重耐药革兰阴性菌为对象,检测β-内酰胺酶表型,了解其耐药特性和分布特点。方法采用纸片扩散初筛法、扩散确证法、头孢西丁三维试验、甘露聚糖结合凝集素(MBL)的协同试验进行确证;采用法国梅里埃API生化鉴定试条或经VITEK-2鉴定系统将细胞鉴定到种;药敏试验用琼脂纸片扩散(K-B)法,经WHO-NET5.0软件进行统计学分析,分析其耐药特性。结果多重耐药革兰阴性杆菌β-内酰胺酶总检出率为26.4%(80/302),主要由产超广谱β-内酰胺酶(ESBLs)引起,占16.56%(50/302);其次为ESBLs+AmpC引起,占6.62%(20/302);ESBLs+AmpC+MOL引起,占1.66%(5/302),单独由AmpC引起的仅占0.66%(2/302),有3株未能定型占0.99%(3/302)。多重耐药革兰阴性杆菌对临床常用抗生素的总体耐药率最低的为阿米卡星(18.99%)、其次为亚胺培南(20.0%),头孢哌酮/舒巴坦(21.7%)、哌拉西林/他唑巴坦(21.89%);最高的为氨苄西林(98.33%),其次为氨苄西林/舒巴坦(83.33%)、头孢曲松(76.25%)、头孢西丁(63.64%)及头孢噻肟(60.50%)等,大部分细菌呈多重耐药性。结论产多种β-内酰胺酶的革兰阴性菌具有多重耐药。

[Abstract] Objective To screen the β-lactamase in the multi-resistant gram-negative bacilli,and to assess the characteristics of the drug resistant and distribution. Methods 302 multi-resistant gram-negative strains with suspec- ted producing ]3-lactamase were detected by disc diffusion screen test, which were further ascertained by disc diffu- sion confirmatory test, a cefoxitin three dimensional test, metallo B-lactamases double-disc synergy test. These iso- lates were identified by using the API system. Antibiotics susceptibility was detected by K-B method,WHONET5.0 was used for data analysis. Results Among 302 clinical multi-resistant gram-negative isolates,total detection rate of stains produced β -lactamases was 26.4 % （80/302）, these rates of ESBLs, ESBLs combined with AmpC enzymes ES- BLs combined with AmpC enzyme and MBL, and AmpC enzyme producing strains were 16.56 % （50/302）, 6.62 % （20/302） ,1.66% （5/302） and 0.66% （2/302） respectively. Drug-sensitivity test showed that multi-resistant gram- negative isolates sensitive rates from low to high in turn were Amikacin（ 18.99 % ）, Imipenem （20.0%）, Cefopera- zone/Sulbactam（21.7%） ,Ampicillin/Sulbactam（21.8%）. Resistant rates from high to low in turn were Ampicillin （ 98. 33 % ）, Ampicillin/Sulbactam （ 83. 33 % ）, Ceftriaxone （ 76.25 % ）, Cefoxitin （ 63. 64 % ）, Cefotaxime （ 60. 50 %）. Conclusion β-laetamase producing gram-negative bacilli can be resistant to multi antibiotics.