云南大理医院ICU产ESBLs细菌基因型及耐药性分析

Genotypes and drug resistance of ESBL-producing strains isolated from a hospital intensive care unit in Dali,Yunnan

目的了解2010年大理学院附属医院重症监护病房(ICU)产超广谱β-内酰胺酶(ESBLs)细菌基因型及耐药情况。方法 2010年1～12月ICU分离的大肠埃希菌43株,肺炎克雷伯菌27株,采用CLSI(2009)推荐的纸片扩散法进行ESBLs表型检测,基因型检测采用PCR法,药敏试验采用MIC法。结果 70株细菌中检出32株产ESBLs细菌,检出率为45.71%;PCR结果显示CTX-M、SHV、TEM-1基因型分别有21株、14株和5株,6株细菌携带2种以上基因型;产酶株对亚胺培南均敏感,对氨苄西林耐药率达100%,对头孢菌素和环丙沙星的耐药率亦较高(50%～85%),而对氨苄西林/舒巴坦、哌拉西林/舒巴坦和丁胺卡那耐药率较低(<25%)。结论 ICU产ESBLs菌检出率较高,耐药情况严重,临床医疗过程中应合理使用抗生素,同时加强产酶株的监测。

Objective To investigate the genotypes and drug resistance of extended spectrum β-lactamase（ESBL）-producing strains isolated from the Intensive Care Unit（ICU） of the hospital affiliated with Dali University in 2010.Methods 43 isolates of Escherichia coli and 27 isolates of Klebsiella pneumoniae were collected from January to December 2010.The phenotypes and genotypes of ESBLs were determined using the Kirby-Bauer method and PCR,respectively.An antibiotic susceptibility test was performed using the broth dilution method.Results Thirty-two of 70 isolates were ESBL-producing strains,representing 45.7%.PCR indicated that 21 strains were positive for CTX-M,14 were positive for SHV,and 5 were positive for TEM-1.Six isolates expressed two more genotypes.All ESBL-producing isolates were sensitive to imipenem and resistant to ampicillin.Isolates had higher rates of resistance to cephalosporins and ciprofloxacin（50%-85%） but rates of resistance to β-lactamase inhibitors and amikacin were less than 25%.Conclusion E.coli and K.pneumoniae isolates from the ICU were ESBL-producing strains and highly drug-resistant.Antibiotics must be used rationally in clinical practice and ESBL-producing strains must be monitored further.