CAJ | 학술논문

目的：了解临床分离肠杆菌菌种分布及对碳青霉烯类抗菌药物的耐药现状和分子机制。方法收集四川大学华西医院2009~2010年分离到的对碳青霉烯类药物敏感性降低的肠杆菌科非重复菌株共45株，测定其对常用抗菌药物的最低抑菌浓度（MIC）以及产酶表型和PCR检测产酶分子机制。结果对碳青霉烯类药物敏感性降低的45株肠杆菌科细菌中，17株菌对亚胺培南中介或耐药，21株对美罗培南中介或耐药，36株对厄他培南中介或耐药，绝大多数菌株对头孢菌素类耐药。受试菌株中改良Hodge试验阳性检出率最高（77.8%），其次为EDTA纸片增效试验（57.8%）和PBA纸片增效试验（22.2%）。blaTEM、blaSHV和blaCTX-M基因检出率分别为60.0%，53.3%和15.6%，同时携带2种及以上基因的检出率为44.4%。blaIMP基因检出率为48.9%。4株菌（3株产酸克雷伯菌，1株阴沟肠杆菌）为blaKPC基因阳性，检出率为8.9%，且位于质粒上。结论研究发现肠杆菌科细菌产酶是对碳青霉烯类药物敏感性下降的主要机制，产碳青霉烯酶或合并多种β-内酰胺酶可引起非敏感或耐药的出现。本研究报道了在西南地区发现在质粒携带的KPC-2型酶，可能引起不同菌种间水平传播，需引起足够重视。
목적：료해림상분리장간균균충분포급대탄청매희류항균약물적내약현상화분자궤제。방법수집사천대학화서의원2009~2010년분리도적대탄청매희류약물민감성강저적장간균과비중복균주공45주，측정기대상용항균약물적최저억균농도（MIC）이급산매표형화PCR검측산매분자궤제。결과대탄청매희류약물민감성강저적45주장간균과세균중，17주균대아알배남중개혹내약，21주대미라배남중개혹내약，36주대액타배남중개혹내약，절대다수균주대두포균소류내약。수시균주중개량Hodge시험양성검출솔최고（77.8%），기차위EDTA지편증효시험（57.8%）화PBA지편증효시험（22.2%）。blaTEM、blaSHV화blaCTX-M기인검출솔분별위60.0%，53.3%화15.6%，동시휴대2충급이상기인적검출솔위44.4%。blaIMP기인검출솔위48.9%。4주균（3주산산극뢰백균，1주음구장간균）위blaKPC기인양성，검출솔위8.9%，차위우질립상。결론연구발현장간균과세균산매시대탄청매희류약물민감성하강적주요궤제，산탄청매희매혹합병다충β-내선알매가인기비민감혹내약적출현。본연구보도료재서남지구발현재질립휴대적KPC-2형매，가능인기불동균충간수평전파，수인기족구중시。
Objectives To analyze the distribution of Enterobacteriaceae isolated from West China Hospital, investigate the antibiotic resistance profile of Enterobacteriaceae with decreased susceptibility to carbapenems and explore the molecular mechanism. Methods Forty- five Enterobacteriaceae strains resistant or with reduced susceptibility to carbapenems were isolated from patients in West China Hospital. The antimicrobial susceptibility and carbapenemase-producing phenotypes of the bacteria were examined and specific PCR were performed to determine the molecular mechanism. Results Of the 45 isolates, 17, 21 and 36 were resistant or intermediate strains to imipenem, meropenem and ertapenem, respectively. The majority of these isolates showed resistance to cephalosporins. The modified Hodge test resulted in the highest positivity rate (77.8%), followed by EDTA disc test (57.8%) and PBA disc test (22.2%). BlaTEM, blaSHV and blaCTX-M were detected in 60.0%, 53.3% and 15.6% of these strains with reduced susceptibility. The rate of strains carrying 2 or more genes was 44.4%, and the detection rate of blaIMP was 48.9%. BlaKPC was identified in 4 (8.9%) high-level resistant strains and confirmed to locate on the plasmid. Conclusion Production of carbapenemase contributes to reduced susceptibility of carbapenems in Enterobacteriaceae. The presence of blaKPC, MBL and ESBL, and their possible combinations can be the main factor contributing to carbapenem resistance or reduced susceptibility in Enterobacteriaceae. The KPC- 2 carbapenemase gene located on the plasmids we found in this study can cause potential horizontal transmission across strains.