2003—2004年中国十家教学医院革兰阴性杆菌的耐药分析

Antimicrobial resistance analysis among nosocomial gram-negative bacilli from 10 teaching hospitals in China

目的连续监测2003—2004年中国不同地区十家教学医院临床分离的革兰阴性杆菌的耐药性。方法非重复的1760株革兰阴性杆菌中,2003年871株,2004年889株。菌株经中心实验室复核后,采用琼脂稀释法测定美罗培南等数十种广谱抗菌药物的最低抑菌浓度(MICs),数据分析采用WHONET5.3软件。结果10种抗菌药物对于1115株肠杆菌科细菌的抗菌活性,敏感率依次为:美罗培南、亚胺培南(敏感率99%)>哌拉西林/三唑巴坦(86.3%)>阿米卡星(81.8%)>头孢吡肟(76.5%)、头孢哌酮/舒巴坦(75.1%)>头孢他啶(74.8%)>头孢噻肟(54.8%)、头孢曲松(51.8%)>环丙沙星(48.6%);美罗培南、亚胺培南的MIC90分别为0.125μg/ml、1μg/ml。超广谱β内酰胺酶(ESBL)的发生率,大肠埃希菌(56.8%)高于肺炎克雷伯菌(42.3%)和奇异变形杆菌(12.1%)。对于大肠埃希菌,抗菌活性在80%以上的药物除碳青霉烯类之外,还有哌拉西林/三唑巴坦(93.4%)、头孢他啶(86%)和阿米卡星(83.3%);肺炎克雷伯菌对哌拉西林/三唑巴坦的敏感性为84.6%,头孢他啶的敏感性从82.3%降至69.9%,低于头孢吡肟(77.2%)。50%以上的阴沟肠杆菌对头孢他啶、头孢噻肟、头孢曲松耐药。阴沟肠杆菌、产气肠杆菌、弗劳地枸橼酸菌和黏质沙雷菌对哌拉西林/三唑巴坦的敏感率(67.7%～96.4%)略高于头孢吡肟(68.8%～77.5%)及头孢哌酮/舒巴坦(59.7%～87.5%)。这4种菌对阿米卡星的敏感率(70%～83.7%)高于环丙沙星(48.1%～79.5%)。所有摩根摩根菌和普通变形杆菌对美罗培南、亚胺培南敏感,头孢吡肟、头孢哌酮/舒巴坦、哌拉西林/三唑巴坦的敏感性在90%以上。绿脓假单胞菌对美罗培南的敏感性最高(84%),其次是阿米卡星、哌拉西林/三唑巴坦、头孢他啶和亚胺培南(72.5%～76.6%)。多重耐药的鲍曼不动杆菌从2003年的33%升至2004年的48%,2004年此菌对碳青霉烯类的耐药率增至18%。对于洋葱伯克霍尔德菌,敏感性最高的药物是美罗培南(64.9%)、头孢哌酮/舒巴坦(63.2%)、头孢他啶(59.6%)、哌拉西林/三唑巴坦(56.1%)和头孢吡肟(52.6%)。结论碳青霉烯类对肠杆菌科仍保持高活性,但非发酵糖菌,特别是鲍曼不动杆菌的耐药性明显增加,值得关注。对于常见的革兰阴性杆菌,美罗培南比亚胺培南的抗菌活性强4～16倍。

Objective To continuously investigate antimicrobial resistance among nosocomial gramnegative bacilli isolated from 10 teaching hospitals at different cities in China from 2003 to 2004. Methods During two-study period, 1 760 consecutive and non-repetitive gram-negative bacilli （871 isolates in 2003 and 889 isolates in 2004） were collected and sent to the central lab for reidentification and susceptibility testing. The minimal inhibitory concentration （MICs） of meropenem and other antibacterial agents were determined by agar dilution method. Whonet 5.3 software was used to analyze the data. Results During 2- study period, the activity of antibacterial agents against Enterobaeteriaeeae was as follows in order： meropenem, imipenem （ susceptible rate, 99% ） 〉 piperacillin/tazobactam （ 86. 3% ） 〉 amikacin （81.8%） 〉 cefepime （76.5%）, cefoperazone/sulbactam （75.1%） 〉 ceftazidime （74.8%） 〉 cefotaxime （ 54. 8% ）, ceftriaxone （ 51.8% ） 〉 ciprofloxacin （ 48.6% ）. MIC90 of meropenem against 1 115 isolates of Enterobacteriaceae was much lower than imipenem （0. 125 μg/ml vs. 1 μg/ml）. The prevalence of extended-spectrum β-lactamases （ESBL） was 56. 8% in Escherwhia coli, 42.3% in Klebsiella pneumoniae and 12. 1% in Proteus mirabilis. In addition to earbapenems, the agents with 〉 80% activity rate against E. coli included piperacillin/tazobactam（ 93.4% ） ,ceftazidime（ 86% ）, and amikacin（ 83.3% ） ; The susceptible rate to piperacillin/tazobactam in K. pneumoniae was 84. 6%. The susceptible rate to ceftazidime decreased from 82.3% to 69. 9% , which was lower than to cefepime （77.2%）. Over 50% of Enterobaeter cloacae were resistant to ceftazidime, cefotaxime and ceftriaxone. Susceptible rates to piperacillin/tazobactam in E. cloacae, E. aerogenes, Citrobacter freundii and Serratla marcescens （ 67.7% - 96.4% ） were higher than those to cefepime （68.8% -77.5% ）, cefoperazone/sulbactam （59.7%-87.5% ） Susceptibility to amikacin among these 4 species （70%-83.7%） was higher than to ciprofloxacin （48.1%-79.5% ）. All of Morganella morganii and Proteus vulgaris isolates were susceptible to meropenem and imipenem; Over 90% of the isolates were susceptible to cefepime, cefoperazone/sulbactam and piperacillin/tazobactam. The most active agent against Pseudomonas aeruginosa was meropenem （84%）, followed by amikacin, piperacillin/tazobactam, ceftazidime and imipenem （72. 5%-76.6% ）. Mutiple-drug- resistant Acinetobaeter baumannii increased from 33% in 2003 to 48% in 2004. Resistance to carbapenems increased to 18% in this species in 2004. The most active agents against Burkholderia cepaeia were meropenme （64.9%）, cefoperazon/sulbactam （63.2%）, ceftazidime （59. 6% ）, piperacillin/tazobactam （56. 1% ） and cefepime （52.6%）. Conclusions Carbapenems remained very high activity against Enterobacteriaceae. Increasing resistance to 10 antimicrobials agents tested among A. baumanni brought great concern. Meropenem was 4-to 16-fold more active against common gram-negative bacilli than imipenem.