Safari Marzieh, Saidijam Massoud, Bahador Abas, Jafari Rasool, Alikhani Mohammad Yousef
Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
J Res Health Sci. 2013 Sep 17;13(2):162-7.
Acinetobacter baumannii is gram- negative opportunistic coccobacilli, the most important agent in nosocomial infections with high mortality rate. Multidrug resistance in strains isolated from nosocomial infections, making it difficult to treat and sometimes impossible. The aim of the present study was to investigate antibiotic resistance in A. baumannii isolates from Iranian patients in Hamadan, west of Iran.
In this cross sectional study 100 A. baumannii isolated from trachea, blood, urine, sputum and wound samples of patients bedridden in Intensive care unit (ICU) wards of three educational hospitals during June 2011 to October 2012 was included. Isolates confirmed at species level using biochemical tests and tracing blaOXA-51 gene using Polymerase chain reaction (PCR) and preserved frozen at -70 °C until examination. Their susceptibility to 17 antibiotics was performed using Kirby-Bauer disc diffusion method. Determination of minimum inhibitory concentration and Metallo-beta-lactamase production was carried out using E-test method.
Resistance rate of isolates were 94%, 85%, 84%, 97%, 95% and 98% against meropenem, imipenem, amikacin, ciprofloxacin, piperacillin/tazobactam and cefotaxime, respectively. No resistant isolate was observed against tigecycline and also no sensitive isolate seen against aztreonam and cefotaxime. Results of E-test illustrated that 99% of all isolates were Metallo-beta-lactamase (MβL) producing, which were resistance to imipenem; also 85% of them were resistance to meropenem. MIC50 and MIC90 of the isolates were ≥256 and ≥32 mg/ml for imipenem and meropenem, respectively.
The antibiotic resistance against most of the antibiotics, especially carbapenems is very high in Hamadan region. In addition colistin sulfate and tigecycline were most effective antibiotics and to be used in A. baumannii infections.
鲍曼不动杆菌是革兰氏阴性机会性球杆菌，是医院感染中最重要的病原体，死亡率很高。从医院感染中分离出的菌株具有多重耐药性，使其难以治疗，有时甚至无法治疗。本研究的目的是调查伊朗西部哈马丹地区伊朗患者分离出的鲍曼不动杆菌的抗生素耐药性。
在这项横断面研究中，纳入了2011年6月至2012年10月期间从三家教学医院重症监护病房（ICU）卧床患者的气管、血液、尿液、痰液和伤口样本中分离出的100株鲍曼不动杆菌。使用生化试验在种水平上确认分离株，并使用聚合酶链反应（PCR）追踪blaOXA-51基因，并在-70°C下冷冻保存直至检测。使用 Kirby-Bauer 纸片扩散法检测它们对17种抗生素的敏感性。使用E-test法测定最低抑菌浓度和金属β-内酰胺酶的产生。
分离株对美罗培南、亚胺培南、阿米卡星、环丙沙星、哌拉西林/他唑巴坦和头孢噻肟的耐药率分别为94%、85%、84%、97%、95%和98%。未观察到对替加环素耐药的分离株，也未观察到对氨曲南和头孢噻肟敏感的分离株。E-test结果表明，所有分离株中有99%产生金属β-内酰胺酶（MβL），对亚胺培南耐药；其中85%对美罗培南耐药。分离株对亚胺培南和美罗培南的MIC50和MIC90分别≥256和≥32mg/ml。
哈马丹地区对大多数抗生素，尤其是碳青霉烯类抗生素的耐药性非常高。此外，硫酸黏菌素和替加环素是治疗鲍曼不动杆菌感染最有效的抗生素。
