Obeidat Nathir, Jawdat Fatin, Al-Bakri Amal G, Shehabi Asem A
Department of Internal Medicine, Faculty of Medicine-Jordan, The University Hospital, Amman, Jordan.
Department of Pathology and Microbiology, Faculty of Medicine, The University of Jordan, Amman, Jordan.
Am J Infect Control. 2014 Apr;42(4):401-4. doi: 10.1016/j.ajic.2013.10.010.
This prospective study investigated major biologic characteristics of Acinetobacter baumannii isolates from hospital environment and respiratory tract samples of patients admitted to adult intensive care units (ICUs) at the Jordan University Hospital.
A baumannii isolates from both sources were examined for antimicrobial susceptibility and for presence of specific metallo-β-lactamase genes (VIM-2, IMP-1) and OXA-type β-lactamase genes (OXA-type) using polymerase chain reaction and biofilm formation and surviving under various temperatures and pH conditions.
The majority of A baumannii isolates from environmental and patients sources was multidrug resistant (MDR), except for colistin and tigecycline. All A baumannii examined carried a blaOXA51-like gene, 58% has a blaOXA23-like gene, and 38.8% has a blaOXA24-like gene. Representative MDR A baumannii isolates from both sources were capable to form biofilm. A baumannii environmental isolates were capable to survive for a longer time in tap, normal saline, and distilled water than respiratory tract isolates with pH range of 4.5 to 8 and temperature between 18°C to 37°C.
This study demonstrates that A baumannii isolates from the patients' respiratory tract and hospital environment carried much similar multidrug resistance patterns and biologic characteristics. In conclusion, this study shows that all MDR A baumannii strains survived well in the hospital environment, especially in water and moist environment and produced biofilm, which might be responsible for high colonization in the respiratory tract of patients in ICU.
这项前瞻性研究调查了约旦大学医院成人重症监护病房（ICU）患者的医院环境和呼吸道样本中分离出的鲍曼不动杆菌的主要生物学特性。
使用聚合酶链反应对来自这两种来源的鲍曼不动杆菌分离株进行抗菌药敏试验，检测特定金属β-内酰胺酶基因（VIM-2、IMP-1）和OXA型β-内酰胺酶基因（OXA型）的存在情况，并检测生物膜形成以及在不同温度和pH条件下的存活情况。
除黏菌素和替加环素外，来自环境和患者来源的大多数鲍曼不动杆菌分离株对多种药物耐药（MDR）。所有检测的鲍曼不动杆菌均携带blaOXA51样基因，58%具有blaOXA23样基因，38.8%具有blaOXA24样基因。来自这两种来源的代表性MDR鲍曼不动杆菌分离株能够形成生物膜。鲍曼不动杆菌环境分离株在自来水、生理盐水和蒸馏水中的存活时间比呼吸道分离株更长，pH范围为4.5至8，温度在18°C至37°C之间。
本研究表明，来自患者呼吸道和医院环境的鲍曼不动杆菌分离株具有非常相似的多药耐药模式和生物学特性。总之，本研究表明，所有MDR鲍曼不动杆菌菌株在医院环境中存活良好，尤其是在水和潮湿环境中，并产生生物膜，这可能是ICU患者呼吸道高定植率的原因。
