Hermanos Ameijeiras Hospital, Havana, Cuba.
Braz J Infect Dis. 2012 Jan-Feb;16(1):45-51.
This observational study described the characterization of bacteria isolated from the lower respiratory tract of ventilated patients hospitalized in intensive care units. The demonstration of isolated microorganism resistance to antibiotics and a time-trend analysis of infection comparing a 48-month period were also other objectives.
Semi-quantitative assays of 1254 samples taken from 741 ventilated patients were performed, while pathogens were identified using the Enterotube II assay and VITEK 2 Compact equipment. Bacterial resistance to antibiotics was assessed by the Kirby-Bauer disc diffusion method and time-trend analysis of infection was based on data recorded by hospital microbiology laboratories.
The most prevalent isolated bacteria from the patient's lower respiratory tract were with Gram-negative bacteria (67.8%) mostly represented by: Acinetobacter spp. (25.2%), Pseudomonas spp. (18.3%) and Klebsiellas spp. (9.4%). Acinetobacter spp. showed moderate high to very high resistance to ceftriaxone (CRO), gentamicin (CN), amikacin (AK), meropenem (MRP), aztreonam (ATM) and piperacillin/tazobactam (TZP). Some isolates of Acinetobacter spp. resistant to colistin (CS) were identified in this patient population. Pseudomonas spp. and Klebsiella spp. were very highly resistant to ampicillin/sublactam (AMS) and with moderate or low resistance to CRO, ATM, MRP, AK, CN and TZP. A decrease in the Pseudomonas spp. prevalence rate was observed, whereas an increase in Acinetobacter spp. and Klebsiella spp. prevalence rates were observed in a 48-month period.
This research corroborated that these nosocomial infections are a relevant medical problem in our context. The most prevalent bacterial infections in the lower respiratory tract of ventilated patients were by Acinetobacter spp., Pseudomonas spp. and Klebsiella spp. The panel of antibiotics used as preventive therapy was not the solution of infections and probably induced drug-resistance mechanisms in these isolated microorganisms.
本观察性研究描述了从重症监护病房机械通气患者下呼吸道分离的细菌的特征。此外，还评估了分离微生物对抗生素的耐药性，并比较了 48 个月期间的感染时间趋势分析。
对 741 例机械通气患者的 1254 份样本进行半定量检测，使用 Enterotube II 检测和 VITEK 2 Compact 设备鉴定病原体。通过 Kirby-Bauer 圆盘扩散法评估细菌对抗生素的耐药性，并根据医院微生物学实验室记录的数据进行感染时间趋势分析。
患者下呼吸道最常见的分离细菌为革兰氏阴性菌（67.8%），主要为：不动杆菌属（25.2%）、铜绿假单胞菌（18.3%）和肺炎克雷伯菌（9.4%）。不动杆菌属对头孢曲松（CRO）、庆大霉素（CN）、阿米卡星（AK）、美罗培南（MRP）、氨曲南（ATM）和哌拉西林/他唑巴坦（TZP）显示中度至高度耐药。在该患者群体中发现了一些对黏菌素（CS）耐药的不动杆菌属分离株。铜绿假单胞菌和肺炎克雷伯菌对氨苄西林/舒巴坦（AMS）高度耐药，对 CRO、ATM、MRP、AK、CN 和 TZP 中度或低度耐药。在 48 个月期间，观察到铜绿假单胞菌的流行率下降，而不动杆菌属和肺炎克雷伯菌的流行率增加。
本研究证实，这些医院获得性感染是我们所处环境中的一个重要医学问题。机械通气患者下呼吸道最常见的细菌感染是由不动杆菌属、铜绿假单胞菌和肺炎克雷伯菌引起的。作为预防治疗使用的抗生素方案并未解决感染问题，并且可能在这些分离微生物中诱导了耐药机制。
