Zavascki Alexandre Prehn, Barth Afonso Luís, Gonçalves Ana Lúcia Saraiva, Moro Ana Lúcia Didonet, Fernandes Juliana Fernandez, Martins Andreza Francisco, Ramos Fabiano, Goldani Luciano Zubaran
Infectious Diseases Service, Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul Porto Alegre, Brazil.
J Antimicrob Chemother. 2006 Aug;58(2):387-92. doi: 10.1093/jac/dkl239. Epub 2006 Jun 3.
To assess the effect of metallo-beta-lactamase (MBL) production on Pseudomonas aeruginosa nosocomial infection mortality and to identify the determinants of such effect.
A cohort study of patients with P. aeruginosa nosocomial infections was conducted at two teaching hospitals. MBL was detected by ceftazidime/2-mercaptopropionic disc approximation test and selected isolates were submitted to PCR using bla(SPM-1) primer. Molecular typing was performed by DNA macrorestriction. To evaluate the influence of MBL on mortality a Cox proportional hazards model was performed using a hierarchized framework of the variables.
A total of 298 patients with P. aeruginosa infections were included. Infections by MBL-carrying Pseudomonas aeruginosa (MBL-PA) resulted in higher in-hospital mortality than those by non-MBL-PA (51.2% versus 32.1%, respectively; relative risk 1.60, 95% CI 1.20-2.12) and higher mortality rates [17.3 per 1000 versus 11.8 per 1000 patient-days, respectively; hazard ratio (HR) 1.55, 95% CI 1.06-2.27]. In the final multivariate model, severe sepsis or septic shock [adjusted HR (AHR) 3.62, 95% CI 2.41-5.43], age (AHR 1.02, 95% CI 1.01-1.03) and use of appropriate therapy<or=72 h (AHR 0.49, 95% CI 0.32-0.76) were significantly associated with mortality. Fourteen MBL-PA tested carried the blaSPM-1 gene. Clonal dissemination was documented in both hospitals.
MBL-PA infections resulted in higher mortality rates most likely related to the severity of these infections and less frequent early institution of appropriate antimicrobial therapy. Empirical treatments should be reviewed at institutions with high prevalence of MBL.
评估金属β-内酰胺酶（MBL）的产生对铜绿假单胞菌医院感染死亡率的影响，并确定这种影响的决定因素。
在两家教学医院对铜绿假单胞菌医院感染患者进行队列研究。通过头孢他啶/2-巯基丙酸纸片扩散试验检测MBL，并使用bla(SPM-1)引物对选定的分离株进行PCR。通过DNA宏观限制性分析进行分子分型。为了评估MBL对死亡率的影响，使用变量的分层框架进行Cox比例风险模型分析。
共纳入298例铜绿假单胞菌感染患者。携带MBL的铜绿假单胞菌（MBL-PA）感染导致的院内死亡率高于非MBL-PA感染（分别为51.2%和32.1%；相对风险1.60，95%可信区间1.20-2.12），且死亡率更高[分别为每1000患者日17.3例和11.8例；风险比（HR）1.55，95%可信区间1.06-2.27]。在最终的多变量模型中，严重脓毒症或脓毒性休克[调整后HR（AHR）3.62，95%可信区间2.41-5.43]、年龄（AHR 1.02，95%可信区间1.01-1.03）以及在≤72小时内使用适当治疗（AHR 0.49，95%可信区间0.32-0.76）与死亡率显著相关。检测的14株MBL-PA携带blaSPM-1基因。两家医院均记录到克隆传播。
MBL-PA感染导致更高的死亡率，这很可能与这些感染的严重程度以及早期适当抗菌治疗的频率较低有关。在MBL高流行的机构应审查经验性治疗。
