Sánchez-Encinales Viviana, Álvarez-Marín Rocío, Pachón-Ibáñez María Eugenia, Fernández-Cuenca Felipe, Pascual Alvaro, Garnacho-Montero José, Martínez-Martínez Luis, Vila Jordi, Tomás María Mar, Cisneros José Miguel, Bou Germán, Rodríguez-Baño Jesús, Pachón Jerónimo, Smani Younes
Clinic Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville, IBiS, University Hospital Virgen del Rocío/CSIC/University of Seville, Spain.
Infectious Diseases and Clinical Microbiology Unit, University Hospital Virgen Macarena, University of Seville, Spain.
J Infect Dis. 2017 Mar 15;215(6):966-974. doi: 10.1093/infdis/jix010.
Outer membrane protein A (OmpA) is a porin involved in Acinetobacter baumannii pathogenesis. However, OmpA clinical implication in hospital-acquired infections remains unknown. We aimed to determine whether OmpA overproduction was a risk factor associated with pneumonia, bacteremia, and mortality.
We analyzed demographic, microbiological, and clinical data from 100 patients included in a unicenter cohort and 246 included in a unicenter cohort and a multicenter cohort. Representative isolates were classified into 2 groups: (1) isolates from patients colonized by A. baumannii (16 from the unicenter and 20 from the multicenter cohort) and (2) isolates from bacteremic or nonbacteremic patients with pneumonia (PP) caused by A. baumannii (13 from the unicenter and 23 from the multicenter cohort) Expression of ompA was determined with quantitative reverse-transcription polymerase chain reaction.
Isolates from PP overexpressed more ompA than those from colonized patients from the unicenter (ratio, 1.76 vs 0.36; P < .001) and the multicenter (1.36 vs 0.91; P = .03) cohorts. Among isolates from PP, those from bacteremic patients overexpressed nonsignificantly more ompA than those from nonbacteremic patients in the unicenter (ratio, 2.37 vs 1.43; P = .06) and the multicenter (2.03 vs 0.91; P = .14) cohorts. Multivariate analysis in both cohorts together showed ompA overexpression as independent risk factor for pneumonia (P < .001), bacteremia (P = .005), and death (P = .049).
These data suggest that ompA overexpression is an associated factor for pneumonia, bacteremia, and death due to A. baumannii.
外膜蛋白A（OmpA）是一种参与鲍曼不动杆菌致病过程的孔蛋白。然而，OmpA在医院获得性感染中的临床意义仍不清楚。我们旨在确定OmpA过度表达是否是与肺炎、菌血症和死亡率相关的危险因素。
我们分析了来自一个单中心队列的100例患者以及一个单中心队列和一个多中心队列的246例患者的人口统计学、微生物学和临床数据。代表性分离株分为两组：（1）来自鲍曼不动杆菌定植患者的分离株（单中心队列16株，多中心队列20株）；（2）来自鲍曼不动杆菌引起的菌血症或非菌血症肺炎患者（PP）的分离株（单中心队列13株，多中心队列23株）。采用定量逆转录聚合酶链反应测定ompA的表达。
来自PP患者的分离株比来自单中心队列定植患者的分离株（比值为1.76对0.36；P <.001）和多中心队列定植患者的分离株（1.36对0.91；P =.03）过度表达更多的ompA。在来自PP患者的分离株中，来自菌血症患者的分离株比来自单中心队列（比值为2.37对1.43；P =.06）和多中心队列（2.03对0.91；P =.14）非菌血症患者的分离株非显著性地过度表达更多的ompA。两个队列的多变量分析共同显示ompA过度表达是肺炎（P <.001）、菌血症（P =.005）和死亡（P =.049）的独立危险因素。
这些数据表明ompA过度表达是鲍曼不动杆菌所致肺炎、菌血症和死亡的相关因素。
