title: Gastropulmonary Route of Infection and the Prevalence of Microaspiration in the Elderly Patients with Ventilator-Associated Pneumonia Verified by Molecular Microbiology-GM-PFGE.
abstract: Gastropulmonary route of infection was considered to be an important mechanism of ventilator-associated pneumonia (VAP). However there is little evidence to support this assumption. Moreover, the prevalence of microaspiration in elderly ventilated patients was not well understood. To confirm gastropulmonary infection route and investigate the prevalence of microaspiration in elderly ventilated patients using genome macrorestriction-pulsed field gel electrophoresis (GM-PFGE). Patients over 60 years old, expected to receive mechanical ventilation longer than 48 h, were prospectively enrolled from October 2009 to January 2012. Clinical data were collected and recorded until they died, developed pneumonia, or were extubated. Samples from gastric fluid, subglottic secretion and lower respiratory tract (LRT) were collected during the follow-up for microbiological examination. To evaluate the homogeneity, GM-PFGE was performed on strains responsible for VAP that had the same biochemical phenotype as those isolated from gastric juice and subglottic secretions sequentially. Among 44 VAP patients, 76 strains were isolated from LRT and considered responsible for VAP. Twenty-two isolates had the same biochemical phenotype with the corresponding gastric isolates. The homology was further confirmed using GM-PFGE in 12 episodes of VAP. Nearly 30% of VAPs were caused by microaspiration based on the analysis of bacterial phenotype or GM-PFGE. In addition, 58.3% patients with gastric colonization developed VAP, especially late-onset VAP (LOP). Gastropulmonary infection route exists in VAP especially LOP in elderly ventilated patients. It is one of the important mechanisms in the development of VAP.
authors.affiliation: Department of Pulmonary Medicine, Provincial Hospital, Shandong University, 9677 Jingshi East Road, Jinan, 250021, People's Republic of China. liuqinghuadr@sina.com.
authors.forename: Qing-hua
authors.initials: QH
authors.lastname: Liu
authors.affiliation: Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Pulmonary Medicine, Provincial Hospital, Shandong University, 9677 Jingshi East Road, Jinan, 250021, People's Republic of China. lzlqhlz@163.com.
authors.forename: Dian-jie
authors.initials: DJ
authors.lastname: Lin
authors.affiliation: Department of Pulmonary Medicine, Provincial Hospital, Shandong University, 9677 Jingshi East Road, Jinan, 250021, People's Republic of China.
authors.forename: Xiao-yan
authors.initials: XY
authors.lastname: Mou
authors.affiliation: Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China. lixianhe@yahoo.com.cn.
authors.forename: Li-xian
authors.initials: LX
authors.lastname: He
authors.affiliation: Department of Pulmonary Medicine, Huadong Hospital, Fudan University, Shanghai, 200040, People's Republic of China.
authors.forename: Jie-ming
authors.initials: JM
authors.lastname: Qu
authors.affiliation: Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China.
authors.forename: Hua-yin
authors.initials: HY
authors.lastname: Li
authors.affiliation: Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China.
authors.forename: Bi-jie
authors.initials: BJ
authors.lastname: Hu
authors.affiliation: Shanghai Institute of Plant Physiology, Shanghai Institutes of Biological Sciences, The Chinese Academy of Sciences, Shanghai, 200032, People's Republic of China.
authors.forename: Ying-min
authors.initials: YM
authors.lastname: Zhu
authors.affiliation: Surgical Intensive Care Unit, Zhongshan Hospital, Fudan University, Shanghai, 200032, People's Republic of China.
authors.forename: Du-ming
authors.initials: DM
authors.lastname: Zhu
authors.affiliation: Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China.
authors.forename: Xiao-dong
authors.initials: XD
authors.lastname: Gao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D008168:Lung / Q000382:microbiology*; D008297:Male; D008829:Microbiology; D008875:Middle Aged; D009960:Oropharynx / Q000382:microbiology; D053717:Pneumonia, Ventilator-Associated / Q000209:etiology* / Q000382:microbiology* / Q000601:surgery; D015995:Prevalence; D013270:Stomach / Q000382:microbiology*; D013396:Suction
chemical_list: D004269:DNA, Bacterial
keywords: Gastropulmonary route; Genome macrorestriction-pulsed field gel electrophoresis; Ventilator-associated pneumonia