Infection route inventilator associated pneumonia: the molecular epidemiological study

Abstract

：Objective To evaluatethe role of infection route in the pathogens of ventilator associated pneumonia (VAP) bymolecular epidemiological methods. Methods A study was made in artificial airway patientsincluded trachea intubated or tracheotomied patients in intensive care units (ICU).Pathogen cultivation and antibiotic sensitivity test of the samples collected from lowerrespiratory tract, gastric cavity, oropharynx. ballonet (artificial airway), air (aroundpatients), hand (nurse),ventilator pipeline and seeper bottles were made. The bacteriaisolated from all kinds of specimens and showed same biochemical characteristics wereanalyzed by phenotypic method and pulse field gel electrophoresis (PFGE) to study theirhomology. Results Twenty two cases of the total 48 intubated patients supported bymechanical ventilation developed VAP. There were 17 patients whose pathogen cultivationsof lower respirotery tract sample were positive. Gram negative bacillis were dominatingand pseudomonas aeruginosa standed first on the list. Pathogens of ballonet, gastriccavity tallied with pathogens of lower respiratery tract greatly by PFGE analysis.Conclusions The PFGE homologous analysis of pathogen showed that ballonet, gastric cavitywere the most important lower respiratory tract infection route in VAP patients. We shouldpay more attention to them.