Study On The Bacterial Phage, Quorum Sensing System And Biofilms In Pseudomonas Aeruginosa

As an important opportunistic pathogen, Pseudomonas aeruginosa (P. aeruginosa, PA) was the most prevalent bacterial pathogens in infectious diseases, such as respiratory tract infections, bacteremia, pneumonia, urinary tract infections, cystic fibrosis, infections of burn, catheter infections and infections of heart valve. Owing to mass usage of antibiotic agents, P. aeruginosa has shown multi-drug resistance (MDR) that always causes failure in clinical therapy. Bacterial phage, Quorum sensing (QS) and biofilm of P.aeruginosa are the focus of many researchers. This work is to try to illuminate their relationships. 1. Bacterial phage of P.aeruginosa:A coliphage PPA5 with host for Pseudomonas aeruginosa was isolated from the wastewater of Huaxi Medical Center, Sichuan University, and some basic biological properties were identified. The host strain of PPA5 was a cipfloxacin resistance strain PA0315 (MIC 64mg/L) came from Huaxi Hospital, Sichuan University. Electron microscopy showed the purified PPA5 particles had an isometrie head about 80-90nm and 130-140nm tail. The optimal MOI of PPA5 was 0.1. One-step curve of the phage showed that the latent period was about 90 min and the burst period 120 min. The average burst size was about 31 phage particles per infected bacterial cell. The genome of PPA5 was about 35-45kb and constructed by a circle dsDNA.