Molecular Study on Relatedness between Clinical and Tap Water Isolates of Pseudomonas aeruginosa in Two Burn Units

Background: The role of tap water as an environmental source of disease causing P. aeruginosa strains was established. Objective: to study the relatedness between clinical and tap water P. aeruginosa isolates in the burn units of two different hospitals. Materials and methods: One hundred and fifty specimens were collected from two burn units of Cairo University Hospital and El Helmeya Military Hospital. These specimens included: 100 pus samples from infected wounds of burned patients, 25 water samples and 25 swabs were taken from hands of medical staff. The samples were cultured and P. aeruginosa isolates were identified as according to standards. The selected colonies were subjected to molecular identification as P. aeruginosa by PCR tesing using specific PAL1 andPAL2 primers, and tested for relatedness by plasmid profiling and protein electrophoresis. Results: All cultures from the hands of the medical personnel were negative for P. aeruginosa. The clinical and water samples yielded 52 P. aeruginosa isolates and only 19 isolates were confirmed by PCR. These isolates were from 16% of total water samples from 15% of total clinical swabs. Half of these isolates harbored plasmids. The phenotypic characteristics of isolates showed that 30% of isolates (from clinical and water specimens) were related. However, molecular studies did not prove any molecular evidence of relatedness between different clinical isolates or between clinical and environmental isolates. Conclusions: P. aeruginosa is the cause of 15% of infections in Egyptian burn units, and contaminates 16% of water samples of these units. The simple use of bacterial protein electrophoresis and plasmid profiling ruled out the relatedness between the clinical and the contaminated water samples. [Mohammed S. Salama, Hala M. Abu Shady, Mohammed M. B. El-Gameal, Mervat G. El Anany and Ghada M. Abd-El-Rehem. Molecular Study on Relatedness between Clinical and Tap Water Isolates of Pseudomonas aeruginosa in Two Burn Units. Life Science Journal. 2012;9(1):662-666] (ISSN: 1097-8135). http://www.lifesciencesite.com. 96