Correlations between genotyping and antibiograms of clinical isolates of Pseudomonas aeruginosa from three different south Indian hospitals

Purpose : To compare the molecular relationships and antibiograms of nosocomial isolates of Pseudomonas aeruginosa obtained from three different genres of hospitals located in Southern India, two located at Hyderabad (one private hospital and an ophthalmic hospital) and one in Puducherry (tertiary care teaching hospital). Each of these hospitals, which follow different infection control strategies and various problems associated with it, were investigated. Materials and Methods : Antibiograms generated by disk diffusion susceptibility testing for clinically relevant antibiotics and genotyping through fluorescent amplified fragment length polymorphism analysis (fAFLP) were the tools used in the study. Results: Molecular genotyping revealed a heterogeneous group of unrelated molecular clusters of P. aeruginosa strains having higher resistance that are apparently being endemic throughout the tertiary care teaching hospital. In eye care hospital, only a few distinct strains of P. aeruginosa predominating the study period were shown to be responsible for outbreaks. The third private hospital witnessed a group of resistant and persistent strains that might have clonally originated from a diverse collection of strains. Conclusions : The divergent kind of strains in our study suggests that there may be a direct link between the infection control practices followed in each hospital and kind of strains isolated in that particular setup. The study also emphasizes the need for maintaining infection control practices in hospitals with superior standards, failure of which might result in thriving of persistent P. aeruginosa clones in the hospitals.