Epidemiology of Pseudomonas aeruginosa in Intensive Care Unit and Otolaryngology Department of a Tunisian hospital

Ninety four clinical isolates of Pseudomonas aeruginosa cultured from patients admitted to the Intensive Care Unit (ICU) (N= 37) and Otolaryngology (ORL) (N= 57) during one year (2001-2002) at the Rabta hospital (Tunisia) have been investigated by using serotyping, pyocintyping, drug susceptibility, M13-PCR and PFGE typing. Result shown that most of the isolates at the ICU belonged to serotype O:12 (11/37) that showed high resistance to commonly used antimicrobials (β-lactamins, aminosids, and quinolone) and a predominance for pyocinotype P10. Despite the frequent occurrence of identical serotypes and pyocinotypes, most of the isolates represent unique RAPD-M13 genotype (88/94). PFGE typing detected three distinct clusters amongst the O12 isolates, suggesting a clonal relatedness among multiresistant O12 isolates. This study illustrates the importance of phenotypic and genotypic epidemiological surveillance of predominant O12 serotype clones in such service in local hospital.   Key words: Pseudomonas aeruginosa, epidemiology, clonal diffusion, multidrug resistance.