EPIDEMIOLOGIC TYPING OF UROPATHOGENIC PSEUDOMONAS-AERUGINOSA STRAINS FROM HOSPITALIZED-PATIENTS

One hundred and twenty-one clinical isolates of Pseudomonas aeruginosa from patients with hospital-acquired urinary tract infections (UTIs) were studied to determine their major epidemiological markers, including API 20NE profile, O-serotype, pyocin type, phage type, lysogenic state and antibiotic susceptibility. Serotypes O4, O12, O11, O6 and O5 were found with a high frequency, accounting respectively for 23·9%, 23·1%, 12·3%, 8·2% and 5·7% of isolates. Pyocin type 10 was most common (32·2%) followed by types 1 (10·7%), 33 (7·5%) and 105 (4·1%); subtype h was predominant being characteristic of 34·7% of isolates. Most of the strains (69·4%) were either not phage typable or sensitive to phages 68 and 119x. Resistance to gentamicin, tobramycin, amikacin, imipenem and ciprofloxacin was more frequent among strains belonging to serotype O12. The O-serotypes were combined with API 20NE profiles, pyocin and phage types, lysogenic states and antibiotic resistance in order to identify epidemiologically related clones. Within predominant serotypes-O4 and O12-most strains displayed similar but not identical type characteristics, whereas other serotypes were less homogeneous. Our results support the concept that a combination of current typing techniques allows the identification of epidemiologically related P. aeruginosa isolates. © 1991.