title: Common RAPD pattern of Pseudomonas aeruginosa from patients and tap water in a medical intensive care unit.
abstract: The epidemiology of Pseudomonas aeruginosa infections and colonizations was studied prospectively on a 12-bed medical intensive care unit. Patients were monitored for P. aeruginosa colonization by performing throat swabs or tracheal aspirates on admission and weekly thereafter over a period of 6 months. Cultures of possibly infected sites were taken as clinically indicated. Water samples from all patient care-related tap water outlets were collected in 2-weekly intervals and examined for the presence of P. aeruginosa. Strains isolated from patients and water samples were analysed by serotyping and random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) typing. During the 6-month period, 60 of 143 (42%) water samples contained P. aeruginosa at various levels ranging from 1 to >100 colony-forming units per 100ml sample. Genotypically, water samples contained 8 different clonotypes. Nine patients had infections due to P. aeruginosa and 7 patients were colonized. Isolates from patients showed a similar distribution of genotypes as did tap water isolates, and strains of identical genotype as patient strains had been isolated previously from tap water outlets in 8 out of 16 (50%) infection or colonization episodes. However, patients also harboured strains not previously isolated from tap water. Thus, in addition to tap water, other environmental or unknown reservoirs appeared to play a role for the epidemiology of P. aeruginosa infections on this ward. However, because tap water played a significant role for strain transmissions, we conclude that intensified water site care is justified.
authors.affiliation: Section of Hospital Hygiene, Department of Medical Microbiology and Hygiene, Ulm University Hospital, Ulm, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Trautmann
authors.forename: Cindy
authors.initials: C
authors.lastname: Bauer
authors.forename: Christian
authors.initials: C
authors.lastname: Schumann
authors.forename: Philipp
authors.initials: P
authors.lastname: Hahn
authors.forename: Martin
authors.initials: M
authors.lastname: Höher
authors.forename: Mathias
authors.initials: M
authors.lastname: Haller
authors.forename: Philipp M
authors.initials: PM
authors.lastname: Lepper
mesh_terms: D003428:Cross Infection / Q000382:microbiology / Q000635:transmission*; D005260:Female; D005838:Genotype; D005858:Germany; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D010614:Pharynx / Q000382:microbiology; D011552:Pseudomonas Infections / Q000382:microbiology / Q000635:transmission*; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D019105:Random Amplified Polymorphic DNA Technique; D014132:Trachea / Q000382:microbiology; D014871:Water Microbiology; D014881:Water Supply