Spatio-temporal analysis of infra-specific genetic variations among a Pseudomonas aeruginosa water network hospital population: invasion and selection of clonal complexes.
OBJECTIVE
To investigate infra-specific spatio-temporal dynamics of a hospital water network Pseudomonas aeruginosa population. To infer the origin of water network isolates and assess their potential health hazard.


RESULTS
168 P. aeruginosa strains were isolated from tap waters and swabs of tap nozzle aerators of a hospital unit, over 2 years, and from rectal swabs and nosocomial infections. Genetic diversity among this collection was assessed by pulsed field gel electrophoresis of SpeI restricted genomic DNA. Virulence gene sets, biofilm properties, and hypochlorite resistance were analysed. Exactly 68% of the water samples and 74% of the tap nozzle aerators harboured P. aeruginosa. The strains were divided into 22 clonal lineages, with one dominant clone shown to have been involved in a nosocomial infection.


CONCLUSIONS
An important turnover among the P. aeruginosa hospital population was observed. Some clonal lineages were found to persist, spread in the unit, and diversify into clonal complexes. Rectal carriage appeared an important source of contamination of the water network.


CONCLUSIONS
High P. aeruginosa infra-specific population diversity suggested a broad ability in colonizing water networks but persistence analysis indicated a strong selection leading to the emergence of dominant clones.
Lavenir
R
R
Université de Lyon, Lyon, France.
Sanroma
M
M
Gibert
S
S
Crouzet
O
O
Laurent
F
F
Kravtsoff
J
J
Mazoyer
M-A
MA
Cournoyer
B
B
D018441:Biofilms / Q000254:growth & development; D003428:Cross Infection / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D016521:Electrophoresis, Gel, Pulsed-Field; D005602:France / Q000453:epidemiology; D014644:Genetic Variation; D006761:Hospitals; D006801:Humans; D006997:Hypochlorous Acid / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000235:genetics*; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D014871:Water Microbiology; D014881:Water Supply / Q000032:analysis*
D004269:DNA, Bacterial; D016877:Oxidants; D006997:Hypochlorous Acid