title: Pseudomonas aeruginosa and Achromobacter sp. clonal selection leads to successive waves of contamination of water in dental care units.
abstract: Dental care unit waterlines (DCUWs) consist of complex networks of thin tubes that facilitate the formation of microbial biofilms. Due to the predilection toward a wet environment, strong adhesion, biofilm formation, and resistance to biocides, Pseudomonas aeruginosa, a major human opportunistic pathogen, is adapted to DCUW colonization. Other nonfermentative Gram-negative bacilli, such as members of the genus Achromobacter, are emerging pathogens found in water networks. We reported the 6.5-year dynamics of bacterial contamination of waterlines in a dental health care center with 61 dental care units (DCUs) connected to the same water supply system. The conditions allowed the selection and the emergence of clones of Achromobacter sp. and P. aeruginosa characterized by multilocus sequence typing, multiplex repetitive elements-based PCR, and restriction fragment length polymorphism in pulsed-field gel electrophoresis, biofilm formation, and antimicrobial susceptibility. One clone of P. aeruginosa and 2 clones of Achromobacter sp. colonized successively all of the DCUWs: the last colonization by P. aeruginosa ST309 led to the closing of the dental care center. Successive dominance of species and clones was linked to biocide treatments. Achromobacter strains were weak biofilm producers compared to P. aeruginosa ST309, but the coculture of P. aeruginosa and Achromobacter enhanced P. aeruginosa ST309 biofilm formation. Intraclonal genomic microevolution was observed in the isolates of P. aeruginosa ST309 collected chronologically and in Achromobacter sp. clone A. The contamination control was achieved by a complete reorganization of the dental health care center by removing the connecting tubes between DCUs.
authors: Université de Montpellier, UMR 5569, Équipe Pathogènes Hydriques Santé Environnements, Montpellier, France.
authors: Fatima
authors: F
authors: Abdouchakour
authors: Université de Montpellier, UMR 5569, Équipe Pathogènes Hydriques Santé Environnements, Montpellier, France.
authors: Chloé
authors: C
authors: Dupont
authors: Université de Montpellier, UMR 5569, Équipe Pathogènes Hydriques Santé Environnements, Montpellier, France Centre Hospitalier Régional Universitaire de Montpellier, Département d'Hygiène Hospitalière, Montpellier, France.
authors: Delphine
authors: D
authors: Grau
authors: Université de Montpellier, UMR 5569, Équipe Pathogènes Hydriques Santé Environnements, Montpellier, France.
authors: Fabien
authors: F
authors: Aujoulat
authors: Centre Hospitalier Régional Universitaire de Montpellier, Centre de Soins Dentaire, Montpellier, France.
authors: Patricia
authors: P
authors: Mournetas
authors: Université de Montpellier, UMR 5569, Équipe Pathogènes Hydriques Santé Environnements, Montpellier, France Centre Hospitalier Régional Universitaire de Montpellier, Laboratoire de Bactériologie, Montpellier, France.
authors: Hélène
authors: H
authors: Marchandin
authors: Université de Montpellier, UMR 5569, Équipe Pathogènes Hydriques Santé Environnements, Montpellier, France Centre Hospitalier Régional Universitaire de Montpellier, Département d'Hygiène Hospitalière, Montpellier, France.
authors: Sylvie
authors: S
authors: Parer
authors: Centre Hospitalier Régional Universitaire de Montpellier, Centre de Soins Dentaire, Montpellier, France.
authors: Philippe
authors: P
authors: Gibert
authors: Centre Hospitalier Régional Universitaire de Montpellier, Centre de Soins Dentaire, Montpellier, France.
authors: Jean
authors: J
authors: Valcarcel
authors: Université de Montpellier, UMR 5569, Équipe Pathogènes Hydriques Santé Environnements, Montpellier, France Centre Hospitalier Régional Universitaire de Montpellier, Département d'Hygiène Hospitalière, Montpellier, France ebilak@univ-montp1.fr.
authors: Estelle
authors: E
authors: Jumas-Bilak
mesh_terms: D042402:Achromobacter / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification*; D016172:DNA Fingerprinting; D003770:Dental Offices; D016521:Electrophoresis, Gel, Pulsed-Field; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D012150:Polymorphism, Restriction Fragment Length; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D014871:Water Microbiology