title: Mycobacterium avium complex organisms predominantly colonize in the bathtub inlets of patients' bathrooms.
abstract: Medical treatment of pulmonary Mycobacterium avium complex (MAC) disease does not always provide curative effects and is frequently hampered by recurrence. This suggests the presence of a reservoir for MAC in the environment surrounding patients. We previously reported the recovery of MAC isolates from the residential bathrooms of outpatients. In the present study, to ascertain the colonizing sites and the possibility of an MAC reservoir in the bathrooms of patients, we tested the recovery and the genetic diversity of MAC isolates from 6 sites of specimens, including 2 additional sampling sites, inside the showerhead and the bathtub inlet, in the residential bathrooms of patients with pulmonary MAC disease. MAC isolates were recovered from 15 out of the 29 bathrooms (52%), including specimens from 14 bathtub inlets and 3 showerheads. Nearly half of these bathrooms (7/15) contained MAC strains that were identical or similar to their respective clinical isolates Additionally, in 5 out of 15 bathrooms, polyclonal colonization was revealed by pulsed-field gel electrophoresis. The results imply that colonization of MAC organisms in the bathrooms of MAC patients occurs predominantly in the bathtub inlets, and there is thus a risk of infection and/or reinfection for patients via use of the bathtub and other sites in the bathroom.
authors.affiliation: Toneyama Institute for Tuberculosis Research Osaka City University Medical School, Osaka 560-8552, Japan. nishiuchi@med.osaka-cu.ac.jp
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Nishiuchi
authors.forename: Aki
authors.initials: A
authors.lastname: Tamura
authors.forename: Seigo
authors.initials: S
authors.lastname: Kitada
authors.forename: Takahiro
authors.initials: T
authors.lastname: Taguri
authors.forename: Sohkichi
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tateishi
authors.forename: Mamiko
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Ozeki
authors.forename: Narumi
authors.initials: N
authors.lastname: Matsumura
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ogura
authors.forename: Ryoji
authors.initials: R
authors.lastname: Maekura
mesh_terms: D001494:Baths; D018441:Biofilms; D016009:Chi-Square Distribution; D016521:Electrophoresis, Gel, Pulsed-Field; D004866:Equipment Contamination; D006761:Hospitals; D006797:Housekeeping, Hospital; D006801:Humans; D007564:Japan; D015269:Mycobacterium avium Complex / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D015270:Mycobacterium avium-intracellulare Infection / Q000382:microbiology; D010362:Patients' Rooms; D012498:Sanitary Engineering; D018709:Statistics, Nonparametric; D014871:Water Microbiology