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Water characteristics associated with the occurrence of Legionella pneumophila in dental units
Author(s) -
Zanetti Franca,
Stampi Serena,
De Luca Giovanna,
FatehMoghadam Pirous,
Bucci Sabattini Maria Antonietta,
Checchi Luigi
Publication year - 2000
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1034/j.1600-0722.2000.00763.x
Subject(s) - legionella pneumophila , tap water , legionella , microbiology and biotechnology , chlorine , bacteria , chemistry , biology , veterinary medicine , environmental science , medicine , environmental engineering , genetics , organic chemistry
This study evaluated the incidence of Legionella pneumophila in dental unit water samples and investigated how the occurrence of these bacteria may be related to some physical, chemical and bacteriological characteristics of the water. The samples were taken from the incoming tap water, oral rinsing cup, air–water syringe, ultrasonic scaler, and the turbine of 23 dental units of private and public institutions. Apart from L. pneumophila (serogroup 1 and 3) isolated in 22 out of the101 (21.8%) water samples tested, two other species were found: L. bozemanii and L. dumoffii . The highest densities and frequency of L. pneumophila were observed in the water coming into the units and in the dental units of public institutions. A negative association between L. pneumophila and 36°C and 22°C heterotrophic total plate counts and other Gram‐negative bacteria was found. An inverse association between the concentration of L. pneumophila and water temperature was also observed. The values of pH and total hardness did not show any significant difference in the L. pneumophila ‐positive and ‐negative dental unit waters. Finally, the chemical oxygen demand (COD) and residual chlorine were found to correlate positively with L. pneumophila .