Water characteristics associated with the occurrence of Legionella pneumophila in dental units.

Autor: Zanetti, Franca, Stampi, Serena, De Luca, Giovanna, Fateh-Moghadam, Pirous, Bucci Sabattini, Maria Antonietta, Checchi, Luigi
Předmět:
Zdroj: European Journal of Oral Sciences; Feb2000, Vol. 108 Issue 1, p22-28, 7p, 4 Charts
Abstrakt: 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 the 101 (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. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index