Sheref Gawish1, Aleya Abbass2, Amani Abaza2. 1. MSc Microbiology, Microbiology Department, High Institute of Public Health, Alexandria University, 165 El Horreya Avenue, Alexandria, Egypt. 2. PhD, Professor of Microbiology, Microbiology Department, High Institute of Public Health, Alexandria University, 165 El Horreya Avenue, Alexandria, Egypt.
Abstract
INTRODUCTION: Dental unit waterlines (DUWLs) are notorious for being contaminated with different bacterial species including the opportunistic pathogen Pseudomonas aeruginosa which poses a risk to patients and professionals. This work aimed at studying the occurrence and biofilm-forming ability (BFA) of P. aeruginosa in the output of DUWLs in a dental center in Egypt. METHODS: Water samples were collected from the outlets of the high-speed hand piece, the air/water syringe and the cup filler waterlines. Bacteriological analysis included heterotrophic plate count (HPC), isolation and identification of P. aeruginosa and determination of the antimicrobial susceptibility and the BFA of the isolates by tissue culture plate (TCP) method and tube method (TM). RESULTS: The average concentration of HPC bacteria in the output of the 3 DUWLs was 2.9×104 CFU/μL where 88.3% of the samples exceeded the Egyptian standards for drinking water (<50 CFU L). P. aeruginosa was isolated from nine cup filler samples (which had a water source different from the other waterlines). The isolates were sensitive to all tested antimicrobials. Of these nine isolates, 6, 5 and 4 were positive for BFA by TCP, modified TCP and TM, respectively. CONCLUSIONS: More stringent measures are required to ensure safer dental water; as the majority of studied samples exceeded the required HPC bacterial limit and P. aeruginosa isolates were detected. P. aeruginosa isolates from DUWLs may not be as resistant to antibiotics as what is reported in the literature about clinical isolates. Some P. aeruginosa isolates can colonize DUWLs despite their inability to form biofilms in experimental testing.
INTRODUCTION: Dental unit waterlines (DUWLs) are notorious for being contaminated with different bacterial species including the opportunistic pathogen Pseudomonas aeruginosa which poses a risk to patients and professionals. This work aimed at studying the occurrence and biofilm-forming ability (BFA) of P. aeruginosa in the output of DUWLs in a dental center in Egypt. METHODS: Water samples were collected from the outlets of the high-speed hand piece, the air/water syringe and the cup filler waterlines. Bacteriological analysis included heterotrophic plate count (HPC), isolation and identification of P. aeruginosa and determination of the antimicrobial susceptibility and the BFA of the isolates by tissue culture plate (TCP) method and tube method (TM). RESULTS: The average concentration of HPC bacteria in the output of the 3 DUWLs was 2.9×104 CFU/μL where 88.3% of the samples exceeded the Egyptian standards for drinking water (<50 CFU L). P. aeruginosa was isolated from nine cup filler samples (which had a water source different from the other waterlines). The isolates were sensitive to all tested antimicrobials. Of these nine isolates, 6, 5 and 4 were positive for BFA by TCP, modified TCP and TM, respectively. CONCLUSIONS: More stringent measures are required to ensure safer dental water; as the majority of studied samples exceeded the required HPC bacterial limit and P. aeruginosa isolates were detected. P. aeruginosa isolates from DUWLs may not be as resistant to antibiotics as what is reported in the literature about clinical isolates. Some P. aeruginosa isolates can colonize DUWLs despite their inability to form biofilms in experimental testing.
Entities:
Keywords:
Pseudomonas aeruginosa; biofilm; dental unit waterlines
Authors: Luigi Aprea; Lucia Cannova; Alberto Firenze; Maria S Bivona; Emanuele Amodio; Nino Romano Journal: J Oral Sci Date: 2010-12 Impact factor: 1.556
Authors: Cesira Pasquarella; Licia Veronesi; Christian Napoli; Paolo Castiglia; Giorgio Liguori; Rolando Rizzetto; Ida Torre; Elena Righi; Patrizia Farruggia; Marina Tesauro; Maria V Torregrossa; Maria T Montagna; Maria E Colucci; Francesca Gallè; Maria D Masia; Laura Strohmenger; Margherita Bergomi; Carola Tinteri; Manuela Panico; Francesca Pennino; Lucia Cannova; Marialuisa Tanzi Journal: Sci Total Environ Date: 2012-02-13 Impact factor: 7.963