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BACKGROUND: Catheter-associated urinary tract infections (CAUTIs) are the most common infections found in healthcare facilities. Urinary catheters predispose the development of CAUTIs by destroying natural barriers and providing a source for infection and biofilm formation (BF). This study aimed to evaluate probiotic lactic acid bacteria (LAB) as a means of preventing in vitro urinary catheter colonization and BF. METHODS: Cross-sectional screening, followed by an experimental study, was conducted on 120 catheterized patients admitted to the urology department in a tertiary care hospital for 7 months. The isolated and identified uropathogens were tested for their antimicrobial susceptibility patterns by the disk diffusion method according to Clinical and Laboratory Standards Institute recommendations and examined for their ability to produce biofilms using a microtiter plate (MtP) assay. Five LAB (Lactobacillus acidophilus (L. acidophilus), Bifidobacterium bifidum (B. bifidum), L. paracasei, L. pentosus, and L. plantarum) were identified and examined for preventing in vitro colonization and BF of some isolated uropathogens on Foley urinary catheter surfaces. RESULTS: Of the 120 samples collected, 32.5% were found to be associated with CAUTIs. Of isolated organisms, 74.4% were gram-negative bacilli, while gram-positive cocci represented 14%, and only 11.6% were of the Candida species. About two-thirds of isolated uropathogens were biofilm formers. All five probiotic strains had inhibitory effects on the growth of all the uropathogens tested but with varying intensities according to the duration of application after 2, 4, and 6 days. CONCLUSIONS: The prevalence of CAUTIs was high, and the predominant bacterial isolates were gram-negative bacilli. Many of the studied uropathogens were biofilm formers. The bacterial isolates had a higher prevalence of resistance to commonly prescribed antimicrobial agents. Probiotics have the potential to prevent in vitro urinary catheter colonization and inhibit BF. Pre-coating urinary catheters with probiotics is recommended after ensuring the safety of probiotics' use in vivo by carrying out further large-scale studies.
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INTRODUCTION: Monitoring the microbial quality of water in dental unit waterlines is an important part of infection control measures carried out in dental clinics. Fungal contamination of such waterlines has not been extensively studied, compared with bacterial contamination. This study aimed at assessing the magnitude and risk factors for fungal contamination of dental unit waterlines. METHODOLOGY: This cross-sectional study included 82 dental units, randomly collected from 3 private clinics and 8 governmental hospitals in Alexandria, Egypt. A total of 204 water samples from dental unit waterlines output were membrane-filtered and cultured for fungal enumeration and species identification. The biofilm forming-ability was assessed for the most prevalent fungal species. The acceptability of samples was determined according to the Swedish drinking water guidelines. RESULTS: The acceptability of samples was 89.7%. The most common mould was Aspergillus flavus, while Candida spp. was the most common yeast (10 isolates), with unusual predominance of Candida dubliniensis (9 isolates). All isolates of Aspergillus flavus and Candida dubliniensis were biofilm-formers. The risk factors for fungal contamination of dental unit waterlines included: dental specialty (p = 0.042), time of sample collection (p < 0.001), older age of dental unit (p < 0.001) and use of 5-15% of sodium hypochlorite. CONCLUSIONS: The presence of biofilm-forming fungi in dental unit waterlines is a potential hazard, even when samples have acceptable levels of fungal counts. Risk factors for contamination are numerous and should be addressed.