Dobrochna Ginter-Kramarczyk

Is water in dental units microbiologically safe

BACKGROUND Water supplied to the dental units must be of sufficient quality. The article presents the results of the microbiological analysis of cold municipal water which flows into a patients disposable mouthwash cup, and demineralized water which flows through a waterline into the tool panel of a dental unit from the tank placed in the water group. MATERIAL AND METHODS In order to assess the degree of purity (impurities) of water used in dental units, 2 series of microbiological tests were carried out in 6 dental surgeries from April to June, 2013. The water samples for microbiological testing were collected into sterile microbiological bottles in accordance with the current methodology. The water for the tests was collected from a sterile cup-filling tap (municipal water) and from an air/water syringe (demineralized water). The bacteria were cultured according to the Polish Standards - PN-EN ISO 6222, PN-EN ISO 9308-1, and PN-EN ISO 16266. RESULTS In the tested samples of water numerous psychrophilic bacteria (max 29 100 CFU/ml) and mesophilic bacteria (max 24 700 CFU/ml), including single coliforms, were found. CONCLUSIONS The results show that water delivered to a dental unit should be periodically tested bacteriologically and in terms of physical and chemical properties. Water systems of dental units should also be periodically disinfected to eliminate bacteria and biofilm.

Biodegradation of Oxyethylated Fatty Alcohols by Bacterium Pseudomonas alcaligenes; AE Biodegradation by Pseudomonas alcaligenes

Abstract Pseudomanas alcaligenes is a Gram-negative soil bacteria which has the potential to degrade hydrocarbons including aromatic compounds. The biodegradation of a representative oxyethylated fatty alcohol by the PA strain under static model conditions with a surfactant as a sole source of organic carbon was investigated. Polydispersal oxyethylated dodecanol C12E10 is biodegraded by the bacterial P. alcaligenes strain of following two alternative pathways: central fission with formation of poly(ethylene glycols) or ω-oxidation of an oxyethylene chain with the formation of carboxyl end group and intermediate aldehyde group. Shorter homologues of polydispersal mixture C12E10 are faster biodegraded and the mixture is enriched with longer homologues.