Identification of bacteria in drinking and purified water during the monitoring of a typical water purification system.
BACKGROUND
A typical purification system that provides purified water which meets ionic and organic chemical standards, must be protected from microbial proliferation to minimize cross-contamination for use in cleaning and preparations in pharmaceutical industries and in health environments.


METHODS
Samples of water were taken directly from the public distribution water tank at twelve different stages of a typical purification system were analyzed for the identification of isolated bacteria. Two miniature kits were used: (i) identification system (api 20 NE, Bio-Mérieux) for non-enteric and non-fermenting gram-negative rods; and (ii) identification system (BBL crystal, Becton and Dickson) for enteric and non-fermenting gram-negative rods. The efficiency of the chemical sanitizers used in the stages of the system, over the isolated and identified bacteria in the sampling water, was evaluated by the minimum inhibitory concentration (MIC) method.


RESULTS
The 78 isolated colonies were identified as the following bacteria genera: Pseudomonas, Flavobacterium and Acinetobacter. According to the miniature kits used in the identification, there was a prevalence of isolation of P. aeruginosa 32.05%, P. picketti (Ralstonia picketti) 23.08%, P. vesiculares 12.82%,P. diminuta 11.54%, F. aureum 6.42%, P. fluorescens 5.13%, A. lwoffi 2.56%, P. putida 2.56%, P. alcaligenes 1.28%, P. paucimobilis 1.28%, and F. multivorum 1.28%.


CONCLUSIONS
We found that research was required for the identification of gram-negative non-fermenting bacteria, which were isolated from drinking water and water purification systems, since Pseudomonas genera represents opportunistic pathogens which disperse and adhere easily to surfaces, forming a biofilm which interferes with the cleaning and disinfection procedures in hospital and industrial environments.
Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
Vessoni Thereza Christina
VT
Penna
Silva Alzira Maria
SA
Martins
Priscila Gava
PG
Mazzola
D000150:Acinetobacter / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D004203:Disinfection; D004345:Drug Industry; D005374:Filtration; D005417:Flavobacterium / Q000302:isolation & purification; D016946:Gram-Negative Aerobic Rods and Cocci / Q000145:classification / Q000302:isolation & purification*; D006761:Hospitals; D006801:Humans; D017053:Infection Control / Q000295:instrumentation / Q000379:methods; D011549:Pseudomonas / Q000302:isolation & purification; D012498:Sanitary Engineering / Q000295:instrumentation; D014871:Water Microbiology; D018508:Water Purification / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D014881:Water Supply / Q000592:standards*