ABSTRACT
Outbreaks of infection with gram-negative bacteria (GNB) have been linked to hospital water. We sought to determine whether point-of-use (POU) water filtration might result in decreased risk of infection in hospitalized bone marrow transplant (BMT) recipients in the absence of any recognized outbreak. Unfiltered water was sampled from taps in the BMT unit of a major US teaching hospital, and cultured at a reference laboratory. POU bacterial-retentive filters (0.2 mum) were installed throughout the unit, and replaced every 14 days. Infection rates were tracked over a 9-month period, and compared with rates for a 16-month period before POU filtration. Unfiltered water samples from 50% (2 of 4) outlets sampled grew P. aeruginosa (2 of 4) and Stenotrophomonas maltophilia (1 of 4). Clinical infection rates in the unit were significantly reduced from 1.4 total and 0.4 GNB infections per 100 patient days in the period before POU filtration to 0.18 total and 0.09 GNB infections per 100 patient days (P=0.0068 and 0.0431, respectively) in the 9-month period for which filters were in place. Infections during the POU filtration period were due to non-waterborne organisms. Point-of-use (POU) water filtration may significantly reduce infection rates in BMT recipients in the absence of any recognized outbreak.
Subject(s)
Bone Marrow Transplantation/adverse effects , Cross Infection/epidemiology , Filtration/methods , Gram-Negative Bacteria/isolation & purification , Gram-Negative Bacterial Infections/epidemiology , Hospital Units , Water Purification/methods , Cross Infection/microbiology , Cross Infection/prevention & control , Fresh Water/microbiology , Gram-Negative Bacterial Infections/microbiology , Gram-Negative Bacterial Infections/prevention & control , Hospitals, Teaching , Humans , Incidence , Pennsylvania , Water SupplyABSTRACT
Clinical isolates of Aeromonas hydrophila, A. sobria, and A. caviae whose fatty acid content had been analyzed by gas-liquid chromatography (GLC) displayed the following qualitatively similar GLC profiles: 12:0, 14:0, 15:0, 16:0, 17:0, 18:0, 16:1, 18:1, a-15:0, a-17:0, and 3-OH 14:0. The 16:0/17:0 area-percentage ratio separated the clinical aeromonads in accordance with their species designations. Aeromonads treated with subminimal inhibitory concentrations of the antibiotic cerulenin displayed the following altered qualitative fatty acid GLC profiles: 12:0, 14:0, 16:0, 18:0, 16:1, 18:1, and 3-OH 14:0. Cerulenin-treated cells failed to reproducibly display detectable levels of all odd-numbered-carbon-chain-length fatty acids observed in untreated cells. Cerulenin-treated cells also exhibited overall increases in 14:0 and 3-OH 14:0 and a decrease in total unsaturated fatty acid content.
Subject(s)
Aeromonas/analysis , Fatty Acids/analysis , Aeromonas/drug effects , Cerulenin/pharmacology , Chromatography, Gas , EstersABSTRACT
Susceptibility results obtained with individualized MIC strips (MICRO-MIC) agreed with the standard microdilution broth method at a level of 96% or greater for each of the 10 antimicrobial agents tested.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Microbial Sensitivity Tests/methods , Evaluation Studies as Topic , Reagent StripsABSTRACT
Gas-liquid chromatographic analysis of fatty acid methyl esters obtained from clinical isolates of Aeromonas hydrophila, A. sobria, and A. caviae revealed the presence of two hydroxy fatty acid species, 3-OH 12:0 and 3-OH 14:0.
