[Show abstract][Hide abstract] ABSTRACT: Members of the Fusarium group were recently detected in water distribution systems of several hospitals in the world. An epidemiological investigation was conducted over 2 years in hospital buildings in Dijon and Nancy (France) and in non-hospital buildings in Dijon. The fungi were detected only within the water distribution systems of the hospital buildings and also, but at very low concentrations, in the urban water network of Nancy. All fungi were identified as Fusarium oxysporum species complex (FOSC) and Fusariumdimerum species complex (FDSC) by sequencing part of the translation elongation factor 1-alpha (TEF-1α) gene. Very low diversity was found in each complex, suggesting the existence of a clonal population for each. Density and heterogeneous distributions according to buildings and variability over time were explained by episodic detachments of parts of the colony from biofilms in the pipes. Isolates of these waterborne populations as well as soilborne isolates were tested for their ability to grow in liquid medium in the presence of increasing concentrations of sodium hypochlorite, copper sulfate, anti-corrosion pipe coating, at various temperatures (4°–42 °C) and on agar medium with amphotericin B and voriconazole. The waterborne isolates tolerated higher sodium hypochlorite and copper sulfate concentrations and temperatures than did soilborne isolates but did not show any specific resistance to fungicides. In addition, unlike waterborne isolates, soilborne isolates did not survive in water even supplemented with glucose, while the former developed in the soil as well as soilborne isolates.
[Show abstract][Hide abstract] ABSTRACT: Dijon Hospital is a French tertiary care institution undergoing major renovation, and different microbiological controls revealed the presence of Fusarium spp. in the water distribution system. Because some Fusarium spp. can cause life-threatening opportunistic infections in immunocompromised patients, an 8-month survey was conducted in two hospital sites in order to evaluate the prevalence of the fungi in the water system. In 2 units of one hospital site, 100% of the samples of tap-water were positive, with high concentrations of Fusarium spp. (up to 10(5)cfu/L). In the second hospital site, 94% of samples were positive, but generally with lower concentrations. The analysis of translation elongation factor 1α (TEF) sequences of 146 isolates revealed the presence of two different Fusarium species: F. oxysporum was detected in all units explored of both hospital sites, and F. dimerum only in one unit of one hospital site. For both species, we suggest that the fungi discovered could be particularly adapted to an aquatic environment.
Full-text · Article · Dec 2011 · International journal of hygiene and environmental health