Ecology of Legionella pneumophila within water distribution systems.

摘要: Legionnaires disease hasbeenshowntobethepotable waterdistribution system. We investigated theinfluence ofthenatural microbial population andsediment (scale andorganic particulates) foundinwatersystems as growth-promoting factors forLegionella pneumophila. Ourinvitro experiments showedthat: (i)waterfroma hot-water storage tankreadily supported thesurvival ofL. pneumophila, (ii) theconcentration ofsediment was directly related tothesurvival ofL.pneumophila, (iii) the presenceofenvironmental bacteria improved ofL.pneumophila vianutritional symbiosis, (iv) combination andenvironmental actedsynergistically toimprove and(v)therole inthis synergistic effect determined tobenutritional. Sediment foundtostimulate thegrowthofenvironmental microflora, whichinturnstimulated thegrowthofL. Thesefindings confirm theempiric observations ofthepredilection forgrowth inhot-water tanksanditslocalization tosediment. L.pneumophila occupies an ecological nichewithin potable watersystem, withinterrelationships between sediment, andtemperature. Theprevalence ofLegionella thecausative agentofLegionnaires disease, innatural andmanmade aquatic environments hasbeenwell documented (5,8,9,19, 21,22).Ongoing surveillance forL.pneumophila atthe Pittsburgh Veterans Administration Medical Center hasdemonstrated that thepresence inthehospital system isepidemiologically linked tothe acquisition ofLegionnaires insusceptible, hospitalizedpatients (3,19). Recent experience suggests hospital-acquired notonlycanbetreated but canbeprevented withcontrol measures directed reservoir (2a, 3,10,14). Thesuccess oferadication atwaterdistribution systems will bedetermined by information obtained fromtheanalysis oftheecology ofthis organism within thehabitat ofthewaterdistribution