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Title: Legionella in Puerto Rico cooling towers

Technical Report ·
DOI:https://doi.org/10.2172/353374· OSTI ID:353374
; ;  [1]
  1. Univ. of Puerto Rico, Rio Piedras (Puerto Rico)

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, Puerto Rico were assayed for various species and serogroups of Legionella spp. using direct immunofluorescence. Several water quality parameters were also measured with each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila (1-6), L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species, reaching 10{sup 5} cells/ml, within the range that is considered potentially pathogenic to humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (AODC), were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems, and without continuous biocide treatment may reach densities that present a health risk.

Research Organization:
E.I. du Pont de Nemours and Co., Savannah River Lab., Aiken, SC (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States); National Inst. of Health, Bethesda, MD (United States); National Insts. of Health, Bethesda, MD (United States)
DOE Contract Number:
AC09-89SR18035; AC09-76SR00001
OSTI ID:
353374
Report Number(s):
DP-MS-88-9; ON: DE99002906; CNN: Grant R/LR-08-87-THA1; Grant RR-2657; Grant RR-8102; TRN: AHC29923%%207
Resource Relation:
Other Information: PBD: [1988]
Country of Publication:
United States
Language:
English