HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Maki, R. P. Articles by Hicks, R. E. Search for Related Content PubMed PubMed Citation Articles by Maki, R. P. Articles by Hicks, R. E. Agricola Articles by Maki, R. P. Articles by Hicks, R. E. Related Collections Municipal Waste Surface Water Quality Ecological Risk Assessment Water Pollution

TECHNICAL REPORTS
Surface Water Quality

Salmonella typhimurium Survival and Viability is Unaltered by Suspended Particles in Freshwater

^a Department of Biology, 10 University Drive, University of Minnesota-Duluth, Duluth, MN 55812
^b South Florida Water Management District, P.O. Box 24680, West Palm Beach, FL 33416-4680

* Corresponding author (rmaki{at}sfwmd.gov)

Received for publication May 21, 2001. Rolling microcosm experiments were conducted to determine whether suspended particles affect the survival and viability of a model pathogen, Salmonella choleraesuis, serotype typhimurium (American Type Culture Collection no. 23567), in a freshwater microbial community. Water from the Duluth, MN harbor of Lake Superior (including native microorganisms) was inoculated with clay, silt, or flocculent organic particles in a range of concentrations and a streptomycin-resistant strain of S. typhimurium. Microcosms (incubated at 20°C) were rolled horizontally (3 rpm) and sampled periodically for total bacteria and total, viable, and culturable S. typhimurium. Total S. typhimurium abundance decreased rapidly in all experiments (8.5–73.1% d^-1). Total bacteria did not decrease as rapidly as the S. typhimurium population in any experiment, suggesting that a microcosm effect was not responsible for the decline in S. typhimurium populations. Loss rates of attached and free cells were similar, indicating that attachment to particles did not enhance the persistence of Salmonella cells beyond our minimum detectable differences. After eight days, only 0.1 to 11.9% of the initial S. typhimurium inocula were detected by direct counts. Suspended particles had a minimal effect on the survival and viability of S. typhimurium; the losses of total, viable, or culturable Salmonella were generally the same across particle treatments and concentrations. Silt and flocculent particles affected loss rates of total and viable S. typhimurium similarly to inorganic particles (clay). It appears unlikely that suspended particles would provide a means for S. typhimurium to persist at hazardous levels in freshwater.

Abbreviations: ANOVA, analysis of variance