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A survey of enteric bacteria and protozoans in fresh bovine faeces on New Zealand dairy farms
Author(s) -
Moriarty E.M.,
Sinton L.W.,
Mackenzie M.L.,
Karki N.,
Wood D.R.
Publication year - 2008
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2008.03939.x
Subject(s) - cryptosporidium , campylobacter , giardia , feces , biology , salmonella , veterinary medicine , microbiology and biotechnology , indicator bacteria , fecal coliform , bacteria , ecology , water quality , medicine , genetics
Aims: To determine the counts and/or prevalence in fresh bovine faeces of Escherichia coli , enterococci, Campylobacter , Salmonella , shiga toxin‐producing E. coli (STEC), Giardia and Cryptosporidium , as inputs to numerical models designed to estimate microbial loadings on pasture grazed by cattle in New Zealand. Methods and Results: In each season over one year, samples of freshly deposited bovine faeces were collected from four New Zealand dairy farms ( n = 155), and enumerated for E. coli , enterococci, Campylobacter , Giardia and Cryptosporidium . They were also tested for the presence of Salmonella and STEC. The overall median bacterial counts (g −1 wet weight) were E. coli – 5·9 × 10 6 ; enterococci – 1·3 × 10 4 ; Campylobacter – 3·9 × 10 5 . All counts were highly variable within and between samplings, and few seasonal or regional patterns emerged. However, mean Campylobacter counts were consistently higher in spring. No Salmonella spp. was detected, and only two samples were positive for STEC. Cryptosporidium and Giardia were isolated from 5·2% and 4·5% of the samples, respectively, yielding low numbers of (oo)cysts (1–25 g −1 and 1–17 g −1 , respectively). Conclusions: Fresh bovine faeces are a significant source of E. coli , enterococci and Campylobacter on New Zealand pastures, although numbers are likely to vary markedly between faecal samples. Significance and Impact of the Study: The study provides the first significant set of indicator and pathogen counts for one of the largest sources of faecal contamination of natural waters in New Zealand, and will be used to model these inputs.