Survival of Escherichia coli, Enterococci, and Campylobacter spp. in sheep feces on pastures.
The survival of enteric bacteria in 10 freshly collected sheep fecal samples on pastures was measured in each of four seasons. Ten freshly collected feces were placed on pasture, and concentrations of Escherichia coli, enterococci, and Campylobacter spp. were monitored until exhaustion of the fecal samples. In all four seasons, there was an increase in enterococcal concentrations by up to 3 orders of magnitude, with peak concentrations recorded between 11 and 28 days after deposition. E. coli concentrations increased in three out of four seasons by up to 1.5 orders of magnitude, with peak concentrations recorded between 8 and 14 days after deposition. The apparent growth of E. coli and enterococci was strongly influenced by the initial water content of the feces and the moisture gained during periods of rehydration following rainfalls. Conversely, the results suggested that dehydration promoted inactivation. Campylobacter spp. did not grow and were rapidly inactivated at a rate that tended to be faster at higher temperatures. Pulsed-field gel electrophoresis (PFGE) of a selection of Campylobacter spp. suggested that these survival data are applicable to a range of Campylobacter spp., including the most frequently isolated PFGE genotype from sheep in New Zealand, and to genotypes previously observed to cause disease in humans. The results of this study are currently being incorporated into a fecal microbe reservoir model that is designed to assist water managers' abilities to estimate microbial loads on pastures grazed by sheep, including the influence of factors such as rainfall and temperature.
Christchurch Science Centre, Institute of Environmental Science and Research Ltd., P.O. Box 29-181, Christchurch, New Zealand. elaine.moriarty@esr.cri.nz
Elaine M
EM
Moriarty
Margaret L
ML
Mackenzie
Naveena
N
Karki
Lester W
LW
Sinton
D000818:Animals; D002167:Campylobacter / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D016983:Enterococcus / Q000302:isolation & purification* / Q000502:physiology; D004783:Environmental Microbiology; D004926:Escherichia coli / Q000302:isolation & purification* / Q000502:physiology; D005243:Feces / Q000382:microbiology*; D005440:Fluid Therapy; D050296:Microbial Viability; D058889:Molecular Typing; D009520:New Zealand; D012756:Sheep; D013696:Temperature
D004269:DNA, Bacterial
Vet Parasitol. 2007 May 15;146(1-2):17-24
17335979
Commun Dis Intell Q Rep. 2003;27(2):249-57
12926738
J Appl Microbiol. 2005;98(4):980-90
15752345
Epidemiol Infect. 2008 Jun;136(6):739-51
17655782
Lett Appl Microbiol. 2004;38(5):355-9
15059203
Parasitol Res. 2007 Oct;101(5):1443-8
17569991
Appl Environ Microbiol. 1998 Sep;64(9):3166-74
9726855
J Appl Microbiol. 2007 Oct;103(4):977-84
17897201
J Appl Microbiol. 2007 Dec;103(6):2113-21
18045395
J Appl Microbiol. 2007 Oct;103(4):1122-7
17897217
J Clin Microbiol. 2001 May;39(5):1889-94
11326009
J Appl Microbiol. 2004;96(4):750-60
15012813
Lett Appl Microbiol. 2009 Feb;48(2):162-6
19018956
J Clin Microbiol. 2006 Feb;44(2):406-12
16455892
Appl Environ Microbiol. 2008 Oct;74(19):6026-31
18621872
Water Environ Res. 2002 Mar-Apr;74(2):131-5
12043969
Appl Environ Microbiol. 2007 Dec;73(24):7917-25
17951435
Vet Parasitol. 2000 May 17;89(4):269-75
10799840
Appl Environ Microbiol. 2005 Sep;71(9):4992-7
16151078
Int J Food Microbiol. 2005 Mar 1;99(1):99-105
15718033