The prevalence of Shiga toxin-producing Escherichia coli in cattle and sheep in the lower North Island, New Zealand.
OBJECTIVE
To genotype Escherichia coli cultured from the faeces of healthy cattle and sheep in the lower North Island, in order to investigate the possible role of ruminants as a reservoir for Shiga toxin-producing E. coli (STEC) in New Zealand.


METHODS
A total of 952 strains of E. coli were isolated on selective media, from faecal swabs from 319 animals (187 cattle and 132 sheep) from four sites in the Manawatu and Rangitikei regions of New Zealand. A multiplex polymerase chain reaction (PCR) was used to genotype the E. coli isolates, using amplification of Shiga toxin genes (stx1 and stx2) and the E. coli attaching and effacing gene (eae).


RESULTS
Isolates of E. coli were cultured from swabs from 178/187 (95.2%) cattle and all 132 (100%) sheep. Ninety-nine (10.4%) of the isolates were stx1 only, 83 (8.7%) stx2 only, 33 (3.5%) stx1 and stx2, 23 (2.4%) stx1 and eae, one (0.1%) stx2 and eae, and 115 (12.1%) were eae only. Overall, 51 (27.3%) cattle and 87 (65.9%) sheep were stx-positive, whereas 69 (36.9%) cattle and 36 (27.3%) sheep were eae-positive.


CONCLUSIONS
Both healthy cattle and sheep are asymptomatic reservoirs of STEC in New Zealand. Direct contact with cattle and sheep or consumption of water or foodstuffs contaminated with cattle of sheep faeces may represent a significant source of infection for humans.
Cookson
A L
AL
Rumen Microbial Functional Genomics Group, Metabolism and Microbial Genomics, AgResearch Ltd, Grasslands Research Centre, Private Bag 11008, Palmerston North, New Zealand. adrian.cookson@agresearch.co.nz
Taylor
S C S
SC
Attwood
G T
GT
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology*; D004197:Disease Reservoirs / Q000382:microbiology / Q000662:veterinary; D004926:Escherichia coli / Q000378:metabolism; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D005260:Female; D008297:Male; D009520:New Zealand; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D011634:Public Health; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology*; D022622:Shiga Toxin 1 / Q000096:biosynthesis* / Q000235:genetics; D022641:Shiga Toxin 2 / Q000096:biosynthesis* / Q000235:genetics; D014774:Virulence
D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2