Slugs: potential novel vectors of Escherichia coli O157.
Field and laboratory studies were performed to determine whether slugs could act as novel vectors for pathogen (e.g., Escherichia coli O157) transfer from animal feces to salad vegetables. Escherichia coli O157 was isolated from 0.21% of field slugs from an Aberdeenshire sheep farm. These isolates carried the verocytotoxin genes (vt1 and vt2) and the attaching and effacing gene (eae), suggesting that they are potentially pathogenic to humans. Strain typing using multilocus variable number tandem repeats analysis showed that slug and sheep isolates were indistinguishable. Laboratory experiments using an E. coli mutant resistant to nalidixic acid showed that the ubiquitous slug species Deroceras reticulatum could carry viable E. coli on its external surface for up to 14 days. Slugs that had been fed E. coli shed viable bacteria in their feces with numbers showing a short but statistically significant linear log decline. Further, it was found that E. coli persisted for up to 3 weeks in excreted slug feces, and hence, we conclude that slugs have the potential to act as novel vectors of E. coli O157.
Sproston
Emma L
EL
School of Biological Sciences, Cruickshank Building, University of Aberdeen, Aberdeen AB24 3UU, United Kingdom.
Macrae
M
M
Ogden
Iain D
ID
Wilson
Michael J
MJ
Strachan
Norval J C
NJ
D018829:Adhesins, Bacterial / Q000235:genetics; D000822:Animal Husbandry; D000818:Animals; D004199:Disease Vectors; D004927:Escherichia coli Infections / Q000382:microbiology / Q000635:transmission*; D019453:Escherichia coli O157 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology; D049851:Gastropoda / Q000382:microbiology*; D018598:Minisatellite Repeats / Q000235:genetics; D012756:Sheep; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2; D022603:Shiga Toxins / Q000235:genetics
D018829:Adhesins, Bacterial; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D022603:Shiga Toxins; C430449:verocytotoxin 2; C073819:eaeA protein, E coli