The Canadian study examined fecal dropping from rats, sampled at an Abbotsford poultry farm (in British Columbia.) The majority of the samples contained a stain of Escherichia coli known to infect poultry. The same strain of the bacterium has also been associated with human infections.
When captured rats were examined, the same bacterial strain was recovered from fur and appendages on around one quarter of the trapped rodents. Upon further analysis the bacterium was found to be resistant to a number of antimicrobials (“multi-drug resistant.”)
Other examinations found the same bacterium — as identified through molecular biology techniques — on chickens. The point of origin was the rats. Comparisons were done to examine the gut microbiome of rural and urban rats. Here significant differences were found, with the rural rats having several different types of bacteria. To an extent, the rural rat gut bore close similarities to the intestinal microbiota of poultry.
Urban rats pose a different risk. With these rodents, bacteria that pose a different risk to human health were more commonly isolated, including methicillin-resistant Staphylococcus aureus. These were isolated from Vancouver’s Downtown Eastside.
The extent of isolation of the pathogen led one of the researchers to describe rats as a type of “pathogen sponge,” in terms of absorbing disease causing organisms and spreading these around the environment.
Further research will be performed to ascertain the extent of other pathogens being carried and spread around by the rats. To an extent, a finding like this is not new (look at the causative factors behind the medieval ‘black death’); however, they provide a salutary reminder about the risk posed by rats in close proximity to farms and local communities. The findings reinforce the need to address rat infestations in close proximity to farms, as well as towns and cities.
The study was carried out by scientists employed at the University of British Columbia School of Population and Public Health. The findings will shortly be published in the Journal of Wildlife Diseases, in a paper which is titled “Avian pathogenic and antibiotic resistant E. coli in wild rats.”
