Paws and Clean: An Investigation of Bacteria on a Dog's Paws Using Genomic Sequencing and Functional Testing

Goal

Using genomic sequencing and biochemical testing, this study explores the characteristics of the bacteria recovered from a dog's paws as well as the effect of a period of `antibacterial' cleansing.

Background

Companion animals such as dogs live in close proximity to humans and can harbour bacteria on their paws that may present a risk of zoonotic infection (Gay et al., 2014). On the other hand, exposure to dogs and farm animals during the first year of life reduces the risk of asthma in children at age of 6 years (Fall et al., 2015) and may point to a beneficial function for these microbes. Interventions by owners, such as the use of antibiotics and also `antimicrobial' cleaning agents aim to reduce the concentrations of microbes on companion animals and in the home environment. However, an unintended consequence of the extended use of these substances may be an increase in antimicrobial resistance.

Method

A series of paw swab samples were collected from a companion dog before walking, after walking and after cleaning. Collection was repeated after 10 days of regular cleaning using antimicrobial wipes, in order to assess any effect on the bacterial profile. Samples were transferred onto LB agar plates and incubated overnight and a representative number of bacterial colonies chosen for antibiotic susceptibility testing. Selected colonies were then streaked onto LB plates and purified isolates prepared for DNA extraction and shotgun sequencing via the Illumina MiSeq platform. Assembled genomic sequences were analysed using a range of bioinformatics tools to determine potential virulence and to identify antibiotic resistance genes.

Reference

Fall, T., Lundholm, C., Örtqvist, A.K., Fall, K., Fang, F., Hedhammar, A., Kämpe, O., Ingelsson, E., Almqvist, C. (2015) Early Exposure to Dogs and Farm Animals and the Risk of Childhood Asthma. JAMA Pediatrics, 169(11): e153219. doi: 10.1001/jamapediatrics.2015.3219

Gay, N, Soupé-Gilbert, M.E., Goarant, C. (2014) Though not reservoirs, dogs might transmit Leptospira in New Caledonia. International Journal of Environmental Research and Public Health , 11(4), 4316-4325. doi: 10.3390/ijerph110404316

Acknowledgements

This project was funded under the ISF Shuyuan Research Program.