Interspecies transmission of microbes and antimicrobial resistance
Antimicrobial resistance, or AMR, happens when bacteria develop the ability to survive drugs like antibiotics that are meant to kill them. This can occur when antibiotics are used too often or not used properly, in both people and animals. Over time, resistant bacteria can spread—between individuals, through contact, or even through food. Studies have shown that animals, including pets and farm animals, can carry and share resistant bacteria with humans. But the transfer can go both ways: people can also pass resistant bacteria to animals. Understanding how microbes and AMR move between species is key to protecting the health of both humans and animals.
Interspecies transmission on the farm setting
Antimicrobials are often used on farms to treat or prevent disease. This means that animals can carry antimicrobial resistant bacteria that can end up in their food product or on the farm environment. This can also lead to colonization or infection of farmers with antimicrobial resistant bacteria. While many studies have found that farmers are more likely than the general public to carry bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), we found that this did not appear to be the case for Clostridoides difficile.
​Clostridioides difficile on dairy farms and potential risk to dairy farm workers
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The ARCS study (Antimicrobial Regimens for Colic Surgery) and the HORIZON study (Horses, Organisms, and Resistance Interconnectivity in ZOonotic Networks) assess the changes in horses' microbiome and resistome (collection of antimicrobial resistance genes) over the course of hospitalization as well as that of their owners following hospital discharge.
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The AMR-GALLOPS study (AntiMicrobial Resistance in Goats, Alpacas, LLamas, Or Pigs and Sheep) investigates the same question in some of our more "non-traditional" hospital patients.
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The STRIVE (Studying Transmission of Resistance In Veterinary Environments) examines colonization of veterinary personnel (veterinarians, technicians/nurses) with antimicrobial resistant bacteria to identify which factors affect the degree to which veterinary professionals carry these organisms.
Interspecies transmission in the hospital setting
In the veterinary hospital, animals are often treated with antibiotics and at risk of hospital-acquired ("nosocomial") infections. We have several ongoing studies investigating the extent to which hospitalized animals pick up antimicrobial resistant bacteria and whether they then pass them on to their owners/caretakers.
Interspecies transmission in the home setting
Sharing of bacteria between pets and their owners in the home setting has been well-documented for individual pathogens such as Campylobacter, Staphylococcus, or E. coli. We've demonstrated that such interspecies transfer occurs only rarely for C. difficile, and often in cases where there was an underlying predisposition (e.g., the person or the animal was recently treated with antibiotics or immunocompromised). We are also investigating the extent to which pets and owners exchange healthy microbiota and antimicrobial resistant bacteria when taking antibiotics in the REMBRANDT study (REcovery of the MicroBiota fRom ANtibiotics for Dental implanTs). This study is ongoing, but preliminary results suggest that owners' and pets' microbiomes more closely resemble each other (potentially due to sharing of microbiota) when the owner's microbiome is disrupted by antibiotics.
Genetic and phenotypic characteristics of Clostridium (Clostridioides) difficile
from canine, bovine, and pediatric populations
Infrequent intrahousehold transmission of Clostridioides difficile between pet
