Healthy Cats, Dogs Capable of Transmitting Drug-Resistant Microbes to Humans

A recent study found that healthy cats and dogs can transmit multi-drug-resistant bacteria to humans.

Multidrug-resistant organisms, also known as MDROs, are bacteria that can resist drug treatment from more than one kind of antibiotic. These types of bacteria slowly evolve and become even more resistant to the drug people use to eliminate them.

Drug-Resistant Microbes in Pets

A scientific estimate noted that these MDROs caused 1.3 million deaths; nearly five million deaths worldwide in 2019 were linked to microbes. The latest research, which has yet to be presented at this week's European Congress of Clinical Microbiology and Infectious Diseases in Copenhagen, argues that the chances of cross-infection are relatively low.

The study was led by Dr. Carolin Hackmann from Charite University Hospital in Berlin and involved more than 2,800 hospitalized patients and their accompanying pets. Animals that harbor a number of these bacteria and microorganisms have become a serious concern among the scientific community worldwide, as per Geo News.

To conduct a study on the situation, researchers collected samples of hospitalized patients and their animal companions living inside their homes. The team's genetic sequencing method allowed them to identify the genes that cause drug resistance, and they found that 30% of the patients had such bacteria.

The study found that cat owners had a 9% positivity rate as opposed to dog owners, who had a higher rate of 11%. The owners were also asked to send the samples, and the researchers found that in four cases, the organisms of the same species were in both pets and owners with the same levels of drug resistance.

Hackmann said that despite the relatively low level of sharing between patients and their pets, carriers are capable of shedding the types of bacteria into their environment for several months. These can be a significant source of infection for other, more vulnerable people, including those with weaker immune systems or the very young and old.

Observational Study

In a statement, Hackmann added that the team's findings verify that the sharing of multidrug-resistant organisms between people and their pets is entirely possible. The researchers focused on the most common superbugs found in hospital patients, including methicillin-resistant Staphylococcus aureus (MRSA), according to SciTechDaily.

They also identified vancomycin-resistant enterococci (VRE), 3rd generation cephalosporin-resistant Enterobacterales (3GCRE), as well as carbapenem-resistant Enterobacterales (CRE). The latter is resistant to several antibiotics, including penicillin and cephalosporins.

The team noted that their study was observational and cannot prove whether close contact with pets is causing colonization with MDROs. However, it suggests the possibility of co-carriage but does not detail a specific transfer direction.

The situation comes as a separate team from the University of Calgary Faculty of Veterinary Medicine (UCVM) published a collaborative study showing parasitic hookworms resist one of the most critical drugs humans have and are widespread in pet dogs throughout the United States, said UCalgary.