Dogs and cats can transmit antibiotic-resistant “superbugs” to their owners

Dogs and cats at home could play an important role in the spread of bacteria resistant to antibiotics: this is what emerges from a study presented at the congress of the European Society of Clinical Microbiology and Infectious Diseases (Escmid), held in Barcelona. The authors found evidence of the passage of multidrug-resistant bacteria from sick dogs and cats to their (healthy) owners in Portugal and the United Kingdom: the fear is therefore that domestic animals could act as reservoirs and contribute to the spread of antibiotic resistance (Amr, antimicrobial resistance). The phenomenon has reached worrying levels all over the world. Infections with drug-resistant bacteria kill more than 1.2 million people a year and deaths are expected to reach ten million by 2050; the World Health Organization classifies antibiotic resistance as one of the greatest threats to public health.

Fighting resistance

«Recent research indicates that the transmission of antimicrobial-resistant bacteria between humans and animals, including pets, is critical to maintaining high levels of resistancechallenging the traditional belief that humans are the main carriers of AMR bacteria into the community – he says Juliana Menezesof the Center for Interdisciplinary Research in Animal Health, at the University of Lisbon -.
Understanding and addressing the transmission of AMR bacteria from pets to humans is essential to effectively combat resistanceboth in the human and animal populations.”

E. coli and Klebsiella pneumoniae

Menezes and his colleagues analyzed stool and urine samples and skin swabs from dogs and cats and their owners to detect Enterobacterales (a large family of bacteria that includes E. coli and Klebsiella pneumoniae) resistant to common antibiotics. The study involved 5 cats, 38 dogs and 78 humans from 43 households in Portugal and 22 dogs and 56 humans from 22 households in the UK. All humans were healthy, while domestic animals had skin and soft tissue infections or urinary tract infections.

The strains were the same

In Portugal, it was detected in 3 cats, 21 dogs and 28 owners Enterobacterales producing ESBL/Amp-C (beta-lactamases), i.e. bacteria resistant to third generation cephalosporins. In five families, one with a cat and four with a dog, both the pet and the owner carried ESBL/AmpC-producing bacteria. Genetic analysis showed that the strains were the same, which indicates that the bacteria has passed between pet and owner. Furthermore, in one of the five families, the dog and the owner had the same strain of antibiotic-resistant Klebsiella pneumoniae.

Transmission direction

In the UK, a dog tested positive for two strains of E. coli resistant to third generation cephalosporins, carbapenems and several other families of antibiotics. ESBL/AmpC-producing Enterobacterales were isolated from eight dogs and three owners. In two families, both the dog and the owner were carriers of the same ESBL/AmpC producing bacterium. The direction of the transmission could not be demonstratedhowever in three of the homes in Portugal the timing of positive tests for ESBL/AmpC-producing bacteria strongly suggests that the bacteria were transmitted from pets (two dogs and a cat) to humans.

Wash your hands often

Menezes says: «Our findings highlight the importance of including families who own pets in the national programs monitoring levels of antibiotic resistance. Learning more about resistance in pets would help develop informed and targeted interventions to safeguard animal and human health.” The bacteria can be transmitted between pets and humans through petting, kissing and through handling feces. To prevent transmission, researchers recommend that owners practice good hygiene, including washing their hands after petting their dog or cat and after handling their waste.

Isolate the animal in one room

«When your pet is unwell, consider Isolate it in one room to prevent the spread of bacteria throughout the house and carefully clean the other rooms” concludes Menezes. All dogs and cats analyzed in the study were treated for infections and recovered. The owners had no symptoms and therefore did not require treatment.