Ruminations: From China (Again) With Love

"If bacteria resistant to all drugs acquire this resistance gene, they would become untreatable, and that's a scenario we must avoid at all costs."
"The trend for feeding dogs raw food may be fuelling the spread of antibiotic resistant-bacteria."
"We know that the over-use of antibiotics drives resistance and it is vital that they are used responsibly, not just in medicine but also in veterinary medicine and in farming."
Dr.Juliana Menezes, University of Lisbon, Spain

"The close contact of humans with dogs and the commercialization of the studied brands in different countries poses an international public health risk."
"European authorities must raise awareness about the potential health risks when feeding raw diets to pets and the manufacture of dog food, including ingredient selection and hygiene practices, must be reviewed."
Researcher in biomedical science, Ana Freitas, University of Porto, Portugal

New research could point to raw dog food as a source of antibiotic-resistant bacteria Cristina Vega RHOR AFP/File

In 2015 the first case of a potentially untreatable superbug transitioning from dogs to humans was reported in China. Colistin, a last-chance antibiotic to treat and defeat bacterial infections resistant to any other drugs, is also resistant in the presence of the mer-1 gene. The mer-1 gene was found to be present in a small number of both dogs and humans where bacteria including mer-1 were present. In China, dogs and cats are more likely to be eaten than kept as pets.

Scientists now warn of a pending "nightmare scenario" with the discovery of the gene transmitted to people via their companion dogs, the bacterium known to be resistant to the powerful antibiotic used in medicine as a last resort to save peoples' lives. New research published by a team of scientists from the University of Lisbon has alerted the world of medical science in a presentation at the European Congress of Clinical Microbiology and Infectious Diseases conference.

What truly distinguishes the study is that it is recognized as one of the first reports that mer-1 has been found in humans. Raw dog food has been recognized as a major source of antibiotic resistant bacteria. As well, in analyzing a range of dog food, researchers at the University of Porto found that 54 percent of the food contained Enterococci bacteria, 40 percent of which was resistant to a number of antibiotics.

Antimicrobial resistance is growing in the general world population, estimated to have caused the death of 700,000 people annually throughout the globe, and forecast to kill ten million yearly by 2050 should the situation of antibiotic resistance not be controlled. Multiple animal species are thought to carry the gene, but scientists have become specifically concerned about domestic dogs being a carrier simply because of their proximity to humans.

Fecal samples were taken from 126 healthy people living with 102 cats and dogs from 80 households in a two year period up to February 2020. Of that number, eight dogs and four people were discovered to possess bacteria, including mer-1. Mer-1 gene was found in two households where dogs had tissue infections, having infected both dog and owner with analysis suggesting the gene was passed from dog to owner.

Sharing sleeping arrangements with dogs has been identified as another of the contagion opportunities where the mer-1 gene is transmitted; harboured in the gut, transported via microscopic fecal particles. Experts have warned for years that the overuse of colistin in particular on meat-producing animals, raises the risk of mutant genes with the potential to render the drug useless for humans.