Antimicrobial resistance bacteria found in raw pet food

The fight against antimicrobial resistance has a new problem – raw pet food, according to new research. Sales of biologically appropriate raw food, especially for dogs, have risen in recent years.

Microbiologists working in Switzerland have assessed 51 samples of raw diet pet food, drawn from different suppliers in stores as well as from the Internet. The analysis revealed that some three-quarters of the food samples contained bacteria that has the potential to trigger gastrointestinal infections limits.

Furthermore, over half of the foods that tested were found to contai bacteria that are resistant to antimicrobials, meaning that such organisms are hard to kill. Among the bacteria were certain strains of Escherichia coli. Some bacteria can produce the enzyme extended-spectrum beta-lactamase (EBSL), which can enable these microorganisms to resist the impacts of antibiotics.

Other pathogens that have been isolated from raw pet food includes Campylobacter spp, Clostridium spp, enterotoxigenic Staphylococcus aureus, Listeria monocytogenes, and Salmonella spp.

According to lead researcher Dr. Magdalena Nuesch-Inderbinen: “It is really worrying that we found EBSL-producing bacteria in over 60 percent of samples.”

The new research highlights a new area of concern in the battle against antimicrobial resistance. Antimicrobial resistance is a phenomenon the occurs naturally as bacteria respond to various pressures within the environment. What is of concern is the worldwide acceleration of resistance. U.S. Centers for Disease Control and Prevention (CDC) data finds that many high-income countries are entering a “post antibiotic era.”

One reason for the trend is linked to the practice of animal feed-additive antibiotic usage, which is some countries is an integral part of animal-production technology. The reason for adding of antibiotics is for the creation of 'leaner' meat (animals given antimicrobial tend to grow more quickly). In addition, the indiscriminate administering of antibmicrobials to animals is a way of side-stepping putting in place better animal hygiene conditions.  Many countries have banned this practice, but it also continues in many other parts of the world.

The study additionally highlights concerns for pet owners when considering to buy raw food and then how that food is handled in the home.  In fact, the American Veterinary Animal association “discourages the feeding to cats and dogs of any animal-source protein that has not first been subjected to a process to eliminate pathogens because of the risk of illness to cats and dogs as well as humans.”

The research findings have been reported in the journal Royal Society Open Science.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology