Study finds high level of drug-resistant E coli in UK chicken meat
New research from Public Health England and the Department for Environment, Food and Rural Affairs (DEFRA) has found that two thirds of raw chicken bought at UK supermarkets in 2013-2014 tested positive for extended-spectrum beta-lactamase (ESBL)–producing Escherichia coli.
In a study published Oct 29 in the International Journal of Food Microbiology, researchers tested 397 raw meat samples purchased from local retailers in five UK regions (London, East Anglia, North West England, Scotland, and Wales), along with 400 fruit and vegetable samples. Eighty percent of the meat came from UK food producers. ESBL-producing E coli was identified in 1.9% and 2.5% of beef and pork samples, compared with 65.4% of chicken samples. None of the fruits or vegetables tested positive.
The authors of the study say the data indicate that raw chicken is the most significant raw food source of ESBL-producing E coli to which the UK population is exposed, a notable finding given that ESBL-producing E coli is highly resistant to cephalosporin antibiotics. Yet they also found that none of the food samples yielded E coli with CTX-M-15 ESBL—the type of E coli that sickens people in Britain and elsewhere. In addition, they found that none of the samples tested positive for carbapanem-resistant E coli.
The authors also point out that cooking raw meat thoroughly will destroy any bacteria, whether it's drug-resistant or not.
Coilin Nunan of the Alliance to Save Our Antibiotics told the Daily Mail that the high rate of ESBL-producing E coli is a result of overuse of antibiotics in the British poultry industry. "For years the poultry industry was systematically injecting day-old chicks in breeding flocks with modern cephalosporins, despite these drugs being classified as critically important antibiotics in human medicine," Nunan said.
A recent report from the British government's Veterinary Medicines Directorate showed that the sales of antibiotics for use in food-producing animals dropped by 10% from 2014 to 2015.
Oct 29 Int J Food Microb abstract
Nov 21 Daily Mail story
Nov 17 Veterinary Medicines Directorate report
Predatory bacteria show potential as 'living antibiotic'
Scientists in England are reporting some promising findings in a study that examined whether a predatory bacterium can be effective against drug-resistant infections.
In the study, published today in Current Biology, researchers from Imperial College London and the University of Nottingham injected zebrafish larvae with Bdellovibrio bacteriovorus, a predatory bacterium that invades and kills a wide range of gram-negative bacterial pathogens in natural environments and in vitro. They wanted to see if Bdellovibrio had a pathogenic effect on the larvae, and whether the bacteria could survive long enough to prey on a predatory infection.
They found that the bacteria had no negative effect on the larvae, and that they could survive for long periods but need prey bacteria to replicate and act therapeutically before being naturally cleared by the immune system.
Once the researchers had determined that the Bdellovibrio had no toxic effect, the researchers injected zebrafish larvae with a lethal dose of drug-resistant Shigella flexneri, a bacterium that causes severe and sometimes deadly diarrhea (worldwide, Shigella infections cause more than 160 million illnesses and 1 million deaths). They then injected Bdellovibrio into the infection site to determine its efficacy against the pathogen. The larvae injected with the Bdellovibrio were able to control the replication of Shigella much better than those that didn't receive the bacterium, and survival increased by 35%.
What the researchers could see inside the translucent zebrafish larvae was Bdellovibrio working in conjunction with white blood cells known as leukocytes, which are the cells of the immune system that spring into action when the body is invaded by a pathogen. When they tried injecting the bacteria into Shigella-infected zebrafish with depleted leukocytes, they found that the impact wasn't as significant.
"This study really shows what a unique and interesting bacterium Bdellovibrio is as it presents this amazing natural synergy with the immune system and persists just long enough to kill prey bacteria before being naturally cleared," study co-author Serge Mostowy, PhD, said in a news release from the Wellcome Trust, which partially funded the study. "It's an important milestone in research into the use of a living antibiotic that could be used in animals and humans."
Mostowy and his colleagues say their findings warrant further research into the development of Bdellovibrio as a potential weapon against drug-resistant bacteria.
Nov 23 Curr Biol study
Nov 23 Wellcome Trust news release
Low-path H7 viruses shown to infect mammals without earlier adaptation
Low-pathogenic H7 avian influenza viruses circulating in wild birds in the United States and Canada can cause severe and often fatal disease in mammals, a team based at St. Jude's Children's Research Hospital in Memphis, Tenn., reported Nov 16 in the Journal of Virology.
The investigators looked at 30 low-pathogenic H7 viruses, testing each in mice. Twenty-seven (90%) had the capacity to kill the animals, and of those, 17 caused 100% mortality.
The researchers found that 24 of the H7 viruses had a similar pathogenicity profile to the H7N9 avian influenza responsible for waves of human illnesses in China, a strain that is highly pathogenic in mice.
They observed that H7 viruses isolated from ducks were more likely to kill 100% of the mice tested when compared to H7 viruses that had been isolated from shorebirds.
In exploring the scope of infection in the mice, the team found that evidence of replication in the heart and brain, and of 16 viruses tested for fecal shedding, 11 were found in those samples. Though the viruses showed a strong preference for avian-type airway receptors, they also were able to bind to mammalian ones.
Given that the H7 viruses are able to infect and cause disease in mammals without genetic changes, the threat to human health might be greater than previously thought, the authors concluded.
Nov 16 J Virol abstract
