Deadly superbugs are spread miles from farms by house flies



House flies found miles from farms were carrying antibiotic resistant bacteria

Potentially deadly superbugs can be spread by flies from farms to people living miles away, scientists warned last night.



Researchers have found disturbing evidence that houseflies and cockroaches carry antibiotic-resistant strains of bacteria normally found in the guts of livestock.



In tests, the same strains living in the intestines of pigs were discovered in insects flying and crawling around the farm. Flies can travel for miles, spreading bacteria each time they land on food.



Organic farmers said the study highlighted the dangers of overusing antibiotics on farms and called for an urgent inquiry into the links between livestock and superbugs.



Although drug resistant bacteria such as MRSA are usually regarded as problems for hospitals, there is increasing evidence linking superbugs to farms.



Until the mid 2000s, farmers traditionally used antibiotics to speed up weight gain in pigs, chickens and other livestock. After they were banned as growth promoters by the EU, their use has fallen slightly in the UK.



However, campaign groups says farmers are still too dependent on antibiotics for minor ailments and that overuse increases the risk of bacteria evolving resistance to drugs needed to cure disease in people.



The new study, published in the journal BioMed Central Microbiology, compared bacteria in farmyard pigs with bacteria in house flies and cockroaches found on the same American farms.

Not only were the same types of bacteria discovered in insects and pigs, there was also a high rate of antibiotic resistance.

Two common types of Enterococcus gut bacteria were frequently resistant to four common antibiotics used to treat people.



Dr Ludek Zurek said the findings could be "very important" for human health.



'The digestive tract bacteria in pigs are often exposed to selective pressure and many become resistant to antibiotics,' he said.



'Consequently, there's a risk that these bacteria might be transferred – by common livestock and urban pests such as house flies and cockroaches from pig farms to humans'.

The insects were spreading the potentially deadly bacteria found in the intestines of pigs

Past studies by Dr Zurek have shown flies in fast food chains carrying antibiotic resistant bacteria.



'House flies are attracted to human food and drinks, they are pretty mobile - they can fly several kilometres - and are very good in contaminating food and other surfaces due to that fact that house flies cannot feed on a solid food,' he added.



'They have to regurgitate saliva and content of the gut to liquefy the solid food – this way they spit out lots of bacteria.'



However, there was no evidence that flies have already passed on drug resistant strains of bacteria, he added.



Last year, the Soil Association warned of shocking levels of E.coli and salmonella superbugs on British farms. Another, almost untreatable, type of antibiotic resistance in E coli, known as extended-spectrum beta-lactamase (ESBL) resistance has spread from a handful of farms to more than one in three dairy farms in England and Wales.



Richard Young from the Soil Association said: 'There is solid evidence that the overuse of antibiotics in pig farming is causing and amplifying the problem of MRSA in pigs. There needs to be an urgent review of the overuse of antibiotics before pig MRSA becomes established in British pigs.



'The Soil Association is calling for more sensitive testing of UK pigs - this has already happened in other EU countries - restrictions of live imports and more testing for any imports that are coming in.



'MRSA has yet to be found in British pigs, but if it is introduced it would spread rapidly, as it has done in other countries in Europe with high-use of antibiotics such as the Netherlands, Germany and Spain.



'This has serious implications for both animals and humans. Excessive antibiotic use in farm animals leads to higher levels of antibiotic resistance, which can have consequences for animal health and welfare, as diseases become untreatable, and for human health, when resistant bacteria transfer from animals to humans.'

