Fecal particles from one person reaching the mouth of another are to blame for most infections by antibiotic resistant bacteria. Highlighting the rule that it is very important to wash your hands after using the toilet.
E. coli can be found within the lower intestine of warm blooded organisms, normally the bacterium aids in digestion but it can cause problems if it infects another area of the body. Although frequently associated with transference from under-cooked meat and poorly washed produce, this study from East Anglia University has found that rather than anything related to food or eating E. coli is much more likely to be spread from person to person via poor hygiene habits.
E.coli has several different strains which can cause anything from severe food poisoning to urinary tract infections; in the worst cases exposure can lead to bacteraemias or bloodstream infections. Many strains have developed a resistance to conventional antibiotics as the harbor Extended Spectrum Beta-Lactamases enzymes that can destroy most antibiotics.
Until now it has always been uncertain whether strains are most spread through food/eating or via person to person transference. To investigate resistance E. coli genomes were sequenced from various sources across the UK including human sewage, human feces, human bloodstream, infection, animal manure, and various foods.
Analysis revealed that all of the superbug strains of E. coli stemming from sources like human blood, feces, and sewer samples were very similar to another, specifically among the ESBL strains where ST131 dominated findings regarding human samples; strains from food as well as animal waste were different from the strains most commonly infecting humans.
“E. coli bacteria normally live in the intestines of healthy people and animals. Most varieties are harmless or cause brief diarrhea,” explains lead author professor David Livermore in a release. “But E. coli is also the most common cause of blood poisoning, with over 40,000 cases each year in England alone. And around 10 percent of these cases are caused by highly resistant strains with ESBLs. Infections caused by ESBL-E. coli bacteria are difficult to treat. And they are becoming more common in both the community and hospitals. Mortality rates among people infected with these superbug strains are double those of people infected with strains that are susceptible to treatment.”
“We wanted to find out how these superbugs are spread – and whether there is a crossover from the food chain to humans,” professor Livermore continues. “We looked at more than 20,000 fecal samples and around nine per cent were positive for ESBL-E. coli across the regions, except for in London, where the carriage rate was almost double – at 17 per cent,” Professor Livermore says. “We found ESBL-E. coli in 65 percent of retail chicken samples – ranging from just over 40 per cent in Scotland to over 80 per cent in Northwest England. But the strains of resistant E. coli, were almost entirely different from the types found in human feces, sewage and bloodstream infections.”
Only a few pork samples tested positive, and the bacteria wasn’t detected at all among over 400 fruit and vegetable samples that were tested. Findings indicate there is a clear distinction between human based strains and animal strains, meaning there is actually little crossover between human and animal strains and most human infections are not coming from food sources.
“Rather – and unpalatably – the likeliest route of transmission for ESBL-E. coli is directly from human to human, with fecal particles from one person reaching the mouth of another,” Professor Livermore concludes. “We need to carry on cooking chicken well and never to alternately handle raw meat and salad. There are plenty of important food-poisoning bacteria, including other strains of E. coli, that do go down the food chain. But here – in the case of ESBL-E. coli – it’s much more important to wash your hands after going to the toilet.”
