An international team of scientists studying the transmission of a deadly drug-resistant bacterium, rivaling MRSA, has found that while this bacterium is present in livestock, pets and the environment in general, it is rarely transmitted to man this way.
The researchers, led by Professor Ed Feil from the Milner Center for Evolution at the University of Bath, studied the prevalence of the drug-resistant bacteria in cattle. Klebsiella, a family of bacterial species that live harmlessly in the intestines, but can be dangerous if spread to other parts of the body.
Klebsiella pneumoniae is the best known species of this family, which can cause pneumonia, meningitis, urinary tract infections and bloodstream infections.
These bacteria are now highly resistant to antibiotics, with some strains even resistant to carbapenems, a class of so-called “last resort” antibiotics, which is only used when no other antibiotic treatment works.
Klebsiella has overtaken MRSA as a health problem in the UK, with rates rising steadily. The WHO has recognized this bacterium as a critically important healthcare-associated pathogen.
Apart from being present in hospitals, the microbe has also been detected in the environment, including in livestock and sewage, but until now it was unclear whether the bacterium was transmitted between clinical and non-clinical settings.
In the largest study ever, the team collected 6,548 samples over a 15-month period from different locations in and around the Italian city of Pavia, where this pathogen is a major problem in hospitals, and analyzed them using whole genome sequencing techniques to detect and identify any transmission of the bacteria. Klebsiella bacteria present.
The team took samples from patients in hospitals and healthy “carriers” in the community, as well as samples from farms, puddles, pets and even house flies and other insects to detect the places where the bacteria was present.
They thus found 3,482 isolates, including 15 different species of bacteria. Klebsiellahalf of the positive samples containing K. pneumoniae.
When the team genetically sequenced the bacteria to determine the strains present, they found that there was very little overlap between the microbes found in hospitals and those found in the environment.
Professor Ed Feil, who led the study, said: ” Klebsiella Klebsiella infections are becoming increasingly resistant to antibiotics. While most UTIs might once be easily treated, it is now more common for patients to get infections that keep coming back and causing problems.
« Klebsiella can also cause pneumonia, which kills regarding half of patients. These bacteria are a bigger problem in the UK than MRSA.
“Our researchers wanted to know if the resistant bacteria were now spreading in pets, farms, livestock, plants and water. Klebsiella and monitor its spread, to determine how best to prevent and control outbreaks.
“We found that it was present everywhere, but we were surprised to find that the strains found in the hospital were different from those found in the environment, which indicates that there is very little transfer between two habitats: humans almost always catch it from other humans.
“This confirms that the best way to control infection for these bacteria is still rigorous hospital hygiene, and that outbreaks are less likely to be caused by contact with animals or the environment than the previously feared, at least in a high-resource country like Italy. »
The fear was that farmers might pick up these bacteria from their livestock or the soil, that we might get infected from contaminated salad or get sick if we bathe in infected lakes.
Our research has found no evidence of this, however, we have found resistant Klebsiella in companion animals, such as cats and dogs. Veterinarians and owners should be aware of this, as these animals might pose a risk of spreading the bacteria. »
Dr Harry Thorpe, first author of the article, University of Oslo (Norway)
The project consortium, called SpARK, was led by Bath but included researchers from the UK (Wellcome Sanger Institute, Universities of Bristol and Glasgow), Norway, France, Finland and Italy. The work was funded by the Joint Programming Initiative on Antimicrobial Resistance (JPI-AMR) and the MRC, and published in Nature Microbiology.
Professor Feil said: “This is the largest and most systematic study that has been carried out at one time in a single geographical location.
“We studied the transmission of strains, but resistance to antibiotics can be conferred on other strains very easily when they swap and take up circular pieces of DNA called plasmids.
“Next, we want to track how plasmids are transferred between strains, using a technique called long-read sequencing. »
The team recently received a network grant from the JPIAMR to do this, which relies on a GW4 research community and was supported by the AMR GW4 Alliance.
Source :
Journal reference:
Thorpe, H.A., et al. (2022) A large-scale genomic snapshot of Klebsiella spp. in northern Italy shows limited transmission between clinical and non-clinical settings.. Nature Microbiology. doi.org/10.1038/s41564-022-01263-0.
