Researchers from University of Connecticut revealed that aeromonas bacteria found in leech is responsible for antibacterial resistance.
Antibiotic susceptibility is a major side effect of plastic surgery, were patients suffer from infections with antibiotic resistant bacteria. The research led by Joerg Graf, a microbiologist from the Department of Molecular and Cell Biology examined the contents of several leech guts them over the years. Leeches have two major types of bacteria inside their guts that makes them a perfect candidate for research. The first case of plastic surgery patients’ infection with Aeromonas bacteria—resistant to ciprofloxacin emerged in 2011. It was observed that the patients were treated with leeches to improve blood flow at surgical sites. Aeromonas bacteria are capable of surviving on blood, which leads to infections when these bacteria enter into wounds. Such infection is easily treated with ciprofloxacin and there would be no source of Cipro-resistant Aeromonas in a hospital. However, it was unclear as to how the bacteria develop resistance to ciprofloxacin.
The researchers analyzed the gut contents of leeches obtained from poultry farm blood and found traces of both ciprofloxacin and enrofloxacin in the bacteria. However, the amount of antibiotic present was around 0.01 micrograms per milliliter that was very less. The concentration was around four hundred times less than required, for the bacteria to be considered resistant to drug. The researchers sequenced the genome of isolated strains of Aeromonas from leeches contaminated with antibiotics. It was observes that the genome contained the three bits of DNA, two genes with mutations and a plasmid, which together are necessary for resistance to ciprofloxacin. Mutational genes are essential for DNA replication are important for survival in a host. Furthermore, it was observed that the test strains of Aeromonas grew all over the Cipro-resistant Aeromonas. However, when an antibiotic of around 0.01 micrograms/mL, was added into the mix the Cipro-resistant variety dominated. The use of antibiotics is banned in poultry farms in the US. However, low levels of unregulated antibiotics are present in hospital, pharma and sewage wastewater that risk developing resistance to the drugs. The research was published in the journal mBio on July 24, 2018.