For the first time ever, researchers at the University of Queensland have found how cannabis can provide a solution to antibiotic-resistant bacteria. A non-psychoactive cannabinoid known as cannabidiol (CBD) has been found to penetrate and kill several highly resistant bacteria, including those responsible for gonorrhea, MRSA, and meningitis. The findings could lead to the creation of the first class of antibiotics for resistant bacteria in 60 years.
There is an urgent need to develop new antibiotics to treat diseases like gonorrhea, which infects close to 100 million people worldwide annually, with the process being extremely challenging due to the frequency of asymptomatic infections along with gonorrhea’s ability to adapt to its host’s immune system and develop resistance to antibiotics.
Bacteria can be classified into two broad categories of gram-negative and gram-positive bacteria. While previous research has proven CBD’s efficiency when it comes to tackling the latter, there has been an assumption so far that the compound wouldn’t work against the former, due to their unique formation, that also renders many antibiotics futile in destroying them. However, the study published in the journal Communications Biology has shown otherwise.
“This is the first time CBD has been shown to kill some types of Gram-negative bacteria. These bacteria have an extra outer membrane, an additional line of defence that makes it harder for antibiotics to penetrate,” said lead author Mark Blaskovich, who’s also an assistant professor at the UQ Institute for Molecular Bioscience in Australia.
The range of gram-negative bacteria that CBD was found to be able to destroy included Neisseria gonorrhoeae, which causes gonorrhea, popularly known as “the clap”. Gonorrhea can infect the genitals, rectum, and throat. Symptoms include discharge from the urethra or vagina and burning during urination called urethritis, caused by inflammation of the urethra. However, many who are infected don’t experience any symptoms, meaning they go undiagnosed and untreated. The sexually transmitted disease has been a tough one for science to crack for decades due to the bacteria’s frightening ability to acquire resistance from other bacteria quickly, which it finds especially easy to do when it cohabits the throat with other bacteria after oral sex.
If left untreated or not properly treated, gonorrhea can lead to serious complications that disproportionately affect women, who are more likely to be asymptomatic. Untreated gonorrhea not only increases the risk of contracting HIV but is also linked with an increased risk of pelvic inflammatory disease, which can cause ectopic pregnancy and even infertility. A pregnant woman can also pass on the infection to the foetus, who then stands the risk of being born blind.
As part of the research, scientists applied CBD, as well as other slightly altered CBD analogs, to samples of pig skin that had been infected by different kinds of bacteria. While topical applications of CBD showed great results, the compound was found largely ineffective when injected into mice infected with various bacteria. This could be due to CBD’s tendency to bind to compounds present in blood plasma, leading to its unavailability at the systemic level to fight infections.
Fortunately, the CBD analogs with slight tweaks also proved to be equally potent at destroying bacteria, giving rise to hopes that it could be possible to create a slightly altered version of the compound with high systemic availability.
“This is particularly exciting because there have been no new molecular classes of antibiotics for gram-negative infections discovered and approved since the 1960s, and we can now consider designing new analogs of CBD within improved properties,” Blaskovich said.
The researchers also went a step further to study how fast the bacteria could mutate to try and outwit CBD and its killing power. In a mock two-week patient treatment trial, it was found that CBD causes a low tendency to show resistance in bacteria, even when antibiotic concentrations were increased in order to speed up the process.
The study was conducted in collaboration with Botanix Pharmaceuticals, who have now been able to progress a topical CBD formulation into clinical trials for decolonisation of MRSA before surgery.
These findings come at the right time, with the number of people infected by gonorrhea continuing to grow by 17 percent every year due to the bacteria’s highly resistant nature, according to World Health Organization (WHO) estimates. Only in December 2020, WHO media had sounded the alarm about a strain of super gonorrhea, fuelled by overuse and certain antibiotics and lack of medical attention towards sexually transmitted diseases during the pandemic.
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