For the first time, cannabidiol (CBD), has been shown to kill several strains of bacteria that can cause gonorrhea, meningitis, and legionnaires disease.
The research conducted in collaboration between the University of Queensland and Botanix Pharmaceuticals Limited complements several other reports in recent years demonstrating the antibiotic potential of CBD. The research team believes CBD may provide the foundation for the development of a new class of antibiotics.
The study found CBD effective against a diverse range of over 20 different types of bacteria including several drug-resistant strains, and the sometimes difficult-to-treat family of Gram-negative bacteria.
Gram-negative bacteria are more likely to become resistant to antibiotics due to the presence of an extra outer membrane. This acts as “an additional line of defense” by blocking drugs from penetrating into the cell.
The bacteria that cause gonorrhea, meningitis, and legionnaires disease all fall within this category.
“This is the first-time CBD has been shown to kill some types of Gram-negative bacteria,” said study co-author Mark Blaskovich.
“This [finding] is particularly exciting because there have been no new molecular classes of antibiotics for Gram-negative infections discovered and approved since the 1960s,” Blaskovich added. “And we can now consider designing new analogs of CBD with improved properties.”
Blaskovich explained that CBD was also particularly useful in breaking down biofilms – the slimy buildup of bacteria and other microorganisms. Common biofilms include dental plaque and pond scum.
The thick consistency of biofilms can make it difficult for antibiotics to fully penetrate, which helps bacteria better survive antibiotic treatments.
CBD also effective against certain drug-resistant “superbugs”
Part of Blaskovich’s study also focused on testing whether CBD could kill a variety of multiple drug-resistant strains of bacteria commonly referred to as “superbugs.”
According to the U.S. Centers for Disease Control and Prevention (CDC), widespread overuse of antibiotics has led to a number of disease-causing bacteria developing resistance to conventional antibiotics.
In the U.S., “superbugs” infect more than 2.8 million people and kill at least 35,000 every year.
As part of the study, CBD was tested against several strains of drug-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, and Neisseria gonorrhoeae. These bacteria can cause staph infections, respiratory illnesses, and gonorrhea, respectively.
These drug-resistant strains account for an estimated 14,200 deaths in the U.S. yearly and are flagged by the CDC as “serious threats.”
In the study, CBD killed off multiple Australian and American clinical strains of these drug-resistant bacteria, in many cases working just as effectively as it did on non-drug resistant strains.
In fact, CBD worked at a similar concentration as vancomycin, the current first-line therapy for severe drug-resistant MRSA staph infections. Even more surprisingly, CBD was also able to kill vancomycin-resistant MRSA as well.
To further their study, the research team also created a model to test whether bacteria could mutate and become resistant to CBD’s antibiotic properties over time.
“Cannabidiol showed a low tendency to cause resistance in bacteria even when we sped up potential development by increasing concentrations of the antibiotic during treatment,” Blaskovich said.
In the test, MRSA bacteria were more likely to become resistant to the traditional antibiotic, daptomycin, than CBD over a 20-day period.
Part of that may be due to how CBD can break down the bacteria’s protective membranes, causing them to tear open.
“We think cannabidiol kills bacteria by bursting their outer cell membranes, but we don’t know yet exactly how it does that and need to do further research,” Blaskovich explained.
CBD clinical trials for drug-resistant bacteria in progress
Collaborative efforts between the University of Queensland and Botanix Pharmaceuticals are now focused on clinical trials for a topical CBD formula that can be used to treat MRSA.
Early results from their clinical trial found that CBD could eradicate up to 76.2% of MRSA from affected areas after just 7 days of treatment.
MRSA is one of the leading causes of post-operation surgical site infections but growing resistance towards conventional antibiotics has made certain strains difficult to treat.
“We hope that this will pave the way for treatments for gonorrhea, meningitis, and legionnaires disease,” Blaskovich said.
“We are looking at [cannabidiol’s] mode of action, improving its activity, and finding other similar molecules to open up the way for a new class of antibiotics.”