A Journal of the American Medical Association,

and a Center for Disease Control report in 2007,
showed that MRSA is responsible for more than
18,500 hospital-stay related deaths each year,
and increased direct healthcare costs of as much
as $9.7 billion.

Extensive research was done in the 50′s around
using marijuana for treating tuberculosis. In those
experiments, marijuana research showed great
antibacterial activity against several bacteria
that commonly infect humans.

Then in 2008, this blockbuster marijuana research
was released:

J Nat Prod. 2008 Aug;71(8):1427-30. Epub 2008 Aug 6.

Antibacterial Cannabinoids from Cannabis Sativa: a structure-activity study.
Appendino G, Gibbons S, Giana A, Pagani A, Grassi G, Stavri M, Smith E, Rahman MM.
Dipartimento di Scienze Chimiche, Alimentari, Farmaceutiche e Farmacologiche, Università del Piemonte Orientale, 28100 Novara, Italy.
appendino@pharm.unipmn.itThis e-mail address is being protected from spambots. You need JavaScript enabled to view it

Marijuana (Cannabis sativa) has long been known to contain antibacterial cannabinoids, whose potential to address antibiotic resistance has not yet been investigated. All five major cannabinoids (cannabidiol (1b), cannabichromene (2), cannabigerol (3b), Delta (9)-tetrahydrocannabinol (4b), and cannabinol (5)) showed potent activity against a variety of methicillin-resistant Staphylococcus aureus (MRSA) strains of current clinical relevance. Activity was remarkably tolerant to the nature of the prenyl moiety, to its relative position compared to the n-pentyl moiety (abnormal cannabinoids), and to carboxylation of the resorcinyl moiety (pre-cannabinoids). Conversely, methylation and acetylation of the phenolic hydroxyls, esterification of the carboxylic group of pre-cannabinoids, and introduction of a second prenyl moiety were all detrimental for antibacterial activity. Taken together, these observations suggest that the prenyl moiety of cannabinoids serves mainly as a modulator of lipid affinity for the olivetol core, a per se poorly active antibacterial pharmacophore, while their high potency definitely suggests a specific, but yet elusive, mechanism of activity.

In simple English, this abstract can be translated
as “Marijuana has been shown to be powerfully effective
against many types of bacteria, but how it works remains
a mystery.”