Link: MRSA vaccine shows promise in mouse study.
When they vaccinated the mice using the combined vaccine, however, all of the mice survived. Although unvaccinated mice had clear evidence of kidney infections, the "bacterial load" in vaccinated mice was reduced "to a level below detection."
The next step was to test the vaccine’s ability to protect mice from multiple bacterial strains isolated from humans. The researchers vaccinated 50 mice. Three weeks later, they injected groups of 10 with potentially lethal doses of one of five different clinical isolates.
The vaccine completely protected mice against two strains–including the virulent community-associated strain–and offered significant protection, resulting in 60- to 90-percent survival, against three other strains. All unprotected mice injected with the USA100 strain died within 36 hours, for example, but 60 percent of vaccinated mice survived injection with that strain.
"Further testing," said first author of the study Yukiko K. Stranger-Jones, a graduate student in the Schneewind Lab, "may yield a molecular appreciation of immunity against S. aureus and permit rational development of a vaccine." Schneewind and colleagues are now exploring the relationship between antibodies that fight S. aureus infection and surface proteins of the bacterium that facilitate the spread of the infection.
