Washington, Aug 19 (Inditop.com) A specific protein found on the surface of a common bacterial pathogen allows it to subvert the brain, triggering deadly meningitis in infants, scientists have found, possibly opening the way to better vaccines.
“Streptococcus pneumoniae, commonly known as pneumococcus, is responsible for half the cases of bacterial meningitis in humans,” said senior study author Victor Nizet, professor of paediatrics at the University of California, San Diego’s School of Medicine (UCSD-SM).
“As many as 30 percent of patients can die from this rapidly progressing infection, while half of survivors may be left with permanent neurological problems including deafness, seizures, intellectual deficits or motor disabilities,” said Nizet.
Meningitis develops when bacteria penetrate the “blood-brain barrier” (BBB). Comprising a single layer of highly specialised micro-vascular cells, BBB prevents most large molecules from breaching the cerebrospinal fluid in the brain.
The UCSD-SM team investigated the functions of a protein known as NanA in order to discover how an entire bacterium can breech the BBB and gain access to the central nervous system.
NanA is produced by all strains of pneumococcus and displayed prominently on the bacteria’s outer surface. Through genetic manipulations, the researchers removed the entire NanA protein, or just specific sections of the molecule, from the pathogen, said an UCSD-SM release.
“Our tissue culture studies showed that the NanA protein was both necessary and sufficient for bacterial penetration of the blood brain barrier…,” said Satoshi Uchiyama, a postdoctoral fellow in the Nizet Lab, who led the study.
These findings were published online in the Journal of Experimental Medicine.
