One of the deadliest living things on Earth is a tiny cell. A leading killer of children worldwide, the pneumococcus bacterium is responsible for pneumonia, meningitis, otitis media ear infections and other illnesses.
St. Jude researchers have discovered how an enzyme helps pneumococcus survive and become invasive in the body. The findings have profound implications for current treatment and vaccine strategies.
The enzyme, LytA, helps pneumococcus quickly shed its outer layer, or capsule, soon after infecting a host. With no capsule, the bacterium can more readily escape the immune system’s frontlines, enter host cells and spread into the bloodstream.
“The majority of antibacterial vaccines currently target the capsule to trigger the protective immune response,” said Elaine Tuomanen, MD, of St. Jude Infectious Diseases. Therefore, the results may explain why current vaccines are less effective in diseases where pneumococcus has less capsule, such as pneumonia and ear infections.
While preventing infection is a key goal, researchers also seek ways to block pneumococcus’ spread after infection. “The pathway is new to microbiology and may provide clues for designing drugs to prevent invasive disease,” noted Tuomanen.
The findings were published in Nature Communications.