Nav: Home

Vaccination with Streptococcus mitis could protect against virulent sibling, Streptococcus pneumonia

January 30, 2019

Vaccinating laboratory mice with Streptococcus mitis bacteria prevents their virulent sibling, Streptococcus pneumoniae from infecting the mice. The research suggests that vaccination of humans with live S. mitis might offer protection from some of the many serotypes of S. pneumoniae that vaccines currently do not exist for. This pathogen is one of the most common causes of severe pneumonia, and can also cause meningitis, bloodstream and sinus infections, endocarditis, and middle ear infections in young children. The research is published in Applied and Environmental Microbiology.

S. pneumoniae afflicts about 14 million children, annually, killing 2-3 million, including around a million under age five. Resistance to antibiotics is an increasing problem, underscoring the need for vaccines, according to the report. And current vaccines target only 13 of more than 90 serotypes of S. pneumoniae.

S. mitis, which lacks many of the virulence genes present in S. pneumoniae, but is otherwise quite similar, commonly inhabits the oral cavity and the upper respiratory tract, living in peaceful coexistence with the host.

The investigators intranasally vaccinated mice with two different versions of S. mitis, to compare their efficacy: wild type S. mitis, and S. mitis which they had genetically engineered to express a sugar coat that is found on the exterior of the cell wall of S. pneumoniae. Serotype 4, they posited, might strengthen the antibody response to S. penumoniae.

Vaccination with the S. mitis vaccine boosted production of IgG and IgA antibodies, as well as Th17 cells (the investigators did not examine production of such antibodies and cells following vaccination with the engineered vaccine), said principal investigator Fernanda C. Petersen, DDS, PhD, Professor of molecular microbiology, University of Oslo, Norway.

IgG is an important antibody in the blood and other bodily fluids, and IgA is critical in secretions, especially those of the mucus epithelium of the intestinal and respiratory tracts. Th17 cells are pro-inflammatory cells that play an important role in fighting invading pathogens.

The engineered vaccine worked as expected, boosting protection against S. pneumoniae serotype 4, but not against S. pneumoniae serotype 2, as compared to the wild type vaccine.

Co-corresponding author Sudhanshu Shekhar, PhD, a postdoctoral researcher in Dr. Petersen's group, noted that one must be cautious in extrapolating results from mouse models to humans, and emphasized that protection of humans would remain hypothetical until human studies have been performed.

The report also noted that commensal live vaccines circumvent the main limitation of vaccinations with attenuated live pathogens: reversion to virulence.

"Bacterial live vaccines can be highly efficient because they mimic the natural infection," said Dr. Petersen. "They have been known for decades to prevent respiratory and enteric infections in humans. The main challenge, however, is to engineer attenuated versions that are safe as vaccines, but still offering protection. Our study reveals that S. mitis a natural human colonizer that resembles S. pneumoniae but seldom causes diseases, can be the answer offered by nature for a safe vaccine against S. pneumoniae."
-end-
The American Society for Microbiology is the largest single life science society, composed of more than 32,000 scientists and health professionals. ASM's mission is to promote and advance the microbial sciences.

ASM advances the microbial sciences through conferences, publications, certifications and educational opportunities. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.

American Society for Microbiology

Related Vaccination Articles:

Researchers develop microneedle patch for flu vaccination
A National Institutes of Health-funded study led by a team at the Georgia Institute of Technology and Emory University has shown that an influenza vaccine can produce robust immune responses and be administered safely with an experimental patch of dissolving microneedles.
Rotavirus vaccination in infants and young children
Rotaviruses (RV) are the commonest cause of diarrhea in infants and young children worldwide.
Industry and occupation affect flu vaccination coverage
Not surprisingly, healthcare workers are almost twice as likely to get flu vaccines as those in other occupations.
Child's vaccination data handily available via Kasvuseula service
Parents can now follow their tots' vaccinations via the Kasvuseula online service, which provides analytical data on the child's growth.
Foot-and-mouth crises to be averted with vaccination strategy
Future outbreaks of foot-and-mouth disease (FMD) can be controlled effectively and quickly with vaccinations -- saving millions of pounds and hundreds of thousands of livestock -- according to research by the University of Warwick.
HPV prevalence rates among US men, vaccination coverage
Human papillomavirus (HPV) infection is the most common sexually transmitted infection in the United States, as well as a cause of various cancers, and a new study published online by JAMA Oncology estimates the overall prevalence of genital HPV infection in men ages 18 to 59.
Anesthetic cream best for relieving vaccination pain in infants
For babies under age one year, lidocaine cream, combined with a small amount of sugar given by mouth and infant soothing, can help relieve pain from routine vaccinations, according to a study in Canadian Medical Association Journal.
Measles prevention -- how to pull the trigger for vaccination campaigns?
Routine vaccination has greatly reduced measles deaths in recent years, but very high vaccination coverage is needed to prevent disease outbreaks.
Using satellite images to better target vaccination
Vaccination campaigns can improve prevention and control of disease of outbreaks in the developing world by using satellite images to capture short-term changes in population size.
Maternal vaccination again influenza associated with protection for infants
How long does the protection from a mother's immunization against influenza during pregnancy last for infants after they are born?

Related Vaccination Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".