Could the bacteria described in this research be another probiotic or beneficial bacteria (besides Lactobacillus sakei) that helps protect against sinusitis? New research found that the harmless bacteria Corynebacterium accolens is "overrepresented" in children free of Streptococcus pneumoniae (pneumococcus) - which commonly colonizes in children's noses (and that can live harmlessly as part of a healthy microbiome), but it is also an important infectious agent. Streptococcus pneumoniae is a major cause of pneumonia, septicemia, meningitis, otitis media (ear infections), and sinusitis in children and adults worldwide.
The researchers did an analysis on the microbes in the nasal passages of children and found that the nasopharyngeal (nostrils) microbiome was different in children with and without pneumococcal nasopharyngeal colonization. This revealed that Corynebacterium species and Dolosigranulum were "overrepresented" in children negative for pneumococcal colonization, whereas Streptococcus was "overrepresented" in children positive for Streptococcus pneumoniae colonization.
The researchers found that higher numbers of Corynebacterium accolens cells deter and limit S. pneumoniae nostril colonization, which might partly explain why children without S. pneumoniae colonization have higher levels of nasal Corynebacterium species. The researchers write that "there is direct antagonism" between Corynebacterium spp. and S. pneumoniae in the human nose. How do children get this beneficial bacteria? Interestingly, at 6 weeks of age, Corynebacterium species. and Dolosigranulum species are also "overrepresented" in the nasopharyngeal microbiota of breastfed infants compared to formula-fed infants. From Science Daily:
A new study is helping to shed more light on the important connections among the diverse bacteria in our microbiome. According to research published in mBio, scientists at Forsyth, led by Dr. Katherine P. Lemon, along with their collaborator at Vanderbilt University, have demonstrated that a harmless bacterium found in the nose and on skin may negatively impact the growth of a pathogen that commonly causes middle ear infections in children and pneumonia in children and older adults.
This study provides the first evidence that Corynebacterium accolens, a harmless bacterial species that commonly colonizes the nose, can help inhibit Streptococcus pneumoniae (S. pneumoniae) -- a major cause of pneumonia, meningitis, middle ear infection and sinusitis. According to the World Health Organization, S. pneumoniae leads to more than 1 million deaths each year, primarily in young children in developing countries. Although most people that host S. pneumoniae do not develop these infections, colonization greatly increases the risk of, and is a perquisite for, infection and transmission.
The study, titled, "Corynebacterium accolens (C. accolens) Releases Antipneumococcal Free Fatty Acids from Human Nostril and Skin Surface Triacylglycerols," is published on January 5, 2016 in mBio. In this study, first-author Dr. Lindsey Bomar and her colleagues show that C. accolens are overrepresented in the noses of children that are not colonized by S. pneumoniae, which is commonly found in children's noses and can cause infection. In laboratory research, the team further found that C. accolens modifies its local habitat in a manner that inhibits the growth of S. pneumoniae by releasing antibacterial free fatty acids from representative host skin surface triacylglycerols. The team went on to identify the C. accolens enzyme needed for this. These results pave the way for potential future research to determine whether C. accolens might have role as a beneficial bacterium that could be used to control pathogen colonization.