Lipari School on BioInformatics and Computational Biology
Jacob T. Schwartz International School for Scientific ResearchStefania Stefani, University of Catania, Italy
The probiotic approach in the microbiome and multi-drug-resistant era
Human microbiome studies, initially focussed on sequencing the metagenomes of the gut, mouth, skin, vagina, and nose of healthy volunteers, are now flourishing all around the world with the aim of studying its complexity for personalized medicine and medical screenings, including the assessments of one's microbial health.
Simply identifying the microorganisms and sequencing genes within these microbiomes will not provide the depth of understanding of microbial communities that is needed to design effective approaches for preventing and treating human diseases. Sequence information suggests hypotheses to test, and can inform the design of experiments needed to elucidate community behaviour. However, we will need to develop a deeper understanding of the physiology and ecology of microbial communities before we can manipulate these communities to achieve desired human health outcomes.
One of the major problem in public health is the extraordinary increase and spread of antibiotic resistance among many microrganisms in all clinical settings and in diverse environments. To deal with this enormous problem, different approaches other than the discovery of new drugs, are needed, in order to deal with infections sustained by MDR and XDR microorganisms. For instance, the probiotics development, i.e. the use of beneficial strains to restore an healthy status, appear to be an excellent way to prevent symptoms even after exposure to pathogens and, ultimately, to prevent infectious diseases.
To date, our group has isolated, characterized and patented a strain of S. salivarus, normal colonizer of the mouth and upper respiratory tract, the 24SMBc (DSM23307) strain, for its probiotic property, i.e. safety for the host, and remarkable inhibitory capacity versus S. pneumonia and S.pyogenes. The 24SMBc complete genome sequence (submitted), allowed us to identify a genomic strain-specific target identification, that allow us to monitor its presence in all biological samples analyzed. Thanks to these and many other characteristics, 24SMBc finds an excellent application in the prevention of recurrent acute otitis media rAOM and/or URTs also in pediatric age children. Immunamodulatory properties, as well as other information related to its interaction with the microbial communities of the respiratory tract, in both healthy and pathological conditions, are in study.
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