Publication: Streptococcus pneumoniae Colonization Disrupts the Microbial Community within the Upper Respiratory Tract of Aging Mice

Colonization of Streptococcus pneumoniae within the upper respiratory tract (URT) of elderly individuals is a major concern, as it often results in the development of pneumonia, which can be deadly in this population. A study published by MIRC Masters’ student Netusha Thevaranjan, under the supervision of Dr. Dawn Bowdish, examined howNetusha-sm aging can change the composition of the respiratory microbial community and consequently, impact bacterial colonization. Using a mouse model of pneumococcal colonization, the study characterized the composition of the URT microbiota in young, middle-aged, and old mice in both the naïve state, and throughout the course of nasopharyngeal colonization with S. pneumoniae. It was shown that the composition of the URT microbiota differs with age, and that colonization with S. pneumoniae in older mice disrupted pre-existing microbial communities.

Furthermore, the study demonstrated that there were several interspecies interactions between S. pneumoniae and resident microbes. In particular,Streptococcus interacted competitively with Staphylococcus and synergistically with Haemophilus. This work provides insight into how aging influences bacterial colonization, and understanding the relationship between these two factors can help create strategies to protect the elderly from age-associated infections and disease. Read More

Whelan et al. The Loss of Topography in the Microbial Communities of the Upper Respiratory Tract in the Elderly. Ann Am Thorac Soc. 2014 Mar 6.

Whelan FJ, Verschoor CP, Stearns JC, Rossi L, Luinstra K, Loeb M, Smieja M, Johnstone J, Surette MG, Bowdish DM. The Loss of Topography in the Microbial Communities of the Upper Respiratory Tract in the Elderly. Ann Am Thorac Soc. 2014 Mar 6.

This paper describes how the microbial communities of the anterior nares and nasopharynx change between adults and the elderly. 

Grant Bonanza!

The Bowdish lab has received funding from the CIHR (Pilot Projects in Aging) with Dr. Jennie Johnstone to study how macrophage immunosenescence contributes to susceptibility to pneumonia in the elderly. We have also received funding from the Ontario Thoracic Society/Ontario Lung Association for our work on the role of scavenger receptors in mycobacterial infection and funding from the CIHR (Emerging Team: Human Microbiome, with Drs Mike Surette, Jennie Johnstone, Mike Schryvers, & James Kellner) to study the role of commensal bacteria (including close cousins of S. pneumoniae) contribute to upper respiratory tract infections. This is truly an exciting time for the Bowdish lab – stay tuned for some fantastic science!