[Source: Cell, Host & Microbe, full page: (LINK). Abstract, edited.]
Bacterial Factors Required for Transmission of Streptococcus pneumoniae in Mammalian Hosts
Hannah M. Rowe, Erik Karlsson, Haley Echlin, Ti-Cheng Chang, Lei Wang, Tim van Opijnen, Stanley B. Pounds, Stacey Schultz-Cherry, Jason W. Rosch
Published: May 21, 2019 / DOI: https://doi.org/10.1016/j.chom.2019.04.012
- A pneumococcal Tn-seq library was screened in a ferret transmission model
- The fitness landscape of S. pneumoniae genes during mammalian transmission established
- Metabolic factors enhance pneumococcal environmental stability
- Vaccinating dams with identified factors blocks pneumococcal transmission in offspring
The capacity of Streptococcus pneumoniae to successfully transmit and colonize new human hosts is a critical aspect of pneumococcal population biology and a prerequisite for invasive disease. However, the bacterial mechanisms underlying this process remain largely unknown. To identify bacterial factors required for transmission, we conducted a high-throughput genetic screen with a transposon sequencing (Tn-seq) library of a pneumococcal strain in a ferret transmission model. Key players in both metabolism and transcriptional regulation were identified as required for efficient bacterial transmission. Targeted deletion of the putative C3-degrading protease CppA, iron transporter PiaA, or competence regulatory histidine kinase ComD significantly decreased transmissibility in a mouse model, further validating the screen. Maternal vaccination with recombinant surface-exposed PiaA and CppA alone or in combination blocked transmission in offspring and were more effective than capsule-based vaccines. These data underscore the possibility of targeting pneumococcal transmission as a means of eliminating invasive disease in the population.
Keywords: Streptococcus pneumoniae – transmission – ferret – influenza
Keywords: Streptococcus pneumoniae; IPD; Animal models.