#Bacterial Factors Required for #Transmission of #Streptococcus pneumoniae in #Mammalian Hosts (Cell Host Microbe, abstract)

[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.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.