title: Host-to-Host Transmission of Streptococcus pneumoniae Is Driven by Its Inflammatory Toxin, Pneumolysin.
abstract: Host-to-host transmission is a critical step for infection. Here we studied transmission of the opportunistic pathogen Streptococcus pneumoniae in an infant mouse model. Transmission from nasally colonized pups required high levels of bacterial shedding in nasal secretions and was temporally correlated with, and dependent upon, the acute inflammatory response. Pneumolysin, a pore-forming cytotoxin and major virulence determinant, was both necessary and sufficient to promote inflammation, which increased shedding and allowed for intralitter transmission. Direct contact between pups was not required for transmission indicating the importance of an environmental reservoir. An additional in vivo effect of pneumolysin was to enhance bacterial survival outside of the host. Our findings provide experimental evidence of a microbial strategy for transit to new hosts and explain why an organism expresses a toxin that damages the host upon which it depends.
authors.affiliation: Department of Microbiology, New York University, New York, NY 10016, USA.
authors.forename: M Ammar
authors.initials: MA
authors.lastname: Zafar
authors.affiliation: School of Medicine, Tsinghua University, 100084 Beijing, China; Department of Microbiology, New York University, New York, NY 10016, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Microbiology, New York University, New York, NY 10016, USA.
authors.forename: Shigeto
authors.initials: S
authors.lastname: Hamaguchi
authors.affiliation: Department of Microbiology, New York University, New York, NY 10016, USA. Electronic address: jeffrey.weiser@nyumc.org.
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Weiser
mesh_terms: D000818:Animals; D058491:Bacterial Load; D001426:Bacterial Proteins / Q000378:metabolism; D004195:Disease Models, Animal; D007249:Inflammation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011008:Pneumococcal Infections / Q000382:microbiology / Q000635:transmission*; D012137:Respiratory System / Q000276:immunology / Q000382:microbiology* / Q000473:pathology; D013296:Streptococcus pneumoniae / Q000472:pathogenicity*; D013301:Streptolysins / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D013301:Streptolysins; C032290:plY protein, Streptococcus pneumoniae
keywords: bacteria; colonization; infection; pneumococcus; pneumolysin; shedding; toxin; transmission