Resident microbiota affect Bordetella pertussis infectious dose and host specificity.
Before contacting host tissues, invading pathogens directly or indirectly interact with host microbiota, but the effects of such interactions on the initial stages of infection are poorly understood. Bordetella pertussis is highly infectious among humans but requires large doses to colonize rodents, unlike a closely related zoonotic pathogen, Bordetella bronchiseptica, raising important questions about the contributions of bacterial competition to initial colonization and host selection. We observed that <100 colony-forming units (CFU) of B. bronchiseptica efficiently infected mice and displaced culturable host microbiota, whereas 10 000 CFU of B. pertussis were required to colonize murine nasal cavities and did not displace host microorganisms. Bacteria isolated from murine nasal cavities but not those from the human lower respiratory tract limited B. pertussis growth in vitro, indicating that interspecies competition may limit B. pertussis colonization of mice. Further, a broad-spectrum antibiotic treatment delivered before B. pertussis inoculation reduced the infectious dose to <100 CFU, and reintroduction of single Staphylococcus or Klebsiella species was sufficient to inhibit B. pertussis colonization of antibiotic-treated mice. Together, these results reveal that resident microorganisms can prevent B. pertussis colonization and influence host specificity, and they provide rationale for manipulating microbiomes to create more-accurate animal models of infectious diseases.
Department of Veterinary and Biomedical Sciences.
Laura S
LS
Weyrich
Heather A
HA
Feaga
Jihye
J
Park
Sarah J
SJ
Muse
Chetan Y
CY
Safi
Olivier Y
OY
Rolin
Sarah E
SE
Young
Eric T
ET
Harvill
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001885:Bordetella Infections / Q000382:microbiology*; D016950:Bordetella bronchiseptica / Q000187:drug effects / Q000302:isolation & purification / Q000472:pathogenicity; D001886:Bordetella pertussis / Q000187:drug effects / Q000302:isolation & purification / Q000472:pathogenicity*; D058507:Host Specificity; D006801:Humans; D007709:Klebsiella / Q000187:drug effects / Q000502:physiology; D008810:Mice, Inbred C57BL; D056265:Microbial Interactions / Q000187:drug effects / Q000502:physiology*; D064307:Microbiota / Q000187:drug effects / Q000502:physiology*; D009296:Nasal Cavity / Q000382:microbiology; D010802:Phylogeny; D013183:Sputum / Q000382:microbiology; D013210:Staphylococcus / Q000187:drug effects / Q000502:physiology; D014917:Whooping Cough / Q000382:microbiology
D000900:Anti-Bacterial Agents
Bordetella; antibiotics; bacterial competition; host adaptation; interspecies competition; microbiome; pathogen evolution; whooping cough