The endozoan, small-mammal reservoir hypothesis and the life cycle of Coccidioides species

John W. Taylor, Bridget M. Barker

Research output: Contribution to journalArticlepeer-review

26 Scopus citations

Abstract

The prevailing hypothesis concerning the ecology of Coccidioides immitis and C. posadasii is that these human pathogenic fungi are soil fungi endemic to hot, dry, salty regions of the New World and that humans and the local, small-mammal fauna are only accidental hosts. Here we advance an alternative hypothesis that Coccidioides spp. live in small mammals as endozoans, which are kept inactive but alive in host granulomas and which transform into spore-producing hyphae when the mammal dies. The endozoan hypothesis incorporates results from comparative genomic analyses of Coccidioides spp. and related taxa that have shown a reduction in gene families associated with deconstruction of plant cell walls and an increase in those associated with digestion of animal protein, consistent with an evolutionary shift in substrate from plants to animals. If true, the endozoan hypothesis requires that models of the prevalence of human coccidioidomycosis account not only for direct effects of climate and soil parameters on the growth and reproduction of Coccidioides spp. but also consider indirect effects on these fungi that come from the plants that support the growth and reproduction of the small mammals that, in turn, support these endozoic fungi.

Original languageEnglish (US)
Pages (from-to)S16-S20
JournalMedical Mycology
Volume57
DOIs
StatePublished - Jan 25 2019

Keywords

  • Coccidioides
  • animal reservoir
  • coccidioidomycosis
  • endozoan
  • life cycle

ASJC Scopus subject areas

  • Infectious Diseases

Fingerprint

Dive into the research topics of 'The endozoan, small-mammal reservoir hypothesis and the life cycle of Coccidioides species'. Together they form a unique fingerprint.

Cite this