Natural habitat of Caryophanon latum.

Abstract

When samples of fresh dung from pigs, horses, sheep, or cattle were enriched to encourage the growth of Caryophanon latum, the organism was found to be specifically associated with cattle dung. Several sheep dung samples were found to be positive for C. latum, but all were taken from a pasture where sheep and cattle were grazed together. All samples taken from sheep not pastured with cattle were negative. Autoclaved samples of cattle, horse, and sheep dung all supported growth and natural morphology of C. latum when inoculated with pure or mixed cultures of this organism. A large proportion of autoclaved cattle dung samples left open to the air of cattle barns or occupied cattle pastures showed the presence of C. latum after 1–4 days exposure. Control samples exposed to air in areas far removed from cattle were uniformly negative. Aseptically collected "free catch" samples from cattle were mainly negative, as were samples collected from the fistulated rumen. Enrichment of various other sources was undertaken. Our total findings support the hypothesis that C. latum is a natural, specific, and temporary resident of cattle dung and is dispersed to new droppings by contaminated air and also probably by flying insects or cattle movement.