No abstract

Occurrence of methane in gas from the human intestine is evidence that methanogenic organisms grow in the human alimentary tract. Both hydrogen and methane can be detected in the respired air of many humans (1). This note reports the results of experiments to detect methanogenic bacteria in feces and to isolate them in pure culture.

No abstract

The postomortem invasion of muscle and other tissues by bacteria from the intestinal tract was studied with the use of radioactive tracers. The injection of 14C-labeled bacteria or spores into the intestines of guinea pig carcasses within 24 h of death resulted in the rapid spread of 14C throughout carcasses. When live bacteria were injected along with the labeled cells, it was not possible to isolate viable organisms from the body tissues if the living animal had been exposed to the bacteria. It appears that animals are immune to their normal intestinal flora and that this immunity persists after death; thus passage of these bacteria into the lymphatic system does not necessarily result in the presence of live bacteria in carcass tissues. It therefore seems that a delay of up to 24 h before evisceration would not lead to deep tissue contamination of the carcass by organisms usually present in the intestines. Further evidence for this hypothesis was obtained by showing that muscle and lymph nodes from uneviscerated lamb carcasses hung for 24 h at 20 C remained sterile.

A methanogenic enrichment culture decomposed small concentrations of 14C benzoate to 14C4 and 14C02 under stringently anaerobic conditions with or without preceding exposure to benzoate.