Hydrogen sulfide-producing variants of Escherichia coli.

Seventeen strains of H(2)S-producing variants of Escherichia coli were isolated from specimens submitted for microbiological study (ten from stool, five from urine, and two from postmortem material). Production of H(2)S was unstable in several strains; however, other than their production of H(2)S, all strains closely resembled typical E. coli in their biochemical reactions. In vitro susceptibilities of the H(2)S-producing variants to antimicrobics closely resembled those of typical E. coli in this laboratory.