Colony incompatibility among strains of Escherichia coli isolated during an outbreak of gastroenteritis in one ward.

Strains of Escherichia coli, isolated during an outbreak of infantile gastroenteritis in one ward were serotyped and tested for incompatibility against each other on semisolid agar. Serotypes commonly isolated in various parts of the world from various habitats showed a greater incompatibility than more rarely isolated serotypes, suggesting that the former may have a selective advantage and be more able to displace other serotypes in a given habitat.