Summary: Twelve thermosensitive H1 plasmids from strains of that had caused outbreaks of chloramphenicol-resistant typhoid fever in Vietnam, Thailand and India mediated citrate utilization (Cit) in a prototrophic 12 strain but not in the strains from which they were derived. Four H1 plasmids from a similar outbreak in Mexico differed from the Far Eastern plasmids in not mediating citrate utilization but in mediating mercury resistance. H1 plasmids resembling the Far Eastern and the Mexican plasmids in regard to citrate utilization and mercury resistance were found in sewage in Britain. Citrate utilization was transferred to eight pathogenic strains of and to one strain each of and Cultures of Cit bacteria grew more rapidly in citrate media at 28°C than at 37°C. Plasmid mutants that were more efficient at utilizing citrate were present in all such cultures-they grew equally well or better at 37°C than at 28°C. None of 222 strains of or that contained a variety of different plasmids were able to utilize citrate. This property was not transferred to the prototrophic 12 strain from (3 strains), (39 strains), (44 strains), (33 strains) or (44 strains).


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error