title: In vivo R-plasmid transfer in a patient with a mixed infection of shigella dysentery.
abstract: Transfer of shigella R-plasmids in vivo has seldom been demonstrated. Strains of Shigella dysenteriae type 1 and Shigella flexneri type 5b were isolated from a Bulgarian traveller who visited Vietnam and developed dysentery, which was treated with trimethoprim/sulfamethoxazole (TMP/SMZ) for a short time. Both species of shigellae are unusual in Bulgaria where strains of S. sonnei predominate. Both shigella strains were multiresistant to the same antimicrobial agents. Each strain contained a 48-kilobase plasmid that conferred the entire resistance phenotype to a susceptible Escherichia coli. Restriction endonuclease patterns of plasmid DNA from the respective strains were identical. Transmissible plasmids of the same resistance phenotypes and restriction patterns were isolated from the patient's colonic E. coli. Transconjugants hybridized to a dihydrofolate reductase type I-DNA probe. These studies support the hypothesis that R-plasmid transfer may occur between non-pathogenic, faecal strains and pathogenic shigellae, a process that may have been facilitated by inadequate treatment with TMP/SMZ at the onset of the illness.
authors.affiliation: Department of Medicine, Medical University of South Carolina, Charleston.
authors.forename: M P
authors.initials: MP
authors.lastname: Bratoeva
authors.forename: J F
authors.initials: JF
authors.lastname: John
mesh_terms: D000368:Aged; D003227:Conjugation, Genetic / Q000235:genetics*; D015342:DNA Probes; D004405:Dysentery, Bacillary / Q000188:drug therapy / Q000382:microbiology*; D004926:Escherichia coli / Q000235:genetics*; D006801:Humans; D008297:Male; D010641:Phenotype; D011815:R Factors / Q000235:genetics*; D015183:Restriction Mapping; D012703:Serotyping; D012762:Shigella dysenteriae / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D012763:Shigella flexneri / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D013762:Tetrahydrofolate Dehydrogenase; D014195:Travel; D014296:Trimethoprim Resistance / Q000235:genetics*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use
chemical_list: D015342:DNA Probes; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D013762:Tetrahydrofolate Dehydrogenase