Plasmid incidence rate and conjugative chloramphenicol and tetracycline resistance plasmids in Malaysian isolates of Salmonella typhi.
Seven (6.1%) of 115 strains of Salmonella typhi isolated from Malaysian patients harbored a single large plasmid of 71 to 166 mD. Two of the seven plasmid-bearing strains were resistant to chloramphenicol (Cm) and tetracycline (Tc) and they transferred Cm and Tc resistance traits to Escherichia coli K12 at frequencies from 1.6 x 10(-7) to 1.9 x 10(-6). Agarose gel electrophoresis provided evidence that the resistance traits were cotransferred on a conjugative plasmid. The significance and importance of these results are discussed.
Phipps
M
M
Institute for Advanced Studies, University of Malaya, Kuala Lumpur.
Pang
T
T
Koh
C L
CL
Puthucheary
S
S
D002702:Chloramphenicol Resistance / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D008296:Malaysia; D010957:Plasmids; D012485:Salmonella typhi / Q000235:genetics*; D013753:Tetracycline Resistance / Q000235:genetics*