title: ["Salmonella typhi" resistant to chloramphenicol isolated north of Lisbon (author's transl)].
abstract: Thirteen strains of Salmonella typhi phage type A/Tan isolated in a typhoid endemic zone north to Lisbon (November 1977-June 1979) showed a low chloramphenicol resistance (MIC = 32 microgram/ml). None of these strains could transfer chloramphenicol resistance at 28 or 37 degrees C. Production of chloramphenicol-acetyl-transferase by these strains could not be demonstrated. No extrachromosomal DNA was detected by agarose-gel electrophoresis. A chromosomal resistance mechanism is postulated which could act on the permeation system.
mesh_terms: D000123:Acetyltransferases / Q000378:metabolism; D002701:Chloramphenicol / Q000378:metabolism / Q000494:pharmacology*; D003227:Conjugation, Genetic; D004352:Drug Resistance, Microbial; D006801:Humans; D010957:Plasmids; D011174:Portugal; D012485:Salmonella typhi / Q000145:classification / Q000187:drug effects* / Q000201:enzymology
chemical_list: D002701:Chloramphenicol; D000123:Acetyltransferases
vernacular_title: Résistance de Salmonella typhi au chloramphénicol dan une région au nord de Lisbonne.