Characterization of mutations in the rpoB gene in naturally rifampin-resistant Rickettsia species.
Rickettsiae are gram-negative, obligately intracellular bacteria responsible for arthropod-borne spotted fevers and typhus. Experimental studies have delineated a cluster of naturally rifampin-resistant spotted fever group species. We sequenced the 4, 122- to 4,125-bp RNA polymerase beta-subunit-encoding gene (rpoB) from typhus and spotted fever group representatives and obtained partial sequences for all naturally rifampin-resistant species. A single point mutation resulting in a phenylalanine-to-leucine change at position 973 of the Rickettsia conorii rpoB sequence and present in all the rifampin-resistant species was absent in all the rifampin-susceptible species. rpoB-based phylogenetic relationships among these rickettsial species yielded topologies which were in accordance with previously published phylogenies.
Drancourt
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M
Unité des Rickettsies CNRS UPRES-A 6020, Faculté de Médecine, Université de la Méditerranée, 13385 Marseille Cedex 05, France.
Raoult
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D
D000904:Antibiotics, Antitubercular / Q000494:pharmacology; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D012281:Rickettsia / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D012293:Rifampin / Q000494:pharmacology*; D012373:Rocky Mountain Spotted Fever / Q000382:microbiology
D000904:Antibiotics, Antitubercular; D012321:DNA-Directed RNA Polymerases; C105078:RNA polymerase beta subunit; D012293:Rifampin