title: Changing patterns of plasmid-mediated drug resistance during tetracycline therapy.
abstract: The patterns of drug resistance and the frequency of conjugative R plasmids in intestinal Escherichia coli from 88 patients treated for a skin disease (acne vulgaris) with low oral doses of tetracycline are reported. The proportion of patients with resistant bacteria was progressively greater in patients who received tetracycline for 1 week, 4 weeks, or longer (from 50 to 88%). No multiply drug-resistant bacteria were detected before treatment or after 1 week of treatment. After more than 4 weeks of treatment, multiply drug-resistant E. coli were isolated from about 50% of the patients. The origin and selection of R plasmid-determined multiple drug resistance are discussed.
mesh_terms: D000152:Acne Vulgaris / Q000188:drug therapy; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D005111:Extrachromosomal Inheritance; D005243:Feces / Q000382:microbiology; D006801:Humans; D010957:Plasmids; D011815:R Factors; D012393:Rosacea / Q000188:drug therapy; D013752:Tetracycline / Q000494:pharmacology / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D013752:Tetracycline