Studies with drug-resistant strains of psittacosis virus
| Autor: | Hermoise K. Mamay, Henry H. Bloom, Francis B. Gordon |
|---|---|
| Rok vydání: | 1960 |
| Předmět: |
Chlortetracycline
Drug Strain (chemistry) medicine.drug_class media_common.quotation_subject Antibiotics Lethal dose Embryo Drug resistance Sulfanilamide Biology medicine.disease Virology Psittacosis Virus Microbiology Penicillin Sulfadiazine medicine.anatomical_structure embryonic structures medicine Yolk sac media_common medicine.drug |
| Zdroj: | Virology. 11:486-498 |
| ISSN: | 0042-6822 |
| DOI: | 10.1016/0042-6822(60)90089-1 |
| Popis: | Three drug-resistant strains of psittacosis virus (Sa-r, sulfonamide-resistant; SaP-r, sulfonamide- and penicillin-resistant; Ctc-r, chlortetracycline-resistant) and one drug-susceptible strain (6BC) have been re-examined with respect to their drug resistance in chick embryo infections. Each drug resistance manifested itself in a manner somewhat different from the others. Resistance to sulfadiazine in Sa-r and SaP-r, and to penicillin in SaP-r, was virtually independent of the dose of drug used. The death of embryos infected with SaP-r was delayed 1 or 2 days by penicillin in a wide range of doses, but Sa-r in appreciable concentration killed embryos as promptly in the presence of sulfadiazine as in its absence. Resistance to chlortetracycline was dependent on the dose of drug when low concentrations of Ctc-r were used. SaP-r was shown to be resistant to sulfadiazine and penicillin together as well as to each alone. The marked differences in drug susceptibility allowed selection of drug dosages that permitted growth of resistant strains while effectively inhibiting susceptible strains. The limiting lethal dose of psittacosis virus for the chick embryo was found to be identical to the limiting infective dose, thus providing evidence that clones can be derived from appropriate harvests at the limiting dilution as determined by embryo deaths. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|