Abstract
Germ-free mice were colonized with a pigmented, tetracycline-sensitive strain of Staphylococcus aureus and maintained in flexible plastic isolators. Treatment of the gnotobiotic mice with oral tetracycline (20 mg/ml) resulted in the development of staphylococci resistant to tetracycline (5 μg/ml or higher). Resistant staphylococci did not appear in feces until several days after exposure of mice to the antibiotic and persisted for as long as specimens were collected (64 days subsequently). Resistance developed after a single exposure of gnotobiotes to antibiotic. Resistant staphylococci were present in the intestinal tracts of mice at counts of 103 per g of contents, whereas sensitive organisms coexisted at counts of 105 to 1011 per g. Resistant staphylococci were isolated only from treated mice and not from untreated mice in adjacent cages. Initial colonization of germ-free mice with sensitive staphylococci interfered with subsequent colonization by resistant staphylococci and provided an example of bacterial interference. Resistance to tetracycline was not associated with resistance to chloramphenicol, penicillin, ampicillin, erythromycin, streptomycin, or kanamycin. Hydrolysis of gelatin was the only biochemical characteristic in which isolates varied but was not correlated with resistance to tetracycline or pigmentation of colonies. A nonpigmented, gray variant of S. aureus appeared in all specimens after colonization with the original, pigmented strain. Only the nonpigmented strain was obtained from gnotobiotes colonized with the nonpigmented variant. Contact between bacteria and antibiotic in the intestinal tract of gnotobiotes was considered to be essential for the development of tetracycline-resistant staphylococci.
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- Abrams G. D., Bishop J. E. Effect of the normal microbial flora on gastrointestinal motility. Proc Soc Exp Biol Med. 1967 Oct;126(1):301–304. doi: 10.3181/00379727-126-32430. [DOI] [PubMed] [Google Scholar]
- Asheshov E. H. Loss of antibiotic resistance in Staphylococcus aureus resulting from growth at high temperature. J Gen Microbiol. 1966 Mar;42(3):403–410. doi: 10.1099/00221287-42-3-403. [DOI] [PubMed] [Google Scholar]
- De Courcy S. J., Jr, Sevag M. G. Specificity and prevention of antibiotic resistance in Staphylococcus aureus. Nature. 1966 Jan 22;209(5021):373–376. doi: 10.1038/209373a0. [DOI] [PubMed] [Google Scholar]
- FINLAND M. Emergence of antibiotic-resistant bacteria. N Engl J Med. 1955 Dec 8;253(23):1019–concl. doi: 10.1056/NEJM195512082532306. [DOI] [PubMed] [Google Scholar]
- GIBBONS R. J., SOCRANSKY S. S., KAPSIMALIS B. ESTABLISHMENT OF HUMAN INDIGENOUS BACTERIA IN GERM-FREE MICE. J Bacteriol. 1964 Nov;88:1316–1323. doi: 10.1128/jb.88.5.1316-1323.1964. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Inoue M., Hashimoto H., Mitsuhashi S. Mechanism of tetracycline resistance in Staphylococcus aureus. I. Inducible resistance to tetracycline. J Antibiot (Tokyo) 1970 Feb;23(2):68–74. doi: 10.7164/antibiotics.23.68. [DOI] [PubMed] [Google Scholar]
- LINDSEY D. Quantitative bacteriologic study of tissues, fluids, and exudates; some simplified methods. J Lab Clin Med. 1959 Feb;53(2):299–307. [PubMed] [Google Scholar]
- MAY J. W., HOUGHTON R. H., PERRET C. J. THE EFFECT OF GROWTH AT ELEVATED TEMPERATURES ON SOME HERITABLE PROPERTIES OF STAPHYLOCOCCUS AUREUS. J Gen Microbiol. 1964 Nov;37:157–169. doi: 10.1099/00221287-37-2-157. [DOI] [PubMed] [Google Scholar]
- Parisi J. T., Kiley M. P. Components in brain heart infusion selective for chromogenic variants of Staphylococcus aureus. Can J Microbiol. 1970 Feb;16(2):91–94. doi: 10.1139/m70-016. [DOI] [PubMed] [Google Scholar]
- SHINEFIELD H. R., RIBBLE J. C., BORIS M., EICHENWALD H. F. Bacterial interference: its effect on nursery-acquired infection with Staphylococcus aureus. I. Preliminary observations on artificial colonzation of newborns. Am J Dis Child. 1963 Jun;105:646–654. [PubMed] [Google Scholar]

