Abstract
Four recently weaned pigs were dosed orally with oxytetracycline. This caused a rapid increase in the incidence of tetracycline resistance (TcR) among Escherichia coli isolates from the faecal flora. The isolates were differentiated further on the basis of O-serogroup, biotype and resistance pattern. There was no evidence that the administration of the antibiotic selected for a few TcR clones, but rather a relatively large number of TcR strains were identified during the dosing period. Using selective isolation media a proportion of these strains were demonstrated in the minority faecal Esch. coli flora before dosing, while the remainder were recognized for the first time after dosing commenced. The incidence of TcR among Esch. coli isolates also increased after weaning in other pigs which were not dosed with oxytetracycline or any other antibacterial agent. In a proportion of these animals this increase was associated with the dominance of a TcR enteropathogenic serotype (0149:K 91, K 88a, c) in the faecal Esch. coli flora which was probably ingested in small numbers before weaning. The source of other TcR strains was probably the environment in which each pig was placed after weaning.
Full text
PDF








Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Chopra I., Howe T. G., Linton A. H., Linton K. B., Richmond M. H., Speller D. C. The tetracyclines: prospects at the beginning of the 1980s. J Antimicrob Chemother. 1981 Jul;8(1):5–21. doi: 10.1093/jac/8.1.5. [DOI] [PubMed] [Google Scholar]
- Finlayson M., Barnum D. A. The effect of chlortetracycline feed additive on experimental salmonella infection of swine and antibiotic resistance transfer. Can J Comp Med. 1973 Apr;37(2):139–146. [PMC free article] [PubMed] [Google Scholar]
- Hartley C. L., Howe K., Linton A. H., Linton K. B., Richmond M. H. Distribution of R plasmids among the O-antigen types of Escherichia coli isolated from human and animal sources. Antimicrob Agents Chemother. 1975 Aug;8(2):122–131. doi: 10.1128/aac.8.2.122. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hinton M., Allen V., Linton A. H. The biotyping of Escherichia coli isolated from healthy farm animals. J Hyg (Lond) 1982 Jun;88(3):543–555. doi: 10.1017/s0022172400070406. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hinton M., Linton A. H. Antibacterial drug resistance among Escherichia coli isolated from calves fed on a milk substitute diet. Vet Rec. 1983 Jun 11;112(24):567–568. doi: 10.1136/vr.112.24.567. [DOI] [PubMed] [Google Scholar]
- Hinton M., Linton A. H., Hedges A. J. The ecology of Escherichia coli in calves reared as dairy-cow replacements. J Appl Bacteriol. 1985 Feb;58(2):131–138. doi: 10.1111/j.1365-2672.1985.tb01439.x. [DOI] [PubMed] [Google Scholar]
- Jackson G. A survey of antibiotic resistance of Escherichia Coli isolated from farm animals in Great Britain from 1971 to 1977. Vet Rec. 1981 Apr 11;108(15):325–328. doi: 10.1136/vr.108.15.325. [DOI] [PubMed] [Google Scholar]
- Kenworthy R., Allen W. D. The significance of Escherichia Coli to the young pig. J Comp Pathol. 1966 Jan;76(1):31–44. doi: 10.1016/0021-9975(66)90045-4. [DOI] [PubMed] [Google Scholar]
- Langlois B. E., Cromwell G. L., Hays V. W. Influence of type of antibiotic and length of antibiotic feeding period on performance and persistence of antibiotic resistant enteric bacteria in growing-finishing swine. J Anim Sci. 1978 May;46(5):1383–1396. doi: 10.2527/jas1978.4651383x. [DOI] [PubMed] [Google Scholar]
- Langlois B. E., Cromwell G. L., Stahly T. S., Dawson K. A., Hays V. W. Antibiotic resistance of fecal coliforms after long-term withdrawal of therapeutic and subtherapeutic antibiotic use in a swine herd. Appl Environ Microbiol. 1983 Dec;46(6):1433–1434. doi: 10.1128/aem.46.6.1433-1434.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Linton A. H. Antibiotic resistance: the present situation reviewed. Vet Rec. 1977 Apr 23;100(17):354–360. doi: 10.1136/vr.100.17.354. [DOI] [PubMed] [Google Scholar]
- Linton A. H., Handley B., Osborne A. D. Fluctuations in Escherichia coli O-serotypes in pigs throughout life in the presence and absence of antibiotic treatment. J Appl Bacteriol. 1978 Apr;44(2):285–298. doi: 10.1111/j.1365-2672.1978.tb00801.x. [DOI] [PubMed] [Google Scholar]
- Linton A. H. Has Swann failed? Vet Rec. 1981 Apr 11;108(15):328–331. doi: 10.1136/vr.108.15.328. [DOI] [PubMed] [Google Scholar]
- Linton A. H., Howe K., Osborne A. D. The effects of feeding tetracycline, nitrovin and quindoxin on the drug-resistance of coli-aerogenes bacteria from calves and pigs. J Appl Bacteriol. 1975 Jun;38(3):255–275. doi: 10.1111/j.1365-2672.1975.tb00530.x. [DOI] [PubMed] [Google Scholar]
- Miller B. G., Newby T. J., Stokes C. R., Bourne F. J. Influence of diet on postweaning malabsorption and diarrhoea in the pig. Res Vet Sci. 1984 Mar;36(2):187–193. [PubMed] [Google Scholar]
- Rollins L. D., Gaines S. A., Pocurull D. W., Mercer H. D., Frobish L. T. Persistence of transferable drug resistance in the lactose-fermenting enteric flora of swine following antimicrobial feeding. Can J Comp Med. 1976 Apr;40(2):175–183. [PMC free article] [PubMed] [Google Scholar]
- Smith H. W., Lovell M. A. Escherichia coli resistant to tetracyclines and to other antibiotics in the faeces of U.K. chickens and pigs in 1980. J Hyg (Lond) 1981 Dec;87(3):477–483. doi: 10.1017/s0022172400069722. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith H. W. Persistence of tetracycline resistance in pig E. coli. Nature. 1975 Dec 18;258(5536):628–630. doi: 10.1038/258628a0. [DOI] [PubMed] [Google Scholar]