title: Reduction of chlortetracycline-resistant Escherichia coli in weaned piglets fed fermented liquid feed.
abstract: We investigated the change in chlortetracycline resistance in 360 Escherichia coli strains separated from the feces of piglets fed fermented liquid feed (FLF) in comparison with those fed dry feed (control). The total amount of lactic acid bacteria in feces was 8.77 x 10(8) CFU/g DM at weaning, which increased to 1.23 x 10(12) CFU/g DM (FLF) at 28 days after weaning (P<0.001). As a result of the antibiotic susceptibility test, almost all isolates were chlortetracycline-resistant (CTCR) until 14 days after weaning both in the FLF and control groups. At 28 days, the CTCR E. coli decreased to 22.2% in the FLF group, while the proportion of resistant bacteria was 88.9% in the control group. In addition, as a result of the gene analysis, it was clarified that there is a relation between the decrease in the minimum inhibitory concentration values and the possession rate of the tetracycline-resistance gene tet(A), tet(B) and tet(D). These results show that FLF caused an increase in the number of lactic acid bacteria in the intestines, and suggested that the feeding of FLF can possibly reduce antibiotic-resistance bacteria.
authors: National Institute of Livestock and Grassland Science, 2, Ikenodai, Tsukuba, Ibaraki 305-0901, Japan.
authors: Yuri
authors: Y
authors: Kobashi
authors: Hideyuki
authors: H
authors: Ohmori
authors: Kiyoshi
authors: K
authors: Tajima
authors: Tomoyuki
authors: T
authors: Kawashima
authors: Hiroo
authors: H
authors: Uchiyama
mesh_terms: D000821:Animal Feed; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002751:Chlortetracycline / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004032:Diet / Q000379:methods*; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification*; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D008137:Longitudinal Studies; D008826:Microbial Sensitivity Tests; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D002751:Chlortetracycline