[Elimination of multidrug resistance in E. coli in calves in vivo with rimactan]. / Eliminirane mngolekarstvenata rezistentnost na E., coli pri teleta in vivo s rimaktin.

An experiment was carried out for eliminating the multimedicinal resistance markers of E. coli, populating the intestinal tract of calves, in vivo with rimactan introduced per os, and rationed 10 mg/kg of live weight, once during a period of 8 days. The highest percentage and the longest elimination were observed for the neomycin, the novobiocin and the chlornitromycin resistance markers. The elimination was weaker for the erythromycin, the streptomycin and the kanamycin markers and the weakest was for the penicillin and tetracycline markers. There appeared a difference in the elimination of the resistance markers with the different calves, especially for the markers with a low degree of elimination, depending on the individual peculiarities of the calves. Riphamycin proved to be an eliminating means for the resistance markers of E coli in vivo of calves suffering from enteritis. Alongside with the elimination of the resistance markers, due to the treatment of calves with rimactan, an almost complete recovery was achieved. Rimactan is a reliable means for fighting enteric illnesses with calves, caused by enteropathogenic E. coli.

[Attempt at eliminating the multiple drug resistance of E. coli in pigs with enteritis using Rimactin]. / Opit za elimnirane s rimaktin mnogolekarstvenata ustoichivost na E. coli pri praseta s enterit.

The eliminating effect of rimactan was studied in vivo on resistance markers of E. coli, isolated from 18 new-born pigs with a clinic of enteritis. Rimactan is given per os in 15 mg/kg, liver weight, once a day in the course of 6 days. The sensitivity of the strains eliminated was checked in vitro in respect of 16 medicinal preparations (Pe, Sm, Km, Neo, Chl, Novo, Te, Er, Ty, Sp, Le, Am, Ox, Oxte, Ge-penicillin, streptomycin, kanamycin, neomycin, chlornitromycin, novobiocin, tetracycline, erythromycin, tylan, spectam, lentamycin, ampicillin, oxacillin, oxytetracycline, gentamicin and borgal). To 11 of them E. coli were resistant. After a treatment with rimactan an elimination of resistance markers was observed right on the first day, namely, with regard to Sm, Chl, Novo, Te, Er, Sp, Oxte. On the second day was eliminated the Pe-marker, on the third--the Ty-marker, and it was not until on the fifth day that Am and Ox-markers were eliminated. The elimination frequency was the highest between the third and the fifth days. The experiments studied also the sensitivity of the investigated coli strains with regard to different rimactan concentrations (2-256 mg/cm3) in vitro. It was most pronounced for a concentration of 16-32 mg/cm3. It was proved that rimactan can be used as a preparation for eliminating resistance markers (R-factors) of E. coli in pigs suffering from enteritis.