Apramycin Sulfate

Concentration addition (CA) is commonly used as a standard additive reference model to predict the short-term toxicity for most chemical mixtures. Whether CA can predict the long-term toxicity of antibiotic mixtures was investigated. The long-term toxicity of five antibiotics including apramycin sulfate, paromomycin sulfate, tetracycline hydrochloride, chloramphenicol and streptomycin sulfate and their mixtures to a photo bacterium Q67 were detected by the long-term toxicity microplate analysis procedure. Seven five-antibiotic mixtures with various concentration ratios and concentration levels were designed by employing uniform design ray method. The long-term mixture toxicity was predicted by CA based on the toxicity data of single antibiotics. The results showed that Weibull or Logit function fit well with the long-term toxicity data of all the components and their mixtures (R>0.98 and RMSE<0.07). According the toxicity index, the negative logarithm of mean effect concentration, the long-term toxicity of the five antibiotics differs greatly and is higher than their short-term toxicity. The predicted values by CA model conformed to the experimental values of mixtures, which implies CA can predict reliable results for the long-term toxicity of antibiotic mixtures.

The purpose of the present study was to examine the effect of apramycin sulphate on the colonization of pathogenic E. coli in the intestines of chicks. Apramycin treatment (0.5g/l in the drinking water) of 3-to 5-week-old Leghorn chicks for 24 or 48 hours resulted in a reduction, to an undetectable level, in the number of coliforms in the digestive tract for at least the first 24 h. Per os inoculation of E. coli (O2:K1) after 24 to 48 h of treatment resulted in a significant decrease in colony forming units (cfu) in the digestive tract of the treated chicks. Food deprivation from the time of inoculation did not significantly change the results. However, food and water deprivation caused bacteraemia in a number of the control chicks but not in the treated chicks. Comparison of the level of protection between Leghorn and broiler (Anak strain) chicks revealed that there was a significantly higher (P<0.05) level of bacteraemia in the broiler than in the Leghorn chicks. Chicks treated with 0.25 g/l or 0.125 g/l apramycin for 24 or 48 h before E. coli inoculation showed significantly lower cfu in the colon and caecum than untreated control chicks, but significantly higher cfu were found in the colon than in chicks treated with 0.

During 1983, a series of trials was carried out in Greece, Italy and Jordan, to test the efficacy of the aminocyclitol antibiotic apramycin as a treatment for naturally acquired Escherichia coli infections in broilers. The trials involved a total of 40,389 broilers, 27-39 days of age, in twelve houses at eight different production sites. Three levels of apramycin medication were evaluated: 125, 250 and 500 mg activity/litre drinking water, administered for five consecutive days. Treatment was only initiated after disease had been confirmed by laboratory examination of dead birds. Not all treatments were evaluated in every house. However, each house contained a group of unmedicated birds as controls, while the remaining birds were allocated to one or more apramycin treatment groups. There was a reduction in mortality and an improvement in the final weight and the economic feed conversion ratio in all three treatment groups. The data presented provide support for the use of apramycin sulphate administered in the drinking water for the treatment of E. coli infections in broilers.