Efficacy of sulbactam-ampicillin in the treatment of neonatal calf diarrhoea

Abstract

Sulbactam-ampicillin is a combination of sulbactam, a beta-lactamase inhibitor, and ampicillin, a broad spectrum beta-lactam antibiotic. The efficacy of sulbactam-ampicillin was evaluated in the treatment of neonatal calf diarrhoea under conditions where a major proportion of the calves were excreting enterobacteria which were resistant to beta-lactam antibiotics. In a series of six studies with a common experimental design, three treatments (sulbactam-ampicillin, ampicillin alone and untreated control) were compared in over 300 Friesian and Ayrshire calves aged between three and 10 days and of known immunological status as determined by their zinc sulphate turbidity values. A mortality rate of 26.4 per cent in the negative control calves was reduced to 14.0 per cent with ampicillin alone and 9.5 per cent with sulbactam-ampicillin. The probability of diarrhoea subsequent to initiation of treatment was reduced from 0.50 in the negative control calves to 0.44 with ampicillin alone and 0.35 with sulbactam-ampicillin. The differences in mortality and diarrhoea observed between the calves treated with sulbactam-ampicillin and the calves in each of the other treatment groups were statistically significant. The superior efficacy of sulbactam-ampicillin is explained by the inhibitory effect of sulbactam on the beta-lactamases produced by resistant bacteria, thus rendering them susceptible to the ampicillin in the combination.

Antimicrobial Use in the Treatment of Calf Diarrhea

“…37 Ampicillin (12 mg/kg PO q12h for 3-5 days) had no effect (P ϭ .83) on mortality rate (26/83 ϭ 31% in ampicillin-treated calves; 27/82 ϭ 33% in control calves). Lack of treatment success in this 1975 study was later attributed to a delay in instituting antimicrobial treatment 38 ; antimicrobials were not administered until diarrhea had been present for a number of days. In the same year, a large study was conducted in Europe involving 347 male dairy calves with diarrhea.…”

“…Another seminal study was conducted in 1987 at multiple locations in Europe involving 318 diarrheic calves. 38 Calves were randomly assigned to 1 of 3 treatment groups: sulbactam-ampicillin (9.9 mg/kg IM q24h; 10/105 ϭ 10% mortality), ampicillin (6.6 mg/kg IM q24h; 15/107 ϭ 14% mortality), or untreated control (28/106 ϭ 26% mortality). Treatment was instituted immediately on detection of diarrhea.…”

“…The study also indicated that administration of sulbactam (penicillinic acid sulfone), which is a potent irreversible inhibitor of ␤-lactamase, increased the treatment efficacy of parenteral ampicillin. 38 Parenteral administration of apramycin or the ␤-lactam antimicrobial ampicillin was effective in treating naturally acquired diarrhea, and treatment efficacy of ampicillin was increased with ␤-lactamase inhibition.…”

“…Another recommended treatment is parenteral amoxicillin trihydrate or ampicillin trihydrate (10 mg/kg IM q12h) for at least 3 days. Although parenteral ampicillin has proven efficacy in treating naturally acquired diarrhea, 38 whereas ceftiofur has unproven efficacy, the broad-spectrum ␤-lactam antimicrobials amoxicillin and ampicillin are theoretically inferior to ceftiofur because parenterally administered ampicillin and amoxicillin reach lower plasma concentrations, require a higher MIC than ceftiofur, and are not ␤lactamase resistant. 61 Amoxicillin or ampicillin should be injected into the neck musculature because this site provides the greatest absorption 62 and minimizes damage to more valuable areas of the carcass.…”

Newborn calf welfare: A review focusing on mortality rates

“…Therapeutic and prophylactic effects of all sorts of antibiotics have been demonstrated (Grimshaw et al . ). The advantage of anthelmintic treatments first at 3 weeks of age is seen as a reduction in the combined morbidity/mortality rate in buffalo calves (Srikitjakarn et al .…”