Fosfomycin in vivo penetration in swine intestinal cells

Abstract

Enteric diseases have a high economic impact on animal production, being the interstitial and intracellular fluids, the main sites of infection (biophase) of the pathogens responsible for these disorders. Fosfomycin is an antibiotic widely used for the treatment and prevention of swine infections caused by resistant bacteria. For most of the important pathogens in swine production, fosfomycin MIC90 has been established in 0.25-4 µg/mL. Calcium fosfomycin concentrations in swine intestinal cells were previously determined by in vitro and ex vivo studies, although, still now, there are no in vivo studies showing the exposure of minimum inhibitory concentrations of fosfomycin in the enteric infectious site. According to this background, the aim of this research was to determine in vivo calcium fosfomycin concentrations on swine intestinal cells. Four clinically healthy post-weaning piglets 4-5 weeks old were used. Animals were sacrificed after 15 days of calcium fosfomycin consumption in the drinking water (30 mg/kg). After slaughtering, jejunum was removed. Intracellular concentrations of the antibiotic were analyzed by HPLC MS/MS and they ranged from 0.82 to 2.05 µg/mL. These concentrations exceed the MIC90 of intestinal pathogens such as E.coli (0.5 μg/mL), although they are lower than the MIC90 of Salmonella enterica (4 μg/mL).