Estudo farmacocinético de nanopartículas poliméricas de cloxacilina administradas em cabras Toggenburg naturalmente infectadas por Corynebacterium pseudotuberculosis

Abstract

Caseous lymphadenitis is an infectious and zoonotic disease caused by the facultative intracellular bacteria Corynebacterium pseudotuberculosis. The condition affects small ruminants worldwide, causing significant reduction in milk, wool and meat production. Considering the current therapeutic approaches, encapsulated lesions on superficial lymph nodes are the most important barrier for penetration of antibiotics into the infection site. Accordingly, the objective of this study was to evaluate the pharmacokinetics of cloxacillin-loaded polymeric nanospheres (CLXNP). Ten Toggenburg female goats, naturally infected with C. pseudotuberculosis, were distributed into four groups, according to the drainage time of the abscess content: 3, 6, 24 and 48 hours after subcutaneous administration of 1.81 mg/kg of CLXNP in the peri- abscess region. CLXNP exhibited sizes of 188.41 ± 49.34 nm, polydispersity index of 0.181 ± 0.07 and zeta potential of -33.93 ± 6.42 mV. At the in vitro assay, for 4 µg/ml of CLXNP there was a reduction of 96.5 and 89 % in bacterial count at intracellular and extracellular compartments, respectively. Cloxacillin concentration in the abscess was much higher than the in vitro inhibitory concentration, even after the antibiotic was no longer detected in the circulatory system. The data are promising for the development of an alternative therapeutic approach.