Visceral infection by Porocephalus spp. (Pentastomida) in Neotropical wild mammals.

Larval stages of pentastomids were collected from different organs of small mammals from the Peruvian Amazon. These parasitized mammals included: a western Amazonian oryzomys (Hylaeamys perenensis), an elegant oryzomys (Euryoryzomys nitidus), a lowland paca (Cuniculus paca), two kinkajous (Potos flavus), two silvery woolly monkeys (Lagothrix poeppigii) and a brown-mantled tamarin (Leontocebus fuscicollis). Pentastomids were found in the mesentery and parenchyma of the liver and lungs of these animals. All pentastomids were morphologically identified as nymphs of Porocephalus spp. Only the nymphs collected from select animals (the western Amazonian oryzomys, the elegant oryzomys and the brown-mantled tamarin) were analysed molecularly. Molecular analysis was performed amplifying the mitochondrial cytochrome c oxidase subunit I gene from select nymphs collected from the western Amazonian oryzomys, the elegant oryzomys and the brown-mantled tamarin. The nucleotide sequences exhibited 95.8-97.7% similarity between them. Also, these sequences showed an identity of 95.8-97.9% to Porocephalus crotali (GenBank accession numbers MG559647-MG559655). Molecular analysis indicated the presence of at least two Porocephalus species. These findings represent the first record of Porocephalus in these mammals, thus adding new intermediate hosts for this pentastomid genus. This work represents the first molecular data of Porocephalus in a Neotropical climate.

A high oxfendazole dose to control porcine cysticercosis: pharmacokinetics and tissue residue profiles.

Oxfendazole (OFZ) is efficacious for porcine cysticercosis at 30 mg/kg. OFZ is not registered to be used at this dose. The assessment of the OFZ and metabolites [(fenbendazole sulphone (FBZSO2), fenbendazole (FBZ)] plasma pharmacokinetic and tissue residue profiles after its oral administration to pigs and the withdrawal period for human consumption were reported. Forty-eight pigs allocated into two groups received OFZ (30 mg/kg) orally as a commercial (CF) or as experimental formulation (SMF). Samples (blood, muscle, liver, kidney and fat) were collected over 30 days post-treatment and analyzed by HPLC. OFZ was the main compound recovered in plasma, followed by FBZSO2 and low FBZ concentrations. OFZ AUC0-LOQ (209.9±33.9 µg·h/ml) and Cmax (5.40±0.65 µg/ml) parameters for the CF tended to be higher than those for the SMF (AUC0-LOQ: 159.4±18.3 µg h/ml, Cmax: 3.80±0.35 µg/ml). The highest total residue (OFZ+FBZSO2+FBZ) concentrations were quantified in liver, followed by kidney, muscle and fat tissue. FBZSO2 residue levels were the highest found in muscle (0.68±0.39 µg/g) and fat (0.69±0.39 µg/g). In liver and kidney the highest residues corresponded to FBZ (5.29±4.36 µg/g) and OFZ (2.86±0.75 µg/g), respectively. A withdrawal time of 17 days post-treatment was established before tissues are delivered for human consumption.