Dioctophyme renale: in vitro culture, production of excretory and secretory antigens, and their use in immunodiagnosis.

The nematode Dioctophyme renale affects mainly the right kidney of domestic and wild mammals, in addition to having zoonotic potential. Therefore, this study aimed to produce excretion and secretion antigens of adult D. renale (DES) to diagnose canine dioctophimosis. To obtain the excretion and secretion antigens (DES), five D. renale adults were maintained for three weeks in supplemented RPMI medium with weekly supernatant collections. After the DES concentration, 2200 mL of the collected supernatant was used, which was centrifuged, followed by two filtrations and dialyzed, resulting in 12.5 mL of DES with a protein concentration of 0.59 mg/mL. The polyacrylamide gel electrophoresis (SDS-PAGE) of the DES antigen showed fractions with molecular weights ranging from 30 to 250 Kda. In the indirect ELISA with the DES antigen, the mean absorbance of the positive sera (38) was 0.839 ± 0.267, and the mean of the negative control sera (7) was 0.208 ± 0.083; the specificity and sensitivity of the ELISA were 100 and 97.4 %, respectively, being as effective as the surgical method in the presence of viable parasites. Thus, for the first time, this study describes the production of excretion and secretion antigens of adult D. renale and standardizes an indirect ELISA to diagnose dioctophimosis.