Partial purification and characterization of Gastrothylax crumenifer somatic antigens

Isolation and immunoblotting of somatic antigens of Cotylophoron cotylophorum and Gastrothylax crumenifer

Paramphistomosis is the emerging fluke infection in young ruminants which results in high morbidity and mortality in tropics and sub-tropics. The present study was carried out to detect the sharing antigens among the purified somatic antigens of G. crumenifer and C. cotylophorum, in  order to use as a candidate antigen for diagnosis of paramphistomosis in sheep. Immunoblot analysis of the purified somatic antigens of C. cotylophorum and G. crumenifer using their specific rabbit hyper immune serum revealed 3 common polypeptides at the range of 27, 29 and 60 kDa. Hence these three immunodominant peptides can be used candidate antigens in development of vaccines against ovine paraphistomosis and also for early diagnosis of infection.

Identification of immunodominant fraction of Paramphistomum epiclitum and its evaluation for use in the serodiagnosis of paramphistomosis by ELISA

The present study was undertaken to identify and purify the immunodominant fractions from the excretorysecretory (ES) antigen of Paramphistomum epiclitum, a predominant amphistome species infecting ruminants inIndia. ES antigen was prepared and characterized using SDS-PAGE and Western blot analysis. Major polypeptidesof molecular weight 11, 22, 28, 31, 33, 39, 52, 59, 63 and 72 kDa were visualized in SDS-PAGE. Polypeptides (9)of 11, 14, 16, 22, 31, 33, 39, 63 and 72 kDa showed immunoreactivity in Western blot analysis. The whole ESantigen of P. epiclitum was initially concentrated using PEG-8000 followed by spin-X UF concentrator with 10kDa cutoff range and subsequently fractionated by size exclusion chromatography using Sephadex G-25. Crossreactivity of the P. epiclitum ES antigen was studied with positive sera of F. gigantica and H. contortus. Based onthe cross reactivity profile, the low molecular weight antigenic fraction with 11 kDa polypeptide was selected forfurther use in indirect-ELISA. Bovine serum samples (258) were tested with optimized ELISA. Sensitivity of theELISA was calculated as 75.0%, while the specificity was 85.0%. The percent positive and negative predictivevalues for the test were 70.78 and 87.57%, respectively.

Preparation and characterization of excretory and secretory antigen of Cotylophoron cotylophorum and Gastrothylax crumenifer

Excretory and secretory antigen of adult Cotylophoron cotylophorum and Gastrothylax crumenifer was prepared and characterized by SDS-PAGE. Adult paramphistomes were collected in PBS from rumen of sheep slaughtered at Perambur and Villivakkam slaughter houses, Chennai, Tamil Nadu. Excretory/Secretory (E/S) antigens of G. crumenifer and C. cotylophorum were prepared by incubating in PBS at 28.3 °C overnight in a shaking incubator and centrifuged. The culture supernatant was used as antigen. The protein concentration of E/S antigens of C. cotylophorum and G. crumenifer ranged from 0.4 to 7.1 mg/ml and 3.3 to 5.9 mg/ml, respectively. SDS-PAGE analysis of E/S antigen of C. cotylophorum revealed two polypeptide bands from the range of 32 and 40 kDa. Whereas, SDS-PAGE analysis of E/S antigen of G. crumenifer revealed only one polypeptide band of 35 kDa. Excretory/secretory antigen may be used for serodiagnosis of paramphistomosis infection in sheep.

Evaluation of antibody response to various developmental stage specific somatic antigens of Paramphistomum epiclitum in goats

Electrophoretic analysis of various developmental stage specific somatic antigens of Paramphistomum epiclitum (Digenea: Paramphistomidae), namely, metacercariae (McAg), immature intestinal flukes (ImIAg), immature ruminal flukes (ImRAg), and adult flukes (AAg), was done by native polyacrylamide gel electrophoresis. Result revealed presence of 3 (range 15.2-40.3 kDa), 13 (9.3-121.2 kDa), 14 (9.3-169.3 kDa), and 15 (8.0-169.3 kDa) polypeptides in McAg, ImIAg, ImRAg, and AAg, respectively. With an aim to identify a suitable immunodiagnostic antigen for early diagnosis of amphistomosis, the IgG antibody response to various developmental stage antigens in goats experimentally infected with metacercariae of P. epiclitum was evaluated by ELISA. The highest OD values were recorded with ImIAg which ranged between 0.23 and 0.55 with a significant increase from the 2nd week till 8th week of infection with a peak at 6th week. The analysis of statistical significance using a one-way analysis of variance with multiple pair wise comparisons revealed that IgG response was significantly higher with all antigens (P < 0.01) except McAg (P > 0.05) with a maximum mean difference of 0.1838 in comparison to control with ImIAg, thus, indicating that ImIAg which could be further exploited for its potential is a candidate for immunodiagnostic antigen for early diagnosis of amphistomosis.

Immunoaffinity chromatographic analysis for purification of specific diagnostic antigens of Paramphistomum epiclitum

Polypeptide profile of somatic antigen of Paramphistomum epiclitum (PSAg) and Gastrothylax crumenifer (GSAg) was studied by SDS-PAGE. PSAg and GSAg showed 14 and 19 polypeptides in the range of 14.9-95.5 and 13.7-129.6 kDa with six common polypeptides of mol wt 16.8, 21.8, 23.7, 35.5, 43.4 and 70.8 kDa. P. epiclitum experimentally infected sheep sera were used for identification of specific immuno-dominant peptide in the range of 37-40 kDa against P. epiclitum by western blotting. Hyperimmune sera (HIS) was raised in rabbit against the identified polypeptide, IgG was separated from HIS and an immunoaffinity column was constructed with a binding percentage of 83.74 of IgG with CNBr activated Sepharose 4B. Purification of somatic antigen (PSAg) was done with immunoaffinity chromatography and 37-40 kDa protein antigen was isolated in pure form with recovery percentage of 2.97%. This purified fraction of somatic antigen can be used as a candidate antigen for development of serological assay for early diagnosis of paramphistomosis among livestock.

Partial purification and characterization ofGigantocotyle explanatumsomatic antigens

Soluble extracts ofGigantocotyle explanatum, isolated from the liver of buffaloBubalus bubaliswere fractionated on Sephadex G-200 columns. Nine major fractions referred to as F1, F2, F3, F4, F5, F6, F7, F8 and F9 were separated. Each fraction was tested by ELISA for antigenicity using sera fromG. explanatum-infected field buffaloes. Fractions F1 and F2 were highly antigenic, F3, F4, F6 and F7 were moderately antigenic and F5, F8 and F9 were poorly antigenic. Analyses by SDS–PAGE revealed that each fraction comprised several polypeptide(s) in the molecular weight range of <29 to >205 kDa. Results of Western blotting indicated that not all polypeptides which appeared in the SDS–PAGE were antigenic. The antigenic molecules of each fraction were mostly in the low molecular weight range of <14 to >94 kDa with the polypeptides in the range of >14, 14, 18, 21–25 and 34–36 kDa.

Immunology and pathology of intestinal trematodes in their definitive hosts

This review examines the significant literature on the immunology and pathology of intestinal trematodes in their definitive hosts. We emphasize information on selected species in six families for which the literature on these topics is extensive. The families are Brachylaimidae, Diplostomidae, Echinostomatidae, Gymnophallidae, Heterophyidae, and Paramphistomidae. For most of these families, coverage is considered under the following headings: (i) background; (ii) pathology of the infection; (iii) immunology of the infection; (iv) immunodiagnosis; and (v) human infection. Some of these heading have been subdivided further, based on the literature available on a particular topic. Following this coverage, we include a final section on the important topical literature on selected trematodes in families other than the six mentioned above.