Antigenic components, isolation and partial characterization of excretion-secretion fraction of Paramphistomum cervi

The Anthelmintic Effects of Medicinal Plant Extracts Against Paramphistome Parasites, Carmyerius spatiosus

INTRODUCTION

Paramphistomosis is a disease caused by the rumen flukes which cause an acute gastroenteritis and anemia with high mortality particularly in young ruminants.

MATERIALS AND METHODS

In this study, we have investigated the anthelmintic effect of medicinal plant extracts from leaves and heartwoods of Cassia siamea L., roots of Plumbago zeylanica L. and Plumbago indica L., and leaves of Terminalia catappa L. against Carmyerius spatiosus.

RESULTS

The highest anthelminthic effect on the flukes after 24 h of exposure was found in heartwood ethyl acetate extract of C. siamea (LC₅₀ = 374.30; LC₉₀ = 749.03 ppm), root n-butanol extract of P. zeylanica (LC₅₀ = 1005.12; LC₉₀ = 2411.55 ppm), root hexane, ethyl acetate, and n-butanol extract of P. indica (LC₅₀ = 34.38, 211.34, 506.92; LC₉₀ = 64.09, 496.05, 934.86 ppm), and leaf n-butanol and water extract of T. catappa (LC₅₀ = 487.17, 470.28; LC₉₀ = 913.27, 848.23 ppm). When observed by scanning electron microscopy, the tegument showed similar sequence of morphological changes after treatments with all plant extracts, comprising of swelling of ridges and folds, blebbing, rupturing of the blebs, erosion, lesion and disruption of the tegument.

CONCLUSION

This study is the first report on the anthelmintic activity of plant extracts to C. spatiosus; therefore, these plant extracts are highly effective in the elimination of adult rumen flukes.

Diagnostic potential of low molecular weight excretory secretory proteins of Paramphistomum epiclitum for caprine amphistomosis

In the present study, the 75% alcoholic fractionation of excretory-secretory (ES) antigen isolated from 200 to 300 live P. epiclitum was assessed for its diagnostic potential for the detection of caprine amphistomosis by using antibody detection enzyme immunoassay. Prior to enzyme immunoassay, 75% alcoholic fractionation of excretory-secretory (ES) antigen was subjected to SDS- PAGE and western blot analysis for the presence of immunoreactive polypeptides. SDS-PAGE analysis of ES antigen resolved a total 7 polypeptides bands of size 56, 27, 25, 22.5, 12, 11 and 10 kDa. Western blot analysis revealed only two immunoreactive polypeptides (11 kDa and 12 kDa) when polypeptides resolved in SDS-PAGE were probed with known positive pooled serum. None of the polypeptides showed reactions with pooled known negative serum. The working dilutions of antigen, sera and conjugates were determined by checkerboard titration for employing ELISA and cut-off O.D. was calculated 0.616 by using the mean absorbance value of 11 negative kid sera. The sensitivity and specificity of ELISA was found to be 100% and 86.76%, respectively. As per kappa value estimation, the strength of agreement was found to be good. Antibodies to 75% alcoholic fractionation of ES antigen was detected in 20% goats (n = 160) of either sex, although faecal examination detected 10.6% goats to be infected with amphistomosis. The study confirmed that 75% alcoholic fractionation of ES antigen of P. epiclitum based ELISA had good value for serodiagnosis of caprine amphistomosis.

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.

Paramphistomosis of Ruminants: An Emerging Parasitic Disease in Europe

Whilst historically regarded as being of minor importance in European livestock, recent evidence suggests that the prevalence of paramphistomosis is greater than that of fasciolosis in parts of the UK. In order to address this emerging threat to ruminant farming systems, and associated risks for food security posed by rumen fluke infection, it is imperative that we develop a better understanding of the basic biology of this parasite and how it interacts with its ruminant host. In this Opinion article we review recent progress in tracking the spread of rumen fluke infection in Europe, and propose some research questions that should be addressed if we are to develop tools to diagnose and treat paramphistomosis more effectively in the future.

Standardization of dot-enzyme-linked immmunosorbent assay for the diagnosis of bovine visceral schistosomiasis

Aim:

Bovine visceral schistosomiasis has been reported as an important disease entity as it affects animal health, productivity, causes economic losses due to liver condemnation, and produces a high morbidity. This study was conducted to standardize an easy, reliable dot-enzyme-linked immmunosorbent assay (ELISA) for the diagnosis of visceral schistosomiasis caused by Schistosoma spindale and to know the prevalence rate in and around Hyderabad.

Materials and Methods:

A dot-ELISA was standardized in the laboratory using whole worm antigen (WWA) and excretory-secretory antigen (ESA) of S. spindale. The standardized test was used for the diagnosis of bovine visceral schistosomiasis at field level. The sensitivity and specificity of the test was compared with counter current immunoelectrophoresis. In total, 288 sera (125 cattle and 163 buffalo) were screened by dot-ELISA.

Results:

The dot-ELISA detected 32.63% of infection (94/288) using WWA and 40.62% of infection (117/288) using ESA. In cattle, the prevalence rate was 32.80% (41/125) using WWA and 40.80% (51/125) of infection. Similarly, in buffaloes, the prevalence rate was 32.51% (53/163) using WWA and 40.49% (66/163) of infection using ESA. The overall sensitivity of dot-ELISA was 76.74% and 80.48% with WWA and ESA, respectively, and specificity was 73.3% and 78.57% in WWA and ESA, respectively.

Conclusion:

As ante-mortem diagnosis of visceral schistosomiasis is difficult in subclinical conditions, dot-ELISA can be used as a reliable immunodiagnostic test for diagnosis at field level.

Immunodiagnosis of paramphistomosis using monoclonal antibody-based sandwich ELISA for detection ofParamphistomum gracilecirculating 16 kDa antigen

In this study, we have produced a monoclonal antibody (MoAb) against 16 kDa antigen ofParamphistomum gracile(16 kDaAgPg), and developed an accurate sandwich enzyme-linked immunosorbent assay (sandwich ELISA) for the detection of circulating 16 kDaAg in the serum and fecal samples from cattle naturally infected withP. gracile. MoAb 1D10 was immobilized on a microtitre plate, and the antigen in the samples was captured and detected with biotinylated rabbit anti-16 kDaAgPg antibody. The lower detection limit of sandwich ELISA was 3·5 pg mL−1, and no cross-reaction with other parasite antigens was evaluated. The reliability of the assay was examined using the serum and fecal samples from cattle naturally infected withP. gracile, Fasciola gigantica, Moniezia benedeni, Trichurissp.,Strongyloidessp., strongylids and non-infected animals. The sandwich ELISA showed the sensitivity, specificity and accuracy at 98·33, 100 and 99·55% (serum samples), and 96·67, 100 and 99·09% (fecal samples). Therefore, this detection method is a rapid and excellent potential assay for the accurate diagnosis of paramphistomosis.

Immunodiagnostic monoclonal antibody-based sandwich ELISA of fasciolosis by detection ofFasciola giganticacirculating fatty acid binding protein

Up to now, parasitological diagnosis of fasciolosis is often unreliable and possesses low sensitivity. Hence, the detection of circulating parasite antigens is thought to be a better alternative for diagnosis of fasciolosis, as it reflects the real parasite burden. In the present study, a monoclonal antibody (MoAb) against recombinantFasciola giganticafatty acid binding protein (rFgFABP) has been produced. As well, a reliable sandwich enzyme-linked immunosorbent assay (sandwich ELISA) has been developed for the detection of circulating FABP in the sera of mice experimentally and cattle naturally infected withF. gigantica. MoAb 3A3 and biotinylated rabbit anti-recombinant FABP antibody were selected due to their high reactivities and specificities. The lower detection limit of sandwich ELISA was 5 pg mL−1, and no cross-reaction with other parasite antigens was observed. This assay could detectF. giganticainfection from day 1 post infection. In experimental mice, the sensitivity, specificity and accuracy of this assay were 93·3, 100 and 98·2%, while in natural cattle they were 96·7, 100 and 99·1%. Hence, this sandwich ELISA method showed high efficiencies and precisions for diagnosis of fasciolosis byF. gigantica.

The anthelmintic effects of the ethanol extract ofTerminalia catappaL. leaves against the ruminant gut parasite,Fischoederius cobboldi

Presently, no effective anthelmintic drugs have been used to treat and control paramphistomosis, a severe disease of ruminants. In this study, we have investigated thein vitroanthelmintic effect of the leaves ofTerminalia catappaL. crude extract (TcCE) and albendazole (ABZ) on adultFischoederius cobboldiafter incubating the flukes in RPMI-1640 medium containing the TcCE at various doses and times. The TcCE-treated flukes at all dosages exhibited rapid decrease of motility, and the relative motility (RM) values were decreased sharply from start to 3 h. Worms were killed after 6 and 12 h of treatment with 1000, 1500 and 2000µg mL−1as well as 500µg mL−1of TcCE, respectively. By light microscopy examination, the flukes exhibited the earliest alteration in a limited area of the tegument. At scanning electron microscopy level, the flukes’ tegument showed similar sequence of morphological alterations after treatment with ABZ and TcCE that consisted of swelling of ridges and folds, followed by blebbing and rupturing of the blebs, leading to the erosion, lesion and disruption of the tegument. Hence,in vivostudies should be performed to examine whether the TcCE may serve as a powerful anthelmintic drug for treatment of paramphistomosis.

Pathological changes in cattle naturally infected by Calicophoron daubneyi adult flukes

Local host response and parasite distribution were studied in the forestomachs, abomasum, duodenum and regional lymph nodes of cattle suffering from bovine paramphistomosis. The parasites were found attached, by its ventral sucker, to small conical papillae of the rumen and reticulum. Affected papillae, showed morphological changes denoted by very narrow stalks and expanded heads. Histologically, these changes were characterized by epithelial acanthosis-hyperkeratosis of the epithelium. Infiltration of inflammatory cells was often related with the epithelial changes, although it was also found in the duodenal mucosa and submucosa. These cells were arranged as aggregates or follicles but sparse infiltration of eosinophils, globule leukocytes, mast cells or macrophages was also observed in the lamina propria. Tissue damage and inflammatory reaction were more severe in the ruminal atrium, where the largest number of flukes and affected papillae were observed. In contrast, lesions in the ruminal dorsal sac were absent or mild. Statistical correlation between lesion severity and parasite burden was confirmed.

Surface topography and ultrastructural architecture of the tegument of adult Carmyerius spatiosus Brandes, 1898

Adult Carmyerius spatiosus or stomach fluke has an elongate, cylindrical-shaped, straight to slightly curved body, with conical anterior end and truncated posterior end. The worm measures about 8.7-11.2mm in body length and 2.3-3.0mm in body width across the mid-section. When observed by SEM, the tegumental surface in all part of the body appears highly corrugated with ridges and furrows, and having no spines. The ventral surface has more complex corrugation than those of the dorsal surface. Both anterior and posterior suckers have thick edges covered with transverse folds and appear spineless. The genital pore is located at the anterior part of the body. There are two types of sensory papillae on the surface: type 1 is bulbous in shape with nipple-like tips; type 2 has a similar shape with short cilia on the tip. The dorsal surface exhibits similar surface features, but papillae appear less numerous and are smaller. When observed by TEM, the tegument is divided into four layers. The first layer includes the ridges and furrows which are covered by a trilaminate membrane underlined by a dense lamina and coated externally with the glycocalyx. The second layer of the tegument is a narrow region of cytoplasm that contains high concentrations of ovoid electron lucent tegumental granules (TG1), and disc-shaped electron dense tegumental granules (TG2) as well as lysosomes. TG1 close to the surface invariably exocytose their content into bottoms of the ridges, while some TG2 are fused and have their membrane joined up with the surface membrane. The third layer is the widest middle area of the tegument which contains numerous and evenly distributed mitochondria. Both TG1 and TG2 granules are present but in much fewer number than in the first and second layers. The fourth layer is the innermost zone that rests on and couples with a thick basal lamina. The cytoplasm in this layer is loosely packed and contains numerous infoldings of the basal plasma membrane with closely associated mitochondria. It also contains fairly large numbers of TG1 and TG2 granules which are produced and transported to the tegument by one type of tegumental cells lying in rows underneath the muscular layers.

Production and characterization of a monoclonal antibody against recombinant cathepsin L1 of Fasciola gigantica

Monoclonal antibodies (MoAbs) against a recombinant cathepsin L1 of Fasciola gigantica (rFgCatL1) were produced in vitro by fusion of BALB/c mice spleen cells immunized with rFgCatL1 and mouse myeloma cells. Reactivity and specificity of these MoAbs were evaluated by indirect ELISA and immunoblotting techniques. Seven MoAb clones were selected from the stable hybridoma clones, namely 1E10, 1F5, 3D11, 4B10, 4D3, 4E3 and 5E7. Clones 1E10, 1F5 and 3D11 were IgM, whereas clones 4B10, 4D3, 4E3 and 5E7 were IgG1. All MoAbs had kappa light chain isotypes. All MoAbs reacted with rCatL1 at molecular weight (MW) 30kDa and with the native CatL1 at MW 27kDa in whole body (WB) extracts of metacercariae (Met), newly excysted juveniles (NEJ), 1, 3, 5-week-old juveniles (Ju), adult WB and adult excretory-secretory (ES) fractions, but not with adult tegumental antigens (TA). All of these MoAbs showed no cross-reactions with antigens of other parasites commonly found in ruminants and human, including Paramphistomum cervi, Eurytrema pancreaticum, Gigantocotyle explanatum, Schistosoma spindale, Schistosoma mansoni, Moniezia benedeni, Avitellina centripunctata, Trichuris sp., Haemonchus placei and Setaria labiato-papillosa. Localization of CatL1 in each developmental stages of F. gigantica by immunoperoxidase technique, using these MoAbs as probes, indicated that CatL1 was present at high concentration in the caecal epithelium and caecal lumen of metacercariae, NEJ, 1, 3, 5-week-old juveniles and adult fluke. This finding indicated that CatL1 is a copiously expressed parasite protein that is released into the ES, thus CatL1 and its MoAb could be a good candidate for immunodiagnosis of fasciolosis in ruminant and human.

Efficacy of Dot-ELISA using different antigens in detecting anti-schistosome antibodies among bovines in field conditions

Schistosomosis has been recognised as one of the major parasitic diseases of livestock and human beings. Schistosoma spindale is the major cause of visceral schistosomosis among bovines of Kerala State. Besides pathology in animals, it has been long known that cercariae of S. spindale are a common cause of dermatitis in human beings in Asia. However, detection of this disease based on coprology has underestimated the prevalence of this economically important disease among cattle of the State. An efficient diagnostic tool providing unequivocal evidence of infection in living animals is perhaps, the key to formulate and deliver control measures to the target population. It is also crucial for an enhanced understanding of parasite epidemiology. The utility of excretory-secretory proteins as diagnostic and vaccine candidates for schistosomosis has been a focus of medical research since long. There exists a paucity of information with regard to analysis of ES proteins of S. spindale and their incorporation to develop sensitive and specific serodiagnostic tool. Hence a study was designed to evaluate the efficacy of Dot-ELISA incorporating different antigens of S. spindale and to validate the test under field conditions.

Morphology and histology of the adult Paramphistomum gracile Fischoeder, 1901

In the present study, we evaluated the histological morphology of the adult Paramphistomum (P.) gracile. Adult flukes with bodies 5~15 mm in length and 2~7 mm in width were subjected to histological analysis. Longitudinal and transversal serial-sections were stained with hematoxylin and eosin, and examined. The body surface and longitudinal section of P. gracile were also assessed using scanning electron microscopy. In this species, the anterior sucker and posterior sucker (acetabulum) were present on an anterior and posterior part of the body, respectively. The major folds were located in the areas of the anterior sucker, genital canal, and posterior sucker. The fluke membrane was spineless at the tegument surface and in the tegument tissue. Histological data showed structural-systematic characteristics of the digestive tract, reproductive tract, excretory tract, copulatory organs, connective tissues, and muscle tissues. We attempted to elucidate the histological characteristics of P. gracile that might increase the knowledge and understanding of rumen fluke morphology.