Immunodiagnosis of paramphistomosis using monoclonal antibody-based sandwich ELISA for detection of Paramphistomum gracile circulating 16 kDa antigen

Tegumental surface change in Paramphistomum epiclitum caused by Bombax ceiba flowers and black pepper seed extract

Rumen flukes, parasites of the superfamily Paramphistomoidea, are found in cattle rumen. Heavy infections can cause symptoms such as diarrhea, weight loss, and poor body condition, resulting in a decrease in milk and meat production. This study compares the tegumental surface change of Paramphistomum epiclitum as a response to ethanolic extracts of Bombax ceiba flowers and black pepper seeds. Adult flukes were subjected to various concentrations of crude extracts, including 12.5, 25, 50, 100, and 200 μg/mL for 12, 18, and 24 h incubation. Scanning electron microscopy (SEM) exhibited that the ethanolic extracts of both Bombax ceiba flowers and black pepper seeds caused tegumental surface changes in adult P. epiclitum. Based on the results, Bombax ceiba flower extract has anthelmintic activity, compared with black pepper seed extract, towards adult P. epiclitum due to the deformation of the tegument at lower concentrations than black pepper extract.

Multi-detection for paramphistomes using novel manually designed PAR-LAMP primers and its application in a lateral flow dipstick (LAMP-LFD) system

Loop-mediated isothermal amplification (LAMP) has been applied for the detection of various parasites, and its application in lateral flow dipstick (LFD) can improve the convenience of point-of-care diagnosis. A novel PAR-LAMP probe and primers were designed by manual selection from a region of low variation in the ITS-2 DNA sequence. Up to six species of rumen fluke were detected by LAMP and LAMP-LFD in this study. Target specificity and sensitivity were tested, revealing a high target specificity (accuracy) and a low limit of detection (sensitivity). Different target sensitivities of paramphistome were presented, including 5 pg for Gastrothylax crumenifer and Carmyerius sp.; 1 pg for Fischoederius elongatus, Orthocoelium parvipapillatum, and O. dicranocoelium; and 0.1 pg for Paramphistomum epiclitum. LAMP-LFD can detect a paramphistome egg even in contaminated in feces that was spiked with the egg under laboratory conditions. In addition, natural paramphistome infection in cattle from Surat Thani and Khon Kaen provinces, Thailand, was evaluated by detection of egg contamination in fecal specimens using PAR-LAMP primers. The PAR-LAMP detection result was also statistically evaluated by microscopic examination of feces. This study presents the application of novel manually designed primers in a LAMP-LFD system for improving performance in detection and diagnosis assays for paramphistomosis.

Rumen Fluke in Cattle and Buffaloes in Asia: A Review

Rumen fluke is a parasitosis that infects ruminant animals across a wide geographical range of countries. It is a severe infection in temperate and tropical climate regions of Asia, Australia, Africa, and Europe, which cause significant economic losses. In this review, the available information to date on rumen fluke species infecting cattle and buffaloes in Asian countries is evaluated. The citation search was performed through specific keywords, literature published from 1964 to 2021, retrieved from electronic databases: Scopus, Web of Science, Pub Med, Education Resources Information Center (ERIC), Science Direct, Elsevier, and Google Scholar. Twenty-six (26) rumen fluke species belonging to two families: Paramphistomidae 61.5% (16/26) and Gastrothylacidae 38.4% (10/26), were reported in cattle and buffaloes in fourteen Asian countries. Paramphistomum cervi and Cotylophoron cotylophorum are the most prevalent species with broader distribution in countries than the other genera. The coprological prevalence varies from 0.8% to 98.17% and 0.86% to 78.4% in cattle and buffaloes, respectively. The prevalence of rumen fluke by fluke counts method range between 6.45% to 90.6% and 4.29% to 75.07% in cattle and buffaloes, respectively. The sedimentation method and fluke count are reliable tests for detecting rumen fluke in live and slaughtered animals. In conclusion, the rumen fluke should be considered a critical production disease that affects cattle and buffaloes in Asia. Further studies are necessary to determine the rumen fluke-snail associations, develop diagnostic tests to detect prepatent infections in the definitive host, determine the economic importance of rumen fluke, and determine the efficacy of different anthelmintic in the treatment of patent infections in the definitive host.

Molecular and recombinant characterization of major surface protein 5 from Anaplasma marginale

Anaplasmosis is a tick-borne disease caused by the intracellular rickettsia Anaplasma marginale, which affects cattle and other ruminants in both tropical and subtropical regions of the world, and also causing tremendous economic losses due to decreasing livestock production. The major surface protein 5 (MSP5) of A. marginale is an immunodominant and highly conserved protein encoding by a single gene. In the present study, the complete full-length of the msp5 coding sequence of A. marginale Thailand strain was cloned and determined at a size of 633 bp. Phylogenetic analysis based on neigh-joining (NJ) method showed that the msp5 sequence Thailand strains were clearly distributed in 3^rd clade and conserved when compared with other strains. The results showed 9 haplotypes of the msp5 genes, and the entropy analysis of MSP5 amino acid sequences displayed 92 high entropy peaks with value ranging from 0.198 to 0.845 Additionally, a recombinant MSP5 of A. marginale (rAmMSP5) was over-expressed in the E. coli BL21 Star™ (DE3) host cell, affinity purified, and found in SDS-PAGE at a molecular weight of 26 kDa. The antigenicity of rAmMSP5 (26 kDa) and AmMSP5 (19 kDa) was recognized by rabbit anti-rAmMSP5 antisera and A. marginale-infected cattle sera. Both rAmMSP5 and AmMSP5 were perceived by these sera manifesting that recombinant and native AmMSP5 have conserved epitopes. Immunofluorescence technique using rabbit anti-rAmMSP5 antisera exhibited that the AmMSP5 is distributed on both the membrane and the outside of infected erythrocytes. Therefore, the recombinant MSP5 could be used for the development of immunodiagnostic assays and vaccine purposes for controlling anaplasmosis.

The anthelmintic potentials of medicinal plant extracts and an isolated compound (rutin, C27H30O16) from Terminalia catappa L. against Gastrothylax crumenifer

Paramphistomosis is a pathogenic disease that occurs frequently in tropical and subtropical countries including Thailand. This disease is affected in the parasites causing severe gastrointestinal disorders and death in infected animals. In the present study, we examined the anthelmintic efficacy of albendazole (ABZ) and crude plant extracts from barks of Bombax ceiba L., Diospyros rhodocalyx Kurz. and Vitex glabrata R.Br., and leaves of Terminalia catappa L. and Cassia alata L. against Gastrothylax crumenifer. The hightest anthelmintic activity on the parasites after 24 h incubation was observed in the n-butanol extract of T. catappa leaf. In this study, fractionation bioassay of n-butanol extract of T. catappa leaf was conducted to both separation and discrimination of rutin served as a new efficient compound (LC₅₀ = 28.96; LC₉₀ = 88.75 μg/mL) against G. crumenifer. This compound was confirmed by ¹H nuclear magnetic resonance (¹H NMR), ¹³C NMR, infrared (IR) and ultraviolet (UV) spectra as well as mass spectra data. The rutin-treated parasites with all dosages showed swift decrease of the motility and the relative motility (RM) and survival index (SI) were decreased obviously from 3 h until flukes were killed after 12 h of incubation. When observed with light microscopy, the parasites showed the earliest change in a limited region of the tegument. When observed by scanning electron microscopy, the parasites' tegument exhibited similar sequences of surface changes after treatments with rutin and ABZ, but less severity in ABZ treatment. The sequences of changes comprised swelling of folds and ridges, formation of blebbing, rupturing of blebs, erosions, lesions and the tegument demolition. Hence, rutin could be considered as the potential anthelmintic agent for treatment of paramphistomosis.

Fenobody and RANbody-based sandwich enzyme-linked immunosorbent assay to detect Newcastle disease virus

BACKGROUND

Traditional sandwich enzyme-linked immunosorbent assay (ELISA) using polyclonal and monoclonal antibodies as reagents presents several drawbacks, including limited amounts, difficulty in permanent storage, and required use of a secondary antibody. Nanobodies can be easily expressed with different systems and fused with several tags in their tertiary structure by recombinant technology, thus offering an effective detection method for diagnostic purposes. Recently, the fenobody (ferritin-fused nanobody) and RANbody (nanobody-fused reporter) have been designed and derived from the nanobody for developing the diagnostic immunoassays. However, there was no report about developing the sandwich ELISA using the fenobody and RANbody as pairing reagents.

RESULTS

A platform for developing a sandwich ELISA utilizing fenobody as the capture antibody and RANbody as the detection antibody was firstly designed in the study. Newcastle disease virus (NDV) was selected as the antigen, from which 13 NDV-specific nanobodies were screened from an immunized Bactrian camel. Then, 5 nanobodies were selected to produce fenobodies and RANbodies. The best pairing of fenobodies (NDV-fenobody-4, 800 ng/well) and RANbodies (NDV-RANbody-49, 1:10) was determined to develop the sandwich ELISA for detecting NDV. The detection limits of the assay were determined to be 2² of hemagglutination (HA) titers and 10 ng of purified NDV particles. Compared with two commercial assays, the developed assay shows higher sensitivity and specificity. Meanwhile, it exhibits 98.7% agreement with the HA test and can detect the reference NDV strains belonging to Class II but not Class I.

CONCLUSIONS

In the presented study, the 13 anti-NDV nanobodies binding the NDV particles were first produced. Then, for the first time, the sandwich ELISA to detect the NDV in the different samples has been developed using the fenobody and RANbody as reagents derived from the nanobodies. Considering the rapidly increasing generation of nanobodies, the platform can reduce the cost of production for the sandwich ELISA and be universally used to develop assays for detecting other antigens.

Recombinant expression and characterization of major surface protein 4 from Anaplasma marginale

Anaplasma marginale is the rickettsia which causes the bovine anaplasmosis. The distribution of A. marginale is both tropical and subtropical regions of the world. The major surface protein 4 (MSP4) of this parasite was identified as an immunodominant protein. In this study, the full length of DNA encoding A. marginale MSP4 (AmMSP4) was cloned from the parasites. The open reading frame of msp4 coding sequence of Thailand strain is 849 bp. Phylogenetic analysis revealed that the msp4 coding sequence of A. marginale was highly conserved when compared with Anaplasma phagocytophilum. The recombinant plasmid was further transformed into the BL21-CodonPlus (DE3)-RIPL competent cells for over-expression of the recombinant major surface protein 4 of A. marginale (rAmMSP4). Sera from rabbit immunized with rAmMSP4 and from cattle infected with A. marginale were used to study the antigenicity of rAmMSP4 (35 kDa) and AmMSP4 (31 kDa). Both rAmMSP4 and AmMSP4 were recognized by these sera showing that recombinant and native AmMSP4 have conserved epitopes. Localization of Anaplasma parasites by immunofluorescence showed these parasites are distributed on both the membrane and the outside of infected erythrocytes. Regarding antigenicity, recombinant MSP4 could be used for immunodiagnostic purposes and as a possible vaccine candidate against anaplasmosis.

The in vitro anthelmintic activity of the ethanol leaf extracts of Terminalia catappa L. on Fasciola gigantica

At present, there are no medicinal plant extracts currently available for treatment and control of fasciolosis. The present work could provide, for the first study, conclusions on the in vitro fasciolicidal properties of the ethanol extract of Terminalia catappa L. (TcCE) leaves against adult Fasciola gigantica after incubation with RPMI-1640 medium containing the TcCE at various concentrations and times when compared with triclabendazole (TCZ). The relative motility and survival index values of the TcCE-treated flukes decreased at a more rapid rate than the TCZ-treated flukes. The death of the parasites was observed after exposed to TcCE at 3 h incubation with 400, 800 and 1000 µg mL−1, and at 6 h incubation in 100 and 200 µg mL−1. Vacuolization, blebbings and partial disruption on the parasites’ tegument were observed by light microscopy. When examined by scanning electron microscopy, TcCE caused similar tegumental alterations in the parasites as those observed in TCZ treatment but with larger damage at comparative incubation periods, consisting of swelling, blebbing, disrupted blebs, loss of spines, leading to the erosion, lesion and eventual disruption of the total tegument. Therefore, the TcCE may exert its fasciolicidal effect against F. gigantica by initially causing the tegumental alteration.

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.