• Parasites, Hosts and Diseases
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• 제44권3호
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• pp.187-196
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• 2006

The mammalian trematode Paragonimus westermani is a typical digenetic parasite, which can cause paragonimiasis in humans. Host tissues and blood cells are important sources of nutrients for development, growth and reproduction of P. westermani. In this study, a cDNA clone encoding a 47 kDa hemoglobinase of P. westermani was characterized by sequencing analysis, and its localization was investigated immunohistochemically. The phylogenetic tree prepared based on the hemoglobinase gene showed high homology with hemoglobinases of Fasciola hepatica and Schistosoma spp. Moreover, recombinant P. westermani hemoglobinase degradaded human hemoglobin at acidic pH (from 3.0 to 5.5) and its activity was almost completely inhibited by E-64, a cysteine proteinase inhibitor. Immunohistochemical studies showed that P. westermani hemoglobinase was localized in the epithelium of the adult worm intestine implying that the protein has a specific function. These observations suggest that hemoglobinase may act as a digestive enzyme for acquisition of nutrients from host hemoglobin. Further investigations may provide insights into hemoglobin catabolism in P. westermani.

• 대한수의학회지
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• 제14권1호
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• pp.59-71
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• 1974

The studies were conducted on the allergic skin reaction of bovine eurytremiasis. In order to confirm the appearance of allergic skin reaction in this disease, a protein fraction of Eurytrema SPP(EPF) was extracted, and it's antigenicity was studied by means of intradermal reaction on the rabbits, goats and bovine. Rabbits used in this studies were divided into three groups: the first group was sensitized with EPF, the second group was sensitized with EPF, and the third group was served as control which is consisted with 5 non-sensitized and 2 saline injected rabbits. Three healthy native goats and bovine also used. Among these, 86 cases were eurytremiasis, 31 cases were fascioliasis and 71 cases non-infected. A protein fraction was also made from adult worm of Fasciola SPP(FPF) and tested the cross reaction between these two different fluke infestations. The results obtained were as follow: 1. Intradermal reaction was appeared in the infected cattle(bovine eurytremiasis) as well as in the EPF sensitized rabbits and goats. 2. In the EPF sensitized rabbits, the wheal of the intradermal reaction reacted the maximum size (increased wheal size of 5.0 to 9.0 mm) in 40 to 60 minutes and erythema in 60 minutes after intradermal injection of EPF antigen. In the EPF sensitized goats, the size of wheal reacted the maximum(increased wheal size of 5.5 to 8.0 mm) in 30 to 40 minutes, and then disappeared in 120 to 180 minutes after injection of EPF antgen. On the contrary, in the control groups of rabbits and goats, the wheal (7.0 mm) produced following antigen injection reached only to 7.5 to 8.5 mm. in 10 minutes without developing erythema, and then perished in 40 to 60 minutes after injection of EPF antigen. In the infected cattle, the wheal of the intradermal reaction reached the maximal sizes(increased wheal size of 4.0 to 11.0 mm) in 15 to 20 minutes and perished in 60 to 90 minutes after injection of EPF antigen. 3. It would be standardized that the positive reaction is above 4.0 mm, the negative below 2.0 mm and the suspective is 3.0 mm of the infected cattle. In the results of intradermal reaction, 87.2%(75 of 86 cases) was positive, 4.7%(4 of 86 cases) negative and 8.1% (7 of 86 cases) was suspective. However, in the non-infected control cattle, the wheal produced following injection disappeared in 30 to 40 minutes without increasing the wheal size in the most subjects or with incresing only to 1.0 to 2.0 mm in a few cattle. 4. In the results of intradermal reaction which were reciprocally tested in EPF sensitized rabbits by FPF antigen and in FPF sensitized. rabbits by EPF antigen, there were cross reacted. In the 31 cases if fascioliasis tested by EPF antigen, 11 cases were not specifically reacted with EPF antigen. Judging from the results of cross reaction in experimental rabbits and natural bovine fascioliasis, it would be expected when both EPF and EPF antigens are given intracutaneously on the same bovine patients of eurytremiasis or fascioliasis, the former antigen will produce the larger wheal in eurytremiasis, while the latter antigen will produce also the larger wheal in fascioliasis.