The furcocercus cercariae of Neodiplostomum seoulense (Digenea: Neodiplostomidae) penetrate the skins of tadpoles and shed their tails. The speculated mechanism of this tail loss was physical efforts required to produce a vigorous zigzag motion during skin penetration; no other mechanism has been proposed. We examined the relationship between the host serum and cercarial tail loss. Cercariae of N. seoulense were collected from experimentally infected Segmentina hemisphaerula, and lots of 300 cercariae were cultured in medium 199 contained several types of sera. Cercarial tail degradation was induced in all media, but all the cercariae cultured except those cultured in media containing fetal bovine serum (FBS) died within 48 hr. After 72 hr cultivation in media containing FBS, cercarial tail degradation was induced in 67.0%; in continuous cultivation 13.3% of larvae survived for 7 days. Tail degradation did not occur in the absence of serum and when serum was heat inactivated at 56 degrees C for 30 min. The addition of 20 mM ethylenediaminetetraacetic acid (EDTA) blocked cercarial tail degradation completely. Moreover, the addition of 20 mM MgCl2 restored tail degradation blocked by EDTA. These results suggest that the alternative complement pathway is related with the N. seoulense cercarial tail degradation induced by serum.
Trematoda/*physiology ; Tail/*physiology ; Larva/parasitology ; Complement System Proteins/immunology/*physiology ; Anura/parasitology ; Animals

OBJECTIVETo detect the species of larval trematodes (cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine.

METHODSA total of 1 880 Melanopsis praemorsa snails were collected from different fresh water bodies in Palestine from October, 2008 to November, 2010. Cercariae in Melanopsis praemorsa snails were obtained by lighting and crushing methods. The behavior of cercariae was observed using a dissecting microscope.

RESULTSThree different species of larval trematodes were identified from Melanopsis praemorsa snails collected only from Al-Bathan fresh water body, while snails from other water bodies were not infected. These species were microcercous cercaria, xiphidiocercaria and brevifurcate lophocercous cercaria. These cercariae called Cercaria melanopsi palestinia I, Cercaria melanopsi palestinia II and Cercaria melanopsi palestinia III have not been described before from this snail in Palestine. The infection rate of Melanopsis praemorsa collected from Al-Bathan fresh water body was 5.7%, while the overall infection rate of snails collected from all fresh water bodies was 4.3%. Details are presented on the morphology and behavior of the cercariae as well as their development within the snail.

CONCLUSIONSThese results have been recorded for the first time and these cercariae may be of medical and veterinary importance.

Animals ; Cercaria ; Fresh Water ; Host-Parasite Interactions ; Larva ; Snails ; parasitology ; Trematoda ; physiology

Adult worms of Parvatrema spp. (Digenea: Gymnophallidae) were found in the intestines of 2 species of migratory birds, i.e., a great knot, Calidris tenuirostris, and 2 Mongolian plovers, Charadrius mongolus, in the coastal area of Gunsan-si, Jeollabuk-do in October 2009. The recovered Parvatrema worms were 79 in total number and composed of 2 species. The worms from a great knot were 289 micrometer in length with the oral and ventral sucker ratio of 2 : 1. They had a single vitellarium, and their intrauterine eggs were 25.0 x 17.5 micrometer in size. These findings were compatible with P. duboisi (Dollfus, 1923) Bartoli, 1974 (syn. P. timondavidi Bartoli, 1963). The worms recovered from the Mongolian plovers were smaller in length than P. duboisi and had 2 vitellaria. The oral and ventral sucker ratio was 2.5 : 1, and the eggs were 17.5 x 8.8 micrometer in size. These worms were assigned to be P. homoeotecnum James, 1964. This is the first report on the natural final hosts of Parvatrema spp. in Korea.
*Animal Migration ; Animals ; Bird Diseases/*parasitology ; Charadriiformes/*parasitology/physiology ; Trematoda/anatomy & histology/*isolation & purification ; Trematode Infections/parasitology/*veterinary

Serine proteases form one of the most important families of enzymes and perform significant functions in a broad range of biological processes, such as intra- and extracellular protein metabolism, digestion, blood coagulation, regulation of development, and fertilization. A number of serine proteases have been identified in parasitic helminths that have putative roles in parasite development and nutrition, host tissues and cell invasion, anticoagulation, and immune evasion. In this review, we described the serine proteases that have been identified in parasitic helminths, including nematodes (Trichinella spiralis, T. pseudospiralis, Trichuris muris, Anisakis simplex, Ascaris suum, Onchocerca volvulus, O. lienalis, Brugia malayi, Ancylostoma caninum, and Steinernema carpocapsae), cestodes (Spirometra mansoni, Echinococcus granulosus, and Schistocephalus solidus), and trematodes (Fasciola hepatica, F. gigantica, and Schistosoma mansoni). Moreover, the possible biological functions of these serine proteases in the endogenous biological phenomena of these parasites and in the host-parasite interaction were also discussed.
Animals ; Cestoda/classification/*enzymology/growth & development/physiology ; Host-Parasite Interactions ; Life Cycle Stages ; Nematoda/classification/*enzymology/growth & development/physiology ; Serine Proteases/genetics/*metabolism ; Trematoda/classification/*enzymology/growth & development/physiology

Stray cats are a common feature roaming the streets and alleys of Kuwait; they could be a source of parasites, including trematodes, that affect humans. A survey was conducted to identify feline trematodes and throw the light on their public health significance in Kuwait. Out of 240 stray cats trapped from different localities of Kuwait from June 2011 to May 2012, 59 (24.6%) were found to be infected with 14 species of trematodes. The most common were trematodes of the genus Heterophyes, particularly H. heterophyes and H. dispar that were found in respectively 15.8% and 10.8% of the cats examined. Other trematodes recorded, with lower prevalences, were Heterophyes nocens (2.9%), Haplorchis taichui (3.8%), Stictodora sawakinensis (2.1%), Stellantchasmus falcatus (1.6%), Echinochasmus japonicus (1.6%), and Mesostephanus dottrensi (1.3%). Centrocestus cuspidatus, Galactosomum fregatae, Ascocotyle sp., Mesostephanus appendiculatus, Haplorchis yokogawai, and Pygidiopsis genata showed the lowest prevalence (0.4%) and intensity. The majority of the trematodes are recorded for the first time in Kuwait and even in the Gulf region. The study reveals that stray cats are good indicators of fish-borne trematodes in the environment. As all trematodes recovered are zoonotic, their significance to public health should be considred.
Animals ; Cat Diseases/epidemiology/*parasitology/transmission ; Cats ; Female ; Fish Diseases/epidemiology/parasitology ; Fishes ; Kuwait/epidemiology ; Male ; Trematoda/classification/genetics/*isolation & purification/physiology ; Trematode Infections/epidemiology/parasitology/*veterinary ; Zoonoses/epidemiology/*parasitology

The developmental features, growth and organogenesis of Macroorchis spinulosus were observed in albino rats. Globular and thick walled metacercariae, possessed a stylet, Y-shaped excretory bladder and extracecal testes. In albino rats, M. spinulosus showed habitat shifting. The majority of M. spinulosus reside in the jejunum for the first four days post infection (p.i.) and migrate to the duodenum at the later stage of infection. M. spinulosus grew rapidly during the first four days and reached full maturity at 14 days p.i. and later reduced in size. The ovary was separated from the genital primodium at one day p.i. The seminal vesicle appeared on the third day and divided into two sacs on the fourth day p.i. and intrauterine eggs and sperm mass were produced on the fourth day. Organogenesis and enlargement of reproductive organs governed the growth of M. spinulosus. The similarity of related species of the genus Macroorchis to M. spinulosus was discussed in consideration to developmental features.
Animals ; Astacoidea/parasitology ; Female ; Male ; Organogenesis ; Ovary/growth & development ; Pharynx/growth & development ; Rats ; Rats, Sprague-Dawley ; Seminal Vesicles/growth & development ; Testis/growth & development ; Trematoda/anatomy & histology/*growth & development/physiology

Metacercariae of Gynaecotyla squatarolae (Digenea: Microphallidae) were discovered from the shore crab, Macrophthalmus dilatatus, purchased at a market in a coastal town of Taean-Eup, Chungcheongnam-do, Republic of Korea. Their adult flukes were confirmed by experimental infection of rats. The metacercariae of G. squatarolae were elliptical (391.1 x 362.5 micrometer), and the excysted metacercariae had progenetic genital organs, including the ovary and testes. To obtain adult flukes, 6 Sprague-Dawley rats were fed 500 metacercariae each, and killed at days 2, 4, and 6 post-infection. The adult flukes were identified as G. squatarolae (Yamaguti, 1934) Yamaguti, 1939, based on morphological characters, including 2 ventral suckers (1 large and 1 small), a large genital atrium equipped with the cirrus and the metraterm, separated male and female genital pores, a transversely long cirrus pouch, and extensive vitelline follicles. In the present study, it has been first proven that the shore crab M. dilatatus is a second intermediate host for G. squatarolae in the Republic of Korea.
Animals ; Brachyura/*parasitology ; Female ; Host-Parasite Interactions ; Korea ; Life Cycle Stages/physiology ; Male ; Rats ; Rats, Sprague-Dawley ; Time Factors ; Trematoda/*anatomy & histology/isolation & purification/*pathogenicity ; Trematode Infections/parasitology/*veterinary

Neodiplostomum seoulense (Digenea: Neodiplostomidae) is an intestinal trematode that can cause severe mucosal pathology in the small intestines of mice and even mortality of the infected mice within 28 days after infection. We observed neuronal growth associated protein-43 (GAP-43) expression in the myenteric plexus of the small intestinal wall of N. seoulense-infected mice until day 35 post-infection (PI). BALB/c mice were infected with 200 or 500 N. seoulense metacercariae isolated from naturally infected snakes and were killed every 7 days for immunohistochemical demonstration of GAP-43 in the small intestines. N. seoulense-infected mice showed remarkable dilatation of intestinal loops compared with control mice through days 7-28 PI. Conversely, GAP-43 expression in the mucosal myenteric plexus was markedly (P<0.05) reduced in the small intestines of N. seoulense-infected mice during days 7-28 PI and was slightly normalized at day 35 PI. From this study, it is evident that neuronal damage occurs in the intestinal mucosa of N. seoulense-infected mice. However, the correlation between intestinal pathology, including the loop dilatation, and depressed GAP-43 expression remains to be elucidated.
Animals ; *Down-Regulation ; Female ; GAP-43 Protein/*genetics/metabolism ; Humans ; Intestine, Small/*metabolism/parasitology ; Male ; Metacercariae/growth & development/isolation & purification ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C3H ; Trematoda/growth & development/isolation & purification/*physiology ; Trematode Infections/*genetics/metabolism/parasitology