scholarly journals An experimental field approach to parasitism and immune defence in voles

Parasitology ◽  
2004 ◽  
Vol 129 (1) ◽  
pp. 93-99 ◽  
Author(s):  
G. A. SCHWARZENBACH ◽  
D. HEGGLIN ◽  
C. STIEGER ◽  
P. DEPLAZES ◽  
P. I. WARD
Keyword(s):  
Immune System ◽  
Intermediate Host ◽  
Host Species ◽  
Immune Defence ◽  
Infection Rates ◽  
Intermediate Hosts ◽  
Red Foxes ◽  
Field Approach ◽  
Faecal Samples ◽  
In The Wild

The fox tapewormEchinococcus multilocularisis typically perpetuated in a cycle with red foxes as definitive hosts and various rodent species as intermediate hosts. In this study, foxes were baited with a highly efficient drug against cestodes (praziquantel) in 5 blocks of 1 km2. Voles,Arvicola terrestris, the most abundant intermediate host species, were trapped in the 5 baited blocks and in 5 non-baited control blocks. Baiting the foxes reduced the prevalence ofE. multilocularisin fox faecal samples in the baited blocks, but voles trapped in the two blocks did not differ in their infection rates. However, voles from the baited blocks had significantly smaller spleen masses and were more likely to be infested with mites than those from the control blocks, possibly reflecting different immunological activities. Our study suggests that the environmental contamination withE. multiloculariseggs, and perhaps those of other tapeworms, influences the immune system of the intermediate host speciesA. terrestrisin the wild.

The influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum

1999 ◽  
Vol 73 (2) ◽  
pp. 143-145 ◽  
Author(s):  
A.M. McCarthy
Keyword(s):  
Intermediate Host ◽  
Definitive Host ◽  
Host Species ◽  
Post Infection ◽  
Rana Temporaria ◽  
Biomphalaria Glabrata ◽  
Reproductive Status ◽  
Intermediate Hosts ◽  
Potential Influence ◽  
Second Intermediate Host

The potential influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum to the definitive host Anas platyrhynchos was examined experimentally. Echinoparyphium recurvatum metacercarial cysts were obtained from the following experimentally infected second intermediate hosts 14 days post expsoure to cercariae: Lymnaea peregra; Physa fontinalis; L. stagnalis;Planorbis planorbis; Biomphalaria glabrata; tadpoles of the amphibian Rana temporaria. Metacercarial cysts from each of these hosts were fed, in doses of 50 cysts per individual, to separate groups composed of between four and eight, 3-day-old A. platyrhynchos ducklings. All A. platyrhynchos were necropsied 15 days post-infection and the number, size, and reproductive status of E. recurvatum worms in the intestine was recorded. Analyses of variance on the number (transformed log (x + 1)) and size of worms revealed no significant differences in worms originating from metacercariae formed in the different second intermediate hosts (worm number P > 0.05, and worm size P > 0.05). All worms recovered were found to be gravid. It is therefore concluded that the species of second intermediate host utilized does not influence the infectivity of the metacercarial cyst of E. recurvatum, nor the subsequent establishment and reproductive status of the parasite in A. platyrhynchos.

Observations on the suitability and importance of the domestic intermediate hosts of Echinococcus granulosus in Uttah Pradesh, India

1989 ◽  
Vol 63 (1) ◽  
pp. 39-45 ◽  
Author(s):  
M. Irshadullah ◽  
W. A. Nizami ◽  
C. N. L. Macpherson
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Echinococcus Granulosus ◽  
Frequency Distribution ◽  
Host Species ◽  
Control Measures ◽  
The Other ◽  
Hydatid Cysts ◽  
Intermediate Hosts ◽  
Cyst Size

ABSTRACTThe present study investigated the suitability and importance of buffaloes, camels, sheep, goats and pigs in maintaining the life-cycle of Echinococcus granulosus in Aligarh, India. A total of 565 (36%) of 1556 buffaloes, 20 (2%) of 1208 goats, 5 (1%) of 559 pigs, 6 (6%) of 109 sheep and two of three camels were found to harbour hydatid cysts. The frequency distribution of the hydatid cysts in each intermediate host species was over-dispersed and in buffaloes cyst fertility increased with increasing cyst size. Of 2171, 95 and four buffalo, goat, and camel cysts examined 327 (15%), two (2%) and three cysts respectively were fertile. No pig or sheep cysts were found to contain protoscoleces. The unfenced buffalo abattoir and the large number of dogs allowed access to the abattoir coupled to the number of buffaloes slaughtered in comparison to the other potential hosts, indicates that the buffalo is the most significant host for maintaining the life-cycle of the parasite in this area of India. Applicable control measures for the region are suggested.

Temporal variation of Meiogymnophallus minutus infections in the first and second intermediate host

2010 ◽  
Vol 84 (4) ◽  
pp. 362-368 ◽  
Author(s):  
J. Fermer ◽  
S.C. Culloty ◽  
T.C. Kelly ◽  
R.M. O'Riordan
Keyword(s):  
Temporal Variation ◽  
Intermediate Host ◽  
Seasonal Patterns ◽  
Intertidal Flat ◽  
Infection Rates ◽  
Intermediate Hosts ◽  
Cerastoderma Edule ◽  
Scrobicularia Plana ◽  
Second Intermediate Host ◽  
First Intermediate Host

AbstractIn order to study seasonal patterns of Meiogymnophallus minutus infections in its intermediate hosts, bivalve samples were collected monthly between April 2008 and March 2009 from a high intertidal flat at Courtmacsherry Bay, Ireland. Infection rates in the first intermediate host Scrobicularia plana did not fluctuate significantly with season. Completely developed M. minutus cercariae appeared in daughter sporocysts from June and prevailed from July to October, indicating that transmission of M. minutus from its first to its second intermediate host is confined to this period of the year. All analysed individuals of the second intermediate host Cerastoderma edule were found to be infected with metacercariae. Infection levels significantly increased in September, suggesting recent cercarial invasions. Throughout the year, the majority of metacercariae were hyperinfected by the pathogenic microsporidian Unikaryon legeri. Spreading of hyperinfections was confined to spring and summer. Newly settled metacercariae were not affected by hyperparasitism and presumably retained their infectivity for half a year. Our findings suggest that the spreading of hyperinfections is correlated with higher water temperatures and that the entire metacercarial population has to rebuild every year as a consequence of hyperparasite-induced mortality.

Effect of acanthocephalan parasites on hiding behaviour in two species of shore crabs

2002 ◽  
Vol 76 (4) ◽  
pp. 323-326 ◽  
Author(s):  
A.D.M. Latham ◽  
R. Poulin
Keyword(s):  
New Zealand ◽  
Intermediate Host ◽  
Host Species ◽  
Intermediate Hosts ◽  
Risk Of Predation ◽  
Shore Crabs

AbstractThe effect of acanthocephalan parasites (profilicollis spp.) on the hiding behaviour during low tide of two species of shore crabs (intermediate hosts), Macrophthalmus hirtipes (Brachyura: Ocypodidae) and Hemigrapsus crenulatus (Brachyura: Grapsidae), was examined at Blueskin Bay, South Island, New Zealand. Exposed M. hirtipes were found to have significantly higher infection levels than did hidden conspecifics. This pattern was not observed for H. crenulatus. Mean cystacanth numbers were found to be considerably higher in M. hirtipes than H. crenulatus. Crabs exposed at low tide are at a greater risk of predation by definitive shorebird hosts than are hidden conspecifics. Preferential manipulation of one intermediate host species over another could influence diversity within ecosystems.

scholarly journals Food web structure selects for parasite host range

2019 ◽  
Vol 286 (1908) ◽  
pp. 20191277 ◽  
Author(s):  
A. W. Park
Keyword(s):  
Food Web ◽  
Intermediate Host ◽  
Host Range ◽  
Definitive Host ◽  
Host Species ◽  
Diet Breadth ◽  
Intermediate Hosts ◽  
Food Web Structure ◽  
Web Structure ◽  
The Cost

Complex life cycle parasites, including helminths, use intermediate hosts for development and definitive hosts for reproduction, with interactions between the two host types governed by food web structure. I study how a parasite's intermediate host range is controlled by the diet breadth of definitive host species and the cost of parasite generalism, a putative fitness cost that assumes host range trades off against fitness derived from a host species. In spite of such costs, a benefit to generalism may occur when the definitive host exhibits a large diet breadth, enhancing transmission of generalist parasites via consumption of a broad array of infected intermediate hosts. I develop a simple theoretical model to demonstrate how different host range infection strategies are differentially selected for across a gradient of definitive host diet breadth according to the cost of generalism. I then use a parasitic helminth–host database in conjunction with a food web database to show that diet breadth of definitive hosts promotes generalist infection strategies at the intermediate host level, indicating relatively low costs of parasite generalism among helminths.

Epidemiology of alveolar echinococcosis in southern Cantal, Auvergne region, France

2004 ◽  
Vol 78 (3) ◽  
pp. 237-242 ◽  
Author(s):  
J.-F. Magnaval ◽  
C. Boucher ◽  
B. Morassin ◽  
F. Raoul ◽  
F. Raoul ◽  
...  
Keyword(s):  
Alveolar Echinococcosis ◽  
Epidemiological Survey ◽  
Human Case ◽  
Low Grade ◽  
Elisa Assay ◽  
Intermediate Hosts ◽  
Red Foxes ◽  
Human Volunteers ◽  
Faecal Samples ◽  
Positive Results

AbstractAlveolar echinococcosis (AE) is a helminth zoonosis which is encountered only in the northern hemisphere. In central France, the Auvergne region represents the most western and southern extension of this helminthiasis. In 1999, a human case of AE was diagnosed in the southern part of the Cantal department, where AE was supposed absent, and an epidemiological survey was subsequently carried out. The transmission of the zoonosis in the sylvatic and peridomestic definitive hosts was studied, as well as that in the rodent and human intermediate hosts. Eleven red foxes (Vulpes vulpes) were shot, and 50 fox faecal deposits were collected. Twelve farm dogs had their faeces taken by rectal touch, and four were checked after arecoline purgation. Optical detection ofEchinococcus multilocularisworms was achieved on fox intestines after scraping, and also on dog stools after arecoline therapy. Coproantigen ELISA assay was performed for the 11 scraping products, for the 50 fox faeces, and for the 12 dog faecal samples. No adult AE agent was observed by microscopy, and the ELISA assay yielded positive results in one of 11 fox intestines, one of 50 fox faeces, and 2 of 12 dog faecal samples. Twenty-five small mammals were trapped, of which 19 wereArvicola terrestriswater voles. One rodent liver exhibited a hepatic lesion consistent with AE. An epidemiological questionnaire was completed in 85 human volunteers, who were also serologically tested for AE. Only one (the case's husband) exhibited a Western-blotting pattern indicative of a low-grade AE infection. The results of this preliminary study suggested a slow AE extension to the south of Cantal department from the northern focus.

scholarly journals Parasite-induced colour alteration of intermediate hosts increases ingestion by suitable final host species

Behaviour ◽  
2019 ◽  
Vol 156 (13-14) ◽  
pp. 1329-1348
Author(s):  
Timo Thünken ◽  
Sebastian A. Baldauf ◽  
Nicole Bersau ◽  
Joachim G. Frommen ◽  
Theo C.M. Bakker
Keyword(s):  
Intermediate Host ◽  
Host Species ◽  
Final Host ◽  
Life Cycles ◽  
Intermediate Hosts ◽  
Dead End ◽  
Body Colouration ◽  
Species Specific ◽  
Acanthocephalan Parasite ◽  
Parasitic Manipulation

Abstract Parasites with complex life cycles often alter the phenotypic appearance of their intermediate hosts in order to facilitate ingestion by the final host. However, such manipulation can be costly as it might increase ingestion by less suitable or dead-end hosts as well. Species-specific parasitic manipulation is a way to enhance the transmission to suitable final hosts. Here, we experimentally show that the altered body colouration of the intermediate host Gammarus pulex caused by its acanthocephalan parasite Pomphorhynchus laevis differently affects predation by different fish species (barbel, perch, ruffe, brown trout and two populations of three-spined stickleback) depending on their suitability to act as final host. Species that were responsive to colour manipulation in a predation experiment were more susceptible to infection with P. laevis than unresponsive species. Furthermore, three-spined stickleback from different populations responded to parasite manipulation in opposite directions. Such increased ingestion of the intermediate host by preferred and suitable hosts suggests fine-tuned adaptive parasitic manipulation and sheds light on the ongoing evolutionary arms race between hosts and manipulative parasites.

APPLICATION OF SHIFTING ASSAY OF STANDARDIZED INDIRECT AGGLUTINATION (SSIA) FOR DETECTION OF ANTIGENS OF NEWCASTLE DISEASE AND INFECTIOUS BURSAL DISEASE VIRUSES IN CHICKEN FAECES

2013 ◽  
Vol 83 (5) ◽  
Author(s):  
Phạm Hồng Sơn ◽  
Phạm Hồng Kỳ ◽  
Nguyễn Thị Lan Hương ◽  
Phạm Thị Hồng Hà
Keyword(s):  
Newcastle Disease ◽  
Winter Season ◽  
Summer Season ◽  
Infectious Bursal Disease ◽  
Infection Rates ◽  
Faecal Samples ◽  
Infectious Bursal Disease Viruses ◽  
Bursal Disease ◽  
Long Time ◽  
Higher Sensitivity

. Using the method of shifting assay of standardized indirect agglutination (SSIA), the prevalence of Newcastle disease viruses (NDV) and infectious bursal disease viruses (IBDV) in chickens reared in several districts of Thua Thien Hue province in the Spring-Summer and Fall-Winter seasons was determined. In the Spring-Summer season of 2011, about 22.3% of the chickens were infected with NDV, in which A Luoi  accounted for the highest percentage of 25% of the infected chickens and Huong Thuy  the lowest  of 18.2%. Meanwhile, 36% of the same chickens were infected with IBDV, with the highest percentage (46.66%) also in A Luoi and the lowest (30.3%) also in Huong Thuy. The intensity of NDV infection in the Spring-Summer season in A Luoi and Phu Vang was highest (GMT = 1.45), and in Huong Thuy lowest (GMT = 1.31). In addition, in the Fall-Winter season, about 46% of the chickens were infected with NDV and 46.3% with IBDV in Huong Thuy and Phu Vang – two neighbouring districts of Hue City, in which NDV was detected in 54.4% of the chickens in Huong Thuy and 33.9% in Phu Vang. In contrast, IBDV was detected in 41.9% and 52.7% of the chickens respectively in the two districts. The infection was not inter-dependent. Methodically, although the differences in the infection rates were insignificant with the accuracy of 95%, faecal samples showed higher sensitivity in SSIA analyses for both cases of NDV and IBDV infection in comparision with mouth exudates. By SSIA method, results could be read clearly with unaided eyes for a long time after the performance, and it was also proven applicable for cases of haemagglutinating viruses if proper treatments for depletion of animal RBCs’ surface agglutinins could be applied.

scholarly journals Infectivity of gastropod-shed third-stage larvae of Angiostrongylus vasorum and Crenosoma vulpis to dogs

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
William Robbins ◽  
Gary Conboy ◽  
Spencer Greenwood ◽  
Roland Schaper
Keyword(s):  
Tap Water ◽  
Natural Infection ◽  
Angiostrongylus Vasorum ◽  
Intermediate Hosts ◽  
Red Foxes ◽  
Romaine Lettuce ◽  
Crenosoma Vulpis ◽  
Artificial Digestion ◽  
Third Stage ◽  
Limax Maximus

Abstract Background Metastrongyloid parasites Angiostrongylus vasorum and Crenosoma vulpis infect wild and domestic canids and are important pathogens in dogs. Recent studies indicate that gastropod intermediate hosts infected with various metastrongyloids spontaneously shed infective third-stage larvae (L3) into the environment via feces and mucus under laboratory conditions. Shed L3 retain motility up to 120 days, but whether they retain infectivity was unknown. Methods To assess the infectivity of shed L3, the heart/lungs of six red foxes (Vulpes vulpes) were obtained from trappers in Newfoundland, Canada. Lungs were examined for first-stage larvae (L1) by the Baermann technique. A high number of viable A. vasorum L1 and a low number of C. vulpis L1 were recovered from one fox; these were used to infect naïve laboratory-raised Limax maximus. L3 recovered from slugs by artificial digestion were fed to two naïve purpose-bred research beagles (100 L3/dog). L1 shed by these two dogs was used to infect 546 L. maximus (2000–10,000 L1/slug). L3 shedding was induced by anesthetizing slugs in soda water and transferring them into warm (45 °C) tap water for at least 8 h. Shed L3 recovered from slugs were aliquoted on romaine lettuce in six-well tissue culture plates (80–500 L3/well) and stored at 16 °C/75% relative humidity. Four naïve research beagles were then exposed to 100 L3/dog from larvae stored for 0, 2, 4, or 8 weeks, respectively, after shedding. Results All four dogs began shedding C. vulpis L1 by 26–36 days post-infection (PI). All four dogs began shedding A. vasorum L1 by 50 days PI. Conclusions L3 infectivity for the definitive host was retained in both metastrongyloids, indicating the potential for natural infection in dogs through exposure from environmental contamination. As an additional exposure route, eating or licking plant or other material(s) contaminated with metastrongyloid L3 could dramatically increase the number of dogs at risk of infection from these parasites. Graphic Abstract

scholarly journals Domestication of wild animals may provide a springboard for rapid variation of coronavirus

2021 ◽  
Vol 16 (1) ◽  
pp. 252-254
Author(s):  
Lei Gao
Keyword(s):  
Intermediate Host ◽  
Wild Animals ◽  
Intermediate Hosts ◽  
Natural Conditions ◽  
Rapid Variation ◽  
Cross Breeding ◽  
Important Direction ◽  
Animal Hosts

Abstract Coronaviruses have spread widely among humans and other animals, but not all coronaviruses carried by specific animals can directly infect other kinds of animals. Viruses from most animal hosts need an intermediate host before they can spread widely among humans. Under natural conditions, coronaviruses do not rapidly change from infecting wild animals as intermediate hosts and to spreading widely among humans. The intermediate host might be the animals captured or bred for the purpose of cross-breeding with domesticated species for improvement of the breed. These animals differ from wild animals at the environmental and genetic levels. It is an important direction to study the semi-wild animals domesticated by humans in search for intermediate hosts of viruses widely spread among humans.

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