The Output of First Stage Larvae by Cats Infested with Aelurostrongylus abstrusus

1968 ◽  
Vol 42 (3-4) ◽  
pp. 295-298 ◽  
Author(s):  
J. M. Hamilton ◽  
A. W. McCaw
Keyword(s):  
Life Cycle ◽  
Great Britain ◽  
Intermediate Host ◽  
World Wide ◽  
Wide Distribution ◽  
Clinical Disease ◽  
Complex Life Cycle ◽  
Patent Period ◽  
Aelurostrongylus Abstrusus

Aelurostrongylus abstrusus, the lungworm of the cat, has a world wide distribution and has been reported from countries as far apart as America, Great Britain and Palestine. It has a complex life cycle insofar as a molluscan intermediate host is essential and it is possible that auxiliary hosts also play an important part. In Britain, the incidence of active infestation of cats with the parasite has been recorded as 19·4% (Lewis, 1927) and 6·6% (Hamilton, 1966) but the latter author found that, generally, the clinical disease produced by the parasite was of a mild nature. It is known that the average patent period of the infestation in the cat is 8–13 weeks and it seems likely that, in that time, a considerable number of first stage larvae would be evacuated. Information on that point is not available and the object of the following experiment was to ascertain the number of larvae produced by cats during the course of a typical infestation.

Nannizzia incurvata. [Descriptions of Fungi and Bacteria].

1965 ◽  
Author(s):  
P. M. Stockdale
Keyword(s):  
Great Britain ◽  
Geographical Distribution ◽  
Guinea Pigs ◽  
Tinea Capitis ◽  
World Wide ◽  
Skin Lesions ◽  
Wide Distribution ◽  
Tinea Corporis ◽  
Soil P ◽  
Infected Skin

Abstract A description is provided for Nannizzia incurvata. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Recorded only from man and dog (but see NOTES). Guinea-pigs have been experimentally infected. DISEASE: Ringworm (dermatophytosis, tinea). Nannizzia incurvata is present in soil and apparently only rarely a cause of disease. In man the scalp (tinea capitis) and glabrous skin (tinea corporis) may be infected. Skin lesions are inflammatory but details of known scalp infections are not available. In experimental inoculations of guineapigs (Rdzanek, pers. comm.) N. incurvata was intermediate between N. gypsea and N. fulva in virulence, the reaction varying from negative to strongly inflammatory. Ectothrix hyphae breaking up into large arthrospores were seen on some hairs, and infected hairs did not fluoresce under Wood's light. GEOGRAPHICAL DISTRIBUTION: Asia (India), Europe (Czechoslovakia, Great Britain and Ireland, Germany, Netherlands, Poland); U.S.A. (Tenn.); N. incurvata is probably of world-wide distribution in the soil.

A comparative study of the life-histories of mammalian schistosomes

Parasitology ◽  
1983 ◽  
Vol 87 (2) ◽  
pp. 343-369 ◽  
Author(s):  
Eric S. Loker
Keyword(s):  
Life Cycle ◽  
Adult Worm ◽  
Intermediate Host ◽  
Definitive Host ◽  
Life Histories ◽  
Egg Production ◽  
Patent Period ◽  
Shell Size ◽  
Progeny Size ◽  
Facultative Parthenogenesis

SUMMARYAvailable data in the literature pertaining to the life-history characteristics of all known species of mammalian schistosomes have been gathered, and correlations between such variables as length of pre-patent period, adult worm size, rate of progeny production and progeny size have been explored. Accommodation of the schistosome life-cycle to the constraints imposed by certain host characteristics such as life-expectancy and size is discussed. Of the 23 known species of mammalian schistosomes, 20 species apparently rely to a major extent on relatively large-bodied and long-lived mammals such as primates, ungulates and proboscideans for their transmission. Only 1 species,Schistosomatium douthitti, is exclusively dependent on rodents for its transmission.S. douthittiattains maturity within its definitive host faster than any other mammalian schistosome, and is the only species known to be capable of producing viable eggs by facultative parthenogenesis. For all species of mammalian schistosomes, adult worm size, as estimated by female length, is positively correlated with the number of uterine eggs contained within the female (r= 0·682). For the 7 species for which data exist, rate of egg production/worm pair/day is positively correlated with uterine egg counts (r= 0·873) and inversely correlated with egg length (r= −0·787) and miracidium length (r= −0·953). Length of the pre-patent period is positively correlated with egg length (r= 0·503). With respect to the molluscan host, the number of cercariae produced by snails is positively correlated with the shell size of the snail (r= 0·657). For the 5 species for which data exist, the rate of egg production is inversely correlated with shell size of the intermediate host (r= −0·955) and the common logarithm of the number of cercariae produced (r= −0·893). Comparisons between species suggest that exceptionally low rates of cercariae production in the intermediate host may be compensated for by rapid rates of egg production in the definitive host, implying a degree of integration in the schistosome life-cycle not previously appreciated. Most species of mammalian schistosomes have long-lived definitive hosts, and snail hosts capable of producing many cercariae; compensatory relationships are therefore less obvious in such species. Additional quantitative data on all aspects of schistosome life-histories, particularly rate and duration of egg production, are needed to confirm or refute the relationships discussed above.

scholarly journals Parasites are Particularly Problematic

2018 ◽  
Vol 2 ◽  
pp. e25604
Author(s):  
Susan Perkins
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Information Content ◽  
Definitive Host ◽  
Complex Life Cycle ◽  
Phylogenetic Study ◽  
Biodiversity Informatics ◽  
Malaria Parasites ◽  
Parasitic Organism

Although they are hyperdiverse and intensively studied, parasites present major challenges when it comes to phylogenetics, taxonomy, and biodiversity informatics. The collection of any parasitic organism entails the linking of at least two specimens - the parasite and the host. If the parasite has a complex life cycle, then this becomes further complicated by requiring the linking of three or more hosts, such as the parasite, its intermediate host (vector) and its definitive host(s). Parasites are sometimes collected as byproduct of another collection event and are not studied immediately - which has the potential to disconnect them further in terms of information content and continuity- and the converse if also common - parasites can be collected by parasitologists, who do not necessarily take host vouchers or incorporate host taxonomy, let alone other metadata for these events. Using the specific example of the malaria parasites (Order Haemosporida) I will present examples of the specific challenges that have accompanied the study of these parasites including issues of delimiting species, phylogenetic study, including genetic oddities that are unique to these organisms, and taxonomic quandries that we now find ourselves in, along with other problems with maintaining continuity of information in a group that is both diverse biologically and important medically.

The Role of the Mouse in the Life Cycle of Aelurostrongylus abstrusus

1967 ◽  
Vol 41 (4) ◽  
pp. 309-312 ◽  
Author(s):  
John M. Hamilton ◽  
A. W. McCaw
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Post Mortem ◽  
Aelurostrongylus Abstrusus

Two experiments were undertaken to assess the role of the mouse in the life-cycle of Aelurostrongyhis abslrusus. In the first, 18 mice were fed first stage larvae and killed one month later. At post-mortem and histopathological examinations larvae were not demonstrated and attempts to extract larvae from a proportion of the mice were also negative. In the second experiment, 24 mice were fed heavy doses of first stage larvae. Subsequent examinations failed to reveal the presence of larvae and post-mortem and histopathological examinations performed on two cats, each of which had been fed with six of the mice, failed to reveal the presence of lungworms. It is concluded that mice do not act as intermediate host for Aelurostrongyhis abstrusus.

An acanthocephalan parasite boosts the escape performance of its intermediate host facing non-host predators

Parasitology ◽  
2008 ◽  
Vol 135 (8) ◽  
pp. 977-984 ◽  
Author(s):  
V. MEDOC ◽  
J.-N. BEISEL
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Definitive Host ◽  
Complex Life Cycle ◽  
Escape Performance ◽  
Intermediate Hosts ◽  
Host Condition ◽  
Gammarus Roeseli ◽  
The Cost ◽  
Acanthocephalan Parasite

SUMMARYAmong the potential effects of parasitism on host condition, the ‘increased host abilities’ hypothesis is a counterintuitive pattern which might be predicted in complex-life-cycle parasites. In the case of trophic transmission, a parasite increasing its intermediate host's performance facing non-host predators improves its probability of transmission to an adequate, definitive host. In the present study, we investigated the cost of infection with the acanthocephalanPolymorphus minutuson the locomotor/escape performance of its intermediate host, the crustaceanGammarus roeseli. This parasite alters the behaviour of its intermediate host making it more vulnerable to predation by avian definitive hosts. We assessed the swimming speeds of gammarids using a stressful treatment and their escape abilities under predation pressure. Despite the encystment ofP. minutusin the abdomen of its intermediate host, infected amphipods had significantly higher swimming speeds than uninfected ones (increases of up to 35%). Furthermore, when interacting with the non-host crustacean predatorDikerogammarus villosus, the highest escape speeds and greatest distances covered by invertebrates were observed for parasitized animals. The altered behaviour observed among the manipulated invertebrates supported the ‘increased host abilities’ hypothesis, which has until now remained untested experimentally. The tactic of increasing the ability of infected intermediate hosts to evade potential predation attempts by non-host species is discussed.

The Fowl (Gallus domesticus) and a lepidopteran (Setomorpha rutella) as experimental hosts for Tetrameres mohtedai (Nematoda)

Parasitology ◽  
1975 ◽  
Vol 70 (1) ◽  
pp. 143-148 ◽  
Author(s):  
C. W. Lim
Keyword(s):  
Life Cycle ◽  
Experimental Evidence ◽  
Intermediate Host ◽  
Final Host ◽  
Gallus Domesticus ◽  
Infective Stage ◽  
Patent Period ◽  
Infective Larvae ◽  
Laboratory Conditions ◽  
Infected Adult

The life-cycle of Tetrameres mohtedai in the fowl involving a hitherto unknown intermediate host, Setomorpha rutella, is described and methods for laboratory demonstration are given. Development to infectivity in the intermediate host took less than 2 weeks under laboratory conditions. Infections could be established using infective larvae dissected from the intermediate host. The pre-patent period in the fowl averaged 36 days. Experimental evidence is given for infection of the final host by ingestion of either infected adult or infected larval Setomorpha. Development of the parasite to the infective stage does not depend on metamorphosis of the intermediate host.

scholarly journals Major host transitions are modulated through transcriptome-wide reprograming events in Schistocephalus solidus, a threespine stickleback parasite

2016 ◽  
Author(s):  
François Olivier Hébert ◽  
Stephan Grambauer ◽  
Iain Barber ◽  
Christian R Landry ◽  
Nadia Aubin-Horth
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Final Host ◽  
Life Cycles ◽  
Threespine Stickleback ◽  
Complex Life Cycle ◽  
Ecological Niches ◽  
Avian Host ◽  
Complex Life Cycles ◽  
Schistocephalus Solidus

ABSTRACTParasites with complex life cycles have developed numerous phenotypic strategies, closely associated with developmental events, to enable the exploitation of different ecological niches and facilitate transmission between hosts. How these environmental shifts are regulated from a metabolic and physiological standpoint, however, still remain to be fully elucidated. We examined the transcriptomic response of Schistocephalus solidus, a trophically-transmitted parasite with a complex life cycle, over the course of its development in an intermediate host, the threespine stickleback, and the final avian host. Results from our differential gene expression analysis show major reprogramming events among developmental stages. The final host stage is characterized by a strong activation of reproductive pathways and redox homeostasis. The attainment of infectivity in the fish intermediate host – which precedes sexual maturation in the final host and is associated with host behaviour changes – is marked by transcription of genes involved in neural pathways and sensory perception. Our results suggest that un-annotated and S. solidus-specific genes could play a determinant role in host-parasite molecular interactions required to complete the parasite’s life cycle. Our results permit future comparative analyses to help disentangle species-specific patterns of infection from conserved mechanisms, ultimately leading to a better understanding of the molecular control and evolution of complex life cycles.

On the Occurrence of Ostertagia pinnata Daubney, 1933, in Association with Ostertagia trifurcata Ransom, 1907 in India and Great Britain

1954 ◽  
Vol 28 (3-4) ◽  
pp. 151-154 ◽  
Author(s):  
M. M. Sarwar
Keyword(s):  
United States ◽  
New Zealand ◽  
Great Britain ◽  
World Wide ◽  
Wide Distribution ◽  
London School ◽  
Sheep And Goats ◽  
Predominant Species ◽  
First Time ◽  
Different Parts

Ostertagia trifurcata was first described by Ransom (1907) from sheep and goats in United States. It has since been reported from various other countries and appears to have a world wide distribution. This species is recorded from India for the first time, in the present paper.In Great Britain, O. trifurcata was first recorded by Boulenger (1914) but his record seems to have been overlooked by Travassos (1987). It has also been reported from sheep and goats in different parts of Great Britain by Morgan (1925), Jones (1926) and Oldham and Morgan (1984). All these workers report the occurrence of this species in association with Ostertagia circumcincta. Elsewhere, the association of O. circumcincta and O. trifurcata has been reported by Tetley (1984) from New Zealand, Ransom (1911) from United States, Gebauer (1982) from Germany and Saquenet (1946) from Algeria. In my collection from India (Kangra District), O. trifurcata,is present in small numbers together with O. circumcincta which is always the predominant species. In a collection of helminths from Cyprus in the London School of Hygiene and Tropical Medicine a few O. trifurcata were found in association with a large number of O. circumcincta.

scholarly journals Developing a dedicated cestode life cycle database: lessons from the hymenolepidids

2009 ◽  
Vol 46 (1) ◽  
pp. 21-27 ◽  
Author(s):  
F. Lefebvre ◽  
B. Georgiev ◽  
R. Bray ◽  
D. Littlewood
Keyword(s):  
Life Cycle ◽  
Open Access ◽  
Intermediate Host ◽  
Life Cycles ◽  
Complex Life Cycle ◽  
Short Version ◽  
Electronic Database ◽  
Model Group ◽  
Future Needs

AbstractThe Cestode Life Cycle Database (CLCdb) project was initiated in 2005 with the objective to develop a comprehensive and centralised resource to store, retrieve and analyse key information concerning tapeworm life cycles; e.g. morphogenesis, intermediate host identities, transmission patterns, etc. It constitutes the first electronic database to deal with complex life cycle information for any helminth taxon. Here we critically evaluate our experience after exhaustively entering data for our model group, the cyclophyllidean family Hymenolepididae. After providing basic statistics (530 consulted references; ∼ 230 ‘known’ life cycle), we identify future needs in turning the CLCdb into an open access monograph covering all cestode groups. We review the added benefits and potential utilities of the database for cestodologists and other users, including ecologists and veterinarians, and we call for specialist contributions. Since late 2007, a short version of the CLCdb has been available online, with basic functionalities and tools (www.nhm.ac.uk/research-curation/projects/cestode-life-cycle/index.html).

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