The Role of Tadpoles and Frogs as Paratenic Hosts in the Life Cycle of Dracunculus insignis (Nematoda: Dracunculoidea)

1995 ◽  
Vol 81 (5) ◽  
pp. 792 ◽  
Author(s):  
Mark L. Eberhard ◽  
Floy H. Brandt
Keyword(s):  
2019 ◽  
Vol 98 (8) ◽  
pp. 897-902 ◽  
Author(s):  
Viktoria V. Erofeeva ◽  
O. V. Maslennikova

Introduction. Morbidity toxocariasis, second in prevalence geohelminthiasis in Russia, is a serious problem in recent years, especially in metropolitan areas. The involvement of earthworms in the life cycle of toxocarias remains poorly understood. The role of earthworms (paratenic hosts) in the circulation and prevention of toxocariasis is established. The work is aimed at a contribution finding out of earthworms Еisеniа fеtidа (paratenic hosts) in toxocariasis circulation and prevention. Material and methods. Nematodes dehelminthization derived from animals. For the first time in Russian Federation, experiments have been conducted on infestation of earthworms Е. fеtidа with infective eggs Tоxоcаrа cаnis and Tоxоcаrа mystax. Results. In the conducted experiments, possibility is proved of infestation of earthworms Е. fеtidа with infective eggs Т. canis and Т. mystax via earth bacterized with 10000 infective eggs. For the first time migration was proved of ascaridate larvae from intestines to skin-muscular sac of the earthworms. Conclusion. Besides, investigation was conducted aimed at finding out of the period duration of Т. canis and Т. mystax larvae staying in earthworms’ intestines and sinews.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marialetizia Palomba ◽  
Simonetta Mattiucci ◽  
Fabio Crocetta ◽  
David Osca ◽  
Mario Santoro

AbstractAscaridoid nematodes comprise a wide range of heteroxenous parasites infecting top fish predators and marine mammals as definitive hosts, with crustaceans, squids, and fishes acting as intermediate/paratenic hosts. Limited data exist on the species and role of several intermediate and paratenic hosts in the life cycle of these parasites. In the aim of adding knowledge on the role of squid species in their life cycle, we have here investigated the larval ascaridoid nematodes collected from the deep-sea umbrella squid Histioteuthis bonnelli and the reverse jewel squid Histioteuthis reversa captured in the Central Mediterranean Sea (Tyrrhenian Sea). Morphological study and sequence analysis of the internal transcribed spacer (ITS) regions of the ribosomal DNA (rDNA) and the mitochondrial cytochrome c oxidase subunit 2 (mtDNA cox2) gene locus revealed the occurrence of Anisakis physeteris and of an unidentified species of the genus Lappetascaris. Sequence analysis revealed that specimens of Lappetascaris from both squid species matched at 100% sequences previously deposited in GenBank from larval ascaridoids collected in octopuses of the genus Eledone of the Mediterranean Sea. The Bayesian inference tree topology obtained from the analysis of the fragments amplified showed that Lappetascaris specimens were included in a major clade comprising Hysterothylacium species collected in fishes of the families Xiphiidae and Istiophoridae. As regards the site of infection in the squid host species, A. physeteris larvae predominated (60.7%) in the gonads, while those of Lappetascaris (76.3%) were found infecting the mantle musculature. The overall high values of parasitic load suggest both squid species as transmitting hosts of third stage larvae of Lappetascaris to top predator fishes, as well as the umbrella squid as an intermediate/paratenic host in the life cycle of A. physeteris in the Mediterranean Sea.


2013 ◽  
Vol 26 (2 (special Issue)) ◽  
pp. 269-274
Author(s):  
Abdul- Hussain H. Awad ◽  
Iltifat A. A. Al-Tameemi

Author(s):  
Petar Halachev ◽  
Victoria Radeva ◽  
Albena Nikiforova ◽  
Miglena Veneva

This report is dedicated to the role of the web site as an important tool for presenting business on the Internet. Classification of site types has been made in terms of their application in the business and the types of structures in their construction. The Models of the Life Cycle for designing business websites are analyzed and are outlined their strengths and weaknesses. The stages in the design, construction, commissioning, and maintenance of a business website are distinguished and the activities and requirements of each stage are specified.


2021 ◽  
Vol 22 (9) ◽  
pp. 4438
Author(s):  
Jessica Proulx ◽  
Kathleen Borgmann ◽  
In-Woo Park

The ubiquitin (Ub) proteasome system (UPS) plays a pivotal role in regulation of numerous cellular processes, including innate and adaptive immune responses that are essential for restriction of the virus life cycle in the infected cells. Deubiquitination by the deubiquitinating enzyme, deubiquitinase (DUB), is a reversible molecular process to remove Ub or Ub chains from the target proteins. Deubiquitination is an integral strategy within the UPS in regulating survival and proliferation of the infecting virus and the virus-invaded cells. Many viruses in the infected cells are reported to encode viral DUB, and these vial DUBs actively disrupt cellular Ub-dependent processes to suppress host antiviral immune response, enhancing virus replication and thus proliferation. This review surveys the types of DUBs encoded by different viruses and their molecular processes for how the infecting viruses take advantage of the DUB system to evade the host immune response and expedite their replication.


2021 ◽  
Vol 22 (2) ◽  
pp. 643
Author(s):  
Xiao Li ◽  
Fen Wang ◽  
Yanyan Xu ◽  
Guijun Liu ◽  
Caihong Dong

Hydrophobins are a family of small secreted proteins found exclusively in fungi, and they play various roles in the life cycle. In the present study, genome wide analysis and transcript profiling of the hydrophobin family in Cordyceps militaris, a well-known edible and medicinal mushroom, were studied. The distribution of hydrophobins in ascomycetes with different lifestyles showed that pathogenic fungi had significantly more hydrophobins than saprotrophic fungi, and class II members accounted for the majority. Phylogenetic analysis of hydrophobin proteins from the species of Cordyceps s.l. indicated that there was more variability among the class II members than class I. Only a few hydrophobin-encoding genes evolved by duplication in Cordyceps s.l., which was inconsistent with the important role of gene duplication in basidiomycetes. Different transcript patterns of four hydrophobin-encoding genes during the life cycle indicated the possible different functions for each. The transcripts of Cmhyd2, 3 and 4 can respond to light and were related with the photoreceptors. CmQHYD, with four hydrophobin II domains, was first found in C. militaris, and multi-domain hydrophobins were only distributed in the species of Cordycipitaceae and Clavicipitaceae. These results could be helpful for further function research of hydrophobins and could provide valuable information for the evolution of hydrophobins.


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