Achorovermis testisinuosus gen. et sp. n. (Digenea: Aporocotylidae) infects the heart of the smalltooth sawfish, Pristis pectinata Latham (Rhinopristiformes: Pristidae), in the eastern Gulf of Mexico. Specimens of the new genus, along with the other blood flukes that infect batoids are similar by having an inverse U-shaped intestine and a curving testis as well as by lacking tegumental spines. The new genus differs from all of the other blood flukes infecting batoids by having an elongate body (>50 × longer than wide), a testis having >100 curves, and an ovary wholly anterior to the uterus. It differs from Ogawaia glaucostegi Cutmore, Cribb et Yong, 2018, the only other blood fluke infecting a rhinopristiform, by having a body that is >50 × (vs <30 ×) longer than wide, a testis that is >75 × (vs <40 ×) longer than wide and has >100 (vs <70) curves, an ovary wholly anterior to (vs lateral and dorsal to) the seminal vesicle, a uterus wholly posterior to (vs overlapping and lateral to both) the testis and ovary, and a sinuous (vs convoluted) uterus. The new species joins a small group of chondrichthyan blood flukes that lack tegumental spines: O. glaucostegi, Orchispirium heterovitellatum Madhavi et Rao, 1970, Myliobaticola richardheardi Bullard et Jensen, 2008, Electrovermis zappum Warren et Bullard, 2019. Blood flukes infecting batoids are further unique by having a curving testis. That is, the blood flukes infecting species within Selachii are morphologically distinct from those infecting species within the Batoidea (excluding Gymnurahemecus bulbosus Warren et Bullard, 2019). Based on the morphological similarity, we suspect that the new species shares a recent common ancestor with O. glaucostegi. The discovery of the new species brings the total number of chondrichthyan blood flukes to 11 species assigned to nine genera., Micah B. Warren, Micah D. Bakenhaster, Rachel M. Scharer, Gregg R. Poulakis and Stephen A. Bullard., and Obsahuje bibliografii
Here we describe the new trypanosomatid, Phytomonas borealis sp. n., from the midgut of the spiked shieldbugs, Picromerus bidens (Linnaeus), collected in two locations, Novgorod and Pskov Oblasts of Russia. The phylogenetic analyses, based on the 18S rRNA gene, demonstrated that this flagellate is a sister species to the secondary monoxenous Phytomonas nordicus Frolov et Malysheva, 1993, which was concurrently documented in the same host species in Pskov Oblast. Unlike P. nordicus, which can complete its development (including exit to haemolymph and penetration into salivary glands) in Picromerus bidens, the new species did not form any extraintestinal stages in the host. It also did not produce endomastigotes, indispensable for transmission in other Phytomonas spp. These observations, along with the fact that P. bidens overwinters at the egg stage, led us to the conclusion that the examined infections with P. borealis were non-specific. Strikingly, the flagellates from the Novgorod population contained prokaryotic endosymbionts, whereas the parasites from the second locality were endosymbiont-free. This is a first case documenting presence of intracellular symbiotic bacteria in Phytomonas spp. We suggest that this novel endosymbiotic association arose very recently and did not become obligate yet. Further investigation of P. borealis and its intracellular bacteria may shed light on the origin and early evolution of endosymbiosis in trypanosomatids., Anna I. Ganyukova, Alexander O. Frolov, Marina N. Malysheva, Viktoria V. Spodareva, Vyacheslav Yurchenko and Alexei Yu. Kostygov., and Obsahuje bibliografii
Myxobolus pseudodispar Gorbunova, 1936 (Myxozoa) is capable of infecting and developing mature myxospores in several cyprinid species. However, M. pseudodispar isolates from different fish show up to 5% differences in the SSU rDNA sequences. This is an unusually large intraspecific difference for myxozoans and only some of the muscle-dwelling myxozoan species possess such a high genetic variability. We intended to study the correlation between the host specificity and the phylogenetic relationship of the parasite isolates, and to find experimental proof for the putatively wide host range of M. pseudodispar with cross-infection experiments and phylogenetic analyses based on SSU rDNA. The experimental findings distinguished 'primary' and less-susceptible 'secondary' hosts. With some exceptions, M. pseudodispar isolates showed a tendency to cluster according to the fish host on the phylogenetic tree. Experimental and phylogenetic findings suggest the cryptic nature of the species. It is likely that host-shift occurred for M. pseudodispar and the parasite speciation in progress might explain the high genetic diversity among isolates which are morphologically indistinguishable., Barbara Forró, Edit Eszterbauer., and Obsahuje bibliografii
The lung-dwelling nematode Rhabdias engelbrechti sp. n. was found in five of eight examined banded rubber frogs in Limpopo Province, South Africa. The species is differentiated from species of Rhabdias Stiles et Hassall, 1905 occurring in the Afrotropical Realm based on the presence of a globular cuticular inflation at the anterior end, the buccal capsule walls being distinctly divided into anterior and posterior parts, the buccal capsule size (6-9 μm × 16-18 μm), and the body length (3.8-6.1 mm). Rhabdias engelbrechti is the tenth species of the genus found in Afrotropical anurans. Our molecular phylogenetic analysis based on the complete sequences of the ITS region and partial sequences of large subunit (28S) gene of the nuclear ribosomal RNA demonstrates that the new species is more closely related to the Eurasian species Rhabdias bufonis (Schrank, 1788) than to two other species from sub-Saharan Africa represented in the tree. In addition, partial sequences of the mitochondrial protein coding cox1 and ribosomal 12S genes of the new species have shown significant differences from all previously published sequences of these genes from African species of Rhabdias., Yuriy Kuzmin, Ali Halajian, Sareh Tavakol, Wilmien J. Luus-Powell, Vasyl V. Tkach., and Obsahuje bibliografii
Monoclonal antibody specific for an epitope of cretory-secretory antigen protein of Opisthorchis felineus (Rivolta, 1884) (Trematoda: Opisthorchiidae) with a molecular weight of 28 kDa was used in a sandwich enzyme-linked immunosorbent assay (ELISA) for immobilisation of liver fluke specific antigen to the solid phase. Examination of human sera by this ELISA compared with commercial assays demonstrated that the monoclonal antibody epitope is located within this significant parasite protein. Anti-idiotypic antibody specific for the paratope of this monoclonal antibody was obtained by a hybridoma technique. Mimicking an epitope of excretory-secretory antigen of O. felineus, it had the capacity to bind specific antibody and elicit an antibody response. The value of anti-idiotypic antibody as a substitute for the liver fluke antigen was tested by ELISA using serum samples of infected dogs. Anti-idiotypic antibody proved to be of value in both an indirect-ELISA and a competitive-ELISA for diagnosis of opisthorchiasis. Mature trematodes were isolated from all infected animals. The faecal egg counts were negative in dogs with a relatively small number of parasites, despite finding antibodies in serum by ELISA. Substitution of parasite antigen with anti-idiotype avoids the use of experimental animals and also reduces time-consuming steps of antigen preparation., Aitbay K. Bulashev, Sergey N. Borovikov, Shynar S. Serikova, Zhanbolat A. Suranshiev, Vladimir S. Kiyan, Saule Z. Eskendirova., and Obsahuje bibliografii
Tissue samples from wildlife from South Africa were opportunistically collected and screened for haemoprotozoan parasites using nonspecific PCR primers. Samples of 127 individuals were tested, comprising over 50 different species. Haemogregarines were the most commonly identified parasites, but sarcocystids and piroplasmids were also detected. Phylogenetic analyses estimated from the 18S rDNA marker highlighted the occurrence of several novel parasite forms and the detection of parasites in novel hosts. Phylogenetic relationships, which have been recently reviewed, appear to be much more complex than previously considered. Our study highlights the high diversity of parasites circulating in wildlife in this biodiverse region, and the need for further studies to resolve taxonomic issues., D. James Harris, Ali Halajian, Joana L. Santos, Lourens H. Swanepoel, Peter John Taylor, Raquel Xavier., and Obsahuje bibliografii
Faecal samples from the rock hyrax (Procavia capensis jayakari Thomas) were collected from the Ibex Reserve in central Saudi Arabia. Eimerian oocysts, which are believed to represent a new species described here as Eimeria tamimi sp. n., were detected in 40 out of 93 samples. Oocysts were fully sporulated in 24-48 hours at 25 ± 2 °C. Sporulated oocysts of E. tamimi sp. n. were ovoid, measuring 35-42 × 19-25 μm (39 × 23 μm), a length/width ratio 1.5-2 (1.7). Oocyst wall was bilayered and measured 1.5 μm in thickness. Micropyle, oocyst residuum and polar granules were not present. Sporocysts are elongate, measuring 12-18 × 9-12 μm (15 × 10 μm), with a length/width ratio 1.1-1.8 (1.5) prominent Stieda bodies and sporocyst residuum. Experimental infection of two clinically healthy rock hyraxes with sporulated oocysts of E. tamimi sp. n. resulted in shedding unsporulated oocysts 5-10 days post infection. Partial sequences of 18S ribosomal RNA (18S rDNA) and cytochrome C oxidase subunit 1 (COI) regions were amplified using the polymerase chain reaction (PCR) and sequenced. Phylogenetic analysis based on 18S rDNA using maximum likelihood (ML) and Bayesian inference (BI) methods revealed that E. tamimi sp. n. grouped with Eimeria quokka Barker, O'Callaghan et Beveridge, 1988, E. mundayi Barker, O´Callaghan et Beveridge, 1988, E. potoroi Barker, O'Callaghan et Beveridge, 1988 and E. gaimardi Barker, O'Callaghan et Beveridge, 1988 marsupials. Eimerian species have been regarded as a paraphyletic group and the present investigation confirmed the conflict between phenotypic traits, used widely in the classification of this group of parasites., Osama B. Mohammed, Manei M. Aljedaie, M. S. Alyousif and Nabil Amor., and Obsahuje bibliografii
In the parthenogenetic monogeneans of the genus Gyrodactylus Nordmann, 1832, the genetic diversity within or between hosts is determined by the relative roles of lateral transmission and clonal propagation. Clonality and limited transmission lead to high-amplitude metapopulation dynamics and strong genetic drift. In Baltic populations of the three-spined stickleback Gasterosteus aculeatus Linnaeus, the local mitochondrial diversity of Gyrodactylus arcuatus Bychowsky, 1933 is very high, and spatial differentiation weak. To understand the transmission dynamics in a single location, the transmission of the parasite from adults to next generation sticklebacks was investigated in a northern Baltic brackish water location. By sequencing 777 nt of cox1, as many as 38 separate mitochondrial haplotypes were identified. In August, the intensity of gyrodactylid infection on adult hosts was high, the haplotype diversity (h) was extreme and differentiation between fish was negligible (total h = 0.926, mean h = 0.938). In October, only 46% of the juvenile sticklebacks carried G. arcuatus. The number of parasites per young fish followed a Poisson distribution 0.92 ± 1.04 (mean ± SD) on October 2, and was clearly overdispersed 2.38 ± 5.00 on October 25. The total haplotype diversity of parasites on juveniles was nearly as high as in adults (h = 0.916), but the mean per fish was only h = 0.364 (FST = 0.60), due to low intensity of infection and rapid clonal propagation of early arrivals. The initial first come first served advantage of the first gyrodactylid colonisers will be lost during the host adulthood via continuous transmission. Nesting and polygamy are suggested as factors maintaining the high genetic diversity of the parasite population. The transmission dynamics and, consequently, the population structure of Baltic G. arcuatus is fundamentally different from that of G. salaris Malmberg, 1957, on the Baltic salmon Salmo salar Linnaeus., Jaakko Lumme, Marek S. Ziętara., and Obsahuje bibliografii
Parasitic organisms inhabiting the alimentary canal should permanently resist the destructive action of host digestive enzymes. The intestinal parasites were shown to produce specific protease inhibitors protecting them from proteolysis. However, little is known about this adaptive mechanism in cestodes so far, especially for the tapeworms dwelling inside the fish intestines. Here, we explored the ability to inactivate proteolytic enzymes in the fish tapeworm Eubothrium rugosum (Batsch, 1786) (Bothriocephalidea) parasitising the intestine of wild burbot, Lota lota (Linnaeus). The assays were conducted with different concentrations of commercial trypsin and homogenate of intestinal mucosa both being the sources of proteinases. The incubation of live E. rugosum in trypsin solutions of two different concentrations caused a significant decrease in the enzyme activity. The extent of activity reduction was dependent on trypsin concentration. At the same time, the inhibitory effect of the worm incubation medium turned out to be statistically insignificant. These findings suggest partial adsorption of the enzyme to the tegument surface, with its further inactivation. In contrast to the incubation medium, the worm extract suppressed over 80% of trypsin activity and nearly half of the proteolytic activity in the mucosa homogenate. Notably, the inhibitory activity of the tapeworms hardly depended on their size characteristics. Finally, the research has demonstrated secretion of proteinase inhibitor in E. rugosum, which appears to be essential for its survival in enzymatically hostile environment., Galina I. Izvekova, Tatyana V. Frolova, Evgeny I. Izvekov., and Obsahuje bibliografii
Betasyringophiloidus Skoracki, 2011 is a genus of quill mites (Prostigmata: Syringophilidae) that is believed to contain mono-, steno- and polyxenous parasites associated with a wide range of passerine birds (Passeriformes) across the world. In this work we applied the DNA-barcode marker (mitochondrial cytochrome c oxidase subunit I gene fragment, COI) to verify whether Betasyringophiloidus schoeniclus (Skoracki, 2002) and Betasyringophiloidus seiuri (Clark, 1964) are actual steno- and polyxenous species associated with the currently recognised host ranges, or their populations are highly host-specific, cryptic species. Our results revealed that a population living on the Tristram's bunting Emberiza tristrami Swinhoe (Emberizidae) in Russia, so far classified as B. schoeniclus, is a new cryptic species Betasyringophiloidus emberizae sp. nov. Both topologies of the neighbor-joining and maximum likelihood phylogenetic trees as well as genetic distance (11.9% Kimura 2-parameter distance) (K2P) support species status of the mite population from E. tristrami. The same data support previously established conspecific status of B. seiuri found on the ovenbird Seiurus aurocapilla (Linnaeus) (Parulidae) (type host) and the northern waterthrush Parkesia noveboracensis (Gmelin) (Parulidae) and expand its range with a population found on a new host species Icterus pustulatus (Wagler) (Icteridae) with intraspecific K2P distance up to 1.9% and interpopulation distances ranging from 1.3 to 3.1%., Eliza Glowska, Lukasz Broda, Miroslawa Dabert., and Obsahuje bibliografii