To date, only a few species of Hepatozoon Miller, 1908 have been described from amphibians and reptiles of South Africa, including two species from anuran hosts, three from saurians, one from chelonians, and two from ophidians. Hepatozoon bitis (Fantham, 1925) and Hepatozoon refringens (Sambon et Seligmann, 1907), parasitising Bitis arientans (Merrem) and Pseudoaspis cana (Linnaeus), respectively, were described in the early 1900s and since then there have been no further species of Hepatozoon described from snakes in South Africa. Blood smears, used in peripheral blood haemogregarine stage morphometrics, and whole blood used in molecular characterisation of haemogregarines were collected from the caudal vein of six snakes of three species, namely Philothamnus hoplogaster (Günther), Philothamnus semivariegatus (Smith) and Philothamnus natalensis natalensis (Smith). For comparison, a comprehensive table summarising available information on species of Hepatozoon from African snakes is presented. Haemogregarines found infecting the snakes from the present study were morphologically and molecularly different from any previously described from Africa and are thus here described as Hepatozoon angeladaviesae sp. n. and Hepatozoon cecilhoarei sp. n. Both haemogregarine species were observed to cause considerable dehaemoglobinisation of the host cell, in case of infection with H. angeladaviesae resulting in a characteristic peripheral undulation of the host cell membrane and karyorrhexis. To the authors' knowledge, these are the first haemogregarines parasitising snakes of the genus Philothamnus Smith described using both morphological and molecular characteristics in Africa., Courtney Antonia Cook, Edward Charles Netherlands, Johann van As, Nico Jacobus Smit., and Obsahuje bibliografii
Based on light and scanning electron microscopical studies, two new species of parasitic nematodes are described from marine perciform fishes off New Caledonia: Cucullanus epinepheli sp. n. (Cucullanidae) from the intestine of the brownspotted grouper Epinephelus chlorostigma (Valenciennes) (Serranidae) and Procamallanus (Spirocamallanus) sinespinis sp. n. from the intestine of the silver grunt Pomadasys argenteus (Forsskål) (Haemulidae). Cucullanus epinepheli sp. n. differs from its congeners mainly in possessing a unique structure of the anterior, elevated cloacal lip with a large posterior outgrowth covering the cloacal aperture and in the presence of cervical alae and two small preanal papillae on the median dome-shaped precloacal elevation. This is the second known nominal species of this genus parasitising fishes of the family Serranidae and the second representative of Cucullanus Müller, 1777 recorded from fishes in New Caledonian waters. Procamallanus (Spirocamallanus) sinespinis sp. n. is mainly characterised by 10-12 spiral ridges in the buccal capsule, the presence of wide caudal alae, three pairs of pedunculate preanal papillae, two unequally long spicules (465-525 µm and 218-231 µm) and by the tail tip with a knob-like structure in the male, and the broad, rounded tail with a terminal digit-like protrusion without cuticular spikes in the female. This is the fifth nominal species of the subgenus Spirocamallanus Olsen, 1952 reported from fishes in New Caledonian waters., František Moravec, Jean-Lou Justine., and Obsahuje bibliografii
Two new lung-dwelling nematode species of the genus Rhabdias Stiles et Hassall, 1905 were discovered in Caxiuanã National Forest, Pará state, Brazil. Rhabdias galactonoti sp. n. was found in a dendrobatid frog Adelphobates galactonotus (Steindachner). The species is characterised by the regularly folded inner surface of the anterior part of the buccal capsule seen in apical view, flask-shaped oesophageal bulb and narrow, elongated tail. Rhabdias stenocephala sp. n. from two species of leptodactylid frogs, Leptodactylus pentadactylus (Laurenti) (type host) and L. paraensis (Heyer), is characterised by a narrow anterior end that is separated from the remaining body by a constriction. Both species possess six small but distinct lips, a cuticle that is inflated along the whole body, a doliiform buccal capsule separated into a longer anterior and a shallow, ring-shaped posterior part, lateral pores in the body cuticle and zones of spermatogenesis in the syngonia. Rhabdias galactonoti sp. n. is the first species of the genus found in Dendrobatidae; R. stenocephala sp. n. is the second species described from Leptodactylidae in eastern Amazonia., Yuriy Kuzmin, Francisco Tiago de Vasconcelos Melo, Heriberto Figueira da Silva Filho, Jeannie Nascimento dos Santos., and Obsahuje bibliografii
Morphological and molecular analyses of cestode specimens collected during survey work of batoid elasmobranchs and their parasites in Senegal revealed two new species of the rhinebothriidean cestode genus Stillabothrium Healy et Reyda 2016. Stillabothrium allisonae Dedrick et Reyda sp. n. and Stillabothrium charlotteae Iwanyckyj, Dedrick et Reyda sp. n. are both described from Fontitrygon margaritella (Compagno et Roberts) and Fontitrygon margarita (Günther). Both new cestode species overlap in geographic distribution, host use and proglottid morphology, but are distinguished from each other, and from the other seven described species of Stillabothrium, on the basis of their pattern of bothridial loculi. Phylogenetic analyses based on sequence data for 1,084 bp from the D1-D3 region of 28S rDNA that included multiple specimens of both new species and eight other species of Stillabothrium corroborated the morphologically-determined species boundaries. The phylogenetic analyses indicate that S. allisonae sp. n. and S. charlotteae sp. n. are sister species, a noteworthy pattern given that the two species of the stingray genus Fontitrygon they both parasitise, F. margaritella and F. margarita, are also sister species. Although species of Stillabothrium vary widely in their patterns of facial loculi, the variation does not appear to correlate with phylogeny. Most species of Stillabothrium parasitise myliobatiform elasmobranch genera of the Dasyatidae Jordan. This study brings the number of described species of Stillabothrium to nine, three of which occur in the eastern Atlantic, two of which occur off the northern coast of Australia, and four of which are from coastal Borneo., Elsie A. Dedrick, Florian B. Reyda, Elise K. Iwanyckyj, Timothy R. Ruhnke., and Obsahuje bibliografii
In the present study two new species of Tetragonocephalum Shipley et Hornell, 1905, T. mackenziei sp. n. and T. kazemii sp. n., are described from the spiral intestine of the cowtail stingray, Pastinachus sephen (Forsskål), from the northern coast of the Gulf of Oman. Tetragonocephalum mackenziei is distinguished from the 16 other valid species of Tetragonocephalum by a unique combination of characteristics, i.e. sperm-filled seminal receptacle in immature proglottids, body length (7.7-17.5 mm), body width (213-288 µm), number of proglottids (34-49), number of testes (10-14), size of scolex (228-315 µm × 213-288 µm) and size of acetabula (56-73 µm × 61-75 µm). Tetragonocephalum kazemii is morphologically distinguishable from its valid congeners and T. mackenziei based on a combination of characteristics, including body length (28.8-36.6 mm), number of proglottids (50-65), number of testes (30-42), size of scolex (388-564 µm × 326-448 µm), size of acetabula (62-86 µm × 57-90 µm) and testes (25-39 × 21-32). This brings the total number of validly described species of Tetragonocephalum to 18 and expands our knowledge of this diverse genus to now include the Gulf of Oman, as well as Arafura Sea, northern Indian Ocean and western Pacific Ocean., Atabak Roohi Aminjan, Masoumeh Malek., and Obsahuje bibliografii
During investigations of gill ectoparasites (Platyhelminthes) parasitising freshwater fish from Central America (Guatemala, Honduras, El Salvador and Panama) and southeastern Mexico (Guerrero, Oaxaca and Chiapas), the following dactylogyrid monogenoidean were found: Urocleidoides simonae sp. n. from Profundulus punctatus (Günther) (type host), Profundulus balsanus Ahl, Profundulus guatemalensis (Günther), Profundulus kreiseri Matamoros, Shaefer, Hernández et Chakrabarty, Profundulus labialis (Günther), Profundulus oaxacae (Meek), Profundulus sp. 1 and Profundulus sp. 2 (all Profundulidae); Urocleidoides vaginoclaustroides sp. n. from Pseudoxiphophorus bimaculata (Heckel) (type host) and Poeciliopsis retropinna (Regan) (both Poeciliidae); and Urocleidoides vaginoclaustrum Jogunoori, Kritsky et Venkatanarasaiah, 2004 from P. labialis, Profundulus portillorum Matamoros et Shaefer and Xiphophorus hellerii Heckel (Poeciliidae). Urocleidoides simonae sp. n. differs from all other congeneric species in having anchors with well-differentiated roots, curved elongate shaft and short point. Urocleidoides vaginoclaustroides sp. n. most closely resembles U. vaginoclaustrum, but differs from this species mainly in the shape of its anchors (i.e. evenly curved shaft and short point vs curved shaft and elongate point extending just past the tip of the superficial anchor root). The complexity of potential hosts for species of Urocleidoides and their effect on its distribution on profundulid and poeciliid fishes are briefly discussed., Edgar F. Mendoza-Franco, Juan Manuel Caspeta-Mandujano, Guillermo Salgado-Maldonado, Wilfredo Antonio Matamoros., and Obsahuje bibliografii
Two closely related parasitoid wasp species with different host specificities were used for experimental studies on the biology of host finding, a crucial element of parasitoid life history: The habitat and host specialist Nasonia vitripennis and the habitat and host generalist Dibrachys microgastri (Chalcidoidea: Pteromalidae). The host finding parameters tested included reaction to olfactory cues, aspects of locomotor activity, ability to locate hidden hosts and day-night-activity. The results revealed distinct interspecific differences that match the respective host and habitat ranges of the two species. In N. vitripennis host finding is dominated by olfactory reaction to hosts and host habitat, i.e., fly puparia and birds' nests. In D. microgastri olfactory cues have only a minor role. Its host finding is characterized by rapid searching at random. Both species are able to locate hidden hosts. Although still incomplete, these insights into host finding by two parasitoid species with different life history strategies indicate they can be characterized by specific combinations of behavioural host finding features. and Ralph S. Peters.
This article refers to the rich vegetation on the rocky slopes along the Achensee (Tyrol, Northern calcareous Alps, Karwendelalpen) described by Professor Anton Kerner 150 years ago. The vegetation today is much less diverse, the subalpine species abundant in the last centuries are absent while the species of mixed mountainous forest prevail. The abundance of the Heather (Calluna vulgaris), which was not mentioned by A. Kerner, may indicate acidification due to acid rain. And the retreat of subalpine species may indicate the on going change to a warmer climate. and Jarmila Kubíková.
Retroviry jsou jednoduché RNA viry, které se vyznačují schopností přepsat svou RNA do dvouřetězcové DNA a tu stabilně začlenit do genetické informace hostitelské buňky. Tato jejich vlastnost stojí za latencí viru HIV, která v současnosti představuje hlavní překážku v úspěšné léčbě HIV pozitivních pacientů. Na druhou stranu lze této jejich vlastnosti využít pro přenos genetické informace za účelem léčby četných chorob s využitím přístupů genové terapie. Pro tyto účely je však potřeba retroviry vybavit sekvencemi, které zajistí jejich stabilní aktivitu a ochrání je před umlčením., Retroviruses are simple RNA viruses, which exhibit an ability to convert their RNA to double-stranded DNA and introduce it into the host cell genome. This ability stands behind the HIV latency phenomenon - a major obstacle to successful therapy. On the other hand, this capability can be utilized for the transfer of genetic information in order to cure various diseases using gene therapy approaches. To achieve successful therapy, the retroviruses need to be equipped with sequences protecting them from silencing, thus stabilizing their activity., and Filip Šenigl.
A large outbreak of haemolytic uraemic syndrome and bloody diarrhoea caused by the pathogenic E. coli strain in Germany in 2011 has increased attention to foodborne diseases – bacterial infections linked to the consumption of fresh produce. Since the early 1990s, evidence is emerging that en - teropathogenic bacteria have the ability to grow and persist on crop plants for prolonged periods of time, including until harvest, and to be the carrier of illness. and Václav Kůdela.