Κυριακή 25 Αυγούστου 2019

A formulation of neem and hypericum oily extract for the treatment of the wound myiasis by Wohlfahrtia magnifica in domestic animals
The given names and family names of the authors of the originally published version of this article was inadvertently interchanged. Correct presentation of the author names are presented here.

Occurrence of Enterocytozoon bieneusi in Chinese Tan sheep in the Ningxia Hui Autonomous Region, China

Abstract

Enterocytozoon bieneusi is a zoonotic parasite which is considered to be an opportunistic pathogen of humans and animals. A number of studies have reported E. bieneusi infection in various animals. However, no information is available on the occurrence of E. bieneusi in Tan sheep, a unique indigenous sheep species in the Ningxia Hui Autonomous Region, China. The objectives of the present study were to examine the prevalence and identify the genotypes of E. bieneusi in Tan sheep in China. A total of 1014 fecal specimens of Tan sheep from six farms in the Ningxia Hui Autonomous Region were examined by nested PCR amplification of the internal transcribed spacer (ITS) of nuclear ribosomal DNA. The total prevalence of E. bieneusi was 12.2% (124/1014), ranging from 0.5 to 22.2% on six farms. Sequence analysis identified 10 genotypes of E. bieneusi, including three known genotypes, BEB6, COS-I, and CHG13, and seven novel genotypes designated as NX1 to NX7, which all belonged to group 2 by phylogenetic analysis. This is the first report describing the prevalence of E. bieneusi in Tan sheep, and the new genotypes identified in the current study expand the genotype distribution of E. bieneusi. These findings provide baseline data and have implications for the epidemiology and control of E. bieneusi infection in Tan sheep.

Motility and cytoskeletal organisation in the archigregarine Selenidium pygospionis (Apicomplexa): observations on native and experimentally affected parasites

Abstract

Representatives of Apicomplexa perform various kinds of movements that are linked to the different stages of their life cycle. Ancestral apicomplexan lineages, including gregarines, represent organisms suitable for research into the evolution and diversification of motility within the group. The vermiform trophozoites and gamonts of the archigregarine Selenidium pygospionis perform a very active type of bending motility. Experimental assays and subsequent light, electron, and confocal microscopic analyses demonstrated the fundamental role of the cytoskeletal proteins actin and tubulin in S. pygospionis motility and allowed us to compare the mechanism of its movement to the gliding machinery (the so-called glideosome concept) described in apicomplexan zoites. Actin-modifying drugs caused a reduction in the movement speed (cytochalasin D) or stopped the motility of archigregarines completely (jasplakinolide). Microtubule-disrupting drugs (oryzalin and colchicine) had an even more noticeable effect on archigregarine motility. The fading and disappearance of microtubules were documented in ultrathin sections, along with the formation of α-tubulin clusters visible after the immunofluorescent labelling of drug-treated archigregarines. The obtained data indicate that subpellicular microtubules most likely constitute the main motor structure involved in S. pygospionis bending motility, while actin has rather a supportive function.

Impacts of long-term insecticide treatment regimes on skdr and kdr pyrethroid resistance alleles in horn fly field populations

Abstract

We evaluated the effects of four different 6-year duration control strategies on the resistance levels and frequency of the pyrethroid target site resistance alleles, superkdr (skdr) and kdr, at four field populations of Haematobia irritans irritans (Linnaeus, 1758) (Diptera: Muscidae) in Louisiana, USA. Consecutive use of pyrethroid ear tags for 6 years caused a significant increase in the resistance ratio to pyrethroids as well as the frequencies of both skdr and kdr resistance alleles. After 3 years of consecutive use of pyrethroid ear tags, followed by 1 year with no treatment, and followed by 2 years with organophosphate ear tags, the resistance ratio for pyrethroid was not significantly affected, the %R-skdr significantly dropped while the %R-kdr allele remained relatively high and stable. Similar results were observed when pyrethroid ear tags were used for three consecutive years, followed by 1 year with no treatment, and followed by 2 years with endosulfan ear tags; however, this treatment resulted in a slight increase in the resistance ratio for pyrethroids. In a mosaic, the resistance ratio for pyrethroids showed a 2.5-fold increase but the skdr-kdr genetic profiles did not change, as the %R alleles (skdr and kdr) remained low and stable through the 6 years. Lack of exposure to pyrethroid insecticides for 3 years significantly affected the skdr mutation but not the kdr mutation, preventing re-establishment of susceptibility to pyrethroids. SS-SR (skdr-kdr) individuals were responsible for the maintenance of the kdr mutation in two of the populations studied, and fitness cost seems to strongly affect the SR-RR genotype. None of the four treatment regimens evaluated in the study had satisfactory results for the management of kdr resistance alleles.

Morphological and molecular description of Sarcocystis ratti n. sp. from the black rat ( Rattus rattus ) in Latvia

Abstract

Rodents have been widely studied as intermediate hosts of Sarcocystis; however, only a few reports on these parasites in the black rat (Rattus rattus) are known. Having examined 13 black rats captured in Latvia, sarcocysts were found in skeletal muscles of two mammals and were described as Sarcocystis ratti n. sp. Under a light microscope, sarcocysts were ribbon-shaped, 0.9–1.3 × 0.09–0.14 mm in size and had a thin (0.8–1.3 μm) and smooth cyst wall. The lancet-shaped bradyzoites were 8.3 × 4.3 (7.5–9.3 × 3.9–4.8) μm. Under a transmission electron microscope, the cyst wall was up to 1.3 μm thick, wavy, the ground substance appeared smooth, type 1a-like. Morphologically, sarcocysts of Sratti were somewhat similar to those of ScymruensisSrodentifelis, and Sdispersa-like previously identified in the brown rat (Rattus norvegicus). On the basis of 18S rDNA, 28S rDNA, and cox1, significant genetic differences (at least 2.3, 4.5, and 5.8%, respectively) were observed when comparing Sratti with other Sarcocystis species using rodents as intermediate hosts. While ITS1 sequences of Sratti were highly distinct from other Sarcocystis species available in GenBank. Phylogenetic and ecological data suggest that predatory mammals living near households are definitive hosts of Sratti.

Insecticide resistance in stable flies ( Stomoxys calcitrans ) on dairy farms in Germany

Abstract

Stable flies (Stomoxys calcitrans Linnaeus, 1758) can have a considerable negative impact on animal well-being, health, and productivity. Since insecticides constitute the mainstay for their control, this study aimed at assessing the occurrence of insecticide resistance in Scalcitrans on dairy farms in Brandenburg, Germany. First, the susceptibility of stable flies from 40 dairy farms to a deltamethrin-impregnated fabric was evaluated using the FlyBox® field test method. Then, Scalcitrans strains from 10 farms were reared in the laboratory, and the offspring was tested against the adulticides deltamethrin and azamethiphos and the larvicides cyromazine and pyriproxyfen. The FlyBox® method indicated 100% resistance in stable flies against deltamethrin. Later, to the offspring of those 10 established laboratory strains previously caught on suspected dairy farms, these field findings could be confirmed with mortalities well below 90% 24 h following topical application of the calculated LD95 of deltamethrin and azamethiphos. The ten strains could therefore be classified as resistant to the tested insecticides. In contrast, exposure to the insect growth regulators cyromazine and pyriproxyfen at their recommended concentrations demonstrated 100% efficacy. Both larvicides inhibited the moulting process of the stable fly larval stages completely, showing that the stable fly strains tested were susceptible to them. The intensive use of insecticides in recent decades has probably promoted the development of insecticide resistance. Systematic surveys in different livestock production systems and vigilance are therefore deemed necessary for estimating the risk of insecticide resistance development on a nationwide scale.

Monunguis streblida (Neothrombidiidae) in Brazil and its parasitic relationships with dipteran ectoparasites ( Anastrebla and Trichobius ) of bats

Abstract

The mite species Monunguis streblida Wharton, 1938 (Neothrombidiidae) is reported in association with dipteran ectoparasites (Streblidae) of Brazilian bats for the first time. A 1-year study of two populations of the bat Anoura geoffroyi Gray, 1838 in caves in the state of Minas Gerais, Brazil, found them to be parasitized by four species of streblids, three of which were parasitized by M. streblida. Three hundred and thirty-two individuals of M. streblida were collected in association with 135 individuals of Anastrebla modestini Wenzel, 1966, two individuals of A. caudiferae Wenzel, 1976, and two individuals of Trichobius sp. (dugesii complex). The predominant association of M. streblida with A. modestini suggests a preference for this host for the larvae of this mite. Fluctuations in the abundance of mites were found to accompany seasonal cycles and fluctuations in the abundance of their main host, with the mites being more abundant in months with higher temperatures and greater rainfall. The present work represents the first formal record of the occurrence of M. streblida in South America, increasing its range of occurrence southward by more than 5000 km.

Eye fluke ( Tylodelphys clavata ) infection impairs visual ability and hampers foraging success in European perch

Abstract

Visual performance and environmental conditions can influence both behavioral patterns and predator-prey interactions of fish. Eye parasites can impair their host’s sensory performance with important consequences for the detection of prey, predators, and conspecifics. We used European perch (Perca fluviatilis) experimentally infected with the eye fluke Tylodelphys clavata and evaluated their feeding behavior and competitive ability under competition with non-infected conspecifics, in groups of four individuals, for two different prey species (Asellus aquaticus and Daphnia magna). To test whether the effect of T. clavata infection differs at different light conditions, we performed the experiments at two light intensities (600 and 6 lx). Foraging efficiency of perch was significantly affected by infection but not by light intensity. The distance at which infected fish attacked both prey species was significantly shorter in comparison to non-infected conspecifics. Additionally, infected fish more often unsuccessfully attacked A. aquaticus. Although the outcome of competition depended on prey species, there was a general tendency that non-infected fish consumed more of the available prey under both light intensities. Even though individual prey preferences for either A. aquaticus or D. magna were observed, we could not detect that infected fish change their prey preference to compensate for a reduced competitive foraging ability. As infection of T. clavata impairs foraging efficiency and competitive ability, infected fish would need to spend more time foraging to attain similar food intake as non-infected conspecifics; this presumably increases predation risk and potentially enhances transmission success to the final host.

Evidence for camels ( Camelus bactrianus ) as the main intermediate host of Echinococcus granulosus sensu lato G6/G7 in Mongolia

Abstract

Cystic echinococcosis (CE), the parasitic disease caused by the larval stage of Echinococcus granulosus sensu lato (s.l.), is a global public health problem. In Mongolia, despite wide distribution of human CE, not enough information is available on the prevalence and molecular characterization of CE in livestock and its zoonotic linkage with human cases. We investigated the distribution of human CE cases and livestock population using statistical models to get insight into the zoonotic linkage. The incidence of human CE cases increased by a factor of 1.71 for one interquartile range increment in the density of the camel population. No significant association was observed with other livestock species. The samples collected from 96 camels and 15 goats in an endemic region showed a CE prevalence of 19.7% and 6.7%, respectively. All livestock CE were E. granulosus s.l. G6/G7 species of the E. granulosus s.l. complex. The genetic diversity was investigated using the haplotype network based on full cox1 gene analysis of the samples collected from livestock CE and nucleotide sequences previously reported from human CE and wild canids infection in Mongolia. Four haplotypes were identified within the livestock samples, two of which had not been previously reported. A common haplotype was identified among humans, camels, goats, and a wolf, all of which were within the same geographical area. A mixed infection of E. granulosus s.l. G6/G7 with different haplotypes in the intermediate host was identified. To the best of our knowledge, this is the most comprehensive description of the current epidemiological situation of CE in Mongolia with substantial evidence that camels might be the main intermediate host of E. granulosus s.l. G6/G7 in Mongolia. Moreover, our result presents the first report in the country to provide insight into the prevalence of E. granulosus s.l. G6/G7 in livestock.

Screening of wild ruminants from the Kaunertal and other alpine regions of Tyrol (Austria) for vector-borne pathogens

Abstract

Knowledge about vector-borne pathogens important for human and veterinary medicine in wild ruminants in Tyrol (Austria) is scarce. Blood samples from Alpine ibex (Capra ibexn = 44), Alpine chamois (Rupicapra rupicapran = 21), roe deer (Capreolus capreolusn = 18) and red deer (Cervus elaphusn = 6) were collected over a period of 4 years (2015–2018) in four regions in North Tyrol, with a primary focus on the Kaunertal. Blood spots on filter paper were tested for the presence of DNA of vector-borne pathogens (Anaplasmataceae, Piroplasmida, Rickettsia and filarioid helminths). Anaplasma phagocytophilum and Babesia capreoli were detected in two of 89 (2.3%) blood samples. Rickettsia spp., Theileria spp. and filarioid helminths were not documented. One Alpine chamois was positive for A. phagocytophilum and B. capreoli. Moreover, an ibex from the Kaunertal region was positive for A. phagocytophilum. While the ibex was a kid less than 1 year old, the chamois was an adult individual. Further research is recommended to evaluate effects of climate change on infection rates of North Tyrolean wild ruminants by these pathogens and the distribution of their vectors.

Δεν υπάρχουν σχόλια:

Δημοσίευση σχολίου