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Dermanyssus gallinae (De Geer 1778), commonly named the poultry red mite (PRM), is considered to be the most harmful ectoparasite in poultry farms in Europe. This species feeds on the blood of laying hens, but spends most of its time hidden in cracks and crevices around hen nests. To control PRM populations in poultry houses, chemical pesticides are currently used; however, concern is growing regarding the harmful residues found in eggs and hens, along with the increased resistance of mites against several compounds. Alternatives to synthetic compounds are now being explored, including vaccines, biological control, physical control and semiochemical control based on the chemical ecology of PRM. This review focused on the different volatile organic compounds (VOCs) identified from D. gallinae and other mite species that have been discovered to control them. Pheromones (aggregation pheromone, sex pheromone and alarm pheromone) and kairomones promoting attraction behaviour in D. gallinae and other mite species are presented, while VOCs from essential oils and plant extracts with repellent properties are also explored. Finally, devices using VOCs on PRM in the field are described, with devices that have been tested on other Acari species being mentioned as potential directions for the future control of PRM.
The poultry red mite, Dermanyssus gallinae, is currently the most common ectoparasite affecting egg-laying hens. Since continuous culture of D. gallinae on birds is a biologically and economically costly endeavour, storage techniques for mites are urgently needed. Effects of temperature on adult and nymph survival were first studied to optimize storage conditions. Then, fecundity of D. gallinae was studied after mites were stored at optimal storage conditions. Results showed the survival rates of protonymphs (42.11%), deutonymphs (8.19%) and females (19.78%) at 5°C after 84 days were higher than those at 0, 25 and 30°C. Thereafter the fecundity and the capability of re-establishing colonies of D. gallinae were evaluated after they were stored for 40 and 80 days at 5°C. After storage, the mean number of eggs showed no statistical difference between treated (5°C for 40 or 80 days) and control groups (25°C for 7 days), while the hatching rates of eggs were in all cases above 97%. The dynamic changes of mite populations and egg numbers showed similar trends to the control group after the stored adult or nymph mites were fed on chicks. Dermanyssus gallinae can be successfully stored at 5°C for 80 days with no interference with the fecundity of mites, and the stored mites could re-establish colonies successfully. Adults and nymphs were two main stages with capability for low temperature storage. These results suggest that low temperature storage is a viable option for colony maintenance of D. gallinae under laboratory conditions.
Due to side-effects and inefficiency of the drugs used in malaria treatment, finding alternative medicine with less side-effects has attracted much attention. In this regard, in the present study, nanocomposite synthesized and its effects on the metabolites of P. falciparum were investigated. Subsequent to synthesis of nanocomposites, characterization was carried out using nuclear magnetic resonance (NMR), liquid chromatography-mass spectrometry (LC-MS), scanning electron microscopy, dynamic light scattering and Fourier-transform infrared tests. Solubility and drug release were measured and its toxicity on Vero cell was assessed using the MTT assay. The antiparasitic effect of the nanocomposite on the metabolites of P. falciparum was investigated by 1H NMR spectroscopy. Among synthesized nanocomposites, the average size of 239 nm showed suitable solubility in water as well as slow drug release. The MTT assay showed no toxicity for Vero cell lines. Concentrations of 2.5 μg mL−1 of nanocomposite eliminated 82.6% of the total parasites. The most effected metabolic cycles were glyoxylate and dicarboxylate metabolism. In this study, 1H NMR spectroscopy was used with untargeted metabolomics to study the effect of the nanocomposite on P. falciparum. Playing an essential role in understanding drug-target interactions and characterization of mechanism of action or resistance exhibited by novel antiprotozoal drugs, can be achieved by targeting metabolic using LC-MS.
Trichomonas vaginalis (Tv) induces host cell damage through cysteine proteinases (CPs) modulated by iron. An immunoproteomic analysis showed that trichomoniasis patient sera recognize various CPs, also some of them are present in vaginal washes (VWs). Thus, the goal of this work was to determine whether TvCP2 is expressed during infection and to assess the effect of iron on TvCP2 expression, localization and contribution to in vitro cellular damage. Western-blotting (WB) assays using TvCP2r and vaginitis patient serum samples showed that 6/9 Tv (+) but none of the Tv (−) patient sera recognized TvCP2r. WB using an anti-TvCP2r antibody and VWs from the same patients showed that in all of the Tv (+) but none of the Tv (−) VWs, the anti-TvCP2r antibody detected a 27 kDa protein band that corresponded to the mature TvCP2, which was confirmed by mass spectrometry analysis. Iron decreased the amount of TvCP2 mRNA and the protein localized on the parasite surface and cytoplasmic vesicles concomitant with the cytotoxic effect of TvCP2 on HeLa cells. Parasites pretreated with the anti-TvCP2r antibody also showed reduced levels of cytotoxicity and apoptosis induction in HeLa cell monolayers. In conclusion, these results show that TvCP2 is expressed during trichomonal infection and plays an important role in the in vitro HeLa cell cytotoxic damage under iron-restricted conditions.
To assess the role of white-tailed deer (Odocoileus virginianus, WTD) in the epidemiology of toxoplasmosis, we conducted a national survey of WTD across the USA for Toxoplasma gondii infection. To do this, we combined serology with parasite isolation to evaluate the prevalence and genetic diversity of T. gondii in this game species. From October 2012 to March 2019, serum and tissues were collected from 914 WTD across the USA. Serum samples were screened for antibodies to T. gondii, and then the tissues of seropositive WTD were bioassayed in mice. Antibodies were detected in 329 (36%) of 914 WTD tested by the modified agglutination test (positive reaction at 1:25 or higher). Viable T. gondii was isolated from the heart of 36 WTD from 11 states. Three of the 36 isolates were pathogenic but not highly virulent to outbred Swiss Webster mice and all 36 isolates could be propagated further in cell culture and were genotyped. For genotyping, DNA extracted from cell culture-derived tachyzoites was characterized by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using the genetic markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico. Genotyping revealed seven ToxoDB PCR-RFLP genotypes, including 24 isolates for genotype #5 (haplogroup 12), four isolates for #2 (type III, haplogroup 3), three isolates for genotypes #1 (type II, haplogroup 2), two isolates for genotypes #3 (type II, haplogroup 2) and one isolate each for #39, #221 and #224. Genotype #5 was the most frequently isolated, accounting for 66.6% (24 of 36) of the isolates. Combining the 36 isolates from this study with previously reported 69 isolates from WTD, 15 genotypes have been identified. Among these, 50.4% (53/105) isolates belong to genotype #5. Our results indicate moderate genetic diversity of T. gondii in WTD. The results also indicate that undercooked venison should not be consumed by humans or fed to cats.
Free-living amoebae (FLA) are widely dispersed in the environment, can cause opportunistic and non-opportunistic infections in humans and other animals. The aim of the present study was characterize FLA obtained from air-conditioners of a public hospital in the city of Florianópolis, SC, Brazil. Fifty-four dust samples were collected of air conditioners, and were inoculated on 1.5% non-nutrient agar, overlaid with layers of Escherichia coli. Subsequently the isolates were axenised in PYG growth medium. The morphological and molecular characterization of the isolates was performed, as well as the tolerance (physiological) assays were used to evaluate the pathogenic potential. The results revealed the presence of FLA in 42 (77.8%) of the collected samples. Of these, 39 (92.9%) axenic isolates of FLA were obtained for morphological and genotypic studies. All the isolates characterized belong to the genus Acanthamoeba. Nineteen (48.7%) isolates belong to the genotype T4, 16 (41.0%) to the T5 genotype and 4 (10.3%) to genotype T11. Seven (18.0%) isolates were considered potentially pathogenic in tolerance assays. These findings require attention, considering the isolation environment and immunocompromised characteristics of many hospitalized patients.
The control of gastrointestinal nematodes among ruminants maintained in zoological parks remains difficult due to infective stages develop in the soil. For the purpose to improve the possibilities of the control of gastrointestinal nematodes (genera Trichostrongylus, Nematodirus, Chabertia and Haemonchus) affecting wild captive bovidae ruminants belonging to the subfamilies Antilopinae, Caprinae, Bovinae and Reduncinae, commercial pelleted feed enriched with a blend of 104–105 spores of both filamentous fungi Mucor circinelloides + Duddingtonia flagrans per kg meal was provided for a period of 3.5 years. All animals were dewormed at the beginning of the trial and also when exceeding a cut-off point of 300 eggs per gram of feces (EPG). The anthelmintic efficacy ranged between 96 and 100%. The need for repeating the administration of parasiticide treatment disappeared at the 24th month of study in the Antilopinae individuals, and at the 8th month in the Caprinae, Bovinae and Reduncinae. No side-effects were observed on the skin or in the digestive, respiratory or reproductive system. It was concluded that this strategy provides a sustainable tool for preventing the contamination of paddocks where captive ruminants are maintained, decreasing the risk of infection by gastrointestinal nematodes and consequently the need of frequent deworming.
Neurotoxocariasis (NT) is a serious condition that has been linked to reduced cognitive function, behavioural alterations and neurodegenerative diseases. Unfortunately, the available drugs to treat toxocariasis are limited with unsatisfactory results, because of the initiation of treatment at late chronic stages after the occurrence of tissue damage and scars. Therefore, searching for a new therapy for this important disease is an urgent necessity. In this context, cytotherapy is a novel therapeutic approach for the treatment of many diseases and tissue damages through the introduction of new cells into the damaged sites. They exert therapeutic effects by their capability of renewal, differentiation into specialized cells, and being powerful immunomodulators. The most popular cell type utilized in cytotherapy is the mesenchymal stem cells (MSCs) type. In the current study, the efficacy of MSCs alone or combined with albendazole was evaluated against chronic brain insults induced by Toxocara canis infection in an experimental mouse model. Interestingly, MSCs combined with albendazole demonstrated a healing effect on brain inflammation, gliosis, apoptosis and significantly reduced brain damage biomarkers (S100B and GFAP) and T. canis DNA. Thus, MSCs would be protective against the development of subsequent neurodegenerative diseases with chronic NT.
Pregnancy is considered a period in which immunomodulation occurs, although it is important for the maintenance of the foetus, could contribute to infections as Toxoplasma gondii. Immune response cells such as regulatory T cells participate in this immunomodulation, and surface molecules such as CTLA-4 develop an immunosuppressive role, could contribute to the establishment of the parasite. This study aimed to evaluate the presence of regulatory T cells and the expression of CTLA-4 in parturient and non-pregnant seropositive and seronegative for anti-T. gondii antibodies. Sixty-two participants were evaluated, 14 parturient with negative serology, 23 parturient with positive serology, 16 non-pregnant women seronegative and 9 non-pregnant women seropositive. Immunophenotyping was performed for characterize TCD4+Foxp3+ cells, T CD4+CD25-Foxp3+, TCD4+CD25highFoxp3+, TCD4+CTLA-4+, TCD4+CD25-CTLA-4+ and TCD4+CD25highCTLA-4+. We observed a lower level of CD4+CD25highFoxp3+ cells from seropositive parturient compared with seropositive non-pregnant cells. Significative levels of CD4+CD25-Foxp3+ cells from seronegative pregnant were observed compared with seropositive pregnant cells. Furthermore, the higher level of CD4+CD25-CTLA-4+ cells populations was detected in seropositive pregnant cells compared with seropositive non-pregnant. Although a significant increase in CTLA-4 cells was observed in pregnant women positive for anti-T. gondii antibodies, this increase did not cause a risk of reactivation of the infection.
Cochliomyia hominivorax larvae cause myiasis in animals and humans. To register a commercial product to control this dipteran is necessary to experiment on animals. The in vitro test was standardized to evaluate the larvicidal efficacy of commercial topical products. Five formulations were analysed in vitro and in vivo. For the in vitro test, a colony was formed and three replicates (n = 200) of each larval stage (L1, L2 and L3) were treated. The viability of the larvae was evaluated after 5 and 30 min, and at 1, 2, 6, 12, 24, 48, 60 and 72 h post-treatment (HPT). For the in vivo test, 30 bovines divided into six groups were castrated to achieve natural infestation with C. hominivorax. Animals in the treated groups received the product. Myiasis and efficacy were evaluated 12, 24, 36, 48, 60 and 72 HPT. Four formulations tested in the in vitro test achieved 100% efficacy at 24 HPT. In the in vivo experiment only one achieved 100% efficacy at 24 HPT. However, all products achieved the maximum efficacy by the end of study. The in vitro test developed here could be adopted to evaluate the efficacy of topical products for the control of C. hominivorax larvae.
Neurocysticercosis (NCC) is the most common helminthic brain infection related to epilepsy. Only albendazole (ABZ) and praziquantel are used in its treatment. The development of new therapeutics has been encouraged. Taenia crassiceps cysticerci intracranial infection is the experimental model used in NCC studies. This study evaluated the histopathology of the brains of BALB/c mice experimentally infected with T. crassiceps cysticerci after the treatment with the ABZ/nitazoxanide (NTZ) combination. Thirty days after the inoculation the mice received an oral single dose of the ABZ/NTZ combination (40 mg kg−1 each). The control groups were treated with: NaCl 0.9%; ABZ or NTZ. The histopathologic evaluation of the brains was performed 24 h after treatment. The ABZ treatment induced discrete mononuclear inflammatory infiltration, meningitis, gliosis, hyperaemia and hippocampus compression; moderate ependimitis and oedema. The NTZ treatment induced accentuated inflammatory infiltration, foamy macrophages, ependimitis, choroiditis, gliosis and hyperaemia and moderate oedema. The ABZ/NTZ combination treatment induced a significant decrease in the polymorphonuclear inflammatory infiltration, ependimitis, choroiditis, gliosis, hyperaemia and ventriculomegaly in comparison with the other groups. The cysticerci showed destruction of the tegument not observed in other groups. The ABZ/NTZ combination is efficient as the parasite showed signs of destruction and lower damage to the host's tissue.
Data presented in this work represents the first record of parasites from the Alpine and Pyrenean Lagopus muta subspecies, providing valuable information to consider for conservation management. From 1987 to 2018, 207 Rock ptarmigans were collected in the framework of a long-term sanitary monitoring in France. Eight parasites were found in the Alpine Rock ptarmigan, and one in the Pyrenean subspecies. Only two parasites occurred with high prevalence in the Alpine Rock ptarmigan: Capillaria caudinflata (38.9%) and Eimeria sp. (34.7%). Prevalence of the other parasites (Ascaridia compar, Cestodes, Amphimerus sp. and Trichostrongylus tenuis) was lower than 20%. Dispharynx nasuta was found with a prevalence of 52.9% in the Pyrenean Rock ptarmigan. Overall, we found a spatially aggregated distribution of parasites in the northern French Alps, probably due to both favourable climatic conditions for parasite cycle and high host density. Statistical analyses indicated a positive effect of altitude and latitude on C. caudinflata occurrence whereas risk factors for Eimeria sp. were the distance from urban areas and land cover. In addition, the majority of the infested birds came from areas close to ski-pistes, where human disturbance increases the susceptibility to diseases, causing stress to wildlife.