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1.
Nat Commun ; 13(1): 5778, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36182919

RESUMO

Toxoplasma gondii is a cyst-forming apicomplexan parasite of virtually all warm-blooded species, with all true cats (Felidae) as definitive hosts. It is the etiologic agent of toxoplasmosis, a disease causing substantial public health burden worldwide. Few intercontinental clonal lineages represent the large majority of isolates worldwide. Little is known about the evolutionary forces driving the success of these lineages, the timing and the mechanisms of their global dispersal. In this study, we analyse a set of 156 genomes and we provide estimates of T. gondii mutation rate and generation time. We elucidate how the evolution of T. gondii populations is intimately linked to the major events that have punctuated the recent history of cats. We show that a unique haplotype, whose length represents only 0.16% of the whole T. gondii genome, is common to all intercontinental lineages and hybrid populations derived from these lineages. This haplotype has accompanied wildcats (Felis silvestris) during their emergence from the wild to domestic settlements, their dispersal in the Old World, and their expansion in the last five centuries to the Americas. The selection of this haplotype is most parsimoniously explained by its role in sexual reproduction of T. gondii in domestic cats.


Assuntos
Felidae , Toxoplasma , Toxoplasmose Animal , América , Animais , Gatos , Haplótipos , Toxoplasma/genética , Toxoplasmose Animal/parasitologia
2.
Vet Parasitol Reg Stud Reports ; 35: 100779, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36184108

RESUMO

Rodents are one of the most relevant groups of mammals involved in the process of zoonotic disease transmission. Their ability to adapt to anthropized environments allows them to come into contact with humans with often negative consequences for the latter. The present study designed to detect the presence of Trypanosoma cruzi and Leishmania spp. in rodents living in the peri-urban area of Queretaro in central Mexico. This research was carried out during two seasons of collection of wild and domestic rodents, in three localities within the peri-urban area of the state of Queretaro. These collections were carried out during the dry season of February-May 2017 and in the rainy season of August-November 2017. Samples were obtained from the tail tip, from which DNA was purified using the DNeasy Blood & Tissue Kit. End-point PCR was used for the identification of Trypanosoma cruzi and Leishmania spp. A total of 82 rodents were caught, represented in three families, six genera and seven species, of which 29 (35.3%) were positive for Trypanosoma cruzi; 13 (15.8%) for Leishmania spp.; and 12 individuals presented co-infection with both parasites (14.6%). This study confirmed the presence of Trypanosoma cruzi and Leishmania spp. in synanthropic rodents in the peri-urban area of Queretaro, where Chagas and Leishmaniosis diseases are not considered endemic. It is necessary to continue researching for the presence of vectors, as well as for the detection of diseases caused by parasites in humans and thus be able to confirm the transmission cycle of Trypanosoma cruzi and Leishmania spp. in this central Mexican city.


Assuntos
Doença de Chagas , Leishmania , Doenças dos Roedores , Trypanosoma cruzi , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Doença de Chagas/veterinária , Humanos , Leishmania/genética , Mamíferos/parasitologia , México/epidemiologia , Doenças dos Roedores/epidemiologia , Roedores , Trypanosoma cruzi/genética
3.
Vet Parasitol Reg Stud Reports ; 35: 100782, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36184111

RESUMO

Pentastomes are crustacean endoparasites in the lungs of herpetofauna and rarely mammals and birds. To date, the only pentastomes reported in chelonians, all aquatic turtles, are Diesingia megastomum from Brazil and Pelonia africana from South Africa. In March 2021, 185 juvenile tortoises (Chelonoidis niger) were confiscated after an attempted illegal exportation from the Galápagos. It is believed the tortoises were removed from nests on Santa Cruz Island. The young tortoises were individually wrapped in plastic and at seizure ten were dead and another 25 tortoises subsequently died. One of the tortoises, estimated to be 3 months old, had 11 pentastomes in the lungs. The pentastomes were identified as a Raillietiella sp. based on morphology. The specimens had a claviform body that tapers into a bifid tail, a 165.3 µm × 92.1 µm buccal cadre, and sharp tipped anterior and posterior hooks with the posterior hooks being larger than the anterior. The males have smooth copulatory spicules with a rounded, smooth base. All females were gravid. Molecular analysis confirmed that the parasites were a Raillietiella sp. Based on the COI gene, it was most similar (82.7% identical) to an undescribed Raillietiella species from a Caribbean anole (Anolis cristatellus) found in Florida followed by R. hebitihamata (81%), R. indica (80.7%), and R. orientalis (78.8-80.7%). Based on the 18S rRNA gene sequence (1799 bp), it was most similar (99.3% identical) to two undescribed Raillietiella species followed by R. aegypti from a berber skink (Eumeces schneideri) from Saudia Arabia. Phylogenetically, with both molecular targets, the Raillietiella sp. from the Galápagos tortoise grouped with other Raillietiella spp. and was basal within the group. Currently, the origin of this parasite (native to Galápagos or introduced) and the life cycle are unknown. Because some pentastome species, especially when in aberrant hosts, can be pathogenic, additional studies of parasites in native and introduced reptile and amphibian species in the Galápagos are needed to better understand the risk this parasite poses to Galápagos tortoises.


Assuntos
Artrópodes , Lagartos , Pentastomídeos , Tartarugas , Animais , Feminino , Masculino , Mamíferos , Níger , Plásticos , Tartarugas/genética , Tartarugas/parasitologia
4.
Vet Parasitol Reg Stud Reports ; 35: 100784, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36184112

RESUMO

Neglected tropical diseases pose a threat to domestic animal health, as domestic animals can serve as reservoirs for certain zoonotic parasitic infections, including Guinea worm (Dracunculus medinensis) and lymphatic filariasis. Surveillance for these parasites in domestic animals is needed to understand infection prevalence and transmission cycles, with the goal of instituting appropriate interventions. The goal of this research was to report our finding of Brugia sp. infection in dogs from Chad, Africa, and to characterize the genetics and epidemiology of the parasite. During a recent Chadian canine pathogen surveillance project, we identified Brugia sp. infections in a total of 46 out of 428 dogs (10.7%) sampled at three time points in 2019-2020. We found high levels of sequence similarity to B. malayi and B. pahangi based on amplification of 18S rRNA, 5.8S rRNA, and ITS-2 regions. Phylogenetic analysis of 18S rRNA gene sequences placed the Chadian Brugia sp. in a clade with other Brugia spp. but grouped it separately from both B. malayi and B. pahangi. Analysis of Hha I sequences showed the greatest similarity with B. patei, a parasite previously reported from dogs, cats, and wildlife hosts in Kenya. Epidemiologic analysis using generalized linear regression modeling found significantly higher odds of Brugia sp. detection among dogs in villages in southern Chad compared to those in the northern region. Further, within the northern region, there were higher odds of detection in the dry season, compared to the wet season, which is consistent with the ecology of a presumably mosquito-borne parasite. The same 428 dogs were tested for Dirofilaria immitis antigen using a commercial assay (IDEXX SNAP 4Dx) at the earliest time point of the study, with 119 dogs testing positive. However, no association was noted between Brugia infection and a dog being positive for Di. immitis antigen, with only seven of the 119 Di. immitis antigen-positive dogs being Brugia-positive. This is the first report of Brugia sp. in domestic dogs in Chad and additional research is needed to definitively identify the species present, elucidate transmission, and understand potential risks to canine and human health.


Assuntos
Doenças do Gato , Doenças do Cão , Filariose , Animais , Brugia/genética , Doenças do Gato/parasitologia , Gatos , Chade/epidemiologia , Doenças do Cão/parasitologia , Cães , Dracunculus , Filariose/epidemiologia , Filariose/parasitologia , Filariose/veterinária , Humanos , Filogenia , RNA Ribossômico 18S , RNA Ribossômico 5,8S , Zoonoses
5.
Folia Parasitol (Praha) ; 692022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36185031

RESUMO

Ligula intestinalis (Linnaeus, 1758) is a tapeworm parasite with a worldwide distribution that uses a wide variety of fish species as its second intermediate host. In the present study, we investigated the prevalence and population genetic structure of plerocercoids of L. intestinalis in five common cyprinoid species, roach Rutilus rutilus (Linnaeus), freshwater bream Abramis brama (Linnaeus), white bream Blicca bjoerkna (Linnaeus), bleak Alburnus alburnus (Linnaeus), and rudd Scardinius erythrophthalmus (Linnaeus), collected in six water bodies of the Czech Republic (Milada, Most, Medard, Jordán, Rímov and Lipno). Of the six study sites, the highest frequency of parasitism was recorded in Lake Medard (15%). The overall prevalence rate among the species was as follows: roach > rudd ≥ freshwater bream > bleak > white bream. Two mitochondrial genes (cytb and COI) were used to compare the population genetic structure of parasite populations using selected samples from the five fish species. The results of the phylogenetic analysis indicated that all populations of L. intestinalis were placed in Clade A, previously identified as the most common in Europe. At a finer scale, haplotype network and PCoA analyses indicated the possible emergence of host specificity of several mtDNA haplotypes to the freshwater bream. Moreover, pairwise Fixation indices (FST) revealed a significant genetic structure between the parasite population in freshwater bream and other host species. Parasite populations in roach not only showed the highest rate of prevalence but also depicted a maximum number of shared haplotypes with populations from bleak and rudd. Our results suggest that recent ecological differentiation might have influenced tapeworm populations at a fine evolutionary scale. Thus, the differences in prevalence between fish host species in different lakes might be influenced not only by the parasite's ecology, but also by its genetic diversity.


Assuntos
Cestoides , Infecções por Cestoides , Cyprinidae , Doenças dos Peixes , Parasitos , Animais , Cestoides/genética , Infecções por Cestoides/epidemiologia , Infecções por Cestoides/parasitologia , Infecções por Cestoides/veterinária , Cyprinidae/parasitologia , República Tcheca/epidemiologia , DNA Mitocondrial , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Estruturas Genéticas , Genética Populacional , Interações Hospedeiro-Parasita , Lagos , Filogenia , Prevalência , Água
6.
Folia Parasitol (Praha) ; 692022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36193766

RESUMO

A three-year-old male South China tiger died in the tiger enclosure of the China Tiger Park in the Meihua Mountains on December 2018 after being bitten by a tick. This tiger presented clinical symptoms like whole-body severe jaundice, hepatosplenomegaly, kidney, and lymph node hemorrhages. The Colpodella sp.-specific 18S rRNA gene was detected using nested PCR. Interestingly, the DNA isolated from the blood of the tiger was found to be 100% similar to that of the tick by NCBI BLAST analysis. However, the DNA fragments isolated from the tiger's blood were 90.1% similar to the Colpodella sp. strain human erythrocyte parasite (HEP, MH208621) and 90.4% similar to the Colpodella sp. strain Heilongjiang (HLJ, KT364261). To investigate the species of ticks and ticks-carried Colpodella parasites in this region, the species of ticks obtained from the grasses outside the tiger enclosure and the species of Colpodella carried by ticks were identified. The DNA from ticks as well as that from the tick-borne Colpodella sp. were amplified from each tick using PCR followed by amplicon sequencing. In total 402 adult ticks samples were collected, among which 22 were positive for Colpodella sp. (5.5%), and the species were further determined by morphology, DNA sequencing and phylogenetic analyses. Interestingly, one Colpodella sp. was found to have 94.2% sequence similarities to the Colpodella sp. strain HEP (MH208621). This strain was previously reported to infect a woman in Yunnan, China. In addition, three Colpodella sp. showed 87-91% sequence similarities to the Colpodella sp. strain HLJ (KT364261), which was previously reported to infect human in Heilongjiang, China. This study disclosed the possibility of zoonotic transmission of Colpodella sp. by ticks in China. Finally, it provides a basis for urgently determining and monitoring the repertoire of ticks-borne piroplasmid pathogens, with the ultimate aim of strategic control.


Assuntos
Carrapatos , Tigres , Animais , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Masculino , Filogenia , RNA Ribossômico 18S/genética , Carrapatos/parasitologia , Tigres/genética
7.
Front Cell Infect Microbiol ; 12: 981432, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189342

RESUMO

CRISPR editing has enabled the rapid creation of fluorescent Plasmodium transgenic lines, facilitating a deeper understanding of parasite biology. The impact of genetic perturbations such as gene disruption or the introduction of drug resistance alleles on parasite fitness is typically quantified in competitive growth assays between the query line and a wild type reference. Although fluorescent reporter lines offer a facile and frequently used method to measure relative growth, this approach is limited by the strain background of the existing reporter, which may not match the growth characteristics of the query strains, particularly if these are slower-growing field isolates. Here, we demonstrate an efficient CRISPR-based approach to generate fluorescently labelled parasite lines using mNeonGreen derived from the LanYFP protein in Branchiostoma lanceolatum, which is one of the brightest monomeric green fluorescent proteins identified. Using a positive-selection approach by insertion of an in-frame blasticidin S deaminase marker, we generated a Dd2 reporter line expressing mNeonGreen under the control of the pfpare (P. falciparum Prodrug Activation and Resistance Esterase) locus. We selected the pfpare locus as an integration site because it is highly conserved across P. falciparum strains, expressed throughout the intraerythrocytic cycle, not essential, and offers the potential for negative selection to further enrich for integrants. The mNeonGreen@pare line demonstrates strong fluorescence with a negligible fitness defect. In addition, the construct developed can serve as a tool to fluorescently tag other P. falciparum strains for in vitro experimentation.


Assuntos
Malária Falciparum , Pró-Fármacos , Esterases , Proteínas de Fluorescência Verde/genética , Humanos , Malária Falciparum/parasitologia , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo
8.
Front Cell Infect Microbiol ; 12: 984049, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189362

RESUMO

Malaria parasites are unicellular eukaryotic pathogens that develop through a complex lifecycle involving two hosts, an anopheline mosquito and a vertebrate host. Throughout this lifecycle, the parasite encounters widely differing conditions and survives in distinct ways, from an intracellular lifestyle in the vertebrate host to exclusively extracellular stages in the mosquito. Although the parasite relies on cholesterol for its growth, the parasite has an ambiguous relationship with cholesterol: cholesterol is required for invasion of host cells by the parasite, including hepatocytes and erythrocytes, and for the development of the parasites in those cells. However, the parasite is unable to produce cholesterol itself and appears to remove cholesterol actively from its own plasma membrane, thereby setting up a cholesterol gradient inside the infected host erythrocyte. Overall a picture emerges in which the parasite relies on host cholesterol and carefully controls its transport. Here, we describe the role of cholesterol at the different lifecycle stages of the parasites.


Assuntos
Malária , Parasitos , Animais , Colesterol/metabolismo , Eritrócitos/parasitologia , Estágios do Ciclo de Vida , Malária/parasitologia , Parasitos/metabolismo , Plasmodium falciparum
9.
Front Cell Infect Microbiol ; 12: 934641, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189366

RESUMO

Despite significant developments towards malaria reduction, parasite transmission in the common context of HIV-1 co-infection and treatment for one or both infections has not been fully characterized. This is particularly important given that HIV-1 and malaria chemotherapies have the potential to alter gametocyte burden and mosquito infectivity. In this study, we examined 782 blood samples collected from a longitudinal cohort of 300 volunteers with asymptomatic parasitemia seeking HIV testing or treatment in the endemic region of Kisumu, Kenya, to define the impacts of HIV-1-malaria co-infection, antiretroviral therapy (ART) plus trimethoprim-sulfamethoxazole (TS) and the antimalarials artemether/lumefantrine (AL) on Plasmodium falciparum gametocyte transcript prevalence and parasite transmission to the African malaria mosquito Anopheles gambiae. Volunteers were assigned to three distinct HIV-1 groups: HIV-1 positive on treatment, HIV-1 positive newly diagnosed, and HIV-1 negative. Volunteers were monitored monthly over the course of six months. Using our highly sensitive digital droplet PCR (ddPCR) assay of three gametocyte specific transcript markers, we detected gametocyte transcripts in 51.1% of 18S positive volunteers across all study groups and time points. After correcting for multiple comparisons, the factors of HIV-1 status, time, CD4+ T-cell levels and hematocrit were not predictive of gametocyte prevalence or transmission. However, among those volunteers who were newly diagnosed with HIV-1 and malaria positive by rapid diagnostic test (RDT) at enrollment, the initiation of ART/TS and AL treatment was associated with a significant reduction in gametocyte transcript prevalence in the subsequent month when compared to HIV-1 negative volunteers treated with AL. To assess gametocyte transmissibility, volunteer blood samples were used in standard membrane feeding assays (SFMA) with laboratory-reared A. gambiae, with evidence of transmission confirmed by at least one of 25 dissected mosquitoes per sample positive for at least one midgut oocyst. HIV-1 status, CD4+ T-cell levels and hematocrit were not significantly associated with successful transmission to A. gambiae. Analysis of SMFA blood samples revealed that 50% of transmission-positive blood samples failed to test positive by Plasmodium-specific 18S ribosomal RNA quantitative PCR (qPCR) and 35% failed to test positive for any gametocyte specific transcript marker by droplet digital (ddPCR), documenting that transmission occurred in the absence of molecular parasite/gametocyte detection. Overall, these findings highlight the complexity of HIV-1 malaria co-infection and the need to further define the unpredictable role of asymptomatic parasitemia in transmission to mosquitoes.


Assuntos
Anopheles , Antimaláricos , Coinfecção , Infecções por HIV , HIV-1 , Malária Falciparum , Malária , Animais , Anopheles/parasitologia , Antimaláricos/uso terapêutico , Artemeter , Combinação Arteméter e Lumefantrina/uso terapêutico , Infecções por HIV/complicações , HIV-1/genética , Humanos , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Parasitemia/parasitologia , Plasmodium falciparum/genética , RNA Ribossômico 18S , Combinação Trimetoprima e Sulfametoxazol
10.
J Vis Exp ; (187)2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36190254

RESUMO

Cystic echinococcosis or hydatid disease is one of the most important zoonotic parasitic diseases caused by Echinococcus granulosus, a small tapeworm harbored in the intestine of canines. There is an urgent need for applied genetic research to understand the mechanisms of pathogenesis and disease control and prevention. However, the lack of an effective gene evaluation system impedes direct interpretation of the functional genetics of cestode parasites, including the Echinococcus species. The present study demonstrates the potential of lentiviral gene transient transduction in the metacestode and strobilated forms of E. granulosus. Protoscoleces (PSCs) were isolated from hydatid cysts and transferred to specific biphasic culture media to develop into strobilated worms. The worms were transfected with harvested third-generation lentivirus, along with HEK293T cells as a transduction process control. A pronounced fluorescence was detected in the strobilated worms over 24 h and 48 h, indicating transient lentiviral transduction in E. granulosus. This work presents the first attempt at lentivirus-based transient transduction in tapeworms and demonstrates the promising outcomes with potential implications in experimental studies on flatworm biology.


Assuntos
Equinococose , Echinococcus granulosus , Echinococcus , Animais , Meios de Cultura , Cães , Equinococose/parasitologia , Echinococcus/genética , Echinococcus granulosus/genética , Células HEK293 , Humanos
11.
PLoS Negl Trop Dis ; 16(10): e0010788, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36190932

RESUMO

Host cell invasion is a critical step for infection by Trypanosoma cruzi, the agent of Chagas disease. In natural infection, T. cruzi metacyclic trypomastigote (MT) forms establish the first interaction with host cells. The gp35/50 mucin molecules expressed in MT have been implicated in cell invasion process, but the mechanisms involved are not well understood. We performed a series of experiments to elucidate the mode of gp35/50-mediated MT internalization. Comparing two parasite strains from genetically divergent groups, G strain (TcI) and CL strain (TcVI), expressing variant forms of mucins, we demonstrated that G strain mucins participate in MT invasion. Only G strain-derived mucins bound to HeLa cells in a receptor-dependent manner and significantly inhibited G strain MT invasion. CL strain MT internalization was not affected by mucins from either strain. HeLa cell invasion by G strain MT was associated with actin recruitment and did not rely on lysosome mobilization. To examine the involvement of annexin A2, which plays a role in actin dynamic, annexin A2-depleted HeLa cells were generated. Annexin A2-deficient cell lines were significantly more resistant than wild type controls to G strain MT invasion. In a co-immunoprecipitation assay, to check whether annexin A2 might be the receptor for mucins, protein A/G magnetic beads crosslinked with monoclonal antibody to G strain mucins were incubated with detergent extracts of MT and HeLa cells. Binding of gp35/50 mucins to annexin A2 was detected. Both G strain MT and purified mucins induced focal adhesion kinase activation in HeLa cells. By confocal immunofluorescence microscopy, colocalization of invading G strain MT with clathrin was visualized. Inhibition of clathrin-coated vesicle formation reduced parasite internalization. Taken together, our data indicate that gp35/50-mediated MT invasion is accomplished through interaction with host cell annexin A2 and clathrin-dependent endocytosis.


Assuntos
Anexina A2 , Doença de Chagas , Trypanosoma cruzi , Actinas/metabolismo , Anexina A2/metabolismo , Anticorpos Monoclonais , Doença de Chagas/parasitologia , Clatrina , Detergentes/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Células HeLa , Humanos , Mucinas/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/fisiologia
12.
Parasit Vectors ; 15(1): 323, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36100860

RESUMO

BACKGROUND: Sarcoptes scabiei is globally distributed and one of the most impactful mammalian ectoparasites. Sarcoptic mange, caused by infection with S. scabiei, causes disruption of the epidermis and its bacterial microbiota, but its effects on host fungal microbiota and on the microbiota of marsupials in general have not been studied. Here, we (i) examine bacterial and fungal microbiota changes associated with mange in wild bare-nosed wombats (BNWs) and (ii) evaluate whether opportunistic pathogens are potentiated by S. scabiei infection in this species. METHODS: Using Amplicon Sequencing of the 16S rRNA and ITS2 rDNA genes, we detected skin microbiota changes of the bare-nosed wombat (Vombatus ursinus). We compared the alpha and beta diversity among healthy, moderate, and severe disease states using ANOVA and PERMANOVA with nesting. Lastly, we identified taxa that differed between disease states using analysis of composition of microbes (ANCOM) testing. RESULTS: We detected significant changes in the microbial communities and diversity with mange in BNWs. Severely affected BNWs had lower amplicon sequence variant (ASV) richness compared to that of healthy individuals, and the microbial communities were significantly different between disease states with higher relative abundance of potentially pathogenic microbial taxa in mange-affected BNWs including Staphylococcus sciuri, Corynebacterium spp., Brevibacterium spp., Brachybacterium spp., and Pseudogymnascus spp. and Debaryomyces spp. CONCLUSION: This study represents the first investigation of microbial changes in association with sarcoptic mange in a marsupial host, as well as the first investigation of fungal microbial changes on the skin of any host suffering from sarcoptic mange. Our results are broadly consistent with bacterial microbiota changes observed in humans, pigs, canids, and Iberian ibex, suggesting the epidermal microbial impacts of mange may be generalisable across host species. We recommend that future studies investigating skin microbiota changes include both bacterial and fungal data to gain a more complete picture of the effects of sarcoptic mange.


Assuntos
Marsupiais , Micobioma , Escabiose , Animais , Cabras/parasitologia , Humanos , Marsupiais/parasitologia , RNA Ribossômico 16S/genética , Sarcoptes scabiei/genética , Escabiose/parasitologia , Suínos
13.
Malar J ; 21(1): 264, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36100902

RESUMO

BACKGROUND: Sporozoites isolated from the salivary glands of Plasmodium-infected mosquitoes are a prerequisite for several basic and pre-clinical applications. Although salivary glands are pooled to maximize sporozoite recovery, insufficient yields pose logistical and analytical hurdles; thus, predicting yields prior to isolation would be valuable. Preceding oocyst densities in the midgut is an obvious candidate. However, it is unclear whether current understanding of its relationship with sporozoite densities can be used to maximize yields, or whether it can capture the potential density-dependence in rates of sporozoite invasion of the salivary glands. METHODS: This study presents a retrospective analysis of Anopheles stephensi mosquitoes infected with two strains of the rodent-specific Plasmodium berghei. Mean oocyst densities were estimated in the midguts earlier in the infection (11-15 days post-blood meal), with sporozoites pooled from the salivary glands later in the infection (17-29 days). Generalized linear mixed effects models were used to determine if (1) mean oocyst densities can predict sporozoite yields from pooled salivary glands, (2) whether these densities can capture differences in rates of sporozoite invasion of salivary glands, and (3), if the interaction between oocyst densities and time could be leveraged to boost overall yields. RESULTS: The non-linear effect of mean oocyst densities confirmed the role of density-dependent constraints in limiting yields beyond certain oocyst densities. Irrespective of oocyst densities however, the continued invasion of salivary glands by the sporozoites boosted recoveries over time (17-29 days post-blood meal) for either parasite strain. CONCLUSIONS: Sporozoite invasion of the salivary glands over time can be leveraged to maximize yields for P. berghei. In general, however, invasion of the salivary glands over time is a critical fitness determinant for all Plasmodium species (extrinsic incubation period, EIP). Thus, delaying sporozoite collection could, in principle, substantially reduce dissection effort for any parasite within the genus, with the results also alluding to the potential for changes in sporozoites densities over time to modify infectivity for the next host.


Assuntos
Anopheles , Esporozoítos , Animais , Anopheles/parasitologia , Plasmodium berghei , Estudos Retrospectivos , Glândulas Salivares/parasitologia
14.
Malar J ; 21(1): 265, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36100912

RESUMO

BACKGROUND: Over the last two decades, the scale-up of vector control and changes in the first-line anti-malarial, from chloroquine (CQ) to sulfadoxine-pyrimethamine (SP) and then to artemether-lumefantrine (AL), have resulted in significant decreases in malaria burden in western Kenya. This study evaluated the long-term effects of control interventions on molecular markers of Plasmodium falciparum drug resistance using parasites obtained from humans and mosquitoes at discrete time points. METHODS: Dried blood spot samples collected in 2012 and 2017 community surveys in Asembo, Kenya were genotyped by Sanger sequencing for markers associated with resistance to SP (Pfdhfr, Pfdhps), CQ, AQ, lumefantrine (Pfcrt, Pfmdr1) and artemisinin (Pfk13). Temporal trends in the prevalence of these markers, including data from 2012 to 2017 as well as published data from 1996, 2001, 2007 from same area, were analysed. The same markers from mosquito oocysts collected in 2012 were compared with results from human blood samples. RESULTS: The prevalence of SP dhfr/dhps quintuple mutant haplotype C50I51R59N108I164/S436G437E540A581A613 increased from 19.7% in 1996 to 86.0% in 2012, while an increase in the sextuple mutant haplotype C50I51R59N108I164/H436G437E540A581A613 containing Pfdhps-436H was found from 10.5% in 2012 to 34.6% in 2017. Resistant Pfcrt-76 T declined from 94.6% in 2007 to 18.3% in 2012 and 0.9% in 2017. Mutant Pfmdr1-86Y decreased across years from 74.8% in 1996 to zero in 2017, mutant Pfmdr1-184F and wild Pfmdr1-D1246 increased from 17.9% to 58.9% in 2007 to 55.9% and 90.1% in 2017, respectively. Pfmdr1 haplotype N86F184S1034N1042D1246 increased from 11.0% in 2007 to 49.6% in 2017. No resistant mutations in Pfk13 were found. Prevalence of Pfdhps-436H was lower while prevalence of Pfcrt-76 T was higher in mosquitoes than in human blood samples. CONCLUSION: This study showed an increased prevalence of dhfr/dhps resistant markers over 20 years with the emergence of Pfdhps-436H mutant a decade ago in Asembo. The reversal of Pfcrt from CQ-resistant to CQ-sensitive genotype occurred following 19 years of CQ withdrawal. No Pfk13 markers associated with artemisinin resistance were detected, but the increased haplotype of Pfmdr1 N86F184S1034N1042D1246 was observed. The differences in prevalence of Pfdhps-436H and Pfcrt-76 T SNPs between two hosts and the role of mosquitoes in the transmission of drug resistant parasites require further investigation.


Assuntos
Antimaláricos , Artemisininas , Culicidae , Malária Falciparum , Animais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Artemeter/uso terapêutico , Combinação Arteméter e Lumefantrina/uso terapêutico , Artemisininas/uso terapêutico , Biomarcadores , Cloroquina/farmacologia , Resistência a Medicamentos/genética , Humanos , Quênia/epidemiologia , Malária Falciparum/parasitologia , Mosquitos Vetores , Oocistos , Plasmodium falciparum/genética , Tetra-Hidrofolato Desidrogenase/genética
15.
Biomed Res Int ; 2022: 2881879, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36105932

RESUMO

Plasmodium species is an important causative agent of malaria in the world including Ethiopia, and the majority of people were at risk of infection. The study's general objective was to determine the occurrence and distribution of Plasmodium species in the study area through microscopic examination of blood films. A cross-sectional study was carried out in the study sites from September 2016 to February 2017. Out of 512 participants, 32 (6.25%) were malaria positive. Of these, 17 (53.12%, 95% CI: 0.358, 0.704) were P. vivax, 12 (37.5%, 95% CI: 0.207, 0.543) P. falciparum, and 3 (9.375%, 95% CI: -0.007, 0.195) mixed out of the total positive case. The occurrence of parasites was greater in rural villages (59.375%) than in urban villages (40.625%) but not significant (χ 2 = 1.2917, df = 1, p = 0.2557). More males were infected compared to females but not significant (χ 2 = 0.0005665, df = 1, p = 0.981). The monthly distribution of Plasmodium species was higher in September and October but there was no significant variation in each month (χ 2 = 10.142, p = 0.4281). Due to the high occurrence of Plasmodium vivax in the study area, the result contrasts with the national figure of the Plasmodium species report. The result of the current study may be useful to those individuals who work in Plasmodium species control and prevention program.


Assuntos
Malária Falciparum , Malária Vivax , Malária , Plasmodium , Estudos Transversais , Etiópia/epidemiologia , Feminino , Humanos , Malária/parasitologia , Malária Falciparum/parasitologia , Malária Vivax/epidemiologia , Malária Vivax/parasitologia , Masculino , Prevalência
16.
J Vis Exp ; (186)2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-36063011

RESUMO

Malaria is a major public health concern, presenting more than 200 million cases per year worldwide. Despite years of scientific efforts, protective immunity to malaria is still poorly understood, mainly due to methodological limitations of long-term Plasmodium culture, especially for Plasmodium vivax. Most studies have focused on adaptive immunity protection against malaria by antibodies, which play a key role in controlling malaria. However, the sterile protection induced by attenuated Plasmodium sporozoites vaccines is related to cellular response, mainly to cytotoxic T lymphocytes, such as CD8+ and gamma delta T cells (γδ T). Hence, new methodologies must be developed to better comprehend the functions of the cellular immune response and thus support future therapy and vaccine development. To find a new strategy to analyze this cell-mediated immunity to Plasmodium blood-stage infection, our group established an in vitro assay that measures infected red blood cell (iRBC) killing by cytotoxic lymphocytes. This assay can be used to study cellular immune response mechanisms against different Plasmodium spp. in the blood stage. Innate and adaptative cytotoxic immune cells can directly eliminate iRBCs and the intracellular parasite in an effector:target mechanism. Target iRBCs are labeled to evaluate cell viability, and cocultured with effector cells (CD8+ T, γδ T, NK cells, etc.). The lysis percentage is calculated based on tested conditions, compared to a spontaneous lysis control in a flow cytometry-based assay. Ultimately, this killing assay methodology is a major advance in understanding cell-mediated immunity to blood-stage malaria, helping uncover new potential therapeutic targets and accelerate the development of malaria vaccines.


Assuntos
Vacinas Antimaláricas , Malária , Plasmodium , Animais , Linfócitos T CD8-Positivos , Eritrócitos , Humanos , Malária/parasitologia , Esporozoítos
17.
Dis Aquat Organ ; 151: 37-49, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36106715

RESUMO

Global climate change is altering the abundance and spread of many aquatic parasites and pathogens. Proliferative kidney disease (PKD) of salmonids caused by the myxozoan Tetracapsuloides bryosalmonae is one such emerging disorder, and its impact is expected to increase with rising water temperature. Yet, the distribution and prevalence of T. bryosalmonae in Northern Europe remain poorly characterized. Here, we studied 43 locations in 27 rivers in northernmost Norway and Finland to describe T. bryosalmonae infection frequency and patterns in 1389 juvenile salmonids. T. bryosalmonae was discovered in 12 out of 27 rivers (44%) and prevalence ranged from 4.2 to 55.5% in Atlantic salmon and from 5.8 to 75% in brown trout among infected rivers. In sympatric populations, brown trout was more frequently infected with T. bryosalmonae than was salmon. Age-specific parasite prevalence patterns revealed that in contrast to lower latitudes, the infection of juvenile fish predominantly occurs during the second summer or later. Temperature monitoring over 2 yr indicated that the mean water temperature in June was 2.1 to 3.2°C higher in rivers containing T. bryosalmonae compared to parasite-free rivers, confirming the important role of temperature in parasite occurrence. Temporal comparison in T. bryosalmonae prevalence over a 10 yr period in 11 rivers did not reveal any signs of contemporary parasite spread to previously uninfected rivers. However, the wide distribution of T. bryosalmonae in rivers flowing to the Barents Sea indicates that climate change and heat waves may cause new disease outbreaks in northern regions.


Assuntos
Doenças dos Peixes , Nefropatias , Myxozoa , Parasitos , Doenças Parasitárias em Animais , Salmo salar , Animais , Europa (Continente) , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Nefropatias/parasitologia , Nefropatias/veterinária , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , Prevalência , Truta , Água
18.
Dis Aquat Organ ; 151: 51-60, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36106716

RESUMO

Kudoa inornata is a myxosporean that infects the seatrout Cynoscion nebulosus. Increased prevalence of infection as fish age and absence of inflammation against plasmodia led to the hypothesis that seatrout retain and accumulate myxospores throughout their lives. However, opportunistic observations that wild-caught seatrout cleared infection when maintained in aquaculture conditions and evidence of encapsulated infected necrotic myofibers suggested that fish develop an immunity against this parasite, or that myxospores have a limited life span. To evaluate myxospore clearance and to test putative resistance to re-infection, we examined 44 wild-caught seatrout broodstock maintained in parasite-free water for 2-6 yr. Twenty-five fish served as negative controls (time zero of experiment), and 19 were exposed to water-borne K. inornata infective stages for 18 wk. Over 73% of the exposed fish became infected, compared to ~12% of control fish, indicating that fish were susceptible to re-infection by K. inornata. Whether plasmodia degenerate because K. inornata myxospores have a limited life span or seatrout develop an adaptive immunity against these life stages remains unknown. To test for accumulation of myxospores over time, we compared myxospore densities and intensities between sexes and across ages and sizes of wild seatrout. There was no significant difference in myxospore densities with size, age, or sex. However, intensities increased significantly with increasing fish age and size, indicating accrual of myxospores over time. These results combined with evidence of infection clearance suggest that K. inornata myxospores do not persist but nevertheless accrue in wild seatrout due to continuous contact with infective stages.


Assuntos
Cnidários , Doenças dos Peixes , Myxozoa , Perciformes , Animais , Doenças dos Peixes/parasitologia , Perciformes/parasitologia , Reinfecção/veterinária , Truta , Água
19.
Parasit Vectors ; 15(1): 322, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36088326

RESUMO

BACKGROUND: Sparicotylosis is an enzootic parasitic disease that is well established across the Mediterranean Sea. It is caused by the polyopisthocotylean monogenean Sparicotyle chrysophrii and affects the gills of gilthead sea bream (GSB; Sparus aurata). Current disease management, mitigation and treatment strategies are limited against sparicotylosis. To successfully develop more efficient therapeutic strategies against this disease, understanding which molecular mechanisms and metabolic pathways are altered in the host is critical. This study aims to elucidate how S. chrysophrii infection modulates the plasma proteome of GSB and to identify the main altered biological processes involved. METHODS: Experimental infections were conducted in a recirculating aquaculture system (RAS) in which naïve recipient GSB ([R]; 70 g; n = 50) were exposed to effluent water from S. chrysophrii-infected GSB (98 g; n = 50). An additional tank containing unexposed naïve fish (control [C]; 70 g; n = 50) was maintained in parallel, but with the open water flow disconnected from the RAS. Haematological and infection parameters from sampled C and R fish were recorded for 10 weeks. Plasma samples from R fish were categorised into three different groups according to their infection intensity, which was based on the number of worms fish-1: low (L: 1-50), medium (51-100) and high (H: > 100). Five plasma samples from each category and five C samples were selected and subjected to a SWATH-MS proteome analysis. Additional assays on haemoglobin, cholesterol and the lytic activity of the alternative complement pathway were performed to validate the proteome analysis findings. RESULTS: The discriminant analysis of plasma protein abundance revealed a clear separation into three groups (H, M/L and C). A pathway analysis was performed with the differentially quantified proteins, indicating that the parasitic infection mainly affected pathways related to haemostasis, the immune system and lipid metabolism and transport. Twenty-two proteins were significantly correlated with infection intensity, highlighting the importance of apolipoproteins, globins and complement component 3. Validation assays of blood and plasma (haemoglobin, cholesterol and lytic activity of alternative complement pathway) confirmed these correlations. CONCLUSIONS: Sparicotylosis profoundly alters the haemostasis, the innate immune system and the lipid metabolism and transport in GSB. This study gives a crucial global overview of the pathogenesis of sparicotylosis and highlights new targets for further research.


Assuntos
Dourada , Trematódeos , Animais , Hemoglobinas , Proteoma , Proteômica , Dourada/parasitologia , Água
20.
J Parasitol ; 108(5): 419-422, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36098751

RESUMO

Texas quail populations have declined over the past few decades. While habitat loss has been identified as the primary cause, it has been speculated that pathogens may also play a role in this decline. To help address this, we collected scaled quail, Callipepla squamata, Gambel's quail, Callipepla gambelii, and Montezuma quail, Cyrtonyx montezumae, from across the Trans-Pecos ecoregion of Texas via hunter-harvest. Quail samples were then necropsied to document pathogens not previously recorded in the host species. Pathogens were submitted to the Texas A&M University Veterinary Medicine Diagnostic Lab (TVMDL), where parasite identification and histopathological analyses were conducted. From this, we identified several parasites that had never been documented in the quails of the Trans-Pecos ecoregion of Texas. This study was the first to document Mycobacterium sp. and Sarcocystis sp. in scaled quail, Subulura sp. and Physaloptera sp. in Montezuma quail, and Oxyspirura petrowi and Aulonocephalus pennula in a Texas Gambel's quail.


Assuntos
Ascaridídios , Doenças das Aves , Galliformes , Thelazioidea , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/parasitologia , Humanos , Codorniz/parasitologia
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