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1.
Eur J Protistol ; 78: 125770, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33549968

RESUMO

Two strains of Sphaerodinium were established from two mountain areas in Portugal and examined by light microscopy, scanning and transmission electron microscopy, and sequence analyses of nuclear-encoded SSU, ITS1-5.8S-ITS2 and LSU rDNA. Both strains were identified as S. polonicum var. tatricum on the basis of comparison with the original taxonomic descriptions within the genus. The two strains were nearly identical in morphology and ultrastructure, except for the presence of pseudograna-like thylakoid stacks within more rounded chloroplast lobes in one of them. Sexual reproduction occurred in culture batches and resting cysts with single or grouped processes with wide bases and distal platforms with slightly recurved margins were seen to develop by sudden retraction of planozygote cytoplasm. Morphological, fine-structural and molecular characters were compared with previously available information from S. cracoviense, allowing for a more robust characterization of the genus. Important characters include a type F eyespot, a pusule canal linking the transverse flagellar canal to a collecting chamber connected to regular pusular tubes, a ventral fibre extending from the proximal-right side of the longitudinal basal body, and a membranous, lamellar body with a honeycomb pattern near the flagellar base area. The latter two features are shared with Baldinia anauniensis.


Assuntos
Dinoflagelados/classificação , Dinoflagelados/ultraestrutura , Filogenia , DNA de Protozoário/genética , DNA Ribossômico/genética , Dinoflagelados/genética , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão
2.
Eur J Protistol ; 78: 125769, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33549969

RESUMO

A little-known haptorid ciliate, Helicoprorodon multinucleatum Dragesco, 1960, was found in a sandy beach at Qingdao, China. Its morphology was studied based on microscopic observations of live and protargol-stained specimens and morphometrics, and the phylogeny was analyzed using SSU rRNA gene sequences. Helicoprorodon multinucleatum is characterized by the combination of the following features: (i) a very narrowly worm-like body with a size of about 300-1500 µm × 30-60 µm in vivo, and two circles of horn-like protuberances around the head; (ii) 50-160 spherical macronuclear nodules scattered throughout the body; (iii) rod-shaped, 10-50 µm long extrusomes gathered into several bunches, which are randomly distributed beneath pellicle; and (iv) 42-88 somatic kineties, including four oralized kineties and two dorsal brush rows. Phylogenetic analyses reveal that both the family Helicoprorodontidae and the genus Helicoprorodon might be monophyletic. In addition, we provide an illustrated key to the species and the geographical distribution of the genus Helicoprorodon.


Assuntos
Cilióforos/classificação , Filogenia , China , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
3.
Eur J Protistol ; 78: 125768, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33549970

RESUMO

In a study of marine ciliate diversity, we collected an Anteholosticha monilata-like population from Vietnam. To identify this population, we analyzed its morphology, some morphogenetic stages, and molecular phylogeny. Based on these data, we conclude that the Vietnamese population is new to science. Anteholosticha foissneri n. sp. resembles Anteholosticha monilata-like species considering (1) the number and arrangement of macronuclear nodules and micronuclei; (2) the presence of cortical granules; and (3) the saline habitat. However, the new species can be easily distinguished from these species by the arrangement, color, and shape of the cortical granules. The divisional morphogenesis commences with the de novo proliferation of basal bodies as a single longitudinal patch left of the posteriormost midventral cirral pair. This character state has not been reported before in Anteholosticha (based on check of the available data) and probably reflects a distinct clade within the nuclear small subunit ribosomal RNA gene tree.


Assuntos
Cilióforos/classificação , Morfogênese , Filogenia , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie , Vietnã
4.
Eur J Protistol ; 78: 125767, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33639326

RESUMO

The peritrich genus Epistylis is speciose, however many species lack complete morphological description based on modern criteria and/or molecular data. In the present study, one new species, i.e., E. foissneri n. sp., and two morphologically similar species, i.e., E. hentscheli Kahl, 1935 and E. vaginula Stokes, 1884, collected from freshwater habitats in China, were studied. Epistylis foissneri n. sp. is characterized by its extremely slender zooids encased in a gelatinous sheath, symmetrically dichotomously branched stalk, trochal band located at mid-body, contractile vacuole located on dorsal wall of infundibulum, infundibular polykinety 3 (P3) composed of three equal-length rows that terminate above infundibular polykinety 1 (P1), 105-110 silverlines between the peristome and the trochal band, and about 110 silverlines between the trochal band and the scopula. Epistylis hentscheli is characterized by its asymmetric pyriform zooids (average length ca. 160 µm in vivo), dichotomously branched stalk with transverse striations on the surface of the upper portion, P3 three-rowed and terminating slightly above P1, 60-75 silverlines between the peristome and the trochal band, and 55-90 silverlines between the trochal band and the scopula. Epistylis vaginula is characterized by its elongated body shape (about 100 µm in length in vivo), dichotomously branched and smooth stalk, P3 three-rowed and terminating above P1, 80-100 silverlines between the peristome and the trochal band, and 45-80 silverlines between the trochal band and the scopula. The small subunit ribosomal DNA gene (SSU rDNA) of these three species was sequenced and supported the validity of each. Phylogenetic analyses based on SSU rDNA sequence data revealed that all three morphospecies group with other congeners within the major clade of Epistylis.


Assuntos
Água Doce , Oligoimenóforos/classificação , Filogenia , China , DNA de Protozoário/genética , Água Doce/parasitologia , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
5.
Anal Chem ; 93(4): 2097-2105, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33464825

RESUMO

In many countries targeting malaria elimination, persistent malaria infections can have parasite loads significantly below the lower limit of detection (LLOD) of standard diagnostic techniques, making them difficult to identify and treat. The most sensitive diagnostic methods involve amplification and detection of Plasmodium DNA by polymerase chain reaction (PCR), which requires expensive thermal cycling equipment and is difficult to deploy in resource-limited settings. Isothermal DNA amplification assays have been developed, but they require complex primer design, resulting in high nonspecific amplification, and show a decrease in sensitivity than PCR methods. Here, we have used a computational approach to design a novel isothermal amplification assay with a simple primer design to amplify P. falciparum DNA with analytical sensitivity comparable to PCR. We have identified short DNA sequences repeated throughout the parasite genome to be used as primers for DNA amplification and demonstrated that these primers can be used, without modification, to isothermally amplify P. falciparum parasite DNA via strand displacement amplification. Our novel assay shows a LLOD of ∼1 parasite/µL within a 30 min amplification time. The assay was demonstrated with clinical samples using patient blood and saliva. We further characterized the assay using direct amplicon next-generation sequencing and modified the assay to work with a visual readout. The technique developed here achieves similar analytical sensitivity to current gold standard PCR assays requiring a fraction of time and resources for PCR. This highly sensitive isothermal assay can be more easily adapted to field settings, making it a potentially useful tool for malaria elimination.


Assuntos
DNA de Protozoário/genética , Malária Falciparum/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , Plasmodium falciparum/genética , Sequências Repetitivas de Ácido Nucleico/genética , DNA de Protozoário/isolamento & purificação , Humanos , Limite de Detecção , Plasmodium falciparum/isolamento & purificação , Reprodutibilidade dos Testes
6.
PLoS One ; 15(12): e0243087, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33326418

RESUMO

Because more than 80% of species of gamete-spawning corals, including most Acroporidae species, do not inherit Symbiodiniaceae from their parents, they must acquire symbiont cells from sources in their environment. To determine whether photosynthetically competent Symbiodiniaceae expelled as fecal pellets from giant clams are capable of colonizing corals, we conducted laboratory experiments in which planula larvae of Acropora tenuis were inoculated with the cells in fecal pellets obtained from Tridacna crocea. T. crocea fecal pellets were administered once a day, and three days later, cells of Symbiodiniaceae from the fecal pellets had been taken up by the coral larvae. T. crocea fecal pellets were not supplied from the 4th day until the 8th day, and the cell densities in the larvae increased until the 8th day, which indicated the successful colonization by Symbiodiniaceae. The control group exhibited the highest mean percentage of larvae (100%) that were successfully colonized by culture strains of Symbiodiniaceae, and larvae inoculated with fecal pellets reached a colonization percentage of 66.7 ~ 96.7% on the 8th day. The highest colonization rate was achieved with the fecal pellets containing cells with high photosynthetic competency (Fv/Fm). Interestingly, the genetic composition of Symbiodiniaceae in the larvae retrieved on the 8th day differed from that in the fecal pellets and showed exclusive domination of the genus Symbiodinium. A minor but significant population of the genus Cladocopium in the fecal pellets was not inherited by the larvae. These experiments provided the first demonstration that the Symbiodiniaceae from tridacnine clams provided via fecal pellets can colonize and even proliferate in coral larvae.


Assuntos
Alveolados/isolamento & purificação , Antozoários/parasitologia , Bivalves/parasitologia , Alveolados/classificação , Alveolados/genética , Animais , Recifes de Corais , DNA de Protozoário/genética , Fezes/parasitologia , Fotossíntese , Análise de Sequência de DNA , Simbiose
7.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(6): 612-617, 2020 Jun 30.
Artigo em Chinês | MEDLINE | ID: mdl-33325196

RESUMO

OBJECTIVE: To investigate the drug-resistant gene polymorphisms in Plasmodium falciparum imported from Equatorial Guinea to Shandong Province. METHODS: From 2015 to 2016, blood samples were collected from imported P. falciparum malaria patients returning from Equatorial Guinea to Shandong Province, and genome DNA of the malaria parasite was extracted. The drug-resistant Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and K13 genes of P. falciparum were amplified using a PCR assay, followed by DNA sequencing, and the sequences were aligned. RESULTS: The target fragments of all 5 drug-resistant genes of P. falciparum were successfully amplified and sequenced. There were 72.8%, 18.6%, and 8.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfcrt gene, respectively, and all mutant haplotypes were CVIET (the underline indicates the mutation site). There were 20.0%, 61.4% and 18.6% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfmdr1 gene, respectively, and the mutant haplotypes mainly included YF and NF (the underlines indicate the mutation sites). There were 1.4%, 98.6%, and 0 of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhfr gene, respectively, and AIRNI was the predominant mutant haplotype (the underline indicates the mutation site). There were 1.4%, 94.3%, and 4.3% of P. falciparum parasites carrying the wild-, mutant-, and mixed-type Pfdhps gene, respectively, and SGKAA was the predominant mutant haplotype (the underline indicates the mutation site). The complete drug-resistant IRNGE genotype consisted of 8.6% of the Pfdhfr and Pfdhps genes, and the K13 gene A578S mutation occurred in 1.4% of the parasite samples. CONCLUSIONS: There are mutations in the Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, and K13 genes of P. falciparum imported from Equatorial Guinea to Shandong Province, with a low frequency in the Pfcrt gene mutation and a high frequency in the Pfmdr1, Pfdhfr, and Pfdhps gene mutations, and the K13 gene A578S mutation is detected in the parasite samples.


Assuntos
Antimaláricos , Resistência a Medicamentos/genética , Malária Falciparum , Plasmodium falciparum/genética , Proteínas de Protozoários , Antimaláricos/uso terapêutico , China/epidemiologia , DNA de Protozoário/genética , Guiné Equatorial/epidemiologia , Genótipo , Humanos , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Mutação , Plasmodium falciparum/efeitos dos fármacos , Polimorfismo Genético/efeitos dos fármacos , Proteínas de Protozoários/genética
8.
Rev Soc Bras Med Trop ; 54: e00472020, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33338104

RESUMO

INTRODUCTION: The objective of this study was to evaluate the performance of filter paper (FP) for lesion scraping collection in a polymerase chain reaction (PCR) for cutaneous leishmaniasis (CL) diagnosis. METHODS: Lesion scrapings from 48 patients were collected and analyzed for PCR. RESULTS: PCR with FP detected up to three Leishmania braziliensis promastigotes. Considering the direct search by microscopy or PCR of samples collected in STE buffer as standards, the sensitivity of PCR with FP was 100%. CONCLUSIONS: FP can be useful for CL diagnosis in remote regions, allowing high sensitivity in the detection of the parasite by PCR.


Assuntos
Leishmania braziliensis , Leishmaniose Cutânea , DNA de Protozoário/genética , Humanos , Leishmania braziliensis/genética , Leishmaniose Cutânea/diagnóstico , Microscopia , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade
9.
Parasitol Res ; 119(11): 3739-3753, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33000433

RESUMO

Many tick-borne pathogens (TBPs) are present in wildlife. The objective of this study is to reveal the role of wild bears in maintaining TBPs. A total of 49 brown bears (Ursus arctos yesoensis) from Hokkaido, and 18 Japanese black bears (Ursus thibetanus japonicus) from Tochigi, and 66 Japanese black bears from Nagano were examined by two molecular methods, reverse line blot (RLB) hybridization, and nested PCR. A total of 5 TBPs (Hepatozoon ursi, Babesia sp. UR2-like group, Cytauxzoon sp. UR1, Babesia sp. UR1, and Babesia microti) were detected from bear blood DNA samples. B. microti was detected from blood DNA samples of Japanese black bear for the first time, with the prevalence of 6.0% (5/84). Out of detected pathogens, H. ursi, Babesia sp. UR2-like pathogens, and Cytauxzoon sp. UR1 were considered as three of the most prevalent TBPs in bears. The prevalence of H. ursi were significantly higher in Japanese black bear (0% vs 96.4%) while that of Babesia sp. UR2-like group was higher in Hokkaido brown bears (89.8% vs 40.5%). The prevalence of Babesia sp. UR1 were significantly higher in Japanese black bears from Tochigi (44.4%), comparing with those from Nagano (18.2%). The prevalence of the detected TBPs were significantly higher in adult bears, comparing with those in younger bears. The present study suggests that Japanese bear species contribute in the transmission of several TBPs in Japan. The expanding distribution of bears might cause the accidental transmission of TBPs to humans and domestic animals.


Assuntos
Apicomplexa/isolamento & purificação , Infecções Protozoárias em Animais/parasitologia , Ursidae/parasitologia , Animais , Animais Selvagens/parasitologia , Apicomplexa/classificação , Apicomplexa/genética , DNA de Protozoário/genética , Japão/epidemiologia , Prevalência , Infecções Protozoárias em Animais/epidemiologia , Infecções Protozoárias em Animais/transmissão , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/parasitologia , Doenças Transmitidas por Carrapatos/transmissão , Carrapatos/parasitologia
10.
Exp Appl Acarol ; 82(3): 411-429, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33009646

RESUMO

Ticks are hematophagous ectoparasites that have a significant impact on their animal hosts. Along with mosquitoes, they are the main arthropod vectors of disease agents in domestic animals, wildlife and humans. To investigate the occurrence and prevalence of piroplasmids in ticks, DNA was extracted from 519 hard ticks collected from 116 hunted Hokkaido sika deer (Cervus nippon yesoensis). The success of the DNA extraction was confirmed by touchdown PCR targeting the mitochondrial 16S rDNA gene of ticks. Touchdown PCR and reverse line blot (RLB) hybridization targeting the 18S rRNA gene were used to detect 14 piroplasm species. All hard ticks parasitizing Hokkaido sika deer were identified as belonging to the genera Ixodes and Haemaphysalis. In total 163 samples (31.4%) were positive for Babesia and Theileria spp. among tick species according to RLB hybridization. Tick DNA hybridized to the oligonucleotide probes of Theileria sp. Thrivae (27.0% of ticks; 140/519), Theileria capreoli (10.6%; 55/519), Babesia divergens-like (1.7%; 9/519), Babesia sp. (Bab-SD) (0.6%; 3/519), Babesia microti U.S. (0.4%; 2/519), and B. microti Hobetsu (0.4%; 2/519). The partial sequencing and phylogenetic analyses of the 18S rRNA gene confirmed the RLB hybridization results. Further investigations are needed to reveal the epidemiology and respective vectors of these pathogens.


Assuntos
Babesia , Cervos/parasitologia , Ixodidae/parasitologia , Theileria , Animais , Babesia/genética , Babesiose/transmissão , DNA de Protozoário/genética , Japão/epidemiologia , Mosquitos Vetores , Filogenia , RNA Ribossômico 18S/genética , Theileria/genética , Theileriose/transmissão
11.
Parasitol Res ; 119(11): 3763-3770, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32909143

RESUMO

Balantioides coli is the only known zoonotic ciliate that can infect humans and is usually acquired from swine. It has, however, been reported in other mammals, including guinea pigs, where infection prevalence and molecular characterization are relatively unknown. In the present study, 32 guinea pigs from two different pet markets in Luoyang city of the Henan province in China were evaluated for ciliate-like trophozoites or cysts by direct fecal smear microscopy. Positive samples were further characterized using 18S rDNA and ITS1-5.8S rDNA-ITS2 sequence analysis. Microscopy indicated that ciliate-like cysts were observed in the fecal samples of several guinea pigs, were spherical in shape, and exhibited sizes of 40-65 µm in diameter. The average cyst-positive prevalence in guinea pigs was 62.5%. Sequence analysis indicated that the guinea pig-derived ciliate isolates belonged to B. coli and included two genetic variants (A and B), of which genetic variant A was more dominant among the guinea pig samples. To the best of our knowledge, the present study is the first molecular identification of B. coli in guinea pigs and provides some important information for investigating the molecular epidemiology of B. coli.


Assuntos
Balantidíase/veterinária , Cobaias/parasitologia , Animais de Estimação/parasitologia , Doenças dos Roedores/parasitologia , Trichostomatina/isolamento & purificação , Animais , Balantidíase/epidemiologia , Balantidíase/parasitologia , China/epidemiologia , DNA de Protozoário/genética , DNA Ribossômico/genética , Fezes/parasitologia , Filogenia , Prevalência , Doenças dos Roedores/epidemiologia , Trichostomatina/citologia , Trichostomatina/genética
12.
BMC Infect Dis ; 20(1): 671, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32933490

RESUMO

BACKGROUND: The increasing antimalarial drug resistance is a significant hindrance to malaria control and elimination programs. For the last six decades, chloroquine (CQ) plus pyrimethamine remains the first-line treatment for P. vivax malaria. Regions where both P. falciparum and P. vivax co-exist, P. vivax is exposed to antifolate drugs due to either misdiagnosis or improper treatment that causes selective drug pressure to evolve. Therefore, the present study aims to estimate antimalarial drug resistance among the complicated and uncomplicated P. vivax patients. METHODS: A total of 143 P. vivax malaria positive patients were enrolled in this study, and DNA was isolated from their blood samples. Pvcrt-o, Pvmdr-1, Pvdhps, and Pvdhfr genes were PCRs amplified, and drug resistance-associated gene mutations were analyzed. Statistical analysis of the drug resistance genes and population diversity was performed using MEGA vs. 7.0.21 and DnaSP v software. RESULTS: Among the CQ resistance marker gene Pvcrt-o, the prevalence of K10 insertion was 17.5% (7/40) and 9.5% (7/73) of complicated and uncomplicated P vivax group isolates respectively. In Pvmdr-1, double mutant haplotype (M958/L1076) was found in 99% of the clinical isolates. Among the pyrimethamine resistance-associated gene Pvdhfr, the double mutant haplotype I13P33F57R58T61N117I173 was detected in 23% (11/48) in complicated and 20% (17/85) in uncomplicated group isolates. In the sulphadoxine resistance-associated Pvdhps gene, limited polymorphism was observed with the presence of a single mutant (D459A) among 16 and 5% of the clinical isolates in the complicated and uncomplicated group respectively. CONCLUSION: The study presents the situations of polymorphism in the antimalarial drug resistance-associated genes and emphasizes the need for regular surveillance. It is imperative for the development of suitable antimalarial drug policy in India.


Assuntos
Antimaláricos/uso terapêutico , Resistência a Medicamentos/genética , Malária Vivax/tratamento farmacológico , Plasmodium vivax/genética , Proteínas de Protozoários/genética , Adolescente , Criança , Pré-Escolar , Cloroquina/uso terapêutico , DNA de Protozoário/genética , DNA de Protozoário/metabolismo , Feminino , Antagonistas do Ácido Fólico/uso terapêutico , Haplótipos , Humanos , Índia , Masculino , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Plasmodium vivax/isolamento & purificação , Polimorfismo de Nucleotídeo Único , Adulto Jovem
13.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(4): 345-349, 2020 Mar 31.
Artigo em Chinês | MEDLINE | ID: mdl-32935506

RESUMO

OBJECTIVE: To establish a novel nucleic acid assay for detection of Giardia lamblia based on the recombinase-aided isothermal amplification (RAA) assay, and evaluate its sensitivity and specificity for detection of G. lamblia. METHODS: The specific primer sequences and florescent probes were designed and synthesized based on the G. lamblia ß-giardin gene as the target gene, and a fluorescent RAA assay was established. The recombinant plasmids at various copies (containing the ß-giardin gene target sequence) and the genomic DNA of G. lamblia at various concentrations were used as templates for the fluorescent RAA assay to assess the sensitivity, and the genomic DNA from G. lamblia, Schistosoma japonicum, Clonorchis sinensis, Cryptosporidium parvum, Ascaris lumbricoides, Salmonella and Shigella was used as templates to assess the specificity of the fluorescent RAA assay. RESULTS: A novel fluorescent RAA assay was successfully established for detection of G. lamblia, which allowed the rapid and specific amplification of the target gene fragments at 39 ℃ within 20 min. The sensitivities of the fluorescent RAA assay were 102 copies/µL and 1 pg/µL for detection of the recombinant plasmid and G. lamblia genomic DNA, respectively, and the fluorescent RAA assay was negative for detection of the genomic DNA from S. japonicum, C. sinensis, C. parvum, A. lumbricoides, Salmonella and Shigella, which showed a high specificity. CONCLUSIONS: A fluorescent RAA assay, which is simple, sensitive and specific, is successfully established for nucleic acid detection of G. lamblia.


Assuntos
DNA de Protozoário , Giardia lamblia , Giardíase , Técnicas de Amplificação de Ácido Nucleico , Parasitologia , Animais , DNA de Protozoário/genética , Giardia lamblia/genética , Giardíase/diagnóstico , Giardíase/parasitologia , Parasitologia/métodos , Recombinases , Sensibilidade e Especificidade
14.
Protist ; 171(4): 125751, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32890795

RESUMO

With highly specialized morphology and unexplored functional capacities, ciliates from extreme habitats are drawing increasing attention. During a microbial investigation of a solar saltern pond (salinity 240‰) on Mallorca, Spain, a previously unknown scuticociliate, Platynematum rossellomorai n. sp. was isolated, cultured and studied using a tripartite approach consisting of a morphological description, a molecular analysis and an ecophysiological characterization. The ciliate has distinct morphological characteristics and its main diagnostic features include a large anteriorly positioned oral area (occupying almost half of the body length), two caudal cilia and a small number of somatic kineties. However, due to the most important generic feature of Cinetochilidae, the consistency of the arrangement of the adoral membranes, the ciliate is classified as a new member of the genus Platynematum. Its 18S rRNA gene sequence shows a sequence similarity of 91.0% to the closest deposited relative, Platynematum salinarum, and a phylogenetic analysis reveals a close relationship to other members of the family Cinetochilidae Perty, 1852. Growth experiments identify the ciliate as a borderline halophile, with a tolerance range between 180 and 280‰ salinity. The ciliate apparently accumulates the compatible solutes glycine betaine and ectoine to counterbalance osmotic stress, however, other osmoregulatory mechanisms are not excluded.


Assuntos
Oligoimenóforos/classificação , Filogenia , Tanques/parasitologia , DNA de Protozoário/genética , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Espanha , Especificidade da Espécie
15.
Parasitol Res ; 119(11): 3755-3761, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32918603

RESUMO

Free-living amoeba (FLA) research in the Philippines is still in its infancy but has, by far, demonstrated the presence of potentially pathogenic species. Acanthamoeba may cause sight-threatening and central nervous system infections to humans, yet its epidemiologic distribution from local environmental sources is yet to be defined. The present study aimed to provide a baseline epidemiologic distribution of Acanthamoeba spp. in freshwater systems in the Philippines and establish potential pathogenicity of isolates through thermo-tolerance assay. A total of 63 water samples were collected from 13 freshwater systems all over the Philippine archipelago. The low-volume (50 ml) water samples were processed and cultured on non-nutrient agar lawned with Escherichia coli and observed for amoebic growth using light microscopy. Amoebic culture demonstrated 14.28% (9/63) positivity while further molecular testing of culture-positive plates using Acanthamoeba-specific primers demonstrated 100% (9/9) confirmation of Acanthamoeba species. Genotyping of Acanthamoeba isolates revealed T1, T3, T4, T5, T7, T11, and T15 genotypes. Thermo-tolerance assay demonstrated that T5 and T7 genotypes were potentially pathogenic strains. The evidence of environmental distribution of Acanthamoeba spp. in the freshwater systems in the Philippines and thermo-tolerance profile of isolates are significant aspects of amoeba study in public health and calls for initiatives in the dissemination of relevant information and the expansion of knowledge, awareness, and policies on pathogenic waterborne amoeba to mitigate, prevent, detect, and report cases of human infections.


Assuntos
Acanthamoeba/isolamento & purificação , Acanthamoeba/fisiologia , Água Doce/parasitologia , Acanthamoeba/genética , Acanthamoeba/crescimento & desenvolvimento , DNA de Protozoário/genética , Monitoramento Ambiental , Genótipo , Humanos , Filipinas , Termotolerância
16.
PLoS Negl Trop Dis ; 14(9): e0008684, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32946436

RESUMO

Leishmania tropica is one of the main causative agents of cutaneous leishmaniasis (CL). Population structures of L. tropica appear to be genetically highly diverse. However, the relationship between L. tropica strains genomic diversity, protein coding gene evolution and biogeography are still poorly understood. In this study, we sequenced the genomes of three new clinical L. tropica isolates, two derived from a recent outbreak of CL in camps hosting Syrian refugees in Lebanon and one historical isolate from Azerbaijan to further refine comparative genome analyses. In silico multilocus microsatellite typing (MLMT) was performed to integrate the current diversity of genome sequence data in the wider available MLMT genetic population framework. Single nucleotide polymorphism (SNPs), gene copy number variations (CNVs) and chromosome ploidy were investigated across the available 18 L. tropica genomes with a main focus on protein coding genes. MLMT divided the strains in three populations that broadly correlated with their geographical distribution but not populations defined by SNPs. Unique SNPs profiles divided the 18 strains into five populations based on principal component analysis. Gene ontology enrichment analysis of the protein coding genes with population specific SNPs profiles revealed various biological processes, including iron acquisition, sterols synthesis and drug resistance. This study further highlights the complex links between L. tropica important genomic heterogeneity and the parasite broad geographic distribution. Unique sequence features in protein coding genes identified in distinct populations reveal potential novel markers that could be exploited for the development of more accurate typing schemes to further improve our knowledge of the evolution and epidemiology of the parasite as well as highlighting protein variants of potential functional importance underlying L. tropica specific biology.


Assuntos
Variação Genética , Genoma de Protozoário , Leishmania tropica/genética , Azerbaijão , Variações do Número de Cópias de DNA , DNA de Protozoário/genética , Dosagem de Genes , Mapeamento Geográfico , Humanos , Líbano , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Repetições de Microssatélites , Filogenia , Polimorfismo de Nucleotídeo Único , Refugiados , Síria
17.
PLoS Pathog ; 16(8): e1008772, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866214

RESUMO

The tick-borne apicomplexan parasite, Babesia bovis, a highly persistent bovine pathogen, expresses VESA1 proteins on the infected erythrocyte surface to mediate cytoadhesion. The cytoadhesion ligand, VESA1, which protects the parasite from splenic passage, is itself protected from a host immune response by rapid antigenic variation. B. bovis relies upon segmental gene conversion (SGC) as a major mechanism to vary VESA1 structure. Gene conversion has been considered a form of homologous recombination (HR), a process for which Rad51 proteins are considered pivotal components. This could make BbRad51 a choice target for development of inhibitors that both interfere with parasite genome integrity and disrupt HR-dependent antigenic variation. Previously, we knocked out the Bbrad51 gene from the B. bovis haploid genome, resulting in a phenotype of sensitivity to methylmethane sulfonate (MMS) and apparent loss of HR-dependent integration of exogenous DNA. In a further characterization of BbRad51, we demonstrate here that ΔBbrad51 parasites are not more sensitive than wild-type to DNA damage induced by γ-irradiation, and repair their genome with similar kinetics. To assess the need for BbRad51 in SGC, RT-PCR was used to observe alterations to a highly variant region of ves1α transcripts over time. Mapping of these amplicons to the genome revealed a significant reduction of in situ transcriptional switching (isTS) among ves loci, but not cessation. By combining existing pipelines for analysis of the amplicons, we demonstrate that SGC continues unabated in ΔBbrad51 parasites, albeit at an overall reduced rate, and a reduction in SGC tract lengths was observed. By contrast, no differences were observed in the lengths of homologous sequences at which recombination occurred. These results indicate that, whereas BbRad51 is not essential to babesial antigenic variation, it influences epigenetic control of ves loci, and its absence significantly reduces successful variation. These results necessitate a reconsideration of the likely enzymatic mechanism(s) underlying SGC and suggest the existence of additional targets for development of small molecule inhibitors.


Assuntos
Antígenos de Protozoários , Babesia bovis , Conversão Gênica/imunologia , Genoma de Protozoário/imunologia , Proteínas de Protozoários , Rad51 Recombinase , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Babesia bovis/genética , Babesia bovis/imunologia , DNA de Protozoário/genética , DNA de Protozoário/imunologia , Haploidia , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Rad51 Recombinase/genética , Rad51 Recombinase/imunologia
18.
Parasitol Res ; 119(10): 3469-3479, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32827104

RESUMO

Amphibians are among the most threatened vertebrate groups in the world, and the main causes include climate change, habitat destruction, and emerging diseases. Herein, we investigated the occurrence and characterized molecularly Apicomplexa in anurans from southeastern Brazil. Forty individuals from seven anuran species were sampled in São Paulo state. In the molecular analyses, one Leptodactylus latrans and one Rhinella diptycha were positive in PCR assays for species of Hepatozoon. Two L. latrans were also positive for coccidian infections (Lankesterella sp. and an unidentified coccidian species). Phylogenetic analysis based on 18S rDNA clustered the sequences detected in anurans from the present study with Hepatozoon spp. detected in reptiles and other anurans from Brazil, albeit they were separate from Hepatozoon haplotypes detected in frogs from Africa and North America. Our study showed, for the first time, the molecular detection of Lankesterella sp. and another coccidian in L. latrans. Additionally, co-infection by different species of Hepatozoon haplotypes and an unidentified coccidian in anurans from Brazil was documented.


Assuntos
Anuros/parasitologia , Apicomplexa/genética , Apicomplexa/isolamento & purificação , Infecções Protozoárias em Animais/parasitologia , Animais , Anuros/classificação , Apicomplexa/classificação , Brasil/epidemiologia , Coccídios/classificação , Coccídios/genética , Coccídios/isolamento & purificação , Coccidiose/epidemiologia , Coccidiose/parasitologia , Coccidiose/veterinária , DNA de Protozoário/genética , DNA Ribossômico/genética , Filogenia , Infecções Protozoárias em Animais/epidemiologia
19.
Parasitol Res ; 119(10): 3541-3548, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32803333

RESUMO

The aim of this study was to evaluate, through qPCR, the prevalence of parasitemia in sick kennel dogs naturally infected by canine leishmaniasis. An evaluation of daily changes of the parasitic load in peripheral blood was also performed. A comprehensive clinical examination and the collection of several samples (blood, lymph node, skin, and conjunctiva) were performed in 140 dogs living in an endemic area. Among these, only the dogs with clinically evident leishmaniasis were enrolled (39/140; 27.9%). Twelve (30.8%) out of 39 showed parasitemia, with a low load (median: 4 Leishmania/ml) despite a high lymph node parasite load (median: 4000 Leishmania/ml) and high IFAT titers (≥ 1:640). Seven sick dogs were sampled every 4 h for 6 times during a 24-h period, in order to obtain light- and dark-span samples. Only one (14.3%) out of the seven serial sampled dogs showed Leishmania DNA in the peripheral blood in two samples (2/42; 4.8%). Surprisingly, Leishmania DNA was also detected in the peripheral blood of asymptomatic dogs, negative to both serology and PCR performed on samples other than blood (6/101; 5.9%). The present study confirms that in canine leishmaniasis parasitemia is uncommon and even transitory. Even if recommended, microscopic examination is confirmed as a low sensitivity method with a lower diagnostic utility in canine leishmaniasis than qPCR. Moreover, circulating Leishmania DNA can be found even in healthy dogs. This finding is important in clinical practice because in endemic areas it suggests a transfusion risk and a possible transmission to the vector.


Assuntos
Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Parasitemia/veterinária , Animais , DNA de Protozoário/sangue , DNA de Protozoário/genética , Doenças do Cão/epidemiologia , Cães , Leishmania infantum/genética , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Carga Parasitária/veterinária , Parasitemia/epidemiologia , Parasitemia/parasitologia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real/veterinária
20.
Parasitol Res ; 119(11): 3729-3737, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32779020

RESUMO

A new Eimeria species is described from a common bronzewing pigeon (Phaps chalcoptera) (Latham, 1790) in Western Australia. Sporulated oocysts of Eimeria chalcoptereae n. sp. (n = 30) are subspheroidal, 22-25 × 21-24 (23.5 × 22.6) µm; length/width (L/W) ratio 1.0-1.1 (1.04) µm. Wall bi-layered, 1.0-1.4 (1.2) µm thick, outer layer smooth, c.2/3 of total thickness. Micropyle barely discernible. Oocyst residuum is absent, but 2 to 3 small polar granules are present. Sporocysts (n = 30) ellipsoidal, 13-14 × 7-8 (13.5 × 7.2) µm; L/W ratio 1.8-2.0 (1.88). Stieda body present, flattened to half-moon-shaped, 0.5 × 2.0 µm; sub-Stieda present, rounded to trapezoidal, 1.5 × 2.5 µm; para-Stieda body absent; sporocyst residuum present, usually as an irregular body consisting of numerous small granules that appear to be membrane-bound. Sporozoites vermiform, with a robust refractile body and centrally located nucleus. Isolated Eimeria oocysts were analysed at the 18S and 28S ribosomal RNA and the mitochondrial cytochrome oxidase (COI) loci. Analyses revealed that Eimeria chalcoptereae n. sp. shared the highest number of molecular features with an Eimeria sp. previously identified from a domestic pigeon in Australia (KT305927-29), with similarities at these three loci of 98.53%, 97.32% and 94.93%, respectively. According to morphological and molecular analysis, the isolated coccidian parasite is a new species of Eimeria named Eimeria chalcoptereae n. sp. after its host, the common bronzewing pigeon (Phaps chalcoptera) (Columbiformes: Columbidae) (Latham, 1790).


Assuntos
Doenças das Aves/parasitologia , Coccidiose/veterinária , Columbidae/parasitologia , Eimeria/citologia , Eimeria/genética , Animais , Coccidiose/parasitologia , DNA de Protozoário/genética , Eimeria/classificação , Eimeria/crescimento & desenvolvimento , Complexo IV da Cadeia de Transporte de Elétrons/genética , Oocistos/citologia , Filogenia , Proteínas de Protozoários/genética , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Esporozoítos/citologia , Austrália Ocidental
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