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1.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(6): 631-634, 2020 Jul 31.
Artigo em Chinês | MEDLINE | ID: mdl-33325200

RESUMO

OBJECTIVE: To analyze the re-examination results of malaria cases captured from the National Notifiable Communicable Disease Reporting System in Hubei Provincial Malaria Diagnostic Reference Laboratory from 2017 to 2019, so as to pro- vide the scientific evidence for improving the malaria control capability in the province. METHODS: Microscopy and nested PCR assay were performed to re-examine the diagnosis of malaria cases registered in the National Notifiable Communicable Disease Reporting System in Hubei Provincial Malaria Diagnostic Reference Laboratory from 2017 to 2019, and the coincidences of ma- laria diagnosis and malaria parasite species were evaluated. RESULTS: A total of 410 malaria cases were reported in Hubei Province from 2017 to 2019 according to the data retrieved from the National Notifiable Communicable Disease Reporting System. Among the 407 samples re-examined by Hubei Provincial Malaria Diagnostic Reference Laboratory from 2017 to 2019, the diag- nosis 374 malaria cases were confirmed, with an overall coincidence of 91.89% (374/407) for malaria diagnosis and 89.04% (333/374) for parasite species identification. The coincidence rates of malaria diagnosis and parasite species identification were 50.00% to 100.00% and 66.67% to 100.00% in 16 cities (prefectures) of Hubei Province during the re-examinations, which both varied in regions (χ2 = 40.46 and 42.30, both P values < 0.01). The coincidence rates of Plasmodium falciparum, P. vivax, P. malariae and P. ovale identification were 95.80%, 100.00%, 58.33% and 51.92% during the re-examinations, respectively (χ2 = 76.66, P < 0.01). The consistency rate between microscopic and nested PCR results was 89.83% (362/403). CONCLUSIONS: The overall diagnostic quality of malaria is high in medical institutions at all levels in Hubei Province; however, the diagnostic capability of malaria remains to be improved in some regions.


Assuntos
Laboratórios/normas , Malária , China , Testes Diagnósticos de Rotina , Humanos , Malária/diagnóstico , Malária/epidemiologia , Plasmodium/classificação
2.
PLoS One ; 15(11): e0242713, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33227017

RESUMO

BACKGROUND: In efforts to control malaria infection, the Democratic Republic of Congo has implemented several strategies. Studies assessing their efficiency mainly involved at-risk groups, especially children under five years of age. This study aimed to determine the prevalence and identify the risk factors associated with Plasmodium spp. infection. METHODS: From October 2014 to March 2015, individuals aged at least 15 years were selected randomly and enrolled in a cross-sectional study conducted throughout the country. Microscopy and polymerase chain reaction (PCR) analysis were used for the detection of Plasmodium ssp. RESULTS: From 2286 individuals recruited, 1870 with valid laboratory results were included in the study for further analysis. The prevalence of Plasmodium spp. infection assessed by microscopy (355/ 1870 (19%) was lower than that estimated by PCR (580/1870 (31%). In addition, the difference between the two results was statistically significant (P < 0.0001). The most prevalent Plasmodium species was P. falciparum, either as mono-infection (96.3%; 95% C.I. 93.9-98.1) or combined with P. malariae (3.7%; 95% C.I. 2.8-5.9). The mean parasite density was 3272739 trophozoites/µL of blood. Women had higher risks of being infected than men (OR 2.03, 95% C.I.: 1.96. 2.62, P = 0.041)]. CONCLUSION: In this study, the molecular detection and species identification of Plasmodium spp. showed that, despite all efforts for malaria control, malaria remains a public health problem in the Democratic Republic of Congo. The high prevalence and parasite density of Plasmodium spp. in adults make this age group a potential parasitic infectious reservoir for the at-risk groups and supports the need to include this age group in further programs for malaria control.


Assuntos
Malária , Plasmodium , Reação em Cadeia da Polimerase , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , República Democrática do Congo/epidemiologia , Feminino , Humanos , Malária/sangue , Malária/epidemiologia , Malária/genética , Masculino , Pessoa de Meia-Idade , Plasmodium/classificação , Plasmodium/genética , Prevalência
3.
Proc Natl Acad Sci U S A ; 117(41): 25722-25731, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32958655

RESUMO

Asymptomatic carriers of Plasmodium parasites hamper malaria control and eradication. Achieving malaria eradication requires ultrasensitive diagnostics for low parasite density infections (<100 parasites per microliter blood) that work in resource-limited settings (RLS). Sensitive point-of-care diagnostics are also lacking for nonfalciparum malaria, which is characterized by lower density infections and may require additional therapy for radical cure. Molecular methods, such as PCR, have high sensitivity and specificity, but remain high-complexity technologies impractical for RLS. Here we describe a CRISPR-based diagnostic for ultrasensitive detection and differentiation of Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae, using the nucleic acid detection platform SHERLOCK (specific high-sensitivity enzymatic reporter unlocking). We present a streamlined, field-applicable, diagnostic comprised of a 10-min SHERLOCK parasite rapid extraction protocol, followed by SHERLOCK for 60 min for Plasmodium species-specific detection via fluorescent or lateral flow strip readout. We optimized one-pot, lyophilized, isothermal assays with a simplified sample preparation method independent of nucleic acid extraction, and showed that these assays are capable of detection below two parasites per microliter blood, a limit of detection suggested by the World Health Organization. Our P. falciparum and P. vivax assays exhibited 100% sensitivity and specificity on clinical samples (5 P. falciparum and 10 P. vivax samples). This work establishes a field-applicable diagnostic for ultrasensitive detection of asymptomatic carriers as well as a rapid point-of-care clinical diagnostic for nonfalciparum malaria species and low parasite density P. falciparum infections.


Assuntos
Portador Sadio/diagnóstico , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Técnicas e Procedimentos Diagnósticos , Técnicas Genéticas , Malária/diagnóstico , Plasmodium/genética , Plasmodium/isolamento & purificação , Portador Sadio/parasitologia , Humanos , Malária/parasitologia , Plasmodium/classificação , Plasmodium/fisiologia
4.
PLoS Pathog ; 16(8): e1008717, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745123

RESUMO

Hepatocystis is a genus of single-celled parasites infecting, amongst other hosts, monkeys, bats and squirrels. Although thought to have descended from malaria parasites (Plasmodium spp.), Hepatocystis spp. are thought not to undergo replication in the blood-the part of the Plasmodium life cycle which causes the symptoms of malaria. Furthermore, Hepatocystis is transmitted by biting midges, not mosquitoes. Comparative genomics of Hepatocystis and Plasmodium species therefore presents an opportunity to better understand some of the most important aspects of malaria parasite biology. We were able to generate a draft genome for Hepatocystis sp. using DNA sequencing reads from the blood of a naturally infected red colobus monkey. We provide robust phylogenetic support for Hepatocystis sp. as a sister group to Plasmodium parasites infecting rodents. We show transcriptomic support for a lack of replication in the blood and genomic support for a complete loss of a family of genes involved in red blood cell invasion. Our analyses highlight the rapid evolution of genes involved in parasite vector stages, revealing genes that may be critical for interactions between malaria parasites and mosquitoes.


Assuntos
Apicomplexa/genética , Sangue/parasitologia , Colobus/parasitologia , Malária/veterinária , Doenças dos Macacos/parasitologia , Plasmodium/genética , Infecções Protozoárias em Animais/parasitologia , Animais , Apicomplexa/classificação , Apicomplexa/fisiologia , Genoma de Protozoário , Malária/sangue , Malária/parasitologia , Doenças dos Macacos/sangue , Filogenia , Plasmodium/classificação , Plasmodium/fisiologia , Infecções Protozoárias em Animais/sangue , Transcriptoma
5.
Mem Inst Oswaldo Cruz ; 115: e200043, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32667459

RESUMO

BACKGROUND The number of malaria cases in Roraima nearly tripled from 2016 to 2018. The capital, Boa Vista, considered a low-risk area for malaria transmission, reported an increasing number of autochthonous and imported cases. OBJECTIVES This study describes a spatial analysis on malaria cases in an urban region of Boa Vista, which sought to identify the autochthonous and imported cases and associated them with Anopheles habitats and the potential risk of local transmission. METHODS In a cross-sectional study at the Polyclinic Cosme e Silva, 520 individuals were interviewed and diagnosed with malaria by microscopic examination. Using a global positional system, the locations of malaria cases by type and origin and the breeding sites of anopheline vectors were mapped and the risk of malaria transmission was evaluated by spatial point pattern analysis. FINDINGS Malaria was detected in 57.5% of the individuals and there was a disproportionate number of imported cases (90.6%) linked to Brazilian coming from gold mining sites in Venezuela and Guyana. MAIN CONCLUSIONS The increase in imported malaria cases circulating in the west region of Boa Vista, where there are positive breeding sites for the main vectors, may represent a potential condition for increased autochthonous malaria transmission in this space.


Assuntos
Anopheles/parasitologia , Malária/diagnóstico , Malária/transmissão , Mineradores/estatística & dados numéricos , Mosquitos Vetores/parasitologia , Plasmodium/isolamento & purificação , Viagem , Adulto , Animais , Anopheles/classificação , Brasil/epidemiologia , Estudos Transversais , Feminino , Sistemas de Informação Geográfica , Ouro , Guiana , Humanos , Malária/epidemiologia , Malária/parasitologia , Masculino , Pessoa de Meia-Idade , Plasmodium/classificação , Análise Espacial , População Urbana , Venezuela
6.
Mikrobiyol Bul ; 54(2): 306-317, 2020 Apr.
Artigo em Turco | MEDLINE | ID: mdl-32723285

RESUMO

Malaria is a life-threatening parasitic disease caused by the parasites belonging to Plasmodium genus. Microscopic examination of Giemsa stained blood smears is accepted as the gold standard diagnostic method. It is recommended to use more than one method in order to strengthen the laboratory diagnosis of malaria which is an important health problem in our country as in the whole world. In this study, it was aimed to compare the results of three different molecular methods and determine which molecular method could be used in the diagnostic algorithm to be applied. DNA was extracted from 280 whole blood sample stored in EDTA tubes using a commercial kit. Three different polymerase chain reaction (PCR) methods were used for the detection of Plasmodium spp. in DNA samples obtained and the results were compared. First, multiplex nested PCR was applied and then in-house real-time PCR (Rt-PCR) which was validated in our laboratory and a commercial Rt-PCR kit were applied. Multiplex nested PCR was accepted as the gold standard and 182 samples that were evaluated as Plasmodium spp. positive and 98 samples that were evaluated as negative were also studied by in-house and commercial Rt-PCR methods. In multiplex nested PCR's first step reaction 1670 base pairs (bp) band was observed in Plasmodium spp. positive samples and 117 bp band was observed in Plasmodium vivax positive samples in the second step reaction. Tm values of P.vivax positive samples were determined as 78-79 in the melting analysis of the in-house Rt-PCR. CT values of the positive samples in in-house Rt-PCR were between 20.03-31.71 and were between 17.26-34.94 in the commercial Rt-PCR. With the in-house Rt-PCR method 180 cases were determined as positive, while with the commercial Rt-PCR method 178 cases were determined as positive. Two samples with the in-house Rt-PCR and 4 samples with the commercial Rt-PCR were considered as false negative. When the sensitivity and specificity of the both methods were calculated, the sensitivity of the in-house Rt-PCR method was 0.98, the specificity was 0.97, the positive predictive value (PPV) was 98%, the negative predictive value (NPV) was 97%, the sensitivity of the commercial Rt-PCR was 0.97, the specificity was 0.95, the PPV was 97%, the NPV was 95%. A high level of agreement (κ: 0.953) was determined between the in-house and the commercial Rt-PCR methods. In order for a test to be accepted as a confirmatory test, its specificity must be high. It was decided that sensitivity and specificity of the in-house Rt-PCR were suitable for using this method in the laboratory diagnosis of Plasmodium species.


Assuntos
Malária , Reação em Cadeia da Polimerase Multiplex , Plasmodium , Reação em Cadeia da Polimerase em Tempo Real , DNA de Protozoário/genética , Humanos , Malária/sangue , Malária/diagnóstico , Malária/parasitologia , Reação em Cadeia da Polimerase Multiplex/normas , Plasmodium/classificação , Plasmodium/genética , Plasmodium falciparum/genética , Plasmodium vivax/genética , Reação em Cadeia da Polimerase em Tempo Real/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
7.
Rev Bras Parasitol Vet ; 29(3): e000920, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32667500

RESUMO

The aim of this study was to verify the presence and identify the species of haemosporidian parasites in eared doves (Zenaida auriculata) in Brazil. Two hundred and eleven male and female eared doves were trap-captured in four different regions of Londrina city, in southern Brazil. Whole blood was collected in EDTA tubes through heart puncture after euthanasia in a CO2 chamber. A nested PCR targeting the mitochondrial cytochrome b gene (cyt b) of Haemoproteus spp./Plasmodium spp. was performed, followed by an enzymatic digestion to identify the genus. Phylogenetic trees were constructed to determine the closely related species. Out of 211 eared doves, 209 (99.05%) were positive for Haemoproteus spp. and/or Plasmodium spp. RFLP analysis showed that 72.72% (152/209) of eared doves were positive only for Haemoproteus spp., 6.22% (13/209) were positive only for Plasmodium spp., and 21.05% (44/209) of eared doves had mixed infections. Genetic analysis found four samples that were homologous with Haemoproteus multipigmentatus and one that was homologous with Plasmodium sp. This is the first molecular study of hemoparasites from eared doves in Brazil, and it is also the first description of H. multipigmentatus and Plasmodium spp. infection in eared doves in Brazil.


Assuntos
Apicomplexa , Doenças das Aves , Columbidae , Plasmodium , Infecções Protozoárias em Animais , Animais , Apicomplexa/classificação , Apicomplexa/genética , Doenças das Aves/diagnóstico , Doenças das Aves/parasitologia , Brasil , Columbidae/parasitologia , Feminino , Masculino , Filogenia , Plasmodium/classificação , Plasmodium/genética , Reação em Cadeia da Polimerase/veterinária , Infecções Protozoárias em Animais/diagnóstico , Infecções Protozoárias em Animais/parasitologia
8.
Int J Infect Dis ; 98: 408-419, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32659450

RESUMO

BACKGROUND: Diagnosis is a challenging issue for eliminating malaria. Loop-mediated isothermal amplification (LAMP) could be an alternative to conventional methods. This study aimed to evaluate the diagnostic accuracy of LAMP for malaria compared with microscopy, polymerase chain reaction (PCR) and rapid diagnostic tests (RDTs). METHODS AND DESIGN: MEDLINE, Web of Science and Scopus were searched from inception to 1 July 2019. Prospective and retrospective, randomised and non-randomised, mono-center and multi-center studies, including symptomatic or asymptomatic patients, that reported one LAMP method and one comparator (microscopy, RDT or PCR) were included. PROSPERO registration number: CRD42017075186. RESULTS: Sixty-six studies published between 2006 and 2019 were included, leading to the analysis of 30,641 LAMP tests. The pooled sensitivity of LAMP remained between 96% and 98%, whichever the comparator. The pooled specificity of LAMP was around 95%, but was a little higher if the best PCR studies were considered. The AUC was found to be >0.98, whichever the subgroup of studies was considered. Diagnostic odds ratio (DOR) was found to be around 1000 for all subgroups, except for Plasmodium vivax. CONCLUSION: This meta-analysis confirmed that the LAMP method is robust for diagnosing malaria, both in symptomatic and asymptomatic people. Thus, the impact of LAMP for controlling malaria is expected to be important.


Assuntos
Testes Diagnósticos de Rotina/normas , Malária/diagnóstico , Microscopia/normas , Técnicas de Amplificação de Ácido Nucleico/normas , Plasmodium/isolamento & purificação , Reação em Cadeia da Polimerase/normas , Testes Diagnósticos de Rotina/métodos , Humanos , Malária/parasitologia , Microscopia/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Plasmodium/classificação , Plasmodium/genética , Plasmodium/fisiologia , Reação em Cadeia da Polimerase/métodos , Estudos Prospectivos , Estudos Retrospectivos , Sensibilidade e Especificidade
9.
Sci Rep ; 10(1): 11068, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32632180

RESUMO

Mixed Plasmodium malaria infections can lead to severe malaria. This systematic review and meta-analysis aimed to explore the prevalence of severe mixed Plasmodium malaria infection and to compare it with the prevalence of severe P. falciparum malaria mono-infection across the included studies. Original English-language research articles from PubMed, Scopus, and ISI Web of Science were identified and screened. Articles reporting the number of mixed infections and the number of severe mixed infections were used to determine the main outcome of this study, while the number of P. falciparum infections and the number of severe P. falciparum infections were used to determine the secondary outcome of this study. For the main outcome, the pooled prevalence and 95% confidence interval (CI) of severe mixed infections was analysed using STATA software version 15.0 (Stata Corp, College Station, TX, USA). For the secondary outcome, the rate of severe mixed infections compared to severe P. falciparum infections was analysed using the meta-analysis approach, and summary odds ratios (ORs) and 95% CIs were calculated. Random-effects models were used to produce the summary ORs. The Mantel-Haenszel method and calculated I2 were also reported to test whether there was heterogeneity among the included studies. Publication bias was also assessed using funnel plots. The meta-analysis of secondary outcomes was conducted using Review Manager 5.3 software (Cochrane Community). A total of 894,561 malaria patients were reported in all 16 included studies. Overall, a pooled analysis showed that 9% (2,006/35,768, 95% CI 7.0-12.0%) of patients with mixed Plasmodium infection had severe mixed infection. A meta-analysis of 14 studies demonstrated that patients with mixed Plasmodium infection (1,999/35,755) and patients with P. falciparum malaria (9,249/294,397) had an equal risk of developing severe malaria (OR 0.93, 95% CI 0.59-1.44). Both mixed infection and P. falciparum mono-infection showed a similar trend of complications in which severe anaemia, pulmonary failure, and renal impairment were the three most common complications found. However, patients with mixed infection had a higher proportion of severe anaemia and pulmonary complications than those with P. falciparum infection. Moreover, patients with mixed infection had a higher proportion of multiple organ failure than those with P. falciparum mono-infection. Mixed Plasmodium spp. infections were common but often unrecognized or underestimated, leading to severe complications among these malaria patients. Therefore, in routine clinical laboratories, using an accurate combination of diagnostic procedures to identify suspected patients with mixed infections is crucial for therapeutic decisions, prompt treatment, and effective patient management.


Assuntos
Coinfecção/epidemiologia , Malária/epidemiologia , Plasmodium/classificação , Plasmodium/patogenicidade , Índice de Gravidade de Doença , Coinfecção/parasitologia , Humanos , Malária/parasitologia , Plasmodium/isolamento & purificação , Prevalência
10.
Parasitol Res ; 119(8): 2631-2640, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32556500

RESUMO

The genus Plasmodium (Plasmodiidae) ranks among the most widespread intracellular protozoan parasites affecting a wide range of mammals, birds, and reptiles. Little information is available about lizard malaria parasites in South America, and the pathological features of the resulting parasitoses remain unknown or poorly understood. To partially fill in these gaps, we conducted blood smear analysis, molecular detection, and phylogenetic and pathological investigations in lizards inhabiting an Atlantic Forest fragment in Paraiba, Brazil. From 104 striped forest whiptails (Kentropyx calcarata) screened for the presence of haemosporidian parasites, 67 (64.4%) were positive. Four of five Amazon lava lizards (Strobilurus torquatus) we collected from this same area were also positive. A total of 27 forest whiptails were infected with a new genetic lineage of Plasmodium kentropyxi and other Plasmodium lineages were also detected. Histopathological analysis in infected forest whiptails revealed systemic intraerythrocytic Plasmodium stages, mainly gametocytes, in the liver, lung, and heart. Also, the liver of infected lizards had mild to moderate levels of Kupffer cell and melanomacrophage hypertrophy/hyperplasia with sinusoid leukocytosis. Overall, our findings suggest that an endemic Plasmodium species causes histological alterations that are not related to major pathological processes in striped forest whiptails.


Assuntos
Lagartos/parasitologia , Plasmodium/genética , Plasmodium/patogenicidade , Infecções Protozoárias em Animais/parasitologia , Animais , Brasil , Eritrócitos/parasitologia , Florestas , Fígado/parasitologia , Fígado/patologia , Filogenia , Plasmodium/classificação , Infecções Protozoárias em Animais/patologia
11.
Parasite ; 27: 34, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32410726

RESUMO

Microsatellites can be utilized to explore genotypes, population structure, and other genomic features of eukaryotes. Systematic characterization of microsatellites has not been a focus for several species of Plasmodium, including P. malariae and P. ovale, as the majority of malaria elimination programs are focused on P. falciparum and to a lesser extent P. vivax. Here, five human malaria species (P. falciparum, P. vivax, P. malariae, P. ovale curtisi, and P. knowlesi) were investigated with the aim of conducting in-depth categorization of microsatellites for P. malariae and P. ovale curtisi. Investigation of reference genomes for microsatellites with unit motifs of 1-10 base pairs indicates high diversity among the five Plasmodium species. Plasmodium malariae, with the largest genome size, displays the second highest microsatellite density (1421 No./Mbp; 5% coverage) next to P. falciparum (3634 No./Mbp; 12% coverage). The lowest microsatellite density was observed in P. vivax (773 No./Mbp; 2% coverage). A, AT, and AAT are the most commonly repeated motifs in the Plasmodium species. For P. malariae and P. ovale curtisi, microsatellite-related sequences are observed in approximately 18-29% of coding sequences (CDS). Lysine, asparagine, and glutamic acids are most frequently coded by microsatellite-related CDS. The majority of these CDS could be related to the gene ontology terms "cell parts," "binding," "developmental processes," and "metabolic processes." The present study provides a comprehensive overview of microsatellite distribution and can assist in the planning and development of potentially useful genetic tools for further investigation of P. malariae and P. ovale curtisi epidemiology.


Assuntos
Genoma de Protozoário , Repetições de Microssatélites , Plasmodium malariae/genética , Plasmodium ovale/genética , Plasmodium/genética , Ontologia Genética , Genótipo , Plasmodium/classificação , Sequências de Repetição em Tandem
12.
Acta Trop ; 209: 105542, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32470331

RESUMO

Transformation of natural environments for livestock, agriculture and human settlements modifies the diversity of organisms, usually decreasing in highly disturbed land uses. Like their hosts, parasites have to adapt to novel human impacted landscapes, in which the abiotic and biotic conditions are radically different from those of conserved natural environments. We evaluated the diversity (alpha and beta taxonomic and phylogenetic diversity) of haemosporidians (mtDNA cyt b lineages) in the common chlorospingus (Chlorospingus flavopectus) at five land use types. We further analyzed the response of prevalence, parasitaemia and parasite aggregation to land use types and seasonality. Parasite lineage richness (i.e., haplotypes) and abundance (no. infected hosts) decreased with disturbance. Parasite assemblages were commonly dominated by either one of two lineages, one dominant in the urban greenspace (pBAEBIC02) and the other dominant in well-preserved mountain cloud forest (hCHLFLA01). Beta diversity was mainly explained by lineage turnover. Phylo beta diversity was low (i.e., lineages are closely related). Overall prevalence increased in wet season that coincides with host's breeding season. Haemoproteus and Plasmodium prevalence presented the opposite response to urbanization (negative and positive, respectively). Parasitaemia presented similar values across land uses for both genera and seasons, while Plasmodium aggregation decreased with urbanization. Thus, some parasite lineages (pBAEBIC02) will benefit from the urbanization process, while others will entirely disappear from cities (hCHLFLA01).


Assuntos
Haemosporida/isolamento & purificação , Passeriformes/parasitologia , Urbanização , Animais , Haemosporida/classificação , Haemosporida/genética , Parasitemia/veterinária , Filogenia , Plasmodium/classificação , Plasmodium/genética , Plasmodium/isolamento & purificação , Estações do Ano
13.
Parasit Vectors ; 13(1): 170, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32252804

RESUMO

Serine repeat antigen (SERA) is conserved among species of the genus Plasmodium. Sera genes form a multigene family and are generally tandemly clustered on a single chromosome. Although all Plasmodium species encode multiple sera genes, the number varies between species. Among species, the members share similar sequences and gene organization. SERA possess a central papain-like cysteine protease domain, however, in some members, the active site cysteine residue is substituted with a serine. Recent studies implicate this gene family in a number of aspects in parasite biology and induction of protective immune response. This review summarizes the current understanding on this important gene family in several Plasmodium species. The Plasmodium falciparum (Pf)-sera family, for example, consists of nine gene members. Unlike other multigene families in Plasmodium species, Pf-sera genes do not exhibit antigenic variation. Pf-sera5 nucleotide diversity is also low. Moreover, although Pf-sera5 is highly transcribed during the blood stage of malaria infection, and a large amount is released into the host blood following schizont rupture, in malaria endemic countries the sero-positive rates for Pf-SERA5 are low, likely due to Pf-SERA5 binding of host proteins to avoid immune recognition. As an antigen, the N-terminal 47 kDa domain of Pf-SERA5 is a promising vaccine candidate currently undergoing clinical trials. Pf-SERA5 and Pf-SERA6, as well as P. berghei (Pb)-SERA3, and Pb-SERA5, have been investigated for their roles in parasite egress. Two P. yoelii SERA, which have a serine residue at the protease active center, are implicated in parasite virulence. Overall, these studies provide insight that during the evolution of the Plasmodium parasite, the sera gene family members have increased by gene duplication, and acquired various functions that enable the parasite to survive and successfully maintain infection in the host.


Assuntos
Antígenos de Protozoários/genética , Família Multigênica , Plasmodium/genética , Proteínas de Protozoários/genética , Sequência de Aminoácidos , Animais , Interações Hospedeiro-Parasita/genética , Humanos , Filogenia , Plasmodium/classificação
14.
J Zoo Wildl Med ; 51(1): 140-149, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32212557

RESUMO

Vector-borne Plasmodium spp. infect a wide range of bird species. Although infections may be asymptomatic, certain genera, especially those that evolved in regions without endemic malaria, appear particularly susceptible to symptomatic disease, leading to morbidity and mortality. High mortalities associated with malaria infections have been documented in captive species of Sphenisciformes, Somateria, and Larosterna, all genera that evolved in climates with low mosquito exposure. To better characterize trends in Plasmodium-related mortality in a zoological collection in New York, necropsy reports for birds of all three genera that died between 1998 and February 2018 were analyzed; comparisons were made between birds that died with or without evidence of malaria infection. A seasonal peak in deaths was observed in birds regardless of their malaria status. There was no significant difference in the age of birds at death between malaria-positive and malaria-negative animals. These results suggest that age and season of death were not associated with malaria status. To investigate an association between parasite lineage and clinical outcome, polymerase chain reaction was used to identify parasite lineage in necropsied birds as well as healthy birds sampled as part of surveillance studies. Twelve different Plasmodium lineages were identified. The relative prevalence of parasite lineages was compared between necropsy and surveillance samples. A single parasite lineage, SGS1 (species: Plasmodium relictum), was significantly more likely to be found in surveillance samples; it was detected in a plurality of surveillance data but found in only one necropsy case. Other parasite lineages were more likely to be found in necropsies than in surveillance samples, most notably SEIAUR01 (species: Plasmodium cathemerium). These data may be consistent with a difference in virulence between parasite lineages. This investigation has implications for the monitoring and care of vulnerable avian species.


Assuntos
Animais de Zoológico , Charadriiformes , Patos , Malária Aviária/parasitologia , Spheniscidae , Animais , New York , Filogenia , Plasmodium/classificação , Plasmodium/isolamento & purificação
15.
BMC Genomics ; 21(1): 236, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32183702

RESUMO

BACKGROUND: The Plasmodium genus of malaria parasites encodes several families of antigen-encoding genes. These genes tend to be hyper-variable, highly recombinogenic and variantly expressed. The best-characterized family is the var genes, exclusively found in the Laveranian subgenus of malaria parasites infecting humans and great apes. Var genes encode major virulence factors involved in immune evasion and the maintenance of chronic infections. In the human parasite P. falciparum, var gene recombination and diversification appear to be promoted by G-quadruplex (G4) DNA motifs, which are strongly associated with var genes in P. falciparum. Here, we investigated how this association might have evolved across Plasmodium species - both Laverania and also more distantly related species which lack vars but encode other, more ancient variant gene families. RESULTS: The association between var genes and G4-forming motifs was conserved across Laverania, spanning ~ 1 million years of evolutionary time, with suggestive evidence for evolution of the association occurring within this subgenus. In rodent malaria species, G4-forming motifs were somewhat associated with pir genes, but this was not conserved in the Laverania, nor did we find a strong association of these motifs with any gene family in a second outgroup of avian malaria parasites. Secondly, we compared two different G4 prediction algorithms in their performance on extremely A/T-rich Plasmodium genomes, and also compared these predictions with experimental data from G4-seq, a DNA sequencing method for identifying G4-forming motifs. We found a surprising lack of concordance between the two algorithms and also between the algorithms and G4-seq data. CONCLUSIONS: G4-forming motifs are uniquely strongly associated with Plasmodium var genes, suggesting a particular role for G4s in recombination and diversification of these genes. Secondly, in the A/T-rich genomes of Plasmodium species, the choice of prediction algorithm may be particularly influential when studying G4s in these important protozoan pathogens.


Assuntos
Quadruplex G , Malária/parasitologia , Motivos de Nucleotídeos , Plasmodium/genética , Plasmodium/patogenicidade , Proteínas de Protozoários/genética , Animais , Filogenia , Plasmodium/classificação , Virulência/genética
16.
Turkiye Parazitol Derg ; 44(1): 1-6, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32212581

RESUMO

Objective: Malaria is an important infectious disease that is transmitted by female mosquitoes of the genus Anopheles infected with parasites of the genus Plasmodium. In this research, it was aimed to contribute to the ongoing studies on malaria control in Antalya. Methods: In this study, malaria data between 2012-2017 obtained from Antalya Provincial Directorate of Health were used. The patients with malaria were evaluated in terms of the years and months they were detected in, age group, gender, parasite species which were detected and their sources. Results: During the 6-year period, a total of 1905 blood samples were surveyed and 36 (1.89%) patients were reported. The most patients occurred in June and August (5 patients in each month, 13.89%). Of the patients, 94.44% (34 patients) were 15 years old and over. By gender, 83.33% (n=30) of patients were male, 16.67% (n=6) were female. The disease agent responsible for most of the patients with malaria was P. falciparum (80.55%, 29 patients), followed by P. vivax (11.11%, 4 patients), P. ovale (5.56%, 2 patients) and P. malariae (2.78%, 1 patient). All patients with malaria were from abroad. Conclusion: For malaria control, studies on the early diagnosis and treatment of the disease and the integrated mosquito control programs should be uninterruptedly maintained.


Assuntos
Malária/epidemiologia , Plasmodium/classificação , Adolescente , Adulto , Idoso , Animais , Anopheles/parasitologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Malária/diagnóstico , Malária/parasitologia , Malária/prevenção & controle , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores/parasitologia , Estações do Ano , Inquéritos e Questionários , Viagem , Turquia/epidemiologia , Adulto Jovem
17.
Acta Trop ; 204: 105364, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32007445

RESUMO

Haemosporidian parasites of the genera Plasmodium, Leucocytozoon, and Haemoproteus are one of the most prevalent and widely studied groups of parasites infecting birds. Plasmodium is the most well-known haemosporidian as the avian parasite Plasmodium relictum was the original transmission model for human malaria and was also responsible for catastrophic effects on native avifauna when introduced to Hawaii. The past two decades have seen a dramatic increase in research on avian haemosporidian parasites as a model system to understand evolutionary and ecological parasite-host relationships. Despite haemosporidians being one the best studied groups of avian parasites their specialization among avian hosts and variation in prevalence amongst regions and host taxa are not fully understood. In this review we focus on describing the current phylogenetic and morphological diversity of haemosporidian parasites, their specificity among avian and vector hosts, and identifying the determinants of haemosporidian prevalence among avian species. We also discuss how these parasites might spread across regions due to global climate change and the importance of avian migratory behavior in parasite dispersion and subsequent diversification.


Assuntos
Malária Aviária/epidemiologia , Plasmodium/classificação , Animais , Aves/parasitologia , Mudança Climática , Ecologia , Haemosporida/classificação , Hawaii/epidemiologia , Interações Hospedeiro-Parasita , Malária Aviária/parasitologia , Filogenia , Plasmodium/fisiologia , Prevalência
18.
Parasitol Int ; 76: 102069, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32032726

RESUMO

Plasmodium malariae mainly causes asymptomatic submicroscopic parasitemia in the endemic Amazon and non-endemic Atlantic Forest, where the number of cases and transmission of malaria through blood transfusion has increased. This study developed a P. malariae/P. brasilianum Real Time PCR (rtPCR) targeting the cytochrome b oxidase (cytb), a highly repetitive gene (20-150 copies/parasite) that should detect more cases than the 18S rRNA (4-8 copies/parasite) gene-based amplification systems. Cytb from human and non-human Plasmodium species (including P. brasilianum) aligned to the only 20 African P. malariae cytb sequences identified polymorphic regions within which we designed P. malariae species-specific primers. Non-human Plasmodium species, related parasites, anemia-causing microorganisms, normal human DNA and 47 blood bank donors samples that were truly negative to malaria accessed rtPCR specificity. Truly positive samples (n = 101) with species identification by semi-nested, nested or TaqMan PCR, and four samples from the Atlantic Forest that were suspected of malaria but three of them had negative genus TaqMan and 18S rRNA nested PCR. The cloned amplification product used in standard curves determined qPCR detection limit (0.5-1 parasite equivalent/µL). The 10 positive P. malariae samples among truly positives yielded positive rtPCR results and more importantly, rtPCR detected the four samples suspected of malaria from the Atlantic Forest. The rtPCR specificity was 100%, reproducibility 11.1% and repeatability 6.7%. In conclusion, the proposed rtPCR is fast, apparently more sensitive than all 18S rRNA amplification systems for detecting extremely low parasitemia. The rtPCR is also specific to P. malariae/P. brasilianum species. This new molecular tool could be applied to the detection of P. malariae/brasilianum infections with submicroscopic parasitemias in the context of epidemiological studies and blood bank safety programs.


Assuntos
Citocromos b/análise , Plasmodium/genética , Proteínas de Protozoários/análise , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Proteínas Mitocondriais/análise , Compostos Orgânicos/química , Plasmodium/classificação , Plasmodium malariae/classificação , Plasmodium malariae/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reprodutibilidade dos Testes , Especificidade da Espécie
19.
Malar J ; 19(1): 69, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050970

RESUMO

BACKGROUND: Passerine birds are frequently infected with diverse haemosporidian parasites. While infections are traditionally considered benign in wild birds, recent studies demonstrated mortalities of passerine species due to exo-erythrocytic development of the parasites, which can damage organs in affected hosts. However, exo-erythrocytic development remains insufficiently investigated for most haemosporidian species and thus little is known about the virulence of tissue stages in wild passerine birds. The aim of the present study was to investigate natural haemosporidian infections in deceased Eurasian blackbirds (Turdus merula) and song thrushes (Turdus philomelos) and to determine parasite burden and associated histological effects. METHODS: For molecular analysis, blood and tissue samples from 306 thrushes were screened for Plasmodium, Haemoproteus and Leucocytozoon parasites by nested PCR. For the detection of parasite stages in organ samples, tissue sections were subjected to chromogenic in situ hybridization (CISH) using genus- and species-specific probes targeting the rRNAs of parasites. Exo-erythrocytic parasite burden was semi-quantitatively assessed and histological lesions were evaluated in haematoxylin-eosin-stained sections. RESULTS: By PCR, 179 of 277 Eurasian blackbirds and 15 of 29 song thrushes were positive for haemosporidians. Parasites of all three genera were detected, with Plasmodium matutinum LINN1 and Plasmodium vaughani SYAT05 showing the highest prevalence. CISH revealed significant differences in exo-erythrocytic parasite burden between lineages in Eurasian blackbirds, with P. matutinum LINN1 frequently causing high exo-erythrocytic parasite burdens in various organs that were associated with histological alterations. Song thrushes infected with P. matutinum LINN1 and birds infected with other haemosporidian lineages showed mostly low exo-erythrocytic parasite burdens. Two Eurasian blackbirds infected with Leucocytozoon sp. TUMER01 showed megalomeronts in various organs that were associated with inflammatory reactions and necroses. CONCLUSION: This study suggests that P. matutinum LINN1, a common lineage among native thrushes, regularly causes high exo-erythrocytic parasite burdens in Eurasian blackbirds, which may result in disease and mortalities, indicating its high pathogenic potential. The findings further illustrate that the same parasite lineage may show different levels of virulence in related bird species which should be considered when assessing the pathogenicity of haemosporidian parasite species. Finally, the study provides evidence of virulent Leucocytozoon sp. TUMER01 infections in two Eurasian blackbirds caused by megalomeront formation.


Assuntos
Doenças das Aves/parasitologia , Haemosporida/fisiologia , Infecções Protozoárias em Animais/parasitologia , Aves Canoras/parasitologia , Animais , Animais Selvagens , Áustria , Bolsa de Fabricius/parasitologia , DNA de Protozoário/genética , DNA de Protozoário/isolamento & purificação , Haemosporida/genética , Haemosporida/isolamento & purificação , Haemosporida/patogenicidade , Coração/parasitologia , Hibridização In Situ/métodos , Hibridização In Situ/veterinária , Rim/parasitologia , Plasmodium/classificação , Plasmodium/genética , Plasmodium/isolamento & purificação , Reação em Cadeia da Polimerase/veterinária , Especificidade da Espécie , Virulência
20.
Malar J ; 19(1): 68, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32046739

RESUMO

Malaria is major public health concerns which continues to claim the lives of more than 435,000 people each year. The challenges with anti-malarial drug resistance and detection of low parasitaemia forms an immediate barrier to achieve the fast-approaching United Nations Sustainable Development Goals of ending malaria epidemics by 2030. In this Opinion article, focusing on the recent published technologies, in particularly the nuclear magnetic resonance (NMR)-based diagnostic technologies, the authors offer their perspectives and highlight ways to bring these point-of-care technologies towards personalized medicine. To this end, they advocate an open sourcing initiative to rapidly close the gap between technological innovations and field implementation.


Assuntos
Hemeproteínas/análise , Espectroscopia de Ressonância Magnética/métodos , Malária/diagnóstico , Testes Imediatos , Medicina de Precisão/métodos , Animais , Resistência a Medicamentos , Hemeproteínas/química , Hemeproteínas/metabolismo , Humanos , Malária/epidemiologia , Malária/parasitologia , Fenótipo , Plasmodium/classificação , Plasmodium/efeitos dos fármacos , Plasmodium/genética , Sensibilidade e Especificidade
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