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PLoS Pathogens Jun 2024
Review
Topics: Malaria Vaccines; Humans; Vaccine Development; Malaria; Animals; Plasmodium falciparum; Malaria, Falciparum
PubMed: 38935630
DOI: 10.1371/journal.ppat.1012309 -
ELife Jun 2024The Zanzibar archipelago of Tanzania has become a low-transmission area for . Despite being considered an area of pre-elimination for years, achieving elimination has...
BACKGROUND
The Zanzibar archipelago of Tanzania has become a low-transmission area for . Despite being considered an area of pre-elimination for years, achieving elimination has been difficult, likely due to a combination of imported infections from mainland Tanzania and continued local transmission.
METHODS
To shed light on these sources of transmission, we applied highly multiplexed genotyping utilizing molecular inversion probes to characterize the genetic relatedness of 282 isolates collected across Zanzibar and in Bagamoyo district on the coastal mainland from 2016 to 2018.
RESULTS
Overall, parasite populations on the coastal mainland and Zanzibar archipelago remain highly related. However, parasite isolates from Zanzibar exhibit population microstructure due to the rapid decay of parasite relatedness over very short distances. This, along with highly related pairs within , suggests ongoing low-level local transmission. We also identified highly related parasites across that reflect human mobility on the main island of Unguja and identified a cluster of highly related parasites, suggestive of an outbreak, in the Micheweni district on Pemba island. Parasites in asymptomatic infections demonstrated higher complexity of infection than those in symptomatic infections, but have similar core genomes.
CONCLUSIONS
Our data support importation as a main source of genetic diversity and contribution to the parasite population in Zanzibar, but they also show local outbreak clusters where targeted interventions are essential to block local transmission. These results highlight the need for preventive measures against imported malaria and enhanced control measures in areas that remain receptive to malaria reemergence due to susceptible hosts and competent vectors.
FUNDING
This research was funded by the National Institutes of Health, grants R01AI121558, R01AI137395, R01AI155730, F30AI143172, and K24AI134990. Funding was also contributed from the Swedish Research Council, Erling-Persson Family Foundation, and the Yang Fund. RV acknowledges funding from the MRC Centre for Global Infectious Disease Analysis (reference MR/R015600/1), jointly funded by the UK Medical Research Council (MRC) and the UK Foreign, Commonwealth & Development Office (FCDO), under the MRC/FCDO Concordat agreement and is also part of the EDCTP2 program supported by the European Union. RV also acknowledges funding by Community Jameel.
Topics: Tanzania; Plasmodium falciparum; Malaria, Falciparum; Humans; Genotype
PubMed: 38935423
DOI: 10.7554/eLife.90173 -
Microorganisms May 2024Bacteria, fungi, and protists occupy a pivotal position in maintaining soil ecology. Despite limited knowledge on their responses to managed vegetation restoration...
Bacteria, fungi, and protists occupy a pivotal position in maintaining soil ecology. Despite limited knowledge on their responses to managed vegetation restoration strategies in karst regions, we aimed to study the essential microbial communities involved in the process of vegetation restoration. We compared microbial characteristics in four land use types: planted forests (PF), forage grass (FG), a mixture of plantation forest and forage grass (FF), and cropland (CR) as a reference. Our findings revealed that the richness of bacteria and protists was higher in FF compared to PF, while fungal richness was lower in both PF and FF than in CR. Additionally, the bacterial Shannon index in FF was higher than that in CR and PF, while the fungal and protist Shannon indices were similar across all four land use types. Significant differences were observed in the compositions of bacterial, fungal, and protist communities between FF and the other three land use types, whereas bacterial, fungal, and protist communities were relatively similar in PF and FG. In FF, the relative abundance of bacterial taxa Acidobacteria, Firmicutes, and Gemmatimonadetes was significantly higher than in PF and CR. Fungal communities were dominated by Ascomycota and Basidiomycota, with the relative abundance of Ascomycota significantly higher in FF compared to other land use types. Regarding protistan taxa, the relative abundance of Chlorophyta was higher in FF compared to CR, PF, and FG, while the relative abundance of Apicomplexa was higher in CR compared to FF. Importantly, ammonium nitrogen, total phosphorus, and microbial biomass nitrogen were identified as key soil properties predicting changes in the diversity of bacteria, fungi, and protists. Our results suggest that the microbial community under FF exhibits greater sensitivity to vegetation restoration compared to PF and FG. This sensitivity may stem from differences in soil properties, the formation of biological crusts and root systems, and management activities, resulting in variations in bacterial, fungal, and protist diversity and taxa in PF. As a result, employing a combination restoration strategy involving plantation forest and forage grass proves to be an effective approach to enhance the microbial community and thereby improve ecosystem functionality in ecologically fragile areas.
PubMed: 38930456
DOI: 10.3390/microorganisms12061074 -
Life (Basel, Switzerland) May 2024Rabbit coccidiosis is caused by infection with one or, more commonly, several species that parasitize the hepatobiliary ducts or intestinal epithelium of rabbits....
Rabbit coccidiosis is caused by infection with one or, more commonly, several species that parasitize the hepatobiliary ducts or intestinal epithelium of rabbits. Currently, there are eleven internationally recognized species of rabbit coccidia, with the complete mitochondrial (mt) genomes of six species commonly infecting rabbits having been sequenced and annotated. was initially discovered in 2011 and prompted a preliminary study on this species. Through traditional morphological analysis, was identified as a novel species of rabbit coccidia. To further validate this classification, we sequenced and annotated its mitochondrial genome. The complete mt genome of spans 6258 bp and comprises three cytochrome genes (), fourteen gene fragments for the large subunit (LSU) rRNA, and nine gene fragments for the small subunit (SSU) rRNA, lacking transfer RNA (tRNA) genes. Moreover, phylogenetic analysis of the mitochondrial genome sequence of revealed its clustering with six other species of rabbit coccidia into a monophyletic group. Additionally, and were grouped within the lineage lacking oocyst residuum, consistent with their morphological characteristics. Consistent with multiple molecular phylogenies, in this investigation, was further confirmed as a new species of rabbit coccidia. Our research findings are of great significance for the classification of coccidia and for coccidiosis prevention and control in rabbits.
PubMed: 38929682
DOI: 10.3390/life14060699 -
Medicina (Kaunas, Lithuania) Jun 2024: Malaria continues to be a significant global health challenge. The efficacy of artemisinin-based combination therapies (ACTs) has declined in many parts of the Greater...
: Malaria continues to be a significant global health challenge. The efficacy of artemisinin-based combination therapies (ACTs) has declined in many parts of the Greater Mekong Subregion, including Vietnam, due to the spread of resistant malaria strains. This study was conducted to assess the efficacy of the Dihydroartemisinin (DHA)-Piperaquine (PPQ) regimen in treating uncomplicated malaria and to conduct molecular surveillance of antimalarial drug resistance in Binh Phuoc and Dak Nong provinces. : The study included 63 uncomplicated malaria falciparum patients from therapeutic efficacy studies (TES) treated following the WHO treatment guidelines (2009). Molecular marker analysis was performed on all 63 patients. Methods encompassed Sanger sequencing for mutations and quantitative real-time PCR for the gene. : This study found a marked decrease in the efficacy of the DHA-PPQ regimen, with an increased rate of treatment failures at two study sites. Genetic analysis revealed a significant presence of mutations and amplifications, indicating emerging resistance to artemisinin and its partner drug. : The effectiveness of the standard DHA-PPQ regimen has sharply declined, with rising treatment failure rates. This decline necessitates a review and possible revision of national malaria treatment guidelines. Importantly, molecular monitoring and clinical efficacy assessments together provide a robust framework for understanding and addressing detection drug resistance in malaria.
Topics: Humans; Artemisinins; Quinolines; Vietnam; Antimalarials; Malaria, Falciparum; Male; Female; Adult; Plasmodium falciparum; Drug Resistance; Adolescent; Middle Aged; Drug Therapy, Combination; Young Adult; Protozoan Proteins; Real-Time Polymerase Chain Reaction; Mutation; Piperazines
PubMed: 38929629
DOI: 10.3390/medicina60061013 -
International Journal of Environmental... May 2024Multidrug- and artemisinin-resistant (ART-R) parasites represent a challenge for malaria elimination worldwide. Molecular monitoring in the Kelch domain region gene...
Multidrug- and artemisinin-resistant (ART-R) parasites represent a challenge for malaria elimination worldwide. Molecular monitoring in the Kelch domain region gene allows tracking mutations in parasite resistance to artemisinin. The increase in illegal miners in the Roraima Yanomami indigenous land (YIL) could favor ART-R parasites. Thus, this study aimed to investigate ART-R in patients from illegal gold mining areas in the YIL of Roraima, Brazil. A questionnaire was conducted, and blood was collected from 48 patients diagnosed with or mixed malaria (). The DNA was extracted and the gene was amplified by PCR. The amplicons were subjected to DNA-Sanger-sequencing and the entire amplified fragment was analyzed. Among the patients, 96% (46) were from illegal mining areas of the YIL. All parasite samples carried the wild-type genotypes/ART-sensitive phenotypes. These data reinforce the continued use of artemisinin-based combination therapies (ACTs) in Roraima, as well as the maintenance of systematic monitoring for early detection of parasite populations resistant to ART, mainly in regions with an intense flow of individuals from mining areas, such as the YIL. This is especially true when the achievement of falciparum malaria elimination in Brazil is planned and expected by 2030.
Topics: Artemisinins; Brazil; Plasmodium falciparum; Humans; Antimalarials; Drug Resistance; Malaria, Falciparum; Male; Mining; Adult; Female; Middle Aged; Young Adult; Adolescent; Genotype
PubMed: 38928926
DOI: 10.3390/ijerph21060679 -
Genes May 2024Malaria results in more than 550,000 deaths each year due to drug resistance in the most lethal () species . A full genome was published in 2002, yet 44.6% of its...
BACKGROUND
Malaria results in more than 550,000 deaths each year due to drug resistance in the most lethal () species . A full genome was published in 2002, yet 44.6% of its genes have unknown functions. Improving the functional annotation of genes is important for identifying drug targets and understanding the evolution of drug resistance.
RESULTS
Genes function by interacting with one another. So, analyzing gene co-expression networks can enhance functional annotations and prioritize genes for wet lab validation. Earlier efforts to build gene co-expression networks in have been limited to a single network inference method or gaining biological understanding for only a single gene and its interacting partners. Here, we explore multiple inference methods and aim to systematically predict functional annotations for all genes. We evaluate each inferred network based on how well it predicts existing gene-Gene Ontology (GO) term annotations using network clustering and leave-one-out crossvalidation. We assess overlaps of the different networks' edges (gene co-expression relationships), as well as predicted functional knowledge. The networks' edges are overall complementary: 47-85% of all edges are unique to each network. In terms of the accuracy of predicting gene functional annotations, all networks yielded relatively high precision (as high as 87% for the network inferred using mutual information), but the highest recall reached was below 15%. All networks having low recall means that none of them capture a large amount of all existing gene-GO term annotations. In fact, their annotation predictions are highly complementary, with the largest pairwise overlap of only 27%. We provide ranked lists of inferred gene-gene interactions and predicted gene-GO term annotations for future use and wet lab validation by the malaria community.
CONCLUSIONS
The different networks seem to capture different aspects of the biology in terms of both inferred interactions and predicted gene functional annotations. Thus, relying on a single network inference method should be avoided when possible.
SUPPLEMENTARY DATA
Attached.
Topics: Plasmodium falciparum; Gene Regulatory Networks; Malaria, Falciparum; Humans; Gene Ontology; Molecular Sequence Annotation; Protozoan Proteins
PubMed: 38927622
DOI: 10.3390/genes15060685 -
Malaria Journal Jun 2024Although Tanzania adopted and has been implementing effective interventions to control and eventually eliminate malaria, the disease is still a leading public health...
High prevalence and risk of malaria among asymptomatic individuals from villages with high prevalence of artemisinin partial resistance in Kyerwa district of Kagera region, north-western Tanzania.
BACKGROUND
Although Tanzania adopted and has been implementing effective interventions to control and eventually eliminate malaria, the disease is still a leading public health problem, and the country experiences heterogeneous transmission. Recent studies reported the emergence of parasites with artemisinin partial resistance (ART-R) in Kagera region with high prevalence (> 10.0%) in two districts of Karagwe and Kyerwa. This study assessed the prevalence and predictors/risk of malaria infections among asymptomatic individuals living in a hyperendemic area where ART-R has emerged in Kyerwa District of Kagera region, north-western Tanzania.
METHODS
This was a community-based cross-sectional survey which was conducted in July and August 2023 and involved individuals aged ≥ 6 months from five villages in Kyerwa district. Demographic, anthropometric, clinical, parasitological, type of house inhabited and socio-economic status (SES) data were collected using electronic capture tools run on Open Data Kit (ODK) software. Predictors/risks of malaria infections were determined by univariate and multivariate logistic regression, and the results were presented as crude (cORs) and adjusted odds ratios (aORs), with 95% confidence intervals (CIs).
RESULTS
Overall, 4454 individuals were tested using rapid diagnostic tests (RDTs), and 1979 (44.4%) had positive results. The prevalence of malaria infections ranged from 14.4% to 68.5% and varied significantly among the villages (p < 0.001). The prevalence and odds of infections were significantly higher in males (aOR = 1.28, 95% CI 1.08 -1.51, p = 0.003), school children (aged 5-≤10 years (aOR = 3.88, 95% CI 3.07-4.91, p < 0.001) and 10-≤15 years (aOR = 4.06, 95% CI 3.22-5.13, p < 0.001)) and among individuals who were not using bed nets (aOR = 1.22, 95% CI 1.03-1.46, p = 0.024). The odds of malaria infections were also higher in individuals with lower SES (aOR = 1.42, 95% CI 1.17-1.72, p < 0.001), and living in houses without windows (aOR = 2.08, 95% CI 1.46-2.96, p < 0.001), partially open (aOR = 1.33, 95% CI 1.11-1.58, p = 0.002) or fully open windows (aOR = 1.30, 95%CI 1.05-1.61, p = 0.015).
CONCLUSION
The five villages had a high prevalence of malaria infections and heterogeneity at micro-geographic levels. Groups with higher odds of malaria infections included school children, males, and individuals with low SES, living in poorly constructed houses or non-bed net users. These are important baseline data from an area with high prevalence of parasites with ART-R and will be useful in planning interventions for these groups, and in future studies to monitor the trends and potential spread of such parasites, and in designing a response to ART-R.
Topics: Tanzania; Male; Prevalence; Female; Humans; Artemisinins; Cross-Sectional Studies; Child; Child, Preschool; Adolescent; Adult; Young Adult; Antimalarials; Middle Aged; Infant; Drug Resistance; Malaria; Aged; Malaria, Falciparum; Risk Factors; Plasmodium falciparum
PubMed: 38926854
DOI: 10.1186/s12936-024-05019-5 -
Journal of Vector Borne Diseases Apr 2024Vector-borne haemoprotozoan diseases comprise diverse group of single celled organism transmitted by haematophagus invertebrates. The current study was aimed at the...
BACKGROUND OBJECTIVES
Vector-borne haemoprotozoan diseases comprise diverse group of single celled organism transmitted by haematophagus invertebrates. The current study was aimed at the identification of major haemoprotozoan (Babesia, Theileria and Trypanosoma) in dromedary camel of North Gujarat region in India using microscopy and Polymerase Chain Reaction (PCR).
METHODS
A total of 234 blood samples were screened by the microscopic and molecular detection assays. Molecular prevalence studies of Theileria, Trypanosoma spp and Babesia was undertaken using 18s ribosomal DNA, RoTat 1.2 and SS rRNA gene respectively. The data relating to microscopic and molecular prevalence along with associated risk factors were analysed by statistical methods.
RESULTS
The overall prevalence of hamoprotozoan disease based on microscopic and molecular investigation was 23.50%. The sensitivity and specificity (95% Confidence Interval) of PCR assay was 100% in comparison to microscopy (45.45 % sensitive and 100 % specific). The kappa coefficient between PCR and microscopy indicated good level of agreement with a value of 0.704 and SE of 0.159.
INTERPRETATION CONCLUSION
Despite holding much significance to the animal sector, little work has been undertaken in regional parts of India regarding camel parasites. The present study offers first preliminary research data investigating haemoprotozoan disease using parasitological and molecular methods in camels in the region.
Topics: Animals; Camelus; India; Polymerase Chain Reaction; Microscopy; Trypanosoma; Theileria; Babesia; Theileriasis; RNA, Ribosomal, 18S; DNA, Protozoan; Babesiosis; Prevalence; Male; Sensitivity and Specificity; Trypanosomiasis; Female; Vector Borne Diseases; DNA, Ribosomal
PubMed: 38922661
DOI: 10.4103/jvbd.jvbd_105_23 -
Journal of Vector Borne Diseases Apr 2024Plasmodium knowlesi, a simian malaria species, is now known to infect humans. Due to disadvantages in the current diagnosis methods, many efforts have been placed into...
Detection of Plasmodium knowlesi in whole blood samples with sandwich enzyme-linked immunosorbent assay (ELISA) using rhoptry-associated protein 1 specific polyclonal antibodies.
BACKGROUND OBJECTIVES
Plasmodium knowlesi, a simian malaria species, is now known to infect humans. Due to disadvantages in the current diagnosis methods, many efforts have been placed into developing new methods to diagnose the disease. This study assessed the ability of the PkRAP-1 sandwich enzyme-linked immunosorbent (ELISA) to detect P knowlesi antigens in whole blood specimens.
METHODS
Western blot assay was conducted to evaluate the ability of raised mouse and rabbit anti-PkRAP-1 polyclonal antibodies to bind to the native proteins in P. knowlesi lysate. The polyclonal antibodies were then used in sandwich ELISA to detect P. knowlesi. In the sandwich ELISA, mouse and rabbit polyclonal antibodies were used as the capture and detection antibodies, respectively. The limit of detection (LOD) of the assay was determined using P. knowlesi A1H1 culture and purified recombinant PkRAP-1.
RESULTS
Western blot results showed positive reactions towards the proteins in P. knowlesi lysate. The LOD of the assay from three technical replicates was 0.068% parasitaemia. The assay performance in detecting P. knowlesi was 83% sensitivity and 70% specificity with positive and negative predictive values of 74% and 80%, respectively. The anti-PkRAP-1 polyclonal antibodies did not cross-react with P. falciparum and healthy samples, but P. vivax by detecting all 12 samples.
INTERPRETATION CONCLUSION
PkRAP-1 has the potential as a biomarker for the development of a new diagnostic tool for P. knowlesi detection. Further studies need to be conducted to establish the full potential of the usage of anti-PkRAP-1 antibodies for P. knowlesi detection.
Topics: Plasmodium knowlesi; Enzyme-Linked Immunosorbent Assay; Animals; Malaria; Antibodies, Protozoan; Rabbits; Sensitivity and Specificity; Mice; Protozoan Proteins; Humans; Antigens, Protozoan; Blotting, Western; Limit of Detection
PubMed: 38922654
DOI: 10.4103/jvbd.jvbd_55_23