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Nithimethachoke T, Boonmak C, Morikawa M. A novel alkane monooxygenase evolved from a broken piece of ribonucleotide reductase in Geobacillus kaustophilus HTA426 isolated from Mariana Trench. Extremophiles 2024; 28:18. [PMID: 38353731 PMCID: PMC10867098 DOI: 10.1007/s00792-024-01332-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 12/30/2023] [Indexed: 02/16/2024]
Abstract
We have accidentally found that a thermophilic Geobacillus kaustophilus HTA426 is capable of degrading alkanes although it has no alkane oxygenating enzyme genes. Our experimental results revealed that a putative ribonucleotide reductase small subunit GkR2loxI (GK2771) gene encodes a novel heterodinuclear Mn-Fe alkane monooxygenase/hydroxylase. GkR2loxI protein can perform two-electron oxidations similar to homonuclear diiron bacterial multicomponent soluble methane monooxygenases. This finding not only answers a long-standing question about the substrate of the R2lox protein clade, but also expands our understanding of the vast diversity and new evolutionary lineage of the bacterial alkane monooxygenase/hydroxylase family.
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Affiliation(s)
- Tanasap Nithimethachoke
- Graduate School of Environmental Science, Hokkaido University, Kita-10 Nishi-5, Kita-ku, Sapporo, 060-0810, Japan
| | - Chanita Boonmak
- Department of Microbiology, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan Rd., Lat Yao, Chatuchak, Bangkok, 10900, Thailand
| | - Masaaki Morikawa
- Graduate School of Environmental Science, Hokkaido University, Kita-10 Nishi-5, Kita-ku, Sapporo, 060-0810, Japan.
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2
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Bechtold P, Wagner P, Hosch S, Gregorini M, Stark WJ, Gody JC, Kodia-Lenguetama ER, Pagonendji MS, Donfack OT, Phiri WP, García GA, Nsanzanbana C, Daubenberger CA, Schindler T, Vickos U. Development and evaluation of PlasmoPod: A cartridge-based nucleic acid amplification test for rapid malaria diagnosis and surveillance. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0001516. [PMID: 37756280 PMCID: PMC10529553 DOI: 10.1371/journal.pgph.0001516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 09/04/2023] [Indexed: 09/29/2023]
Abstract
Malaria surveillance is hampered by the widespread use of diagnostic tests with low sensitivity. Adequate molecular malaria diagnostics are often only available in centralized laboratories. PlasmoPod is a novel cartridge-based nucleic acid amplification test for rapid, sensitive, and quantitative detection of malaria parasites. PlasmoPod is based on reverse-transcription quantitative polymerase chain reaction (RT-qPCR) of the highly abundant Plasmodium spp. 18S ribosomal RNA/DNA biomarker and is run on a portable qPCR instrument which allows diagnosis in less than 30 minutes. Our analytical performance evaluation indicates that a limit-of-detection as low as 0.02 parasites/μL can be achieved and no cross-reactivity with other pathogens common in malaria endemic regions was observed. In a cohort of 102 asymptomatic individuals from Bioko Island with low malaria parasite densities, PlasmoPod accurately detected 83 cases, resulting in an overall detection rate of 81.4%. Notably, there was a strong correlation between the Cq values obtained from the reference RT-qPCR assay and those obtained from PlasmoPod. In an independent cohort, using dried blood spots from malaria symptomatic children living in the Central African Republic, we demonstrated that PlasmoPod outperforms malaria rapid diagnostic tests based on the PfHRP2 and panLDH antigens as well as thick blood smear microscopy. Our data suggest that this 30-minute sample-to-result RT-qPCR procedure is likely to achieve a diagnostic performance comparable to a standard laboratory-based RT-qPCR setup. We believe that the PlasmoPod rapid NAAT could enable widespread accessibility of high-quality and cost-effective molecular malaria surveillance data through decentralization of testing and surveillance activities, especially in elimination settings.
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Affiliation(s)
- Philippe Bechtold
- Institute for Chemical and Bioengineering, ETH Zurich, Zuerich, Switzerland
- Diaxxo AG, Zuerich, Switzerland
| | - Philipp Wagner
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Salome Hosch
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Michele Gregorini
- Institute for Chemical and Bioengineering, ETH Zurich, Zuerich, Switzerland
- Diaxxo AG, Zuerich, Switzerland
| | - Wendelin J. Stark
- Institute for Chemical and Bioengineering, ETH Zurich, Zuerich, Switzerland
- Diaxxo AG, Zuerich, Switzerland
| | - Jean Chrysostome Gody
- Paediatric Hospital and University Complex of Bangui, Bangui, Central African Republic
| | | | | | | | | | | | - Christian Nsanzanbana
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Claudia A. Daubenberger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Tobias Schindler
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ulrich Vickos
- Infectious and Tropical Diseases Unit, Department of Medicine, Amitié Hospital, Bangui, Central African Republic
- Microbiology and Diagnostic Immunology Unit, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy
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3
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Stabler TC, Dwivedi A, Shrestha B, Joshi S, Schindler T, Ouattara A, García GA, Daubenberger C, Silva JC. Gene Coverage Count and Classification (GC3): a locus sequence coverage assessment tool using short-read whole genome sequencing data, and its application to identify and classify histidine-rich protein 2 and 3 deletions in Plasmodium falciparum. Malar J 2022; 21:357. [PMID: 36447234 PMCID: PMC9706933 DOI: 10.1186/s12936-022-04376-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 11/10/2022] [Indexed: 11/30/2022] Open
Abstract
Abstract
Background
The ability of malaria rapid diagnostic tests (RDTs) to effectively detect active infections is being compromised by the presence of malaria strains with genomic deletions at the hrp2 and hrp3 loci, encoding the antigens most commonly targeted in diagnostics for Plasmodium falciparum detection. The presence of such deletions can be determined in publically available P. falciparum whole genome sequencing (WGS) datasets. A computational approach was developed and validated, termed Gene Coverage Count and Classification (GC3), to analyse genome-wide sequence coverage data and provide informative outputs to assess presence and coverage profile of a target locus in WGS data. GC3 was applied to detect deletions at hrp2 and hrp3 (hrp2/3) and flanking genes in different geographic regions and across time points.
Methods
GC3 uses Python and R scripts to extract locus read coverage metrics from mapped WGS data according to user-defined parameters and generates relevant tables and figures. GC3 was tested using WGS data for laboratory reference strains with known hrp2/3 genotypes, and its results compared to those of a hrp2/3-specific qPCR assay. Samples with at least 25% of coding region positions with zero coverage were classified as having a deletion. Publicly available sequence data was analysed and compared with published deletion frequency estimates.
Results
GC3 results matched the expected coverage of known laboratory reference strains. Agreement between GC3 and a hrp2/3-specific qPCR assay reported for 19/19 (100%) hrp2 deletions and 18/19 (94.7%) hrp3 deletions. Among Cambodian (n = 127) and Brazilian (n = 20) WGS datasets, which had not been previously analysed for hrp2/3 deletions, GC3 identified hrp2 deletions in three and four samples, and hrp3 deletions in 10 and 15 samples, respectively. Plots of hrp2/3 coding regions, grouped by year of sample collection, showed a decrease in median standardized coverage among Malawian samples (n = 150) suggesting the importance of a careful, properly controlled follow up to determine if an increase in frequency of deletions has occurred between 2007–2008 and 2014–2015. Among Malian (n = 90) samples, median standardized coverage was lower in 2002 than 2010, indicating widespread deletions present at the gene locus in 2002.
Conclusions
The GC3 tool accurately classified hrp2/3 deletions and provided informative tables and figures to analyse targeted gene coverage. GC3 is an appropriate tool when performing preliminary and exploratory assessment of locus coverage data.
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Schindler T, Deal AC, Fink M, Guirou E, Moser KA, Mwakasungula SM, Mihayo MG, Jongo SA, Chaki PP, Abdulla S, Valverde PCM, Torres K, Bijeri JR, Silva JC, Hoffman SL, Gamboa D, Tanner M, Daubenberger C. A multiplex qPCR approach for detection of pfhrp2 and pfhrp3 gene deletions in multiple strain infections of Plasmodium falciparum. Sci Rep 2019; 9:13107. [PMID: 31511562 PMCID: PMC6739368 DOI: 10.1038/s41598-019-49389-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/24/2019] [Indexed: 01/31/2023] Open
Abstract
The rapid and accurate diagnosis of Plasmodium falciparum malaria infection is an essential factor in malaria control. Currently, malaria diagnosis in the field depends heavily on using rapid diagnostic tests (RDTs) many of which detect circulating parasite-derived histidine-rich protein 2 antigen (PfHRP2) in capillary blood. P. falciparum strains lacking PfHRP2, due to pfhrp2 gene deletions, are an emerging threat to malaria control programs. The novel assay described here, named qHRP2/3-del, is well suited for high-throughput screening of P. falciparum isolates to identify these gene deletions. The qHRP2/3-del assay identified pfhrp2 and pfhrp3 deletion status correctly in 93.4% of samples with parasitemia levels higher than 5 parasites/µL when compared to nested PCR. The qHRP2/3-del assay can correctly identify pfhrp2 and pfhrp3 gene deletions in multiple strain co-infections, particularly prevalent in Sub-Saharan countries. Deployment of this qHRP2/3-del assay will provide rapid insight into the prevalence and potential spread of P. falciparum isolates that escape surveillance by RDTs.
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Affiliation(s)
- Tobias Schindler
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Anna C Deal
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Martina Fink
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Etienne Guirou
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Kara A Moser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Solomon M Mwakasungula
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Michael G Mihayo
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Said A Jongo
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Prosper P Chaki
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Salim Abdulla
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania
| | - Paulo C Manrique Valverde
- Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia & Instituto de Medicina Tropical, Alexander von Humboldt Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Katherine Torres
- Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia & Instituto de Medicina Tropical, Alexander von Humboldt Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Jose R Bijeri
- Equatorial Guinea Malaria Vaccine Initiative, Malabo, Equatorial Guinea
| | - Joana C Silva
- Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia & Instituto de Medicina Tropical, Alexander von Humboldt Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Dionicia Gamboa
- Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia & Instituto de Medicina Tropical, Alexander von Humboldt Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Marcel Tanner
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Claudia Daubenberger
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
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El Kouni MH. Pyrimidine metabolism in schistosomes: A comparison with other parasites and the search for potential chemotherapeutic targets. Comp Biochem Physiol B Biochem Mol Biol 2017; 213:55-80. [PMID: 28735972 PMCID: PMC5593796 DOI: 10.1016/j.cbpb.2017.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/29/2017] [Accepted: 07/03/2017] [Indexed: 12/18/2022]
Abstract
Schistosomes are responsible for the parasitic disease schistosomiasis, an acute and chronic parasitic ailment that affects >240 million people in 70 countries worldwide. It is the second most devastating parasitic disease after malaria. At least 200,000 deaths per year are associated with the disease. In the absence of the availability of vaccines, chemotherapy is the main stay for combating schistosomiasis. The antischistosomal arsenal is currently limited to a single drug, Praziquantel, which is quite effective with a single-day treatment and virtually no host-toxicity. Recently, however, the question of reduced activity of Praziquantel has been raised. Therefore, the search for alternative antischistosomal drugs merits the study of new approaches of chemotherapy. The rational design of a drug is usually based on biochemical and physiological differences between pathogens and host. Pyrimidine metabolism is an excellent target for such studies. Schistosomes, unlike most of the host tissues, require a very active pyrimidine metabolism for the synthesis of DNA and RNA. This is essential for the production of the enormous numbers of eggs deposited daily by the parasite to which the granulomas response precipitates the pathogenesis of schistosomiasis. Furthermore, there are sufficient differences between corresponding enzymes of pyrimidine metabolism from the host and the parasite that can be exploited to design specific inhibitors or "subversive substrates" for the parasitic enzymes. Specificities of pyrimidine transport also diverge significantly between parasites and their mammalian host. This review deals with studies on pyrimidine metabolism in schistosomes and highlights the unique characteristic of this metabolism that could constitute excellent potential targets for the design of safe and effective antischistosomal drugs. In addition, pyrimidine metabolism in schistosomes is compared with that in other parasites where studies on pyrimidine metabolism have been more elaborate, in the hope of providing leads on how to identify likely chemotherapeutic targets which have not been looked at in schistosomes.
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Affiliation(s)
- Mahmoud H El Kouni
- Department of Pharmacology and Toxicology, Center for AIDS Research, Comprehensive Cancer Center, General Clinical Research Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Factors mediating plastid dependency and the origins of parasitism in apicomplexans and their close relatives. Proc Natl Acad Sci U S A 2015; 112:10200-7. [PMID: 25717057 DOI: 10.1073/pnas.1423790112] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Apicomplexans are a major lineage of parasites, including causative agents of malaria and toxoplasmosis. How such highly adapted parasites evolved from free-living ancestors is poorly understood, particularly because they contain nonphotosynthetic plastids with which they have a complex metabolic dependency. Here, we examine the origin of apicomplexan parasitism by resolving the evolutionary distribution of several key characteristics in their closest free-living relatives, photosynthetic chromerids and predatory colpodellids. Using environmental sequence data, we describe the diversity of these apicomplexan-related lineages and select five species that represent this diversity for transcriptome sequencing. Phylogenomic analysis recovered a monophyletic lineage of chromerids and colpodellids as the sister group to apicomplexans, and a complex distribution of retention versus loss for photosynthesis, plastid genomes, and plastid organelles. Reconstructing the evolution of all plastid and cytosolic metabolic pathways related to apicomplexan plastid function revealed an ancient dependency on plastid isoprenoid biosynthesis, predating the divergence of apicomplexan and dinoflagellates. Similarly, plastid genome retention is strongly linked to the retention of two genes in the plastid genome, sufB and clpC, altogether suggesting a relatively simple model for plastid retention and loss. Lastly, we examine the broader distribution of a suite of molecular characteristics previously linked to the origins of apicomplexan parasitism and find that virtually all are present in their free-living relatives. The emergence of parasitism may not be driven by acquisition of novel components, but rather by loss and modification of the existing, conserved traits.
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