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Muema JM, Mutunga JM, Obonyo MA, Getahun MN, Mwakubambanya RS, Akala HM, Cheruiyot AC, Yeda RA, Juma DW, Andagalu B, Johnson JL, Roth AL, Bargul JL. Isoliensinine from Cissampelos pariera rhizomes exhibits potential gametocytocidal and anti-malarial activities against Plasmodium falciparum clinical isolates. Malar J 2023; 22:161. [PMID: 37208735 DOI: 10.1186/s12936-023-04590-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 05/15/2023] [Indexed: 05/21/2023] Open
Abstract
BACKGROUND The unmet demand for effective malaria transmission-blocking agents targeting the transmissible stages of Plasmodium necessitates intensive discovery efforts. In this study, a bioactive bisbenzylisoquinoline (BBIQ), isoliensinine, from Cissampelos pariera (Menispermaceae) rhizomes was identified and characterized for its anti-malarial activity. METHODS Malaria SYBR Green I fluorescence assay was performed to evaluate the in vitro antimalarial activity against D6, Dd2, and F32-ART5 clones, and immediate ex vivo (IEV) susceptibility for 10 freshly collected P. falciparum isolates. To determine the speed- and stage-of-action of isoliensinine, an IC50 speed assay and morphological analyses were performed using synchronized Dd2 asexuals. Gametocytocidal activity against two culture-adapted gametocyte-producing clinical isolates was determined using microscopy readouts, with possible molecular targets and their binding affinities deduced in silico. RESULTS Isoliensinine displayed a potent in vitro gametocytocidal activity at mean IC50gam values ranging between 0.41 and 0.69 µM for Plasmodium falciparum clinical isolates. The BBIQ compound also inhibited asexual replication at mean IC50Asexual of 2.17 µM, 2.22 µM, and 2.39 µM for D6, Dd2 and F32-ART5 respectively, targeting the late-trophozoite to schizont transition. Further characterization demonstrated a considerable immediate ex vivo potency against human clinical isolates at a geometric mean IC50IEV = 1.433 µM (95% CI 0.917-2.242). In silico analyses postulated a probable anti-malarial mechanism of action by high binding affinities for four mitotic division protein kinases; Pfnek1, Pfmap2, Pfclk1, and Pfclk4. Additionally, isoliensinine was predicted to possess an optimal pharmacokinetics profile and drug-likeness properties. CONCLUSION These findings highlight considerable grounds for further exploration of isoliensinine as an amenable scaffold for malaria transmission-blocking chemistry and target validation.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya.
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya.
| | - James M Mutunga
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
- Department of Biological Sciences, School of Pure and Applied Sciences, Mount Kenya University, Thika, Kenya
- School of Engineering Design, Technology and Professional Programs, Pennsylvania State University, University Park, PA, 16802, USA
| | - Meshack A Obonyo
- Department of Biochemistry and Molecular Biology, Egerton University, Egerton, Kenya
| | - Merid N Getahun
- International Centre of Insect Physiology and Ecology (Icipe), Nairobi, Kenya
| | | | - Hoseah M Akala
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Agnes C Cheruiyot
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Redemptah A Yeda
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Dennis W Juma
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Ben Andagalu
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Jaree L Johnson
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Amanda L Roth
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya.
- International Centre of Insect Physiology and Ecology (Icipe), Nairobi, Kenya.
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Abstract
The scientific community worldwide has realized that malaria elimination will not be possible without development of safe and effective transmission-blocking interventions. Primaquine, the only WHO recommended transmission-blocking drug, is not extensively utilized because of the toxicity issues in G6PD deficient individuals. Therefore, there is an urgent need to develop novel therapeutic interventions that can target malaria parasites and effectively block transmission. But at first, it is imperative to unravel the existing portfolio of transmission-blocking drugs. This review highlights transmission-blocking potential of current antimalarial drugs and drugs that are in various stages of clinical development. The collective analysis of the relationships between the structure and the activity of transmission-blocking drugs is expected to help in the design of new transmission-blocking antimalarials.
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Martin RE. The transportome of the malaria parasite. Biol Rev Camb Philos Soc 2019; 95:305-332. [PMID: 31701663 DOI: 10.1111/brv.12565] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 12/15/2022]
Abstract
Membrane transport proteins, also known as transporters, control the movement of ions, nutrients, metabolites, and waste products across the membranes of a cell and are central to its biology. Proteins of this type also serve as drug targets and are key players in the phenomenon of drug resistance. The malaria parasite has a relatively reduced transportome, with only approximately 2.5% of its genes encoding transporters. Even so, assigning functions and physiological roles to these proteins, and ascertaining their contributions to drug action and drug resistance, has been very challenging. This review presents a detailed critique and synthesis of the disruption phenotypes, protein subcellular localisations, protein functions (observed or predicted), and links to antimalarial drug resistance for each of the parasite's transporter genes. The breadth and depth of the gene disruption data are particularly impressive, with at least one phenotype determined in the parasite's asexual blood stage for each transporter gene, and multiple phenotypes available for 76% of the genes. Analysis of the curated data set revealed there to be relatively little redundancy in the Plasmodium transportome; almost two-thirds of the parasite's transporter genes are essential or required for normal growth in the asexual blood stage of the parasite, and this proportion increased to 78% when the disruption phenotypes available for the other parasite life stages were included in the analysis. These observations, together with the finding that 22% of the transportome is implicated in the parasite's resistance to existing antimalarials and/or drugs within the development pipeline, indicate that transporters are likely to serve, or are already serving, as drug targets. Integration of the different biological and bioinformatic data sets also enabled the selection of candidates for transport processes known to be essential for parasite survival, but for which the underlying proteins have thus far remained undiscovered. These include potential transporters of pantothenate, isoleucine, or isopentenyl diphosphate, as well as putative anion-selective channels that may serve as the pore component of the parasite's 'new permeation pathways'. Other novel insights into the parasite's biology included the identification of transporters for the potential development of antimalarial treatments, transmission-blocking drugs, prophylactics, and genetically attenuated vaccines. The syntheses presented herein set a foundation for elucidating the functions and physiological roles of key members of the Plasmodium transportome and, ultimately, to explore and realise their potential as therapeutic targets.
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Affiliation(s)
- Rowena E Martin
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
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Rajendran V, Singh C, Ghosh PC. Improved efficacy of doxycycline in liposomes against Plasmodium falciparum in culture and Plasmodium berghei infection in mice. Can J Physiol Pharmacol 2018; 96:1145-1152. [PMID: 30075085 DOI: 10.1139/cjpp-2018-0067] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The rate at which Plasmodium falciparum is developing resistance to clinically used antimalarial drugs is alarming. Therefore, there is a compelling need to develop an efficient drug delivery system to improve the efficacy of existing antimalarial agents and circumvent drug resistance. Here, we report the antibacterial drug doxycycline (DOXY) in liposomal formulations exhibits enhanced antiplasmodial activity against blood stage forms of P. falciparum (3D7) in culture and established Plasmodium berghei NK-65 infection in murine model. Parasite killing on blood stage forms in culture was determined by a radiolabeled [3H] hypoxanthine incorporation assay and infected erythrocytes stained with Giemsa were counted using microscopy in vivo. The 50% inhibitory concentration (IC50) of DOXY-stearylamine liposome (IC50 0.36 μM) and DOXY-SPC:Chol-liposome (IC50 0.85 μM) exhibited marked growth inhibition of parasites compared with free DOXY (IC50 14 μM), with minimal toxicity to normal erythrocytes. Administration of polyethylene glycol distearoyl phosphatidylethanolamine-methoxy-polyethylene glycol2000 (DSPE-mPEG-2000) coated liposomes loaded with DOXY at 2.5 mg/kg per day resulted in efficacious killing of blood parasites with improved survival in mice relative to the free drug in both chloroquine sensitive and resistant strains of P. berghei infection. This is the first report to demonstrate that DOXY in liposomal system has immense chemotherapeutic potential against plasmodial infections at lower dosages.
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Affiliation(s)
- Vinoth Rajendran
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.,Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Chanchal Singh
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.,Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Prahlad C Ghosh
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.,Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
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Delayed Onset of Plasmodium falciparum Malaria after Doxycycline Prophylaxis in a Soldier Returning from the Central African Republic. Antimicrob Agents Chemother 2016; 60:2592-3. [PMID: 26856842 DOI: 10.1128/aac.01858-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Madamet M, Gaillard T, Velut G, Ficko C, Houzé P, Bylicki C, Mérat S, Houzé S, Taudon N, Michel R, Pasquier P, Rapp C, Pradines B. Malaria Prophylaxis Failure with Doxycycline, Central African Republic, 2014. Emerg Infect Dis 2016. [PMID: 26196738 PMCID: PMC4517722 DOI: 10.3201/eid2108.150524] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Gaillard T, Madamet M, Pradines B. Tetracyclines in malaria. Malar J 2015; 14:445. [PMID: 26555664 PMCID: PMC4641395 DOI: 10.1186/s12936-015-0980-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/02/2015] [Indexed: 11/12/2022] Open
Abstract
Malaria, a parasite vector-borne disease, is one of the greatest health threats in tropical regions, despite the availability of malaria chemoprophylaxis. The emergence and rapid extension of Plasmodium falciparum resistance to various anti-malarial drugs has gradually limited the number of potential malaria therapeutics available to clinicians. In this context, doxycycline, a synthetically derived tetracycline, constitutes an interesting alternative for malaria treatment and prophylaxis. Doxycycline is a slow-acting blood schizontocidal agent that is highly effective at preventing malaria. In areas with chloroquine and multidrug-resistant P. falciparum parasites, doxycycline has already been successfully used in combination with quinine to treat malaria, and it has been proven to be effective and well-tolerated. Although not recommended for pregnant women and children younger than 8 years of age, severe adverse effects are rarely reported. In addition, resistance to doxycycline is rarely described. Prophylactic and clinical failures of doxycycline have been associated with both inadequate doses and poor patient compliance. The effects of tetracyclines on parasites are not completely understood. A better comprehension of the mechanisms underlying drug resistance would facilitate the identification of molecular markers of resistance to predict and survey the emergence of resistance.
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Affiliation(s)
- Tiphaine Gaillard
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM 63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, Marseille, France. .,Fédération des Laboratoires, Hôpital d'Instruction des Armées Saint Anne, Toulon, France.
| | - Marylin Madamet
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM 63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, Marseille, France. .,Equipe Résidente de Recherche en Infectiologie Tropicale, Institut de Recherche Biomédicale des Armées, Hôpital d'Instruction des Armées, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France.
| | - Bruno Pradines
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM 63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France. .,Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France.
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Gaillard T, Wurtz N, Houzé S, Sriprawat K, Wangsing C, Hubert V, Lebras J, Nosten F, Briolant S, Pradines B. Absence of association between Plasmodium falciparum small sub-unit ribosomal RNA gene mutations and in vitro decreased susceptibility to doxycycline. Malar J 2015; 14:348. [PMID: 26377329 PMCID: PMC4574345 DOI: 10.1186/s12936-015-0878-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 08/29/2015] [Indexed: 02/16/2023] Open
Abstract
Background Doxycycline is an antibiotic used in combination with quinine or artesunate for malaria treatment or alone for malaria chemoprophylaxis. Recently, one prophylactic failure has been reported, and several studies have highlighted in vitro doxycycline decreased susceptibility in Plasmodium falciparum isolates from different areas. The genetic markers that contribute to detecting and monitoring the susceptibility of P. falciparum to doxycycline, the pfmdt and pftetQ genes, have recently been identified. However, these markers are not sufficient to explain in vitro decreased susceptibility of P. falciparum to doxycycline. In this paper, the association between polymorphism of the small sub-unit ribosomal RNA apicoplastic gene pfssrRNA (PFC10_API0057) and in vitro susceptibilities of P. falciparum isolates to doxycycline were investigated. Methods Doxycycline IC50 determinations using the hypoxanthine uptake inhibition assay were performed on 178 African and Thai P. falciparum isolates. The polymorphism of pfssrRNA was investigated in these samples by standard PCR followed by sequencing. Results No point mutations were found in pfssrRNA in the Thai or African isolates, regardless of the determined IC50 values. Conclusions The pfssrRNA gene is not associated with in vitro decreased susceptibility of P. falciparum to doxycycline. Identifying new in vitro molecular markers associated with reduced susceptibility is needed, to survey the emergence of doxycycline resistance.
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Affiliation(s)
- Tiphaine Gaillard
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Fédération des Laboratoires, Hôpital d'Instruction des Armées Saint Anne, Toulon, France.
| | - Nathalie Wurtz
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France.
| | - Sandrine Houzé
- Laboratoire de Parasitologie-Mycologie, Centre National de Référence du Paludisme, APHP, Hôpital Bichat-Claude Bernard, Paris, France. .,IRD UMR216, Mère et enfant face aux infections tropicales, Paris, France. .,PRES Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Paris, France.
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sod, Thailand.
| | - Chirapat Wangsing
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sod, Thailand.
| | - Véronique Hubert
- Laboratoire de Parasitologie-Mycologie, Centre National de Référence du Paludisme, APHP, Hôpital Bichat-Claude Bernard, Paris, France. .,PRES Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Paris, France.
| | - Jacques Lebras
- Laboratoire de Parasitologie-Mycologie, Centre National de Référence du Paludisme, APHP, Hôpital Bichat-Claude Bernard, Paris, France. .,IRD UMR216, Mère et enfant face aux infections tropicales, Paris, France. .,PRES Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Paris, France.
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sod, Thailand. .,Centre for Tropical Medicine, University of Oxford, Oxford, UK.
| | - Sébastien Briolant
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Direction Inter-Armées du Service de Santé, Cayenne, French Guiana. .,Laboratoire de Parasitologie, Institut Pasteur de la Guyane, Cayenne, French Guiana.
| | - Bruno Pradines
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France. .,Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France.
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Mura M, Briolant S, Donato D, Volney B, Pelleau S, Musset L, Legrand E. Absence of correlation between ex vivo susceptibility to doxycycline and pfteQ-pfmdt gene polymorphism in French Guiana. Malar J 2015. [PMID: 26206143 PMCID: PMC4513625 DOI: 10.1186/s12936-015-0788-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background In French Guiana, doxycycline is used for both chemoprophylaxis and the treatment of malaria. The presence of isolates with reduced ex vivo susceptibility to doxycycline in French Guiana makes it critical to identify any genetic determinants contributing to the chemosusceptibility level of Plasmodium falciparum to doxycycline, such as pfmdt and pftetQ, which were recently identified as potential molecular markers in African isolates. Methods A Bayesian statistical approach was used to define different ex vivo doxycycline phenotypes. The pfmdt and pftetQ gene copy numbers were quantified by quantitative real-time polymerase chain reaction in 129 P. falciparum isolates collected between 2000 and 2010, and pftetQ, pfrps7, pfssurRNA, and pflsurRNA sequences were analysed after amplification by polymerase chain reaction. Results PftetQ and pfmdt copy numbers were not associated with reduced susceptibility to doxycycline in P. falciparum within French Guiana. Sequence analysis of the genes revealed five known single nucleotide polymorphisms. Three new SNPs were identified
in the apicoplast ribosomal RNA long sub-unit (pflsurRNA): C740T, A1875C and A1875T. These polymorphisms were not associated with reduced chemosusceptibility to doxycycline. Conclusions The present study does not validate pfmdt and pftetQ genes as molecular markers of decreased susceptibility to doxycycline in P. falciparum isolates in French Guiana.
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Affiliation(s)
- Marie Mura
- Laboratoire de Parasitologie, Centre National de Référence du Paludisme aux Antilles, Guyane, Institut Pasteur de la Guyane, Cayenne Cedex, France. .,Direction Interarmées du Service de Santé en Guyane, Quartier La Madeleine, BP 6019, 97306, Cayenne Cedex, French Guiana.
| | - Sébastien Briolant
- Laboratoire de Parasitologie, Centre National de Référence du Paludisme aux Antilles, Guyane, Institut Pasteur de la Guyane, Cayenne Cedex, France. .,Direction Interarmées du Service de Santé en Guyane, Quartier La Madeleine, BP 6019, 97306, Cayenne Cedex, French Guiana. .,Institut de Recherche Biomédicale des Armées, BP 73, 91223, Brétigny sur Orge Cedex, France.
| | - Damien Donato
- Laboratoire de Parasitologie, Centre National de Référence du Paludisme aux Antilles, Guyane, Institut Pasteur de la Guyane, Cayenne Cedex, France.
| | - Béatrice Volney
- Laboratoire de Parasitologie, Centre National de Référence du Paludisme aux Antilles, Guyane, Institut Pasteur de la Guyane, Cayenne Cedex, France.
| | - Stéphane Pelleau
- Laboratoire de Parasitologie, Centre National de Référence du Paludisme aux Antilles, Guyane, Institut Pasteur de la Guyane, Cayenne Cedex, France.
| | - Lise Musset
- Laboratoire de Parasitologie, Centre National de Référence du Paludisme aux Antilles, Guyane, Institut Pasteur de la Guyane, Cayenne Cedex, France.
| | - Eric Legrand
- Laboratoire de Parasitologie, Centre National de Référence du Paludisme aux Antilles, Guyane, Institut Pasteur de la Guyane, Cayenne Cedex, France. .,Unité de Recherche Génétique et Génomique des Insectes Vecteurs, Institut Pasteur, 25-28 rue du Dr Roux, 75724, Paris Cedex 15, France.
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Molecular Markers and In Vitro Susceptibility to Doxycycline in Plasmodium falciparum Isolates from Thailand. Antimicrob Agents Chemother 2015; 59:5080-3. [PMID: 26055380 DOI: 10.1128/aac.00345-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 06/02/2015] [Indexed: 11/20/2022] Open
Abstract
Determinations of doxycycline 50% inhibitory concentrations (IC50) for 620 isolates from northwest Thailand were performed via the isotopic method, and the data were analyzed by the Bayesian method and distributed into two populations (mean IC50s of 13.15 μM and 31.60 μM). There was no significant difference between the group with low IC50s versus the group with high IC50s with regard to copy numbers of the Plasmodium falciparum tetQ (pftetQ) gene (P = 0.11) or pfmdt gene (P = 0.87) or the number of PfTetQ KYNNNN repeats (P = 0.72).
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