1
|
Gendrot M, Madamet M, Mosnier J, Fonta I, Amalvict R, Benoit N, Briolant S, Pradines B. Baseline and multinormal distribution of ex vivo susceptibilities of Plasmodium falciparum to methylene blue in Africa, 2013-18. J Antimicrob Chemother 2021; 75:2141-2148. [PMID: 32407538 DOI: 10.1093/jac/dkaa174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 04/03/2020] [Accepted: 04/06/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Plasmodium falciparum resistance to most antimalarial compounds has emerged in Southeast Asia and spread to Africa. In this context, the development of new antimalarial drugs is urgent. OBJECTIVES To determine the baseline in vitro activity of methylene blue (Proveblue®) on African isolates and to determine whether parasites have different phenotypes of susceptibility to methylene blue. METHODS Ex vivo susceptibility to methylene blue was measured for 609 P. falciparum isolates of patients hospitalized in France for malaria imported from Africa. A Bayesian statistical analysis was designed to describe the distribution of median effective concentration (EC50) estimates. RESULTS The EC50 ranged from 0.16 to 87.2 nM with a geometric mean of 7.17 nM (95% CI = 6.21-8.13). The 609 EC50 values were categorized into four components: A (mean = 2.5 nM; 95% CI = 2.28-2.72), B (mean = 7.44 nM; 95% CI = 7.07-7.81), C (mean = 16.29 nM; 95% CI = 15.40-17.18) and D (mean = 38.49 nM; 95% CI = 34.14-42.84). The threshold value for in vitro reduced susceptibility to methylene blue was estimated at 35 nM using the geometric mean of EC50 plus 2 SDs of the 609 isolates. This cut-off also corresponds to the lower limit of the 95% CI of the methylene blue EC50 of component D. Thirty-five isolates (5.7%) displayed EC50 values above this threshold. CONCLUSIONS Methylene blue exerts a promising efficacy against P. falciparum and is a potential partner for triple combinations.
Collapse
Affiliation(s)
- Mathieu Gendrot
- Unite Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France.,Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, Marseille, France.,IHU Méditerranée Infection, Marseille, France
| | - Marylin Madamet
- Unite Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France.,Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre National de Référence du Paludisme, Marseille, France
| | - Joel Mosnier
- Unite Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France.,Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre National de Référence du Paludisme, Marseille, France
| | - Isabelle Fonta
- Unite Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France.,Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre National de Référence du Paludisme, Marseille, France
| | - Rémy Amalvict
- Unite Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France.,Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre National de Référence du Paludisme, Marseille, France
| | - Nicolas Benoit
- Unite Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France.,Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre National de Référence du Paludisme, Marseille, France
| | - Sébastien Briolant
- Unite Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France.,Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, Marseille, France.,IHU Méditerranée Infection, Marseille, France
| | - Bruno Pradines
- Unite Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France.,Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre National de Référence du Paludisme, Marseille, France
| |
Collapse
|
2
|
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
|
3
|
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
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
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.
Collapse
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.
| | | |
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
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).
Collapse
|
8
|
Pascual A, Madamet M, Briolant S, Gaillard T, Amalvict R, Benoit N, Travers D, Pradines B. Multinormal in vitro distribution of Plasmodium falciparum susceptibility to piperaquine and pyronaridine. Malar J 2015; 14:49. [PMID: 25848972 PMCID: PMC4323025 DOI: 10.1186/s12936-015-0586-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 01/26/2015] [Indexed: 12/27/2022] Open
Abstract
Background In 2002, the World Health Organization recommended that artemisinin-based combination therapy (ACT) be used to treat uncomplicated malaria. Dihydroartemisinin-piperaquine and artesunate-pyronaridine are two of these new combinations. The aim of the present work was to assess the distribution of the in vitro values of pyronaridine (PND) and piperaquine (PPQ) and to define a cut-off for reduced susceptibility for the two anti-malarial drugs. Methods The distribution and range of the 50% inhibitory concentration values (IC50) of PND and PPQ were determined for 313 isolates obtained between 2008 and 2012 from patients hospitalized in France for imported malaria. The statistical Bayesian analysis was designed to answer the specific question of whether Plasmodium falciparum has different phenotypes of susceptibility to PND and PPQ. Results The PND IC50 values ranged from 0.6 to 84.6 nM, with a geometric mean of 21.1 ± 16.0 nM (standard deviation). These values were classified into three components. The PPQ IC50 values ranged from 9.8 to 217.3 nM, and the geometric mean was 58.0 ± 34.5 nM. All 313 PPQ values were classified into four components. Isolates with IC50 values greater than 60 nM or four-fold greater than 3D7 IC50 are considered isolates that have reduced susceptibility to PND and those with IC50 values greater than 135 nM or 2.3-fold greater than 3D7 IC50 are considered isolates that have reduced susceptibility to PPQ. Conclusion The existence of at least three phenotypes for PND and four phenotypes for PPQ was demonstrated. Based on the cut-off values, 18 isolates (5.8%) and 13 isolates (4.2%) demonstrated reduced susceptibility to PND and PPQ, respectively.
Collapse
|
9
|
Achieng AO, Ingasia LA, Juma DW, Cheruiyot AC, Okudo CA, Yeda RA, Cheruiyot J, Akala HM, Johnson J, Andangalu B, Eyase F, Jura WGZO, Kamau E. Reduced in vitro doxycycline susceptibility in plasmodium falciparum field isolates from Kenya is associated with PfTetQ KYNNNN sequence polymorphism. Antimicrob Agents Chemother 2014; 58:5894-9. [PMID: 25070109 PMCID: PMC4187988 DOI: 10.1128/aac.02788-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 07/18/2014] [Indexed: 11/20/2022] Open
Abstract
Doxycycline is widely used for malaria prophylaxis by international travelers. However, there is limited information on doxycycline efficacy in Kenya, and genetic polymorphisms associated with reduced efficacy are not well defined. In vitro doxycycline susceptibility profiles for 96 Plasmodium falciparum field isolates from Kenya were determined. Genetic polymorphisms were assessed in P. falciparum metabolite drug transporter (Pfmdt) and P. falciparum GTPase tetQ (PftetQ) genes. Copy number variation of the gene and the number of KYNNNN amino acid motif repeats within the protein encoded by PftetQ were determined. Reduced in vitro susceptibility to doxycycline was defined by 50% inhibitory concentrations (IC50s) of ≥35,000 nM. The odds ratio (OR) of having 2 PfTetQ KYNNNN amino acid repeats in isolates with IC50s of >35,000 nM relative to those with IC50s of <35,000 nM is 15 (95% confidence interval [CI], 3.0 to 74.3; P value of <0.0002). Isolates with 1 copy of the Pfmdt gene had a median IC50 of 6,971 nM, whereas those with a Pfmdt copy number of >1 had a median IC50 of 9,912 nM (P = 0.0245). Isolates with 1 copy of PftetQ had a median IC50 of 6,370 nM, whereas isolates with a PftetQ copy number of >1 had a median IC50 of 3,422 nM (P < 0.0007). Isolates with 2 PfTetQ KYNNNN motif repeats had a median IC50 of 26,165 nM, whereas isolates with 3 PfTetQ KYNNNN repeats had a median IC50 of 3,352 nM (P = 0.0023). PfTetQ sequence polymorphism is associated with a reduced doxycycline susceptibility phenotype in Kenyan isolates and is a potential marker for susceptibility testing.
Collapse
Affiliation(s)
- Angela O Achieng
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya Department of Zoology, School of Biological and Physical Sciences, Maseno University, Maseno, Kenya
| | - Luiser A Ingasia
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Dennis W Juma
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Agnes C Cheruiyot
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya Department of Zoology, School of Biological and Physical Sciences, Maseno University, Maseno, Kenya
| | - Charles A Okudo
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Redemptah A Yeda
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Jelagat Cheruiyot
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Hoseah M Akala
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Jacob Johnson
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Ben Andangalu
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Fredrick Eyase
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| | - Walter G Z O Jura
- Department of Zoology, School of Biological and Physical Sciences, Maseno University, Maseno, Kenya
| | - Edwin Kamau
- Department of Emerging Infectious Diseases-Global Emerging Infections Surveillance and Response System (DEID-GEIS) Program, United States Army Medical Research Unit-Kenya (USAMRU-K), Kenya Medical Research Institute (KEMRI)-Walter Reed Project, Kisumu, Kenya
| |
Collapse
|
10
|
Migliani R, Pradines B, Michel R, Aoun O, Dia A, Deparis X, Rapp C. Malaria control strategies in French armed forces. Travel Med Infect Dis 2014; 12:307-17. [PMID: 25069406 DOI: 10.1016/j.tmaid.2014.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 05/11/2014] [Accepted: 05/13/2014] [Indexed: 10/25/2022]
Abstract
Each year, 40,000 French soldiers deploy or travel through malaria-endemic areas. Despite the effective control measures that were successively implemented, malaria remains a public health concern in French armed forces with several important outbreaks and one lethal case every two years. This article describes the malaria control strategy in French armed forces which is based on three combined strategies: i) Anopheles vector control to prevent infection with the implementation of personal protection against vectors (PPAV) adapted to the field living conditions of the troops. ii) Chemoprophylaxis (CP) to prevent the disease based on prescription of effective and well tolerated doxycycline. iii) Management of cases through early diagnosis and appropriate treatment to prevent death. In isolated conditions in endemic areas, rapid diagnosis tests (RDT) are used as first-line tests by military doctors. Treatment of uncomplicated Plasmodium falciparum (P. falciparum) malaria is based either on the piperaquine tetraphosphate-dihydroartemisinin association since 2013, or on the atovaquone-proguanil association. First-line treatment of severe P. falciparum malaria is based on IV artesunate. These measures are associated with constant education of the military, epidemiological surveillance of malaria cases and monitoring of parasite chemosensitivity.
Collapse
Affiliation(s)
| | - B Pradines
- Institut de recherche biomédicale des armées, Brétigny-sur-Orge, France; Aix Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France
| | - R Michel
- Centre d'épidémiologie et de santé publique des armées, Marseille, France
| | - O Aoun
- Service des maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, Saint-Mandé, France
| | - A Dia
- Centre d'épidémiologie et de santé publique des armées, Marseille, France
| | - X Deparis
- Ecole du Val de Grâce, Paris, France; Centre d'épidémiologie et de santé publique des armées, Marseille, France
| | - C Rapp
- Ecole du Val de Grâce, Paris, France; Service des maladies infectieuses et tropicales, Hôpital d'instruction des armées Bégin, Saint-Mandé, France
| |
Collapse
|
11
|
Quashie NB, Duah NO, Abuaku B, Quaye L, Ayanful-Torgby R, Akwoviah GA, Kweku M, Johnson JD, Lucchi NW, Udhayakumar V, Duplessis C, Kronmann KC, Koram KA. A SYBR Green 1-based in vitro test of susceptibility of Ghanaian Plasmodium falciparum clinical isolates to a panel of anti-malarial drugs. Malar J 2013; 12:450. [PMID: 24341604 PMCID: PMC3878558 DOI: 10.1186/1475-2875-12-450] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 12/10/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Based on report of declining efficacy of chloroquine, Ghana shifted to the use of artemisinin-based combination therapy (ACT) in 2005 as the first-line anti-malarial drug. Since then, there has not been any major evaluation of the efficacy of anti-malarial drugs in Ghana in vitro. The sensitivity of Ghanaian Plasmodium falciparum isolates to anti-malarial drugs was, therefore, assessed and the data compared with that obtained prior to the change in the malaria treatment policy. METHODS A SYBR Green 1 fluorescent-based in vitro drug sensitivity assay was used to assess the susceptibility of clinical isolates of P. falciparum to a panel of 12 anti-malarial drugs in three distinct eco-epidemiological zones in Ghana. The isolates were obtained from children visiting health facilities in sentinel sites located in Hohoe, Navrongo and Cape Coast municipalities. The concentration of anti-malarial drug inhibiting parasite growth by 50% (IC50) for each drug was estimated using the online program, ICEstimator. RESULTS Pooled results from all the sentinel sites indicated geometric mean IC50 values of 1.60, 3.80, 4.00, 4.56, 5.20, 6.11, 10.12, 28.32, 31.56, 93.60, 107.20, and 8952.50 nM for atovaquone, artesunate, dihydroartemisin, artemether, lumefantrine, amodiaquine, mefloquine, piperaquine, chloroquine, tafenoquine, quinine, and doxycycline, respectively. With reference to the literature threshold value indicative of resistance, the parasites showed resistance to all the test drugs except the artemisinin derivatives, atovaquone and to a lesser extent, lumefantrine. There was nearly a two-fold decrease in the IC50 value determined for chloroquine in this study compared to that determined in 2004 (57.56 nM). This observation is important, since it suggests a significant improvement in the efficacy of chloroquine, probably as a direct consequence of reduced drug pressure after cessation of its use. Compared to that measured prior to the change in treatment policy, significant elevation of artesunate IC50 value was observed. The results also suggest the existence of possible cross-resistance among some of the test drugs. CONCLUSION Ghanaian P. falciparum isolates, to some extent, have become susceptible to chloroquine in vitro, however the increasing trend in artesunate IC50 value observed should be of concern. Continuous monitoring of ACT in Ghana is recommended.
Collapse
Affiliation(s)
- Neils B Quashie
- Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Gaillard T, Briolant S, Houzé S, Baragatti M, Wurtz N, Hubert V, Lavina M, Pascual A, Travaillé C, Le Bras J, Pradines B. PftetQ and pfmdt copy numbers as predictive molecular markers of decreased ex vivo doxycycline susceptibility in imported Plasmodium falciparum malaria. Malar J 2013; 12:414. [PMID: 24225377 PMCID: PMC3831056 DOI: 10.1186/1475-2875-12-414] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 11/10/2013] [Indexed: 11/18/2022] Open
Abstract
Background The objective of this study was to evaluate the distribution of a series of independent doxycycline inhibitory concentration 50% (IC50) values to validate the trimodal distribution previously described and to validate the use of the pftetQ and pfmdt genes as molecular markers of decreased in vitro doxycycline susceptibility in Plasmodium falciparum malaria. Methods Doxycycline IC50 values, from 484 isolates obtained at the French National Reference Centre for Imported Malaria (Paris) between January 2006 and December 2010, were analysed for the first time by a Bayesian mixture modelling approach to distinguish the different in vitro phenotypic groups by their IC50 values. Quantitative real-time polymerase chain reaction was used to evaluate the pftetQ and pfmdt copy numbers of 89 African P. falciparum isolates that were randomly chosen from the phenotypic groups. Results The existence of at least three doxycycline phenotypes was demonstrated. The mean doxycycline IC50 was significantly higher in the group with a pftetQ copy number >1 compared to the group with a pftetQ copy number = 1 (33.17 μM versus 17.23 μM) and the group with a pfmdt copy number >1 (28.28 μM versus 16.11 μM). There was a significant difference between the combined low and medium doxycycline IC50 group and the high IC50 group in terms of the per cent of isolates with one or more copy numbers of the pftetQ gene (0% versus 20.69%) or pfmdt gene (8.33% versus 37.93%). In the logistic regression model, the pfmdt and pftetQ copy numbers >1 (odds ratio = 4.65 and 11.47) were independently associated with the high IC50 group. Conclusions Copy numbers of pftetQ and pfmdt are potential predictive molecular markers of decreased susceptibility to doxycycline.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Bruno Pradines
- Unité de Parasitologie, Institut de Recherche Biomédicale des Armées, Marseille, France.
| | | |
Collapse
|
13
|
Rosenthal PJ. The interplay between drug resistance and fitness in malaria parasites. Mol Microbiol 2013; 89:1025-38. [PMID: 23899091 DOI: 10.1111/mmi.12349] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2013] [Indexed: 12/01/2022]
Abstract
Controlling the spread of antimalarial drug resistance, especially resistance of Plasmodium falciparum to artemisinin-based combination therapies, is a high priority. Available data indicate that, as with other microorganisms, the spread of drug-resistant malaria parasites is limited by fitness costs that frequently accompany resistance. Resistance-mediating polymorphisms in malaria parasites have been identified in putative drug transporters and in target enzymes. The impacts of these polymorphisms on parasite fitness have been characterized in vitro and in animal models. Additional insights have come from analyses of samples from clinical studies, both evaluating parasites under different selective pressures and determining the clinical consequences of infection with different parasites. With some exceptions, resistance-mediating polymorphisms lead to malaria parasites that, compared with wild type, grow less well in culture and in animals, and are replaced by wild type when drug pressure diminishes in the clinical setting. In some cases, the fitness costs of resistance may be offset by compensatory mutations that increase virulence or changes that enhance malaria transmission. However, not enough is known about effects of resistance mediators on parasite fitness. A better appreciation of the costs of fitness-mediating mutations will facilitate the development of optimal guidelines for the treatment and prevention of malaria.
Collapse
Affiliation(s)
- Philip J Rosenthal
- Department of Medicine, University of California, San Francisco, CA, 94143, USA
| |
Collapse
|
14
|
Fall B, Pascual A, Sarr FD, Wurtz N, Richard V, Baret E, Diémé Y, Briolant S, Bercion R, Wade B, Tall A, Pradines B. Plasmodium falciparum susceptibility to anti-malarial drugs in Dakar, Senegal, in 2010: an ex vivo and drug resistance molecular markers study. Malar J 2013; 12:107. [PMID: 23510258 PMCID: PMC3606842 DOI: 10.1186/1475-2875-12-107] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 03/10/2013] [Indexed: 11/18/2022] Open
Abstract
Background In 2006, the Senegalese National Malaria Control Programme recommended artemisinin-based combination therapy (ACT) as the first-line treatment for uncomplicated malaria. Since the introduction of ACT, there have been very few reports on the level of resistance of P. falciparum to anti-malarial drugs. To determine whether parasite susceptibility has been affected by the new anti-malarial policies, an ex vivo susceptibility and drug resistance molecular marker study was conducted on local isolates obtained from the Centre de santé Elizabeth Diouf (Médina, Dakar, Senegal). Methods The prevalence of genetic polymorphisms in genes associated with anti-malarial drug resistance, i.e., pfcrt, pfdhfr, pfdhps and pfmdr1, were evaluated for a panel of 165 isolates collected from patients recruited from 17 August 2010 to 6 January 2011. The malaria isolates were assessed for susceptibility to chloroquine (CQ); quinine (QN); monodesethylamodiaquine (MDAQ), the active metabolite of amodiaquine; mefloquine (MQ); lumefantrine (LMF); dihydroartemisinin (DHA), the active metabolite of artemisinin derivatives; and doxycycline (DOX) using the Plasmodium lactate dehydrogenase (pLDH) ELISA. Results The prevalence of the in vitro resistant isolates, or isolates with reduced susceptibility, was 62.1% for MQ, 24.2% for CQ, 10.3% for DOX, 11.8% MDAQ, 9.7% for QN, 2.9% for LMF and 0% for DHA. The Pfcrt 76T mutation was identified in 43.6% of the samples. The pfmdr1 86Y, 184F and 1246Y mutations were found in 16.2%, 50.0% and 1.6% of the samples, respectively. The pfdhfr 108N, 51I and 59R mutations were identified in 81.9%, 77.4% and 79.4% of the samples, respectively. The double mutant (108N and 51I) was detected in 75.5% of the isolates, and the triple mutant (108N, 51I and 59R) was detected in 73.6% of the isolates. The pfdhps 437G, 436A and 613S mutations were found in 54.4%, 38.6% and 1.2% of the samples, respectively. There was only one double mutant, 437G and 540E, and one quintuple mutant, pfdhfr 108N, 51I and 59R and pfdhps 437G and 540E. The prevalence of the quadruple mutant (pfdhfr 108N, 51I and 59R and pfdhps 437G) was 36.7%. Conclusions The results of this study indicate that an intensive surveillance of the in vitro P. falciparum susceptibility to anti-malarial drugs must be conducted in Senegal.
Collapse
Affiliation(s)
- Bécaye Fall
- Laboratoire d'étude de la chimiosensibilité du paludisme, Fédération des laboratoires, Hôpital Principal de Dakar, Dakar, Sénégal
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Gaillard T, Fall B, Tall A, Wurtz N, Diatta B, Lavina M, Fall KB, Sarr FD, Baret E, Diémé Y, Wade B, Bercion R, Briolant S, Pradines B. Absence of association between ex vivo susceptibility to doxycycline and pftetQ and pfmdt copy numbers in Plasmodium falciparum isolates from Dakar, Senegal. Clin Microbiol Infect 2012; 18:E238-40. [PMID: 22533855 DOI: 10.1111/j.1469-0691.2012.03889.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The objective of this study was to validate the use of pftetQ and pfmdt genes as molecular markers of decreased in vitro susceptibility to doxycycline in 113 Plasmodium falciparum isolates from Dakar, Senegal. The results show that copy numbers of pftetQ and pfmdt, estimated by TaqMan real-time PCR, are not significantly associated with reduced susceptibility to doxycycline in vitro; however, the number of samples with a high doxycycline IC(50) was likely to be too low to derive statistically significant results. Thus, no definitive conclusions could be drawn. The markers should be further tested by analysing more isolates.
Collapse
Affiliation(s)
- T Gaillard
- Unité de Parasitologie - Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes - UMR 6236, Institut de Recherche Biomédicale des Armées, Marseille, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Fall B, Diawara S, Sow K, Baret E, Diatta B, Fall KB, Mbaye PS, Fall F, Diémé Y, Rogier C, Wade B, Bercion R, Pradines B. Ex vivo susceptibility of Plasmodium falciparum isolates from Dakar, Senegal, to seven standard anti-malarial drugs. Malar J 2011; 10:310. [PMID: 22014157 PMCID: PMC3210113 DOI: 10.1186/1475-2875-10-310] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Accepted: 10/20/2011] [Indexed: 11/15/2022] Open
Abstract
Background As a result of widespread chloroquine and sulphadoxine-pyrimethamine resistance, artemisinin-based combination therapy (ACT) (which includes artemether-lumefantrine and artesunate-amodiaquine) has been recommended as a first-line anti-malarial regimen in Senegal since 2006. Since then, there have been very few reports on the ex vivo susceptibility of Plasmodium falciparum to anti-malarial drugs. To examine whether parasite susceptibility has been affected by the widespread use of ACT, the ex vivo susceptibility of local isolates was assessed at the military hospital of Dakar. Methods The ex vivo susceptibility of 93 P. falciparum isolates from Dakar was successfully determined using the Plasmodium lactate dehydrogenase (pLDH) ELISA for the following drugs: chloroquine (CQ), quinine (QN), mefloquine (MQ), monodesethylamodiaquine (MDAQ), lumefantrine (LMF), dihydroartemisinin (DHA) and doxycycline (DOX). Results After transformation of the isolate IC50 in ratio of IC50 according to the susceptibility of the 3D7 reference strain (isolate IC50/3D7 IC50), the prevalence of the in vitro resistant isolates with reduced susceptibility was 50% for MQ, 22% for CQ, 12% for DOX, 6% for both QN and MDAQ and 1% for the drugs LMF and DHA. The highest significant positive correlations were shown between responses to CQ and MDAQ (r = 0.569; P < 0.0001), LMF and QN (r = 0.511; P < 0.0001), LMF and DHA (r = 0.428; P = 0.0001), LMF and MQ (r = 0.413; P = 0.0002), QN and DHA (r = 0.402; P = 0.0003) and QN and MQ (r = 0.421; P = 0.0001). Conclusions The introduction of ACT in 2002 has not induced a decrease in P. falciparum susceptibility to the drugs DHA, MDAQ and LMF, which are common ACT components. However, the prevalence of P. falciparum isolates with reduced susceptibility has increased for both MQ and DOX. Taken together, these data suggest that intensive surveillance of the P. falciparum in vitro susceptibility to anti-malarial drugs in Senegal is required.
Collapse
Affiliation(s)
- Bécaye Fall
- 1Laboratoire d’étude de la chimiosensibilité du paludisme, Fédération deslaboratoires, Hôpital Principal de Dakar, Dakar, Sénégal
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Pradines B, Bertaux L, Pomares C, Delaunay P, Marty P. Reduced in vitro susceptibility to artemisinin derivatives associated with multi-resistance in a traveller returning from South-East Asia. Malar J 2011; 10:268. [PMID: 21923936 PMCID: PMC3185277 DOI: 10.1186/1475-2875-10-268] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 09/18/2011] [Indexed: 11/10/2022] Open
Abstract
Decreased in vitro susceptibility to dihydroartemisinin (21.2 nM) and artesunate (16.3 nM) associated with decreased susceptibility or resistance to quinine (1131 nM), mefloquine (166 nM), lumefantrine (114 nM), pyronaridine (70.5 nM) and piperaquine (91.1 nM) is reported in a patient returning from South-East Asia after trekking along the Mekong from the south of Laos to the north of Thailand. Decreased in vitro susceptibility to artemisinin derivatives did not appear to be mediated by the number of copies of pfmdr1 or pfATPase6, pfcrt, pfmdr1 or pfmrp polymorphism. The high IC50 to mefloquine of this Asian isolate was not associated with pfmdr1 copy number. Pfnhe-1 microsatellite ms4760 showed a profile 7 (ms4760-7) with three repeats of DNNND and one repeat of DDDNHNDNHNN, which is associated with high quinine reduced susceptibility. The patient recovered in three days without relapse after treatment with the association of quinine and doxycycline. Decreased in vitro susceptibility to quinine and the delayed effect of doxycycline may both have contributed to the delayed parasite clearance time, D4 (0.5%) and D7 (0.004%). The in vitro data, with IC50 for dihydroartemisinin and artesunate were up to ten times those of the reference clone W2, which suggests that this isolate may be resistant to artemisinin derivatives, associated with a decreased susceptibility to quinine.
Collapse
Affiliation(s)
- Bruno Pradines
- Unité de Recherche en Biologie et Epidémiologie Parasitaires-Unité de Recherche pour les Maladies Infectieuses et Tropicales Emergentes-UMR 6236, Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France.
| | | | | | | | | |
Collapse
|
18
|
Tan KR, Magill AJ, Parise ME, Arguin PM. Doxycycline for malaria chemoprophylaxis and treatment: report from the CDC expert meeting on malaria chemoprophylaxis. Am J Trop Med Hyg 2011; 84:517-31. [PMID: 21460003 PMCID: PMC3062442 DOI: 10.4269/ajtmh.2011.10-0285] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Doxycycline, a synthetically derived tetracycline, is a partially efficacious causal prophylactic (liver stage of Plasmodium) drug and a slow acting blood schizontocidal agent highly effective for the prevention of malaria. When used in conjunction with a fast acting schizontocidal agent, it is also highly effective for malaria treatment. Doxycycline is especially useful as a prophylaxis in areas with chloroquine and multidrug-resistant Plasmodium falciparum malaria. Although not recommended for pregnant women and children < 8 years of age, severe adverse events are rarely reported for doxycycline. This report examines the evidence behind current recommendations for the use of doxycycline for malaria and summarizes the available literature on its safety and tolerability.
Collapse
Affiliation(s)
- Kathrine R Tan
- Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Atlanta, GA 30341, USA.
| | | | | | | | | |
Collapse
|
19
|
Absence of association between piperaquine in vitro responses and polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe genes in Plasmodium falciparum. Antimicrob Agents Chemother 2010; 54:3537-44. [PMID: 20547801 DOI: 10.1128/aac.00183-10] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We have analyzed the profiles of 23 of Plasmodium falciparum strains for their in vitro chemosusceptibilities to piperaquine (PPQ), dihydroartemisinin (DHA), chloroquine, monodesethylamodiaquine, quinine, mefloquine, lumefantrine, atovaquone, pyrimethamine, and doxycycline (DOX) in association with polymorphisms in genes involved in quinoline resistance (Plasmodium falciparum crt [pfcrt], pfmdr1, pfmrp, and pfnhe). The 50% inhibitory concentrations (IC(50)s) for PPQ ranged from 29 to 98 nM (geometric mean = 57.8 nM, 95% confidence interval [CI] = 51 to 65) and from 0.4 to 5.8 nM for DHA (geometric mean = 1.8 nM, 95% CI = 1.4 to 2.3). We found a significant positive correlation between the responses to PPQ and DHA (r(2) = 0.17; P = 0.0495) and between the responses to PPQ and DOX (r(2) = 0.41; P = 0.001). We did not find a significant association between the PPQ IC(50) (0.0525 < P < 0.9247) or the DHA IC(50) (0.0138 < P < 0.9018) and polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe-1 genes. There was an absence of cross-resistance with quinolines, and the IC(50)s for PPQ and DHA were found to be unrelated to mutations in the pfcrt, pfmdr1, pfmrp, and pfnhe-1 transport protein genes, which are involved in quinoline antimalarial drug resistance. These results confirm the interest in and the efficacy of the combination of PPQ and DHA for areas in which parasites are resistant to chloroquine or other quinolines.
Collapse
|
20
|
Plasmodium falciparum proteome changes in response to doxycycline treatment. Malar J 2010; 9:141. [PMID: 20500856 PMCID: PMC2890676 DOI: 10.1186/1475-2875-9-141] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 05/25/2010] [Indexed: 12/27/2022] Open
Abstract
Background The emergence of Plasmodium falciparum resistance to most anti-malarial compounds has highlighted the urgency to develop new drugs and to clarify the mechanisms of anti-malarial drugs currently used. Among them, doxycycline is used alone for malaria chemoprophylaxis or in combination with quinine or artemisinin derivatives for malaria treatment. The molecular mechanisms of doxycycline action in P. falciparum have not yet been clearly defined, particularly at the protein level. Methods A proteomic approach was used to analyse protein expression changes in the schizont stage of the malarial parasite P. falciparum following doxycycline treatment. A comparison of protein expression between treated and untreated protein samples was performed using two complementary proteomic approaches: two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and isobaric tagging reagents for relative and absolute quantification (iTRAQ). Results After doxycycline treatment, 32 and 40 P. falciparum proteins were found to have significantly deregulated expression levels by 2D-DIGE and iTRAQ methods, respectively. Although some of these proteins have been already described as being deregulated by other drug treatments, numerous changes in protein levels seem to be specific to doxycycline treatment, which could perturb apicoplast metabolism. Quantitative reverse transcription polymerase chain reaction (RT-PCR) was performed to confirm this hypothesis. Conclusions In this study, a specific response to doxycycline treatment was distinguished and seems to involve mitochondrion and apicoplast organelles. These data provide a starting point for the elucidation of drug targets and the discovery of mechanisms of resistance to anti-malarial compounds.
Collapse
|
21
|
Reliability of antimalarial sensitivity tests depends on drug mechanisms of action. J Clin Microbiol 2010; 48:1651-60. [PMID: 20220159 DOI: 10.1128/jcm.02250-09] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In vitro antimalarial activity tests play a pivotal role in malaria drug research or for monitoring drug resistance in field isolates. We applied two isotopic tests, two enzyme-linked immunosorbent assays (ELISA) and the SYBR green I fluorescence-based assay, to test artesunate and chloroquine, the metabolic inhibitors atovaquone and pyrimethamine, our fast-acting choline analog T3/SAR97276, and doxycycline, which has a delayed death profile. Isotopic tests based on hypoxanthine and ethanolamine incorporation are the most reliable tests provided when they are applied after one full 48-h parasite cycle. The SYBR green assay, which measures the DNA content, usually requires 72 h of incubation to obtain reliable results. When delayed death is suspected, specific protocols are required with increasing incubation times up to 96 h. In contrast, both ELISA tests used (pLDH and HRP2) appear to be problematic, leading to disappointing and even erroneous results for molecules that do not share an artesunatelike profile. The reliability of these tests is linked to the mode of action of the drug, and the conditions required to get informative results are hard to predict. Our results suggest some minimal conditions to apply these tests that should give rise to a standard 50% inhibitory concentration, regardless of the mechanism of action of the compounds, and highlight that the most commonly used in vitro antimalarial activity tests do not have the same potential. Some of them might not detect the antimalarial potential of new classes of compounds with innovative modes of action, which subsequently could become promising new antimalarial drugs.
Collapse
|
22
|
In vitro activity of mirincamycin (U24729A) against Plasmodium falciparum isolates from Gabon. Antimicrob Agents Chemother 2009; 54:540-2. [PMID: 19841147 DOI: 10.1128/aac.01090-09] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We assessed the in vitro activity of mirincamycin, a lincosamide antibiotic, against Plasmodium falciparum clinical isolates from Gabon. Growth was determined by HRP2 enzyme-linked immunosorbent assay using an adapted protocol with a prolonged incubation time (6 days) to account for antibiotic-induced delayed death. Mirincamycin's cis and trans isomers are more active (median 50% inhibitory concentrations [IC(50)s], 3.2 nM and 2.6 nM) than the comparator drugs clindamycin (IC(50), 12 nM) and doxycycline (IC(50), 720 nM), and therefore, further clinical development is promising.
Collapse
|