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Songsungthong W, Prasopporn S, Bohan L, Srimanote P, Leartsakulpanich U, Yongkiettrakul S. A novel bicyclic 2,4-diaminopyrimidine inhibitor of Streptococcus suis dihydrofolate reductase. PeerJ 2021; 9:e10743. [PMID: 33604179 PMCID: PMC7866885 DOI: 10.7717/peerj.10743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/18/2020] [Indexed: 12/29/2022] Open
Abstract
Streptococcus suis is a Gram-positive bacterial pathogen of pigs and an emerging zoonotic pathogen. It has become increasingly resistant to multiple classes of antibiotics. New drug candidates and knowledge of their targets are needed to combat antibiotic-resistant S. suis. In this study, the open-source Pathogen Box compound library was screened. Thirty hits that effectively inhibited S. suis growth at 10 µM were identified. Among the most potent hits, MMV675968 (a diaminoquinazoline analog) was shown to target S. suis dihydrofolate reductase (SsDHFR) via (1) growth inhibition of an E. coli surrogate whose growth is dependent on exogenously expressed SsDHFR and (2) inhibition of in vitro SsDHFR activity. Thymidine supplement is able to reverse growth inhibition by MMV675968 in both E. coli surrogate and S. suis, indicating that a thymidine-related pathway is a major target of MMV675968. Comparison of MMV675968 with seven DHFR inhibitors representing different core structures revealed that bicyclic 2,4-diaminopyrimidines with long and flexible side chains are highly effective in inhibiting SsDHFR and S. suis growth. MMV675968 and related compounds thus may serve as starting points for developing antibiotics against drug resistant S. suis.
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Affiliation(s)
- Warangkhana Songsungthong
- Biosensing and Bioprospecting Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
| | - Sunisa Prasopporn
- Biosensing and Bioprospecting Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand.,Current Address: Department of Pharmacology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Louise Bohan
- Biosensing and Bioprospecting Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand.,Current Address: School of Pharmacy and Life Sciences, The Robert Gordon University, Aberdeen, United Kingdom
| | - Potjanee Srimanote
- Faculty of Allied Health Sciences, Thammasat University, Klong Luang, Pathum Thani, Thailand
| | - Ubolsree Leartsakulpanich
- Biosensing and Bioprospecting Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
| | - Suganya Yongkiettrakul
- Biosensing and Bioprospecting Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand
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Farrell LJ, Lo R, Wanford JJ, Jenkins A, Maxwell A, Piddock LJV. Revitalizing the drug pipeline: AntibioticDB, an open access database to aid antibacterial research and development. J Antimicrob Chemother 2018; 73:2284-2297. [DOI: 10.1093/jac/dky208] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- L J Farrell
- Institute of Microbiology & Infection, College of Medical & Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - R Lo
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - J J Wanford
- Institute of Microbiology & Infection, College of Medical & Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - A Jenkins
- British Society for Antimicrobial Chemotherapy, Griffin House, 53 Regent Place, Birmingham B1 3NJ, UK
| | - A Maxwell
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - L J V Piddock
- Institute of Microbiology & Infection, College of Medical & Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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3
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Peters W. The chemotherapy of rodent malaria, VII. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2016. [DOI: 10.1080/00034983.1968.11686588] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Arfeen M, Patel DS, Abbat S, Taxak N, Bharatam PV. Importance of cytochromes in cyclization reactions: Quantum chemical study on a model reaction of proguanil to cycloguanil. J Comput Chem 2014; 35:2047-55. [DOI: 10.1002/jcc.23719] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 08/04/2014] [Accepted: 08/06/2014] [Indexed: 12/23/2022]
Affiliation(s)
- Minhajul Arfeen
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
| | - Dhilon S. Patel
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
| | - Sheenu Abbat
- Department of Pharmacoinformatics; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
| | - Nikhil Taxak
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry; National Institute of Pharmaceutical Education and Research (NIPER); S. A. S. Nagar (Mohali) 160 062 Punjab India
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Peters PJ, Thigpen MC, Parise ME, Newman RD. Safety and toxicity of sulfadoxine/pyrimethamine: implications for malaria prevention in pregnancy using intermittent preventive treatment. Drug Saf 2007; 30:481-501. [PMID: 17536875 DOI: 10.2165/00002018-200730060-00003] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Plasmodium falciparum infection during pregnancy is strongly associated with maternal anaemia and low birth weight, contributing to substantial morbidity and mortality in sub-Saharan Africa. Intermittent preventive treatment in pregnancy with sulfadoxine/pyrimethamine (IPTp-SP) has been one of the most effective approaches to reduce the burden of malaria during pregnancy in Africa. IPTp-SP is based on administering >or=2 treatment doses of sulfadoxine/pyrimethamine to pregnant women at predefined intervals after quickening (around 18-20 weeks). Randomised, controlled trials have demonstrated decreased rates of maternal anaemia and low birth weight with this approach. The WHO currently recommends IPTp-SP in malaria-endemic areas of sub-Saharan Africa. However, implementation has been suboptimal in part because of concerns of potential drug toxicities. This review evaluates the toxicity data of sulfadoxine/pyrimethamine, including severe cutaneous adverse reactions, teratogenicity and alterations in bilirubin metabolism. Weekly sulfadoxine/pyrimethamine prophylaxis is associated with rare but potentially fatal cutaneous reactions. Fortunately, sulfadoxine/pyrimethamine use in IPTp programmes in Africa, with 2-4 treatment doses over 6 months, has been well tolerated in multiple IPTp trials. However, sulfadoxine/pyrimethamine should not be administered concurrently with cotrimoxazole given their redundant mechanisms of action and synergistic worsening of adverse drug reactions. Therefore, HIV-infected pregnant women in malaria endemic areas who are already receiving cotrimoxazole prophylaxis should not also receive IPTp-SP. Although folate antagonist use in the first trimester is associated with neural tube defects, large case-control studies have demonstrated that sulfadoxine/pyrimethamine administered as IPTp (exclusively in the second and third trimesters and after organogenesis) does not result in an increased risk of teratogenesis. Folic acid supplementation is recommended for all pregnant women to reduce the rate of congenital anomalies but high doses of folic acid (5 mg/day) may interfere with the antimalarial efficacy of sulfadoxine/pyrimethamine. However, the recommended standard dose of folic acid supplementation (0.4 mg/day) does not affect antimalarial efficacy and may provide the optimal balance to prevent neural tube defects and maintain the effectiveness of IPTp-SP. No clinical association between sulfadoxine/pyrimethamine use and kernicterus has been reported despite the extensive use of sulfadoxine/pyrimethamine and related compounds to treat maternal malaria and congenital toxoplasmosis in near-term pregnant women and newborns. Although few drugs in pregnancy can be considered completely safe, sulfadoxine/pyrimethamine - when delivered as IPTp - has a favourable safety profile. Improved pharmacovigilance programmes throughout Africa are now needed to confirm its safety as access to IPTp-SP increases. Given the documented benefits of IPTp-SP in malaria endemic areas of Africa, access to this treatment for pregnant women should continue to expand.
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Affiliation(s)
- Philip J Peters
- Division of Infectious Diseases, Emory University School of Medicine, Atlanta, Georgia 30303, USA.
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MCGREGOR IA, WILLIAMS K, GOODWIN LG. PYRIMETHAMINE AND SULPHADIAZINE IN TREATMENT OF MALARIA. BRITISH MEDICAL JOURNAL 1996; 2:728-9. [PMID: 14043735 PMCID: PMC1872857 DOI: 10.1136/bmj.2.5359.728] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Bowden K, Hall AD, Birdsall B, Feeney J, Roberts GC. Interactions between inhibitors of dihydrofolate reductase. Biochem J 1989; 258:335-42. [PMID: 2495789 PMCID: PMC1138366 DOI: 10.1042/bj2580335] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The binding of substrates and inhibitors to dihydrofolate reductase was studied by steady-state kinetics and high-field 1H-n.m.r. spectroscopy. A series of 5-substituted 2,4-diaminopyrimidines were examined and were found to be 'tightly binding' inhibitors of the enzyme (Ki less than 10(-9) M). Studies on the binding of 4-substituted benzenesulphonamides and benzenesulphonic acids also established the existence of a 'sulphonamide-binding site' on the enzyme. Subsequent n.m.r. experiments showed that there are two binding sites for the sulphonamides on the enzyme, one of which overlaps the coenzyme (NADPH) adenine-ring-binding site. An examination of the pH-dependence of the binding of sulphonamides to the enzyme indicated the influence of an ionizable group on the enzyme that was not directly involved in the sulphonamide binding. The change in pKa value from 6.7 to 7.2 observed on sulphonamide binding suggests the involvement of a histidine residue, which could be histidine-28.
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Affiliation(s)
- K Bowden
- Department of Chemistry and Biological Chemistry, University of Essex, U.K
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Martin SK, Oduola AM, Milhous WK. Reversal of chloroquine resistance in Plasmodium falciparum by verapamil. Science 1987; 235:899-901. [PMID: 3544220 DOI: 10.1126/science.3544220] [Citation(s) in RCA: 460] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The parasite Plasmodium falciparum, like neoplastic cells, develops resistance to multiple structurally unrelated drugs. If the mechanisms by which P. falciparum and neoplastic cells become resistant are similar, then it may be possible to reverse the resistance in the two types of cells by the same pharmacological agents. Verapamil, a calcium channel blocker, completely reversed chloroquine resistance in two chloroquine-resistant P. falciparum clones from Southeast Asia and Brazil. Verapamil reversed chloroquine resistance at the same concentration (1 X 10(-6)M) as that at which it reversed resistance in multidrug-resistant cultured neoplastic cells. This same concentration of verapamil had no effect on chloroquine-sensitive parasites. Hence, chloroquine resistance in P. falciparum may fit the criteria for the multidrug-resistant phenotype.
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Sirawaraporn W, Yuthavong Y. Potentiating effect of pyrimethamine and sulfadoxine against dihydrofolate reductase from pyrimethamine-sensitive and pyrimethamine-resistant Plasmodium chabaudi. Antimicrob Agents Chemother 1986; 29:899-905. [PMID: 3729346 PMCID: PMC284175 DOI: 10.1128/aac.29.5.899] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Dihydrofolate reductase was partially purified from a pyrimethamine-sensitive Plasmodium chabaudi clone and a pyrimethamine-resistant clone derived from it and used in a study of the inhibitory effect of pyrimethamine and sulfadoxine, both alone and in combination. Kinetic analysis of the inhibitory effect of sulfadoxine against the enzyme from pyrimethamine-sensitive and -resistant parasites revealed that the drug inhibited the former enzyme competitively, with an inhibition constant (Kis) of 0.7 +/- 0.4 mM, but inhibited the latter enzyme noncompetitively, with Kis and Kii of 8.9 +/- 1.2 and 4.1 +/- 1.2 mM, respectively. Previous studies also showed competitive inhibition by pyrimethamine on the former enzyme and noncompetitive inhibition on the latter enzyme, with some 200-fold-lower affinity. Sulfadoxine and pyrimethamine exhibited a mutually potentiating effect on the enzyme activity, as revealed by the concave isoboles and the fractional inhibitions of less than unity. A potentiating effect was observed for the enzymes from both sources and was not dependent on the degree of the purification of the enzyme. Our results can be explained by assuming simultaneous binding of two inhibitors on the enzyme.
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Milhous WK, Weatherly NF, Bowdre JH, Desjardins RE. In vitro activities of and mechanisms of resistance to antifol antimalarial drugs. Antimicrob Agents Chemother 1985; 27:525-30. [PMID: 3890727 PMCID: PMC180089 DOI: 10.1128/aac.27.4.525] [Citation(s) in RCA: 167] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Certain drugs that interfere with folate metabolism (sulfones, sulfonamides, and inhibitors of dihydrofolate reductase) play an important role in the chemotherapy and prophylaxis of malaria. The activities and mechanisms of action of these drugs are regarded as similar in most respects to their activities against procaryotic microorganisms. Believed incapable of utilizing intact exogenous folates, plasmodia have been regarded as dependent on de novo synthesis of required folate cofactors. The present investigation, conducted in pursuit of a method for testing the in vitro susceptibility of Plasmodium falciparum to antifol antimalarial drugs, produced evidence that earlier assumptions about the folate metabolism of this organism are not correct. Three of four isolates of P. falciparum were successfully maintained in a culture medium depleted of folic acid and p-aminobenzoic acid. The antimalarial activities of sulfonamides and dihydrofolate reductase inhibitors were, furthermore, variably antagonized by the presence of folic acid and p-aminobenzoic acid in the culture medium. Optimum conditions for assessment of antifol antimalarial activity in vitro therefore require precise control of these factors in the culture medium. Our results suggest that resistance to antifol antimalarial drugs involves a complex of factors related to both the de novo synthesis of active folate cofactors and the ability to utilize exogenous intact folates in various forms.
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Schmidt LH, Rossan RN. Activities of respository preparations of cycloguanil pamoate and 4,4'-diacetyldiaminodiphenylsulfone, alone and in combination, against infections with Plasmodium cynomolgi in rhesus monkeys. Antimicrob Agents Chemother 1984; 26:611-42. [PMID: 6393864 PMCID: PMC179984 DOI: 10.1128/aac.26.5.611] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The studies summarized in this report were concerned with the capacities of repository preparations of cycloguanil pamoate (CGT-P) to protect rhesus monkeys against infections with drug-susceptible and pyrimethamine-resistant strains of Plasmodium cynomolgi. Administered intramuscularly as a suspension in an oleaginous vehicle, CGT-P (i) provided long-term protection against single and repetitive challenges of rhesus monkeys with sporozoites of the drug-susceptible B and Ro strains, (ii) effected prompt clearance of parasitemia in established infections, and (iii) delayed relapse. Protection was equated to absence of parasites on thick blood films, negative results when blood was transferred to susceptible recipients, and inability to activate infection by splenectomy. Eventual loss of protection was not related to emergence of parasites resistant to cycloguanil (CGT). Although protection varied from monkey to monkey, its mean duration was related directly to size of CGT-P dose and size of particles in the suspension. Urinary excretion studies indicated that protection persisted as long as the daily output of CGT did not fall below that attained with the parenterally administered hydrochloride salt at a dose equivalent to 0.015 mg of CGT per kg. Studies on infections with the resistant Ro/PM strain showed that the activity of CGT-P was compromised severely by resistance to pyrimethamine. Attempts to minimize this liability by concomitant administration of 4,4'-diacetyldiaminodiphenylsulfone met with limited success. These results suggest that even the best of the repository preparations of CGT-P, with or without 4,4'-diacetyldiaminodiphenylsulfone, would be useful only in areas where Plasmodium falciparum and Plasmodium vivax are fully susceptible to chlorguanide and pyrimethamine.
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12
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Ferone R. Folate metabolism in malaria. Bull World Health Organ 1977; 55:291-8. [PMID: 338184 PMCID: PMC2366725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It is known that malaria parasites are inhibited by sulfonamides and antifolate compounds, require 4-aminobenzoic acid for growth, and respond only partly to intact folic and folinic acids. Biochemical data obtained during the last decade on the synthesis of nucleic acid precursors and on folate enzymes in malaria support the hypothesis that malaria parasites are similar to microorganisms that synthesize folate cofactors de novo. Sulfa drugs inhibit plasmodial dihydropteroate synthase (EC 2.5.1.15). Pyrimethamine and many other antifolate compounds bind to tetrahydrofolate dehydrogenase (EC 1.5.1.3) of the parasite more tightly than to the host enzyme. However, the metabolic consequences of the depletion of folate cofactors as a result of drug inhibition are not yet known. Other areas to be studied are the origin of the pteridine moiety of folates, the addition of glutamate(s) in folate cofactor biosynthesis, the means by which intact, exogenous folates affect malarial growth, and demonstration of the enzymes and reactions involving N(5)-methyl tetrahydrofolate.
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Poe M. Antibacterial synergism: a proposal for chemotherapeutic potentiation between trimethoprim and sulfamethoxazole. Science 1976; 194:533-5. [PMID: 788154 DOI: 10.1126/science.788154] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Sulfamethoxazole and other sulfa drugs are moderately potent inhibitors of Escherichia coli dihydrofolate reductase. They also significantly potentiate the inhibition of this enzyme by trimethoprim. The molecular basis for inhibition potentiation is the simultaneous binding of trimethoprim and sulfa by the enzyme. This potentiation may explain the synergism observed when these drugs are used in antibacterial chemotherapy.
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Laing AB. Combinations of 4-aminobenzoic acid competitors and dihydrofolate dehydrogenase inhibitors in the chemotherapy of malaria. A commentary. Bull World Health Organ 1974; 50:231-4. [PMID: 4613505 PMCID: PMC2481193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Potentiating combinations of 4-aminobenzoic acid (PABA) competitors, such as sulfadoxine, sulfalene, or dapsone, and dihydrofolate dehydrogenase(a) (1.5.1.4) inhibitors, such as pyrimethamine or proguanil, have been subjected to various trials over the last decade. By and large they have proved to be effective agents against drug-resistant strains of malaria parasites, and with the small doses required they have been free of toxic effects. Parasite resistance to such combinations has seldom occurred but may be associated with cross-resistance to other combinations. These combinations should be reserved for the treatment of chloroquine-resistant infections and for use as adjuvants in organized malaria eradication campaigns.
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Smith CC, Genther CS. Cross-resistance and collateral susceptibility to antifolic antimalarial compounds. Antimicrob Agents Chemother 1972; 2:103-8. [PMID: 4208273 PMCID: PMC444275 DOI: 10.1128/aac.2.3.103] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Series of strains of Streptococcus faecium ATCC 8043, Lactobacillus casei ATCC 7469, and Pediococcus cerevisiae ATCC 8081 with increasing resistance to the active antifolate antimalarial drugs chlorguanide triazine (CGT), pyrimethamine (PM), and trimethoprim (TMP) were isolated. These mutant strains, stable for at least 3 to 5 years, were examined for cross-resistance and collateral susceptibility to the above compounds and to methotrexate (MTX). Generally, they exhibited cross-resistance to all four compounds, but resistance of a strain to one compound did not predict accurately its resistance to another drug. Unexpectedly, L. casei resistant to CGT exhibited collateral susceptibility to MTX, TMP, and PM varying from 5- to 20-fold. P. cerevisiae developed resistance to CGT readily but maintained its susceptibility to PM and TMP after prolonged exposure to these compounds. Resistance to these antimalarial antifolates was accompanied by only low-grade cross-resistance to MTX, a representative antileukemic antifolate agent.
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Pyrimidines: Pyrimethamine Type. Med Chem 1972. [DOI: 10.1016/b978-0-12-688950-5.50017-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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18
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Biochemistry, Metabolism, and Cultivation of Malaria Parasites. Med Chem 1972. [DOI: 10.1016/b978-0-12-688950-5.50007-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lantz CH, Van Dyke K. Studies concerning the mechanism of action of antimalarial drugs. II. Inhibition of the incorporation of adenosine-5'-monophosphate- 3 H into nucleic acids of erythrocyte-free malarial parasites. Biochem Pharmacol 1971; 20:1157-66. [PMID: 5118114 DOI: 10.1016/0006-2952(71)90346-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Fasan PO. Trimethoprim plus sulphamethoxazole compared with chloroquine in the treatment and suppression of malaria in African schoolchildren. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1971; 65:117-21. [PMID: 4930371 DOI: 10.1080/00034983.1971.11686737] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Richards WH. The combined action of pyrimidines and sulfonamides or sulfones in the chemotherapy of malaria and other protozoal infections. ADVANCES IN PHARMACOLOGY AND CHEMOTHERAPY 1971; 8:121-47. [PMID: 5002795 DOI: 10.1016/s1054-3589(08)60595-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Contacos PG. Treatment of malaria infection. BULLETIN OF THE NEW YORK ACADEMY OF MEDICINE 1969; 45:1077-85. [PMID: 5259668 PMCID: PMC1750471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Cenedella RJ, Marcus LK, Van Dyke K, Saxe LH. Acetylation in vitro of para-aminobenzoic acid by unparasitized and Plasmodium berghei parasitized rat reticulocytes. Exp Parasitol 1969; 25:142-5. [PMID: 5362577 DOI: 10.1016/0014-4894(69)90060-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Reeve P, Taverne J, Bushby SR. Inhibition by pyrimidine analogues of the synthesis of folic acid by trachoma agents. J Hyg (Lond) 1968; 66:295-306. [PMID: 5304542 PMCID: PMC2130637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Abstract
SUMMARYTrimethoprim, a 2,4-diaminopyrimidine derivative which inhibits the growth of some bacteria by interfering with folic acid synthesis, inhibited the growth of several strains of the trachoma agent. Inhibition was most clearly demonstrated by measuring prolongation of mean death time of groups of chick embryos inoculated with a single lethal dose of agent. Over a certain range, prolongation was proportional to the logarithm of concentration of inhibitor; higher concentrations were toxic for the embryo. On a weight basis, trimethoprim was not as active as sulphafurazole. Inoculation in conjunction with sulphafurazole resulted in slight potentiation of activity. A related pyrimidine derivative, the antimalarial drug pyrimethamine, also significantly inhibited the growth of one strain of trachoma.In cell culture, trimethoprim decreased the number of inclusions formed by a suspension of the trachoma agent and induced morphological changes in the inclusions similar to those caused by sulphafurazole.Inhibition of the growth of the trachoma agent in the chick embryo was reversed by leucovorin calcium. It is concluded that, as with bacteria, the drug acts by blocking the folio acid cycle and that the trachoma agent most probably contains a dihydrofolate reductase.
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Bushby SR, Hitchings GH. Trimethoprim, a sulphonamide potentiator. BRITISH JOURNAL OF PHARMACOLOGY AND CHEMOTHERAPY 1968; 33:72-90. [PMID: 5301731 PMCID: PMC1570262 DOI: 10.1111/j.1476-5381.1968.tb00475.x] [Citation(s) in RCA: 316] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Abstract
A cycloguanil-resistant strain of Plasmodium gallinaceum was produced relatively rapidly by passage through chicks treated with low but effective doses of the drug, the dose being increased as resistance developed.The strain was cross-resistant to proguanil but not to pyrimethamine or chloroquine.A strain highly resistant to proguanil was resistant to cycloguanil but only slightly resistant to pyrimethamine.A strain highly resistant to pyrimethamine was resistant to proguanil and cycloguanil.Passage for 20 months through birds treated with doses of cycloguanil which suppressed infection for relatively long periods failed to change the sensitivity of the strain to this drug or to proguanil. Although the relatively large dose did not eradicate the infection in any of the birds, subinoculations demonstrated that parasites were absent from the blood for a period in some of the birds, though infections finally developed.I am indebted to Parke Davis and Company for the supply of cycloguanil, to Imperial Chemical Industries Ltd. for the proguanil hydrochloride and chloroquine phosphate and to Burroughs Wellcome and Company for the pyrimethamine base.
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Laing AB. The treatment of acute malaria with sulforthomidine and a combination of sulforthomidine and pyrimethamine. Bull World Health Organ 1966; 34:308-11. [PMID: 5296138 PMCID: PMC2475937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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BASU PC, SINGH NN, SINGH N. POTENTIATION OF ACTIVITY OF DIAPHENYLSULFONE AND PYRIMETHAMINE AGAINST PLASMODIUM GALLINACEUM AND PLASMODIUM CYNOMOLGI BASTIANELLII. Bull World Health Organ 1964; 31:699-705. [PMID: 14278006 PMCID: PMC2555130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Abstract
In view of the fact that diaphenylsulfone has been shown to have low schizontocidal activity against Plasmodium gallinaceum and to lead to resistance in strains of P. cynomolgi, investigations were undertaken into the joint action of diaphenylsulfone and pyrimethamine against P. gallinaceum in chicks and P. cynomolgi bastianellii in monkeys. These drugs were assayed separately and in various combinations. It was found that at certain dose levels combination of the two drugs led to potentiation of their plasmocidal activity. On the other hand, this synergistic effect was not noted with combinations containing lower dosages of either drug; with these, a simple additive effect occurred. The authors suggest that the two drugs probably act on the same metabolic pathway but that their points of attack may be different. They note also that there was a difference in the response of P. gallinaceum in chicks and of P. cynomolgi bastianellii in monkeys to the combined use of the two drugs.
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SCHELLENBERG KA, COATNEY GR. The influence of antimalarial drugs on nucleic acid synthesis in Plasmodium gallinaceum and Plasmodium berghei. Biochem Pharmacol 1961; 6:143-52. [PMID: 13747452 DOI: 10.1016/0006-2952(61)90158-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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JOYNER LP, KENDALL SB. The mode of action of a mixture of pyrimethamine and sulphadimidine on Eimeria tenella. BRITISH JOURNAL OF PHARMACOLOGY AND CHEMOTHERAPY 1956; 11:454-7. [PMID: 13383127 PMCID: PMC1510568 DOI: 10.1111/j.1476-5381.1956.tb00016.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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GOODWIN LG. Sulphonamides and folic acid antagonists in malaria and toxoplasmosis. Proc R Soc Med 1956; 49:871-3. [PMID: 13379419 PMCID: PMC1889230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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