1
|
The antimicrobial and immunomodulatory effects of Ionophores for the treatment of human infection. J Inorg Biochem 2021; 227:111661. [PMID: 34896767 DOI: 10.1016/j.jinorgbio.2021.111661] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/27/2021] [Accepted: 11/03/2021] [Indexed: 12/18/2022]
Abstract
Ionophores are a diverse class of synthetic and naturally occurring ion transporter compounds which demonstrate both direct and in-direct antimicrobial properties against a broad panel of bacterial, fungal, viral and parasitic pathogens. In addition, ionophores can regulate the host-immune response during communicable and non-communicable disease states. Although the clinical use of ionophores such as Amphotericin B, Bedaquiline and Ivermectin highlight the utility of ionophores in modern medicine, for many other ionophore compounds issues surrounding toxicity, bioavailability or lack of in vivo efficacy studies have hindered clinical development. The antimicrobial and immunomodulating properties of a range of compounds with characteristics of ionophores remain largely unexplored. As such, ionophores remain a latent therapeutic avenue to address both the global burden of antimicrobial resistance, and the unmet clinical need for new antimicrobial therapies. This review will provide an overview of the broad-spectrum antimicrobial and immunomodulatory properties of ionophores, and their potential uses in clinical medicine for combatting infection.
Collapse
|
2
|
Genomics-driven discovery of the biosynthetic gene cluster of maduramicin and its overproduction in Actinomadura sp. J1-007. ACTA ACUST UNITED AC 2020; 47:275-285. [DOI: 10.1007/s10295-019-02256-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 12/09/2019] [Indexed: 02/07/2023]
Abstract
Abstract
Maduramicin is the most efficient and possesses the largest market share of all anti-coccidiosis polyether antibiotics (ionophore); however, its biosynthetic gene cluster (BGC) has yet to been identified, and the associated strains have not been genetically engineered. Herein, we performed whole-genome sequencing of a maduramicin-producing industrial strain of Actinomadura sp. J1-007 and identified its BGC. Additionally, we analyzed the identified BGCs in silico to predict the biosynthetic pathway of maduramicin. We then developed a conjugation method for the non-spore-forming Actinomadura sp. J1-007, consisting of a site-specific integration method for gene overexpression. The maduramicin titer increased by 30% to 7.16 g/L in shake-flask fermentation following overexpression of type II thioesterase MadTE that is the highest titer at present. Our findings provide insights into the biosynthetic mechanism of polyethers and provide a platform for the metabolic engineering of maduramicin-producing microorganisms for overproduction and development of maduramicin analogs in the future.
Collapse
|
3
|
Antoszczak M, Steverding D, Huczyński A. Anti-parasitic activity of polyether ionophores. Eur J Med Chem 2019; 166:32-47. [DOI: 10.1016/j.ejmech.2019.01.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/08/2019] [Accepted: 01/15/2019] [Indexed: 02/04/2023]
|
4
|
Affiliation(s)
- Barbara Johnson
- Science Applications International Corporation, McLean, Virginia
| |
Collapse
|
5
|
Sonzogni-Desautels K, Renteria AE, Camargo FV, Di Lenardo TZ, Mikhail A, Arrowood MJ, Fortin A, Ndao M. Oleylphosphocholine (OlPC) arrests Cryptosporidium parvum growth in vitro and prevents lethal infection in interferon gamma receptor knock-out mice. Front Microbiol 2015; 6:973. [PMID: 26441906 PMCID: PMC4585137 DOI: 10.3389/fmicb.2015.00973] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 09/01/2015] [Indexed: 12/31/2022] Open
Abstract
Cryptosporidium parvum is a species of protozoa that causes cryptosporidiosis, an intestinal disease affecting many mammals including humans. Typically, in healthy individuals, cryptosporidiosis is a self-limiting disease. However, C. parvum can cause a severe and persistent infection that can be life-threatening for immunocompromised individuals, such as AIDS patients. As there are no available treatments for these patients that can cure the disease, there is an urgent need to identify treatment options. We tested the anti-parasitic activity of the alkylphosphocholine oleylphosphocholine (OlPC), an analog of miltefosine, against C. parvum in in vitro and in vivo studies. In vitro experiments using C. parvum infected human ileocecal adenocarcinoma cells (HCT-8 cells) showed that OlPC has an EC50 of 18.84 nM. Moreover, no cell toxicity has been seen at concentrations ≤50 μM. C57BL/6 interferon gamma receptor knock-out mice, were infected by gavage with 4000 C. parvum oocysts on Day 0. Oral treatments, with OlPC, miltefosine, paromomycin or PBS, began on Day 3 post-infection for 10 days. Treatment with OlPC, at 40 mg/kg/day resulted in 100% survival, complete clearance of parasite in stools and a 99.9% parasite burden reduction in the intestines at Day 30. Doses of 30 and 20 mg/kg/day also demonstrated an increased survival rate and a dose-dependent parasite burden reduction. Mice treated with 10 mg/kg/day of miltefosine resulted in 50% survival at Day 30. In contrast, control mice, treated with PBS or 100 mg/kg/day of paromomycin, died or had to be euthanized between Days 6 and 13 due to severe illness. Results of parasite burden were obtained by qPCR and cross-validated by both flow cytometry of stool oocysts and histological sections of the ileum. Together, our results strongly support that OlPC represents a potential candidate for the treatment of C. parvum infections in immunocompromised patients.
Collapse
Affiliation(s)
- Karine Sonzogni-Desautels
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal QC, Canada ; Institute of Parasitology, Macdonald Campus, McGill University, Montreal QC, Canada
| | - Axel E Renteria
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal QC, Canada ; Department of Experimental Medicine, McGill University, Montreal QC, Canada
| | - Fabio V Camargo
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal QC, Canada
| | | | - Alexandre Mikhail
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal QC, Canada
| | - Michael J Arrowood
- Division of Foodborne, Waterborne, and Environmental Diseases, Center for Disease Control and Prevention, Atlanta GA, USA
| | - Anny Fortin
- Department of Biochemistry, McGill University, Montreal QC, Canada ; Dafra Pharma R&D Turnhout, Belgium
| | - Momar Ndao
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal QC, Canada ; Institute of Parasitology, Macdonald Campus, McGill University, Montreal QC, Canada ; Department of Experimental Medicine, McGill University, Montreal QC, Canada
| |
Collapse
|
6
|
Bedi B, McNair NN, Förster I, Mead JR. IL-18 Cytokine Levels Modulate Innate Immune Responses and Cryptosporidiosis in Mice. J Eukaryot Microbiol 2014; 62:44-50. [DOI: 10.1111/jeu.12164] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 06/09/2014] [Accepted: 07/11/2014] [Indexed: 02/03/2023]
Affiliation(s)
- Brahmchetna Bedi
- Atlanta VA Medical Center; Decatur Georgia USA
- Department of Pediatrics; Emory University; Atlanta Georgia USA
| | - Nina N. McNair
- Department of Pediatrics; Emory University; Atlanta Georgia USA
| | - Irmgard Förster
- Immunology and Environment; Life and Medical Sciences (LIMES) Institute; University of Bonn; Bonn Germany
| | - Jan R. Mead
- Atlanta VA Medical Center; Decatur Georgia USA
- Department of Pediatrics; Emory University; Atlanta Georgia USA
| |
Collapse
|
7
|
Ndao M, Nath-Chowdhury M, Sajid M, Marcus V, Mashiyama ST, Sakanari J, Chow E, Mackey Z, Land KM, Jacobson MP, Kalyanaraman C, McKerrow JH, Arrowood MJ, Caffrey CR. A cysteine protease inhibitor rescues mice from a lethal Cryptosporidium parvum infection. Antimicrob Agents Chemother 2013; 57:6063-73. [PMID: 24060869 PMCID: PMC3837922 DOI: 10.1128/aac.00734-13] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 09/16/2013] [Indexed: 02/06/2023] Open
Abstract
Cryptosporidiosis, caused by the protozoan parasite Cryptosporidium parvum, can stunt infant growth and can be lethal in immunocompromised individuals. The most widely used drugs for treating cryptosporidiosis are nitazoxanide and paromomycin, although both exhibit limited efficacy. To investigate an alternative approach to therapy, we demonstrate that the clan CA cysteine protease inhibitor N-methyl piperazine-Phe-homoPhe-vinylsulfone phenyl (K11777) inhibits C. parvum growth in mammalian cell lines in a concentration-dependent manner. Further, using the C57BL/6 gamma interferon receptor knockout (IFN-γR-KO) mouse model, which is highly susceptible to C. parvum, oral or intraperitoneal treatment with K11777 for 10 days rescued mice from otherwise lethal infections. Histologic examination of untreated mice showed intestinal inflammation, villous blunting, and abundant intracellular parasite stages. In contrast, K11777-treated mice (210 mg/kg of body weight/day) showed only minimal inflammation and no epithelial changes. Three putative protease targets (termed cryptopains 1 to 3, or CpaCATL-1, -2, and -3) were identified in the C. parvum genome, but only two are transcribed in infected mammals. A homology model predicted that K11777 would bind to cryptopain 1. Recombinant enzymatically active cryptopain 1 was successfully targeted by K11777 in a competition assay with a labeled active-site-directed probe. K11777 exhibited no toxicity in vitro and in vivo, and surviving animals remained free of parasites 3 weeks after treatment. The discovery that a cysteine protease inhibitor provides potent anticryptosporidial activity in an animal model of infection encourages the investigation and development of this biocide class as a new, and urgently needed, chemotherapy for cryptosporidiosis.
Collapse
Affiliation(s)
- Momar Ndao
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Center, Montreal, Canada
| | - Milli Nath-Chowdhury
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Center, Montreal, Canada
| | - Mohammed Sajid
- Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California, USA
- Leiden University Medical Center, Leiden, Netherlands
| | - Victoria Marcus
- Department of Pathology, McGill University Health Centre, Montreal General Hospital, Montreal, Canada
| | - Susan T. Mashiyama
- Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California, USA
| | - Judy Sakanari
- Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California, USA
| | - Eric Chow
- Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California, USA
| | - Zachary Mackey
- Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California, USA
| | - Kirkwood M. Land
- Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California, USA
- Department of Biological Sciences, University of the Pacific, Stockton, California, USA
| | - Matthew P. Jacobson
- Departments of Pharmaceutical Sciences
- Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California, USA
| | - Chakrapani Kalyanaraman
- Departments of Pharmaceutical Sciences
- Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California, USA
| | - James H. McKerrow
- Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California, USA
| | - Michael J. Arrowood
- Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California, USA
| |
Collapse
|
8
|
Kevin Ii DA, Meujo DA, Hamann MT. Polyether ionophores: broad-spectrum and promising biologically active molecules for the control of drug-resistant bacteria and parasites. Expert Opin Drug Discov 2009; 4:109-46. [PMID: 23480512 PMCID: PMC4896753 DOI: 10.1517/17460440802661443] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND As multidrug-resistant (MDR) pathogens continue to emerge, there is a substantial amount of pressure to identify new drug candidates. Carboxyl polyethers, also referred to as polyether antibiotics, are a unique class of compounds with outstanding potency against a variety of critical infectious disease targets including protozoa, bacteria and viruses. The characteristics of these molecules that are of key interest are their selectivity and high potency against several MDR etiological agents. OBJECTIVE Although many studies have been published about carboxyl polyether antibiotics, there are no recent reviews of this class of drugs. The purpose of this review is to provide the reader with an overview of the spectrum of activity of polyether antibiotics, their mechanism of action, toxicity and potential as drug candidates to combat drug-resistant infectious diseases. CONCLUSION Polyether ionophores show a high degree of promise for the potential control of drug-resistant bacterial and parasitic infections. Despite the long history of use of this class of drugs, very limited medicinal chemistry and drug optimization studies have been reported, thus leaving the door open to these opportunities in the future. Scifinder and PubMed were the main search engines used to locate articles relevant to the topic presented in the present review. Keywords used in our search were specific names of each of the 88 compounds presented in the review as well as more general terms such as polyethers, ionophores, carboxylic polyethers and polyether antibiotics.
Collapse
Affiliation(s)
- Dion A Kevin Ii
- Professor of Pharmacy, Chemistry & Biochemistry University of Mississippi, National Center for Natural Products Research, CSO of Triton Biopharma, Department of Pharmacognosy, 407 Faser Hall, University, MS 38677, USA +1 662 915 5730 ; +1 662 915 6975 ;
| | | | | |
Collapse
|
9
|
Bobel-24 activity against Cryptosporidium parvum in cell culture and in a SCID mouse model. Antimicrob Agents Chemother 2007; 52:1150-2. [PMID: 18160525 DOI: 10.1128/aac.01019-07] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The anticryptosporidial activity of Bobel-24 (2,4,6-triiodophenol) was studied for the first time, resulting in a reduction of the in vitro growth of Cryptosporidium of up to 99.6%. In a SCID mouse model of chronic cryptosporidiosis, significant differences (P < 0.05) in oocyst shedding were observed in animals treated with 125 mg/kg/day. These results merit further investigation of Bobel-24 as a chemotherapeutic option for cryptosporidiosis.
Collapse
|
10
|
Abstract
Cryptosporidium parvum is a protozoan parasite that infects the epithelial cells of the small intestine causing diarrheal illness in humans. Cryptosporidium has a worldwide distribution and is considered an emerging zoonosis. Despite intensive efforts to develop workable experimental models, and the evaluation of over 200 chemotherapeutic agents, adequate therapies to clear the host of these parasites are still lacking. The reasons for the lack of drug efficacy are probably manifold and may include the unusual location of the parasite in the host cell, distinct structural and biochemical composition, or its ability to either block import or rapidly efflux drug molecules. Understanding some of the basic mechanisms by which drugs are transported to the parasite and identifying unique targets is a first step in developing effective therapeutic agents.
Collapse
Affiliation(s)
- Jan R Mead
- Atlanta Veterans Medical Center and Department of Pediatrics, Emory University, 1670 Clairmont Road, Decatur, GA 30033, USA.
| |
Collapse
|
11
|
Nelson RG, Rosowsky A. Dicyclic and tricyclic diaminopyrimidine derivatives as potent inhibitors of Cryptosporidium parvum dihydrofolate reductase: structure-activity and structure-selectivity correlations. Antimicrob Agents Chemother 2001; 45:3293-303. [PMID: 11709300 PMCID: PMC90829 DOI: 10.1128/aac.45.12.3293-3303.2001] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A structurally diverse library of 93 lipophilic di- and tricyclic diaminopyrimidine derivatives was tested for the ability to inhibit recombinant dihydrofolate reductase (DHFR) cloned from human and bovine isolates of Cryptosporidium parvum (J. R. Vásquez et al., Mol. Biochem. Parasitol. 79:153-165, 1996). In parallel, the library was also tested against human DHFR and, for comparison, the enzyme from Escherichia coli. Fifty percent inhibitory concentrations (IC(50)s) were determined by means of a standard spectrophotometric assay of DHFR activity with dihydrofolate and NADPH as the cosubstrates. Of the compounds tested, 25 had IC(50)s in the 1 to 10 microM range against one or both C. parvum enzymes and thus were not substantially different from trimethoprim (IC(50)s, ca. 4 microM). Another 25 compounds had IC(50)s of <1.0 microM, and 9 of these had IC(50)s of <0.1 microM and thus were at least 40 times more potent than trimethoprim. The remaining 42 compounds were weak inhibitors (IC(50)s, >10 microM) and thus were not considered to be of interest as drugs useful against this organism. A good correlation was generally obtained between the results of the spectrophotometric enzyme inhibition assays and those obtained recently in a yeast complementation assay (V. H. Brophy et al., Antimicrob. Agents Chemother. 44:1019-1028, 2000; H. Lau et al., Antimicrob. Agents Chemother. 45:187-195, 2001). Although many of the compounds in the library were more potent than trimethoprim, none had the degree of selectivity of trimethoprim for C. parvum versus human DHFR. Collectively, the results of these assays comprise the largest available database of lipophilic antifolates as potential anticryptosporidial agents. The compounds in the library were also tested as inhibitors of the proliferation of intracellular C. parvum oocysts in canine kidney epithelial cells cultured in folate-free medium containing thymidine (10 microM) and hypoxanthine (100 microM). After 72 h of drug exposure, the number of parasites inside the cells was quantitated by indirect immunofluorescence microscopy. Sixteen compounds had IC(50)s of <3 microM, and five of these had IC(50)s of <0.3 microM and thus were comparable in potency to trimetrexate. The finding that submicromolar concentrations of several of the compounds in the library could inhibit in vitro growth of C. parvum in host cells in the presence of thymidine (dThd) and hypoxanthine (Hx) suggests that lipophilic DHFR inhibitors, in combination with leucovorin, may find use in the treatment of intractable C. parvum infections.
Collapse
Affiliation(s)
- R G Nelson
- Division of Infectious Diseases, Department of Medicine, University of California, San Francisco, California 94143, USA
| | | |
Collapse
|
12
|
Griffiths JK, Theodos C, Paris M, Tzipori S. The gamma interferon gene knockout mouse: a highly sensitive model for evaluation of therapeutic agents against Cryptosporidium parvum. J Clin Microbiol 1998; 36:2503-8. [PMID: 9705383 PMCID: PMC105153 DOI: 10.1128/jcm.36.9.2503-2508.1998] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptosporidiosis is a serious disease in malnourished children and in people with malignancies or AIDS. Current rodent models for evaluating drug therapy against cryptosporidiosis have many limitations, including the need for a high inoculum, the absence of symptoms resembling those seen in humans, and the need to maintain exogenous immunosuppression. We have developed a gamma interferon knockout (GKO) mouse model with which to evaluate therapies against C. parvum and have used paromomycin for evaluation of this model. The GKO model offers considerable improvements over other systems, since it requires no additional immunosuppression and adult mice can be infected with as few as 10 oocysts (compared with 10(7) for SCID mice). Infected mice develop profound gastrointestinal dysfunction due to extensive infection and severe mucosal damage involving the entire small intestine. Clinical symptoms, which include depression, anorexia, weight loss, and wasting, result in death within 2 to 4 weeks. The time of death depends on the oocyst challenge dose. Paromomycin modulated parasitological and clinical parameters in highly predictable and significant ways, including prevention of death. In addition, examination of the extensively infected gut provided an important insight into the dynamics between a specific drug treatment, its impact on the extent and the site of parasite distribution, and clinical outcome. These uniform symptoms of weight loss, wasting, and death are powerful new parameters which bring this model closer to the actual disease seen in humans and other susceptible mammalian species.
Collapse
Affiliation(s)
- J K Griffiths
- Division of Infectious Disease, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA
| | | | | | | |
Collapse
|
13
|
Woods KM, Nesterenko MV, Upton SJ. Efficacy of 101 antimicrobials and other agents on the development of Cryptosporidium parvum in vitro. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1996; 90:603-15. [PMID: 9039272 DOI: 10.1080/00034983.1996.11813090] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
An in-situ ELISA was used as a primary screen to test the effects of 101 antimicrobials and other agents on the development of Cryptosporidium parvum in vitro. Over 40 of the compounds displayed some form of anticryptosporidial activity, and dose-response curves were generated for 40 of these. The in-situ ELISA makes a highly effective primary, pharmaceutical screen for C parvum, to be used prior to more detailed microscopical, toxicological or in-vivo assays.
Collapse
Affiliation(s)
- K M Woods
- Division of Biology, Kansas State University, Manhattan 66506, USA
| | | | | |
Collapse
|
14
|
You X, Arrowood MJ, Lejkowski M, Xie L, Schinazi RF, Mead JR. A chemiluminescence immunoassay for evaluation of Cryptosporidium parvum growth in vitro. FEMS Microbiol Lett 1996; 136:251-6. [PMID: 8867380 DOI: 10.1111/j.1574-6968.1996.tb08057.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A chemiluminescence immunoassay (CLIA) was developed to detect Cryptosporidium parvum growth in Madin-Darby canine kidney (MDCK) cell cultures. Optimal results were obtained when MDCK cells were plated at a density of 1 x 10(4) cells/well (96-well plate) and maintained as a monolayer for 4 days prior to infection with 2 x 10(4) parasites/well. Two compounds (paromomycin and maduramicin) were evaluated and shown to have selective activity against C. parvum in a dose-dependent manner. There was excellent correlation between CLIA and immunofluorescence assay when assessing anti-C. parvum agents in MDCK cells. CLIA offers advantages over conventional enzyme-linked immunosorbent assay and immunofluorescence assay methods in that it is more sensitive and efficient. The combination of CLIA and MDCK culture provides an efficient tool for evaluating potential anti-cryptosporidial compounds prior to testing in animal models.
Collapse
Affiliation(s)
- X You
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | | | | | | | |
Collapse
|
15
|
Arrowood MJ, Mead JR, Xie L, You X. In vitro anticryptosporidial activity of dinitroaniline herbicides. FEMS Microbiol Lett 1996; 136:245-9. [PMID: 8867379 DOI: 10.1111/j.1574-6968.1996.tb08056.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Despite the evaluation of over 100 antimicrobial drugs, the diarrheal disease cryptosporidiosis has remained refractory to treatment. We report the evaluation of five dinitroaniline herbicides including trifluralin, profluralin, nitralin, pendimethalin, and fluchloralin for anticryptosporidial activity in an in vitro cultivation model of Cryptosporidium parvum. All five compounds exhibited significant anticryptosporidial activities with no corresponding evidence of toxicity. The most active compound was pendimethalin with an IC50 of 0.19 microM while nitralin was the least active with an IC50 of 4.5 microM. These compounds should be evaluated further in an animal model of cryptosporidiosis.
Collapse
Affiliation(s)
- M J Arrowood
- National Center for Infectious Diseases, Centers for Disease Control and Prevention, Public Health Service, U.S. Department of Health and Human Services, Atlanta, GA 30341-3724, USA. mja0/ciddpd2.em.cdc.gov
| | | | | | | |
Collapse
|