ABSTRACT
The global prevalence of fungal infections is alarming in both the pre- and post- COVID period. Due to a limited number of antifungal drugs, there are hurdles in treatment strategies for fungal infections due to toxic potential, drug interactions, and the development of fungal resistance. All the antifungal targets (existing and newer) and pipeline molecules showing promise against these targets are reviewed. The objective was to predict or repurpose phyto-based antifungal compounds based on a dual target inhibition approach (Sterol-14-α- demethylase and HSP-90) using a case study. In pursuit of repurposing the phytochemicals as antifungal agents, a team of researchers visited Aravalli Biodiversity Park (ABP), Delhi, India, to collect information on available medicinal plants. From 45 plants, a total of 1149 ligands were collected, and virtual screening was performed using Schrodinger Suite 2016 software to get 83 hits against both the target proteins: Sterol-14-α-demethylase and HSP-90. After analysis of docking results, ligands were selected based on their interaction against both the target proteins and comparison with respective standard ligands (fluconazole and ganetespib). We have selected Isocarthamidin, Quercetin and Boeravinone B based on their docking score and binding interaction against the HSP-90 (Docking Score -9.65, -9.22 and -9.21, respectively) and 14-α-demethylase (Docking Score -9.19, -10.76 and -9.74 respectively). The docking protocol was validated and MM/GBSA studies depicted better stability of selected three ligands (Isocarthamidin, Quercetin, Boeravinone B) complex as compared to standard complex. Further, MD simulation studies were performed using the Desmond (67) software package version 2018-4. All the findings are presented as a case study for the prediction of dual targets for the repurposing of certain phytochemicals as antifungal agents.
Subject(s)
Antifungal Agents , Drug Repositioning , Molecular Docking Simulation , Phytochemicals , Antifungal Agents/pharmacology , Antifungal Agents/chemistry , India , Humans , Phytochemicals/pharmacology , Phytochemicals/chemistry , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Sterol 14-Demethylase/metabolism , Sterol 14-Demethylase/chemistry , Plants, Medicinal/chemistry , Quercetin/pharmacology , Quercetin/chemistry , Plant Extracts/pharmacology , Plant Extracts/chemistry , Mycoses/drug therapy , Mycoses/microbiologyABSTRACT
Background: Diagnosis of co-infections with multiple pathogens among hospitalized coronavirus disease 2019 (COVID-19) patients can be jointly challenging and essential for appropriate treatment, shortening hospital stays and preventing antimicrobial resistance. This study proposes to investigate the burden of bacterial and fungal co-infections outcomes on COVID-19 patients. It is a single center cross-sectional study of hospitalized COVID-19 patients at Beit-Jala hospital in Palestine. Methods: The study included 321 hospitalized patients admitted to the ICU between June 2020 and March 2021 aged ≥20 years, with a confirmed diagnosis of COVID-19 via reverse transcriptase-polymerase chain reaction assay conducted on a nasopharyngeal swab. The patient's information was gathered using graded data forms from electronic medical reports. Results: The diagnosis of bacterial and fungal infection was proved through the patient's clinical presentation and positive blood or sputum culture results. All cases had received empirical antimicrobial therapy before the intensive care unit (ICU) admission, and different regimens during the ICU stay. The rate of bacterial co-infection was 51.1%, mainly from gram-negative isolates ( Enterobacter species and K.pneumoniae). The rate of fungal co-infection caused by A.fumigatus was 48.9%, and the mortality rate was 8.1%. However, it is unclear if it had been attributed to SARS-CoV-2 or coincidental. Conclusions: Bacterial and fungal co-infection is common among COVID-19 patients at the ICU in Palestine, but it is not obvious if these cases are attributed to SARS-CoV-2 or coincidental, because little data is available to compare it with the rates of secondary infection in local ICU departments before the pandemic. Comprehensively, those conclusions present data supporting a conservative antibiotic administration for severely unwell COVID-19 infected patients. Our examination regarding the impacts of employing antifungals to manage COVID-19 patients can work as a successful reference for future COVID-19 therapy.
Subject(s)
Bacterial Infections , COVID-19 , Coinfection , Mycoses , Arabs , Bacterial Infections/drug therapy , Bacterial Infections/epidemiology , COVID-19/epidemiology , Coinfection/epidemiology , Cross-Sectional Studies , Hospitals , Humans , Intensive Care Units , Mycoses/drug therapy , Mycoses/epidemiology , Mycoses/microbiology , Retrospective Studies , SARS-CoV-2ABSTRACT
Fungal diseases have become a major public health issue worldwide. Increasing drug resistance and the limited number of available antifungals result in high morbidity and mortality. Metal-based drugs have been reported to be therapeutic agents against major protozoan diseases, but knowledge of their ability to function as antifungals is limited. In this study, we found that calcium supplementation combined with iron deficiency causes dramatic growth inhibition of the human fungal pathogens Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. Calcium induces the downregulation of iron uptake-related genes and, in particular, causes a decrease in the expression of the transcription factor HapX, which tends to transcriptionally activate siderophore-mediated iron acquisition under iron-deficient conditions. Iron deficiency causes calcium overload and the overproduction of intracellular reactive oxygen species (ROS), and perturbed ion homeostasis suppresses fungal growth. These phenomena are consistently identified in azole-resistant A. fumigatus isolates. The findings here imply that low iron availability lets cells mistakenly absorb calcium as a substitute, causing calcium abnormalities. Thus, there is a mutual effect between iron and calcium in fungal pathogens, and the combination of calcium with an iron chelator could serve to improve antifungal therapy. IMPORTANCE Millions of immunocompromised people are at a higher risk of developing different types of severe fungal diseases. The limited number of antifungals and the emergence of antimicrobial resistance highlight an urgent need for new strategies against invasive fungal infections. Here, we report that calcium can interfere with iron absorption of fungal pathogens, especially in iron-limited environments. Thus, a combination of calcium supplementation with an iron chelator inhibits the growth of human fungal pathogens, including Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. Moreover, we demonstrate that iron deficiency induces a nonspecific calcium uptake response, which results in toxic levels of metal. Findings in this study suggest that a microenvironment with excess calcium and limited iron is an efficient strategy to curb the growth of fungal pathogens, especially for drug-resistant isolates.
Subject(s)
Cryptococcosis , Cryptococcus neoformans , Iron Deficiencies , Mycoses , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Aspergillus fumigatus , Calcium/metabolism , Calcium/pharmacology , Calcium/therapeutic use , Candida albicans/metabolism , Cryptococcus neoformans/metabolism , Dietary Supplements , Drug Resistance, Fungal , Humans , Iron/metabolism , Mycoses/microbiology , Siderophores/metabolism , Siderophores/pharmacology , Siderophores/therapeutic useABSTRACT
Fungal infections are one of the main public health problems, especially in immunocompromised patients, nosocomial environments, patients with chronic diseases, and transplant recipients. These diseases are increasingly frequent and lethal because the microorganism has a high capacity to acquire resistance to available therapy. The main resistance factors are the emergence of new strains and the uncontrolled use of antifungals. It is, therefore, important to develop new methods that contribute to combating fungal diseases in the clinical area. Natural products have considerable potential for the development of new drugs with antifungal activity, mainly due to their biocompatibility and low toxic effect. This promising antimicrobial activity of natural products is mainly due to the presence of flavonoids, terpenes, and quinones, which explains their antifungal potential. Pharmaceutical nanotechnology has been explored to enhance the delivery, selectivity, and clinical efficacy of these products. Nanotechnological systems provide a safe and selective environment for various substances, such as natural products, improving antifungal activity. However, further safety experiments (in vivo or clinical trials) need to be carried out to prove the therapeutic action of natural products, since they may have undesirable, toxic, and mutagenic effects. Therefore, this review article addresses the main nanotechnological methods using natural products for effective future treatment against the main fungal diseases.
Subject(s)
Biological Products , Mycoses , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Biological Products/pharmacology , Biological Products/therapeutic use , Humans , Mycoses/drug therapy , Mycoses/microbiology , Nanomedicine , Terpenes/therapeutic useABSTRACT
Despite abundant research in the field of antifungal drug discovery, fungal infections remain a significant healthcare burden. There is an emerging need for the development of novel antifungals since those currently available are limited and do not completely provide safe and secure protection. Since the current knowledge regarding the physiology of fungal cells and the infection mechanisms is greater than ever, we have the opportunity to use this for the development of novel generations of antifungals. In this review, we selected and summarized recent studies describing agents employing different antifungal mechanisms. These mechanisms include interference with fungal resistance, including impact on the efflux pumps and heat shock protein 90. Additionally, interference with virulence factors, such as biofilms and hyphae; the impact on fungal enzymes, metabolism, mitochondria, and cell wall; and antifungal vaccines are explored. The agents investigated belong to different classes of natural or synthetic molecules with significant attention given also to plant extracts. The efficacy of these antifungals has been studied mainly in vitro with some in vivo, and clinical studies are needed. Nevertheless, there is a large quantity of products employing novel antifungal mechanisms that can be further explored for the development of new generation of antifungals.
Subject(s)
Antifungal Agents , Mycoses , Antifungal Agents/metabolism , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Biofilms , Cell Wall/metabolism , Drug Resistance, Fungal , Humans , Hyphae , Mycoses/microbiologyABSTRACT
The limited number of available effective agents necessitates the development of new antifungals. We report that jervine, a jerveratrum-type steroidal alkaloid isolated from Veratrum californicum, has antifungal activity. Phenotypic comparisons of cell wall mutants, K1 killer toxin susceptibility testing, and quantification of cell wall components revealed that ß-1,6-glucan biosynthesis was significantly inhibited by jervine. Temperature-sensitive mutants defective in essential genes involved in ß-1,6-glucan biosynthesis, including BIG1, KEG1, KRE5, KRE9, and ROT1, were hypersensitive to jervine. In contrast, point mutations in KRE6 or its paralog SKN1 produced jervine resistance, suggesting that jervine targets Kre6 and Skn1. Jervine exhibited broad-spectrum antifungal activity and was effective against human-pathogenic fungi, including Candida parapsilosis and Candida krusei. It was also effective against phytopathogenic fungi, including Botrytis cinerea and Puccinia recondita. Jervine exerted a synergistic effect with fluconazole. Therefore, jervine, a jerveratrum-type steroidal alkaloid used in pharmaceutical products, represents a new class of antifungals active against mycoses and plant-pathogenic fungi. IMPORTANCE Non-Candida albicans Candida species (NCAC) are on the rise as a cause of mycosis. Many antifungal drugs are less effective against NCAC, limiting the available therapeutic agents. Here, we report that jervine, a jerveratrum-type steroidal alkaloid, is effective against NCAC and phytopathogenic fungi. Jervine acts on Kre6 and Skn1, which are involved in ß-1,6-glucan biosynthesis. The skeleton of jerveratrum-type steroidal alkaloids has been well studied, and more recently, their anticancer properties have been investigated. Therefore, jerveratrum-type alkaloids could potentially be applied as treatments for fungal infections and cancer.
Subject(s)
Alkaloids/pharmacology , Antifungal Agents/pharmacology , Cell Wall/metabolism , Fungi/drug effects , Plant Extracts/pharmacology , Veratrum/chemistry , beta-Glucans/metabolism , Alkaloids/isolation & purification , Antifungal Agents/isolation & purification , Candida/drug effects , Candida/genetics , Candida/metabolism , Cell Wall/drug effects , Fungi/genetics , Fungi/metabolism , Humans , Mycoses/microbiology , Plant Extracts/isolation & purificationABSTRACT
Bauhinia scandens L. (Family: Fabaceae) is commonly used to treat cholera, diarrhea, asthma, and diabetes disorder in integrative medicine. This study aimed to screen the presence of phytochemicals (preliminary and UPLC-QTOF-M.S. analysis) and to examine the pharmacological activities of Bauhinia scandens L. stems (MEBS) stem extracts. Besides, in silico study was also implemented to elucidate the binding affinity and drug capability of the selected phytochemicals. In vivo anti diarrheal activity was investigated in mice models. In vitro, antibacterial and antifungal properties of MEBS against several pathogenic strains were evaluated using the disc diffusion method. In addition, in silico study has been employed using Discovery studio 2020, UCFS Chimera, PyRx autodock vina, and online tools. In the anti-diarrheal investigation, MEBS showed a significant dose-dependent inhibition rate in all three methods. The antibacterial and antifungal screening showed a remarkable zone of inhibition, of the diameter 14-26 mm and 12-28 mm, by MEBS. The present study revealed that MEBS has remarkable anti-diarrheal potential and is highly effective in wide-spectrum bacterial and fungal strains. Moreover, the in silico study validated the results of biological screenings. To conclude, MEBS is presumed to be a good source in treating diarrhea, bacterial and fungal infections.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antidiarrheals/pharmacology , Antifungal Agents/pharmacology , Bauhinia/chemistry , Diarrhea , Phytochemicals/pharmacology , Plant Extracts/pharmacology , Animals , Bacteria/drug effects , Bacterial Infections/drug therapy , Bacterial Infections/microbiology , Diarrhea/chemically induced , Diarrhea/drug therapy , Diarrhea/microbiology , Disease Models, Animal , Fungi/drug effects , Mice , Mycoses/drug therapy , Mycoses/microbiology , Phytotherapy , Plant Extracts/chemistry , Plant Stems/chemistryABSTRACT
The past year has established the link between the COVID-19 pandemic and the global spread of severe fungal infections; thus, underscoring the critical need for rapid and realizable fungal disease diagnostics. While in recent years, health authorities, such as the Centers for Disease Control and Prevention, have reported the alarming emergence and spread of drug-resistant pathogenic fungi and warned against the devastating consequences, progress in the diagnosis and treatment of fungal infections is limited. Early diagnosis and patient-tailored therapy are established to be key in reducing morbidity and mortality associated with fungal (and cofungal) infections. As such, antifungal susceptibility testing (AFST) is crucial in revealing susceptibility or resistance of these pathogens and initiating correct antifungal therapy. Today, gold standard AFST methods require several days for completion, and thus this much delayed time for answer limits their clinical application. This review focuses on the advancements made in developing novel AFST techniques and discusses their implications in the context of the practiced clinical workflow. The aim of this work is to highlight the advantages and drawbacks of currently available methods and identify the main gaps hindering their progress toward clinical application.
Subject(s)
Antifungal Agents/therapeutic use , COVID-19/epidemiology , Mycoses/diagnosis , Mycoses/drug therapy , COVID-19/virology , Diagnostic Tests, Routine , Drug Resistance, Fungal , Humans , Microbial Sensitivity Tests , Mycoses/epidemiology , Mycoses/microbiology , Pandemics , SARS-CoV-2/isolation & purificationABSTRACT
A worldwide increase in the incidence of fungal infections, emergence of new fungal strains, and antifungal resistance to commercially available antibiotics indicate the need to investigate new treatment options for fungal diseases. Therefore, the interest in exploring the antifungal activity of medicinal plants has now been increased to discover phyto-therapeutics in replacement to conventional antifungal drugs. The study was conducted to explore and identify the mechanism of action of antifungal agents of edible plants, including Cinnamomum zeylanicum, Cinnamomum tamala, Amomum subulatum, Trigonella foenumgraecum, Mentha piperita, Coriandrum sativum, Lactuca sativa, and Brassica oleraceae var. italica. The antifungal potential was assessed via the disc diffusion method and, subsequently, the extracts were assessed for phytochemicals and total antioxidant activity. Potent polyphenols were detected using high-performance liquid chromatography (HPLC) and antifungal mechanism of action was evaluated in silico. Cinnamomum zeylanicum exhibited antifungal activity against all the tested strains while all plant extracts showed antifungal activity against Fusarium solani. Rutin, kaempferol, and quercetin were identified as common polyphenols. In silico studies showed that rutin displayed the greatest affinity with binding pocket of fungal 14-alpha demethylase and nucleoside diphosphokinase with the binding affinity (Kd, -9.4 and -8.9, respectively), as compared to terbinafine. Results indicated that Cinnamomum zeylanicum and Cinnamomum tamala exert their antifungal effect possibly due to kaempferol and rutin, respectively, or possibly by inhibition of nucleoside diphosphokinase (NDK) and 14-alpha demethylase (CYP51), while Amomum subulatum and Trigonella foenum graecum might exhibit antifungal potential due to quercetin. Overall, the study demonstrates that plant-derived products have a high potential to control fungal infections.
Subject(s)
Antifungal Agents/chemistry , Biological Products/chemistry , Mycoses/drug therapy , Polyphenols/chemistry , Amomum/chemistry , Antifungal Agents/pharmacology , Antioxidants/chemistry , Biological Products/isolation & purification , Biological Products/pharmacology , Brassica/chemistry , Cinnamomum zeylanicum/chemistry , Coriandrum/chemistry , Lactuca/chemistry , Mentha piperita/chemistry , Mycoses/microbiology , Phytochemicals/chemistry , Phytochemicals/pharmacology , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plants, Edible/chemistry , Plants, Medicinal/chemistry , Polyphenols/isolation & purification , Polyphenols/pharmacology , Quercetin/chemistry , Quercetin/isolation & purification , Quercetin/pharmacology , Trigonella/chemistryABSTRACT
Epilobium angustifolium L. is a popular medicinal plant found in many regions of the world. This plant contains small amounts of essential oil whose composition and properties have not been extensively investigated. There are few reports in the literature on the antioxidant and antifungal properties of this essential oil and the possibility of applying it as a potential promoter of the skin penetration of drugs. The essential oil was obtained by distillation using a Clavenger type apparatus. The chemical composition was analyzed by the GC-MS method. The major active compounds of E. angustifolium L. essential oil (EOEa) were terpenes, including α-caryophyllene oxide, eucalyptol, ß-linalool, camphor, (S)-carvone, and ß-caryophyllene. The analyzed essential oil was also characterized by antioxidant activity amounting to 78% RSA (Radical Scavenging Activity). Antifungal activity against the strains Aspergillus niger, A. ochraceus, A. parasiticum, and Penicillium cyclopium was also determined. The largest inhibition zone was observed for strains from the Aspergillus group. The EOEa enhanced the percutaneous penetration of ibuprofen and lidocaine. After a 24 h test, the content of terpene in the skin and the acceptor fluid was examined. It has been shown that the main compounds contained in the essential oil do not penetrate through the skin, but accumulate in it. Additionally, FTIR-ATR analysis showed a disturbance of the stratum corneum (SC) lipids caused by the essential oil application. Due to its rich composition and high biological activity, EOEa may be a potential candidate to be applied, for example, in the pharmaceutical or cosmetic industries. Moreover, due to the reaction of the essential oil components with SC lipids, the EOEa could be an effective permeation enhancer of topically applied hydrophilic and lipophilic drugs.
Subject(s)
Epilobium/chemistry , Mycoses/drug therapy , Oils, Volatile/chemistry , Plant Extracts/chemistry , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Aspergillus/drug effects , Aspergillus/pathogenicity , Gas Chromatography-Mass Spectrometry , Humans , Mycoses/microbiology , Oils, Volatile/pharmacology , Penicillium/drug effects , Penicillium/pathogenicity , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Skin/drug effects , Skin Absorption/drug effects , Terpenes/chemistry , Terpenes/pharmacologyABSTRACT
(1) Background: Candida is the most common cause of fungal infections worldwide, but due to the limited option of antifungal therapies, alternative strategies are required. (2) Methods: Adenophora triphylla var. japonica extract was used for the biofilm formation assay using RPMI1640. The combinatorial antifungal assay, the dimorphic transition assay, and the adherence assay were done to see the influence of inhibition of biofilm formation. qRT-PCR analysis were performed to check the gene expression. (3) Results: Adenophora triphylla var. japonica extract inhibited the Candida biofilm formation. Treatment of extract increased the antifungal susceptibility of miconazole from a 37% reduction in fungal growth to 99.05%, and also dose-dependently reduced the dimorphic transition of Candida and the attachment of Candida to HaCaT cells. The extract blocked the expression of hyphal-related genes, extracellular matrix genes, Ras1-cAMP-PKA pathway genes, Cph2-Tec1 pathway gene, and MAP kinase pathway gene. (4) Conclusions: In this study, the treatment of Adenophora triphylla var. japonica extract showed inhibition of fungal biofilm formation, activation of antifungal susceptibility, and reduction of infection. These results suggest that fungal biofilm formation is a good target for the development of antifungal adjuvants, and Adenophora triphylla var. japonica extract should be a good candidate for biofilm-associated fungal infections.
Subject(s)
Campanulaceae/chemistry , Candida albicans/drug effects , Mycoses/drug therapy , Plant Extracts/pharmacology , Antifungal Agents/pharmacology , Biofilms/drug effects , Candida albicans/pathogenicity , Cell Aggregation/drug effects , Humans , Hyphae/drug effects , Mycoses/microbiology , Plant Extracts/chemistryABSTRACT
Due to the increased morbidity and mortality by fungal infections and the emergence of severe antifungal resistance, there is an urgent need for new antifungal agents. Here, we screened for antifungal activity in our in-house library through the minimum inhibitory concentration test and derived two hit compounds with moderate antifungal activities. The hit compounds' antifungal activities and drug-like properties were optimized by substituting various aryl ring, alkyl chain, and methyl groups. Among the optimized compounds, 22h was the most promising candidate with good drug-like properties and exhibited potent fast-acting fungicidal antifungal effects against various fungal pathogens and synergistic antifungal activities with some known antifungal drugs. Additionally, 22h was further confirmed to disturb fungal cell wall integrity by activating multiple cell wall integrity pathways. Furthermore, 22h exerted significant antifungal efficacy in both the subcutaneous infection mouse model and ex vivo human nail infection model.
Subject(s)
Antifungal Agents/therapeutic use , Fungi/drug effects , Mycoses/drug therapy , Animals , Antifungal Agents/pharmacokinetics , Antifungal Agents/pharmacology , Antifungal Agents/toxicity , Cell Wall/drug effects , Drug Evaluation, Preclinical , Drug Synergism , Female , Humans , Male , Mice , Microbial Sensitivity Tests , Mycoses/microbiology , Rats, Sprague-DawleyABSTRACT
PURPOSE: To report the clinical and confocal findings of a unique case of combined Phialemonium curvatum and Acanthamoeba keratitis and to highlight the role of the prompt diagnosis and specific medical treatment in preserving visual function. METHODS: A case report and literature review. RESULTS: A 54-year-old woman presented with a 3-day history of visual impairment, photophobia, and ocular pain in her right eye. Her best corrected visual acuity was 0.4 Logarithm of the Minimum Angle of Resolution scale, and the slit-lamp examination showed whitish corneal stromal infiltrate with satellite lesions. In vivo confocal microscopy evidenced Acanthamoeba cysts and fungal hyphae that resulted P. curvatum in the culture examination. The intensive medical treatment was started with topical 0.02% polyhexamethylene biguanide, voriconazole 1%, and moxifloxacin hydrochloride 0.5%. Progressive improvement of clinical and confocal pictures was registered with a complete recovery of visual function after 1 month. CONCLUSIONS: This is the first case report of combined P. curvatum and Acanthamoeba keratitis. The fast diagnosis with in vivo confocal microscopy allowed early and intensive specific treatment with recovery of corneal infection.
Subject(s)
Acanthamoeba Keratitis/diagnosis , Ascomycota/isolation & purification , Eye Infections, Fungal/diagnosis , Keratitis/diagnosis , Mycoses/diagnosis , Acanthamoeba Keratitis/drug therapy , Acanthamoeba Keratitis/parasitology , Administration, Ophthalmic , Anti-Bacterial Agents/therapeutic use , Antifungal Agents/therapeutic use , Biguanides/therapeutic use , Disinfectants/therapeutic use , Drug Therapy, Combination , Early Diagnosis , Eye Infections, Fungal/drug therapy , Eye Infections, Fungal/microbiology , Female , Humans , Keratitis/drug therapy , Keratitis/microbiology , Microscopy, Confocal , Middle Aged , Moxifloxacin/therapeutic use , Mycoses/drug therapy , Mycoses/microbiology , Ophthalmic Solutions , Slit Lamp Microscopy , Voriconazole/therapeutic useABSTRACT
BACKGROUND: Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the main killers of people all over the world. The major hurdles with existing therapy are the lengthy regimen and appearance of multi drug resistant (MDR) and extensively drug resistant (XDR) strains of M.tuberculosis. AIMS: The present work was aimed to synthesize and determine antitubercular and antimicrobial potential of some novel 3-chloro-4-aryl-1-[4-(5-pyrazin-2-yl[1,3,4]oxadiazole-2-ylmethoxy)-phenyl]-azetidin-2-one derivatives 7: (A: -H: ) from pyrazinoic acid as precursor, which is a well-established antitubercular agent. Here we report the synthesis of a new class of heterocyclic molecules in which pyrazine, 1, 3, 4-oxadiazole and azetidinone moieties were present in one frame work. METHODS: Pyrazinoic acid (1: ) was esterified first (2: ) followed by amination to produce hydrazide (3: ) which was refluxed with POCl3 to obtain 2-chloromethyl-5pyrazino-1, 3, 4-oxadiazole (4: ). This was then further reacted with 4-amino phenol to obtain 4-[5-pyrazino-1, 3, 4-oxadiazol-2-yl-methoxy]-phenyl amine (5: ) which on condensation with various aromatic aldehydes afforded a series Schiff's bases 6(A-H): . Dehydrative annulations of 6(A-H): in the presence of chloroacetyl chloride and triethylamine yielded 3-chloro-4-aryl-1-[4-(5-pyrazin-2-yl-[1, 3, 4]oxadiazole-2-ylmethoxy)-phenyl]-azetidin-2-one derivatives 7(A-H): . Antibacterial, antifungal and antitubercular potential of all the synthesized compounds were assessed. Docking study was performed using the software VLife Engine tools of Vlifemds 4.6 on the protein lumazine synthase of M. tuberculosis (PDB entry code 2C92). RESULTS: The present studies demonstrated that synthesized oxadiazole derivatives have good antimicrobial activity against the various microorganisms. Among the synthesized derivative, 7B: and 7G: were found to be prominent compounds which have potential antibacterial, antifungal and antitubercular activity (with MIC 3.12 µg/ml and high dock score ranging from -59.0 to -54.0) against Mycobacterium tuberculosis. CONCLUSIONS: Derivatives 7B: and 7G: would be effective lead candidates for tuberculosis therapy.
Subject(s)
Antifungal Agents/pharmacology , Antitubercular Agents/pharmacology , Pyrazinamide/analogs & derivatives , Antifungal Agents/therapeutic use , Antitubercular Agents/chemistry , Antitubercular Agents/therapeutic use , Aspergillus niger/drug effects , Azetidines/chemistry , Azetidines/pharmacology , Azetidines/therapeutic use , Candida albicans/drug effects , Drug Evaluation, Preclinical , Humans , Microbial Sensitivity Tests , Molecular Docking Simulation , Mycobacterium tuberculosis/drug effects , Mycoses/drug therapy , Mycoses/microbiology , Oxadiazoles/chemistry , Oxadiazoles/pharmacology , Oxadiazoles/therapeutic use , Pyrazinamide/chemistry , Pyrazinamide/pharmacology , Pyrazinamide/therapeutic use , Tuberculosis/drug therapy , Tuberculosis/microbiologyABSTRACT
BACKGROUND: Infectious keratitis is the main cause of preventable blindness worldwide, with about 1.5-2.0 million new cases occurring per year. This inflammatory response may be due to infections caused by bacteria, fungi, viruses or parasites. Fungal keratitis is a poorly studied health problem. OBJECTIVES: This study aimed to identify a new fungal species by molecular methods and to explore the possible efficacy of the three most common antifungals used in human keratitis in Mexico by performing in vitro analysis. The capacity of this pathogen to cause corneal infection in a murine model was also evaluated. METHODS: The fungal strain was isolated from a patient with a corneal ulcer. To identify the fungus, taxonomic and phylogenetic analyses (nrDNA ITS and LSU data set) were performed. An antifungal susceptibility assay for amphotericin B, itraconazole and voriconazole was carried out. The fungal isolate was used to develop a keratitis model in BALB/c mice; entire eyes and ocular tissues were preserved and processed for histopathologic examination. RESULTS AND CONCLUSION: This fungal genus has hitherto not been reported with human keratitis in Mexico. We described a new species Purpurecillium roseum isolated from corneal infection. P roseum showed resistance to amphotericin B and itraconazole and was sensitive to voriconazole. In vivo study demonstrated that P roseum had capacity to developed corneal infection and to penetrate deeper corneal tissue. The global change in fungal infections has emphasised the need to develop better diagnostic mycology laboratories and to recognise the group of potential fungal pathogens.
Subject(s)
Antifungal Agents/therapeutic use , Hypocreales/classification , Hypocreales/drug effects , Hypocreales/isolation & purification , Keratitis/microbiology , Aged , Amphotericin B/therapeutic use , Animals , Cornea , DNA, Fungal , Drug Resistance, Fungal/drug effects , Female , Humans , Hypocreales/pathogenicity , Itraconazole/therapeutic use , Keratitis/drug therapy , Keratitis/pathology , Mexico , Mice , Mice, Inbred BALB C , Microbial Sensitivity Tests , Mycological Typing Techniques , Mycoses/drug therapy , Mycoses/microbiology , Phylogeny , Voriconazole/therapeutic useABSTRACT
The essential oils (EOs) of Origanum floribundum Munby, an aromatic and medicinal plant endemic in Algeria, were extracted by different hydrodistillation times (30 min, 1, 2 and 3 h) and analyzed by GC and GC-MS. The chromatographic analysis showed that thymol (32.7-45.0%), p-cymene (16.8-23.1%) and γ-terpinene (21.6-28.7%) were the most prominent components of the oils. The antioxidant ability was measured using the reductive potential, thiobarbituric acid reactive substances (TBARS) assay and the inhibition of free radicals DPPHâ and ABTSâ+. Antibacterial activity was assessed by the disc diffusion method against three bacteria (Escherichia coli, Staphylococcus aureus and Bacillus subtilis) and one fungus (Candida albicans). Minimal inhibitory concentrations (MICs) were determined using a microdilution method. Thymol is one of the compounds of EOs, which are widely reported as very biologically active. Although the oil isolated for 30 min was the less-thymol rich, it was the most active with all the antioxidant tests. In the most cases, the antimicrobial activity showed the best results with oils isolated for 30 min and 3 h (MIC = 0.25-1.75 µL/mL). These results suggest that it might be possible to isolate the EO from this plant for a minimum distillation time to obtain oil that can give maximum biological activities.
Subject(s)
Bacterial Infections/drug therapy , Mycoses/drug therapy , Oils, Volatile/chemistry , Origanum/chemistry , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Bacillus subtilis/drug effects , Bacillus subtilis/pathogenicity , Bacterial Infections/microbiology , Candida albicans/drug effects , Candida albicans/pathogenicity , Cyclohexane Monoterpenes/chemistry , Cyclohexane Monoterpenes/isolation & purification , Cymenes/chemistry , Cymenes/isolation & purification , Distillation , Escherichia coli/drug effects , Escherichia coli/pathogenicity , Gas Chromatography-Mass Spectrometry , Humans , Mycoses/microbiology , Plant Extracts/chemistry , Plant Extracts/pharmacology , Staphylococcus aureus/drug effects , Staphylococcus aureus/pathogenicity , Thymol/chemistry , Thymol/isolation & purificationABSTRACT
Invasive fungal infections in humans are generally associated with high mortality, making the choice of antifungal drug crucial for the outcome of the patient. The limited spectrum of antifungals available and the development of drug resistance represent the main concerns for the current antifungal treatments, requiring alternative strategies. Antimicrobial peptides (AMPs), expressed in several organisms and used as first-line defenses against microbial infections, have emerged as potential candidates for developing new antifungal therapies, characterized by negligible host toxicity and low resistance rates. Most of the current literature focuses on peptides with antibacterial activity, but there are fewer studies of their antifungal properties. This review focuses on AMPs with antifungal effects, including their in vitro and in vivo activities, with the biological repercussions on the fungal cells, when known. The classification of the peptides is based on their mode of action: although the majority of AMPs exert their activity through the interaction with membranes, other mechanisms have been identified, including cell wall inhibition and nucleic acid binding. In addition, antifungal compounds with unknown modes of action are also described. The elucidation of such mechanisms can be useful to identify novel drug targets and, possibly, to serve as the templates for the synthesis of new antimicrobial compounds with increased activity and reduced host toxicity.
Subject(s)
Antimicrobial Cationic Peptides/pharmacology , Fungi/drug effects , Pore Forming Cytotoxic Proteins/pharmacology , Animals , Antifungal Agents/chemistry , Antifungal Agents/therapeutic use , Antimicrobial Cationic Peptides/biosynthesis , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/therapeutic use , Biosynthetic Pathways , Drug Resistance, Fungal , Humans , Microbial Sensitivity Tests , Mycoses/drug therapy , Mycoses/microbiology , Pore Forming Cytotoxic Proteins/biosynthesis , Pore Forming Cytotoxic Proteins/chemistry , Pore Forming Cytotoxic Proteins/therapeutic use , Structure-Activity RelationshipABSTRACT
An increasing number of people is affected by fungal biofilm-based infections, which are resistant to the majority of currently-used antifungal drugs. Such infections are often caused by species from the genera Candida, Aspergillus or Cryptococcus. Only a few antifungal drugs, including echinocandins and liposomal formulations of amphotericin B, are available to treat such biofilm-based fungal infections. This review discusses combination therapy as a novel antibiofilm strategy. More specifically, in vitro methods to discover new antibiofilm combinations will be discussed. Furthermore, an overview of the main modes of action of promising antibiofilm combination treatments will be provided as this knowledge may facilitate the optimization of existing antibiofilm combinations or the development of new ones with a similar mode of action.
Subject(s)
Antifungal Agents/therapeutic use , Biofilms/drug effects , Drug Resistance, Fungal/drug effects , Mycoses/drug therapy , Candida/drug effects , Candida/pathogenicity , Humans , Microbial Sensitivity Tests , Mycoses/genetics , Mycoses/microbiologyABSTRACT
A 6-y-old, 3.5-kg, spayed female Toy Poodle was presented with left forelimb lameness of 2-d duration. Two months before the initial presentation, radiography showed osteolysis of the medial epicondyle of the left humerus, and the left forelimb was amputated. Grossly, the articular villi of the elbow joint were markedly thickened, and the articular cartilage surfaces of the distal humerus and proximal radius had partial erosion. Histologically, granulomatous arthritis and osteomyelitis characterized by the presence of abundant macrophages containing numerous fungi were observed. ITS and ß-tubulin sequences amplified from the isolate from the specimen were 100% and 99% identical to type strain UTHSC D16-145T of Talaromyces georgiensis, respectively. Canine osteoarthritis caused by T. georgiensis has not been reported previously, to our knowledge.