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1.
J Contemp Dent Pract ; 21(7): 760-764, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33020359

RESUMO

AIM: One of the most vital characteristics of an ideal root filling material is the capability to inhibit the growth of the microorganisms. Mineral trioxide aggregate (MTA) is one of the most used root repair materials, with approved antibacterial effect. A newly introduced root repair material is nano-fast cement (NFC) which should be investigated. The antibacterial and antifungal activities of NFC were evaluated in the present study. MATERIALS AND METHODS: Enterococcus faecalis (PTCC 1394), Escherichia coli (ATTC 15224), and Candida albicans (PTCC 5027) were employed for the antimicrobial assessment. The following were the steps used to conduct the agar diffusion test (ADT): six agar plates were used. 0.5 McFarland concentration of each strain was cultured on two plates by a sterile cotton-tipped swab. Three holes with 5mm diameter were created on each plate. Freshly mixed cement was placed in the holes of the related plate. After two hours, the plates were incubated at 37°C for 24 hours. Then, the diameter of the growth inhibition zones were measured, and the mean values were used for the analysis. Direct contact test (DCT) was done by using the following steps: Freshly mixed materials were placed in the 96-well microtiter plate. 10 µL of each bacterial suspension was added to the tested cement. After one-hour incubation at 37°C, 245 µL of BHI broth was added to each well, and the plate was vortexed for 2 minutes. About 15 µL of this bacterial suspension was added to a new well which contained 215 µL of fresh medium. The kinetics of the bacterial outgrowth were measured by the microplate spectrophotometer hourly for 12 hours. RESULTS: No significant differences were observed between the diameters of the growth inhibition zones of MTA and NFC groups in ADT. In DCT, the MTA inhibits E. coli more effectively than NFC (p value < 0.001). Both cements had the same inhibitory effect on E. faecalis and C. albicans. CONCLUSION: The MTA and NFC are almost equally effective against the tested microorganisms. CLINICAL SIGNIFICANCE: The antibacterial characteristic of any dental material is an important matter. As well, the antibacterial efficacy of the NFC should be evaluated.


Assuntos
Antifúngicos/farmacologia , Escherichia coli , Compostos de Alumínio , Antibacterianos/farmacologia , Compostos de Cálcio , Combinação de Medicamentos , Óxidos , Materiais Restauradores do Canal Radicular , Silicatos
2.
Folia Biol (Praha) ; 66(3): 91-103, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33069188

RESUMO

The most recent genome-editing system called CRISPR-Cas9 (clustered regularly interspaced short palindromic repeat system with associated protein 9-nuclease) was employed to delete four non-essential genes (i.e., Caeco1, Caidh1, Carom2, and Cataf10) individually to establish their gene functionality annotations in pathogen Candida albicans. The biological roles of these genes were investigated with respect to the cell wall integrity and biogenesis, calcium/calcineurin pathways, susceptibility of mutants towards temperature, drugs and salts. All the mutants showed increased vulnerability compared to the wild-type background strain towards the cell wall-perturbing agents, (antifungal) drugs and salts. All the mutants also exhibited repressed and defective hyphal growth and smaller colony size than control CA14. The cell cycle of all the mutants decreased enormously except for those with Carom2 deletion. The budding index and budding size also increased for all mutants with altered bud shape. The disposition of the mutants towards cell wall-perturbing enzymes disclosed lower survival and more rapid cell wall lysis events than in wild types. The pathogenicity and virulence of the mutants was checked by adhesion assay, and strains lacking rom2 and eco1 were found to possess the least adhesion capacity, which is synonymous to their decreased pathogenicity and virulence.


Assuntos
Candida albicans/fisiologia , Proteínas Fúngicas/fisiologia , Genes Fúngicos , Acetiltransferases/deficiência , Acetiltransferases/genética , Acetiltransferases/fisiologia , Antifúngicos/farmacologia , Sistemas CRISPR-Cas , Cálcio/fisiologia , Candida albicans/efeitos dos fármacos , Candida albicans/genética , Candida albicans/patogenicidade , Cátions/farmacologia , Adesão Celular , Ciclo Celular , Parede Celular/efeitos dos fármacos , Quitinases/farmacologia , Dano ao DNA , Proteínas Fúngicas/genética , Deleção de Genes , Glucana Endo-1,3-beta-D-Glucosidase/farmacologia , Hifas/crescimento & desenvolvimento , Isocitrato Desidrogenase/deficiência , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/fisiologia , Fases de Leitura Aberta , Reprodução Assexuada , Fatores Associados à Proteína de Ligação a TATA/deficiência , Fatores Associados à Proteína de Ligação a TATA/genética , Fatores Associados à Proteína de Ligação a TATA/fisiologia , Virulência/genética
3.
Pestic Biochem Physiol ; 170: 104696, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980050

RESUMO

Combined application of plant essential oils (EOs) with known antimicrobial effects and silica nanocapsules with high loading capacity and protection capability of the EOs make them proper candidates for creating environmentally friendly fungicides. In this study, EOs of the Lemongrass (LGO) and Clove (CO) were used against Gaeumannomyces graminis var. tritici (Ggt), a causal agent of take-all disease of wheat. To provide controlled delivery of the EOs, they were encapsulated into mesoporous silica nanoparticles (MSNPs) and then compared to the effects of pure EOs both in- vitro and in- vivo. MSNPs were synthesized via the sol-gel process. Various techniques such as Fourier transform infrared spectroscopy (FTIR), the Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA), and UV-Vis spectroscopy were used to evaluate the successful loading of the EOs into the pore of MSNPs. The encapsulation efficiency (EE) was calculated as high as 84.24% for LGO and 80.69% for CO, while loading efficiency (LE) was determined 36% and 29% for LGO and CO, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) displayed spherical shapes and porous structures with average diameters of 50-70 nm. Recognition of the main components of the EOs via gas chromatographic-mass spectrometry (GC-MS) before and after the EO loading, detected eugenol and citral as the most frequent compounds in LGO and CO, respectively. For antifungal test in- vitro, selected concentrations of the pure EOs, EOs loaded in MSNPs (EOs- MSNPs) and Mancozeb ® fungicide based on pre-tests were mixed using potato dextrose agar (PDA). The inhibition percentage (IP) of fungal growth at each concentration, as well as minimum inhibition concentration (MIC) and minimum fungicidal concentrations (MFC) were obtained. The results indicated that antifungal effects in the encapsulated form increased by up to three times. In- vivo, the sterile wheat seeds were treated with pure EOs, EOs-MSNPs, and mancozeb at MFC concentration. Also, in order to keep on the EOs-MSNPs around the seeds, sodium alginate was used. The consequences of in- vivo experiments indicated that rate of disease control in presence of EOs-MSNPs and mancozeb was the same (~70%) and higher than pure EOs (LGO: 57.44%, CO: 49%). Also, improving the growth parameters in wheat plant, the covering of the EOs-MSNPs in alginate, had better control (84%) than that of EOs-MSNPs alone. Further, the release kinetics studies showed a gradual release of LGO and CO from MSNPs for four weeks in water and for five weeks in the soil-plant system. To the best of our knowledge, this is the first report of the control effect of LGO, CO, and their nanocapsule in MSNPs against the take-all disease of wheat. These results showed that the EOs-MSNPs can be a safe product for the efficient control of take-all disease in wheat crop.


Assuntos
Cymbopogon , Nanopartículas , Óleos Voláteis/farmacologia , Antifúngicos/farmacologia , Óleo de Cravo/farmacologia , Dióxido de Silício , Triticum
4.
Pestic Biochem Physiol ; 170: 104698, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980053

RESUMO

Essential oils and their main compounds, monoterpenoids, are considered as alternative control systems for phytopathogenic fungi, particularly those related to late diseases of fruits and vegetables, like anthracnose caused by Colletotrichum species. In this context, we studied the effect of twenty monoterpenoids on Colletotrichum fructicola and C. acutatum to elucidate their effectiveness and mechanisms of action. Thus, we analyzed mycelial growth and conidial inhibitory concentration, as well as the effect of selected monoterpenoids on membrane integrity and cell vitality, reactive oxygen species (ROS) accumulation, and mitochondrial membrane potential by flow cytometry. The results showed that oxygenated monoterpenoids (alcohols and aldehydes) exhibited higher antifungal activity than their corresponding hydrocarbons, esters, and cyclic counterparts. Indicating that OH- and O- radicals react with cellular components affecting fungal homeostasis. In this sense, selected monoterpenoids (citral, citronellol, geraniol, carvacrol, and thymol) inhibited conidial germination of C. acutatum in a dose-dependent manner. The inhibition of conidial germination is associated with a loss of membrane integrity, a decrease of cell metabolism, and a dose-dependent accumulation of ROS, which was non-directly associated with modifications on mitochondrial membrane potential. Membrane dysfunction and ROS accumulation may be responsible for the necrotic behavior induced by high monoterpenoids concentrations, and possible apoptotic response in sub dosages of these compounds.


Assuntos
Colletotrichum , Antifúngicos/farmacologia , Frutas , Monoterpenos/farmacologia , Esporos Fúngicos
5.
Pestic Biochem Physiol ; 170: 104705, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980068

RESUMO

Magnolia officinalis, as a well-known herb worldwide, has been widely used to treat multiple diseases for a long time. In this study, the petroleum ether extract from M. officinalis showed effective antifungal activity against seven plant pathogens (particularly against R. solani with an inhibition rate of 100.00% at 250 µg/mL). Honokiol and magnolol, isolated by the bioassay-guided method, exhibited greater antifungal activity than tebuconazole (EC50 = 3.07 µg/mL, p ≤ 0.001) against R. solani, which EC50 values were 2.18 µg/mL and 3.48 µg/mL, respectively. We used transcriptomics to explore the mechanism of action of honokiol against R. solani. Results indicated that honokiol may exert antifungal effects by blocking the oxidative phosphorylation metabolic pathway. Further studies indicated that honokiol induced ROS overproduction, disrupted the mitochondrial function, affected respiration, and blocked the TCA cycle, which eventually inhibited ATP production. Besides, honokiol also damaged cell membranes and caused morphological changes. This study demonstrated that the lignans isolated from M. officinalis possess the potential to be developed as botanical fungicides.


Assuntos
Lignanas/farmacologia , Magnolia , Antifúngicos/farmacologia , Bioensaio , Compostos de Bifenilo
6.
PLoS Genet ; 16(8): e1009005, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32841236

RESUMO

Azole drugs are the most frequently used antifungal agents. The pathogenic yeast Candida glabrata acquires resistance to azole drugs via single amino acid substitution mutations eliciting a gain-of-function (GOF) hyperactive phenotype in the Pdr1 transcription factor. These GOF mutants constitutively drive high transcription of target genes such as the ATP-binding cassette transporter-encoding CDR1 locus. Previous characterization of Pdr1 has demonstrated that this factor is negatively controlled by the action of a central regulatory domain (CRD) of ~700 amino acids, in which GOF mutations are often found. Our earlier experiments demonstrated that a Pdr1 derivative in which the CRD was deleted gave rise to a transcriptional regulator that could not be maintained as the sole copy of PDR1 in the cell owing to its toxically high activity. Using a set of GOF PDR1 alleles from azole-resistant clinical isolates, we have analyzed the mechanisms acting to repress Pdr1 transcriptional activity. Our data support the view that Pdr1-dependent transactivation is mediated by a complex network of transcriptional coactivators interacting with the extreme C-terminal part of Pdr1. These coactivators include but are not limited to the Mediator component Med15A. Activity of this C-terminal domain is controlled by the CRD and requires multiple regions across the C-terminus for normal function. We also provide genetic evidence for an element within the transactivation domain that mediates the interaction of Pdr1 with coactivators on one hand while restricting Pdr1 activity on the other hand. These data indicate that GOF mutations in PDR1 block nonidentical negative inputs that would otherwise restrain Pdr1 transcriptional activation. The strong C-terminal transactivation domain of Pdr1 uses multiple different protein regions to recruit coactivators.


Assuntos
Candida glabrata/efeitos dos fármacos , Candidíase/tratamento farmacológico , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Antifúngicos/efeitos adversos , Antifúngicos/farmacologia , Azóis/efeitos adversos , Azóis/farmacologia , Candida glabrata/genética , Candida glabrata/patogenicidade , Candidíase/genética , Candidíase/microbiologia , Proteínas de Ligação a DNA , Farmacorresistência Fúngica/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Humanos , Ativação Transcricional/efeitos dos fármacos
7.
PLoS Negl Trop Dis ; 14(8): e0008493, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32845884

RESUMO

The emergence and spread of cryptococcosis caused by the Cryptococcus gattii species complex has become a major public concern worldwide. C. deuterogattii (VGIIa) outbreaks in the Pacific Northwest region demonstrate the expansion of this fungal infection to temperate climate regions. However, infections due to the C. gattii species complex in China have rarely been reported. In this study, we studied eleven clinical strains of the C. gattii species complex isolated from Guangxi, southern China. The genetic identity and variability of these isolates were analyzed via multi-locus sequence typing (MLST), and the phylogenetic relationships among these isolates and global isolates were evaluated. The mating type, physiological features and antifungal susceptibilities of these isolates were also characterized. Among the eleven isolates, six belonged to C. deuterogattii, while five belonged to C. gattii sensu stricto. The C. deuterogattii strains from Guangxi, southern China were genetically variable and clustered with different clinical isolates from Brazil. All strains were MATα, and three C. deuterogattii isolates (GX0104, GX0105 and GX0147) were able to undergo sexual reproduction. Moreover, most strains had capsule and were capable of melanin production when compared to the outbreak strain from Canada. Most isolates were susceptible to antifungal drugs; yet one of eleven immunocompetent patients died of cryptococcal meningitis caused by C. deuterogattii (GX0147). Our study indicated that the highly pathogenic C. deuterogattii may be emerging in southern China, and effective nationwide surveillance of C. gattii species complex infection is necessary.


Assuntos
Criptococose/epidemiologia , Criptococose/parasitologia , Cryptococcus gattii/genética , Adulto , Antifúngicos/farmacologia , China , Cryptococcus gattii/efeitos dos fármacos , Farmacorresistência Fúngica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia
8.
Nat Commun ; 11(1): 3387, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32636417

RESUMO

Biosynthesis of glycosylphosphatidylinositol (GPI) is required for anchoring proteins to the plasma membrane, and is essential for the integrity of the fungal cell wall. Here, we use a reporter gene-based screen in Saccharomyces cerevisiae for the discovery of antifungal inhibitors of GPI-anchoring of proteins, and identify the oligocyclopropyl-containing natural product jawsamycin (FR-900848) as a potent hit. The compound targets the catalytic subunit Spt14 (also referred to as Gpi3) of the fungal UDP-glycosyltransferase, the first step in GPI biosynthesis, with good selectivity over the human functional homolog PIG-A. Jawsamycin displays antifungal activity in vitro against several pathogenic fungi including Mucorales, and in vivo in a mouse model of invasive pulmonary mucormycosis due to Rhyzopus delemar infection. Our results provide a starting point for the development of Spt14 inhibitors for treatment of invasive fungal infections.


Assuntos
Antifúngicos/farmacologia , Glicosiltransferases/antagonistas & inibidores , Policetídeos/farmacologia , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Animais , Proliferação de Células , Modelos Animais de Doenças , Fermentação , Genes Reporter , Glicosilfosfatidilinositóis/biossíntese , Células HCT116 , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Células K562 , Pulmão/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Mucorales , Família Multigênica , Rhizopus , Saccharomyces cerevisiae
9.
PLoS Genet ; 16(7): e1008611, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32658892

RESUMO

Epimutations in fungal pathogens are emerging as novel phenomena that could explain the fast-developing resistance to antifungal drugs and other stresses. These epimutations are generated by RNA interference (RNAi) mechanisms that transiently silence specific genes to overcome stressful stimuli. The early-diverging fungus Mucor circinelloides exercises a fine control over two interacting RNAi pathways to produce epimutants: the canonical RNAi pathway and a new RNAi degradative pathway. The latter is considered a non-canonical RNAi pathway (NCRIP) because it relies on RNA-dependent RNA polymerases (RdRPs) and a novel ribonuclease III-like named R3B2 to degrade target transcripts. Here in this work, we uncovered the role of NCRIP in regulating virulence processes and transposon movements through key components of the pathway, RdRP1 and R3B2. Mutants in these genes are unable to launch a proper virulence response to macrophage phagocytosis, resulting in a decreased virulence potential. The transcriptomic profile of rdrp1Δ and r3b2Δ mutants revealed a pre-exposure adaptation to the stressful phagosomal environment even when the strains are not confronted by macrophages. These results suggest that NCRIP represses key targets during regular growth and releases its control when a stressful environment challenges the fungus. NCRIP interacts with the RNAi canonical core to protect genome stability by controlling the expression of centromeric retrotransposable elements. In the absence of NCRIP, these retrotransposons are robustly repressed by the canonical RNAi machinery; thus, supporting the antagonistic role of NCRIP in containing the epimutational pathway. Both interacting RNAi pathways might be essential to govern host-pathogen interactions through transient adaptations, contributing to the unique traits of the emerging infection mucormycosis.


Assuntos
Mucorales/genética , Mucormicose/genética , Interferência de RNA , Ribonuclease III/genética , Antifúngicos/farmacologia , Farmacorresistência Fúngica/genética , Epigênese Genética/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica/genética , Instabilidade Genômica/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Mucorales/patogenicidade , Mucormicose/microbiologia , Mutação/genética , RNA Mensageiro/genética , Transdução de Sinais/efeitos dos fármacos , Virulência/genética
10.
J Mycol Med ; 30(3): 101009, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32620497

RESUMO

Chronic renal disease patients under chronic dialysis (CRDD) have a multifactorial immunological deterioration with an increased risk of Candida infections. Incidence of Candida infections is increasing. Choice of suitable antifungal agents is limited due to the resistance of some species to several antifungals. Aim of the present study was to identify the distribution and antifungal susceptibility patterns of oral isolated Candida species from infected and colonized patients, as well as to investigate the risk factors for oral infection in patients on dialysis. Cross-sectional study, approved by the institutional bioethics committees was performed in CRDD patients. Demographic, clinic data, and oral mucosa samples were obtained. Infection diagnosis was established clinically and confirmed with exfoliative cytology, each sample was plated on CHROMagar Candida and incubated at 36°C for 2 days. Yeast species were identified by carbohydrate assimilation ID 32C AUX system and the apiweb database. For the antifungal susceptibility test, the M44 A-3 method (CLSI) using fluconazole (FCZ), miconazole (MCZ), nystatin (NYS), and voriconazole (VCZ). Study included 119 participants, the main cause of CRD was nephropathy due to DM2 (58%), and three-fourths of the patients were under hemodialysis. Candida prevalence was 56.3% of 67 colonized or infected patients, 88 isolates were obtained. Principal identified species were C. albicans (51.1%), C. glabrata (25%), and C. tropicalis (14.8%). C. glabrata showed a reduced response to FCZ in 50% of isolates and C. albicans had a reduced response in 16% of the isolates. Antifungal agent with the least efficacious response or with the lowest susceptibility in the isolates of these patients was MCZ, followed by VCZ and FCZ, whereas NYS induced the best antifungal response.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candidíase Bucal/microbiologia , Boca/microbiologia , Insuficiência Renal Crônica/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Candida/classificação , Candidíase Bucal/complicações , Candidíase Bucal/diagnóstico , Candidíase Bucal/epidemiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/microbiologia , Diabetes Mellitus Tipo 2/terapia , Nefropatias Diabéticas/epidemiologia , Nefropatias Diabéticas/microbiologia , Nefropatias Diabéticas/terapia , Farmacorresistência Fúngica/efeitos dos fármacos , Feminino , Humanos , Masculino , México/epidemiologia , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Diálise Renal/efeitos adversos , Diálise Renal/estatística & dados numéricos , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/terapia , Adulto Jovem
11.
J Mycol Med ; 30(3): 101011, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32693980

RESUMO

INTRODUCTION: Otomycosis, a superficial fungal infection of the external auditory canal (EAC), is a disease with exceptionally high prevalence. AIM: The aim of this study was to determine the prevalence of otomycosis, the distribution of causative species and to evaluate epidemiological characteristics of these infections. METHODOLOGY: The patients' data were collected from record book and database of mycological examinations conducted at Public Health Institute Nis, Serbia. In the period from 2014 to 2018 samples of 1287 patients with symptoms and signs of EAC infection were investigated. Standard mycological methods were used for isolation and determination of fungi. RESULTS: High prevalence of otomycosis was determined in examined patients (22.7%). However, the prevalence rates did not differ significantly in the studied period (p=0.931). The majority of patients were diagnosed with only unilateral EAC infection (82.9%). Considering all patients with otomycosis, mold infections caused by the genus Aspergillus (143/48.9%) were more frequent than Candida spp. ear infections (133/45.6%), with Aspergillus niger and Candida аlbicans being predominant causative agents. Mixed Aspergillus and Candida otomycosis was established in 16 (5.5%) patients. Otomycosis was more common in male subjects (26.8%, p=0.003) who also suffered from Aspergillus otomycosis more frequently (17.5%, p<0.001). The prevalence of these infections increases with age (p=0.005), while they do not show seasonal pattern (p>0.05). CONCLUSION: Noted high prevalence of otomycosis, with both yeasts and non-dermatophyte molds acting as infectious agents which require different treatment, implies the necessity for further epidemiological monitoring of this form of superficial mycoses.


Assuntos
Otomicose/epidemiologia , Otomicose/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antifúngicos/classificação , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergilose/epidemiologia , Aspergilose/microbiologia , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/isolamento & purificação , Candida/classificação , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candida albicans/efeitos dos fármacos , Candida albicans/isolamento & purificação , Candidíase/tratamento farmacológico , Candidíase/epidemiologia , Candidíase/microbiologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Técnicas de Tipagem Micológica , Otomicose/tratamento farmacológico , Prevalência , Sérvia/epidemiologia , Adulto Jovem
12.
Curr Opin Infect Dis ; 33(4): 290-297, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32657965

RESUMO

PURPOSE OF REVIEW: Although clinical outcomes in the treatment of aspergillosis have markedly improved with the availability of newer triazoles, the development of resistance to these antifungals, especially in Aspergillus fumigatus, is a growing concern. The purpose of this review is to provide an update on azole resistance mechanisms and their epidemiology in A. fumigatus, the clinical implications of azole resistance, and to discuss future treatment options against azole-resistant aspergillosis. RECENT FINDINGS: Resistance may develop through either patient or environmental azole exposure. Environmental exposure is the most prevalent means of resistance development, and these isolates can cause disease in various at-risk groups, which now include those with influenza, and potentially COVID-19. Although current treatment options are limited, newer therapies are in clinical development. These include agents with novel mechanisms of action which have in vitro and in vivo activity against azole-resistant A. fumigatus. SUMMARY: Azole-resistant A. fumigatus is an emerging threat that hampers our ability to successfully treat patients with aspergillosis. Certain geographic regions and patient populations appear to be at increased risk for this pathogen. As new patient groups are increasingly recognized to be at increased risk for invasive aspergillosis, studies to define the epidemiology and management of azole-resistant A. fumigatus are critically needed. While treatment options are currently limited, new agents under clinical development may offer hope.


Assuntos
Antifúngicos/farmacologia , Aspergilose/imunologia , Aspergillus fumigatus/imunologia , Infecções por Coronavirus/imunologia , Farmacorresistência Fúngica Múltipla/imunologia , Pneumonia Viral/imunologia , Triazóis/farmacologia , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergilose/microbiologia , Aspergillus fumigatus/efeitos dos fármacos , Betacoronavirus/imunologia , Exposição Ambiental , Humanos , Hospedeiro Imunocomprometido/imunologia , Testes de Sensibilidade Microbiana , Pandemias , Triazóis/uso terapêutico
13.
Mikrobiyol Bul ; 54(2): 291-305, 2020 Apr.
Artigo em Turco | MEDLINE | ID: mdl-32723284

RESUMO

Aspergillus fumigatus can cause different clinical manifestations including chronic pulmonary infections, as well as invasive aspergillosis which is highly mortal in the immunocompromised host. Azole antifungal drugs, voriconazole in particular, are the first-line recommended therapeutic regimen. Azoles inhibit 14-α demethylase enzyme encoded by the cyp51A gene. In recent years, increased azole resistance is observed among environmental and clinical A.fumigatus isolates. Two different mechanisms have been proposed for the development of resistance. The first one is the triggering of resistance as a result of long-term clinical azole use. Point mutations in cyp51A gene are generally responsible for this type of azole resistance. The second mechanism is incidental environmental azole exposure due to the use of azoles as agricultural fungicides. Contact with azoles for extended periods and at varying concentrations causes selective pressure and mutations on sporulating A.fumigatus. Since the resistant strains may persist in nature, susceptible individuals may be infected by acquisition of these strains from the environment. When genotypically examined, the cyp51A gene of the resistant isolates of environmental origin specifically presents with a tandem repeat in the promoter region in addition to the point mutation in codon 98 (TR34/L98H). The aim of this study was to investigate azole resistance rates in A.fumigatus strains isolated from clinical specimens and landscaping areas around Hacettepe University Faculty of Medicine Hospital by phenotypical and genotypical methods. Agar screening test was used as the initial test to detect azole resistance in isolates identified as A.fumigatus sensu stricto according to thermotolerance test results. For all strains that grew on any of the azole containing plates in agar screening test, minimum inhibitory concentration (MIC) values were determined by "European Committee on Antimicrobial Susceptibilitiy Testing" reference microdilution method for the confirmation of the resistance. In addition, cyp51A gene sequence was investigated in selected isolates and mutation analysis was performed. A total of 483 clinical and 65 environmental A.fumigatus sensu stricto isolates were included in the study. The first group of clinical isolates consisted of 215 strains isolated in 1997-2015, revived from stock and tested. The second group consisted of 268 strains belonging to the time period of 2016-2018, during which routine azole agar screening tests were performed for A.fumigatus isolates. When all isolates (n= 483) were evaluated together, 11 isolates (1 before 2015 and 10 between 2016-2018), were found to be resistant to itraconazole (2.3%). None of the mutations previously reported to be associated with azole resistance in Aspergillus strains that were detected in cyp51A sequence analysis, However, polymorphisms which are not (yet) fully elucidated in relation to the resistance (Y46F, G89G, V172M, T248N, E255D, L358L, K427E, C454C, Y431D and Q141H in one strain) were shown to exist in resistant isolates. These results have shown that the rate of azole resistance among clinical A.fumigatus isolates was low (2.3%) in our center. Further studies are required to demonstrate the possible role of the detected polymorphisms on azole resistance and to clarify other mechanisms related with high azole MIC values. In addition, since high azole resistance has been reported from one region in our country, it has been concluded that multicenter studies are required to determine the azole resistance status and the range for the azole resistance ratio in different regions and to reveal resistance mutations that may be specific to our country.


Assuntos
Antifúngicos , Aspergilose , Aspergillus fumigatus , Farmacorresistência Fúngica , Antifúngicos/farmacologia , Aspergilose/microbiologia , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Farmacorresistência Fúngica/genética , Microbiologia Ambiental , Humanos , Testes de Sensibilidade Microbiana
14.
Int J Nanomedicine ; 15: 3983-3999, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606660

RESUMO

Introduction: In recent years, the use of cost-effective, multifunctional, environmentally friendly and simple prepared nanomaterials/nanoparticles have been emerged considerably. In this manner, different synthesizing methods were reported and optimized, but there is still lack of a comprehensive method with multifunctional properties. Materials and Methods: In this study, we aim to synthesis the copper oxide nanoparticles using Achillea millefolium leaf extracts for the first time. Catalytic activity was investigated by in situ azide alkyne cycloaddition click and also A3 coupling reaction, and optimized in terms of temperature, solvent, and time of the reaction. Furthermore, the photocatalytic activity of the synthesized nanoparticles was screened in terms of degradation methylene blue dye. Biological activity of the synthesized nanoparticles was evaluated in terms of antibacterial and anti-fungal assessments against Staphylococcus aureus, M. tuberculosis, E. coli, K. pneumoniae, P. mirabili, C. diphtheriae and S. pyogenes bacteria's and G. albicans, A. flavus, M. canis and G. glabrata fungus. In the next step, the biosynthesized CuO-NPs were screened by MTT and NTU assays. Results: Based on our knowledge, this is a comprehensive study on the catalytic and biological activity of copper oxide nanoparticles synthesizing from Achillea millefolium, which presents great and significant results (in both catalytic and biological activities) based on a simple and green procedure. Conclusion: Comprehensive biomedical and catalytic investigation of the biosynthesized CuO-NPs showed the mentioned method leads to synthesis of more eco-friendly nanoparticles. The in vitro studies showed promising and considerable results, and due to the great stability of these nanoparticles in a green media, effective biological activity considered as an advantageous.


Assuntos
Tecnologia Biomédica , Cobre/farmacologia , Nanopartículas Metálicas/química , Achillea/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Catálise , Sobrevivência Celular/efeitos dos fármacos , Reação de Cicloadição , Fungos/efeitos dos fármacos , Células Hep G2 , Humanos , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Solventes/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo , Difração de Raios X
15.
Int J Nanomedicine ; 15: 4351-4362, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606682

RESUMO

Purpose: The present study synthesized silver nanoparticles (AgNPs) using the aqueous extract of a traditional medicinal product consisting of an oleoresin (a combination of macromolecules of carbohydrates and proteins) exuded from the rhizome of the plant Ferula foetida (asafoetida gum) and evaluated its biological properties. Materials and Methods: The silver nanoparticles synthesized using asafoetida gum (As-AgNPs) were characterized using UV/Vis spectroscopy, fourier infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM) and EADX. The cytotoxicity and antimicrobial activity As-AgNPs were evaluated against MCF-7 cell lines and selected microbial pathogens, respectively. Results: The synthesized silver nanoparticles were crystalline in nature with a spherical shape. The average particle size was 5.6-8.6 nm. The cytotoxicity of the synthesized As-AgNPs was evaluated against MCF-7 cell lines, and the As-AgNPs were found to be effective in inhibiting the multiplication of cancer cells. The As-AgNPs exhibited significant antimicrobial activity towards E. coli, K. pneumoniae and C. albicans. The MIC of the synthesized As-AgNPs was 7.80 µg/mL for E. coli ATCC 25922, Salmonella sp. WS50- and S. typhi; 15.60 µg/mL for S. typhimurium and S. aureus WS10, and 31.20 µg/mL for K. pneumoniae and S. aureus ATCC 43300-MRSA. In addition, MIC values of 15.60 µg/mL for C. albicans ATCC8436 and 31.20 µg/mL for C. krusei ATCC6258 were obtained. Conclusion: As asafoetida is a good traditional medicine, its involvement in the synthesis of AgNPs led the silver nanoparticles to exhibit good cytotoxic and antimicrobial effects.


Assuntos
Anti-Infecciosos/farmacologia , Ferula/química , Nanopartículas Metálicas/química , Gomas Vegetais/química , Prata/farmacologia , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Células MCF-7 , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Extratos Vegetais/química , Staphylococcus aureus/efeitos dos fármacos , Difração de Raios X
16.
Mycoses ; 63(8): 771-778, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32609906

RESUMO

BACKGROUND: Emergence of coronavirus disease 2019 (COVID-19) is a major healthcare threat. Apparently, the novel coronavirus (SARS-CoV-2) is armed by special abilities to spread and dysregulate the immune mechanisms. The likelihood of oropharyngeal candidiasis (OPC) development in COVID-19 patients with a list of attributable risk factors for oral infections has not yet been investigated. OBJECTIVES: We here aim to investigate the prevalence, causative agents and antifungal susceptibility pattern of OPC in Iranian COVID-19 patients. PATIENTS AND METHODS: A total of 53 hospitalised COVID-19 patients with OPC were studied. Relevant clinical data were mined. Strain identification was performed by 21-plex PCR and sequencing of the internal transcribed spacer region (ITS1-5.8S-ITS2). Antifungal susceptibility testing to fluconazole, itraconazole, voriconazole, amphotericin B, caspofungin, micafungin and anidulafungin was performed according to the CLSI broth dilution method. RESULTS: In 53 COVID-19 patients with OPC, cardiovascular diseases (52.83%) and diabetes (37.7%) were the principal underlying conditions. The most common risk factor was lymphopaenia (71%). In total, 65 Candida isolates causing OPC were recovered. C albicans (70.7%) was the most common, followed by C glabrata (10.7%), C dubliniensis (9.2%), C parapsilosis sensu stricto (4.6%), C tropicalis (3%) and Pichia kudriavzevii (=C krusei, 1.5%). Majority of the Candida isolates were susceptible to all three classes of antifungal drugs. CONCLUSION: Our data clarified some concerns regarding the occurrence of OPC in Iranian COVID-19 patients. Further studies should be conducted to design an appropriate prophylaxis programme and improve management of OPC in critically ill COVID-19 patients.


Assuntos
Antifúngicos/farmacologia , Candida/classificação , Candidíase Bucal/complicações , Infecções por Coronavirus/complicações , Pneumonia Viral/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Candida/efeitos dos fármacos , Candida/genética , Candidíase Bucal/microbiologia , Infecções por Coronavirus/epidemiologia , Feminino , Humanos , Irã (Geográfico) , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Pandemias , Fenótipo , Pneumonia Viral/epidemiologia , Fatores de Tempo
17.
PLoS Genet ; 16(7): e1008908, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32639995

RESUMO

The human fungal pathogen Candida albicans is constantly exposed to environmental challenges impacting the cell wall. Signaling pathways coordinate stress adaptation and are essential for commensalism and virulence. The transcription factors Sko1, Cas5, and Rlm1 control the response to cell wall stress caused by the antifungal drug caspofungin. Here, we expand the Sko1 and Rlm1 transcriptional circuit and demonstrate that Rlm1 activates Sko1 cell wall stress signaling. Caspofungin-induced transcription of SKO1 and several Sko1-dependent cell wall integrity genes are attenuated in an rlm1Δ/Δ mutant strain when compared to the treated wild-type strain but not in a cas5Δ/Δ mutant strain. Genome-wide chromatin immunoprecipitation (ChIP-seq) results revealed numerous Sko1 and Rlm1 directly bound target genes in the presence of caspofungin that were undetected in previous gene expression studies. Notable targets include genes involved in cell wall integrity, osmolarity, and cellular aggregation, as well as several uncharacterized genes. Interestingly, we found that Rlm1 does not bind to the upstream intergenic region of SKO1 in the presence of caspofungin, indicating that Rlm1 indirectly controls caspofungin-induced SKO1 transcription. In addition, we discovered that caspofungin-induced SKO1 transcription occurs through self-activation. Based on our ChIP-seq data, we also discovered an Rlm1 consensus motif unique to C. albicans. For Sko1, we found a consensus motif similar to the known Sko1 motif for Saccharomyces cerevisiae. Growth assays showed that SKO1 overexpression suppressed caspofungin hypersensitivity in an rlm1Δ/Δ mutant strain. In addition, overexpression of the glycerol phosphatase, RHR2, suppressed caspofungin hypersensitivity specifically in a sko1Δ/Δ mutant strain. Our findings link the Sko1 and Rlm1 signaling pathways, identify new biological roles for Sko1 and Rlm1, and highlight the complex dynamics underlying cell wall signaling.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/genética , Candida albicans/efeitos dos fármacos , Caspofungina/farmacologia , Proteínas de Domínio MADS/genética , Proteínas Repressoras/genética , Proteínas de Saccharomyces cerevisiae/genética , Antifúngicos/farmacologia , Candida albicans/genética , Candida albicans/patogenicidade , Parede Celular/efeitos dos fármacos , Parede Celular/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Humanos , Fosforilação/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/genética
18.
Curr Opin Infect Dis ; 33(4): 290-297, 2020 08.
Artigo em Inglês | MEDLINE | ID: covidwho-641651

RESUMO

PURPOSE OF REVIEW: Although clinical outcomes in the treatment of aspergillosis have markedly improved with the availability of newer triazoles, the development of resistance to these antifungals, especially in Aspergillus fumigatus, is a growing concern. The purpose of this review is to provide an update on azole resistance mechanisms and their epidemiology in A. fumigatus, the clinical implications of azole resistance, and to discuss future treatment options against azole-resistant aspergillosis. RECENT FINDINGS: Resistance may develop through either patient or environmental azole exposure. Environmental exposure is the most prevalent means of resistance development, and these isolates can cause disease in various at-risk groups, which now include those with influenza, and potentially COVID-19. Although current treatment options are limited, newer therapies are in clinical development. These include agents with novel mechanisms of action which have in vitro and in vivo activity against azole-resistant A. fumigatus. SUMMARY: Azole-resistant A. fumigatus is an emerging threat that hampers our ability to successfully treat patients with aspergillosis. Certain geographic regions and patient populations appear to be at increased risk for this pathogen. As new patient groups are increasingly recognized to be at increased risk for invasive aspergillosis, studies to define the epidemiology and management of azole-resistant A. fumigatus are critically needed. While treatment options are currently limited, new agents under clinical development may offer hope.


Assuntos
Antifúngicos/farmacologia , Aspergilose/imunologia , Aspergillus fumigatus/imunologia , Infecções por Coronavirus/imunologia , Farmacorresistência Fúngica Múltipla/imunologia , Pneumonia Viral/imunologia , Triazóis/farmacologia , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergilose/microbiologia , Aspergillus fumigatus/efeitos dos fármacos , Betacoronavirus/imunologia , Exposição Ambiental , Humanos , Hospedeiro Imunocomprometido/imunologia , Testes de Sensibilidade Microbiana , Pandemias , Triazóis/uso terapêutico
19.
J Environ Sci Health B ; 55(9): 835-843, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32657210

RESUMO

Aflatoxins produced by Aspergillus parasiticus are toxic and carcinogenic metabolites. The biosynthesis of this mycotoxins is a complex process and involves at least 30 genes clustered within an approximately 82 kB gene cluster. In the present study, the effect of Capsicum chinense and Piper nigrum fruits on Aspergillus parasiticus growth and aflatoxin production were studied in relation to the expression of aflD, aflM, aflR, and aflS four; key genes of aflatoxins biosynthesis pathway. GC-EIMS analysis identified capsaicin (66,107 µg g-1) and piperine (1,138 µg g-1) as the most abundant compounds in C. chinense and P. nigrum fruits, respectively. The antifungal and anti-aflatoxigenic assays showed that C. chinense, P. nigrum, capsaicin, and piperine inhibited A. parasiticus growth and aflatoxins production in a dose-dependent manner. The piperine at 300 µg mL-1 produced higher radial growth inhibition (89%) and aflatoxin production inhibition (69%). The expression of aflatoxin biosynthetic genes was evaluated by quantitative real-time PCR (qRT-PCR) and revealed that aflatoxin inhibition occurring via downregulating the aflS and aflR, and subsequently aflD and aflM genes. These results will improve our understanding of the mechanism of aflatoxin regulation by C. chinense, P. nigrum, capsaicin, and piperine, and provides a reference for further study.


Assuntos
Aflatoxinas/metabolismo , Aspergillus/efeitos dos fármacos , Capsicum/química , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Piper nigrum/química , Aflatoxinas/genética , Alcaloides/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Aspergillus/genética , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Benzodioxóis/farmacologia , Vias Biossintéticas , Capsaicina/farmacocinética , Proteínas de Ligação a DNA/genética , Frutas/química , Proteínas Fúngicas/genética , Genes Fúngicos , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Fatores de Transcrição/genética
20.
Int J Food Microbiol ; 330: 108766, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32659522

RESUMO

The aim of the study was to explore the antifungal and aflatoxin B1 inhibitory efficacy of nanoencapsulated antifungal formulation. Mixture design response surface methodology (RSM) was utilized to design the antifungal formulation (SBC 4:1:1) based on the combination of chemically characterized Ocimum sanctum (S), O. basilicum (B), and O. canum (C) against Aspergillus flavus. The SBC was incorporated inside the chitosan nanomatrix (Ne-SBC) using an ultrasonic probe (40 kHz) and interactions were confirmed by SEM, FTIR and XRD analysis. The results showed that the Ne-SBC possessed enhanced antifungal and aflatoxin B1 inhibitory effect over the free form of SBC. The biochemical and in silico results indicate that the antifungal and aflatoxin B1 inhibitory effect was related to perturbance in the plasma membrane function (ergosterol biosynthesis and membrane cation) mitochondrial membrane potential, C-sources utilization, antioxidant defense system, and the targeted gene products Erg 28, cytochrome c oxidase subunit Va, and Nor-1. In-situ observation revealed that Ne-SBC effectively protects the Avena sativa seeds from A. flavus and AFB1 contamination and preserves its sensory profile. The findings suggest that the fabrication of SBC inside the chitosan nano-matrix has promising use in the food industries as an antifungal agent.


Assuntos
Aflatoxina B1/antagonistas & inibidores , Antifúngicos/farmacologia , Microbiologia de Alimentos , Ocimum/química , Óleos Voláteis/farmacologia , Aflatoxina B1/metabolismo , Antifúngicos/química , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/metabolismo , Quitosana/química , Quitosana/farmacologia , Composição de Medicamentos , Ocimum/classificação , Óleos Voláteis/química , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Sementes/microbiologia
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