Search

Objective: The aim of this study is to determine the distribution of samples exhibiting Candida growth among the blood cultures, and the antifungal susceptibility. Methods: The retrospective study was conducted in Samsun Training and Research Hospital, Samsun, Turkey from January to December, 2018 and comprised immunosuppressed patients with sepsis. Ethical approval was obtained and consent was taken from all patients. Yeast growths were typed by means of colony morphology, germ tube formation and the VITEK 2 system. Their susceptibilities tests were determined using the same automatized system. Resistance strains were also tested using the dilution method. Results: Of the 50 patients, 19(38%) were females and 31(62%) were males. The overall mean age was 60.84 ± 22.05 years. 31 (62%) of the samples were received from intensive care units, 14 (28%) from the palliative care unit, and five from other inpatients. In our study, most common among our isolates was C. albicans, and C. parapsiosis was most common among non-albicans species. Resistance to antifungals was observed in 28% of Candida isolates. Of the total isolates, %10 were found to be naturally resistant to fluconazole, 8% to voriconazole, 4% to flucytosine, and amphotericin B. The high resistance rate for fluconazole in Candida species is noteworthy. The findings obtained through both the dilution method and the automatized system were consistent. Continuou....

Bionanotechnology has increasingly gained attention in biomedical fields as antifungal and antibiofilm agents. In this study, biosynthesized silver nanoparticles (bio-AgNPs) using aqueous Eucalyptus camaldulensis leaf extract were successfully performed by a one-step green approach. Spherical-shaped nanoparticles, approximately 8.65 nm, exhibited noncytotoxicity to erythrocytes, HeLa, and HaCaT cells. The synthesized nanoparticles showed strong fungicidal activity ranging from 0.5 to 1 µg/ml. The nanoparticles affected Candida adhesion and invasion into host cells by reduced germ tube formation and hydrolytic enzyme secretion. Inhibitory effects of bio-AgNPs on Candida biofilms were evaluated by the prevention of yeast-to-hyphal transition. A decrease in cell viability within mature biofilm demonstrated the ability of bio-AgNPs to penetrate into the extracellular matrix and destroy yeast cell morphology, leading to cell death. Molecular biology study on biofilms confirmed downregulation in the expression of genes ALS3, HWP1, ECE1, EFG1, TEC1, ZAP1, encoding hyphal growth and biofilm development and PLB2, LIP9, SAP4, involved in hydrolytic enzymes. In addition to candida treatment, the bio-AgNPs could be applied as an antioxidant to protect against oxidative stress-related human diseases. The findings concluded that bio-AgNPs could be used as an antifungal agent for candida treatment, as well as be incorporated in medical devices to prevent biofilm formation.

The increased resistance/tolerance of Candida infections to antimicrobial treatment can be attributed to biofilm-associated cells. A way to overcome this situation is to re-purpose non-anti-fungal drugs that could be active against fungi. We have explored the potential of a small library of eighteen non-antifungal drugs used in different human diseases. Candida albicans was cultured in the presence and absence of different concentrations of these drugs. Subsequently, inhibition of growth, germ tube formation, adhesion, and biofilm development were studied. Out of eighteen drug molecules, six showed a reduction in planktonic and biofilm growth in a dose-dependent manner and three drugs inhibited germ tube formation. This study shows the potential of non-antifungal drugs for the development of new anti-Candida agents.

Background: Otomycosis is a superficial, sub-acute or chronic infection of the external auditory canal. It is worldwide in distribution with a higher prevalence in the hot, humid, and dusty areas of the tropics and subtropics. A wide variety of fungi can cause Otomycosis. Objectives: To determine the demographic profile & spectrum of fungi involved in Otomycosis in saurashtra & Kutch region of Gujarat. Materials and Methods: A retrospective study of 101 clinically suspected cases of otomycosis were conducted. The sample are taken by two sterile cotton swabs comprised of secretions, pus and debris from the external auditory canal. Direct microscopic examination by 10% KOH, Gram stain & cuiture on Sabouraud Dextrose Agar medium was done. Identification of fungi done by lacto phenol cotton blue, GERM TUBE TEST & growth on CORNMEAL AGAR and Hichrome Media ysed for species identification. Result: Out of 101 cases, 76(75.24%) were Culture Positive and 74(73.26%) were KOH positive. Out of 74 KOH positive, 65(87.83%) cases were culture positive. Predominantly males (52.6%) were affected. The most affected age group is 31-40 yrs of age (23.68%). Aspergillus niger (52.63%) was the predominant species isolated followed by Aspergillus flavus (36.84%), Candida spp, Penicillium spp. & Rhizopus spp. The disease is predominantly unilateral. Conclusion: Otomycosis should be suspected clinically and should be confirmed by laboratory diagnosis to prevent unnecessary use of antibiotics & there by antibiotic resistance. Mycological diagnosis is important to differentiated from bacterial infection, since symptoms (pruritus, otalgia, otorrhea and hypacusis) are not specific. Keywords: Aspergillus, Otomycosis.

Inhibition of B. cinerea by alginate (Alg) / cajuput essential oil (Caj) at different concentration (0%, 0.25%, 0.5%, 0.75%) and the composite’s surface properties were investigated. Among the samples, the treated spore with Caj 0.75% showed the lowest germination percentage and germ tube length. The regarded antifungal action was confirmed by observing the changes of membrane integrity stained with propidium iodide under fluorescence microscope. Moreover, the film composite roughness was characterized which Caj affected significantly (P

Maydis leaf blight, caused by Bipolaris maydis, is a serious foliar disease of maize distributed widely throughout the world and causing significant yield losses. The study aimed to describe stages of the infection process of B. maydis on maize leaves. The adaxial surfaces of maize leaves were inoculated with a conidial suspension of B. maydis and leaf samples were collected from 24 to 120 hrs after inoculation (hai). At 24 hai, the germ tubes from the germinated conidia and fungal hyphae attempted to penetrate the leaf through the stomata. These results provide new insight into the infection process of B. maydis on maize leaves and may contribute to the development of more effective management of maydis leaf blight.

Introduction and Objectives: Antibiotics, immunodeficiencies and advances in medical practices have all contributed to increased incidence in fungal infections. In recent times Non albicans Candida species are increasingly being isolated from clinical specimens. The present study was aimed at the characterization and antifungal susceptibility of Non albicans Candida species from clinical specimens received in Microbiology Laboratory for one year from June 2015–May 2016. Materials and Methods: A total of 181 Non albicans Candida isolates were included in the study. Candida was identified from clinical samples by gram stain, culture on Saboraud’s Dextrose Agar (SDA) and germ tube test. The organisms were further speciated by cornmeal agar morphology, sugar assimilation and fermentation tests and growth on CHROM agar (Himedia). Antifungal sensitivity was performed by using disc diffusion method as per CLSI guidelines. Results: The most common isolate was Candida tropicalis (59.11%) followed by C.glabrata (28.18%), C.parapsilosis (8.83%) and C.krusei (3.88%). Highest number of isolates were from urine (74/181). Resistance to Fluconazole in clinical isolates of C.tropicalis has increased. C.krusei was the most resistant species. Conclusion: Use of CHROM agar is rapid, simple and cost effective compared to time consuming technically demanding expensive conventional methods. Antifungal susceptibility testing has to be carried out before starting therapy because of varying susceptibility pattern in different species of Candida. Keywords: Non albicans Candida species, Candidiasis, CHROM agar.

Aim Candida-associated fungal infections are prevalent in hospitalized and immune-compromised patients. Their biofilm architecture and high rate of antifungal resistance make treatment challenging. Eucalyptol (EPTL), a monoterpene majorly present in the essential oil of eucalyptus is well known for curing respiratory infections. Hence, the present study investigated the anti-biofilm efficacy of EPTL against the laboratory strains and clinical isolates of Candida to delineate its mode of action. Methods The effect of EPTL on the viability, biofilm formation, and mature biofilm of Candida strains was studied. Furthermore, its effect on cell cycle arrest, mitochondrial membrane potential (MMP), ROS generation, germ tube formation, ergosterol content and transcriptional expression of selected genes was also investigated. Results EPTL exhibited anti-biofilm activity against mature and developing biofilm of Candida albicans and Candida glabrata along with their clinical isolates. The biochemical components and enzyme activity were differentially modulated in EPTL-treated biofilm extracellular matrix. EPTL generated ROS and arrested cell cycle at the G1 /S phase in both the species, while altered MMP was recorded in C. glabrata. Transcriptional analysis evidenced for differential gene expression of selected ABC transporters, secreted hydrolytic enzymes, and cell wall biogenesis in C. albicans/C. glabrata upon treating with EPTL. Conclusion The current data on anti-biofilm activity of EPTL establish its candidacy for drug development or as an adjuvant with existing antifungal formulations. Significance and impact of the study Present investigation elucidates the mode of action of Eucalyptol as antifungal agent and would stand as a candidate for management of topical fungal infection.

Fungal growth often appears in a surrounding where water and nutrients are scarce. The impact of this environment during sporogenesis on subsequent growth is often neglected. This study investigates the effect of water availability during sporogenesis on subsequent early growth. Therefore, a carbon-depleted substrate was constructed. Humidity is then the only parameter of interest. The water conditions during sporogenesis, and during subsequent growth, were varied. This is a stressing environment: no carbon source is present, and water provided solely via the vapour. The lag time, t l, and initial growth rate, μ fp, of the germ tubes were monitored. The effect of a w history on germination and initial growth depends on the RH of the environment. Only at low RH do spores produced at low a w have a smaller t l and higher μ fp compared to those grown at high a w. This result was remarkably pronounced when the substrate was also made hydrophobic: growth only occurred when spores were developed at low a w and placed in high RH. Spores grown on lowered a w attract more water. It is hypothesized that this attraction affects subsequent growth behaviour, and is the reason why growth on hydrophobic glass only prevails in the condition of high RH and lowered a w history. We demonstrate the influence of cultivation conditions on germination, which becomes more pronounced in a more desiccated environment.

Fluorescence microscopy and qPCR-based pathogen tracking tools were developed to elucidate the growth and development of Puccinia graminis f. sp. tritici on leaves of nonhost plant (rice: Oryza sativa L.). Stem rust race-Puccinia graminis f. sp. tritici 40A was identified using Internal Transcribed Spacer (ITS) sequences and gene sequences coding for hypothetical protein (PGTG_08233_hypothetical protein, HP). A reliable qPCR-based quantitation assay was developed for stem rust fungus exploiting HP primers that yielded 377-bp amplicon in conventional PCR and a forma specialis-specific 146 bp in qPCR with a detection sensitivity of 250-fg genomic DNA. The fungal cell wall N-acetyl-glucosamine was green fluorescence labelled and visualized on propidium iodide-stained nonhost leaf. This technique along with scanning electron microscopy allowed imaging of various developmental structures of Puccinia graminis f. sp. tritici 40A on plant epiphytic and endophytic niches. The microscopy coupled with qPCR-based pathogen load estimation revealed that the nonhost (rice) and host (wheat) phyllosphere surface supported uredospore germination, germ tube formation, hyphal elongation, epiphytic growth, stomatal entry and endophytic growth of fungus in an identical manner. However, the nonhost plant did not show any sign of rusting caused by uredospore production, which instead displayed induced H2O2 accumulation, on leaf. Development of qPCR-based Puccinia quantitation and green fluorescent tag-based qualitative assessment of Puccini proliferation will facilitate nonhost resistance phenotyping not only in rice but also in other nonhost plants of stem rust pathogen.

Anthracnose disease is caused by the ascomycetes fungal speciesColletotrichum,which is responsible for heavy yield losses in chilli and tomato worldwide. Conventionally, harmful pesticides are used to contain anthracnose disease with limited success. In this study, we assessed the potential of Host-Induced Gene Silencing (HIGS) approach to target theColletotrichum gloeosporioides COM1(CgCOM1) developmental gene involved in the fungal conidial and appressorium formation, to restrict fungal infection in chilli and tomato fruits. For this study, we have developed stable transgenic lines of chilli and tomato expressingCgCOM1-RNAi construct employingAgrobacterium-mediated transformation. Transgenic plants were characterized by molecular and gene expression analyses. Production of specificCgCOM1siRNA in transgenic chilli and tomato RNAi lines was confirmed by stem-loop RT-PCR. Fungal challenge assays on leaves and fruits showed that the transgenic lines were resistant to anthracnose disease-causingC. gloeosporioidesin comparison to wild type and empty-vector control plants. RT-qPCR analyses in transgenic lines revealed barely anyCgCOM1transcripts in the C.gloeosporioidesinfected tissues, indicating near complete silencing ofCgCOM1gene expression in the pathogen. Microscopic examination of theCg-challenged leaves of chilli-CgCOM1i lines revealed highly suppressed conidial germination, germ tube development, appressoria formation and mycelial growth ofC. gloeosporioides, resulting in reduced infection of plant tissues. These results demonstrated highly efficient use of HIGS in silencing the expression of essential fungal developmental genes to inhibit the growth of pathogenic fungi, thus providing a highly precise approach to arrest the spread of disease.

The transition of Candida albicans from yeast to hyphae cause the attachment to epithelial cells, forming biofilm and invasion. Therefore, the effect of Pediococcus acidilactici on morphogenesis and pathogenesis of C. albicans were examined. Inhibitory activity of P. acidilactici on Candida species growth was investigated and inhibition of C. albicans biofilm formation was measured by XTT method. Also, expression of seven genes as: Agglutinin-like protein 1 (ALS1,3), hyphal cell-wall protein (HWP1), secreted aspartyl proteinase (SAP4,6), Enhanced filamentous growth 1 (EFG1) and Enhanced activated protein 1 (EAP1) were studied by RT-PCR with different concentrations of P. acidilactici. The experimental activity of this probiotic bacterium was evaluated in an animal model by culture and histopathological methods. P. acidilactici inhibited the growth of Candida species at concentrations of 8-512 µg/mL (approximately 8 × 106 to 5 × 108 CFU/ml). This probiotic bacterium inhibited the germ tube and biofilm formation in a dose-dependent manner. RT-PCR analysis showed a reduction in genes expression. The P. acidilactici reduced the CFUs in mice receiving this probiotic bacterium. Histopathological analyses showed that Candida colonization was diminished in mice following the administration of probiotic. Since the wide range of antifungal activity of this bacterium bacterium, it can be used to manage oral candidiasis.

Background: The recent change in the epidemiology of Candidiasis with emergence of non albicans Candida species as the predominant agents is of serious concern globally. Speciation of Candida is very important since many of these species are associated with resistance to the common antifungal agents and often lead to treatment failures. The existing conventional methods for speciation are time consuming and tedious. We attempt to evaluate the performance of the four phenotypic methods for speciation of Candida with molecular method. Materials and Methods: This observational study was conducted on all the clinically significant isolates of Candida species obtained from various specimens for a period of 2 years. Speciation was done by phenotypic methods which include conventional germ tube test, chromogenic medium (HiCrome agar), corn meal agar and automated method-Vitek-2 system. Molecular speciation was done by multiplex polymerase chain reaction (PCR). Performance of phenotypic methods is evaluated with results of PCR as gold standard. Results: During the study period, a total of 80 isolates of Candida species from various clinical samples were enrolled in the study. Molecular speciation identified 25 C.albicans (31.25%) which was the most common species, followed by 23 C.tropicalis(28.75%), 13 C.parapsilosis (16.25%), 12 C.krusei (15%), 4 C.pelliculosa (5%), 2 C.auris (2.5%) and one C.glabrata (1.25%). Comparing with molecular method, the sensitivity and specificity of chromogenic medium, corn meal agar and Vitek-2 compact system was found to be 91.25% and 100%; 83.75% and 100% and both 100% respectively. Interpretation and Conclusion: Overall non albicans Candida spp predominated in the present study. Among the various phenotypic methods studied performance of HiCrome agar was very good and has the advantage of speciation directly from samples where as that of Vitek 2 Compact was excellent and but requires pure growth. Conventional methods failed to identify many

The aim of this study was to evaluate the phytochemical constituents, antioxidant, antifungal, and anti-virulence activities of traditionally used Mezoneuron benthamianum leaves. Extracts were prepared using acetone and methanol, and the preliminary phytochemical screening was performed. The antioxidant activity was studied using the DPPH method. Anti-Candida albicans activity was established and the effect on the germ tube and phospholipase production, as well as on the host cell adherence was assessed. The extracts showed the presence of anthraquinones, cardiac glycosides, flavonoids, reducing sugars, saponins, steroids, tannins, and terpenoids. Gallic acid and trans-resveratrol were among the predominant phytochemicals found in M. benthamianum. The crude extracts presented significantly higher antioxidant activity than the ascorbic acid standard. At 0.39 mg/mL, acetone extract inhibited the growth of Candida albicans. At lower concentrations (200-50 µg/mL), it significantly inhibited the adherence ability (up to 51%), formation of hyphae (up to 65%), and the production of phospholipase. In conclusion, at high concentrations, M. benthamianum kills C. albicans, and at lower concentrations, it can inhibit the virulence properties of this pathogen. This study on crude extract validates the traditional use of this plant. However, further research is required to establish the anti-virulence activity of the two compounds and their therapeutic potential.

Background: menopausal women are a predisposing factor for candidiasis. In menopausal women humoral changes occur in the body and pH in the vagina. This change in pH can lead to increased fungal growth of Candida albicans. Purpose: this study aims to identify the fungus Candida albicans in urine samples of menopausal women at Banjar Taman, Darmasaba Village, Abiansemal District, Badung Regency. Method: this research was conducted descriptively with a cross sectional approach. The sampling technique with Non-probality sampling is Purposive Sampling. Urine samples were cultured on SDA media. Result: the growing colonies were identified macroscopically and microscopically and tested germ tube. Identification results showed that from 33 urine samples, 5 (15%) were positive, there was a Candida albicans fungus which showed protruding from the surface of the media, the surface on the colonies was smooth, yellowish white, and had a yeast odor. On microscopic examination it was found that yeast, pseudohifa, clamidospora, blastospora and germ tube. Conclusion: the percentage value shows the occurrence of Candida albicans fungi in the urine of menopausal women in Banjar Taman, Darmasaba Village, Abiansemal Subdistrict, Badung Regency so that menopausal women are expected to always maintain personal hygiene and routinely conduct microbiological examinations.Keywords: urine, menopausal women, candida albicans

Background and Aim: Candida albicans is a dimorphic fungus that has both yeast and filamentous forms. It is part of the normal flora in the oral and genital areas of mammals. One factor for the pathogenicity of C. albicans is its ability to switch from yeast to hyphae. The hyphal form adheres and penetrates tissues more readily than the yeast form and produces biofilms that are associated with chronic infection. Biofilms are protective niches that enable microorganisms to be more resistant to antibiotic treatment, thus allowing for persistent infection. The first stage in the transition from yeast to hyphae involves the formation of a germ tube, and this transition is triggered by interactions with host cells. Germ tube formation is dependent on serum, pH, temperature, and quorum-sensing molecules (QSMs). Farnesol, which is a QSM in C. albicans, can prevent yeast to hyphae conversion and inhibits the growth of fungal biofilm. Lyticase is a synergistic enzyme complex that catalyzes yeast cell lysis by β-1,3-glucanase and is a highly specific alkaline protease that produces protoplasts or spheroplasts. This study investigated the effect of farnesol and lyticase on the formation of C. albicans biofilms. Materials and Methods: C. albicans ATCC 2091 was cultivated on liquid and solid Sabouraud media. The presence of C. albicans was confirmed using HiCrome Candida Agar chromogenic medium. Enzyme activities were assayed using a HiCandida Identification Kit. The morphology and densitometry parameters of C. albicans biofilms were considered in the presence of farnesol (Sigma-Aldrich, Germany), lyticase (from Arthrobacter luteus; Sigma-Aldrich, Germany), and farnesol–lyticase. Results: This study shows that both farnesol and lyticase possess antifungal activity against C. albicans biofilms. A significant difference among treatment groups (p

Context: Candida is a yeast-like fungus, and it causes candidiasis. Since it is commonly encountered in many cases, the need of the hour is for rapid and reliable method for identification of these fungi in tissue sections. Aim: The aim of this study was to evaluate and compare the staining efficacy of calcofluor white (CFW) and acridine orange (AO) for the detection of Candida species in formalin-fixed paraffin-embedded tissue samples of oral squamous cell carcinoma (OSCC) using fluorescence microscopy. Settings and Design: Sample size comprised forty cases of OSCC. Materials and Methods: Before tissue sampling, a swab of the area was taken, it was immediately inoculated on Sabouraud's dextrose agar media and germ tube test was performed for positive cultures for species identification. Tissue sections were obtained from cases of OSCC from the formalin-fixed paraffin-embedded tissue blocks of the same cases in which microbiological assessment was done at the time of tissue sampling, were stained with CFW and AO stain, respectively, and were examined using a fluorescent microscope. Statistical Analysis Used: Descriptive statistics were expressed in numbers and percentage. Independent t-test (unpaired t-test) and Chi-square test were used. P ≤0.05 was taken to be statistically significant. Results: The mean number of microorganisms per high-power field stained by CFW and AO was 6.35 and 2.57, respectively, and a statistically significant difference (P ≤ 0.001) was observed. CFW compared to swab culture gave P = 0.018, which showed a statistically significant association. Conclusions: CFW is a better fluorescent stain when compared to AO to detect Candida species in tissue sections of OSCC cases.

Introduction: Candida albicans, a predominant yeast pathogen can be easily distinguished from other non-albicans species in a diagnostic laboratory based on their property to produce germ tubes using human serum as a routine substrate. As usage of human serum is accompanied with risk of transmission of bloodborne viral infections, several other media were employed by many clinical laboratories. The aim of this study was to evaluate the efficacy of four commonly used non-serum liquid media relative to fresh human serum in germ tube (GT) productivity among various Candida isolates. Materials and Methods: A total of 146 Candida isolates (96 C. albicans; 47 C. tropicalis; 3 C. dubliniensis) identified by conventional methods were assessed for germ tube production in five types of media namely peptone water, Mueller Hinton broth, Trypticase soy broth, Brain Heart infusion broth and fresh human serum . Results obtained in different media for germ tube production in all Candida isolates were analysed for sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy. Results: All the Candida isolates showed 100% specificity and PPV in all the five-liquid media. Highest performance in germ tube production (96%) in C. albicans isolates was found in Trypticase soy broth followed by fresh human serum (95%). Trypticase soy broth was shown to have 96% sensitivity and 97% accuracy for germ tube formation comparable to human serum with 95% sensitivity and 96.5% accuracy. Conclusion: Trypticase soy broth can be suggested as a choice medium for GT production in diagnostic mycology. Keywords: Trypticase soy broth, Peptone water germ tube production test sensitivity specificity