Candida-related Infections Research Articles

The Antifungal Effects of Tea Tree Oil as a Potential Therapeutic Candidate for Candida-related Infections in Albino Rats

The Antifungal Effects of Tea Tree Oil as a Potential Therapeutic Candidate for Candida-related Infections in Albino Rats

Comparison of Candida colonization in intensive care unit patients with and without COVID-19: First prospective cohort study from Turkey.

Candida species are the primary cause of fungal infections in intensive care units (ICUs). Despite the increasing prevalence of Candida-related infections, monitoring the progression of these infections from colonization in COVID-19 ICU patients lacks sufficient information. This study aims prospectively to compare 62 COVID-19 and 60 non-COVID-19 ICU patients from admission to discharge in terms of colonization development, rates, isolated Candida species, risk factors, and Candida infections during hospitalization. A total of 1464 samples were collected at specific time intervals from various body sites [mouth, skin (axilla), rectal, and urine]. All samples were inoculated onto CHROMagar Candida and CHROMagar Candida Plus media, and isolates identified using MALDI-TOF MS. COVID-19 patients exhibited significantly higher colonization rates in oral, rectal, and urine samples compared to non-COVID-19 patients, (p<0.05). Among the Candida species, non-albicans Candida was more frequently detected in COVID-19 patients, particularly in oral (75.8%-25%; p<0.001) and rectal regions (74.19% - 46.66%; p<0.05). Colonization with mixed Candida species was also more prevalent in the oropharyngeal region (p<0.05). Mechanical ventilation and corticosteroid use emerged as elevated risk factors among COVID-19 patients (p<0.05). Despite the colonization prevalence, both COVID-19-positive and negative patients exhibited low incidences of Candida infections, with rates of 9.67% (n=6/62) and 6.67% (n=3/60), respectively. Consequently, although Candida colonization rates were higher in COVID-19 ICU patients, there was no significant difference in Candida infection development compared to the non-COVID-19 group. However, the elevated rate of non-albicans Candida isolates highlights potential future infections, particularly given their intrinsic resistance in prophylactic or empirical treatments if needed. Additionally, the high rate of mixed colonization emphasizes the importance of using chromogenic media for routine evaluation.

Changing Epidemiology of Clinical Isolates of Candida Species during the Coronavirus Disease 2019 Pandemic: Data Analysis from a Korean Tertiary Care Hospital for 6 Years (2017-2022).

This study assessed the changes in Candida species distribution and antifungal susceptibility patterns during the coronavirus disease 2019 (COVID-19) pandemic compared with a pre-pandemic period in Korea. We retrospectively investigated the specimen, species type, and antifungal susceptibility of Candida isolates obtained between 2016 and 2022. Data between two periods were compared: 2016-2019 (pre-pandemic) and 2020-2022 (pandemic). We included 11,396 clinical isolates of Candida species (5137 isolates in the pre-pandemic and 6259 isolates in the pandemic). The most prevalent species was Candida albicans (50.4%), followed by Candida glabrata (22.7%), Candida tropicalis (12.5%), and Candida parapsilosis complex (12.5%). Their ranks were unchanged; however, their relative isolation ratios varied during the pandemic, exhibiting differences ranging from 0.4 to 2.5 across species. The incidence of candidemia increased during the pandemic (average 1.79 episodes per 10,000 patient days) compared with pre-pandemic levels (average 1.45 episodes per 10,000 patient days) in both intensive-care-unit (ICU) and non-ICU patients. Additionally, C. parapsilosis complex candidemia increased by 1.6-fold during the pandemic. During the pandemic, C. albicans and C. tropicalis candidemia significantly increased by 1.5- and 1.4-fold in ICU patients. In contrast, C. parapsilosis complex candidemia surged 2.1-fold in non-ICU patients. These species exhibited reduced resistance to fluconazole, voriconazole, caspofungin, and micafungin in the pandemic compared with the pre-pandemic. This study underscores the heightened incidence of Candida-related infections during the COVID-19 pandemic and emphasizes the importance of ongoing surveillance of Candida species epidemiology beyond the pandemic's scope.

Anti-Candida activity and in vitro toxicity screening of antifungals complexed with β-cyclodextrin.

The emergence of resistant fungal species and the toxicity of currently available antifungal drugs are relevant issues that require special consideration. Cyclodextrins inclusion complexes could optimize the antimicrobial activity of such drugs and create a controlled release system with few side effects. This study aimed to assess the in vitro toxicity and antifungal effectiveness of nystatin (Nys) and chlorhexidine (Chx) complexed or not with β-cyclodextrin (βCD). First, a drug toxicity screening was performed through the Artemia salina bioassay. Then, the minimum inhibitory concentrations (MICs) against Candida albicans were determined with the broth microdilution test. After MICs determination, the cytotoxicity of the drugs was evaluated through the methyl-thiazolyl-tetrazolium (MTT) and neutral red (NR) assays and through cell morphology analysis. The PROBIT analysis was used to determine the median lethal concentration (LC50), and the cell viability values were submitted to one-way analysis of variance(ANOVA)/Tukey (α = 0.05). Overall, the βCD-complexed antifungals were less toxic against A.salina than their raw forms, suggesting that inclusion complexes can reduce the toxicity of drugs. The MICs obtained were as follows: Nys 0.5mg/L; Nys:βCD 4mg/L; Chx 4mg/L; and Chx:βCD 8mg/L. Chx showed significant cytotoxicity (MTT: 12.9 ± 9.6%; NR: 10.6 ± 12.5%) and promoted important morphological changes. Cells exposed to the other drugs showed viability above 70% with no cellular damage. These results suggest that antifungals complexed with βCD might be a biocompatible option for the treatment of Candida-related infections.

Impact of the 4th of August Beirut explosion mass casualty incident on a university hospital microbial Flora

BackgroundFollowing the Beirut explosion, our university hospital received at least 350 casualties. Subsequently, infection control standard practices were compromised. Concerns for Multi-Drug Resistant Organisms (MDROs) infections in injured patients and a resulting hospital outbreak were raised. The objectives of the study were to compare the rate of hospital growing MDROs 6 months before and 6 months after the Beirut explosion, to identify emerging microorganisms and to evaluate the change in surgical infection prevention practices.MethodsThis is a retrospective chart review of patients with hospital acquired infections (HAI) admitted to the hospital before and after the Beirut explosion. The study was conducted between February 4, 2020 and January 4, 2021. Excluded patients were those transferred from other hospitals and those with community acquired infections. The primary outcome was to identify the rate of growing MDROs post explosion. The secondary outcomes were identifying antibiotics used for surgical prophylaxis in patients requiring surgeries and patients diagnosed with a HAI. Therefore, patients were divided in three groups. Control group included patients admitted with explosion-related injuries on that same day. Patients admitted and between February 4 and August 4 and diagnosed with HAI were compared to those admitted post August 4 with explosion-related HAI and to patients diagnosed with non-explosion-related HAI between August 4 and January 4, 2021. An estimated rate of 18-22% MDRO was needed to achieve a statistical significance with 80% power and 0.05 α. Pearson Chi square test was used to analyze the primary outcome.ResultsA total of 82 patients with 150 cultures were included in this study. Data showed an increase in the rate of MDRO after the explosion with 37.1% of the cultures taken before the explosion and 53.1% after the explosion (p = 0.05). When comparing the types of HAI in both groups, culture sites were significantly different between pre- and post-explosion patients (p = 0.013). However, both groups had similar types of microbes (p = 0.996) with an increase in candida related infections.ConclusionThese findings confirmed that the Beirut explosion impact on antimicrobial resistance was similar to combat zone incidence, where an increase in MDROs rate such as Escherichia coli (E.Coli) and Stenotrophomonas maltophilia, in addition to the increase in candida related infections.

ANTIFUNGAL ACTIVITY OF SOME PLANTS USED IN YEMENI HERBAL MEDICINE

Capparis cartilaginea Decne.; Vachellia nilotica subspecies Indica (Benth) Kyal &amp; Boatwr.; Fagonia paulayana J. Wagner &amp; Vierh., are medicinal plants used in traditional Yemen medicine for the treatment a variety of infectious and non-infectious diseases. These plants were selected to evaluate their potential antifungal activity. To determine antifungal activity and phytochemicals in the leaves, and total vegetative extracts of three medicinal plants used in traditional Yemeni medicine for the treatment of various disease like rheumatism, piles fever, skin diseases and snake bite. Plant extracts from three species, namely Capparis cartilaginea, Vachellia nilotica subsp. Indica, and Fagonia paulayana, were prepared using ethanol and water. The extracts were tested for their antifungal activity against Candida species isolated from vaginal specimens of women. Phytochemical screening was also performed to identify various constituents in the extracts. The antifungal susceptibility testing was carried out following standard guidelines, and Amphotericin B was used as a reference antifungal agent. The study aimed to evaluate the potential of these plant extracts as natural remedies for Candida-related infections. The study evaluated the antimicrobial activity of plant extracts from Capparis cartilaginea, Vachellia nilotica subsp. Indica, and Fagonia paulayna against Candida fungal isolates from vaginal specimens. Vachellia nilotica subsp. Indica (Ethanol Extract) showed significant inhibitory effects against Candida species, while Capparis cartilaginea and Fagonia paulayna (both Ethanol Extracts) had limited inhibitory activity. Further research is needed to explore the therapeutic potential of Vachellia nilotica subsp. Indica as a natural antifungal agent. Extracts of Vachellia nilotica subsp. Indica demonstrate notable inhibitory effects against Candida species isolated from vaginal samples. This research points to the potential for using extracts of the Vachellia nilotica subsp. Indica plant as a natural remedy for Candida-associated infections.

Candida spp. infection frequency and risk factors in malignant critical care patients

Aims: Candida spp. can cause fatal infections in the person in case of immunosuppression such as malignancy. The aim of our study is to examine the frequency, prognosis and risk factors of candida-related infections in our patients with malignancies followed in our intensive care unit (ICU). Methods: ICU patients with malignancy with fungal infection accepted as the case group and the patients without candida were considered as the control. Demographic characteristics, risk factors and candida risk scores were recorded and compared in both groups. Results: Candida spp. reproduction was observed at a very high rate with 24%. However, there was no difference in mortality between the two groups with and without candida infection. In our study; candida risk score, presence and duration of central venous catheter, antibiotic and steroid use in the last 1 month were found to be the factors determining the risk of candida infection. Conclusion: The contribution of the presence of fungal infection to mortality in our cancer patients does not seem different from others. However, in this patient group, it is difficult to distinguish colonization from invasive fungal infections. At this stage, the use of treatment decisions using risk factors and risk scoring comes to the fore.

Alterations in the Level of Ergosterol in Candida albicans’ Plasma Membrane Correspond with Changes in Virulence and Result in Triggering Diversed Inflammatory Response

Opportunistic pathogen Candida albicans possesses multiple virulence factors which enable colonization and infection of host tissues. Candida-related infections frequently occur in immunocompromised patients, which is related to an insufficient inflammatory response. Furthermore, immunosuppression and multidrug resistance of C. albicans clinical isolates make the treatment of candidiasis a challenge for modern medicine. The most common resistance mechanism of C. albicans to antifungals includes point mutations in the ERG11 gene, which encodes target protein for azoles. We investigated whether the mutations or deletion of the ERG11 gene influence the pathogen-host interactions. We prove that both C. albicans erg11∆/∆ and ERG11K143R/K143R exhibit increased cell surface hydrophobicity. Additionally, C. albicans KS058 has an impaired ability of biofilm and hyphae formation. Analysis of the inflammatory response of human dermal fibroblasts and vaginal epithelial cell lines revealed that altered morphology of C. albicans erg11∆/∆ results in a significantly weaker immune response. C. albicans ERG11K143R/K143R triggered stronger production of pro-inflammatory response. Analysis of genes encoding adhesins confirmed differences in the expression pattern of key adhesins for both erg11∆/∆ and ERG11K143R/K143R strains. Obtained data indicate that alterations in Erg11p consequence in resistance to azoles and affect the key virulence factors and inflammatory response of host cells.

Recent Advances in the Application of Essential Oils as Potential Therapeutic Candidates for Candida-Related Infections

Candidiasis (oral, vulvovaginal, or systemic bloodstream infections) are important human fungal infections associated with a high global prevalence in otherwise healthy adults but are also opportunistic infections in immunocompromised patients. With the recent discovery of the multidrug resistant—and often difficult to treat—Candida auris, as well as the rising costs associated with hospitalisations and the treatment of infections caused by Candida species, there is an urgent need to develop effective therapeutics against these pathogenic yeasts. Essential oils have been documented for many years as treatments for different ailments and are widely known and utilised in alternative and complementary therapies, including treating microbial infections. This review highlights knowledge from research on the effects of medicinal plants, and in particular, essential oils, as potential treatments against different Candida species. Studies have been evaluated that describe the experimental approaches used in investigating the anticandidal effects of essential oils (in vivo and in vitro), the established mode of action of the different compounds against different Candida species, the effect of a combination of essential oils with other compounds as potential therapies, and the evidence from clinical trial studies.

Phytochemical analysis of Cymbopogon flexuosus (lemongrass) oil, its antifungal activity, and role in inhibiting biofilm formation in Candida albicans MTCC854

Background and objectivesCandida albicans is a highly adaptable dimorphic fungal pathogen capable of developing tolerance and resistance to antifungal agents. The treatment of candidiasis becomes more difficult due to the development of biofilms and their morphological variations. Lemongrass oil has been reported for various biological properties and is normally used in various medical applications. In the present study, Cymbopogon flexuosus (lemongrass) oil was analyzed for phytochemicals, studied for its antifungal, anti-biofilm on C. albicans, and cytotoxic effect on HaCaT keratinocytes. MethodsUsing gas chromatography-mass spectrophotometry, the quantitative phytochemical analysis of lemongrass oil was investigated. Antifungal activity and inhibitory activity on biofilm formation of lemongrass oil in C. albicans were evaluated. Cytotoxicity of lemongrass oil on HaCaT keratinocytes was determined by MTT assay. ResultsThe GC–MS analysis revealed that lemongrass oil contains 16 different components. The major components were 4-tert-butylcalix, panaquinquecol 7, and diethyl-, 3, 4-dihydro-1-naphthalenyl ester. The minimum inhibitory concentration was 1.25 µl/ml and the minimum fungicidal concentration was 2.5 µl/ml. Complete inhibition of biofilm formation was observed at 0.5 µl/ml concentration of lemongrass oil and 90.9% inhibition was observed at 0.25 µl/ml concentration. The cell viability of HaCaT keratinocytes was maintained above 51.5% at 1.25 µl/ml concentration, and only a moderate cytotoxic effect was observed at a higher concentration. ConclusionLemongrass oil showed antifungal activity against C. albicans and the lower concentrations inhibited biofilm formation. Cytotoxicity was not observed on HaCaT keratinocytes at lower concentrations. Further studies on the active components of lemongrass oil can be effectively useful in controlling biofilm formation in both medical devices and Candida related infections.

A novel nanotechnological mucoadhesive and fast-dissolving film for vaginal delivery of clotrimazole: design, characterization, and in vitro antifungal action.

Pullulan (PUL) films containing pomegranate seed oil and Eudragit® RS100 nanocapsules loaded with clotrimazole (CTZ-NC-PUL) were developed to treat vulvovaginal candidiasis (VVC). Our findings showed that the nanocapsule average diameter was around 163 ± 4nm, with polydispersity index values of up to 0.1 ± 0.01 and positively charged zeta potential (+ 43.5 ± 0.7mV). The pH was in the acid range (5.14 ± 0.12) and encapsulation efficiency was around 99.6%; CTZ nanoencapsulation promoted higher homogeneity values for the film (91%), and the stability studies displayed no changes in the drug content after 120days for the CTZ-NC-PUL under refrigerated conditions. All formulations were considered non-irritant, and CTZ-NC-PUL promoted a controlled release of the drug (60% in 24h) compared to CTZ-PUL (100% in 8h). The permeation results corroborate the drug release, where higher CTZ amounts were found in the mucosa and receptor medium for CTZ-PUL (21.02 and 4.46μg/cm2). The films were fast dissolving (10min), and CTZ-NC-PUL presented higher mucoadhesive properties; the antifungal activity against Candida albicans was maintained, and the in vitro efficacy of the film was proved. In conclusion, CTZ-NC-PUL formulation was considered promising and suitable for vaginal application against candida-related infections.

Prevalence of biofilms in Candida spp. bloodstream infections: A meta-analysis.

Candida-related infections are nowadays a serious Public Health Problem emerging multidrug-resistant strains. Candida biofilm also leads bloodstream infections to invasive systemic infections. The present meta-analysis aimed to analyze Candida biofilm rate, type, and antifungal resistance among hospitalized patients between 1995 and 2020. Web of Science, Scopus, PubMed, and Google Scholar databases were searched for English papers using the following medical subject heading terms (MESH): "invasive candidiasis"; "bloodstream infections"; "biofilm formation"; "biofilm-related infections"; "mortality"; and "prevalence". The major inclusion criteria included reporting the rate of biofilm formation and the prevalence of biofilm-related to Candida species, including observational studies (more exactly, cohort, retrospective, and case-control studies). Furthermore, data regarding the mortality rate, the geographical location of the study set, and the use of anti-fungal agents in clinical isolates were also extracted from the studies. Independent extraction of articles by 2 authors using predefined data fields, including study quality indicators. A total of 31 studies from publicly available databases met our inclusion criteria. The biofilm formation in the data set varied greatly from 16 to 100% in blood samples. Most of the studies belonged to Europe (17/31) and Asia (9/31). Forest plot showed a pooled rate of biofilm formation of 80.0% (CI: 67-90), with high heterogeneity (Q = 2567.45, I2 = 98.83, τ2 = 0.150) in random effects model (p < 0.001). The funnel plot and Egger's linear regression test failed to find publication bias (p = 0.896). The mortality rate in Candida-related bloodstream infections was 37.9% of which 70.0% were from biofilm-associated infections. Furthermore, Candida isolates were also characterized in low, intermediate, or high biofilm formers through their level of biofilm mass (crystal violet staining or XTT assays) after a 24h growth. When comparing between countries, statistical differences were obtained (p = 0.0074), showing the lower and higher biofilm prevalence values in Italy and Spain, respectively. The prevalence of low, intermediate, and high biofilms were 36.2, 18.9, and 35.0% (p < 0.0001), respectively. C. tropicalis was the prevalent species in high biofilm formation (67.5%) showing statistically significant differences when compared to other Candida species, except for C. krusei and C. glabrata. Finally, the rates of antifungal resistance to fluconazole, voriconazole, and caspofungin related to biofilm were 70.5, 67.9 and 72.8% (p < 0.001), respectively. Early detection of biofilms and a better characterization of Candida spp. bloodstream infections should be considered, which eventually will help preserve public health resources and ultimately diminish mortality among patients.

Antifungal Activity and Mechanism of Action of Different Parts of Myrtus communis Growing in Saudi Arabia against Candida Spp.

Discovering new antifungal drugs from natural products is a key target for the treatment of infections, such as candidiasis and other Candida-related infections. As current therapeutic drugs for the treatment of infections, such as candidiasis and other Candida-related infections, have adverse effects on human health, discovering new antifungal drugs from natural products is urgently needed. The objective of this study was to evaluate the antifungal activity of the methanolic and sodium phosphate buffer extracts derived from various parts of Myrtus communis, a plant that is traditionally used in Saudi Arabia, against Candida albicans (ATCC 10213), Candida glabrata (ATCC 2001), Candida kefyr (ATCC 66028), Candida parapsilosis (ATCC 22019), and Candida tropicalis (ATCC 750). A well diffusion assay was performed to assess the antifungal activity through the measurement of the zone of inhibition. Of the extracts, those extracted with methanol from the roots and leaves displayed strong inhibitory activity against Candida glabrata ( 23.5 ± 0.12 and 20.7 ± 0.22 , respectively), at 50 mg/ml, with 5 mg/ml fluconazole administered as the standard control. The minimal inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values were 12.5 mg/ml and 25 mg/ml for the M. communis root extract and 25 mg/ml and 50 mg/ml for the M. communis leaf extract against Candida glabrata. The results were confirmed by scanning electron microscopy (SEM) imaging of the control and treated strains of Candida glabrata. Based on SEM, these extracts could alter the morphology and cause loss of cell integrity. The effect of M. communis root and leaf extracts on Candida cells was also determined by measuring the absorbance at 260 nm after treatment for 1 h at 37°C. Interestingly, the 260 nm absorbing material was higher in Candida glabrata than in the resistant strain, Candida parapsilosis (ATCC 22019). Based on our findings, the crude methanolic extract of M. communis roots and leaves exhibited good antifungal activity against the Candida glabrata strain. SEM results and estimation of the 260 nm absorbance material proved that the extract might act on the cell wall and cell membrane of Candida cells, further leading to cell death.

Candida Species Distribution of Clinical Specimens in Banda Aceh, Indonesia

Candidiasis has become increasingly widespread in the community alongside with the developing resistance of Candida sp. to some antifungals. A prevalence study in the present research is required to surveil the distribution of Candida-related infections to administrate the appropriate antifungal treatments. The objective of this research was to determine the species distribution of candidiasis with their antifungal susceptibility isolated from clinical specimens at the Zainoel Abidin Hospital (ZAH) Banda Aceh, Indonesia. The clinical specimens were from inpatients and outpatients in the hospital during January to June 2019. The identification of Candida species and antifungal sensitivity assay were conducted by using VITEK® 2 Compact. Of a total of 68 isolates, there were six species of Candida with the highest species prevalence was Candida tropicalis (52.94%). Additionally, the highest prevalence of candidiasis came from urine specimen (54.41%) and mostly from inpatients in the internal medicine unit (54.41%). Candidiasis occurred predominantly in men (58.82%) and during adulthood (55.88%). The antibiogram of Candida sp. shows a high percentage of sensitivity towards some antifungals including fluconazole (100%), voriconazole (100%), caspofungin (100%), micafungin (100%), amphotericin B (99.5%), and flucytosine (100%). From this result, it can be concluded that candidiasis cases in the ZAH Banda Aceh, Indonesia has prevalently occurred with the few antifungal therapies for candidiasis of were still effective empirically and definitively. This is an initial study of Candida prevalence within different clinical samples in Banda Aceh and the study is expected to be a basis for prevention and control of Candida-related infections in the area.

Mechanisms of Pathogenic Candida Species to Evade the Host Complement Attack.

Candida species are common colonizers of the human skin, vagina, and the gut. As human commensals, Candida species do not cause any notable damage in healthy individuals; however, in certain conditions they can initiate a wide range of diseases such as chronic disseminated candidiasis, endocarditis, vaginitis, meningitis, and endophthalmitis. The incidence of Candida caused infections has increased worldwide, with mortality rates exceeding 70% in certain patient populations. C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, and C. krusei are responsible for more than 90% of Candida-related infections. Interestingly, the host immune response against these closely related fungi varies. As part of the innate immune system, complement proteins play a crucial role in host defense, protecting the host by lysing pathogens or by increasing their phagocytosis by phagocytes through opsonization. This review summarizes interactions of host complement proteins with pathogenic Candida species, including C. albicans and non-albicans Candida species such as C. parapsilosis. We will also highlight the various ways of complement activation, describe the antifungal effects of complement cascades and explore the mechanisms adopted by members of pathogenic Candida species for evading complement attack.

Molecular Identification and Virulence Factors Determination in Candida Species Isolated from Egyptian Patients

Candida-related infections are becoming a universal threat to the health of human who undergo immunosuppressive therapy or aggressive medical intervention. Objectives: The aim was to study the distribution of Candida species among winter and summer seasons and to determine the expression of their virulence factors. Methods: A total of 164 Candida isolates were collected from clinical specimens at Mansoura University Hospitals. Candida species were identified by polymerase chain reaction (PCR). Extracellular phospholipase, secretory aspartyl proteinase (SAP) and coagulase enzymes and biofilm formation were determined. SAP 9 and 10 genes were detected by PCR. Results: Non-albicans (NAC) isolates were more dominant than C. albicans isolates (P value C. tropicalis was the most prevalent (59.2%) followed by C. albicans (31.1%), then C. glabrata, C. krusie, unidentified NAC and C. kefyr in 3.7%, 2.4%, 2.4% and 1.2% respectively. Extracellular phospholipase activity was detected in 31.7% of Candida isolates. All C. albicans had phospholipase activity (100%) and one isolate of C. tropicalis was positive while other species were negative. SAPs activities were determined in 61.6% of Candida isolates and were detected in 70.1% and 62.7% among C. tropicalis and C. albicans isolates respectively. SAP9 and SAP 10 genes were detected in 27.7% and 12.9% of Candida isolates showed positive SAPs activity respectively and they were all C. albicans strains. Other species did not harbor either SAP9 or SAP10. Coagulase activity was detected in 80.4% of Candida isolates with higher activity in C. albicans (88.2%), followed by C. tropicalis (81.4%), then other NAC isolates. Biofilm formation was determined in 69.5% of Candida isolates and was more prevalent in C. tropicalis (82.5%) followed by C. albicans (19.6%), C. krusie (100%), unidentified NAC (75%), C. glabrata (33.3%) and C. kefyr (50%). Conclusion: NAC with a preponderance of C. tropicalis was the most common isolated Candida species. Biofilm production, proteinase, phospholipases and coagulase enzymes were observed in both C. albicans and NAC. SAP9 and SAP 10 genes were detected only in C. albicans strains.

The application of UV resonance Raman spectroscopy for the differentiation of clinically relevant Candida species.

Candida-related infections have become a major problem in hospitals. The species identification of yeast is the prerequisite for the initiation of adequate antifungal therapy. In the present study, the connection between inherent UV resonance Raman (RR) spectral profiles of Candida species and taxonomic differences was investigated for the first time. UV RR in combination with statistical modeling was applied to extract taxonomic information from the spectral fingerprints for subsequent differentiation. The identification accuracies of independent batch cultures were determined by applying a leave-one-batch-out cross validation. The quality of differentiation can be divided into three levels. Within a defined taxonomic group comprising the species C. glabrata, C. guilliermondii, and C. haemulonii, the identification accuracy was low. On the next level, the identification results of C. albicans and C. tropicalis were characterized by high sensitivities of 98 and 95% but simultaneously challenged by false-positive predictions due to the misallocation of C. spherica (as C. albicans) and C. viswanathii (as C. tropicalis). The highest level of identification accuracies was reached for the species C. dubliniensis, C. krusei, C. africana, C. novergica, and C. parapsilosis. Reliable identification results were observed with accuracies ranging from 93 up to 100%. The species allocation based on the UV RR spectral profiles could be reproduced by the identification of independent batch cultures. We conclude that the introduced spectroscopic approach is capable of transforming the high-dimensional UV RR data of Candida species into clinically useful decision parameters. Graphical abstract.

Use of cost effective and rapid molecular tools for identification of Candida species, opportunistic pathogens.

Background and Purpose :Candidiasis is a widespread fungal infection caused by different Candida species. Rapid identification of Candida species in clinical laboratory is becoming increasingly important since the identification and discrimination of ethological agents for early treatment. We aimed at molecular identification of commonly Candida species isolated from clinical samples by using both PCR-RFLP assay and amplification of hwp1 gene. Materials and Methods:Clinical samples comprising of vaginal specimens ,cutaneous, sputum, bronchoalveolar lavage(BAL,( and blood cultures were recovered from suspected patients. Candida isolates were initially identified phenotypically and confirmed by molecular approaches based on restriction fragment length polymorphism (PCR-RFLP (with MspI restriction enzyme. Amplification of hwp1 gene was performed for discrimination of C. albicans from C. dubliniensis and C. africana. Results:The most abundant species were C. albicans (n=67; 44.6 %), C. glabrata (n=10; 20 %), C. tropicalis (n=20; 13.3 %), C. krusei (n=12; 8 %), C. parapsilosis (n=11; 7.3 %). Out of 67 C. albicans species, 6 species identified as C. dubliniensis and 4 species identified as C. africana. Conclusion:High frequency of non-albicans Candida species and differences in levels of susceptibility to the antifungal agents are important issues in medicine .Therefore, to manage the Candida-related infections properly, molecular diagnostic methods would be fast, reliable and even cost-effective approaches for identification of Candida species.

Matrine reduces yeast-to-hypha transition and resistance of a fluconazole-resistant strain of Candida albicans.

To evaluate the potential effect of matrine on reducing the growth of hypha and lowering the resistance of a fluconazole-resistant colony of Candida albicans. Candida albicans SC5314 and a fluconazole-resistant C. albicans 215 were used. As for C. albicans SC5314, minimal inhibitory concentration (MIC(80)) and effective concentration (EC(50)) were determined, 1 mg ml(-1) matrine could inhibit nearly 80% of planktonic growth by inverted microscope, 2 mg ml(-1) matrine suppressed 50% of metabolic activity of biofilm by XTT assay, vanishing hypha could be observed on spider agar containing 2 mg ml(-1) matrine, the expressions of three hypha-related genes, namely ALS 3, SUN 41 and PBS 2, were suppressed by 29, 45 and 61% by 2 mg ml(-1) matrine. Also, matrine could lower the resistance of C. albicans 215, in either the free-floating form or the biofilm phenotype. Matrine had favourable antifungal potential and might be able to reverse the fluconazole resistance of clinical isolates at relatively high concentration. The anti-candidal performance of matrine could be tightly associated with yeast-to-hypha transition proved by spider agar test and qRT-PCR. More efforts are needed to find new antifungal agents. Matrine could be a potential candidate to fight against Candida-related infections by regulating yeast-to-hypha transition.

Exopolysaccharide analysis of biofilm‐forming Candida albicans

The major objective of the study was to analyse exopolysaccharide produced by a biofilm forming-clinical strain of Candida albicans. The biofilm-forming ability of C. albicans recovered from infected intrauterine devices (IUDs) was evaluated using XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay. The morphological characteristics of the biofilm were assessed using scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). Biochemical characterization of the exopolysaccharide was carried out by gel permeation chromatography, gas chromatography (GC), Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. Microscopic studies of C. albicans biofilm revealed complex, heterogeneous three-dimensional structure, in which yeast cells and hyphal elements were entrenched within exopolysaccharides matrix. Chromatographic analysis data indicated C. albicans exopolysaccharide (c. 300 kDa) to be made up of four major sugar units. The FTIR spectrum revealed specific absorbance of O-H, C-H, O=C=O, C=O, C-N and C-C ring stretching. (1) H and (13) C NMR data showed the presence of β (1→6) and β (1→3) linkages in the exopolysaccharide chain that were assigned to α-D-glucose and β-D-glucose, α-D-mannose, α-L-rhamnose and N-acetyl glucosamine (β-D-GlcNAc), respectively. Study suggested the production of a water soluble c. 300 kDa exopolysaccharide by C. albicans made up of glucose, mannose, rhamnose and N-acetyl glucosamine subunits. The study could assist in the development of novel therapeutics aimed at disrupting C. albicans biofilms that will translate into improved clearance of Candida-related infections.