Yeast species in the respiratory samples of COVID-19 patients; molecular tracking of Candida auris.

Introduction: Although the existence of Candida species in the respiratory tract is often considered commensal, it is crucial to recognize the significance of Candida colonization in immunocompromised or COVID-19 patients. The emergence of Candida auris as an emerging pathogen further emphasizes the importance of monitoring yeast infection/colonization, particularly in COVID-19 patients. Methods: In this study, respiratory samples mainly from COVID-19 patients, primarily those suspected of having a fungal infection, were cultured on Sabouraud dextrose agar plates and the yeast colonies were identified using a two-step multiplex PCR method. The samples suspected of C. auris underwent specific nested PCR followed by sequence analysis. Results: A total of 199 respiratory samples were collected from 73 women and 126 men, ranging in age from 1.6 to 88 years. Among the patients, 141 had COVID-19, 32 had cancer, 5 were hospitalized in ICU, 2 had chronic obstructive pulmonary disease)COPD(, and others were patients with combination diseases. From these samples, a total of 334 yeast strains were identified. C. albicans (n=132, 39.52%) was the most common species, followed by C. tropicalis (n=67, 20%), C. glabrata (n=56, 16.76%), C. krusei (n=18, 5.4%), C. parapsilosis (n=17, 5.08%), Saccharomyces cerevisiae (n=10, 3%), C. kefyr (n=9, 2.6%), C. dubliniensis (n=7, 2.1%), C. lusitaniae (n=5, 1.5%), C. auris (n=3, 0.9%), C. guilliermondii (n=2, 0.6%), C. rugosa (n=1, 0.3%), C. intermedia (n=1, 0.3%), and Trichosporon spp. (n=1, 0.3%). C. auris was detected in a patient in ICU and two COVID-19 patients. While its presence was confirmed through sequence analysis, our extensive efforts to isolate C. auris were unsuccessful. Conclusion: While C. albicans colonization remains prevalent, our study found no evidence of Candida lung infection. Since the role of Candida colonization in airway secretions remains ambiguous due to limited research, further studies are imperative to shed light on this matter.

The laboratory investigation, management, and infection prevention and control of Candida auris: a narrative review to inform the 2024 national guidance update in England.

The emergent fungal pathogen Candida auris is increasingly recognised as an important cause of healthcare-associated infections globally. It is highly transmissible, adaptable, and persistent, resulting in an organism with significant outbreak potential that risks devastating consequences. Progress in the ability to identify C. auris in clinical specimens is encouraging, but laboratory diagnostic capacity and surveillance systems are lacking in many countries. Intrinsic resistance to commonly used antifungals, combined with the ability to rapidly acquire resistance to therapy, substantially restricts treatment options and novel agents are desperately needed. Despite this, outbreaks can be interrupted, and mortality avoided or minimised, through the application of rigorous infection prevention and control measures with an increasing evidence base. This review provides an update on epidemiology, the impact of the COVID-19 pandemic, risk factors, identification and typing, resistance profiles, treatment, detection of colonisation, and infection prevention and control measures for C. auris. This review has informed a planned 2024 update to the United Kingdom Health Security Agency (UKHSA) guidance on the laboratory investigation, management, and infection prevention and control of Candida auris. A multidisciplinary response is needed to control C. auris transmission in a healthcare setting and should emphasise outbreak preparedness and response, rapid contact tracing and isolation or cohorting of patients and staff, strict hand hygiene and other infection prevention and control measures, dedicated or single-use equipment, appropriate disinfection, and effective communication concerning patient transfers and discharge.

Oral candidiasis in liver transplant patients: species identification and antifungal susceptibility profile.

OBJECTIVE: This study aimed to verify oral candidiasis, identify the causative species, and investigate the antifungal susceptibility of yeasts isolated from liver transplant patients. METHODS: A descriptive analysis of 97 patients who underwent liver transplantation was conducted at a hospital. Two clinical examinations (Collections A and B) of the oral cavity were performed. Oral material was collected from all patients, inoculated in Sabouraud Dextrose Agar, and incubated at 35℃ for 48 hours. Samples were identified by molecular sequencing of the internal trascribed space region of rDNA. RESULTS: An antifungal susceptibility test with fluconazole, amphotericin B, and micafungin was performed using the Clinical and Laboratory Standards Institute yeast broth microdilution method. Among the patients, 15 presented with oral candidiasis: eight in Collection A and seven in Collection B. The primary type of candidiasis was atrophic, followed by pseudomembranous candidiasis. The most prevalent species was Candida albicans (nine), followed by Candida glabrata (three), Candida tropicalis (two), and Candida dubliniensis (one). Regarding susceptibility to fluconazole, of the 15 samples, 11 were susceptible, three were susceptible in a dose-dependent manner, and one was resistant. CONCLUSION: The most commonly identified type of candidiasis was atrophic, with C. albicans and C. glabrata being the most prevalent causative species. One fluconazole-resistant isolate each of C. tropicalis and C. albicans were identified.

Drug-resistant oral candidiasis in patients with HIV infection: a systematic review and meta-analysis.

BACKGROUND: Oral candidiasis (OC) is a prevalent opportunistic infection in patients with human immunodeficiency virus (HIV) infection. The increasing resistance to antifungal agents in HIV-positive individuals suffering from OC raised concerns. Thus, this study aimed to investigate the prevalence of drug-resistant OC in HIV-positive patients. METHODS: Pubmed, Web of Science, Scopus, and Embase databases were systematically searched for eligible articles up to November 30, 2023. Studies reporting resistance to antifungal agents in Candida species isolated from HIV-positive patients with OC were included. Baseline characteristics, clinical features, isolated Candida species, and antifungal resistance were independently extracted by two reviewers. The pooled prevalence with a 95% confidence interval (CI) was calculated using the random effect model or fixed effect model. RESULTS: Out of the 1942 records, 25 studies consisting of 2564 Candida species entered the meta-analysis. The pooled prevalence of resistance to the antifungal agents was as follows: ketoconazole (25.5%, 95% CI: 15.1-35.8%), fluconazole (24.8%, 95% CI: 17.4-32.1%), 5-Flucytosine (22.9%, 95% CI: -13.7-59.6%), itraconazole (20.0%, 95% CI: 10.0-26.0%), voriconazole (20.0%, 95% CI: 1.9-38.0%), miconazole (15.0%, 95% CI: 5.1-26.0%), clotrimazole (13.4%, 95% CI: 2.3-24.5%), nystatin (4.9%, 95% CI: -0.05-10.3%), amphotericin B (2.9%, 95% CI: 0.5-5.3%), and caspofungin (0.1%, 95% CI: -0.3-0.6%). Furthermore, there were high heterogeneities among almost all included studies regarding the resistance to different antifungal agents (I2 > 50.00%, P < 0.01), except for caspofungin (I2 = 0.00%, P = 0.65). CONCLUSIONS: Our research revealed that a significant number of Candida species found in HIV-positive patients with OC were resistant to azoles and 5-fluocytosine. However, most of the isolates were susceptible to nystatin, amphotericin B, and caspofungin. This suggests that initial treatments for OC, such as azoles, may not be effective. In such cases, healthcare providers may need to consider prescribing alternative treatments like polyenes and caspofungin. REGISTRATION: The study protocol was registered in the International Prospective Register of Systematic Reviews as PROSPERO (Number: CRD42024497963).

Comparison of fungemia caused by Candida and non-Candida rare yeasts: a retrospective study from a tertiary care hospital.

Although Candida species are the most common cause of fungemia, non-Candida rare yeasts (NCY) have been increasingly reported worldwide. Although the importance of these yeast infections is recognized, current epidemiological information about these pathogens is limited, and they have variable antifungal susceptibility profiles. In this study, we aimed to evaluate the clinical characteristics for fungemia caused by NCY by comparing with candidemia. The episodes of NCY fungemia between January 2011 and August 2023 were retrospectively evaluated in terms of clinical characteristics, predisposing factor, and outcome. In addition, a candidemia group, including patients in the same period was conducted for comparison. Antifungal susceptibility tests were performed according to the reference method. A total of 85 patients with fungemia episodes were included: 25 with NCY fungemia and 60 with candidemia. Fluconazole had high minimal inhibitory concentration (MIC) values against almost all NCY isolates. The MIC values for voriconazole, posaconazole, and amphotericin B were ≤ 2 µg/ml, and for caspofungin and anidulafungin were ≥ 1 µg/ml against most of isolates. Hematological malignancies, immunosuppressive therapy, neutropenia and prolonged neutropenia, polymicrobial bacteremia/fungemia, preexposure to antifungal drugs, and breakthrough fungemia were associated with NCY fungemia, whereas intensive care unit admission, diabetes mellitus, urinary catheters, and total parenteral nutrition were associated with candidemia. In conclusion, the majority of fungemia due to NCY species was the problem, particularly in hematology units and patients with hematological malignancy. Preexposure to antifungal drugs likely causes a change in the epidemiology of fungemia in favor of non-albicans Candida and/or NCY.

Among all fungemia episodes, hematological malignancies, immunosuppressive therapy, neutropenia, and preexposure to antifungals were risk factors for non-Candida yeast fungemia; diabetes mellitus, urinary catheters, and total parenteral nutrition were risks for candidemia.

Epidemiology, clinical characteristics, outcome and biofilm forming properties in candidaemia: A single-centre retrospective 4-year analysis from Hungary.

BACKGROUND: Candidaemia is a life-threatening disease that is associated with high mortality, especially in intensive care units (ICUs). The number of comprehensive studies dealing with the epidemiologic characteristics of biofilm-related properties is limited. OBJECTIVE: This study evaluated the clinical characteristics of candidaemia, to assess the biofilm-forming properties of isolates, and to identify the risk factors of mortality. PATIENTS AND METHODS: A total of 149 candidaemia episodes from the University of Debrecen, Clinical Centre, between January 2020 and December 2023 were investigated retrospectively. The susceptibility of Candida isolates to fluconazole, amphotericin B, anidulafungin, caspofungin, and micafungin was evaluated and compared to the susceptibility of 1-day-old biofilms. Multivariate logistic regression analysis was applied to identify the independent predictors of 30-day mortality rate. RESULTS: The most common Candida species was Candida albicans (41%), followed by C. parapsilosis (20%), C. glabrata (14%), C. tropicalis (13%), rare Candida species (7%), and C. krusei (5%). Sixty-six percent of Candida isolates were biofilm formers and 44% had high metabolic activity. The 30-day mortality rate was 52%, which was higher in ICUs (65%). The logistic regression analysis revealed several factors significantly influencing mortality including ICU admission (odds ratio [OR] 2.99, 95% confidence interval [CI] 1.17-8.04, p = 0.025), fluconazole treatment (OR 4.12, 95% CI 1.62-11.42, p = .004), and pneumonia (OR 0.261, 95% CI 0.1-0.67, p = .006). CONCLUSIONS: This comprehensive analysis supports the better characterisation of candidaemia in healthcare settings, which ultimately may reduce mortality among patients.

Epidemiological patterns of candidaemia: A comprehensive analysis over a decade.

BACKGROUND: The prevalence of fungal bloodstream infections (BSI), especially candidaemia, has been increasing globally during the last decades. Fungal diagnosis is still challenging due to the slow growth of fungal microorganisms and need for special expertise. Fungal polymicrobial infections further complicate the diagnosis and extend the time required. Epidemiological data are vital to generate effective empirical treatment strategies. OBJECTIVES: The overall aim of this project is to describe the epidemiology of monomicrobial candidaemia and polymicrobial BSI, both with mixed fungaemia and with mixed Candida/bacterial BSIs. METHODS: We conducted a single-centre retrospective epidemiological study that encompasses 950,161 blood cultures during the years 2010 to 2020. The epidemiology of monomicrobial and polymicrobial candidaemia episodes were investigated from the electronic records. RESULTS: We found that 1334 candidaemia episodes were identified belonging to 1144 individual patients during 2010 to 2020. Candida albicans was the most prevalent species detected in candidaemia patients, representing 57.7% of these episodes. Nakaseomyces (Candida) glabrata and Candida parapsilosis complex showed an increasing trend compared to previous studies, whereas Candida albicans demonstrated a decrease. 19.8% of these episodes were polymicrobial and 17% presented with mixed Candida/bacterial BSIs while 2.8% were mixed fungaemia. C. albicans and N. glabrata were the most common combination (51.4%) in mixed fungaemia episodes. Enterococcus and Lactobacillus spp. were the most common bacteria isolated in mixed Candida/bacterial BSIs. CONCLUSIONS: Polymicrobial growth with candidaemia is common, mostly being mixed Candida/bacterial BSIs. C. albicans was detected in more than half of all the candidaemia patients however showed a decreasing trend in time, whereas an increase is noteworthy in C. parapsilosis complex and N. glabrata.

Evaluation of mixed biofilm production by Candida spp. and Staphylococcus aureus strains co-isolated from cystic fibrosis patients in northwest Algeria.

Cystic fibrosis patients' lungs are chronically colonized by multiple microbial species capable of forming biofilms. This study aimed to characterize the polymicrobial biofilm formed by Candida spp. and S. aureus, co-isolated from sputum samples of cystic fibrosis patients regarding microbial density, metabolic activity, and structure. 67 samples from 28 patients were collected with a 96% alteration rate. 34% showed alterations by both Candida spp. and Gram-positive bacteria, predominantly Candida spp. and S. aureus in 77% of cases, accounting for 6 associations. Biofilm biomass was quantified using the crystal violet assay, and metabolic activity was assessed using the MTT reduction assay. Scanning electron microscopy analyzed the C. tropicalis/S. aureus24 biofilm architecture. Candida spp. isolates demonstrated the ability to form mixed biofilms with S. aureus. The C. tropicalis/S. aureus24 association exhibited the highest production of biofilm and metabolic activity, along with the C. albicans17/C. rugosa/S. aureus7 in both single and mixed biofilms.

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.

This is the first prospective cohort study comparing Candida colonization features including species and body sites from the time of admission to the externalization in intensive care unit patients with and without COVID-19. It provides key points that can be referenced for fungal approaches in future disasters.

Candida auris in Greek healthcare facilities: Active surveillance results on first cases and outbreaks from eleven hospitals within Attica region.

BACKGROUND: Candida auris was sporadically detected in Greece until 2019. Thereupon, there has been an increase in isolations among inpatients of healthcare facilities. AIM: We aim to report active surveillance data on MALDI-TOF confirmed Candida auris cases and outbreaks, from November 2019 to September 2021. METHODS: A retrospective study on hospital-based Candida auris data, over a 23-month period was conducted, involving 11 hospitals within Attica region. Antifungal susceptibility testing and genotyping were conducted. Case mortality and fatality rates were calculated and p-values less than 0.05 were considered statistically significant. Infection control measures were enforced and enhanced. RESULTS: Twenty cases with invasive infection and 25 colonized were identified (median age: 72 years), all admitted to hospitals for reasons other than fungal infections. Median hospitalisation time until diagnosis was 26 days. Common risk factors among cases were the presence of indwelling devices (91.1 %), concurrent bacterial infections during hospitalisation (60.0 %), multiple antimicrobial drug treatment courses prior to hospitalisation (57.8 %), and admission in the ICU (44.4 %). Overall mortality rate was 53 %, after a median of 41.5 hospitalisation days. Resistance to fluconazole and amphotericin B was identified in 100 % and 3 % of tested clinical isolates, respectively. All isolates belonged to South Asian clade I. Outbreaks were identified in six hospitals, while remaining hospitals detected sporadic C. auris cases. CONCLUSION: Candida auris has proven its ability to rapidly spread and persist among inpatients and environment of healthcare facilities. Surveillance focused on the presence of risk factors and local epidemiology, and implementation of strict infection control measures remain the most useful interventions.

Rapid identification,fluconazole and micafungin susceptibility testing of Candida species from blood culture by a short incubation method.

This study aimed to develop and validate a rapid method for identification by MALDI-TOF system and determination of the susceptibility to Fluconazole and Micafungin by broth microdilution among Candidaspecies causing bloodstream infections. Subcultures from blood culture bottles were incubated for 5 hours (+/- 1h) and used to perform the tests, so that the turnaround time of rapid identification and susceptibility profile was about 5 and 24 hours, respectively. The rapid identification showed agreement of 92.05 %. Regarding the rapid broth microdilution for Fluconazole and Micafungin, the agreement was 97.06 % (p<0.001) and 100 % (p<0.001), and the Kappa coefficient was 0.91 (p<0.001) and 1.0 (p<0.001), respectively. To conclude, both rapid methods showed to be reproducible, inexpensive, easy to perform and time-saving. Thus, these methodologies could be useful to guide and adjust empirical antifungal therapy.

Is the T2MR Candida Panel a suitable alternative to the SeptiFast for the rapid diagnosis of candidemia in routine clinical practice?

OBJECTIVES: The diagnosis of invasive Candida infection remains challenging because of tests with slow turnaround times or mediocre performance. T2magnetic resonance imaging is a new diagnostic tool. We investigated the diagnostic accuracy of the T2Candida panel (T2) in comparison with blood culture (BC) and the SeptiFast (SF) for the detection of five different Candida species among high-risk intensive care unit patients with suspected candidemia. METHODS: We analysed blood samples collected from patients with suspected candidemia (177 samples from 138 patients) from August 2018 to April 2020. Blood samples were collected and analysed concurrently by BC, SF, and T2Candida. Subsequently, based on clinical and microbiological findings, patient samples were assigned to specific risk categories (proven, probable, and no candidemia). RESULTS: Twenty-two samples from 17 patients were classified as proven candidemia, and 15 samples from 14 patients were classified as probable candidemia. A sensitivity of 68.2% (95% CI, 45-86%) was observed for the BC and the SF, and a sensitivity of 63.6% (95% CI, 41-83%) was observed for the T2 when only cases with proven candidemia were evaluated. For proven and probable candidemia, the sensitivity was 40.5% (95% CI, 23-58%) for BC, 81.1% (95% CI, 65-92%) for SF, and 73.0% (95% CI, 56-86%) for T2. DISCUSSION: The diagnostic performance of SF and T2 was similar. For samples with proven/probable candidemia, SF and T2 had a higher sensitivity compared to BC. Used in conjunction with other diagnostic methods, T2 can replace the no longer available SF for the diagnosis of candidemia, enabling the timely initiation of targeted antifungal therapy.

Lower (1,3)-beta-d-glucan sensitivity and in vitro levels in Candida auris and Candida parapsilosis strains.

OBJECTIVES: The serum (1,3)-beta-d-glucan (BDG) assay gives quicker results and has higher sensitivity than blood cultures, therefore it is advised for early diagnosis of invasive candidemia and/or discontinuation of empirical therapy. Its sensitivity may depend on different factors. The aim of our study was to analyse the in vitro and in vivo BDG levels in clinical isolates of three species of Candida responsible for candidemia. METHODS: C. albicans, C. parapsilosis, and C. auris strains were collected from blood cultures of patients who had a concurrent (-1 to +3 days) serum BDG test (Fungitell assay). Supernatants of all strains were tested in quadruplicate for BDG levels. RESULTS: Twenty-two C. auris, 14 C. albicans, and ten C. parapsilosis strains were included. The median BDG levels in supernatants were 463 pg/mL (interquartile range [IQR] 379-648) for C. auris, 1080 pg/mL (IQR 830-1276) for C. albicans, and 755 pg/mL (IQR 511-930) for C. parapsilosis, with the significant difference among the species (p < 0.0001). Median serum BDG levels (IQR) were significantly lower in case C. auris and C. parapsilosis vs. C. albicans (p < 0.0001), respectively, 50 pg/mL (IQR 15-161) and 57 pg/mL (IQR 18-332), vs. 372 pg/mL (IQR 102-520). Sensitivity of serum BDG was 39% (95% confidence interval [CI], 18-64) in case of C. auris, 30% (95% CI, 8-65) C. parapsilosis and 78% (95% CI, 49-94) C. albicans candidemia. DISCUSSION: In our centre C. auris and C. parapsilosis strains have lower BDG content as compared with C. albicans, with a potential impact on serum BDG performance for the diagnosis of candidemia.

Propyl (E)-3-(furan-2-yl) Acrylate: a synthetic antifungal potential with a regulatory effect on the biosynthesis of ergosterol in Candida Albicans

Abstract The genus Candida represents the main cause of infections of fungal origin. Some species stand out as disease promoters in humans, such as C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis. This study evaluated the antifungal effects of propyl (E)-3-(furan-2-yl) acrylate. The minimum inhibitory concentration of the synthetic compound, amphotericin B and fluconazole alone against four species of Candida ranged from 64 to 512 µg/mL, 1 to 2 µg/mL, and 32 to 256 µg/mL, respectively. The synergistic effect of the test substance was observed when associated with fluconazole against C. glabrata, there was no antagonism between the substances against any of the tested strains. The potential drug promoted morphological changes in C. albicans, decreasing the amount of resistance, virulence, and reproduction structures, such as the formation of pseudohyphae, blastoconidia, and chlamydospores, ensuring the antifungal potential of this substance. It was also possible to identify the fungicidal profile of the test substance through the study of the growth kinetics of C. albicans. Finally, it was observed that the test compound inhibited the ergosterol biosynthesis by yeast

The activity of propolis against pathogenic fungi isolated from human infections

Abstract Propolis is a resinous hive product collected by bees from the buds or other parts of plants. It is known for having various biological properties, including antifungal activity. Among the substances present in propolis, flavonoids and phenolic acids and their esters are responsible for its antifungal properties. This means that propolis is ideal for use as an antifungal agent in alternative medicine to treat a number of both topical and systemic infections caused by Candida species and other yeast-like fungi, dermatophyte and nondermatophyte moulds, without the serious side effects typical of synthetic treatment. It is also active against strains of fungi that are resistant to polyenes and azoles, the classes of drugs most commonly used to treat fungal infections. In this article, we review current knowledge about the activity of propolis from different parts of the world and its components in vitro and in vivo against pathogenic fungi isolated from human infections. The article also indicates the possible mechanism of antifungal activity of propolis and its components.

Biological screening of herbal extracts and essential oil from Plectranthus species: α-amylase and 5-lipoxygenase inhibition and antioxidant and anti-Candida potentials

Abstract The phenolic compound content, the antioxidant and α-amylase inhibition potentials of different extracts of the Plectranthus amboinicus, P. barbatus and P. ornatus were evaluated. We also evaluated the influence of plant growth and harvest time on the chemical composition of the essential oil (EO) of P. amboinicus, its antioxidant and anti-Candida activities and the α-amylase and lipoxygenase inhibitions. The turbo-extract of P. barbatus showed the greatest phenolic compound content and antioxidant activity. No α-amylase inhibition activity was observed in the analyzed extracts, but the turbo-extraction and refluxing extracts possessed high antioxidant activities. Protected cultivation and morning harvest conditions gave the best antioxidant activities, which was associated to the highest carvacrol content. P. amboinicus EO antioxidant activity could contribute to the reduction of oxidative stress in diabetes. Causal Candida strains of diabetic foot ulcers showed sensitivity to P. amboinicus EO. C. albicans and C. dubliniensis were the most sensitive of the selected Candida strains. Turbo-extracts or refluxing of the three species extracts and the EO of P. amboinicus should be considered as a potential candidate for the management the complications of type 2 diabetes.

Metahyphopichia suwanaadthiae sp. nov., an anamorphic yeast species in the order Saccharomycetales and reassignment of Candida silvanorum to the genus Metahyphopichia.

Seven yeast strains, representing a single novel anamorphic species, were isolated in Thailand. They consisted of five strains (DMKU-MRY16T, DMKU-SK18, DMKU-SK25, DMKU-SK30 and DMKU-SK32) obtained from five different mushrooms, and two strains (ST-224 and 11-14.2) derived from insect frass and soil, respectively. The pairwise sequence analysis indicated that all seven strains had identical sequences in the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region. Metahyphopichia silvanorum was the most closely related species, but with 11.9-12.4% nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 13.1-13.3% nucleotide substitutions in the ITS region. The phylogenetic analyses based on the concatenated sequences of the ITS region and the D1/D2 domains of the LSU rRNA gene showed that the seven strains form a well-separated subclade in a clade containing M. silvanorum and Metahyphopichia laotica with high bootstrap support. A phylogenetic analysis of a multilocus dataset including the small subunit (SSU) rRNA gene, the ITS region, the D1/D2 domains of the LSU rRNA gene, translation elongation factor 1-alpha gene, actin gene and the RNA polymerase II subunit 2 gene, confirmed the presence of the monophyletic clade that also includes M. silvanorum and M. laotica, and strongly supported the phylogenetic isolation of the seven strains from its neighbouring species. Therefore, the seven strains were assigned as a single novel species of the genus Metahyphopichia, according to their phylogenetic relationships. The name Metahyphopichia suwanaadthiae sp. nov. is proposed to accommodate the seven strains. The holotype is DMKU-MRY16T (TBRC 11775T=NBRC 114386T=PYCC 8655T). The MycoBank number of the novel species is MB 841280. In addition, Candida silvanorum is reassigned to the genus Metahyphopichia. The MycoBank number of M. silvanorum comb. nov. is MB 841279.

Synthesis of New Thiazole Derivatives Bearing Thiazolidin-4(5H)-One Structure and Evaluation of Their Antimicrobial Activity

The first report about antimicrobial resistance was published in the 1940s. And today, the antimicrobial resistance has become a worldwide problem. Because of this problem, there is a need to develop new drugs. That's why we synthesized some novel thiazolidine-4-one derivatives and evaluated their antimicrobial activity. The final compounds were obtained by reacting 2-[(4,5-diphenylthiazol-2-yl)imino]thiazolidin-4-one with some aryl aldehydes. The synthesized compounds were investigated for their antimicrobial activity against four Candida species, five gram-negative and four gram-positive bacterial species. The lead compounds (4a- h) were obtained with a yield of at least 70%. All compounds showed antimicrobial activity. Compound 4f (MIC: 31.25 µg/ml) exhibited more efficacy than the other compounds against C. glabrata (ATCC 24433). Compound 4b (MIC: 62.5 µg/ml) was the most active compound against all bacterial species, particularly K. pneumoniae (NCTC 9633). Whereas, compound 4c (MIC: <31.25 µg/ml) was observed as the most active compound against E. coli (ATCC 25922). In general, all compounds (4a-4h) showed antimicrobial activity against all fungi and bacterial species. Compounds 4b (2,6-dichlorobenzylidene), 4c (2,6-dihydroxybenzylidene), 4f (1H-pyrrol-2- yl)methylene), 4g (4-triflouromethylbenzylidene) and 4h (2,3,4-trimethoxybenzylidene) were determined as the most active compounds

Antifungal activity of silver nanoparticles and clotrimazole against Candida spp

Abstract The aim of present study was calculate the Minimum inhibitory concentrations (MICs) of silver nanoparticles and clotrimazole for Candida species and their interaction by the adaptation of standarized methods. The MICs values of clotrimazole were 9 E-04-3 E-03 ug/ml, 0.1-0.6 ug/ml, 3 E-03- 0.1 ug/ml and 3 E-03-0.3 ug/ml for Candida albicans susceptible to fluconazole, Candida albicans resistance to fluconazole, Candida krusei and Candida parapsilosis respectively. The MICs values of silver nanoparticles were 26.50- 53 ug/ml; 26.50-106 ug/ml; 106-212 ug/ ml and 26.50- 53 ug/ml for Candida albicans susceptible to fluconazole, Candida albicans resistance to fluconazole, Candida krusei and Candida parapsilosis respectively. Synergism between clotrimazole and silver nanoparticles was measured by checkerboard BMD (broth microdilution) test and shown only for C. albicans susceptible to fluconazole because the fractional inhibitory concentrations (FICs) values were 0.07 - 0.15 ug/ml. Indifference was shown for the other species tested because the FICs values were between 0.5 - 2- 3.06 ug/ml. The results suggest synergistic activity depending on the fungus species analysed, however we recommend the incorporation of others measurement methodologies to confirm our results. As for measurement methodologies of MICs of silver nanoparticles and clotrimazole international normative were respected to guarantee reproducible and comparable results.

Phenotypic Switching and Filamentation in Candida haemulonii, an Emerging Opportunistic Pathogen of Humans.

Phenotypic plasticity is a common strategy adopted by fungal pathogens to adapt to diverse host environments. Candida haemulonii is an emerging multidrug-resistant human pathogen that is closely related to Candida auris. Until recently, it was assumed that C. haemulonii is incapable of phenotypic switching or filamentous growth. In this study, we report the identification of three distinct phenotypes in C. haemulonii: white, pink, and filament. The white and pink phenotypes differ in cellular size, colony morphology, and coloration on phloxine B- or CuSO4-containing agar. Switching between the white and pink cell types is heritable and reversible and is referred to as "the primary switching system." The additional switch phenotype, filament, has been identified and exhibits obviously filamentous morphology when grown on glycerol-containing medium. Several unique characteristics of the filamentous phenotype suggest that switching from or to this phenotype poses as a second yeast-filament switching system. The yeast-filament switch is nonheritable and temperature-dependent. Low temperatures favor the filamentous phenotype, whereas high temperatures promote filament-yeast transition. We further demonstrated that numerous aspects of the distinct cell types differ in numerous biological aspects, including their high temperature response, specific gene expression, CuSO4 tolerance, secreted aspartyl protease (SAP) activity, and virulence. Therefore, transition among the three phenotypes could enable C. haemulonii to rapidly adapt to, survive, and thrive in certain host niches, thereby contributing to its virulence. IMPORTANCE The capacity to switch between distinct cell types, known as phenotypic switching, is a common strategy adopted by Candida species to adapt to diverse environments. Despite considerable studies on phenotypic plasticity of various Candida species, Candida haemulonii is considered to be incapable of phenotypic switching or filamentous growth. Here, we report and describe filamentation and three distinct phenotypes (white, pink, and filament) in C. haemulonii. The three cell types differ in cellular and colony appearance, gene expression profiles, CuSO4 tolerance, and virulence. C. haemulonii cells switch heritably and reversibly between white and pink cell types, which is referred to as the "primary switching system." Switching between pink and filamentous phenotypes is nonheritable and temperature-dependent, representing a second switching system. As in other Candida species, switching among distinct morphological types may provide C. haemulonii with phenotypic plasticity for rapid responses to the changing host environment, and may contribute to its virulence.