Distribution and antifungal susceptibility pattern of Candida species from mainland China: A systematic analysis

Candida guilliermondii fungemia: a 12-year retrospective review of antimicrobial susceptibility patterns at a reference laboratory and tertiary care center

The prevalence of invasive candidiasis caused by non-albicans Candida species is increasing. Candida guilliermondii is an infrequent cause of candidemia but has been associated with decreased susceptibility to triazoles. Clinical data related to the infection with C. guilliermondii are sparse. Our study evaluated the antifungal susceptibility testing (AST) for C. guilliermondii isolates submitted to a reference laboratory over a 12-year period (2012-2023). AST patterns were examined using Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) epidemiological cutoff values (ECVs) and breakpoints. Where isolates were identified from patients treated at our institution, retrospective chart review was performed to describe patient risk factors, treatment approaches, and outcomes associated with C. guilliermondii fungemia. One hundred twelve blood culture isolates of C. guilliermondii were identified, and clinical data were available for 21 fungemic patients. A significant number of isolates (9.8-20.5%) were observed to be non-wild type for various triazoles. All isolates were susceptible to micafungin. A majority (76.2%) of cases of C. guilliermondii fungemia treated at our tertiary care center were hospital-acquired, and two-thirds of patients were immunocompromised at the time of diagnosis. Ten of the 21 patients died within 60 days of fungemia, although mortality was directly or partially attributed to C. guilliermondii fungemia in only four cases (19.0%). Echinocandins may be used for empiric therapy for C. guilliermondii until the results of AST are available. Further research is required to determine appropriate clinical breakpoints for triazoles.

IMPORTANCE

Our study addresses a significant knowledge gap in the clinical management of this non-Candida albicans species. Our retrospective review includes comprehensive AST data for 112 Candida guilliermondii isolates, which is the largest number of isolates reported from the United States to date. Susceptibility data are supplemented by clinical outcomes, where isolates were identified for patients treated at Mayo Clinic. Key findings from our study include the observation that a notable proportion of C. guilliermondii isolates exhibit non-wild-type profiles for various triazoles. Importantly, all isolates remained susceptible to echinocandins, suggesting their efficacy as first-line therapy in the absence of timely susceptibility results. Furthermore, our study highlights the high mortality associated with C. guilliermondii fungemia in immunocompromised patients, emphasizing the urgent need for optimized treatment strategies.

Diversity and Antifungal Susceptibilities of Yeasts from Mangroves in Hong Kong, China-A One Health Aspect

While mangrove ecosystems are rich in biodiversity, they are increasingly impacted by climate change and urban pollutants. The current study provides first insights into the emergence of potentially pathogenic yeasts in Hong Kong's mangroves. Sediment and water samples were collected from ten urban and rural mangroves sites. Initial CHROMagarTM Candida Plus screening, representing the first application of this differential medium for water and soil samples collected from a non-clinical environment, enabled the rapid, preliminary phenotypic identification of yeast isolates from mangroves. Subsequent molecular profiling (ITS and/or 28S nrDNA sequencing) and antifungal drug susceptibility tests were conducted to further elucidate yeast diversity and drug resistance. A diversity of yeasts, including 45 isolates of 18 distinct species across 13 genera/clades, was isolated from sediments and waters from Hong Kong mangroves. Molecular profiling revealed a dominance of the Candida/Lodderomyces clade (44.4%), a group of notorious opportunistic pathogens. The findings also reveal a rich biodiversity of non-Candida/Lodderomyces yeasts in mangroves, including the first reported presence of Apiotrichum domesticum and Crinitomyces flavificans. A potentially novel Yamadazyma species was also discovered. Remarkably, 14.3% of the ubiquitous Candida parapsilosis isolates displayed resistance to multiple antifungal drugs, suggesting that mangroves may be reservoirs of multi-drug resistance. Wildlife, especially migratory birds, may disseminate these hidden threats. With significant knowledge gaps regarding the environmental origins, drug resistance, and public health impacts of pathogenic yeasts, urgent surveillance is needed from a One Health perspective. This study provides an early warning that unrestrained urbanization can unleash resistant pathogens from coastal ecosystems globally. It underscores the necessity for enhanced surveillance studies and interdisciplinary collaboration between clinicians, ornithologists, and environmental microbiologists to effectively monitor and manage this environmental health risk, ensuring the maintenance of 'One Health'.

The first prevalence and antifungal susceptibility profile of Candida infections in Palestine, 2022

BACKGROUND

Candida spp. are the most common cause of opportunistic fungal infections and are associated with a high mortality rate worldwide. In Palestine, the prevalence of Candida spp. infections remains elusive.

METHODS

We performed our study at two hospitals in Palestine (Istishari Arab Hospital, and Najah National University Hospital). All patients diagnosed with candidiasis during the year 2022 have participated in the study. The prevalence of Candida spp., their distribution, and the activity of selected antifungals against Candida pathogens were assessed. In combination with phenotypic properties, Candida isolates were identified and tested for antifungal susceptibility using the colorimetric VITEK-2 Compact system.

RESULTS

Our results showed that the prevalence of Candida spp. among infected samples was 11.6%. A total of eleven different Candida spp. were identified. Among these isolates, C. albicans (46.54%) was the most frequent, followed by C. glabrata (16.14%), C. tropicalis (13.83%), C. parapsilosis (4.82%), C. krusei (3.56%), C. dubliniensis (2.09%), C. ciferrii (1.67%), C. lusitaniae (0.83%), C. guilliermondii (0.62%), C. kefyer (0.41%) and C. spherica (0.20%). Among C. albicans, all isolates were 100% susceptible to fluconazole and micafungin. The susceptibility rates to Amphotericin B and flucytosine were 95% and 99%, respectively. The susceptibility rates of non-albicans Candida spp. (NAC) to fluconazole, voriconazole, amphotericine B, caspofungin, flucytosine and micafungin were 70%, 99%, 97%, ,72%, 92% and 100%, respectively. The incidence of Candida infections was higher in the intensive care unit and surgery department as compared to other hospital departments.

CONCLUSIONS

Four pathogens are responsible for the most invasive infections: C. albicans, C. glabrata, C. tropicalis, and C. parapsilosis. A notable characteristic of this study was the high frequency of NAC species which were often more resistant to antifungal agents. A quick and accurate system like Vitek 2 compact was suggested for the careful species identification of clinical isolates of Candida. We suggest that continued surveillance of species distribution and susceptibility to antifungals will enhance future burden estimates and assist in evaluating preventative measures' effectiveness.

Deciphering microbiome and fungi-bacteria interactions in chronic wound infections using metagenomic sequencing

PURPOSE

Chronic wounds caused by infections impose a considerable global healthcare burden. The microbial features of these infections and possible correlations between bacteria and fungi may influence wound healing. However, metagenomic next-generation sequencing (mNGS) analyses of these features remain sparse. Therefore, we performed mNGS on chronic wound infection samples to investigate features and correlations between the bacteriome and mycobiome in 66 patients (28: chronic wounds; 38: non-chronic wounds).

METHODS

Microbial community characteristics in patients with wound infections, microbiome-systemic inflammation associations, and bacteria-fungi correlations were analyzed.

RESULTS

Infections constituted the primary cause of wounds in this study. Nontuberculous mycobacteria (23%) and Mycobacterium tuberculosis (13%) were the most common pathogens associated with chronic wounds, whereas Staphylococcus aureus (15%) was the most prevalent in non-chronic wound infections. Patients with chronic wound infections had a higher abundance of Pseudomonas aeruginosa than those without chronic wounds. Microbes with a high relative abundance in chronic wound infections were less significantly associated with plasma inflammatory factors than those in non-chronic wound infections. Additionally, a positive correlation between Candida glabrata and P. aeruginosa and an association between Malassezia restricta and anaerobic species were detected in patients with chronic wound infections.

CONCLUSION

Our results further support the hypothesis that P. aeruginosa is a microbial biomarker of chronic wound infection regardless of the causative pathogens. Moreover, we propose a positive correlation between C. glabrata and P. aeruginosa in chronic wound infections, which advances the current understanding of fungi-bacteria correlations in patients with chronic wound infections.

The Increasing Trend of Triazole-Resistant Candida from Vulvovaginal Candidiasis

Purpose

Candida vaginitis is widely prevalent worldwide and is one of the common gynecological disorders. The aim of this study is to analyze the sensitivity of recurrent vulvovaginal (RVVC) candidiasis to antifungal drugs and its relationship with vaginal microbiota.

Patients and Methods

We Isolated and cultured Candida from RVVC patients, mass spectrometry and broth microdilution method were used to identify and determine MIC values of antifungal drugs. Clinical medical records and vaginal microbiota of RVVC patients were also collected.

Results

The main pathogens causing RVVC are predominantly Candida albicans (70.26%), but in recent years, there has been an increasing proportion of Candida glabrata(24.46%). However, only 15.70% of Candida albicans were sensitive to Voriconazole, 35.84% to Fluconazole and 25.60% to Itraconazole. No fluconazole-resistant Candida glabrata was found. Most Candida krusei strains were sensitive to voriconazole (81.80%). More important MIC values of triazoles were increased in Candida species, when exposed to clotrimazole. In addition, we found that the vaginal microecology of candida vaginitis and bacterial vaginitis was significantly different.

Conclusion

Triazoles resistant Candida species have emerged, leading to the failure of empirical anti-infective therapy. At the same time, the vaginal microecology of candida vaginitis and bacterial vaginitis was significantly different. In addition, a new breakpoint for Candida from RVVC needs to be established.

Discovery of petroselinic acid with in vitro and in vivo antifungal activity by targeting fructose-1,6-bisphosphate aldolase

BACKGROUND

The incidence of invasive fungal diseases (IFDs), represented by Candida albicans infection, is increasing year by year. However, clinically available antifungal drugs are very limited and encounter challenges such as limited efficacy, drug resistance, high toxicity, and exorbitant cost. Therefore, there is an urgent need for new antifungal drugs.

PURPOSE

This study aims to find new antifungal compounds from plants, preferably those with good activity and low toxicity, and reveal their antifungal targets.

METHODS

In vitro antifungal activities of compounds were investigated using broth microdilution method, spot assay, hyphal growth assay and biofilm formation assay. Synergistic effects were assessed using broth microdilution checkerboard technique. In vivo antifungal activities were evaluated using Galleria mellonella and murine candidiasis models. Cytotoxicity of compounds was investigated using Cell Counting Kit-8 (CCK-8). Discovery and validation of antifungal targets of compounds were conducted by using monoallelic knockout library of C. albicans, haploinsufficiency profiling (HIP), thermal shift assay (TSA), enzyme inhibitory effect assay, molecular docking, and in vitro and in vivo antifungal studies.

RESULTS

814 plant products were screened, among which petroselinic acid (PeAc) was found as an antifungal molecule. As a rare fatty acid isolated from coriander (Coriandrum sativum), carrot (Daucus carota) and other plants of the Apiaceae family, PeAc had not previously been found to have antifungal effects. In this study, PeAc was revealed to inhibit the growth of various pathogenic fungi, exhibited synergistic effects with fluconazole (FLC), inhibited the formation of C. albicans hyphae and biofilms, and showed antifungal effects in vivo. PeAc was less toxic to mammalian cells. Fructose-1,6-bisphosphate aldolase (Fba1p) was identified as a target of PeAc by using HIP, TSA, enzyme inhibitory effect assay and molecular docking methods. PeAc exerted antifungal effects more effectively on fba1Δ/FBA1 than wild-type (WT) strain both in vitro and in vivo.

CONCLUSIONS

PeAc is an effective and low toxic antifungal compound. The target of PeAc is Fba1p. Fba1p is a promising target for antifungal drug development.

Hand Carriage of Yeast in Student of Medicine, Nursing, and Medical Laboratory Science: Impact of Infection Control Measures

We studied yeast hand carriage of 260 healthcare students. We isolated yeasts in 27 students (10.4%), without differences between medicine, nursing, and medical laboratory science programs and gender. A significant lower prevalence of carriage was shown in the clinical cycle (2.7%) compared to the basic cycle (13.5%) (p = 0.022) and the preclinical cycle (13.5%) (p = 0.014). Increased handwashing frequency and the use of alcohol gel and antiseptic soap decreased yeast carriage. Students who applied moisturizing hand cream two or more times a day had a lower frequency of yeast carriage (3.4%) than those who did not use it or used it once a day (16.5%), showing a significant difference (p = 0.016). The most prevalent species was C. parapsilosis sensu stricto (81.5%), followed by Meyerozyma guilliermondii (C. guillermondii) (7.4%), Trichosporon mucoides (7.4%), and R. mucilagenosa (3.7%). One case showed mixed carriage of C. parapsilosis and C. albicans. All strains were sensitive to voriconazole, caspofungin, and anidulafungin. This study shows hand carriage of yeast in health students, mainly by C. parapsilosis, and the frequency of infection control measures and moisturizing hand cream is associated with colonization control.

Cluster analysis allowed to identify antifungal drugs that retain efficacy against Candida albicans isolated from patients with inflammatory diseases of the soft tissues of the maxillofacial area

Physicians are increasingly prescribing antifungal drugs empirically to treat hospital-acquired infections quickly. This makes it obvious that fungal infections require more attention and systematic monitoring of resistance among them. The aim of the study was to identify antifungal drugs that retain their efficacy against C. albicans isolates. There were 17 clinical isolates of Candida albicans obtained from patients and tested for susceptibility to antifungal drugs using the standard double dilution method. Amphotericin B, fluconazole, itraconazole, micafungin, and posaconazole were used in the study. To determine the groups of antimycotics to which the studied microorganisms retain sensitivity, a hierarchical cluster analysis was performed using the Ward's method. The tested representatives of the genus Candida showed the lowest sensitivity to fluconazole. The efficacy of amphotericin B and itraconazole was almost at the same level. In turn, micafungin and posaconazole showed the best results against C. albicans isolates. Ward's cluster analysis combined the results of C. albicans susceptibility to fluconazole, micafungin and itraconazole by the highest mathematical similarity. Amphotericin B and posaconazole were combined into one cluster due to their better efficacy against Candida albicans isolates.

Candidaemia: A 9-Year Retrospective Analysis of Epidemiology and Antimicrobial Susceptibility in Tertiary Care Hospitals in Western China

Purpose

This investigation endeavors to scrutinize the resistance profiles to antifungal agents, alongside the clinical distribution of Candida isolates that yielded positive results in blood cultures at Suining Central Hospital spanning the years 2015 to 2023. The objective is to provide crucial epidemiological insights that may aid in early clinical intervention and judicious deployment of antifungal therapies.

Methods

This retrospective analysis analyses data on 182 different Candida strains with positive clinical blood cultures obtained from the Microbiology Laboratory of Suining Central Hospital over a period of nine consecutive years. The study involved identification of Candida species and assessment of resistance patterns to fungal drugs.

Results

Our analysis revealed that the median age of patients diagnosed with Candidaemia from the 182 strains was 62 years, with a distribution of 63.7% females and 36.3% males. Within the cohort of 182 Candida strains, Candida albicans constituted 32.4%, while non-albicans Candida species comprised 67.6% of the cases. Specifically, Candida tropicalis represented 37.4%, Candida glabrata 12.1%, Candida parapsilosis 11.0%,Candida guilliermondii 3.8%, and both Candida krusei and Candida Dublin accounted for 1.6% each. These Candida species were predominantly identified in intensive care units (ICU), hematology, gastroenterology, neurology centers, and endocrine metabolism units.

Conclusion

The findings of this investigation suggest a shift in the prevalence of non-Candida albicans species, notably C. tropicalis, as the predominant cause of Candidaemia at Suining Central Hospital, surpassing C. albicans. Although instances of antifungal resistance are infrequent, there has been a notable rise in resistance to azoles. This study provides important insights into the local epidemiology, which will be essential for informing the selection of empirical antifungal therapy and contributing to the global surveillance of antifungal resistance.

Vulvovaginal candidiasis, an increasing burden to women in the tropical regions attending Bharatpur Hospital, Chitwan

Vulvovaginal candidiasis is a yeast infection commonly caused by the overgrowth of Candida species in and around the vulva and vagina. Abnormal vaginal discharge, itching and irritation, swelling and redness of the vaginal area, pain during sexual intercourse, and dyspareunia are important clinical findings of the infection. Currently, the infection is one of the growing burdens to married women. Moreover, the infection with antifungal-resistant Candida species adds challenges to managing the disease. Hence, this study was conducted to identify the different Candida species causing vulvovaginal candidiasis and to determine its susceptibility pattern against different antifungal drugs. A hospital-based cross-sectional and quantitative study was conducted for the period of six months from September 2022 to March 2023 among symptomatic married women in the Gynecology and Obstetrics Department of Bharatpur Hospital, Chitwan. A total of 300 symptomatic cases were enrolled in the study. Candida species were isolated from vaginal swabs following standard microbiological procedures and antifungal susceptibility testing was performed with different antifungal agents. The total prevalence of vulvovaginal candidiasis was found to be 37.3 % (112/300). Among different isolates, Candida albicans was found to be the most predominant (52.6 %), followed by Candida glabrata (29.3 %) among non-albicans. Women from the age group 25-35 years were found to be more infected (47.3 %) and the relationship between contraceptive use and vulvovaginal candidiasis was found to be statistically significant (p < 0.05). Candida species showed higher susceptibility toward Amphotericin-B (68.1 %), followed by fluconazole (Diflucan), and Clotrimazole (50.9 %). Whereas the least susceptibility was observed to Voriconazole (27.6 %) and Itraconazole (35.30 %). Candida albicans was comparatively more susceptible to different antifungal drugs than non-albicans species. Candida parapsilosis was only susceptible to Amphotericin-B and the increasing incidence of vaginal candidiasis due to non-albicans Candida indicates the need for routine speciation of Candida.

An Unusual High Prevalence of Cryptococcus (Naganishia) diffluens Colonization in Neonates Hospitalized in a Referral Neonatal Intensive Care Unit

BACKGROUND

Although the Candida species continue to be the most frequent colonizer of neonatal skin, a clear increase of colonization due to rare yeast-like fungi has been reported. In this study, we report an unusual high prevalence of Cryptococcus diffluens colonization in neonates admitted to the neonatal intensive care unit (NICU) over a 1-month period.

METHODS

From January 2020 to June 2021, the study included all neonates who were admitted to the NICU of Bu Ali Sina Hospital at least 28 days old. Skin swabs from different anatomical areas were collected. Sampling was done 3 times/week. Each sample was inoculated into Sabouraud Dextrose Agar containing chloramphenicol and CHROMagar Candida, separately. The plates were incubated at 30 °C and 35 °C, respectively. Identification of the isolates was molecularly confirmed. In vitro antifungal susceptibility testing of the isolates was performed against different antifungal agents using the Clinical Laboratory Standards Institute protocol.

RESULTS

Among 1026 samples collected from 78 neonates, 213 yeast isolates were recovered, of which the Candida species were the most common (77.5%), followed by C. diffluens (16.9%). During the study, 55 isolated yeasts were collected from December 26, 2020, to January 26, 2021, of which 65.5% were C. diffluens , while Candida spp. constituted 100% and 98.3% of the isolates before and after this period, respectively. The most frequent sources of C. diffluens were genital regions (27.8%). Of 36 C. diffluens isolates, 13.9%, 22.2%, 52.8%, and 83.3% were non-wild type to fluconazole, amphotericin B, itraconazole and 5-flucytosine, respectively.

CONCLUSIONS

We reported for the first time an unusual high prevalence of C. diffluens colonization in neonates hospitalized in NICU. Our findings also showed the high minimum inhibitory concentration of amphotericin B and 5-flucytosine against C. diffluens .

A Case of Spontaneous Recovery in an Infant with Nail Candidiasis Probably Related to Nail Trauma During Vaginal Delivery

Onychomycosis in infants is a rare fungal infection. The condition is frequently linked to congenital or secondary immunodeficiency, as well as exposure to contaminated environments. In this report, we present a case of infant onychomycosis, likely infected during birth delivery from the mother with vaginal candidiasis. However, both the infant and the mother recovered spontaneously without any treatment over several months.

Emerging trends of invasive yeast infections and azole resistance in Beijing intensive care units

BACKGROUND

Invasive fungal infections pose a substantial threat to patients in healthcare settings globally. Recent changes in the prevalence of fungal species and challenges in conducting reference antifungal susceptibility testing emphasize the importance of monitoring fungi and their antifungal resistance.

METHODS

A two-phase surveillance project was conducted in Beijing, China, involving 37 centres across 12 districts, from January 2012 to December 2013 and from January 2016 to December 2017.

FINDINGS

We found that the proportion of Candida albicans in intensive care units (ICUs) during 2016-2017 exhibited a significant decline compared with the 2012-2013 period, although it remained the most predominant pathogen. In contrast, the prevalence of Nakaseomyces glabratus (formerly Candida glabrata) and Candida tropicalis notably increased during the two-phase surveillance. The high prevalence of C. tropicalis and its resistance to azole drugs posed a serious threat to patients in ICUs. The pathogens causing invasive fungal infections in Beijing were relatively sensitive to echinocandins. While C. albicans continued to exhibit susceptibility to azoles, the resistance and growth rates of C. tropicalis towards azoles were particularly prominent. Concerns were raised due to the emergence of multiple, short-term isolates of Clavispora lusitaniae and Candida parapsilosis complex in neonatal ICUs, given their similarity in antifungal susceptibilities. Such occurrences point towards the potential for transmission and persisting presence of these pathogens within the ICU environment.

CONCLUSIONS

Our study complements existing data on the epidemiology of invasive fungal infections. It is imperative to exercise cautious medication management for ICU patients in Beijing, paying particular attention to azole resistance in C. tropicalis.

Comparative study of antifungal susceptibility testing methods for clinical Candida albicans isolates

PURPOSE

Candida albicans is the second most common cause of candidemia in Malaysia. The Clinical and Laboratory Standards Institute (CLSI) broth microdilution method is the gold standard for determining its minimum inhibitory concentration (MIC); however, it is laborious and time-consuming. This study was conducted to evaluate the usefulness of alternative methods, namely Sensititre YeastOne (SYO), VITEK 2 system, and E-test for determining the MIC of clinical C. albicans isolates.

MATERIALS AND METHODS

The susceptibilities of 95 C. albicans isolates were compared between SYO, VITEK 2 system, and E-test with CLSI broth microdilution method. The categorical agreement (CA), essential agreement (EA), very major errors (VME), major errors (ME) and minor errors (MiE) were calculated.

RESULTS

Our finding showed the CA varied for SYO from 96.8% to 100%, while the EA ranged from 91.6% to 100%. The SYO method showed 1.1% of VME and ME, and up to 3.2% of MiE. Next, the CA and EA ranges for the VITEK 2 system were 97.8%-100% and 23.2%-100%, respectively. In the VITEK 2 technique, 1.1% of VME were found. For the E-test, the CA varied from 83.2% to 100% while the EA ranged from 64.2% to 98.9%. The E-test method showed 1.1% of VME and up to 16.8% of MiE.

CONCLUSIONS

In conclusion, SYO and VITEK 2 (except flucytosine) could be potential alternatives to the CLSI broth microdilution method in determining the MIC of C. albicans.

Clinical and epidemiological aspects of Candida yeast infections and rational use of antifungals

Aim: The objective of this study was to evaluate the clinical and epidemiological aspects of Candida infections. Methods: The study relied on the analysis of electronic medical records. Results: Among 183 patients with positive fungal infections, 57 were from the community and 126 from hospitals. Females predominated in both groups (82.4% in the community, 54.7% in hospitals). Non-albicans Candida spp. accounted for 62.8% of cases. Antifungal therapy was prescribed for 67 patients, with a 55.6% mortality rate. Conclusion: The increasing prevalence of non-albicans Candida species highlights the need for better candidiasis monitoring and control, especially concerning antifungal use amidst rising antimicrobial resistance, particularly in empirical therapy scenarios.

Taxonomy of Candida parapsilosis complex isolated from neonates and the role of Hsp90 inhibitors to enhanced the antifungal activity of micafungin

Species from Candida parapsilosis complex are frequently found in neonatal candidemia. The antifungal agents to treat this infection are limited and the occurrence of low in vitro susceptibility to echinocandins such as micafungin has been observed. In this context, the chaperone Hsp90 could be a target to reduce resistance. Thus, the objective of this research was to identify isolates from the C. parapsilosis complex and verify the action of Hsp90 inhibitors associated with micafungin. The fungal identification was based on genetic sequencing and mass spectrometry. Minimal inhibitory concentrations were determined by broth microdilution method according to Clinical Laboratory and Standards Institute. The evaluation of the interaction between micafungin with Hsp90 inhibitors was realized using the checkerboard methodology. According to the polyphasic taxonomy, C. parapsilosis sensu stricto was the most frequently identified, followed by C. orthopsilosis and C. metapsilosis, and one isolate of Lodderomyces elongisporus was identified by genetic sequencing. The Hsp90 inhibitor geladanamycin associated with micafungin showed a synergic effect in 31.25% of the isolates, a better result was observed with radicicol, which shows synergic effect in 56.25% tested yeasts. The results obtained demonstrate that blocking Hsp90 could be effective to reduce antifungal resistance to echinocandins.

Interleukin inhibitors and the associated risk of candidiasis

Interleukins (ILs) are vital in regulating the immune system, enabling to combat fungal diseases like candidiasis effectively. Their inhibition may cause enhanced susceptibility to infection. IL inhibitors have been employed to control autoimmune diseases and inhibitors of IL-17 and IL-23, for example, have been associated with an elevated risk of Candida infection. Thus, applying IL inhibitors might impact an individual's susceptibility to Candida infections. Variations in the severity of Candida infections have been observed between individuals with different IL inhibitors, necessitating careful consideration of their specific risk profiles. IL-1 inhibitors (anakinra, canakinumab, and rilonacept), IL-2 inhibitors (daclizumab, and basiliximab), and IL-4 inhibitors (dupilumab) have rarely been associated with Candida infection. In contrast, tocilizumab, an inhibitor of IL-6, has demonstrated an elevated risk in the context of coronavirus disease 2019 (COVID-19) treatment, as evidenced by a 6.9% prevalence of candidemia among patients using the drug. Furthermore, the incidence of Candida infections appeared to be higher in patients exposed to IL-17 inhibitors than in those exposed to IL-23 inhibitors. Therefore, healthcare practitioners must maintain awareness of the risk of candidiasis associated with using of IL inhibitors before prescribing them. Future prospective studies need to exhaustively investigate candidiasis and its associated risk factors in patients receiving IL inhibitors. Implementing enduring surveillance methods is crucial to ensure IL inhibitors safe and efficient utilization of in clinical settings.

Epidemiology and antifungal susceptibility of fungal infections from 2018 to 2021 in Shandong, eastern China: A report from the SPARSS program

PURPOSE

We analyzed the pathogenic fungal epidemiology and antifungal susceptibility from 2018 to 2021 in Shandong Province, China, to provide the basis for empiric antifungal therapy.

METHODS

Fungal isolates were collected from 54 hospitals in Shandong province from 2018 to 2021 through the Shandong Province Pediatric bacterial & fungal Antimicrobial Resistance Surveillance System (SPARSS), WHONET v5.6 and SPSS software v20.0 were used for statistical analysis.

RESULTS

A total of 15,348 strains of fungi were collected, with Candida accounting for 78.25 %, followed by Aspergillus at 15.45 %, and other species at 6.27 %. Candida albicans was the predominant Candida species, but more than half of the Candida isolates were non-albicans species, with C. tropicalis being the most dominant (22.74 %), followed by C. glabrata (17.50 %) and C. parapsilosis (11.02 %). The composition of fungi varied significantly among different age groups. Children had a higher proportion of C. albicans (47.30 %) compared to non-children (32.06 %). The non-wild-type phenotype rate of Candida for Amphotericin B was less than 3 %, while Cryptococcus neoformans was 16.67 %. In addition, less than 6 % of C. albicans and C. parapsilosis were resistant to fluconazole and voriconazole, and 96.30 % of C. glabrata were SDD to fluconazole. We also found that 80.56 % of C. glabrata and 83.70 % of C. krusei were voriconazole WT/susceptibility phenotype. However, the susceptibility rates of C. tropicalis to fluconazole/voriconazole decreased from 70.40 %/46.40 % in 2018 to 62.30 %/35.20 % in 2021. The comprehensive susceptibility rate to fluconazole of C. albicans, C. tropicalis, C. parapsilosis and C. glabrata isolated from the blood has decreased from 69.36 % to 56.62 %.

CONCLUSIONS

The study reveals that the composition and antifungal susceptibility of pathogenic fungi in Shandong Province differ from other regions. Moreover, the resistance to azoles is more severe, especially in C. tropicalis. These findings indicate the need for region-specific antifungal treatment strategies to combat fungal infections effectively.

Whole genome analysis of echinocandin non-susceptible Candida Glabrata clinical isolates: a multi-center study in China

BACKGROUND

Candida glabrata is an important cause of invasive candidiasis. Echinocandins are the first-line treatment of invasive candidiasis caused by C. glabrata. The epidemiological echinocandin sensitivity requires long-term surveillance and the understanding about whole genome characteristics of echinocandin non-susceptible isolates was limited.

RESULTS

The present study investigated the echinocandin susceptibility of 1650 C. glabrata clinical isolates in China from August 2014 to July 2019. The in vitro activity of micafungin was significantly better than those of caspofungin and anidulafungin (P < 0.001), assessed by MIC50/90 values. Whole genome sequencing was conducted on non-susceptible isolates and geography-matched susceptible isolates. Thirteen isolates (0.79%) were resistant to at least one echinocandin. Six isolates (0.36%) were solely intermediate to caspofungin. Common evolutionary analysis of echinocandin-resistant and echinocandin-intermediate isolates revealed genes related with reduced caspofungin sensitivity, including previously identified sphinganine hydroxylase encoding gene SUR2. Genome-wide association study identified SNPs at subtelometric regions that were associated with echinocandin non-susceptibility. In-host evolution of echinocandin resistance of serial isolates revealed an enrichment for non-synonymous mutations in adhesins genes and loss of subtelometric regions containing adhesin genes.

CONCLUSIONS

The echinocandins are highly active against C. glabrata in China with a resistant rate of 0.79%. Echinocandin non-susceptible isolates carried common evolved genes which are related with reduced caspofungin sensitivity. In-host evolution of C. glabrata accompanied intensive changing of adhesins profile.

Abrogation of efflux pump activity, biofilm formation, and immune escape by candidacidal geraniol in emerging superbug, Candida auris

During the last decade, Candida auris emerged as a threatening human fungal pathogen that notably caused outbreaks around the globe with high mortality. Considering C. auris species as newly discovered fungi, the evolutionary features remain elusive. The antifungal resistance which is a norm in C. auris underlines the need for innovative therapeutic options. ATP Binding Cassette (ABC) superfamily efflux pumps overexpression and biofilms are known to be major contributors to multidrug resistance (MDR) in C. auris. Therefore, herein, we investigated the antifungal potential of geraniol (Ger) as a promising natural compound in the fight against MDR C. auris. Our experiments proved that Ger was fungicidal in nature and impaired rhodamine 6G (R6G) efflux, confirming the specific effect on ABC transporters. Kinetic studies unravelled the competitive mode of inhibition by Ger for R6G efflux since the apparent Km increased with no change in Vmax value. Mechanistic insights also revealed that Ger depleted ergosterol content in C. auris. Furthermore, Ger led to inhibition in biofilm formation as evident from crystal violet staining, biofilm metabolic and biomass measurements. Additionally, enhanced survival of Caenorhabditis elegans model after C. auris infection demonstrated the in vivo efficacy of Ger. Lastly, the in vivo efficacy was confirmed from a THP-1 cell line model which depicted enhanced macrophage-mediated killing in the presence of Ger. Modulation of C. auris efflux pump activity and biofilm formation by Ger represents a promising approach to combat MDR. Together, this study demonstrated the potential therapeutic insights of Ger as a promising addition to the antifungal armamentarium required to treat emerging and resistant C. auris.

Epidemiology and antifungal susceptibilities of clinically isolated Aspergillus species in South China

Aspergillosis is a rising concern worldwide; however, its prevalence is not well documented in China. This retrospective study determined Aspergillus's epidemiology and antifungal susceptibilities at Meizhou People's Hospital, South China. From 2017 to 2022, the demographic, clinical, and laboratory data about aspergillosis were collected from the hospital's records and analysed using descriptive statistics, chi-square test, and ANOVA. Of 474 aspergillosis cases, A. fumigatus (75.32%) was the most common, followed by A. niger (9.92%), A. flavus (8.86%), and A. terreus (5.91%). A 5.94-fold increase in aspergillosis occurred during the study duration, with the highest cases reported from the intensive care unit (52.74%) - chronic pulmonary aspergillosis (79.1%) and isolated from sputum (62.93%). Only 38 (8.02%) patients used immunosuppressant drugs, while gastroenteritis (5.7%), haematologic malignancy (4.22%), and cardiovascular disease (4.22%) were the most prevalent underlying illnesses. In A. fumigatus, the wild-type (WT) isolates against amphotericin B (99.1%) were higher than triazoles (97-98%), whereas, in non-fumigatus Aspergillus species, the triazole (95-100%) WT proportion was greater than amphotericin B (91-95%). Additionally, there were significantly fewer WT A. fumigatus isolates for itraconazole and posaconazole in outpatients than inpatients. These findings may aid in better understanding and management of aspergillosis in the region.

Pseudolaric Acid A: A Promising Antifungal Agent Against Prevalent Non-albicans Candida Species

Purpose

The non-albicans Candida (NAC) species have recently gained great importance worldwide due to the increasing proportion in candida causing bloodstream infections. This investigation aimed to explore the efficacy of Pseudolaric acid A (PAA, a diterpenoid derived from Pseudolarix kaempferi) and its synergistic effect with fluconazole (FLC) against NAC species, including C. tropicalis, C. parapsilosis complex, and C. glabrata.

Methods

The microdilution checkerboard assay and time-killing curves were performed to detect the antifungal efficiency. To examine the integrity of cell walls and membranes, calcofluor white stain and propidium iodide stain were used. The changes of intracellular ultrastructure in Candida cells after treatment were observed using transmission electron microscopy. Changes in cell viability with the autophagy inhibitor 3-MA were assessed by the XTT method.

Results

It was revealed that PAA alone is effective on C. tropicalis, C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis (MIC 8-128 µg/mL). Strong synergism against FLC-resistant C. tropicalis was observed (FICI 0.07-0.281), when PAA and FLC were combined. PAA had dose-dependently detrimental effects on C. tropicalis cell membranes. Moreover, increased vacuoles and autophagosome formation were found in C. tropicalis exposed to PAA. And the inhibitory effect of PAA against C. tropicalis can be relieved by autophagy inhibitor 3-MA in a certain concentration range. Ultrastructural alterations of C. tropicalis were more pronounced under the combination of PAA and FLC, including separation of the cell membrane from the cell wall, increased number of vacuoles, and degradation of organelles.

Conclusion

These observations indicated that PAA and its combination with FLC could be a promising therapeutic candidate for treating infections caused by NAC species.

The role of fungi in the diagnosis of colorectal cancer

Colorectal cancer (CRC) is a prevalent tumour with high morbidity rates worldwide, and its incidence among younger populations is rising. Early diagnosis of CRC can help control the associated mortality. Fungi are common microorganisms in nature. Recent studies have shown that fungi may have a similar association with tumours as bacteria do. As an increasing number of tumour-associated fungi are discovered, this provides new ideas for the diagnosis and prognosis of tumours. The relationship between fungi and colorectal tumours has also been recently identified by scientists. Therefore, this paper describes the limitations and prospects of the application of fungi in diagnosing CRC and predicting CRC prognosis.

Six-Year Retrospective Analysis of Epidemiology, Risk Factors, and Antifungal Susceptibilities of Candidiasis from a Tertiary Care Hospital in South China

Candidiasis is a life-threatening disease that increases mortality in critically ill patients. However, such epidemiological data are still lacking in underdeveloped regions of China. A retrospective analysis (2016 to 2021) was conducted in Meizhou People's Hospital, China to study the burden of candidiasis, particularly candidemia, and antifungal susceptibilities of the species among hospitalized patients. Of the 7,864 candidiasis cases, 461 (5.86%) were candidemia cases. Candida albicans (64.25%) was the most identified species, followed by C. tropicalis (12.61%), C. glabrata (10.79%), and C. parapsilosis (9.79%). In non-C. albicans (NCA) candidemia cases, the number of C. glabrata cases was higher (102/461, 22.37%) than C. tropicalis (64/461, 14.04%). Gastrointestinal pathology, respiratory dysfunctions, septic shock, and malignancies were common underlying comorbidities, respectively. A central venous catheter was an independent risk factor for both C. albicans and NCA candidemia. The mortality rate was not statistically significant for either C. albicans or NCA. Amphotericin B and 5-flucytosine were highly effective (98 to 100%), while azoles were least effective (67.74 to 95.66%). Candidemia cases caused by C. tropicalis and C. glabrata had significantly lower azole susceptibility than non-candidemia-causing isolates. This study provides valuable information for prescribers to choose the right empirical therapy, for researchers to explore different resistance mechanisms, and for health care managers to control candidiasis better. IMPORTANCE This study provides important information on the burden of candidiasis, particularly candidemia, and the antifungal susceptibility of Candida species among hospitalized patients in an underdeveloped region of China. First, the finding that azoles were least effective against Candida species causing candidemia is particularly noteworthy, as it suggests the possibility of resistance to this class of antifungal agents. This information can guide the choice of empirical therapy and help in the selection of appropriate antifungal agents for the treatment of candidemia, thereby reducing the risk of resistance development. Second, the study provides important information for researchers to explore different resistance mechanisms in Candida species. Finally, the study has important implications for health care managers in controlling the spread of candidiasis. The high prevalence of candidemia cases in the study highlights the need for appropriate infection control measures to prevent the spread of the disease.

Fungal Spectrum and Susceptibility Against Nine Antifungal Agents in 525 Deep Fungal Infected Cases

Background

Deep fungal infection has become an important cause of infection and death in hospitalized patients, and this has worsened with increasing antifungal drug resistance.

Objective

A 3-year retrospective study was conducted to investigate the clinical characteristics, pathogen spectrum, and drug resistance of deep fungal infection in a regional hospital of Guangzhou, China.

Methods

Non-duplicate fungi isolates recovered from blood and other sterile body fluids of in-patients of the clinical department were identified using biochemical tests of pure culture with the API20C AUX and CHROMagar medium. Antifungal susceptibilities were determined by Sensititre YeastOne^® panel trays.

Results

In this study, 525 patients (283 female, 242 male) with deep fungal infection were included, half of them were elderly patients (≥60 years) (54.67%, n=286). A total of 605 non-repetitive fungi were finally isolated from sterile samples, of which urine specimens accounted for 66.12% (n=400). Surgery, ICU, and internal medicine were the top three departments that fungi were frequently detected. The mainly isolated fungal species were Candida albicans (43.97%, n=266), Candida glabrata (20.00%, n=121), and Candida tropicalis (17.02%, n=103), which contributed to over 80% of fungal infection. The susceptibility of the Candida spp. to echinocandins, 5-fluorocytosine, and amphotericin B remained above 95%, while C. glabrata and C. tropicalis to itraconazole were about 95%, and the dose-dependent susceptibility of C. glabrata to fluconazole was more than 90%. The echinocandins had no antifungal activity against Trichosporon asahi in vitro (MIC₉₀>8 μg/mL), but azole drugs were good, especially voriconazole and itraconazole (MIC₉₀ = 0.25 μg/mL).

Conclusion

The main causative agents of fungal infection were still the genus of Candida. Echinocandins were the first choice for clinical therapy of Candida infection, followed with 5-fluorocytosine and amphotericin B. Azole antifungal agents should be used with caution in Candida glabrata and Candida tropicalis infections.

Cryptococcosis in Southern China: Insights from a Six-Year Retrospective Study in Eastern Guangdong

Objective

Cryptococcosis is a fatal infection that can affect both immunocompetent and immunocompromised patients, and it is little understood in China's various regions. This research aimed to look at the epidemiology, risk factors, and antifungal susceptibility pattern of Cryptococcus neoformans in eastern Guangdong, China.

Methods

A six-year (2016-2022) retrospective study was conducted at Meizhou People's Hospital, China. Demographical, clinical, and laboratory data of cryptococcal patients were collected from hospital records and statistically analyzed using the chi-square and ANOVA tests.

Results

Overall, 170 cryptococcal infections were recorded, of which meningitis accounted for 78 (45.88%), cryptococcemia for 50 (29.41%), and pneumonia for 42 (24.7%). The number of cases increased 8-fold during the study duration. The median age of patients was 58 years (Inter quartile range: 47-66), and the high proportion of cases was from the male population (n = 121, 71.17%). The underlying diseases were identified only in 60 (35.29%) patients, of which 26 (15.29%) were severely immunocompromised, and 26 (15.29%) others were mildly immunocompromised. A statistically significant difference was reported for chronic renal failure, and anemia (p < 0.05) persisted in cases of three infection types. A high number of non-wild type (NWT) isolates were found against amphotericin B (n=13/145, 8.96%), followed by itraconazole (n=7/136, 5.15%) and voriconazole (n=4/158, 2.53%). Only six isolates (3.79%) were multidrug-resistant, four of which were from cryptococcemia patients. Compared to meningitis and pneumonia, cryptococcemia revealed a higher percentage of NWT isolates (p < 0.05).

Conclusion

In high-risk populations, cryptococcal infections require ongoing monitoring and management.

Potential Strategies to Control the Risk of Antifungal Resistance in Humans: A Comprehensive Review

Fungal infections are becoming one of the main causes of morbidity and mortality in people with weakened immune systems. Mycoses are becoming more common, despite greater knowledge and better treatment methods, due to the regular emergence of resistance to the antifungal medications used in clinical settings. Antifungal therapy is the mainstay of patient management for acute and chronic mycoses. However, the limited availability of antifungal drug classes limits the range of available treatments. Additionally, several drawbacks to treating mycoses include unfavourable side effects, a limited activity spectrum, a paucity of targets, and fungal resistance, all of which continue to be significant issues in developing antifungal drugs. The emergence of antifungal drug resistance has eliminated accessible drug classes as treatment choices, which significantly compromises the clinical management of fungal illnesses. In some situations, the emergence of strains resistant to many antifungal medications is a major concern. Although new medications have been developed to address this issue, antifungal drug resistance has grown more pronounced, particularly in patients who need long-term care or are undergoing antifungal prophylaxis. Moreover, the mechanisms that cause resistance must be well understood, including modifications in drug target affinities and abundances, along with biofilms and efflux pumps that diminish intracellular drug levels, to find novel antifungal drugs and drug targets. In this review, different classes of antifungal agents, and their resistance mechanisms, have been discussed. The latter part of the review focuses on the strategies by which we can overcome this serious issue of antifungal resistance in humans.

Evaluation of an Antifungal Stewardship Initiative Targeting Micafungin at an Academic Medical Center

Delays in the treatment of proven invasive fungal disease have been shown to be harmful. However, empiric treatment for all patients at risk of infection has not demonstrated benefit. This study evaluates the effects of a micafungin stewardship initiative on the duration of therapy and clinical outcomes at the University of Mississippi Medical Center in Jackson, Mississippi. This single-center quasi-experiment evaluated patients who received micafungin. Adult inpatients who received at least one treatment dose of micafungin in the pre-intervention (1 October 2020 to 30 September 2021) or post-intervention (1 October 2021 to 30 April 2022) groups were included. Patients were placed on micafungin for prophylaxis and those who required definitive micafungin therapy were excluded. An algorithm was used to provide real-time recommendations in order to assess change in the treatment days of micafungin therapy. A total of 282 patients were included (141 pre-group versus 141 post-group). Over 80% of the patients included in the study were in an intensive care unit, and other baseline characteristics were similar. The median number of treatment days with micafungin was 4 [IQR 3-6] in the pre-group and 3 [IQR 2-6] in the post-group (p = 0.005). Other endpoints, such as time to discontinuation or de-escalation, hospital mortality, and hospital length of stay, were not significantly different between the groups. An antifungal stewardship initiative can be an effective way to decrease unnecessary empiric antifungal therapy for patients who are at risk of invasive fugal disease.