Antifungal susceptibility and virulence determinants profile of candida species isolated from patients with candidemia.

Candida is the most prevalent fungal bloodstream infection (BSI) with a high mortality rate among hospitalized patients. Another concern facing physicians is rising global incidence of drug-resistant Candida. This study aimed to characterize the prevalence, antifungal susceptibility, biofilm formation, and virulence genes (HWP1, ALS1, SAP2) of different Candida spp. isolated from patients with candidemia. 52 isolates of Candida spp. were identified from blood cultures by chromogenic Candida agar and confirmed by the VITEK 2 system. Isolates were tested for antifungal susceptibility by disk diffusion and VITEK 2 system. Biofilm formation and investigated genes were detected by the Congo red method and conventional PCR, respectively. Candida spp. caused 2.3% of detected BSIs, of which 32.7% were caused by Candida albicans (C. albicans) and 67.3% by non-albicans Candida (NAC), with the predominance of C. tropicalis (25%), followed by C. parapsilosis (17.3%), and C. krusei (13.5%). The susceptibility rates to fluconazole, voriconazole, caspofungin, micafungin, amphotericin B, and flucytosine were 64.7%, 76.5%, 100.0%, 100%, 100.0%, and 100.0% in C. albicans, while 53.6%, 71.4%, 91.4%, 91.4%, 94.3%, and 94.3% in NAC, respectively. Biofilm production, HWP1, ALS1, and SAP2 were detected in 70.6%, 82.4%, 76.5%, and 52.9% of C. albicans and 74.3%, 85.7%, 80.0%, and 48.6% of NAC, respectively. There is remarkable shift to NAC BSIs and high azole resistance. Antifungal stewardship and analysis of risk factors associated with this shift are needed.

Analysis of candidemia cases in a city hospital during the COVID-19 pandemic.

OBJECTIVE: The frequency and mortality of candidemia remain important. Non-albicans Candida species such as C. auris are increasing. PATIENTS AND METHODS: A retrospective review of adult patients diagnosed with bloodstream infection due to Candida species in the 17 months between July 1, 2020, and December 1, 2021, was performed. Yeast colonies grown in culture were identified by matrix-assisted laser desorption/ionization time-of-flight. Antifungal susceptibility tests of Candida strains were performed with Sensititre YeastOne (TREK Diagnostic Systems Inc., Westlake, Ohio) kits, and minimum inhibitory concentration values were evaluated according to the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints. RESULTS: In total, 217 patients (mean age 64.9±15.7 years) were included. C. albicans was the most common fungus (detected in 82 patients; 37.8%), followed by C. parapsilosis (17.1%), C. glabrata (15.2%), C. tropicalis (15.2%), and C. auris (9%). Candidemia developed in 175 (81.4%) of the cases during their intensive care unit stay. Fluconazole (41.0%) and caspofungin (36.4%) were the two most frequently used antifungal agents in antifungal therapy. There were 114 (52.3%) deaths in the study group. Mortality rates were found to be lower in patients infected with C. parapsilosis or C. auris. Age and previous COVID-19 infection were other important risk factors. When the 217 Candida spp. were examined, resistance and intermediate susceptibility results were higher when EUCAST criteria were used. While the two methods were found to be fully compatible only for fluconazole, a partial agreement was also observed for voriconazole. CONCLUSIONS: As our study observed, the COVID-19 pandemic brought increasing numbers of immunosuppressed patients, widespread use of antibacterials, and central venous catheters, increasing the frequency and mortality of candidemia cases. All health institutions should be prepared for the diagnosis and treatment of candidemia. In addition, C. auris, the frequency of which has increased in recent years, is a new factor that should be considered in candidemia cases.

Early Prediction of Bloodstream Infection with Complete Blood Count Parameters: an Ex-Vivo Human Whole Blood Model.

BACKGROUND: Despite the advanced laboratory technologies available today, blood culture is the gold standard method in the diagnosis of bloodstream infections. Automated blood culture devices give blood culture results for laboratories approximately in 2 - 3 days up to 7 days. Moreover, some microorganisms like nonreproducible bacteria, fungi or viruses cannot be produced in culture. Among all samples taken for blood culture on suspicion of infection approximately 10% are determined as positive whereas the false positive rate due to contamination is 5%. Especially in life-threatening severe conditions such as sepsis early diagnosis and prompt treatment are crucial. Based on this the aim of this study is to investigate complete blood count parameters as potential early markers in Escherichia coli, Staphylococcus aureus and Candida albicans bloodstream infections using an ex vivo whole blood model. METHODS: Blood samples collected from healthy donors (n = 10) were treated with suspensions containing a certain concentration of microorganisms (107 CFU/mL for both E. coli ATCC 25922 and S. aureus ATCC 29213, 106 CFU/mL for C. albicans ATCC 14053). After bacteremia and candidemia were induced, complete blood count parameters were analyzed hourly in the samples until the end of the 4th hour with a Mindray BC-6800 hematology analyzer. Statistical analysis was performed by Tukey-Kramer post-hoc multiple comparison test and statistical significance was accepted as p < 0.05. RESULTS: When platelet derived parameter baseline values were compared to hourly values in E. coli and S. aureus induced whole blood samples, it was found that the decrease in PLT, P-LCC and the increase in IPF% was significant from the first hour whereas the increase in IMG% was found to be significant only from the 3rd hour onward. In the experiments with C. albicans, it was observed that the increase in IPF% and IMG% was significant from the 2nd and 3rd hour onward, respectively. There was no relationship between MPV, P-LCR, and NLR baseline and hourly results in any microorganism induced model. CONCLUSIONS: IPF% can guide clinicians in the early diagnosis and management of treatment of infections caused by S. aureus, E. coli, and C. albicans.

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.

Association of persistent positive blood cultures and infective endocarditis: A cohort study among patients with suspected infective endocarditis.

OBJECTIVES: To ascertain whether infective endocarditis (IE) was associated with persistent bacteraemia/candidaemia among patients with suspected IE. METHODS: This study included bacteraemic/candidaemic adult patients with echocardiography and follow-up blood cultures. Persistent bacteraemia/candidaemia was defined as continued positive blood cultures with the same microorganism for 48 h or more after antibiotic treatment initiation. Each case was classified for IE by the Endocarditis Team. RESULTS: Among 1962 episodes of suspected IE, IE (605; 31%) was the most prevalent infection type. Persistent bacteraemia/candidaemia was observed in 426 (22%) episodes. Persistent bacteraemia was more common among episodes with Staphylococcus aureus bacteraemia compared to episodes with positive blood cultures for other pathogens (32%, 298/933 vs 12%, 128/1029; P < 0.001). Multivariable analysis demonstrated that cardiac predisposing factors (aOR 1.84, 95% CI 1.31-2.60), community or non-nosocomial healthcare-associated (2.85, 2.10-3.88), bacteraemia by high-risk bacteria, such as S. aureus, streptococci, enterococci or HACEK (1.84, 1.31-2.60), two or more positive sets of index blood cultures (6.99, 4.60-10.63), persistent bacteraemia/candidaemia for 48 h from antimicrobial treatment initiation (1.43, 1.05-1.93), embolic events within 48h from antimicrobial treatment initiation (12.81, 9.43-17.41), and immunological phenomena (3.87, 1.09-1.78) were associated with infective endocarditis. CONCLUSIONS: IE was associated with persistent bacteraemia/candidaemia, along with other commonly associated factors.

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.

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.

COVID-19 associated candidemia: From a shift in fungal epidemiology to a rise in azole drug resistance.

Our understanding of fungal epidemiology and the burden of antifungal drug resistance in COVID-19-associated candidemia (CAC) patients is limited. Therefore, we conducted a retrospective multicenter study in Iran to explore clinical and microbiological profiles of CAC patients. Yeast isolated from blood, were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and subjected to antifungal susceptibility testing (AFST) using the broth microdilution method M27-A3 protocol. A total of 0.6% of the COVID-19 patients acquired CAC (43/6174). Fluconazole was the most widely used antifungal, and 37% of patients were not treated. Contrary to historic candidemia patients, Candida albicans and C. tropicalis were the most common species. In vitro resistance was high and only noted for azoles; 50%, 20%, and 13.6% of patients were infected with azole-non-susceptible (ANS) C. tropicalis, C. parapsilosis, and C. albicans isolates, respectively. ERG11 mutations conferring azole resistance were detected for C. parapsilosis isolates (Y132F), recovered from an azole-naïve patient. Our study revealed an unprecedented rise in ANS Candida isolates, including the first C. parapsilosis isolate carrying Y132F, among CAC patients in Iran, which potentially threatens the efficacy of fluconazole, the most widely used drug in our centers. Considering the high mortality rate and 37% of untreated CAC cases, our study underscores the importance of infection control strategies and antifungal stewardship to minimize the emergence of ANS Candida isolates during COVID-19.

Invasive candidiasis.

Invasive candidiasis is an important fungal disease caused by Candida albicans and, increasingly, non-albicans Candida pathogens. Invasive Candida infections originate most frequently from endogenous human reservoirs and are triggered by impaired host defences. Signs and symptoms of invasive candidiasis are non-specific; candidaemia is the most diagnosed manifestation, with disseminated candidiasis affecting single or multiple organs. Diagnosis poses many challenges, and conventional culture techniques are frequently supplemented by non-culture-based assays. The attributable mortality from candidaemia and disseminated infections is ~30%. Fluconazole resistance is a concern for Nakaseomyces glabratus, Candida parapsilosis, and Candida auris and less so in Candida tropicalis infection; acquired echinocandin resistance remains uncommon. The epidemiology of invasive candidiasis varies in different geographical areas and within various patient populations. Risk factors include intensive care unit stay, central venous catheter use, broad-spectrum antibiotics use, abdominal surgery and immune suppression. Early antifungal treatment and central venous catheter removal form the cornerstones to decrease mortality. The landscape of novel therapeutics is growing; however, the application of new drugs requires careful selection of eligible patients as the spectrum of activity is limited to a few fungal species. Unanswered questions and knowledge gaps define future research priorities and a personalized approach to diagnosis and treatment of invasive candidiasis is of paramount importance.

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.

Outcomes by Candida spp. in the ReSTORE Phase 3 trial of rezafungin versus caspofungin for candidemia and/or invasive candidiasis.

Rezafungin is a long-acting, intravenously administered echinocandin for the treatment of candidemia and invasive candidiasis (IC). Non-inferiority of rezafungin vs caspofungin for the treatment of adults with candidemia and/or IC was demonstrated in the Phase 3 ReSTORE study based on the primary endpoints of day 14 global cure and 30-day all-cause mortality. Here, an analysis of ReSTORE data evaluating efficacy outcomes by baseline Candida species is described. Susceptibility testing was performed for Candida species using the Clinical and Laboratory Standards Institute reference broth microdilution method. There were 93 patients in the modified intent-to-treat population who received rezafungin; 94 received caspofungin. Baseline Candida species distribution was similar in the two treatment groups; C. albicans (occurring in 41.9% and 42.6% of patients in the rezafungin and caspofungin groups, respectively), C. glabrata (25.8% and 26.6%), and C. tropicalis (21.5% and 18.1%) were the most common pathogens. Rates of global cure and mycological eradication at day 14 and day 30 all-cause mortality by Candida species were comparable in the rezafungin and caspofungin treatment groups and did not appear to be impacted by minimal inhibitory concentration (MIC) values for either rezafungin or caspofungin. Two patients had baseline isolates with non-susceptible MIC values (both in the rezafungin group: one non-susceptible to rezafungin and one to caspofungin, classified as intermediate); both were candidemia-only patients in whom rezafungin treatment was successful based on the day 30 all-cause mortality endpoint. This analysis of ReSTORE demonstrated the efficacy of rezafungin for candidemia and IC in patients infected with a variety of Candida species.

Risk factors associated with fluconazole resistance in Candida parapsilosis candidemia: A case-case study.

BACKGROUND: Candida species are among the most important invasive pathogens in intensive care units (ICUs). Non-albicans species including Candida parapsilosis (C. parapsilosis) has increased in recent years. Fluconazole is the leading antifungal agent but resistance is a concern among C. parapsilosis species. OBJECTIVES: The aim of this study was to determine the factors associated with fluconazole resistance in patients with candidemia due to C. parapsilosis in ICUs. METHODS: This case-case study was conducted in a 750-bed, tertiary hospital between 2015 and 2021. Patients with fluconazole-resistant C. parapsilosis candidemia constituted the 'cases of interest' group and patients with fluconazole-susceptible C. parapsilosis candidemia constituted the 'comparison cases' group. Demographic and clinical data of the patients were recorded. Logistic regression analysis was performed using the backward elimination method to determine the independent predictors of fluconazole-resistant C. parapsilosis bloodstream infections. RESULTS: The study included 177 patients. In the cultures of these patients, 76 (43%) fluconazole-resistant, 13 (7.3%) fluconazole-reduced susceptible, and 88 (49.7%) fluconazole-susceptible isolates were found. In the regression analysis the risk factors for fluconazole-resistant C. parapsilosis bloodstream infection, malignancy, immunosuppressive treatment, history of intra-abdominal surgery, hypoalbunemia, previous fluconazole use, and SOFA score were found to be associated in univariate analysis. In multivariate regression analysis, history of intra-abdominal surgery (OR: 2.16; 95% CI: 1.05-4.44), hypoalbuminemia (OR: 2.56; 95% CI: 1.06-6.17) and previous fluconazole use (OR: 3.35; 95% CI: 1.02-11) were found to be independent predictors. CONCLUSIONS: In this study, a significant correlation was found between candidemia due to fluconazole-resistant C. parapsilosis in ICUs and intra-abdominal surgery, hypoalbuminemia, and previous fluconazole use. C. parapsilosis isolates and fluconazole resistance should be continuously monitored, strict infection control measures should be taken and antifungal stewardship programs should be implemented.

Comparative assessment of Sensititre YeastOne and Micronaut-AM EUCAST for antifungal susceptibility testing in candidaemia isolates.

PURPOSE: Antifungal susceptibility testing (AFST) is essential to ensure appropriate antifungal therapy in candidaemia. This study compared two commercial colorimetric broth microdilution tests: Sensititre YeastOne (SYO; Thermo Scientific) and Micronaut-AM EUCAST AFST (M-AM; Bruker) for the AFST of Candida spp. MATERIAL AND METHODS: A total of 74 yeast strains, including C. albicans (n = 40) and non-albicans Candida species (NACS) (n = 34), were obtained from blood cultures of patients admitted to a tertiary care hospital in Belgium from 2017 to 2022. AFST by SYO and by M-AM were performed according to the manufacturers' protocols and interpreted using CLSI and EUCAST guidelines, respectively. Essential and categorical agreements (EA and CA), very major, major and minor discrepancies were calculated for amphotericin B, echinocandins and azoles considering SYO as the reference method. RESULTS: In total, 441 and 392 isolate-antifungal results were evaluable for EA and CA, respectively. SYO and M-AM, showed a high level of concordance for C. albicans strains, with an EA and CA ≥90 % for all tested antifungals. However, we noted significant discordances for NACS, the lowest EA were observed with micafungin (50 %) and voriconazole (58.8 %). These discrepancies were likely due to differences in the raw MIC values obtained by the two methods and the different interpretation breakpoints used by CLSI and EUCAST. CONCLUSION: Our study showed excellent agreement between SYO and M-AM for AFST of C. albicans, while the equivalency was lower for NACS. AFST method should be carefully selected, considering the results might impact the choice of antifungals for non-albicans candidaemia.

First report of Candida auris in Guangdong, China: clinical and microbiological characteristics of 7 episodes of candidemia.

Candida auris is an emerging multidrug-resistant fungal pathogen worldwide. To date, it has not been reported in Guangdong, China. For the first time, we reported 7 cases of C. auris candidemia from two hospitals in Guangdong. The clinical and microbiological characteristics of these cases were investigated carefully. Two geographic clades, i.e. III and I, were found popular in different hospitals by whole genome sequencing analyses. All C. auris isolates from bloodstream were resistant to fluconazole, 5 of which belonged to Clade III harbouring VF125AL mutation in the ERG11 gene. The isolates with Clade I presented Y132F mutation in the ERG11 gene as well as resistance to amphotericin B. All isolates exhibited strong biofilm-forming capacity and non-aggregative phenotype. The mean time from admission to onset of C. auris candidemia was 39.4 days (range: 12 - 80 days). Despite performing appropriate therapeutic regimen, 42.9% (3/7) of patients experienced occurrences of C. auris candidemia and colonization after the first positive bloodstream. C. auris colonization was still observed after the first C. auris candidemia for 81 days in some patient. Microbiologic eradication from bloodstream was achieved in 85.7% (6/7) of patients at discharge. In conclusion, this study offers a crucial insight into unravelling the multiple origins of C. auris in Guangdong, highlighting great challenges in clinical prevention and control.

Genomic description of acquired fluconazole- and echinocandin-resistance in patients with serial Candida glabrata isolates.

Candida glabrata is one of the most common causes of systemic candidiasis, often resistant to antifungal medications. To describe the genomic context of emerging resistance, we conducted a retrospective analysis of 82 serially collected isolates from 33 patients from population-based candidemia surveillance in the United States. We used whole-genome sequencing to determine the genetic relationships between isolates obtained from the same patient. Phylogenetic analysis demonstrated that isolates from 29 patients were clustered by patient. The median SNPs between isolates from the same patient was 30 (range: 7-96 SNPs), while unrelated strains infected four patients. Twenty-one isolates were resistant to echinocandins, and 24 were resistant to fluconazole. All echinocandin-resistant isolates carried a mutation either in the FKS1 or FKS2 HS1 region. Of the 24 fluconazole-resistant isolates, 17 (71%) had non-synonymous polymorphisms in the PDR1 gene, which were absent in susceptible isolates. In 11 patients, a genetically related resistant isolate was collected after recovering susceptible isolates, indicating in vivo acquisition of resistance. These findings allowed us to estimate the intra-host diversity of C. glabrata and propose an upper boundary of 96 SNPs for defining genetically related isolates, which can be used to assess donor-to-host transmission, nosocomial transmission, or acquired resistance. IMPORTANCE In our study, mutations associated to azole resistance and echinocandin resistance were detected in Candida glabrata isolates using a whole-genome sequence. C. glabrata is the second most common cause of candidemia in the United States, which rapidly acquires resistance to antifungals, in vitro and in vivo.

Utility of incorporation of beta-D-glucan and T2Candida testing for diagnosis and treatment of candidemia.

The additive role of non-culture-based methods for the diagnosis of candidemia remains unknown. We evaluated 2 clinical practices followed in our hospitals for the diagnosis of candidemia, namely practice#1 including a combination of blood cultures and T2Candida, and practice#2 that also included Beta-D-glucan (BDG). Three out of 96 patients testing positive with practice#1 received a complete antifungal course. Of the 120 patients evaluated with practice#2, 29 were positive. Only 55.2% of those received a complete course. We observed significant differences in antifungal utilization, with 268.5 antifungal days/1000 patient-days for practice#1, as opposed to 371.9 days for practice#2, a nearly 40% difference. However, we found similar rates of antifungal discontinuation among negative patients at 3 days of testing (36.8% and 37.0% respectively). No differences were detected in death and/or subsequent diagnosis of candidemia. In summary, addition of BDG was interpreted variably by clinicians, was associated with an increase in antifungal utilization, and did not correlate with measurable clinical benefits for patients.

Natural history and prognostic factors of candidemia in kidney transplant recipients: A retrospective, multinational study.

BACKGROUND: The natural history of candidemia in kidney transplant recipients (KTR) remains poorly understood. This study aimed to evaluate mortality, prognostic factors and overall graft loss after candidemia in KTRs. METHODS: This is a retrospective multicentre study enrolling all KTRs ≥15 years old with candidemia diagnosed at hospitals in Brazil, Spain and Italy from 2010 to 2020. Primary endpoints were mortality rates at 14 and 30 days. Secondary endpoints were prognostic factors of 14-day mortality and overall graft loss. RESULTS: We enrolled 93 KTRs of which 75 were from Brazil. The mean time interval from transplantation to the onset of candidemia was 45.2 ± 61.5 months. 42% of all patients were on haemodialysis, 31.3% had an episode of sepsis and 39% underwent surgery within 30 days before fungemia. European patients were more likely to receive echinocandin (32 vs. 72%, p < .001). 22.7% of Brazilian patients did not receive any antifungal before death. All-cause mortality at 14 days was higher in Brazil (41.3 vs. 11.1%, p = .016). Candida colonisation (OR 6.91 [95% CI: 1.08-44.3], p = .042) and hypotension (OR 4.87 [95% CI: 1.62-14.66], p = .005) were associated with 14-day mortality. Echinocandin treatment had a protective effect (OR 0.19 [95% CI: 0.05-0.73], p = .015). Graft loss at 90 days occurred in 48% of patients (70.7 in Brazil vs. 22.2% in Europe, p < .01). CONCLUSIONS: Candidemia in KTR is usually documented late after engraftment in patients requiring HD, surgical procedures and dysbiosis secondary to antibiotic use. Mortality was higher in Brazil. Echinocandin therapy was associated with improved survival.

Questioning the 14-day dogma in candidemia treatment duration.

The growing threat of antimicrobial resistance (AMR) is a global concern. With AMR directly causing 1.27 million deaths in 2019 and projections of up to 10 million annual deaths by 2050, optimising infectious disease treatments is imperative. Prudent antimicrobial use, including treatment duration, can mitigate AMR emergence. This is particularly critical in candidemia, a severe condition with a 45% crude mortality rate, as the 14-day minimum treatment period has not been challenged in randomised comparison. A comprehensive literature search was conducted in August 2023, revealing seven original articles and two case series discussing treatment durations of less than 14 days for candidemia. No interventional trials or prospective observational studies assessing shorter durations were found. Historical studies showed varying candidemia treatment durations, questioning the current 14-day minimum recommendation. Recent research observed no significant survival differences between patients receiving shorter or longer treatment, emphasising the need for evidence-based guidance. Treatment duration reduction post-blood culture clearance could decrease exposure to antifungal drugs, limiting selection pressure, especially in the context of emerging multiresistant Candida species. Candidemia's complexity, emerging resistance and potential for shorter in-hospital stays underscore the urgency of refining treatment strategies. Evidence-driven candidemia treatment durations are imperative to balance efficacy with resistance prevention and ensure the longevity of antifungal therapies. Further research and clinical trials are needed to establish evidence-based guidelines for candidemia treatment duration.

Unresolved issues in the diagnosis of catheter related candidemia: A position paper.

The incidence and recent trends of candidemia and the contribution of the COVID-19 pandemic to its evolution are not well documented. The catheter is a major focus of Candida spp. infections, but the methods used to confirm the origin of candidemia are still based on the data generated for bacterial infection. The presence of Candida spp. on the tip of a removed catheter is the gold standard for confirmation but it is not always possible to remove it. Conservative methods, without catheter removal, have not been specifically studied for microorganisms whose times of growth are different from those of bacteria and therefore these results are not applicable to candidemia. The different Candida species do not have a particular tropism for catheter colonization and fungal biomarkers have not yet been able to contribute to the determination of the origin of candidemia. Techniques such Candida T2 Magnetic Resonance (T2MR) has not yet been applied for this purpose. Finally, there is not yet a consensus of how to proceed when Candida spp. is isolated from an extracted catheter and blood cultures obtained from simultaneous peripheral veins are negative. In this lack of firm data, a group of experts has formulated a series of questions trying to answer them based on the literature, indicating the current deficiencies and offering their own opinion. All authors agree with the conclusions of the manuscript and offer it as a position and discussion paper.