Candidemia in Adults at a Tertiary Hospital in China: Clinical Characteristics, Species Distribution, Resistance, and Outcomes

Distribution and antifungal susceptibility profiles of Candida species isolated from candidemia patients admitted to Egyptian tertiary hospitals: a cross-sectional study

BACKGROUND

Candidemia is a widespread threat that can lead to significant complications in healthcare settings.

OBJECTIVES

Our study aimed to identify isolates of Candida isolated from blood culture bottles of patients with candidemia and assess their antifungal susceptibility profiles.

METHODS

We conducted a cross-sectional study at Cairo University tertiary care hospitals over 16 months including 90 patients. Candida isolates were collected from blood culture bottles, and identified using MALDI-TOF MS technology of VITEK MS PRIME (bioMérieux) with the corresponding database VITEK IVD Database 3.2. followed by antifungal susceptibility testing using VITEK 2 Compact system.

RESULTS

Candida albicans was the most common species isolated from both pediatric and adult patients with percentages of 47.3% and 36.4% respectively, followed by Candida parapsilosis with percentages of 32.6% and 25.0% respectively. Voriconazole showed the highest antifungal activity at 90.9% of isolates in adults and 95.7% in pediatrics, followed by caspofungin and micafungin. The mean hospital stays for adults ranged from 8 to 30 days and from 10 to 42 days in the pediatric group.

CONCLUSIONS

C. albicans remains the predominant species isolated from both pediatric and adult candidemia patients, despite a notable increase in other species. C. tropicalis and C. parapsilosis are considered the most common non-albicans Candida (NAC) species. The rise in Candida species other than albicans highlights the urgent need for effective antifungal stewardship programs. Voriconazole exhibited the higher antifungal activity followed by caspofungin and micafungin.

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.

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.

The Epidemiology and Clinical Characteristics of Fungemia in a Tertiary Hospital in Southern China: A 6-Year Retrospective Study

Knowledge of the epidemiology and clinical characteristics of fungemia in southern China is limited. We conducted a six-year retrospective descriptive study to analyze the epidemiological and clinical characteristics of fungemia at the largest tertiary hospital in Guangxi, southern China. Data were obtained from the laboratory registry of patients with fungemia between January 2014 and December 2019. Demographic characteristics, underlying medical conditions, and outcomes for each case were analyzed. A total of 455 patients with fungemia were identified. Unexpectedly, Talaromyces marneffei (T. marneffei) was the most frequently isolated agent causing fungemia in the region (149/475, 31.4%), and Candida albicans (C. albicans) was the most commonly isolated Candida spp. (100/475, 21.1%). We identified that more than 70% of talaromycosis fungemia developed in AIDS patients, whereas candidemia was most commonly associated with a history of recent surgery. Notably, the total mortality rate of fungemia and the mortality rate in patients with T. marneffei and Cryptococcus neoformans (C. neoformans) fungemia were significantly higher in HIV-uninfected patients than in HIV-infected patients. In conclusion, the clinical pattern of fungemia in Guangxi is different from that in previous studies. Our study may provide new guidance for the early diagnosis and prompt treatment of fungemia in similar geographic regions.

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

Antifungal resistance to Candida pathogens increases morbidity and mortality of immunosuppressive patients, an emerging crisis worldwide. Understanding the Candida prevalence and antifungal susceptibility pattern is necessary to control and treat candidiasis. We aimed to systematically analyse the susceptibility profiles of Candida species published in the last ten years (December 2011 to December 2021) from mainland China. The studies were collected from PubMed, Google Scholar, and Science Direct search engines. Out of 89 included studies, a total of 44,716 Candida isolates were collected, mainly comprising C. albicans (49.36%), C. tropicalis (21.89%), C. parapsilosis (13.92%), and C. glabrata (11.37%). The lowest susceptibility was detected for azole group; fluconazole susceptibilities against C. parapsilosis, C. albicans, C. glabrata, C. tropicalis, C. guilliermondii, C. pelliculosa, and C. auris were 93.25%, 91.6%, 79.4%, 77.95%, 76%, 50%, and 0% respectively. Amphotericin B and anidulafungin were the most susceptible drugs for all Candida species. Resistance to azole was mainly linked with mutations in ERG11, ERG3, ERG4, MRR1-2, MSH-2, and PDR-1 genes. Mutation in FKS-1 and FKS-2 in C. auris and C. glabrata causing resistance to echinocandins was stated in two studies. Gaps in the studies' characteristics were detected, such as 79.77%, 47.19 %, 26.97%, 7.86%, and 4.49% studies did not mention the mortality rates, age, gender, breakpoint reference guidelines, and fungal identification method, respectively. The current study demonstrates the overall antifungal susceptibility pattern of Candida species, gaps in surveillance studies and risk-reduction strategies that could be supportive in candidiasis therapy and for the researchers in their future studies.

Prevalence and species distribution of Candida bloodstream infection in children and adults in two teaching university hospitals in Egypt: first report of Candida kefyr

BACKGROUND

Candidemia is a pervasive problem associated with significant morbidity and mortality in health care settings. This study aimed to determine the changing distribution of Candida species and the emergence of uncommon species.

METHODS

This was a cross-sectional study performed in two Cairo University hospitals between 2019 and 2020. All Candida species isolates recovered from blood cultures of adults and pediatrics patients admitted to the hospitals were included. Candida isolates were identified by chromogenic Candida agar and Vitek2 YST identification card. Candida kefyr was confirmed by chip array.

RESULTS

Candida species were responsible for 1.6% of bloodstream infections in adults and 10.8% in pediatric patients. C. albicans was the most prevalent species representing 27.8% in adults and 48.3% in pediatrics. Non-albicans species (NAC) represented the most isolated Candida species among adults and pediatrics (72.2% and 51.6%, respectively) with the predominance of C. tropicalis (27.8% and 22.5%, respectively) followed by C. parapsilosis (16.7% and 10.8%, respectively). The uncommon Candida, which is Candida species other than C. albicans, C. parapsilosis, C. tropicalis, C. glabrata, and C. krusei, represents 16.6% and 14% of all candidemia in adults and pediatrics, respectively. Only one of each of C. lusitaniae, C. utilis, and C. kefyr were detected in adults. C. lusitaniae was the most frequently recovered uncommon Candida among pediatrics resulting in 6.4% of candidemia followed by C. famata (4.3%), C. utilis (2.2%), and C. kefyr (1.1%).

CONCLUSIONS

C. albicans is still the primary species isolated from pediatrics and adults with candidemia despite the considerable shift to the non-albicans species. C. tropicalis and C. parapsilosis are the most prevalent NAC. The increased prevalence of uncommon Candida species is alarming and necessitates a prompt stewardship program.

Epidemiology of nosocomial candidemia, mortality and antifungal resistance, 7-year experience, in Turkey

Candidemia is an important clinical condition that prolongs the period of hospitalization and increases morbidity, mortality, and hospital costs. In this retrospective study, we aimed to evaluate the epidemiological and microbiological characteristics of patients with candidemia, between January 2013 and December 2019. Two hundred forty-one candidemia episodes were observed in the 230 patients, of whom 45% were female. The median age was 63 and 53.9% of the episodes were in the ICU. Frequently observed predisposing factors for candidemia included the use of antibiotics (71.3%), urinary catheterization (56.3%), Central venous catheter placement (50.3%), total parenteral nutrition (47.9%), solid-organ malignancy (46%), a surgical intervention (48.6%), chemotherapy (37%), steroid treatment (25.5%). The crude mortality rate was 52.7%. A significant difference was found between survivors and non-survivors (p = 0.007) with the Charlson comorbidity index. However, no statistically significant association was found between mortality and age, sex, surgical intervention, catheter-related candidemia, or Candida spp. The most frequently isolated Candida spp. was C. albicans (51%). Overall resistance to fluconazole, voriconazole, caspofungin, micafungin and flucytosine was 3.7%, 0%, 2.5%, 1.8%,1.8%, respectively. Consequently, there is a need for tests that yield higher success rates and rapid in diagnosis candidemia and local epidemiological data for antifungal resistance.

Changing Trends of Candida Species and Antifungal Susceptibility Profile of Candida Bloodstream Isolates: A 5-Year Retrospective Survey

Background: Candida species have emerged as one of the most common causes of bloodstream infections (BSIs). There are limited data on the distribution of Candida spp. and susceptibility by year. Objectives: In this study, we analyzed changes in the distribution of Candida spp. and their antifungal susceptibility profiles from blood cultures. Methods: Records from January 2016 to December 2020 were obtained from the microbiology laboratory in Istanbul. Antifungal susceptibility tests were performed using the VITEK 2 compact system and evaluated according to EUCAST breakpoints. A total of 241 unique candidemia episodes were included in this study. Results: Candida albicans was the predominant pathogen (n = 95, 39.42%), followed by C. parapsilosis (n = 82, 34.02%), C. glabrata (n = 18, 7.47%), C. tropicalis (n = 17, 7.05%), C. krusei (n = 15, 6.22%), and other Candida spp. (n = 14, 5.79%). There was no statistically significant difference in the percentage of episodes of Candida spp. After data analysis, a tendency to shift from C. albicans to C. parapsilosis was observed in the period analyzed in this study. Candida albicans was the most common species in intensive care units (ICUs), hematology and hemopoietic stem cell transplantation units, and surgical clinics, with C. parapsilosis predominant in medical clinics. In general, micafungin susceptibility was the highest, and fluconazole was the lowest. There was reduced sensitivity to fluconazole and voriconazole for C. albicans and C. parapsilosis over 5 years. Conclusions: Detecting changes in the distribution of Candida spp. and antifungal susceptibility over time will lead to the selection of appropriate empirical therapy and monitor phenomena of antifungal resistance. Empirical treatment with antifungal agents is associated with high costs, toxicities, and risk of antifungal resistance. Therefore, it is mandatory to determine and monitor Candida spp. and antifungal susceptibility testing to select appropriate antifungal agents.

Molecular Identification and Antifungal Susceptibility Patterns of Candida Species Isolated from Candidemia Patients in Yasuj, Southwestern Iran

Background: Candidemia is the most common systemic infection in hospitalized patients causing high mortality. Hence, the diagnosis of this infection in the early stage with appropriate antifungal therapy is paramount. Objectives: The study aimed at molecular identification of Candida species isolated from candidemia patients and evaluation of the in vitro antifungal susceptibility patterns of these strains to fluconazole, amphotericin B, and caspofungin. Methods: In the present study, 800 hospitalized patients who were suspected to have candidemia were sampled. Candida species were isolated and identified based on morphological characteristics and PCR-sequencing of the ITS1-5.8S-ITS2 region. Antifungal susceptibility tests for fluconazole, amphotericin B, and caspofungin were performed according to the Clinical and Laboratory Standards Institute protocol M27-A3. Also, clinical data were recorded from the patients' records. Results: Twenty-seven patients among the sample of hospitalized patients were found to have candidemia. A total of 33.3% of candidemia patients were treated with amphotericin B, in which case the mortality rate was 14.8%. The majority of patients (59%) were from the neonatal intensive care unit, and premature birth was the most common underlying condition. Candida albicans (n = 18; 66.6%) was the most common species isolated from blood cultures, followed by C. parapsilosis (n = 7; 25.9%), C. pelliculosa (n = 1; 3.7%), and C. tropicalis (n = 1; 3.7%). Only one C. albicans isolate resistant to fluconazole (minimum inhibitory concentration = 32 µg/mL). Conclusions: Generally, C. albicans has been the most frequent causative agent of candidemia. Resistance to antifungal drugs among candidemia agents was rare. Also, the identification of Candida isolates at the species level with in vitro antifungal susceptibility tests helps manage candidemia patients better and decrease the mortality rate among them.

Risk Factors for Mortality in Colombian Patients with Candidemia

The aim of the study was to describe the microbiology and susceptibility profile of candidemia and to identify the risk factors associated with mortality in Colombia. A cohort of patients was followed for 30 days during 2008 to 2010. Microbiological identification and susceptibility assessments were performed in a reference centre. Demographic, clinical and treatment variables were evaluated for their associations with mortality. A parametric survival regression analysis was used to identify the risk factors associated with mortality. A total of 109 patients with candidemia in four hospitals in Colombia were identified, with a median age of 30 years old. C. parapsilosis was the most frequently identified microorganism (38.5%); the susceptibility of all isolates was high to fluconazole and anidulafungin, except for C. glabrata isolates. The overall mortality was 35.7%, and the risk factors associated with mortality included lack of antifungal treatment (HR 5.5, 95% CI 3.6–11.4), cancer (HR 3.9, 95% CI 2.3–8.0), diabetes (HR 2.5, 95% CI 1.03–6.4), and age (HR 1.13 per every 10 years, 95% CI 1.02–1.24). Catheter removal was associated with a low mortality rate (HR 0.06, 95% CI 0.00–0.49). Prompt antifungal treatment, better glycemic control and catheter removal should be prioritized in the management of candidemia.

Mycopathologia 2020: Legacy and Change to Remain Relevant for Content, Creation, and Communication

The 2020 COVID-19 pandemic had a profound impact on the publishing landscape. The 'pre-peer-review' publication model is likely to become common as a lag in publishing is not acceptable in a pandemic or other time! Mycopathologia is well placed to adopt such changes with its improved editorial processes, article formats, author engagements, and published articles' access and citation. Mycopathologia had an improved journal impact factor and article downloads in 2018-2019. A limited sampling suggested a slight decrease in the total submissions in 2019 (352 articles) compared to 2018 (371 articles). However, the acceptance rate improved to 30% in 2019 from 19% in 2018. Nearly half of all submissions in 2019 were rejected before peer-review or transferred to other Springer Nature journals. The published articles were contributed from 34 different countries, with authors from China, the USA, and Brazil among the top three contributors. An enhanced editorial oversight allowed peer-reviewers to focus on fewer articles that were well-matched to their expertise, which led to lower rejection rates post-peer-review. The introduction of MycopathologiaGENOME and MycopathologiaIMAGE article types received a good reception with notable downloads and citations.

A seven-year surveillance study of the epidemiology, antifungal susceptibility, risk factors and mortality of candidaemia among paediatric and adult inpatients in a tertiary teaching hospital in China

Background

There are no current national estimates of the candidaemia burden in China, and epidemiological candidaemia data from the underdeveloped region of China are lacking.

Methods

A 7-year retrospective study was carried out to analyse the prevalence, species distribution, antifungal susceptibility, risk factors and inpatient mortality of candidaemia among paediatric and adult patients in a regional tertiary teaching hospital in China.

Results

During the seven-year study period, a total of 201 inpatients with candidaemia were identified. The median age of the patients was 65 years (range, 1 day to 92 years), and 114 of the patients (56.7%) were male. The mean annual incidence of candidaemia was 0.26 cases per 1000 admissions (0.42 cases per 1000 paediatric admissions vs 0.24 cases per 1000 adult admissions, P < 0.05). Candida albicans was the most common fungal species (81/201, 40.3%) in all patients, Candida glabrata was the most common fungal species (18/35, 51.4%) in paediatric patients. Most isolates were susceptible to flucytosine (99.0%) and amphotericin B (99.0%), and the activity of antifungal agents against Candida species was no significant difference in satisfaction between paediatric and adult patients (P > 0.05). The all-cause mortality rate was 20.4% (paediatric patients: 11.4% vs adult patients:22.3%, P > 0.05). Fewer univariate predictors of poor outcomes were identified for paediatric patients than for adult patients (4 vs 11 predictors). Respiratory dysfunction and septic shock were independent predictors of 30-day mortality for all patients.

Conclusions

The epidemiological data of candidaemia in paediatric and adult patients are only different in the distributions of Candida species and the mean annual incidence of candidaemia. Flucytosine and amphotericin B can be used as first-choice agents when no antifungal susceptibility test results are available.

Infección invasiva por Candida spp. En pacientes inmunocomprometidos: Descripción de curso clínico experiencia diagnóstica, manejo y seguimiento en centro de alta complejidad

Introducción: Candida spp. Es la principal causa de fungemia, cuya incidencia ha aumentado en los últimos años. Existen datos locales insuficientes sobre este tipo de infecciones. Materiales y métodos: Este fue un estudio observacional retrospectivo de 44 pacientes diagnosticados con candidiasis invasiva hospitalizados en la Fundación Valle del Lili, el cual es un centro de cuarto nivel afiliado a la Universidad Icesi en el Suroccidente Colombiano, entre los años 2012 a 2017. Resultados: Se identificaron 44 pacientes con candidiasis invasiva, 27 de ellos mujeres (61%). La mediana de edad fue de 56 años (36 – 70). Más del 50% tenían una enfermedad crónica subyacente, uso de antibióticos (84%), catéter venoso central (80%), ventilación mecánica (68%) y nutrición enteral (66%) El 80% requirió manejo en unidad de cuidados intensivos (UCI) donde debutaron con sepsis (68%) y falla respiratoria (61%). En el 90% de los casos se aisló alguna especie de Candida spp. A partir de hemocultivo y sólo al 22% se le realizó prueba de sensibilidad. El tratamiento de elección fue con fluconazol (80%), asociado a caspofungina (70%). La tasa de mortalidad fue del 49%, con una mediana de 33 (22-49,5) días desde el ingreso hasta el fallecimiento. C. albicans fue el principal microorganismo aislado. La resistencia a azoles en especies no albicans existe en nuestro medio. Conclusión: La candidiasis se presenta como candidemia asociada a infección bacteriana concomitante, que cobra mayor importancia en el contexto del paciente inmunosuprimido asociado a elevadas tasas de mortalidad.

New and Promising Chemotherapeutics for Emerging Infections Involving Drug-resistant Non-albicans Candida Species

Fungal infections are a veritable public health problem worldwide. The increasing number of patient populations at risk (e.g. transplanted individuals, cancer patients, and HIV-infected people), as well as the use of antifungal agents for prophylaxis in medicine, have favored the emergence of previously rare or newly identified fungal species. Indeed, novel antifungal resistance patterns have been observed, including environmental sources and the emergence of simultaneous resistance to different antifungal classes, especially in Candida spp., which are known for the multidrug-resistance (MDR) profile. In order to circumvent this alarming scenario, the international researchers' community is engaged in discovering new, potent, and promising compounds to be used in a near future to treat resistant fungal infections in hospital settings on a global scale. In this context, many compounds with antifungal action from both natural and synthetic sources are currently under clinical development, including those that target either ergosterol or β(1,3)-D-glucan, presenting clear evidence of pharmacologic/pharmacokinetic advantages over currently available drugs against these two well-known fungal target structures. Among these are the tetrazoles VT-1129, VT-1161, and VT-1598, the echinocandin CD101, and the glucan synthase inhibitor SCY-078. In this review, we compiled the most recent antifungal compounds that are currently in clinical trials of development and described the potential outcomes against emerging and rare Candida species, with a focus on C. auris, C. dubliniensis, C. glabrata, C. guilliermondii, C. haemulonii, and C. rugosa. In addition to possibly overcoming the limitations of currently available antifungals, new investigational chemical agents that can enhance the classic antifungal activity, thereby reversing previously resistant phenotypes, were also highlighted. While novel and increasingly MDR non-albicans Candida species continue to emerge worldwide, novel strategies for rapid identification and treatment are needed to combat these life-threatening opportunistic fungal infections.

A prospective, multi-center study of Candida bloodstream infections in Chile

BACKGROUND

Active surveillance is necessary for improving the management and outcome of patients with candidemia. The aim of this study was to describe epidemiologic and clinical features of candidemia in children and adults in tertiary level hospitals in Chile.

METHODS

We conducted a prospective, multicenter, laboratory-based survey study of candidemia in 26 tertiary care hospitals in Chile, from January 2013 to October 2017.

RESULTS

A total of 780 episodes of candidemia were included, with a median incidence of 0.47/1,000 admissions. Demographic, clinical and microbiological information of 384 cases of candidemia, from 18 hospitals (7,416 beds), was included in this report. One hundred and thirty-four episodes (35%) occurred in pediatric patients and 250 (65%) in adult population. Candida albicans (39%), Candida parapsilosis (30%) and Candida glabrata (10%) were the leading species, with a significant difference in the distribution of species between ages. The use of central venous catheter and antibiotics were the most frequent risk factors in all age groups (> 70%). Three hundred and fifteen strains were studied for antifungal susceptibility; 21 strains (6.6%) were resistant to fluconazole, itraconazole, voriconazole, anidulafungin or micafungin. The most commonly used antifungal therapies were fluconazole (39%) and echinocandins (36%). The overall 30-day survival was 74.2%, significantly higher in infants (82%) and children (86%) compared with neonates (72%), adults (71%) and elderly (70%).

CONCLUSIONS

Our prospective, multicenter surveillance study showed a low incidence of candidemia in Chile, with high 30-day survival, a large proportion of elderly patients, C. glabrata as the third most commonly identified strain, a 6.6% resistance to antifungal agents and a frequent use of echinocandins.

Antifungal effects of the flavonoids kaempferol and quercetin: a possible alternative for the control of fungal biofilms

This study aimed to determine the minimum inhibitory concentration (MIC) of kaempferol and quercetin against planktonic and biofilm forms of the Candida parapsilosis complex. Initially, nine C. parapsilosis sensu stricto, nine C. orthopsilosis and nine C. metapsilosis strains were used. Planktonic susceptibility to kaempferol and quercetin was assessed. Growing and mature biofilms were then exposed to the flavonoids at MIC or 10xMIC, respectively, and theywere also analyzed by confocal laser scanning microscopy. The MIC ranges were 32-128 µg ml^-1 for kaempferol and 0.5-16 µg ml^-1 for quercetin. Kaempferol and quercetin decreased (P < 0.05) the metabolic activity and biomass of growing biofilms of the C. parapsilosis complex. As for mature biofilms, the metabolic effects of the flavonoids varied, according to the cryptic species, but kaempferol caused an overall reduction in biofilm biomass. Microscopic analyses showed restructuring of biofilms after flavonoid exposure. These results highlight the potential use of these compounds as sustainable resources for the control of fungal biofilms.

Echinocandin-Induced Microevolution of Candida parapsilosis Influences Virulence and Abiotic Stress Tolerance

Candida species are a major cause of life-threatening bloodstream infections worldwide. Although Candida albicans is responsible for the vast majority of infections, the clinical relevance of other Candida species has also emerged over the last twenty years. This shift might be due in part to changes in clinical guidelines, as echinocandins became the first line of therapeutics for the treatment. Candida parapsilosis is an emerging non-albicans Candida species that exhibits lower susceptibility levels to these drugs. Candida species frequently display resistance to echinocandins, and the mechanism for this is well-known in C. albicans and Candida glabrata, where it is mediated by amino acid substitutions at defined locations of the β-1,3-glucan synthase, Fks1p. In C. parapsilosis isolates, Fks1p harbors an intrinsic amino acid change at position 660 of the hot spot 1 (HS1) region, which is thought to be responsible for the high MIC values. Less is known about acquired substitutions in this species. In this study, we used directed evolution experiments to generate C. parapsilosis strains with acquired resistance to caspofungin, anidulafungin, and micafungin. We showed that cross-resistance was dependent on the type of echinocandin used to generate the evolved strains. During their characterization, all mutant strains showed attenuated virulence in vivo and also displayed alterations in the exposure of inner cell wall components. The evolved strains harbored 251 amino acid changes, including three in the HS1, HS2, and HS3 regions of Fks1p. Altogether, our results demonstrate a direct connection between acquired antifungal resistance and virulence of C. parapsilosisIMPORTANCECandida parapsilosis is an opportunistic fungal pathogen with the ability to cause infections in immunocompromised patients. Echinocandins are the currently recommended first line of treatment for all Candida species. Resistance of Candida albicans to this drug type is well characterized. C. parapsilosis strains have the lowest in vitro susceptibility to echinocandins; however, patients with such infections typically respond well to echinocandin therapy. There is little knowledge of acquired resistance in C. parapsilosis and its consequences on other characteristics such as virulence properties. In this study, we aimed to dissect how acquired echinocandin resistance influences the pathogenicity of C. parapsilosis and to develop explanations for why echinocandins are clinically effective in the setting of acquired resistance.