Prévalence de Candida parapsilosis, C. orthopsilosis et de C. metapsilosis au sein des candidémies au CHU de Nantes et profil de sensibilité aux échinocandines par la méthode E-test : étude rétrospective de cinq ans (2004-2009)

Aim of the study

To determine the prevalence of C. parapsilosis sensu stricto, C. orthopsilosis and C. metapsilosis among candidemia at Nantes University Hospital and to evaluate the in vitro susceptibility of the isolates against three echinocandin drugs (caspofungin, micafungin and anidulafungin).

Material and methods

Retrospective study (march 2004 to july 2009) of 178 cases of candidemia corresponding to 183 Candida spp. strains identified by means of routine phenotypical methods. Re-identification of C. parapsilosis sensu lato isolates was performed by ITS rDNA sequencing analysis. Minimal inhibitory concentrations (MIC) were determined by E-test^®. All echinocandin non-susceptible isolates (MIC > 2 μg/mL) were analyzed for the presence/absence of FKS1 mutations associated with resistance.

Results

During this period, C. parapsilosis sensu lato was responsible for 27 candidemia, ranging at the second most common Candida species after C. albicans (n = 99, 54.1%). Neither isolates belong to C. orthopsilosis nor C. metapsilosis. According to the literature, all the isolates displayed high MICs against the three echinocandin drugs. All the isolates displayed both susceptibility (MIC ≤ 2 μg/mL) and a good agreement between MICs read at 24 h and 48 h for caspofungin and micafungin (MIC₅₀ = 0.75 μg/mL, MIC₉₀ = 1.5 μg/mL). Surprisingly, whereas most of the strains were susceptible to anidulafungin at 24 h (MIC₅₀ = 1 μg/mL, MIC₉₀ = 1.5 μg/mL), 14 (52 %) displayed non-susceptibility, despite the lack of mutation associated with resistance on FKS1, when reading was performed at 48 h (MIC₅₀ = 3 μg/mL, MIC₉₀ = 12 μg/mL).

Conclusion

Prevalence of C. orthopsilosis and C. metapsilosis in patients with candidemia is low at Nantes University Hospital. The difficulty encountered with MIC reading by E-test^® are discussed.     

Characterization of <Emphasis Type="Italic">Candida parapsilosis</Emphasis> complex strains isolated from invasive fungal infections

In the present work, we studied the distribution of Candida parapsilosis complex species and the antifungal susceptibility of clinical isolates collected during an Italian surveillance study of yeast invasive fungal infections (IFIs) in intensive care units (ICUs). Minimum inhibitory concentrations (MICs) were determined using the Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution method. BanI digestion patterns of the secondary alcohol dehydrogenase polymerase chain reaction (PCR) products were used to identify C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis. A total of 138 C. parapsilosis isolates were stored (January 2007–December 2008). The overall frequency of C. parapsilosis complex in IFIs was 22%. Of the 138 tested isolates, 95% were C. parapsilosis sensu stricto, 3.6% were C. orthopsilosis, and 1.4% were C. metapsilosis. The MIC₅₀ values (expressed as μg/ml) for anidulafungin, caspofungin, and micafungin for C. parapsilosis complex were 2, 1, and 2, respectively, and the MIC₉₀ values were 4, 2, and 4, respectively. The MIC₅₀ and MIC₉₀ values for itraconazole and posaconazole were 0.12 and 0.25, respectively, and for fluconazole, they were 1 and 4, respectively. This study, the most comprehensive study conducted to date to evaluate the frequency and antifungal susceptibility profiles of C. parapsilosis complex isolates from critically ill patients in Italy, highlights the low prevalence of C. orthopsilosis and C. metapsilosis in IFIs.     

Comparison of biofilm-producing ability of clinical isolates of Candida parapsilosis species complex

ObjectiveCandida parapsilosis is one of the main emerging non-Candida albicans species leading to superficial and systemic fungal infections in humans. Candida has the ability to produce biofilms associated with pathogenesis. The aim of the study was to estimate biofilm-producing ability of clinical isolates of C. parapsilosis sp. complex.MethodsClinical samples of C. parapsilosis complex have been analyzed. Crystal violet (CV) staining and tetrazolium reduction assay (MTT) have been used to analyze the clinical isolates ability to produce biofilms. The biofilm's structural characteristics have been assessed by using scanning electron microscopy.ResultsAll 65 isolates were able to form biofilm. In addition, no significant difference was found between biofilm quantification based on two assays at different time intervals (24 h, 48 h, 72 h, 96 h) (P > 0.05), with the exception of Candida orthopsilosis, which exhibited higher metabolic activity at 24 h time point (P < 0.05). Moreover, metabolic activity and production of biofilm biomass demonstrated statistically significant correlation (r = 0.685, P < 0.01). According to microscopic observations, the investigated clinical strains formed the similar surface topography with the slight differences in morphology; in addition, there was no statistically significant difference between efficiency of two assays to quantify biofilm.ConclusionIt was shown that, similar to C. parapsilosis sensu stricto, two cryptic identified species (C. orthopsilosis and Candida metapsilosis) obtained from different clinical samples, were biofilm producers, while C. parapsilosis sensu stricto exhibited the highest biofilm production.     

Epidemiology and reporting of candidaemia in Belgium: a multi-centre study

The primary aim of this study was to collect national epidemiological data on candidaemia and to determine the reporting time of species identification and antifungal susceptibility in clinical practice. During a 1-year period (March 2013 until February 2014), every first Candida isolate from each episode of candidaemia was included prospectively from 30 Belgian hospitals. Identification and susceptibility testing were performed according to local procedures and isolates were sent to the National Reference Center for Mycosis. Species identification was checked by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and internal transcribed spacer (ITS) sequencing in case no reliable identification was obtained by MALDI-TOF MS. Antifungal susceptibility testing was performed according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodology. A total of 355 isolates were retrieved from 338 patients. The mean incidence rate of candidaemia was 0.44 (range: 0.07 to 1.43) per 1000 admissions or 0.65 (range: 0.11 to 2.00) per 10,000 patient days. Candida albicans was most frequently found (50.4 %), followed by C. glabrata (27.3 %) and C. parapsilosis sensu lato (9.8 %). The overall resistance to fluconazole was 7.6 %, ranging from 3.9 % in C. albicans to 20.0 % in C. tropicalis. Only one C. glabrata isolate was resistant to the echinocandins. Four days after blood culture positivity, 99.7 % of the identifications and 90.3 % of the antifungal profiles were reported to the treating clinician. Candidaemia incidence rates differed up to 20-fold among Belgian hospitals; no clear factors explaining this difference were identified. The overall antifungal resistance rates were low but high azole resistance rates were recorded in C. tropicalis.     

Candidemia in a Portuguese tertiary care hospital: Analysis of a 2-year period

BackgroundCandidemia is a nosocomial infection of increasing importance, associated with high morbidity and mortality. The aim of this study is to describe the species distribution, risk factors, management and outcomes of patients with candidemia.MethodsWe conducted a retrospective study at Centro Hospitalar Universitário de São João, Portugal, between January 2016 and December 2017.ResultsA total of 117 candidemia episodes (n = 114 patients) were included. Median age was 65 years, with an increased prevalence of older ages. Candida albicans (51.3%) was the most prevalent species, followed by C. glabrata (22.2%), C. parapsilosis (15.4%), C. tropicalis (4.3%) and C. lusitaniae (2.6%). Forty-two patients (35.9%) did not receive antifungal drugs after diagnosis of candidemia. Echinocandins were used as first-line drug therapy in half of the treated patients (50.7%). The median EQUAL Candida Score was 6/17 (IQR 6-9) for patients without central venous catheter (CVC) and 11/20 (IQR 6-14) for patients with CVC. The 30 days-mortality was 31,6% and was not significantly associated with the timing of antifungal therapy and the EQUAL Candida Score.ConclusionThe distribution of Candida species has changed in recent years, with an increase in the proportion of C. albicans and C. glabrata. Rapid diagnostic tests, empiric antifungal therapy and source control are essential to improve the prognosis of patients with candidemia. More multicentric prospective studies are needed to evaluate the association of mortality with the timing of antifungal therapy or the EQUAL Candida Score.     

Azole resistance survey on clinical Aspergillus fumigatus isolates in Spain

ObjectivesWe aimed to assess the percentage of azole resistance in Aspergillus fumigatus in Spain.MethodsThirty participating Spanish hospitals stored all morphologically identified A. fumigatus sensu lato clinical isolates—regardless their clinical significance—from 15 February to 14 May 2019. Isolates showing azole resistance according to the EUCAST 9.3.2 methodology were molecularly identified and the cyp51A gene was studied in A. fumigatus sensu stricto isolates.ResultsEight hundred and forty-seven isolates from 725 patients were collected in 29 hospitals (A. fumigatus sensu stricto (n = 828) and cryptic species (n = 19)). Isolates were mostly from the lower respiratory tract (94.0%; 797/847). Only cryptic species were amphotericin B resistant. Sixty-three (7.4%) out of the 847 isolates were resistant to ≥1 azole(s). Azole resistance was higher in cryptic species than in A. fumigatus sensu stricto (95%, 18/19 vs. 5.5%, 45/828); isavuconazole was associated to the lowest number of non-wild type isolates. The dominant mechanism of resistance was the presence of TR₃₄-L98H substitutions (n = 24 out of 63). Out of the 725 patients, 48 (6.6%) carried either cryptic species (n = 14) or A. fumigatus sensu stricto (n = 34; 4.7%) resistant isolates. Aspergillus fumigatus sensu stricto harbouring either the TR₃₄-L98H (n = 19) or TR₄₆/Y121F/T289A (n = 1) mutations were detected in patients in hospitals located at 7/24 studied cities.DiscussionOf the patients, 6.6% carry azole-resistant A. fumigatus sensu lato isolates in Spain. TR₃₄-L98H is the dominant cyp51A gene substitutions, although its presence is not widespread.     

Molecular identification,phylogenetic analysis and antifungal susceptibility patterns of Aspergillus nidulans complex and Aspergillus terreus complex isolated from clinical specimens

ObjectiveAspergillus sections Terrei and Nidulantes are the less common causes of invasive aspergillosis and pulmonary aspergillosis (PA) in immunocompromised patients when compared to A. fumigatus and A. flavus. Identifying these fungi as the infectious agent is crucial because of the resistance to amphotericin B (AMB) and increased lethality. The aim of this study was to identify the molecular status, evaluate the genetic diversity and examine the antifungal susceptibility profile of the uncommon Aspergillus species. Forty-five uncommon Aspergillus species were identified based on the microscopic and macroscopic criteria. Then, the molecular identification was performed using the sequencing beta tubulin (benA) gene. In vitro antifungal susceptibility to amphotericin B (AMB), itraconazole (ITC), ravuconazole (RAV), voriconazole (VRC), caspofungin (CFG) isavuconazole (ISA) and posaconazole (POS) test was performed according to the CLSI M38-A2 guidelines.ResultsA. terreus was the most species detected, followed by A. nidulans, A. latus, A. ochraceus, and A. citrinoterreus, respectively. The analysis of the benA gene showed the presence of 12 distinct genotypes among the A. terreus isolates. The other species did not show any intraspecies variation. CFG exhibited the lowest MEC₅₀/MIC₅₀ (0.007 μg/mL), followed by POS (0.125 μg/mL), VRC, ITC, ISA (0.25 μg/mL), RAV (0.5 μg/mL), and AMB (8 μg/mL). Among all the isolates, only 15.5% (7/45) were susceptible to AMB.ConclusionAntifungal susceptibility pattern of the uncommon Aspergillus species is useful to improve patient management and increase knowledge concerning the local epidemiology. Moreover, this information is necessary when an outbreak dealing with drug-resistant infections occurs.     

Identification and Differentiation of Candida parapsilosis Complex Species by Use of Exon-Primed Intron-Crossing PCR

The Candida parapsilosis complex is composed of Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, and the closely related species Lodderomyces elongisporus. An exon-primed intron-crossing PCR assay was developed here to distinguish the members of the species complex on the basis of the distinct sizes of amplicons, and Candida orthopsilosis and Candida metapsilosis were further discriminated by restriction enzyme analysis.     

Emergence of Candida parapsilosis candidemia at Cochin hospital. Characterization of isolates and search for risk factors

Candida parapsilosis is a normal saprophyte of the skin, characterized by their affinity for catheters. This species has, in vitro, a level of sensitivity against the echinocandins, significantly lower than that observed with other Candida species. Recently, new species: Candida orthopsilosis and Candida metapsilosis, phenotypically identical to C. parapislosis, have been identified by molecular biology. From 2003 to 2007, in the Cochin hospital, the proportion of C. parapsilosis among non-albicans species isolated from blood cultures increased from 17 (3/18) to 38% (5/13). To understand the reasons for this emergence, we retrospectively characterized isolates, conducted a case-control and researched a link between the emergence and introduction of caspofungin in our hospital. We analysed data from 26 patients who had candidemia with C. parapsilosis. Genotypic analysis of isolates has not identified the new species C. orthopsilosis and C. metapsilosis. The case-control study showed a broad-spectrum antibiotics was significantly more frequent for candidemia with C. parapsilosis compared to C. albicans (52 versus 26%, P = 0.04) as a previous treatment with caspofungin (11 versus 0%, P = 0.04). The introduction of caspofungin is contemporary with the emergence of candidemia with C. parapsilosis with a tendency to be related to its level of consumption in the ICU. Our results should encourage biologists to closely monitor the frequency and level of sensitivity of strains of C. parapsilosis isolated in hospital.     

Resistance of Candida to azoles and echinocandins worldwide

BackgroundRecently there has been an increase in Candida infections worldwide. A handful of species in the genus Candida are opportunistic pathogens and have been known to cause infections in immunocompromised or otherwise impaired hosts. These infections can be superficial, affecting the skin or mucous membrane, or invasive, which can be life-threatening. Azoles and echinocandins are antifungal drugs used globally to treat Candida infections. However, resistance to these antifungal drugs has increased in many of the Candida species, and the effects this has in the clinical setting can be seen.ObjectivesHere, we discuss the mechanisms that Candida albicans, Candida dubliniensis, Candida glabrata, Candida parapsilosis, Candida tropicalis and Candida auris are implementing to increase resistance to azoles and echinocandins, and how they are affecting clinical, or hospital, settings worldwide.SourcesDifferent studies and papers describing the mechanisms of antifungal drugs and Candida species evolution to becoming resistant to these drugs were looked at for this review.ContentWe discuss the mechanisms that azoles and echinocandins use against Candida species to treat infections, as well as the evolution of these fungi to become resistant to these drugs, and the effect this has in the clinical settings around the globe.ImplicationsIncreased resistance to azoles and echinocandins by Candida species is an increasingly serious problem in clinical settings worldwide. Understanding the mechanisms used against antifungal drugs is imperative for patient treatment.     

Comparative in vitro activities of seven antifungal drugs against clinical isolates of Candida parapsilosis complex

ObjectiveCandida parapsilosis species complex, an important set of non-albicans Candida species, is known to cause candidaemia particularly in neonates and infants. However, the incidence has increased in recent years, owing to higher numbers of at individuals at risk for these infections. Our objective was to evaluate the in vitro susceptibility of clinical isolates of C. parapsilosis complex isolates from Iran to seven antifungal drugs.Material and methodsOne hundred-one clinical isolates of C. parapsilosis species complex cultured from humans were included. Species identification had been previously confirmed by combined phenotypic characteristics, matrix-assisted laser desorption ionization-time of flight mass spectrometry-based assay and reconfirmed by DNA sequence analysis of the ITS rDNA region and D1/D2 gene. Minimum inhibitory concentrations (MICs) for amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, micafungin and anidulafungin were determined against well-characterized isolates by broth microdilution susceptibility testing according to the CLSI M27-A3 guideline.ResultsSpecies identifications were performed on 101 isolates, of which 88 (87.2%) C. parapsilosis sensu stricto and 13 (12.8%) C. orthopsilosis. Amphotericin B and posaconazole were the most active drugs with 100% of isolates being wild-type (WT). Voriconazole and micafungin, 99% of isolates were WT. The low activity was recorded for fluconazole and itraconazole with 93.1% and 89.1% of isolates being WT, respectively. At the species level, all Candida parapsilosis sensu stricto isolates were WT to amphotericin B and posaconazole and all Candida orthopsilosis isolates were WT to amphotericin B, voriconazole, posaconazole, anidulafungin and micafungin. In contrast, the highest rate of non-WT was observed in C. orthopsilosis to itraconazole (4 of 13, 30.8%).ConclusionsAlthough almost all of the tested drugs demonstrated potent activity against C. parapsilosis species complex, it seems that more especially C. orthopsilosis isolates had decreased susceptibility to itraconazole. Further studies are needed to determine how these findings may switch into in vivo efficacy.     

Characterization of Candida parapsilosis complex isolates

Candida parapsilosis former groups II and III have recently been established as independent species, named Candida orthopsilosis and Candida metapsilosis, respectively. We investigated the distribution of C. parapsilosis complex species in 122 isolates from blood and other sources in a southern Spain tertiary-care hospital, and we examined the relationship between species, site of isolation and biofilm positivity. We also evaluated the planktonic MICs and sessile MICs (SMICs) of voriconazole, amphotericin B and anidulafungin. One hundred and eleven isolates (91%) were categorized as C. parapsilosis sensu stricto, whereas ten isolates (8.2%) were categorized as C. orthopsilosis and one (0.8%) as C. metapsilosis. Biofilm positivity was observed in 58.5% (65 of 111) of C. parapsilosis sensu stricto isolates vs. 0% (0 of 11) of C. orthopsilosis and C. metapsilosis isolates (p <0.01). There was no difference in biofilm production among C. parapsilosis sensu stricto isolates from blood and other sources. MIC values showed that all isolates were susceptible to voriconazole and amphotericin B, whereas two isolates (1.8%) of C. parapsilosis sensu stricto were non-susceptible to anidulafungin. However, the MIC₉₀ value of voriconazole was higher (0.125 mg/L) for C. orthopsilosis than for C. parapsilosis sensu stricto (0.03 mg/L). In contrast to planktonic cells, the SMICs show that amphotericin B and anidulafungin are moderately effective against the biofilm of C. parapsilosis sensu stricto, whereas voriconazole is ineffective.     

Fungemia in the French department of Mayotte,Indian Ocean: A 10 years survey

ObjectiveThis study aimed at providing original data on fungemia in the Centre Hospitalier de Mayotte in terms of prevalence, epidemiological characteristics of infected patients, yeast species distribution and profile of in vitro antifungals susceptibility.MethodsA total of 223 positive blood cultures for yeasts were retrospectively reported during the period April 2010–April 2020.ResultsNinety-five episodes were identified corresponding to an incidence rate of 3.7 cases/100,000 inhabitants. The average age of patients was 33.5 years, and 63.3% patients were hospitalized in intensive care unit. The main co-morbidities were surgery in the 30 days prior to fungemia (27.8%), neoplasia (22.8%), parenteral nutrition (17.7%), diabetes (16.5%) and immunosuppressive medications (31.6%). Candida spp accounted for the majority of isolates (92.4%) with a predominance of non-albicans species (55.8% vs 33.7%), including C. albicans (33.7%), C. tropicalis (30.5%) and C. parapsilosis (20%). The antifungal susceptibility profiles did not differ from expected results for each species and did not change significantly over time.DiscussionFungemia remain frequent hospital infections associated with high mortality in Mayotte. The vast majority of fungemia was due to Candida spp. Non-albicans Candida species reach half of the Candida isolates with a high percentage of C. tropicalis. Surprisingly, no case of candidemia due to C. glabrata were identified. The management of candidemia remains satisfactory and the treatment was adapted according to the international recommendations. However, the high susceptibility of Candida spp. isolates to fluconazole may invite to reconsider the use of this molecule as empirical and first-line treatment of candidemia in Mayotte.     

Prevalence and species distribution of microorganisms isolated among non-pregnant women affected by vulvovaginal candidiasis: A retrospective study over a 20 year-period

BackgroundVulvovaginal candidiasis (VVC) is the second most common infection of the genital tract affecting millions of women worldwide. Data concerning the distribution and antifungal resistance of Candida species responsible of VVC vary among countries and population studied. Objectives: The aim of this work was to determine the prevalence, species distribution and antifungal susceptibility patterns of Candida species among symptomatic women over a 20-year period.MethodsA total of 5,820 unique samples were retrospectively identified. Out of them, 1,046 (18%) were diagnosed with VVC.ResultsWomen between 18 and 30 years had the highest prevalence rate of VVC (21%). Women aged less than 18 years and greater than 51 years had the highest prevalence rates of vaginal bacterial infections. Thirty-five (3.3%) women presented recurrent VVC. The most common yeast isolated was C. albicans, followed by C. glabrata, C. krusei, and C. parapsilosis. Non-Candida albicans species (NAC) were more significantly isolated among women aged 51 or above, than in women included in other groups (p < 0.01). Resistance to fluconazole and amphotericin B was infrequent in C. albicans strains. Resistance to fluconazole and amphotericin B was infrequent in C. albicans strains. NAC species presented higher resistance rates against fluconazole (30%) and voriconazole (25%). C. krusei and C. glabrata isolates showed lower MICs than most of the strains against amphotericin B (1 mg/L) and flucytosine (1 mg/L).ConclusionsOur findings indicated that continued surveillance on Candida species distribution and non-susceptibility rates to antifungals should be routinely reported to help the selection of the most appropriate drug, to avoid the emergence of resistant strains, and to improve the patient's outcomes.     

Current Epidemiology of Candida Infection

Candidemia and candidiasis are among the most frequent healthcare care-associated infections and lead to significant morbidity and mortality. The predominant species causing candidemia remains Candida albicans, but it has declined from the majority species to causing less than 50% of U.S. cases. Increasing proportions of infections are being caused by C. glabrata, which now causes almost 30% of U.S. cases, as well as C. parapsilosis and other non-C. albicans species. Outside the United States, the predominant species is dependent upon the region. Pediatric candidemia rates are declining in the U.S., but the cause of this decline has not been fully elucidated. While overall resistance to antifungal agents has remained low among Candida species, there is some concern for echinocandin resistance, as well as multidrug resistance, in C. glabrata. Although some aspects of candidemia and candidiasis have remained constant, rates, species, and susceptibility are in a constant state of flux.     

High colonization by Candida parapsilosis sensu stricto on hands and surfaces in an adult intensive care unit

BackgroundYeasts of the Candida parapsilosis complex have frequently been reported as agents of fungal infection in Brazil and worldwide, most of the cases are related to hospital-acquired infection. C. parapsilosis is the third most common cause of candidemia, and the hands of hospital workers as well as hospital surfaces have been suggested as possible sources.ObjectivesIn this study we verified the frequency of C. parapsilosis on the hands of workers and on surfaces in the adult intensive care unit (AICU) of a tertiary hospital in Paraná-Brazil.MethodsSurface samples were collected with swabs moistened with saline, and a plastic bag with distilled water was used to collect samples from hands. The yeasts were identified by morphology, MALDI-TOF mass spectrometry and PCR-RFLP of the secondary alcohol dehydrogenase-encoding gene (SADH) after digestion with the restriction enzyme BanI.Results and conclusionsA total of 223 yeast were found, of which 101 (45.29%) were identified as C. parapsilosis sensu stricto. Of these, 46.66% (n = 35) were found on surfaces and 44.59% (n = 66) on the hands of the employees. The analysis of C. parapsilosis strains by microsatellite loci (CP1, CP4, CP6 and B5) showed 80 different genotypes. Their antifungal susceptibility profile, evaluated by the microdilution broth method, revealed that C. parapsilosis was sensitive to amphotericin B, fluconazole and voriconazole, but not to micafungin. The results revealed the heterogeneity of the yeast population, suggesting that there is no common source of contamination in the AICU of this hospital.     

Candidemia in a Tertiary Care Hospital: Epidemiology and Factors Influencing Mortality

The present study was conducted in order to assess the epidemiology and clinical course of candidemia and to identify the risk factors associated with mortality. A total of 143 episodes of nosocomial candidemia were identified during a 5-year period, and these were included in the study. The majority of candidemic episodes were due to Candida albicans (63, 44%), followed by Candida parapsilosis (32, 22%). The overall mortality was 45%. The following independent prognostic factors for mortality were identified: bacterial sepsis, rapidly fatal illness, chronic obstructive lung disease, presence of a central venous catheter, candidemia due to Candida albicans, and lack of antifungal therapy. Electronic Publication     

Levels of beta-D-glucan in Candida auris supernatants,an in vitro and in vivo preliminary study

ObjectivesSerum (1,3)-beta-d-glucan (BDG) assay is a non–culture-based test recommended for the diagnosis of invasive candidiasis owing to its faster results and higher sensitivity than blood cultures. Its performance might vary for different Candida species. The aim of this study was to determine in vitro levels of BDG in Candida auris culture supernatants and evaluate BDG levels in patients with C. auris candidemia sustained by these stains.MethodsC. auris strains were collected from blood cultures of patients who had a concomitant (–24 to +72 hours) serum BDG test (Fungitell assay). Supernatants of broth media culture of C. auris strains and two Candida albicans (controls) strains were prepared and tested for BDG.ResultsTen C auris strains were included. Supernatants of two C. albicans considered as controls had a mean BDG level of 1155 pg/mL (considered 100% reactivity). The median BDG level in supernatants of C. auris strains was 275 pg/mL (IQR 165–523 pg/mL), with a median reactivity of 24% (range 6%–72%). In vivo, the median BDG level was 129 pg/mL (IQR, 28–199 pg/mL). Sensitivity of BDG for C. auris candidemia was 60%. All patients received antifungal treatment with an echinocandin initiated a median of 2 days (IQR –8 to 0) before blood collection for BDG.DiscussionOur C. auris strains released lower amounts of BDG when compared to C. albicans. Clinical implications include lower sensitivity of serum BDG for the diagnosis of C. auris candidemia with a consequent impact on management protocols in settings with high prevalence of this species.     

Antifungal susceptibility profile of Candida clinical isolates from 22 hospitals of São Paulo State,Brazil

This study aimed to evaluate the frequency of cryptic Candida species from candidemia cases in 22 public hospitals in São Paulo State, Brazil, and their antifungal susceptibility profiles. During 2017 and 2018, 144 isolates were molecularly identified as 14 species; C. parapsilosis (32.6%), C. albicans (27.7%), C. tropicalis (14.6%), C. glabrata (9.7%), C. krusei (2.8%), C. orthopsilosis (2.8%), C. haemulonii var. vulnera (2.1%), C. haemulonii (1.4%), C. metapsilosis (1.4%), C. dubliniensis (1.4%), C. guilliermondii (1.4%), C. duobushaemulonii (0.7%), C. kefyr (0.7%), and C. pelliculosa (0.7%). Poor susceptibility to fluconazole was identified in 6.4% of C. parapsilosis isolates (0.12 to >64 µg/mL), 50% of C. guilliermondii (64 µg/mL), 66.6% of C. haemulonii var. vulnera (16-32 µg/mL), and C. duobushaemulonii strain (MIC 64 µg/mL). Our results corroborated the emergence of C. glabrata in Brazilian cases of candidemia as previously reported. Importantly, we observed a large proportion of non-wild type C. glabrata isolates to voriconazole (28.6%; <0.015 to 4 µg/mL) all of which were also resistant to fluconazole (28.6%). Of note, C. haemulonii, a multidrug resistant species, has emerged in the Southeast region of Brazil. Our findings suggested a possible epidemiologic change in the region with an increase in fluconazole-resistant species causing candidemia. We stress the relevance of routine accurate identification to properly manage therapy and monitor epidemiologic trends.     

Accuracy of Sensititre YeastOne echinocandins epidemiological cut-off values for identification of FKS mutant Candida albicans and Candida glabrata: a ten year national survey of the Fungal Infection Network of Switzerland (FUNGINOS)

ObjectivesEchinocandins represent the first-line treatment of candidaemia. Acquired echinocandin resistance is mainly observed among Candida albicans and Candida glabrata and is associated with FKS hotspot mutations. The commercial Sensititre YeastOne™ (SYO) kit is widely used for antifungal susceptibility testing, but interpretive clinical breakpoints are not well defined. We determined echinocandins epidemiological cut-off values (ECV) for C. albicans/glabrata tested by SYO and assessed their ability to identify FKS mutants in a national survey of candidaemia.MethodsBloodstream isolates of C. albicans and C. glabrata were collected in 25 Swiss hospitals from 2004 to 2013 and tested by SYO. FKS hotspot sequencing was performed for isolates with an MIC≥ECV for any echinocandin.ResultsIn all, 1277 C. albicans and 347 C. glabrata were included. ECV 97.5% of caspofungin, anidulafungin and micafungin were 0.12, 0.06 and 0.03 μg/mL for C. albicans, and 0.25, 0.12 and 0.03 μg/mL for C. glabrata, respectively. FKS hotspot sequencing was performed for 70 isolates. No mutation was found in the 52 ‘limit wild-type’ isolates (MIC=ECV for at least one echinocandin). Among the 18 ‘non-wild-type’ isolates (MIC>ECV for at least one echinocandin), FKS mutations were recovered in the only two isolates with MIC>ECV for all three echinocandins, but not in those exhibiting a ‘non-wild-type’ phenotype for only one or two echinocandins.ConclusionThis 10-year nationwide survey showed that the rate of echinocandin resistance among C. albicans and C. glabrata remains low in Switzerland despite increased echinocandin use. SYO-ECV could discriminate FKS mutants from wild-type isolates tested by SYO in this population.