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Whole genome sequencing has been extensively used to describe infection outbreaks, although with limited application on Candida albicans and Candida parapsilosis.We retrospectively studied all patients admitted to the neonatal care unit diagnosed with candidemia caused by C. albicans (n = 46) or C. parapsilosis (n = 31) between 2007 and 2010 (Period 1) and 2011 and 2014 (Period 2). All isolates were genotyped by microsatellite markers. A cluster was defined as a group of ≥ 2 patients infected by strains with identical genotypes. For the validation of microsatellite markers and outbreak investigation, phylogenetic analyses and whole genome pairwise strain comparisons were performed.The number of episodes was significantly higher in Period 1 than in Period 2 (51 vs 32; P = 0.003); the reduction in the number of cases coincided with the educational campaign for catheter care implementation in 2011. Overall, eight genotypes were clusters involving 29 patients. All C. albicans (n = 5) and C. parapsilosis (n = 3) clusters were found during Period 1 before the educational campaign. No statistically significant differences were found between the percentage of C. albicans and C. parapsilosis clusters, but the percentage of patients associated to the clusters was significantly higher for C. parapsilosis clusters in comparison to C. albicans clusters (52 vs 28.2%; P = 0.03). Whole genome sequencing confirmed microsatellite-defined clusters with high bootstrap values.Whole genome sequences confirmed microsatellite-defined clusters, corroborating the presence of outbreaks. Persistent or sporadic Candida clusters causing candidemia in neonates disappeared after the implementation of catheter care educational campaigns., Lay Summary: We retrospectively studied all patients admitted to the neonatal care unit diagnosed with candidemia caused by C. albicans or C. parapsilosis. Reliable whole genome sequences confirmed microsatellite-defined clusters, corroborating the presence of outbreaks before educational campaigns for catheter care., (© The Author(s) 2021. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)

Objectives: Emergence of azole resistance may contribute to recurrences of vulvovaginal candidiasis. Thus, new drugs are needed to improve the therapeutic options. We studied the in vitro activity of ibrexafungerp and comparators against Candida albicans isolates from vaginal samples and blood cultures. Furthermore, isolates were genotyped to study compartmentalization of genotypes and the relationship between genotype and antifungal susceptibility., Methods: Candida albicans unique patient isolates (n = 144) from patients with clinical suspicion of vulvovaginal candidiasis (n = 72 isolates) and from patients with candidaemia (n = 72) were studied. Antifungal susceptibility to amphotericin B, fluconazole, voriconazole, posaconazole, isavuconazole, clotrimazole, miconazole, micafungin, anidulafungin and ibrexafungerp was tested (EUCAST 7.3.2). Mutations in the erg11 gene were analysed and isolates genotyped., Results: Ibrexafungerp showed high activity (MICs from 0.03 mg/L to 0.25 mg/L) against the isolates, including those with reduced azole susceptibility, and regardless of their clinical source. Fluconazole resistance rate was 7% (n = 5/72) and 1.4% (n = 1/72) in vaginal and blood isolates, respectively. Some amino acid substitutions in the Erg11 protein were observed exclusively in phenotypically fluconazole non-wild type. Population structure analysis suggested two genotype populations, one mostly involving isolates from blood samples (66.3%) and the mostly from vaginal samples (69.8%). The latter group hosted all fluconazole non-wild-type isolates., Discussion: Ibrexafungerp shows good in vitro activity against Candida albicans from vaginal samples including phenotypically fluconazole non-wild-type isolates. Furthermore, we found a certain population structure where some genotypes show reduced susceptibility to fluconazole., (Copyright © 2021 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

The objectives of this study were to gain further insight on Candida genotype distribution and percentage of clustered isolates between hospitals and to identify potential clusters involving different hospitals and cities. We aim to genotype Candida spp. isolates causing candidemia in patients admitted to 16 hospitals in Spain, Italy, Denmark, and Brazil. Eight hundred and eighty-four isolates ( Candida albicans, n = 534; C. parapsilosis, n = 282; and C. tropicalis, n = 68) were genotyped using species-specific microsatellite markers. CDC3, EF3, HIS3, CAI, CAIII, and CAVI were used for C. albicans , Ctrm1, Ctrm10, Ctrm12, Ctrm21, Ctrm24, and Ctrm28 for C. tropicalis , and CP1, CP4a, CP6, and B for C. parapsilosis . Genotypes were classified as singletons (genotype only found once) or clusters (same genotype infecting two or more patients). Clusters were defined as intra-hospital (involving patients admitted to a single hospital), intra-ward (involving patients admitted to the same hospital ward) or widespread (involving patients admitted to different hospitals). The percentage of clusters and the proportion of patients involved in clusters among species, genotypic diversity and distribution of genetic diversity were assessed. Seven hundred and twenty-three genotypes were detected, 78 (11%) being clusters, most of which (57.7%; n = 45/78) were intra-hospital clusters including intra-ward ones (42.2%; n = 19/45). The proportion of clusters was not statistically different between species, but the percentage of patients in clusters varied among hospitals. A number of genotypes (7.2%; 52/723) were widespread (found at different hospitals), comprising 66.7% (52/78) of clusters, and involved patients at hospitals in the same city ( n = 21) or in different cities ( n = 31). Only one C. parapsilosis cluster was a widespread genotype found in all four countries. Around 11% of C. albicans and C. parapsilosis isolates causing candidemia are clusters that may result from patient-to-patient transmission, widespread genotypes commonly found in unrelated patients, or insufficient microsatellite typing genetic discrimination., (Copyright © 2020 Guinea, Arendrup, Cantón, Cantón, García-Rodríguez, Gómez, de la Pedrosa, Hare, Orden, Sanguinetti, Pemán, Posteraro, Ruiz-Gaitán, Parisi, Da Matta, Colombo, Sánchez-Carrillo, Reigadas, Muñoz and Escribano.)

Background: The clinical relevance and the potential prognostic role of persistently negative (1,3)-β-D-glucan (BDG) in adults with proven candidemia is unknown., Methods: This retrospective study included all adults diagnosed with candidemia our tertiary university hospital from 2012-2017 who had at least 2 serum BDG determinations throughout the episode of fungemia (Fungitell Assay; positive cut-off ≥80pg/mL). Epidemiology and clinical outcomes were compared between patients with all negative versus any positive BDG tests. Poor clinical outcomes included complications due to candidemia or 30-day all-cause mortality., Results: Overall, 26/148 (17.6%) candidemic adults had persistently negative BDG tests. These patients were less likely to present Candida growth in all 3 sets of blood cultures (15.4% vs 45.1%; P = .005) and had less severe clinical presentations (median Pitt score, 0 [interquartile range {IQR} 0-1] vs 1 [IQR 0-2] in patients with any positive BDG test; P = .039). Although adequate treatment was equally provided to both groups (96.2% in persistently negative group vs 93.4 in positive group; P = .599), the persistently negative group had a higher rate of microbiological clearance in the first follow-up blood cultures (92.3% vs 69.7% in positive group; P = .005), fewer complications due to candidemia (7.7% vs 33.6% in positive group; P = .008), a lower 30-day mortality rate (3.8% vs 23.8% in positive group; P = .004), and a shorter in-hospital stay (34 days [IQR 18-55] vs 51 days [IQR 35-91] in positive group; P = .003). In the multivariate analysis, persistently negative BDG tests were independently associated with better prognoses (odds ratio 0.12, 95% confidence interval 0.03-0.49; P = .003)., Conclusions: Candidemic patients with persistently negative BDG tests present a better prognosis than the comparative group, probably due to a lower systemic fungal burden. In this context, the appropriate use of persistently negative BDG results could be an aid to individualize therapeutic management in the near future., (© The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

The high rates of antifungal resistance in Candida glabrata may be facilitated by the presence of alterations in the MSH2 gene. We aimed to study the sequence of the MSH2 gene in 124 invasive C. glabrata isolates causing incident episodes of candidemia ( n = 81), subsequent candidemia episodes ( n = 9), endocarditis ( n = 2), and in vitro -generated echinocandin-resistant isolates ( n = 32) and assessed its relationship with genotypes, acquisition of antifungal resistance in vivo and in vitro , and patient prognosis. The MSH2 gene was sequenced, and isolates were genotyped using six microsatellite markers and multilocus sequence typing (MLST) based on six housekeeping genes. According to EUCAST, isolates causing candidemia ( n = 90) were echinocandin susceptible, and four of them were fluconazole resistant (MIC ≥64 mg/liter). One isolate obtained from a heart valve was resistant to micafungin and anidulafungin (MICs, 2 mg/liter and 1 mg/liter, respectively). MSH2 gene mutations were present in 44.4% of the incident isolates, the most common being V239L. The presence of MSH2 mutations was not correlated with in vitro or in vivo antifungal resistance. Microsatellite and MLST revealed 27 genotypes and 17 sequence types, respectively. Fluconazole-resistant isolates were unrelated. Most MSH2 mutations were found in cluster isolates; conversely, some mutations were found in more than one genotype. No clinical differences, including previous antifungal use, were found between patients infected by wild-type MSH2 gene isolates and isolates with any point mutation. The presence of MSH2 gene mutations in C. glabrata isolates causing candidemia is not correlated with specific genotypes, the promotion of antifungal resistance, or the clinical outcome., (Copyright © 2018 American Society for Microbiology.)

The presence of clusters in units with a high incidence of candidemia suggests the need for the prevention of candidemia. We analyzed the percentage of patients involved in clusters and its evolution over a large period of time in a tertiary hospital. We studied 432 patients admitted to Gregorio Marañón Hospital with candidemia caused by Candida albicans ( n = 276) or Candida parapsilosis ( n = 156) between January 2007 and December 2014. Incident isolates were genotyped. A cluster was defined as a group of ≥2 patients infected by an identical genotype; we considered clusters to be "tracking clusters" when the patients involved in the cluster were admitted to the same ward within a period of 24 months. The study period was split into two periods, 2007 to 2010 (period 1) and 2011 to 2014 (period 2). The number of episodes of C. albicans and C. parapsilosis candidemia ( n = 262 versus n = 170, respectively), the mean incidence (1.62 versus 1.36 episodes per 1,000 admissions, respectively), and the percentage of episodes caused by clusters (overall clusters [40% versus 12%] and tracking clusters [18% versus 3%], respectively) were significantly lower in period 2 than in period 1. Linear regression analysis showed a positive correlation between the overall number of episodes of candidemia and episodes caused by clusters ( r = 0.89). We found a reduction in the number of episodes of candidemia caused by 2 = 0.89). We found a reduction in the number of episodes of candidemia caused by C. albicans and C. parapsilosis and a decrease in the percentage of episodes caused by clusters over time. Interestingly, the reduction was accompanied by the implementation of a campaign to reduce the number of catheter-related infections., (Copyright © 2018 American Society for Microbiology.)

The objectives of our study were to describe the characteristics of patients with Candida guilliermondii candidemia and to perform an in-depth microbiological characterization of isolates and compare them with those of patients with C. albicans candidemia. We described the risk factors and outcomes of 22 patients with candidemia caused by the C. guilliermondii complex. Incident isolates were identified using molecular techniques, and susceptibility to fluconazole, anidulafungin, and micafungin was studied. Biofilm formation was measured using the crystal violet assay (biomass production) and the XTT reduction assay (metabolic activity), and virulence was studied using the Galleria mellonella model. Biofilm formation was compared with that observed for C. albicans The main conditions predisposing to infection were malignancy (68%), immunosuppressive therapy (59%), and neutropenia (18%). Clinical presentation of candidemia was less severe in patients infected by the C. guilliermondii complex than in patients infected by C. albicans , and 30-day mortality was lower in C. guilliermondii patients (13.6% versus 33.9%, respectively; P = 0.049). Isolates were identified as C. guilliermondii sensu stricto ( n = 17) and Candida fermentati ( n = 5). The isolates produced biofilms with low metabolic activity and moderate biomass. The G. mellonella model showed that C. guilliermondii was less virulent than C. albicans < 0.001). Patients with candidemia caused by the P < 0.001). Patients with candidemia caused by the C. guilliermondii complex had severe and debilitating underlying conditions. Overall, the isolates showed diminished susceptibility to fluconazole and echinocandins, although poor biofilm formation and the low virulence were associated with a favorable outcome., (Copyright © 2017 American Society for Microbiology.)

Trailing is a well-known phenomenon that is defined as reduced but persistent visible growth of Candida spp. at fluconazole concentrations above the MIC. Trailing is commonly detected using the CLSI M27-A3 method, although little is known about its frequency when investigated with EUCAST. We assessed the frequency and scope of fluconazole trailing after using EUCAST EDef 7.2. against a large number of Candida spp. isolates from patients with candidemia. We studied 639 fluconazole-susceptible non-krusei Candida spp. isolates from 570 patients admitted to Gregorio Marañón Hospital. Isolates were tested in vitro for fluconazole susceptibility according to the EUCAST EDef 7.2 procedure; trailing was defined as the presence of any residual growth in wells containing fluconazole concentrations above the MIC. According to the mean percentage of trailing observed, isolates were classified as residual trailers (0.1-5%), slight trailers (6%-10%), moderate trailers (11%-15%), and heavy trailers (>15%). The relationship between trailing and genotyping was assessed. The mean overall percentage of trailing was 6.8%, with C. albicans and C. tropicalis showing the highest percentages (9.75% and 9.29%, respectively; P < .001). C. albicans and C. tropicalis had the highest percentage of heavy trailers (>15%). Trailing was not genotype-specific. Fluconazole trailing was observed frequently when EUCAST was used for antifungal susceptibility testing, particularly in isolates of C. albicans and C. tropicalis The cut-off proposed enabled us to classify the isolates according to the degree of trailing and can be used as the basis for future studies to evaluate the clinical impact of this phenomenon., (© The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Many bloodstream infections (BSI) in patients with central venous catheters (CVC) are not catheter-related (CR). Assessment of catheter involvement without catheter withdrawal has not been studied in candidemia. We assessed the value of conservative techniques to evaluate catheters as the origin of candidemia in patients with CVC in a prospective cohort study (superficial Gram stain and culture, Kite technique (Gram stain and culture of the first 1 cm blood drawn from the CVC), proportion of positive blood cultures (PPBCs), differential time to positivity (DTP), and minimal time to positivity (MTP)). All catheters were cultured at withdrawal. From June 2008 to January 2012, 22 cases fulfilled the inclusion criteria. CR-candidemia (CRC) was confirmed in 10. Validity values for predicting CRC were: superficial Gram stain (S, 30%; Sp, 81.83%; PPV, 60%; NPV, 56.3%; Ac, 57.1%), superficial cultures (S, 40%; Sp, 75%; PPV, 57.1%; NPV, 60%; Ac, 59.1%), Kite Gram stain (S, 33.3%; Sp, 66.7%; PPV, 50%; NPV, 50%; Ac, 50%), Kite culture (S, 80%; Sp, 66.7%; PPV, 66.7%; NPV, 80%; Ac, 72.7%), PPBC (S, 50%; Sp, 41.7%; PPV, 41.7%; NPV, 50.0%; Ac, 45.5%), DTP (S, 100%; Sp, 33.3%; PPV, 55.6%; NPV, 100%; Ac, 63.6%), and MTTP (S, 70%; Sp, 58.3%; PPV, 58.3%; NPV, 70%; Ac, 63.6%). While combinations of two tests improved sensitivity and NPV, more than two tests did not improve validity values. Classic tests to assess CR-BSI caused by bacteria cannot be reliably used to diagnose CRC. Combinations of tests could be useful, but more and larger studies are required., (© The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Genotyping of Candida albicans strains causing candidemia can uncover the presence of endemic genotypes in the hospital. Using a highly reproducible and discriminatory microsatellite marker panel, we studied the genetic diversity of 217 C. albicans isolates from the blood cultures of 202 patients with candidemia (from January 2007 to December 2011). Each isolate represented 1 candidemia episode. Multiple episodes were defined as the isolation of C. albicans in further blood cultures taken ≥7 days after the last isolation in blood culture. Of the 202 patients, 188 had 1 episode, 13 had 2 episodes, and 1 had 3 episodes. Identical genotypes showed the same alleles for all 6 markers. The genotypes causing both episodes were identical in most patients with 2 episodes (11/13; 84.6%). In contrast, 2 different genotypes were found in the patient with 3 episodes, one causing the first and second episodes and the other causing the third episode (isolated 6 months later). We found marked genetic diversity in 174 different genotypes: 155 were unique, and 19 were endemic and formed 19 clusters (2 to 6 patients per cluster). Up to 25% of the patients were infected by endemic genotypes that infected 2 or more different patients. Some of these endemic genotypes were found in the same unit of the hospital, mainly neonatology, whereas others infected patients in different wards.

There is scarce information on the actual incidence of candidemia in COVID-19 patients. In addition, comparative studies of candidemia episodes in COVID-19 and non-COVID-19 patients are heterogeneous. Here, we assessed the real incidence, epidemiology, and etiology of candidemia in COVID-19 patients, and compared them with those without COVID-19 (2020 vs. 2019 and 2020, respectively). We also genotyped all C. albicans, C. parapsilosis, and C. tropicalis isolates (n = 88), causing candidemia in both groups, providing for the first time a genotypic characterization of isolates gathered in patients with either COVID-19 or non-COVID-19. Incidence of candidemia was higher in patients with COVID-19 than non-COVID-19 (4.73 vs. 0.85 per 1000 admissions; 3.22 vs. 1.14 per 10,000 days of stay). No substantial intergroup differences were found, including mortality. Genotyping proved the presence of a low number of patients involved in clusters, allowing us to rule out rampant patient-to-patient Candida transmission. The four patients, involved in two clusters, had catheter-related candidemia diagnosed in the first COVID-19 wave, which demonstrates breaches in catheter management policies occurring in such an overwhelming situation. In conclusion, the incidence of candidemia in patients with COVID-19 is significantly higher than in those without COVID-19. However, genotyping shows that this increase is not due to uncontrolled intrahospital transmission. [ABSTRACT FROM AUTHOR]

Whole genome sequencing has been extensively used to describe infection outbreaks, although with limited application on Candida albicans and Candida parapsilosis. We retrospectively studied all patients admitted to the neonatal care unit diagnosed with candidemia caused by C. albicans (n = 46) or C. parapsilosis (n = 31) between 2007 and 2010 (Period 1) and 2011 and 2014 (Period 2). All isolates were genotyped by microsatellite markers. A cluster was defined as a group of ≥ 2 patients infected by strains with identical genotypes. For the validation of microsatellite markers and outbreak investigation, phylogenetic analyses and whole genome pairwise strain comparisons were performed. The number of episodes was significantly higher in Period 1 than in Period 2 (51 vs 32; P  = 0.003); the reduction in the number of cases coincided with the educational campaign for catheter care implementation in 2011. Overall, eight genotypes were clusters involving 29 patients. All C. albicans (n = 5) and C. parapsilosis (n = 3) clusters were found during Period 1 before the educational campaign. No statistically significant differences were found between the percentage of C. albicans and C. parapsilosis clusters, but the percentage of patients associated to the clusters was significantly higher for C. parapsilosis clusters in comparison to C. albicans clusters (52 vs 28.2%; P  = 0.03). Whole genome sequencing confirmed microsatellite-defined clusters with high bootstrap values. Whole genome sequences confirmed microsatellite-defined clusters, corroborating the presence of outbreaks. Persistent or sporadic Candida clusters causing candidemia in neonates disappeared after the implementation of catheter care educational campaigns. Lay summary We retrospectively studied all patients admitted to the neonatal care unit diagnosed with candidemia caused by C. albicans or C. parapsilosis. Reliable whole genome sequences confirmed microsatellite-defined clusters, corroborating the presence of outbreaks before educational campaigns for catheter care. [ABSTRACT FROM AUTHOR]

The capacity of Candida spp. to form biofilms allows them to attach either to living or inert surfaces, promoting their persistence in hospital environments. In a previous study, we reported strain-to-strain variations in Candida spp. biofilm development, suggesting that some genotypes may be greater biofilm formers than others. In this study, we hypothesize that isolates pertaining to clusters may be found more frequently in the environment due to their ability to form biofilms compared to singleton genotypes. Two hundred and thirty-nine Candida spp. isolates (78 clusters) from candidemia patients admitted to 16 hospitals located in different cities and countries—and the same number of singleton genotypes used as controls—were tested in terms of biofilm formation using the crystal violet and the XTT reduction assays. Candida albicans clusters showed higher biofilm formation in comparison to singleton genotypes (P  < .01). The biofilms formed by intra-hospital C. albicans clusters showed higher metabolic activity (P  < .05). Furthermore, marked variability was found among species and type of cluster. We observed that the higher the number of isolates, the higher the variability of biofilm production by isolates within the cluster, suggesting that the production of biofilm by isolates of the same genotype is quite diverse and does not depend on the type of cluster studied. In conclusion, candidemia Candida spp. clusters—particularly in the case of C. albicans —show significantly more biomass production and metabolic activity than singleton genotypes. [ABSTRACT FROM AUTHOR]

Candida Genotyping of Blood Culture Isolates from Patients Admitted to 16 Hospitals in Madrid: Genotype Spreading during the COVID-19 Pandemic Driven by Fluconazole-Resistant C. parapsilosis. Figure Graph: Figure 2 Numbers (and percentage) of patients involved in singleton and intra-hospital clusters per species over the study period. Reference 1 Díaz-García J., Gómez A., Machado M., Alcalá L., Reigadas E., Sánchez-Carrillo C., Pérez-Ayala A., de la Pedrosa E.G.-G., González-Romo F., Cuétara M.S. Candida Genotyping of Blood Culture Isolates from Patients Admitted to 16 Hospitals in Madrid: Genotype Spreading during the COVID-19 Pandemic Driven by Fluconazole-Resistant C. parapsilosis. [Extracted from the article]

Isavuconazole is a triazole previously shown to have potent in vitro activity against Aspergillus spp., Mucorales, and Candida spp. Unlike for other azoles, it is unclear if isavuconazole may induce a trailing effect. We studied isavuconazole MICs for a large collection of Candida isolates from blood samples and determined the extent of the trailing effect when using the EUCAST Edef 7.3.1 method. 761 molecularly identified Candida isolates from blood samples of 742 patients admitted to the hospital (January 2007 to September 2017) were evaluated and further tested for in vitro susceptibility to isavuconazole following the EUCAST E.Def 7.3.1 test method. C. albicans showed the highest susceptibility, followed by C. parapsilosis and C. tropicalis (geometric mean MIC 0.003 vs 0.005/0.006, respectively; P < 0.001). In contrast, C. glabrata, and C. krusei had significantly higher MIC values (geometric mean MIC 0.094 vs 0.093, respectively). Isavuconazole MIC distributions were not truncated at the lowest concentration tested, except for C. albicans. Overall, the mean percentage of trailing was 12.9% but differences among species were observed: C. glabrata , C. albicans , and C. tropicalis exhibited higher trailing in comparison to C. parapsilosis and non- Candida yeasts (P < 0.001). The percentage of non-wild-type C. albicans (considering the heavy trailer isolates as wild-type), C. parapsilosis and C. glabrata isolates were 0.56% (2/355), 1.5% (3/200), and 4.65% (4/86), respectively. Isavuconazole showed high in vitro activity against Candida spp., particularly against C. albicans. Trailing effect is commonly observed with isavuconazole, particularly with C. glabrata. [ABSTRACT FROM AUTHOR]