Epidemiology and predictors of mortality in cases of Candida bloodstream infection: results from population-based surveillance, barcelona, Spain, from 2002 to 2003

A highly conserved tRNA modification contributes to C. albicans filamentation and virulence

tRNA modifications play important roles in maintaining translation accuracy in all domains of life. Disruptions in the tRNA modification machinery, especially of the anticodon stem loop, can be lethal for many bacteria and lead to a broad range of phenotypes in baker's yeast. Very little is known about the function of tRNA modifications in host-pathogen interactions, where rapidly changing environments and stresses require fast adaptations. We found that two closely related fungal pathogens of humans, the highly pathogenic Candida albicans and its much less pathogenic sister species, Candida dubliniensis, differ in the function of a tRNA-modifying enzyme. This enzyme, Hma1, exhibits species-specific effects on the ability of the two fungi to grow in the hypha morphology, which is central to their virulence potential. We show that Hma1 has tRNA-threonylcarbamoyladenosine dehydratase activity, and its deletion alters ribosome occupancy, especially at 37°C-the body temperature of the human host. A C. albicans HMA1 deletion mutant also shows defects in adhesion to and invasion into human epithelial cells and shows reduced virulence in a fungal infection model. This links tRNA modifications to host-induced filamentation and virulence of one of the most important fungal pathogens of humans.IMPORTANCEFungal infections are on the rise worldwide, and their global burden on human life and health is frequently underestimated. Among them, the human commensal and opportunistic pathogen, Candida albicans, is one of the major causative agents of severe infections. Its virulence is closely linked to its ability to change morphologies from yeasts to hyphae. Here, this ability is linked-to our knowledge for the first time-to modifications of tRNA and translational efficiency. One tRNA-modifying enzyme, Hma1, plays a specific role in C. albicans and its ability to invade the host. This adds a so-far unknown layer of regulation to the fungal virulence program and offers new potential therapeutic targets to fight fungal infections.

Association between selective digestive decontamination and decreased rate of acquired candidemia in mechanically ventilated ICU patients: a multicenter nationwide study

BACKGROUND

Candidemia is a high-risk complication among intensive care unit (ICU) patients. While selective digestive decontamination (SDD) has been shown to be effective in preventing ICU-acquired bacterial secondary infection, its effects on ICU-acquired candidemia (ICAC) remain poorly explored. Therefore, we sought to assess the effects of SDD on ICAC.

METHOD

Using the REA-REZO network, we included adult patients receiving mechanical ventilation for at least 48 h from January 2017 to January 2023. Non-parsimonious propensity score matching with a 1:1 ratio was performed to investigate the association between SDD and the rate of ICAC.

RESULTS

A total of 94 437 patients receiving at least 48 h of mechanical ventilation were included throughout the study period. Of those, 3 001 were treated with SDD and 651 patients developed ICAC. The propensity score matching included 2 931 patients in the SDD group and in the standard care group. In the matched cohort analysis as well as in the overall population, the rate of ICAC was lower in patients receiving SDD (0.8% versus 0.3%; p = 0.012 and 0.7% versus 0.3%; p = 0.006, respectively). Patients with ICAC had higher mortality rate (48.4% versus 29.8%; p < 0.001). Finally, mortality rates as well as ICU length of stay in the matched populations did not differ according to SDD (31.0% versus 31.1%; p = 0.910 and 9 days [5-18] versus 9 days [5-17]; p = 0.513, respectively).

CONCLUSION

In this study with a low prevalence of ICAC, SDD was associated with a lower rate of ICAC that did not translate to higher survival.

Analysis of 15 cases from a monocentric cohort of 307 liver abscesses

BACKGROUND

Out of the context of haematological patients, Candida sp. is rarely retrieved from pyogenic liver abscesses (PLA).

OBJECTIVES

Our objective was to assess the risk factors for occurrence, and clinical, microbiological characteristics, management and outcome of Candida pyogenic liver abscesses (C-PLA).

PATIENTS/METHODS

We retrospectively analysed C-PLA cases and compared them to pyogenic liver abscesses exclusively due to bacteria (B-PLA) included in our monocentric database on liver abscesses. Unfavourable course was defined as the occurrence of a primary treatment failure (PTF), recurrence after an initial cure, or death within 3 months after diagnosis.

RESULTS

Between 2010 and 2018, 15 C-PLA and 292 B-PLA were included. All C-PLA had a biliary origin and were polymicrobial. All patients with C-PLA had at least one comorbidity at risk for Candida infection and 7 (53.3%) presented with sepsis requiring an admission in intensive care unit. Median duration of antifungal treatment was 42 days [24-55]. In multivariate analysis, compared with B-PLA, a medical history of malignancy (OR 4.16; 95%CI 1.15-18.72) or liver abscess (OR 7.39; 95%CI 2.10-26.62), and sepsis with severity criteria (OR 3.52; 95%CI 1.07-11.90) were independently associated with the occurrence of C-PLA. In multivariate analysis, C-PLA was associated with a higher risk of recurrence (HR 3.08; 95%CI 1.38-11.22).

CONCLUSION

Candida liver abscesses in non-neutropenic is a rare and severe disease. The high rate of recurrence should lead to discuss a more intensive treatment.

Thymoquinone Antifungal Activity against Candida glabrata Oral Isolates from Patients in Intensive Care Units-An In Vitro Study

The number of Candida spp. infections and drug resistance are dramatically increasing worldwide, particularly among immunosuppressed patients, and it is urgent to find novel compounds with antifungal activity. In this work, the antifungal and antibiofilm activity of thymoquinone (TQ), a key bioactive constituent of black cumin seed Nigella sativa L., was evaluated against Candida glabrata, a WHO 'high-priority' pathogen. Then, its effect on the expression of C. glabrata EPA6 and EPA7 genes (related to biofilm adhesion and development, respectively) were analyzed. Swab samples were taken from the oral cavity of 90 hospitalized patients in ICU wards, transferred to sterile falcon tubes, and cultured on Sabouraud Dextrose Agar (SDA) and Chromagar Candida for presumptive identification. Next, a 21-plex PCR was carried out for the confirmation of species level. C. glabrata isolates underwent antifungal drug susceptibility testing against fluconazole (FLZ), itraconazole (ITZ), amphotericin B (AMB), and TQ according to the CLSI microdilution method (M27, A3/S4). Biofilm formation was measured by an MTT assay. EPA6 and EPA7 gene expression was assessed by real-time PCR. From the 90 swab samples, 40 isolates were identified as C. glabrata with the 21-plex PCR. Most isolates were resistant to FLZ (n = 29, 72.5%), whereas 12.5% and 5% were ITZ and AMB resistant, respectively. The minimum inhibitory concentration (MIC₅₀) of TQ against C. glabrata was 50 µg/mL. Importantly, TQ significantly inhibited the biofilm formation of C. glabrata isolates, and EPA6 gene expression was reduced significantly at MIC₅₀ concentration of TQ. TQ seems to have some antifungal, antibiofilm (adhesion) effect on C. glabrata isolates, showing that this plant secondary metabolite is a promising agent to overcome Candida infections, especially oral candidiasis.

Candida Bezoar of the Bladder Resulting in Obstructive Uropathy: A Case Report

Candida bezoar is a rare pathologic entity characterized by the colonization of a cavity by an aggregate or mass of mycelia due to local or systemic infections with Candida spp. Candida bezoar is commonly seen in immunocompromised individuals and can often present in the context of symptomatic urinary tract infection or urosepsis. The implicated risk factors for the development of Candida bezoars are anatomical urinary tract abnormalities, diabetes mellitus, indwelling urinary catheters, increased use of broad-spectrum antibiotics, and corticosteroids. Early clinical suspicion is essential for diagnosis to prevent the dissemination of disease and for a favorable prognosis. We report a case of a 49-year-old diabetic male who presents with hematuria, abnormal urinary flow, and left-sided flank pain for four days caused by a Candida bezoar of the urinary bladder resulting in unilateral obstructive uropathy despite the appropriate placement of a ureteral stent. Treatment with left nephrostomy tube, oral fluconazole, and amphotericin bladder irrigation for three days was successful. The patient's condition improved, and he was discharged on fluconazole and was recommended to follow up with urology as an outpatient.

Evolution of Fluconazole Resistance Mechanisms and Clonal Types of Candida parapsilosis Isolates from a Tertiary Care Hospital in South Korea

We investigated the evolution of fluconazole resistance mechanisms and clonal types of Candida parapsilosis isolates from a tertiary care hospital in South Korea. A total of 45 clinical isolates, including 42 collected between 2017 and 2021 and 3 collected between 2012 and 2013, were subjected to antifungal susceptibility testing, sequencing of fluconazole resistance genes (ERG11, CDR1, TAC1, and MRR1), and microsatellite typing. Twenty-two isolates carried Y132F (n = 21; fluconazole MIC = 2 to >256 mg/L) or Y132F+R398I (n = 1; fluconazole MIC = 64 mg/L) in ERG11 and four isolates harbored N1132D in CDR1 (fluconazole MIC = 16 to 64 mg/L). All 21 Y132F isolates exhibited similar microsatellite profiles and formed a distinct group in the dendrogram. All four N1132D isolates displayed identical microsatellite profiles. Fluconazole MIC values of the Y132F isolates varied depending on their MRR1 mutation status (number of isolates, year of isolation, and MIC): K177N (n = 8, 2012 to 2020, 2 to 8 mg/L); K177N + heterozygous G982R (n = 1, 2017, 64 mg/L); K177N + heterozygous S614P (n = 2, 2019 to 2020, 16 mg/L); and K177N + homozygous S614P (n = 10, 2020 to 2021, 64 to > 256 mg/L). Our study revealed that Y132F in ERG11 and N1132D in CDR1 were the major mechanisms of fluconazole resistance in C. parapsilosis isolates. Furthermore, our results suggested that the clonal evolution of Y132F isolates persisting and spreading in hospital settings for several years occurred with the acquisition of heterozygous or homozygous MRR1 mutations associated with a gradual increase in fluconazole resistance.

Curcumin affects function of Hsp90 and drug efflux pump of Candida albicans

Candida albicans is a pathogenic yeast that causes candidiasis in immunocompromised patients. The overuse of antifungal drugs has led to the development of resistance to such drugs by this fungus, which is a major challenge in antifungal chemotherapy. One approach to this problem involves the utilization of new natural products as an alternative source of antifungals. Curcumin, one such natural product, has been widely studied as a drug candidate and is reported to exhibit antifungal activity against C. albicans. Although studies of the mechanism of curcumin against human cancer cells have shown that it inhibits heat shock protein 90 (Hsp90), little is known about its function against C. albicans. In this paper, using a doxycycline-mediated HSP90 strain and an HSP90-overexpressing strain of C. albicans, we demonstrated that the curcumin triggered a decrease in Hsp90 by affecting it at the post-transcriptional level. This also led to the downregulation of HOG1 and CDR1, resulting in a reduction of the stress response and efflux pump activity of C. albicans. However, the inhibition of HSP90 by curcumin was not due to the inhibition of transcription factors HSF1 or AHR1. We also found that curcumin can not only decrease the transcriptional expression of CDR1, but also inhibit the efflux pump activity of Cdr1. Hence, we conclude that disruption of HSP90 by curcumin could impair cell growth, stress responses and efflux pump activity of C. albicans.

Assessment of Biofilm Formation by Candida albicans Strains Isolated from Hemocultures and Their Role in Pathogenesis in the Zebrafish Model

Candida albicans, an opportunistic pathogen, has the ability to form biofilms in the host or within medical devices in the body. Biofilms have been associated with disseminated/invasive disease with increased severity of infection by disrupting the host immune response and prolonging antifungal treatment. In this study, the in vivo virulence of three strains with different biofilm formation strengths, that is, non-, weak-, and strong biofilm formers, was evaluated using the zebrafish model. The survival assay and fungal tissue burden were measured. Biofilm-related gene expressions were also investigated. The survival of zebrafish, inoculated with strong biofilms forming C. albicans,, was significantly shorter than strains without biofilms forming C. albicans. However, there were no statistical differences in the burden of viable colonogenic cell number between the groups of the three strains tested. We observed that the stronger the biofilm formation, the higher up-regulation of biofilm-associated genes. The biofilm-forming strain (140 and 57), injected into zebrafish larvae, possessed a higher level of expression of genes associated with adhesion, attachment, filamentation, and cell proliferation, including eap1, als3, hwp1, bcr1, and mkc1 at 8 h. The results suggested that, despite the difference in genetic background, biofilm formation is an important virulence factor for the pathogenesis of C. albicans. However, the association between biofilm formation strength and in vivo virulence is controversial and needs to be further studied.

Continuing Shifts in Epidemiology and Antifungal Susceptibility Highlight the Need for Improved Disease Management of Invasive Candidiasis

Invasive candidiasis (IC) is a systemic life-threatening infection of immunocompromised humans, but remains a relatively neglected disease among public health authorities. Ongoing assessments of disease epidemiology are needed to identify and map trends of importance that may necessitate improvements in disease management and patient care. Well-established incidence increases, largely due to expanding populations of patients with pre-disposing risk factors, has led to increased clinical use and pressures on antifungal drugs. This has been exacerbated by a lack of fast, accurate diagnostics that have led treatment guidelines to often recommend preventative strategies in the absence of proven infection, resulting in unnecessary antifungal use in many instances. The consequences of this are multifactorial, but a contribution to emerging drug resistance is of primary concern, with high levels of antifungal use heavily implicated in global shifts to more resistant Candida strains. Preserving and expanding the utility and number of antifungals should therefore be of the highest priority. This may be achievable through the development and use of biomarker tests, bringing about a new era in improved antifungal stewardship, as well as novel antifungals that offer favorable profiles by targeting Candida pathogenesis mechanisms over cell viability.

Microbiological quality analysis of inoculants based on Bradyrhizobium spp. and Azospirillum brasilense produced "on farm" reveals high contamination with non-target microorganisms

The use of inoculants carrying diazotrophic and other plant growth-promoting bacteria plays an essential role in the Brazilian agriculture, with a growing use of microorganism-based bioproducts. However, in the last few years, some farmers have multiplied microorganisms in the farm, known as "on farm" production, including inoculants of Bradyrhizobium spp. for soybean (Glycine max L. Merrill.) and Azospirillum brasilense for corn (Zea mays L.) or co-inoculation in soybean. The objective was to assess the microbiological quality of such inoculants concerning the target microorganisms and contaminants. In the laboratory, 18 samples taken in five states were serial diluted and spread on culture media for obtaining pure and morphologically distinct colonies of bacteria, totaling 85 isolates. Molecular analysis based on partial sequencing of the 16S rRNA gene revealed 25 genera of which 44% harbor species potentially pathogenic to humans; only one of the isolates was identified as Azospirillum brasilense, whereas no isolate was identified as Bradyrhizobium. Among 34 isolates belonging to genera harboring species potentially pathogenic to humans, 12 had no resistance to antibiotics, six presented intrinsic resistance, and 18 presented non-intrinsic resistance to at least one antibiotic. One of the samples analyzed with a shotgun-based metagenomics approach to check for the microbial diversity showed several genera of microorganisms, mainly Acetobacter (~ 32% of sequences) but not the target microorganism. The samples of inoculants produced on farm were highly contaminated with non-target microorganisms, some of them carrying multiple resistances to antibiotics.

Surveillance of Antifungal Resistance in Candidemia Fails to Inform Antifungal Stewardship in European Countries

Background: The increasing burden of candidemia and the emergence of resistance, especially among non-Candida albicans strains, represent a new threat for public health. We aimed to assess the status of surveillance and to identify publicly accessible resistance data in Candida spp blood isolates from surveillance systems and epidemiological studies in 28 European and 4 European Free Trade Association member states. Methods: A systematic review of national and international surveillance networks, from 2015 to 2020, and peer-reviewed epidemiological surveillance studies, from 2005 to 2020, lasting for at least 12 consecutive months and with at least two centers involved, was completed to assess reporting of resistance to amphotericin B, azoles, and echinocandins in C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, and C. auris. Results: Only 5 (Austria, Italy, Norway, Spain, and United Kingdom) of 32 countries provided resistance data for Candida spp blood isolates. Among 322 surveillance studies identified, 19 were included from Belgium, Denmark, Iceland, Italy, Portugal, Spain, Sweden, Switzerland, and United Kingdom. C. albicans and C. glabrata were the most monitored species, followed by C. parapsilosis and C. tropicalis. C. krusei was not included in any national surveillance system; 13 studies assessed resistance. No surveillance system or study reported resistance for C. auris. Fluconazole, voriconazole, caspofungin, and amphotericin B resistance in C. albicans, C. glabrata, and C. parapsilosis were the most common drug–species combination monitored. Quality of surveillance data was poor, with only two surveillance systems reporting microbiological methods and clinical data. High heterogeneity was observed in modalities of reporting, data collection, and definitions. Conclusion: Surveillance of antifungal resistance in Candida spp blood-isolates is fragmented and heterogeneous, delaying the application of a translational approach to the threat of antifungal resistance and the identification of proper targets for antifungal stewardship activities. International efforts are needed to implement antifungal resistance surveillance programs in order to adequately monitor antifungal resistance.

The Flo Adhesin Family

The first step in the infection of fungal pathogens in humans is the adhesion of the pathogen to host tissue cells or abiotic surfaces such as catheters and implants. One of the main players involved in this are the expressed cell wall adhesins. Here, we review the Flo adhesin family and their involvement in the adhesion of these yeasts during human infections. Firstly, we redefined the Flo adhesin family based on the domain architectures that are present in the Flo adhesins and their functions, and set up a new classification of Flo adhesins. Next, the structure, function, and adhesion mechanisms of the Flo adhesins whose structure has been solved are discussed in detail. Finally, we identified from Pfam database datamining yeasts that could express Flo adhesins and are encountered in human infections and their adhesin architectures. These yeasts are discussed in relation to their adhesion characteristics and involvement in infections.

Impact of Nutritional Assessment on the Clinical Outcomes of Patients with Non-albicans Candidemia: A Multicenter Study

Several studies have demonstrated that malnutrition is a negative prognostic factor for clinical outcomes. However, there is limited evidence for the effect of malnutrition on clinical outcomes in patients with candidemia. We investigated the relationship between malnutrition and all-cause 28-day mortality among patients with non-albicans candidemia. Between July 2011 and June 2014, all adult patients with non-albicans candidemia, including C. tropicalis, C. glabrata, C. parapsilosis and so on, were enrolled. The Malnutrition Universal Screening Tool (MUST) scores were used to determine the patients' nutritional status before the onset of candidemia. A total of 378 patients were enrolled; 43.4% developed septic shock and 57.1% had a high risk of malnutrition (MUST ≥ 2). The all-cause 28-day mortality rate was 40.7%. The Cox proportional hazards model revealed that C. tropicalis (HR, 2.01; 95% CI, 1.24-3.26; p = 0.005), Charlson comorbidity index (HR, 1.10; 95% CI, 1.03-1.18; p = 0.007), Foley catheter use (HR, 1.68; 95% CI, 1.21-1.35; p = 0.002), concomitant bacterial infections (HR, 1.55; 95% CI, 1.11-2.17; p = 0.010), low platelet count (HR, 3.81; 95% CI, 2.45-5.91; p < 0.001), not receiving antifungals initially (HR, 4.73; 95% CI, 3.07-7.29; p < 0.001), and MUST ≥ 2 (HR, 1.54; 95% CI, 1.09-2.17; p = 0.014) were independently associated with all-cause 28-day mortality. A simple screening tool for nutritional assessment should be used for patients with non-albicans candidemia to detect early clinical deterioration, and a tailored nutritional care plan should be established for malnourished individuals, to improve their clinical outcomes.

Risk Factors of Candida parapsilosis Catheter-Related Bloodstream Infection

Catheter-related bloodstream infection (CRBSI) is an important healthcare-associated infection caused by various nosocomial pathogens. Candida parapsilosis has emerged as a crucial causative agent for the CRBSI in the last two decades. Many factors have been associated with the development of CRBSI including, demography, pre-maturity, comorbidities (diabetes mellitus, hypertension, heart diseases, neuropathy, respiratory diseases, renal dysfunction, hematological and solid organ malignancies, and intestinal dysfunction), intensive care unit (ICU) admission, mechanical ventilation (MV), total parenteral nutrition (TPN), prior antibiotic and/or antifungal therapy, neutropenia, prior surgery, immunosuppressant, and type, site, number, and duration of catheters. This study aims to determine C. parapsilosis CRBSI risk factors. A retrospective study has been performed in an 853-bedded tertiary-care hospital in north-eastern Malaysia. All inpatients with C. parapsilosis positive blood cultures from January 2006 to December 2018 were included, and their medical records were reviewed using a standardized checklist. Out of 208 candidemia episodes, 177 had at least one catheter during admission, and 31 cases had not been catheterized and were excluded. Among the 177 cases, 30 CRBSI cases were compared to 147 non-CRBSI cases [81 bloodstream infections (BSIs), 66 catheter colonizers]. The significance of different risk factors was calculated using multivariate analysis. Multivariate analysis of potential risk factors shows that ICU admission was significantly associated with non-CRBSI as compared to CRBSI [OR, 0.242; 95% CI (0.080-0.734); p = 0.012], and TPN was significantly positively associated with CRBSI than non-CRBSI [OR, 3.079; 95%CI (1.125-8.429); p = 0.029], while other risk factors were not associated significantly. Patients admitted in ICU were less likely to develop C. parapsilosis CRBSI while patients receiving TPN were more likely to have C. parapsilosis CRBSI when compared to the non-CRBSI group.

Dynamics and Predictors of Mortality Due to Candidemia Caused by Different Candida Species: Comparison of Intensive Care Unit-Associated Candidemia (ICUAC) and Non-ICUAC

We investigated mortality and predictors of mortality due to intensive care unit-associated candidemia (ICUAC) versus non-ICUAC by Candida species. This study included all candidemia cases in 11 hospitals from 2017 to 2018 in South Korea. The all-cause mortality rates in all 370 patients with ICUAC were approximately twofold higher than those in all 437 patients with non-ICUAC at 7 days (2.3-fold, 31.1%/13.3%), 30 days (1.9-fold, 49.5%/25.4%), and 90 days (1.9-fold, 57.8%/30.9%). Significant species-specific associations with 7- and 30-day ICUAC-associated mortality were not observed. Multivariate analysis revealed that ICU admission was an independent predictor of Candida glabrata (OR, 2.07–2.48) and Candida parapsilosis-associated mortality (OR, 6.06–11.54). Fluconazole resistance was a predictor of C. glabrata-associated mortality (OR, 2.80–5.14). Lack (less than 3 days) of antifungal therapy was the strongest predictor of 7-day mortality due to ICUAC caused by Candida albicans (OR, 18.33), Candida tropicalis (OR, 10.52), and C. glabrata (OR, 21.30) compared with 30- and 90-day mortality (OR, 2.72–6.90). C. glabrata ICUAC had a stronger association with lack of antifungal therapy (55.2%) than ICUAC caused by other species (30.6–36.7%, all p < 0.05). Most predictors of mortality associated with ICUAC were distinct from those associated with non-ICUAC and were mediated by Candida species.

Antimycotic Drugs and their Mechanisms of Resistance to Candida Species

Fungal infections have shown an upsurge in recent decades, which is mainly because of the increasing number of immunocompromised patients and the occurrence of invasive candidiasis has been found to be 7-15 fold greater than that of invasive aspergillosis. The genus Candida comprises more than 150 distinct species, however, only a few of them are found to be pathogenic to humans. Mortality rates of Candida species are found to be around 45% and the reasons for this intensified mortality are inefficient diagnostic techniques and unfitting initial treatment strategies. There are only a few antifungal drug classes that are employed for the remedy of invasive fungal infections. which include azoles, polyenes, echinocandins, and pyrimidine analogs. During the last 2-3 decades, the usage of antifungal drugs has increased several folds due to which the reports of escalating antifungal drug resistance have also been recorded. The resistance is mostly to the triazole- based compounds. Due to the occurrence of antifungal drug resistance, the success rates of treatment have been reduced as well as major changes have been observed in the frequency of fungal infections. In this review, we have summarized the major molecular mechanisms for the development of antifungal drug resistance.

Sphingolipid Inhibitors as an Alternative to Treat Candidiasis Caused by Fluconazole-Resistant Strains

Candida species are fungal pathogens known to cause a wide spectrum of diseases, and Candida albicans and Candida glabrata are the most common associated with invasive infections. A concerning aspect of invasive candidiasis is the emergence of resistant isolates, especially those highly resistant to fluconazole, the first choice of treatment for these infections. Fungal sphingolipids have been considered a potential target for new therapeutic approaches and some inhibitors have already been tested against pathogenic fungi. The present study therefore aimed to evaluate the action of two sphingolipid synthesis inhibitors, aureobasidin A and myriocin, against different C. albicans and C. glabrata strains, including clinical isolates resistant to fluconazole. Susceptibility tests of aureobasidin A and myriocin were performed using CLSI protocols, and their interaction with fluconazole was evaluated by a checkerboard protocol. All Candida strains tested were sensitive to both inhibitors. Regarding the evaluation of drug interaction, both aureobasidin A and myriocin were synergic with fluconazole, demonstrating that sphingolipid synthesis inhibition could enhance the effect of fluconazole. Thus, these results suggest that sphingolipid inhibitors in conjunction with fluconazole could be useful for treating candidiasis cases, especially those caused by fluconazole resistant isolates.

Deciphering the epidemiology of invasive candidiasis in the intensive care unit: is it possible?

Invasive candidiasis (IC) has emerged in the last decades as an important cause of morbidity, mortality, and economic load in the intensive care unit (ICU). The epidemiology of IC is still a difficult and unsolved enigma for the literature. Accurate estimation of the true burden of IC is difficult due to variation in definitions and limitations inherent to available case-finding methodologies. Candidemia and intra-abdominal candidiasis (IAC) are the two predominant types of IC in ICU. During the last two decades, an increase in the incidence of candidemia has been constantly reported particularly in the expanding populations of elderly or immunosuppressed patents, with a parallel change in Candida species (spp.) distribution worldwide. Epidemiological shift in non-albicans spp. has reached worrisome trends. Recently, a novel, multidrug-resistant Candida spp., Candida auris, has globally emerged as a nosocomial pathogen causing a broad range of healthcare-associated invasive infections. Epidemiological profile of IAC remains imprecise. Though antifungal drugs are available for Candida infections, mortality rates continue to be high, estimated to be up to 50%. Increased use of fluconazole and echinocandins has been associated with the emergence of resistance to these drugs, which affects particularly C. albicans and C. glabrata. Crucial priorities for clinicians are to recognize the epidemiological trends of IC as well as the emergence of resistance to antifungal agents to improve diagnostic techniques and strategies, develop international surveillance networks and antifungal stewardship programmes for a better epidemiological control of IC.

Mixed biofilms of pathogenic Candida-bacteria: regulation mechanisms and treatment strategies

Mixed-species biofilm is one of the most frequently recorded clinical problems. Mixed biofilms develop as a result of interactions between microorganisms of a single or multiple species (e.g. bacteria and fungi). Candida spp., particularly Candida albicans, are known to associate with various bacterial species to form a multi-species biofilm. Mixed biofilms of Candida spp. have been previously detected in vivo and on the surfaces of many biomedical instruments. Treating infectious diseases caused by mixed biofilms of Candida and bacterial species has been challenging due to their increased resistance to antimicrobial drugs. Here, we review and discuss the clinical significance of mixed Candida-bacteria biofilms as well as the signalling mechanisms involved in Candida-bacteria interactions. We also describe possible approaches for combating infections associated with mixed biofilms, such as the use of natural or synthetic drugs and combination therapy. The review presented here is expected to contribute to the advances in the biomedical field on the understanding of underlying interaction mechanisms of pathogens in mixed biofilm, and alternative approaches to treating the related infections.

Candidaemia in Central Slovenia: A 12-year retrospective survey

BACKGROUND

Candida bloodstream infections (BSI) became an important invasive disease in the late 20th century, in particular among immunocompromised patients. Although considerable progress has been made in the management of patients with invasive mycoses, Candida BSI are still widespread among hospitalised patients and are associated with relatively high mortality.

OBJECTIVES

We conducted a retrospective study to evaluate patient characteristics, incidence, species distribution and antifungal susceptibility of BSI isolates of Candida spp. as well as outcomes of Candida BSI from 2001 to 2012, before the widespread use of echinocandins. This is the first epidemiological study of Candida BSI in Slovenia so far.

METHODS

All documented candidaemia cases from 2001 to 2012 in two major hospitals-University Medical Centre and Institute of Oncology in Ljubljana, Slovenia-were taken into consideration. Candida BSI were identified in 422 patients (250 male, 172 female). Laboratory and clinical data of these patients were retrospectively analysed. Mann-Whitney U test was used to compare continuous variables and Fisher's exact test or chi-squared test for categorical variables.

RESULTS AND CONCLUSIONS

The average incidence of Candida BSI was 0.524/10.000 patient-days (0,317/1000 admissions); 16/422 were younger than 1 year and 251/422 patients were over 60 years old. The most commonly isolated species were Candida albicans and Candida glabrata, followed by Candida parapsilosis. Majority of the patients had a single episode of Candida BSI, multiple episodes of Candida BSI occurred in 18/434 patients (4.1%); in 25/434 patients (5.8%) mixed Candida BSI were observed. Crude 30-day case-fatality rate was 55.4%.

Population genomics of the pathogenic yeast Candida tropicalis identifies hybrid isolates in environmental samples

Candida tropicalis is a human pathogen that primarily infects the immunocompromised. Whereas the genome of one isolate, C. tropicalis MYA-3404, was originally sequenced in 2009, there have been no large-scale, multi-isolate studies of the genetic and phenotypic diversity of this species. Here, we used whole genome sequencing and phenotyping to characterize 77 isolates of C. tropicalis from clinical and environmental sources from a variety of locations. We show that most C. tropicalis isolates are diploids with approximately 2-6 heterozygous variants per kilobase. The genomes are relatively stable, with few aneuploidies. However, we identified one highly homozygous isolate and six isolates of C. tropicalis with much higher heterozygosity levels ranging from 36-49 heterozygous variants per kilobase. Our analyses show that the heterozygous isolates represent two different hybrid lineages, where the hybrids share one parent (A) with most other C. tropicalis isolates, but the second parent (B or C) differs by at least 4% at the genome level. Four of the sequenced isolates descend from an AB hybridization, and two from an AC hybridization. The hybrids are MTLa/α heterozygotes. Hybridization, or mating, between different parents is therefore common in the evolutionary history of C. tropicalis. The new hybrids were predominantly found in environmental niches, including from soil. Hybridization is therefore unlikely to be associated with virulence. In addition, we used genotype-phenotype correlation and CRISPR-Cas9 editing to identify a genome variant that results in the inability of one isolate to utilize certain branched-chain amino acids as a sole nitrogen source.

Emergence of clonal fluconazole-resistant Candida parapsilosis clinical isolates in a multicentre laboratory-based surveillance study in India

OBJECTIVES

The emergence of fluconazole resistance in Candida parapsilosis healthcare-associated infections has recently been increasingly reported. Antifungal susceptibility profiles and mechanisms of fluconazole resistance in C. parapsilosis (n = 199) from nine hospitals in India collected over a period of 3 years were studied. Further, clonal transmission of fluconazole-resistant isolates in different hospitals was investigated.

METHODS

Antifungal susceptibility testing of five azoles, amphotericin B and 5-flucytosine was performed by the CLSI microbroth dilution method. The azole target ERG11 gene was sequenced, and the significance of a novel ERG11 mutation in C. parapsilosis was determined using a gap-repair cloning approach in Saccharomyces cerevisiae. In addition, microsatellite analysis was performed to determine the clonal lineage of C. parapsilosis-resistant strains circulating among different hospitals.

RESULTS

A total of 64 (32%) C. parapsilosis isolates were non-susceptible to fluconazole, which included resistant (n = 55; MIC >4 mg/L) and susceptible dose-dependent (n = 9) isolates. Of these 64 non-susceptible isolates, a novel K143R amino acid substitution was noted in 92%, and the remaining five isolates had the Y132F substitution. Elevated azole MICs (≥16-fold) were detected in S. cerevisiae upon expression of C. parapsilosis ERG11 alleles carrying Y132F or K143R substitutions. Two major clusters of non-susceptible isolates were circulating in seven Indian hospitals.

CONCLUSIONS

We report a novel K143R amino acid substitution in ERG11p causing fluconazole resistance in C. parapsilosis. Fluconazole-non-susceptible C. parapsilosis isolates carrying the novel K143R amino acid substitution should be identified in clinical microbiology laboratories to prevent further clonal transmission.

Duration of antifungal therapy for septic pulmonary embolism caused by Candida albicans from a central venous catheter: A case report

The treatment duration for candidemia with septic pulmonary embolism should be determined based on the clearance of fungus from the bloodstream and improvement of symptoms. The remaining lung nodules may not necessarily indicate persistent infection.

A seven-year surveillance of Candida bloodstream infection at a university hospital in KSA

Objectives

Candidemia incidence has increased in the past few years, with high mortality. Previous studies have reported a variable distribution of Candida spp. among different regions. This study aimed to identify the species found in Candida bloodstream infections, routine antifungal susceptibility testing, and mortality outcomes in an academic medical centre.

Methods

Between January 2012 and December 2018, the positive blood cultures for candidemia infection were retrieved and statistically analysed for species prevalence, susceptibility pattern, and crude mortality at 14, 30, 60 and 90 days.

Results

Of 156 candidemia cases, a majority (69.2%) was caused by non-albicans Candida spp. After Candida albicans (30.8%), Candida tropicalis and Candida parapsilosis were the second and third most frequeunt isolates spp, each counting for 23.7%. Acquired resistance was detected in 14.8% of candidemia strains. No other antifungal resistance was detected. The overall crude mortality rates of all species were 29.3%, 47.9%, 56.4%, and 58.0% at 14, 30, 60, and 90 days, respectively. A higher mortality rate was noted in cases of Candida krusei infection (crude mortality 71.4–100%, p = 0.002).

Conclusion

In this study, a considerable shift to non-albicans Candida causing most bloodstream infections was observed. As such infections pose a serious threat to hospitalised patients, microbiology laboratories are urged to adopt rapid diagnostic and minimal inhibitory concentration-based testing for the detection of susceptible dose-dependent phenotypes. Prospective studies are essential to consider the prognosis of bloodstream infections by various Candida species in a multivariate model.

Coexistence of Pseudomonas aeruginosa With Candida albicans Enhances Biofilm Thickness Through Alginate-Related Extracellular Matrix but Is Attenuated by N-acetyl-l-cysteine

Bacteria and Candidaalbicans are prominent gut microbiota, and the translocation of these organisms into blood circulation might induce mixed-organism biofilms, which warrants the exploration of mixed- versus single-organism biofilms in vitro and in vivo. In single-organism biofilms, Acinetobacter baumannii and Pseudomonas aeruginosa (PA) produced the least and the most prominent biofilms, respectively. C. albicans with P. aeruginosa (PA+CA) induced the highest biofilms among mixed-organism groups as determined by crystal violet straining. The sessile form of PA+CA induced higher macrophage responses than sessile PA, which supports enhanced immune activation toward mixed-organism biofilms. In addition, Candida incubated in pre-formed Pseudomonas biofilms (PA>CA) produced even higher biofilms than PA+CA (simultaneous incubation of both organisms) as determined by fluorescent staining on biofilm matrix (AF647 color). Despite the initially lower bacteria during preparation, bacterial burdens by culture in mixed-organism biofilms (PA+CA and PA>CA) were not different from biofilms of PA alone, supporting Candida-enhanced Pseudomonas growth. Moreover, proteomic analysis in PA>CA biofilms demonstrated high AlgU and mucA with low mucB when compared with PA alone or PA+CA, implying an alginate-related mucoid phenotype in PA>CA biofilms. Furthermore, mice with PA>CA biofilms demonstrated higher bacteremia with more severe sepsis compared with mice with PA+CA biofilms. This is possibly due to the different structures. Interestingly, l-cysteine, a biofilm matrix inhibitor, attenuated mixed-organism biofilms both in vitro and in mice. In conclusion, Candida enhanced Pseudomonas alginate–related biofilm production, and Candida presentation in pre-formed Pseudomonas biofilms might alter biofilm structures that affect clinical manifestations but was attenuated by l-cysteine.

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

OBJECTIVE

This 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.

METHODS

A total of 223 positive blood cultures for yeasts were retrospectively reported during the period April 2010-April 2020.

RESULTS

Ninety-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.

DISCUSSION

Fungemia remain frequent hospital infections associated with high mortality in Mayotte. The vast majority of fungemia was due to Candida spp. Non-albicansCandida 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.

Clinical characteristics, risk factors and outcomes of mixed Candida albicans/bacterial bloodstream infections

Purpose

The purpose of this study was to explore the clinical features, risk factors, and outcomes of mixed Candida albicans/bacterial bloodstream infections (mixed-CA/B-BSIs) compared with monomicrobial Candida albicans bloodstream infection (mono-CA-BSI) in adult patients in China.

Methods

All hospitalized adults with Candida albicans bloodstream infection (CA-BSI) were recruited for this retrospective observational study from January 1, 2013, to December 31, 2018.

Results

Of the 117 patients with CA-BSI, 24 patients (20.5%) had mixed-CA/B-BSIs. The most common copathogens were coagulase-negative Staphylococcus (CNS) (24.0%), followed by Klebsiella pneumoniae (20.0%) and Staphylococcus aureus (16.0%). In the multivariable analysis, a prior ICU stay > 2 days (adjusted odds ratio [OR], 7.445; 95% confidence interval [CI], 1.152–48.132) was an independent risk factor for mixed-CA/B-BSIs. Compared with patients with mono-CA-BSI, patients with mixed-CA/B-BSIs had a prolonged length of mechanical ventilation [17.5 (4.5, 34.8) vs. 3.0 (0.0, 24.5), p = 0.019] and prolonged length of ICU stay [22.0 (14.3, 42.2) vs. 8.0 (0.0, 31.5), p = 0.010]; however, mortality was not significantly different.

Conclusions

There was a high rate of mixed-CA/B-BSIs cases among CA-BSI cases, and CNS was the predominant coexisting species. A prior ICU stay > 2 days was an independent risk factor for mixed -CA/B-BSIs. Although there was no difference in mortality, the outcomes of patients with mixed -CA/B-BSIs, including prolonged length of mechanical ventilation and prolonged length of ICU stay, were worse than those with mono-CA-BSI; this deserves further attention from clinicians.

Clinical Features and Mortality of Nosocomial Candidemia in Very Old Patients: A Multicentre Italian Study

INTRODUCTION

Being elderly is a well-known risk factor for candidemia, but few data are available on the prognostic impact of candidemia in the very old (VO) subjects, as defined as people aged ≥75 years.

OBJECTIVE

The aim of this study was to assess risk factors for nosocomial candidemia in two groups of candidemia patients, consisting of VO patients (≥75 years) and adult and old (AO) patients (18-74 years). In addition, risk factors for death (30-day mortality) were analysed separately in the two groups.

METHODS

We included all consecutive candidemia episodes from January 2011 to December 2013 occurring in six referral hospitals in north-eastern Italy.

RESULTS

A total of 683 nosocomial candidemia episodes occurred. Of those, 293 (42.9%) episodes were in VO and 390 (57.1%) in AO patients. Hospitalization in medical wards, chronic renal failure, urinary catheter, and peripheral parenteral nutrition (PPN) were more common in VO than in AO patients. In the former patient group, adequate antifungal therapy (73.2%) and central venous catheter (CVC) removal (67.6%) occurred less frequently than in AO patients (82.5 and 80%, p < 0.002 and p < 0.004, respectively). Thirty-day mortality was higher in VO compared to AO patients (47.8 vs. 23.6%, p < 0.0001). In AO patients, independent risk factors for death were age (OR 1.04, 95% CI 1.00-1.09, p = 0.038), recent history of chemotherapy (OR 22.01, 95% CI 3.12-155.20, p = 0.002), and severity of sepsis (OR 40.68, 95% CI 7.42-223.10, p < 0.001); CVC removal was associated with higher probability of survival (OR 0.10, 95% CI 0.03-0.33, p < 0.001). In VO patients, independent risk factors for death were PPN (OR 3.5, 95% CI 1.17-10.47, p = 0.025) and hospitalization in medical wards (OR 2.58, 95% CI 1.02-6.53, p = 0.046), while CVC removal was associated with improved survival (OR 0.40, 95% CI 0.16-1.00, p = 0.050).

CONCLUSION

Thirty-day mortality was high among VO patients and was associated with inadequate management of candidemia, especially in medical wards.

Molecular Methods for the Diagnosis of Invasive Candidiasis

Invasive infections caused by members of the genus Candida are on the rise. Especially patients in intensive care units, immunocompromised patients, and those recovering from abdominal surgery are at risk for the development of candidemia or deep-seated candidiasis. Rapid initiation of appropriate antifungal therapy can increase survival rates significantly. In the past, most of these infections were caused by C. albicans, a species that typically is very susceptible to antifungals. However, in recent years a shift towards infections caused by non-albicans species displaying various susceptibly patterns has been observed and the prompt diagnosis of the underlying species has become an essential factor determining the therapeutic outcome. The gold standard for diagnosing invasive candidiasis is blood culture, even though its sensitivity is low and the time required for species identification usually exceeds 48 h. To overcome these issues, blood culture can be combined with other methods, and a large number of tests have been developed for this purpose. The aim of this review was to give an overview on strengths and limitations of currently available molecular methods for the diagnosis of invasive candidiasis.

Candida isolates causing candidemia show different degrees of virulence in Galleria mellonella

We aim to assess intra- and interspecies differences in the virulence of Candida spp. strains causing candidemia using the invertebrate Galleria mellonella model. We studied 739 Candida spp. isolates (C. albicans [n = 373], C. parapsilosis [n = 203], C. glabrata [n = 92], C. tropicalis [n = 53], and C. krusei [n = 18]) collected from patients with candidemia admitted to Gregorio Marañon Hospital (Madrid, Spain). Species-specific infecting inocula (yeast cells/larva) were adjusted (5 × 105 [C. albicans, and C. tropicalis], 2 × 106-5 × 106 [C. parapsilosis, C. glabrata, and C. krusei]) and used to infect 10 larvae per isolate; percentage of survival and median survival per isolate were calculated. According to the interquartile range of the median survival, isolates with a median survival under P25 were classified as of high-virulence and isolates with a median survival over P75 as of low virulence. The median survival of larvae infected with different species was variable: C. albicans (n = 2 days, IQR <1-3 days), C. tropicalis (n = 2 days, IQR 1.5-4 days), C. parapsilosis (n = 2 days, IQR 2-3.5 days), C. glabrata (n = 3 days, IQR 2-3 days), and C. krusei (n = 7 days, 6.5->8 days) (P < .001). Differences in virulence among species were validated by histological examination (day +1 post-infection) in the larvae infected by the isolates of each virulence category and species. Virulence-related gene expression in C. albicans isolates did not reach statistical significance. We report species-specific virulence patterns of Candida spp. and show that isolates within a given species have different degrees of virulence in the animal model.

Microbes and Cancer: Friends or Faux?

Cancer is one of the most aggressive and deadly diseases in the world, representing the second leading cause of death. It is a multifactorial disease, in which genetic alterations play a key role, but several environmental factors also contribute to its development and progression. Infections induced by certain viruses, bacteria, fungi and parasites constitute risk factors for cancer, being chronic infection associated to the development of certain types of cancer. On the other hand, susceptibility to infectious diseases is higher in cancer patients. The state of the host immune system plays a crucial role in the susceptibility to both infection and cancer. Importantly, immunosuppressive cancer treatments increase the risk of infection, by decreasing the host defenses. Furthermore, alterations in the host microbiota is also a key factor in the susceptibility to develop cancer. More recently, the identification of a tumor microbiota, in which bacteria establish a symbiotic relationship with cancer cells, opened a new area of research. There is evidence demonstrating that the interaction between bacteria and cancer cells can modulate the anticancer drug response and toxicity. The present review focuses on the interaction between microbes and cancer, specifically aiming to: (1) review the main infectious agents associated with development of cancer and the role of microbiota in cancer susceptibility; (2) highlight the higher vulnerability of cancer patients to acquire infectious diseases; (3) document the relationship between cancer cells and tissue microbiota; (4) describe the role of intratumoral bacteria in the response and toxicity to cancer therapy.

Human inborn errors of immunity underlying superficial or invasive candidiasis

Candida species, including C. albicans in particular, can cause superficial or invasive disease, often in patients with known acquired immunodeficiencies or iatrogenic conditions. The molecular and cellular basis of these infections in patients with such risk factors remained largely elusive, until the study of inborn errors of immunity clarified the basis of the corresponding inherited and "idiopathic" infections. Superficial candidiasis, also known as chronic mucocutaneous candidiasis (CMC), can be caused by inborn errors of IL-17 immunity. Invasive candidiasis can be caused by inborn errors of CARD9 immunity. In this chapter, we review both groups of inborn errors of immunity, and discuss the contribution of these studies to the deciphering of the critical mechanisms of anti-Candida immunity in patients with other conditions.

Candida bloodstream infection in patients with systemic autoimmune diseases

OBJECTIVES

To describe the epidemiological, clinical and microbiological characteristics and mortality of patients with Candida bloodstream infection and systemic autoimmune diseases.

METHODS

We performed a retrospective multicenter study of candidemia in adults with systemic autoimmune diseases between 2010 and 2016.

RESULTS

Among 1040 patients with candidemia, 36 (3.5%) had a systemic autoimmune disease. The most common systemic autoimmune disease was rheumatoid arthritis (27.8%). The most common species was Candida albicans (66.7%). Twenty-two (61.1%) patients received a corticosteroid therapy and nine (25%) received an immunosuppressive therapy at the time of candidemia. The mortality rate was 27.8%.

CONCLUSIONS

Systemic autoimmune diseases are not common in patients with candidemia. The unadjusted mortality rate was comparable to other candidemia studies in the general population.

Candida spp./Bacteria Mixed Biofilms

The ability to form biofilms is a common feature of microorganisms, such as bacteria or fungi. These consortiums can colonize a variety of surfaces, such as host tissues, dentures, and catheters, resulting in infections highly resistant to drugs, when compared with their planktonic counterparts. This refractory effect is particularly critical in polymicrobial biofilms involving both fungi and bacteria. This review emphasizes Candida spp.-bacteria biofilms, the epidemiology of this community, the challenges in the eradication of such biofilms, and the most relevant treatments.

Candidemia in a public hospital in Northeastern Brazil: Epidemiological features and risk factors in critically ill patients

BACKGROUND

Candidemia is a life-threatening fungal infection characterized by the presence of Candida in the blood.

AIMS

To describe the clinical-epidemiological features and main risk factors among patients with candidemia admitted to Intensive Care Unit.

METHODS

A cross-sectional, retrospective and observational study was performed between January 2015 and July 2016. Laboratory reports and medical records from ICU patients admitted to a public hospital in northeastern Brazil were analyzed.

RESULTS

There were 1573 admissions and 67 of them were positive for candidemia. The majority of patients were male (53.3%) and remained at the hospital for more than seven days (86.6%). Non-C. albicansCandida infections (60%) were predominant. Broad-spectrum antibiotic therapy was prescribed in 98.4% of the cases. The most frequent underlying diseases were sepsis (73.3%), presence of solid tumors (15%), respiratory condition (60%), urinary tract disease (56.6%) and gastrointestinal tract diseases (23.3%). Surgeries were carried out on 43% of the patients, consisting of 23.3% abdominal surgeries, with a mortality rate of 92.8%. Risk factors were venous central access (93.3%), mechanical ventilation (81.6%), nasoenteral tube (83.3%), nasogastric tube (25%), indwelling bladder catheter (88.3%), diabetes mellitus (55%) and tracheostomy (36.6%). Statistical analysis correlated the use of indwelling bladder catheter with a higher mortality rate (r=0.07412, p=0.0353).

CONCLUSIONS

The current study reveals the high case fatality rates among critically ill patients suffering from candidemia admitted to ICU. Herein, we highlight the importance of identifying non-C. albicansCandida species and reinforce the idea of carrying out epidemiological surveillances and antifungal susceptibility tests.

Biomarkers of fungal infection: Expert opinion on the current situation

The introduction of non-culture-based diagnostic techniques is revolutionizing the world of microbiological diagnosis and infection assessment. Fungi are no exception, and the introduction of biomarkers has opened up enormous expectations for better management of these entities. Biomarkers are diverse, their targets are also diverse and their evaluation has been done preferably in an individualized use and with deficient designs. Less is known about the value of the combined use of biomarkers and the impact of the negativity of two or more biomarkers on antifungal treatment decisions has been poorly studied. Given the paucity of prospective, randomized and definitive studies, we have convened experts from different fields, with an interest in invasive fungal infections, to answer some questions about the current relevant use of fungal biomarkers. This document summarizes the answers of these experts to the different questions.

Aspergillus diversity in the environments of nosocomial infection cases at a university hospital

Aspergillus species (sp.) that causes opportunistic infections have been increasingly found in human mainly immunosuppressive patients around the world every year. The main objective was to use a rapid and cheap molecular method for monitoring Aspergillus infections and epidemiological approaches. In order to identity Aspergilli species (spp.), a number of molecular methods including restriction fragment length polymorphism (RFLP) have been employed in accordance with ribosomal RNA amplification. The focus of this study — a group of hospitalized patients with clinical and subclinical signs of infection. All of the collected clinical specimens were transported to the medical mycology lab and examined for Aspergillus identification. The environmental specimens were collected from air and surfaces inspected for the Aspergillus within the hospital sources. At first, growth characteristics and microscopic features on mycological media for the identification of Aspergillus sp. were performed. For the confirmation of Aspergillus isolates which similarly found in clinical and environmental sources, molecular method polymerase chain reaction/restriction fragment length polymorphism was carried out. From the mentioned specimens, 102 fungal isolates included Candida spp., Aspergillus spp. and other fungi. Aspergillus flavus (47%), Aspergillus fumigatus (29.4%) and Aspergillus niger (23.5%) all were found as the most common clinical isolates. In addition, Aspergillus isolates from environmental were Aspergillus niger (43.7%), Aspergillus flavus (41.7%), Aspergillus fumigatus (14.6%). Therefore, polymerase chain reaction-restriction fragment length polymorphism with a single restriction enzyme can be very useful in the identification of Aspergillus spp., because of its facility in use, speed, robust, and high sensitivity of diagnosis.

To study the profile of Candida isolates and antifungal susceptibility pattern of neonatal sepsis in a tertiary care hospital of North India

AIMS AND OBJECTIVE

To study the profile of Candida infection and antifungal susceptibility (AFS) pattern in neonatal sepsis.

MATERIALS AND METHODS

In this prospective observational study, 850 blood samples were collected and processed from neonates who were suspected clinically to have sepsis. The blood culture that showed growth of Candida was further processed for species identification. Antifungal susceptibility was done as per the National Committee for Clinical Laboratory Standards (NCCLS)/Clinical Laboratory Standards Institute (CLSI) M44-A-2 guidelines by disc diffusion method and automated vitek-2 compact system. Candidemia was diagnosed by isolation of Candida species from at least one positive blood culture containing pure growth of Candida species with supportive clinical features.

RESULTS

Candida species were isolated in 32 specimens of the total 322 culture-positive cases. The most common isolate was Candida tropicalis (14/32; 43.75%) followed by Candida albicans (7/32; 21.87%) and Candida glabrata (6/32; 18.75%). The three most common neonatal risk factors for candidemia were low birth weight, prolonged use of intravenous antibiotics and presence of central venous line. Non-albicans Candida (NAC) showed good sensitivity to fluconazole as compared to Candida albicans. The fluconazole sensitivity of Candida tropicalis, Candida glabrata, and Candida parapsilosis was 93, 67, and 100%, respectively, whereas it was 57% in Candida albicans. The sensitivity to amphotericin B was 95% among all Candida isolates. All NAC were sensitive to amphotericin B, while only 72% Candida albicans were sensitive to amphotericin B.

CONCLUSIONS

The incidence of neonatal sepsis secondary to NAC is increasing and has replaced Candida albicans as a major cause of neonatal fungal sepsis. Low birth weight is the most important risk factor for Candida sepsis. The resistance of Candida albicans is increasing for both fluconazole and amphotericin B when compared to NAC. Increasing antifungal resistance warrants its judicious use both for prophylaxis and treatment.

Clinical impacts of delayed central venous catheter removal according to the severity of comorbidities in patients with candidaemia

BACKGROUND

The effects of early central venous catheter (CVC) removal on the clinical outcomes of patients with candidaemia remain controversial. This study evaluated the impact of delayed CVC removal on mortality according to the severity of comorbidities in patients with candidaemia.

METHODS

Patients with candidaemia in a tertiary care hospital between January 2010 and December 2017 were included retrospectively. The severity of comorbidities was classified as low [Charlson Comorbidity Index (CCI) score ≤3] or high (CCI score ≥4). Cases with removal of CVC >2 days after the onset of candidaemia or without CVC removal were classified as having delayed CVC removal.

RESULTS

In total, 239 patients with candidaemia were included, excluding 18 who died within 2 days of onset of candidaemia. Of these, 149 had low CCI scores and 90 had high CCI scores. Septic shock [adjusted odds ratio (aOR)=9.5] and delayed CVC removal (aOR=4.7) were significantly associated with increased 30-day mortality, whereas Candida parapsilosis infection (aOR=0.2) and cerebrovascular disease (aOR=0.3) were associated with decreased 30-day mortality, in patients with low CCI scores. Septic shock (aOR=13.0) was the only risk factor for 30-day mortality in those with high CCI scores. Delayed CVC removal was associated with increased 30-day mortality in patients with low CCI scores (50.0% vs 20.3%; P=0.001), but not in those with high CCI scores (50.0% vs 47.9%; P=0.87).

CONCLUSION

Early CVC removal may improve the survival of patients with candidaemia and low CCI scores, but no such protective effect was evident in those with high CCI scores.

Initial Antifungal Strategy Reduces Mortality in Critically Ill Patients With Candidemia: A Propensity Score-Adjusted Analysis of a Multicenter Study

OBJECTIVE

The objective of this study was to evaluate the impact of the empirical therapy with fluconazole or an echinocandin on 30- and 90-day mortality in critically ill patients with candidemia. The outcome of patients in whom the empirical echinocandin was deescalated to fluconazole was also assessed.

DESIGN

Retrospective, observational multicenter study.

SETTING

Medical and surgical ICUs in nine Spanish hospitals.

PATIENTS

Adult patients (≥ 18 yr) with an episode of Candida bloodstream infection during ICU admission from January 2011 to April 2016.

INTERVENTIONS

Patient characteristics, infection-related variables, therapeutic interventions, and metastatic complications were reviewed. A propensity score-adjusted multivariable analysis was performed to identify the risk factors significantly associated with 30-day and 90-day mortality.

MEASUREMENTS AND MAIN RESULTS

A total of 294 patients were diagnosed of candidemia in the participant ICUs. Sixty patients were excluded (other antifungals in the primary therapy or the patient died without empirical antifungal therapy). The study group comprised 115 patients who received fluconazole (30-day mortality, 37.4%) and 119 patients treated empirically with an echinocandin (30-day mortality, 31.9%). The use of an echinocandin in the empirical therapy was a protective factor for 30-day (odds ratio, 0.32; 95% CI, 0.16-0.66; p = 0.002) and 90-day mortality (odds ratio, 0.50; 95% CI, 0.27-0.93; p = 0.014) in the propensity score- adjusted multivariable analysis. Deescalation of the empirical echinocandin to fluconazole was not associated with a higher mortality or the occurrence of long-term complications.

CONCLUSIONS

Empirical use of an echinocandin in critically ill patients with documented candidemia reduces mortality at 30 and 90 days significantly. Deescalation of the empirical echinocandin to fluconazole is safe and effective in fluconazole-susceptible 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.

Appropriate use of antifungals: impact of an antifungal stewardship program on the clinical outcome of candidaemia in a French University Hospital

OBJECTIVES

The objective of this study was to compare clinical outcomes of patients with candidaemia before and after implementation of an antifungal stewardship program (AFSP).

METHODS

This study included all consecutive cases of candidaemia identified from January 2012 to December 2015 in a French University Hospital. Data were collected retrospectively for a period of 2 years before implementation of the AFSP, and prospectively for 2 years after. All cases were reviewed by a multidisciplinary panel of experts including infectiologists, a microbiologist and pharmacists to have a complete follow-up of patients.

RESULTS

33 and 37 patients were finally included in the first and second period, respectively. The sites of entry of the candidaemia cases studied were as follows: intraabdominal in 29 cases (41.4%), central venous catheter 21 (30.0%), other or unknown: 20 (28.6%). Infectiologist consultations increased from 36.4 to 86.5% between the two periods with a significative impact on daily blood cultures which were more frequently performed in the second period (p = 0.04), and the use of echinocandins which was more frequent in the second period (97.1% of cases vs 78.8%, p = 0.03). The 3-month mortality rate declined from 36.4% in the first period to 27.0% in the second period (p = 0.4).

CONCLUSIONS

Despite the insufficient number of candidaemia cases and the presence of other unmodifiable risk factors of mortality which did not allow us to show a significant effect on the 3-month mortality, AFSP had a significant effect on daily blood cultures and echinocandin use as first-line therapy.

Mortality and risk factor analysis for Candida blood stream infection: A multicenter study

Candida blood stream infection (candidemia) is severe systemic infection mainly develops after intensive medical cares. The mortality of candidemia is affected by the underlying conditions, causative agents and the initial management. We retrospectively analyzed mortality-related risk factors in cases of candidemia between April 2011 and March 2016 in five regional hospitals in Japan. We conducted bivariate and multivariate analysis of factors including causative Candida species, patients' predisposing conditions, and treatment strategies, such as empirically selected antifungal drug and time to appropriate antifungal treatment, to elucidate their effects on 30-day mortality. The study enrolled 289 cases of candidemia in adults. Overall 30-day mortality was 27.7%. Forty-nine cases (17.0%) were community-acquired. Bivariate analysis found advanced age, high Sequential Organ Failure Assessment (SOFA) score, and prior antibiotics use as risk factors for high mortality; however community-acquired candidemia, C. parapsilosis candidemia, obtaining follow-up blood culture, and empiric treatment with fluconazole were associated with low mortality. Logistic regression revealed age ≥65 years (adjusted odds ratio, 2.13) and sequential organ failure assessment (SOFA) score ≥6 (6.30) as risk factors for 30-day mortality. In contrast, obtaining follow-up blood culture (0.38) and empiric treatment with fluconazole (0.32) were found to be protective factors. The cases with candidemia in associated with advanced age and poor general health conditions should be closely monitored. Obtaining follow-up blood culture contributed to an improved prognosis.

Impact of empirical treatment with antifungal agents on survival of patients with candidemia

OBJECTIVE

The objective of this study was to evaluate the impact of echinocandins and fluconazole) on mortality 7 and 30 days after candidemia onset and overall in-hospital mortality), in patients with candidemia at a Spanish tertiary hospital.

METHODS

A retrospective study was conducted that enrolled all non-neutropenic adult patients diagnosed with candidemia at Hospital Clínico Universitario de Valladolid between 2007 and 2016. A total of 179 patients were evaluated, they were divided into two sub-groups: surviving patients (n = 92) and non-surviving patients (n = 87).

RESULTS

The 7-day mortality was 25,1% (45), 30-day mortality was 46,9% (84), and overall in-hospital mortality was 48,6% (87). 40.8% of patients received no antifungal treatment (43.8% of surviving patients and 37.8% of non-surviving patients; p=0.15). A total of 106 (59.2%) patients were treated, of which 90 patients (50.3%) received empiric treatment. 19.6% and 47.8% of surviving patients were treated with echinocandins and fluconazole, respectively. By contrast, of non-surviving patients, 31.0% were treated with echinocandins and 47.1% received fluconazole. Survival for the first 7 days was significantly higher in treated with antifungal agents (log-rank = 0.029), however, there were not significant differences in 30-day survival. Factors linked to a significant increase in overall in-hospital mortality were age (OR 1.040), septic shock (OR 2.694) and need for mechanical ventilation > 48 h (OR 2.812).

CONCLUSIONS

Patients who received antifungal treatment, regardless of whether they received fluconazole or echinocandins, had a significantly lower mortality rate after 7 days than untreated patients, although no significant differences in 30-day mortality were seen.

Influence of subinhibitory antifungal concentrations on extracellular hydrolases and biofilm production by Candida albicans recovered from Egyptian patients

BACKGROUND

Extracellular hydrolases (phospholipase, aspartyl protease and haemolysin) and biofilm production are considered as major virulence factors of the opportunistic pathogenic fungus Candida albicans. However, the impact of antifungal therapy on such virulence attributes is not well investigated. The common antifungal agents may disturb the production of secreted hydrolases as well as biofilm formation. Accordingly, this study addressed the effect of subinhibitory concentrations (sub-MICs) of selected antifungal agents on some virulence factors of C. albicans clinical isolates.

METHODS

C. albicans isolates (n = 32) were recovered from different clinical samples and their identification was confirmed to the species level. Antifungal susceptibility profiles of isolates were determined against (nystatin, fluconazole and micafungin) and minimum inhibitory concentrations (MICs) were interpreted according to Clinical and Laboratory Standards Institute guidelines. Virulence determinants comprising secreted hydrolases (phospholipase, aspartyl protease and haemolysin) and biofilm formation were investigated in the presence of the sub-MICs of the tested antifungal agents.

RESULTS

Treatment of clinical C. albicans isolates with subinhibitory nystatin, fluconazole and micafungin concentrations significantly decreased production of extracellular hydrolases. Nystatin had the greatest inhibitory effect on phospholipase and aspartyl protease production. However, micafungin showed the highest reducing effect on the hemolytic activity of the treated clinical isolates. Moreover, nystatin and micafungin, but not fluconazole, had a noticeable significant impact on inhibiting biofilm formation of C. albicans clinical isolates.

CONCLUSION

Our findings highlighted the significant influences of commonly prescribed antifungal agents on some virulence factors of C. albicans. Accordingly, antifungal therapy may modulate key virulence attributes of C. albicans.