Impact of antifungal prophylaxis on colonization and azole susceptibility of Candida species

Oral Candida carriage and resistance against common antifungal agents in hematopoietic stem cell transplantation recipients

PURPOSE

Allogeneic hematopoietic stem cell transplant (HSCT) recipients receiving long-term and high-dose immunosuppressive medications suffer commonly from oral candida infections. This prospective cohort study examined oral fungal carriage in HSCT recipients and screened the susceptibility against commonly used antifungal agents. An increasing oral occurrence of Candida spp. and the development of resistance against clinically administered fluconazole were hypothesized.

METHODS

Two hundred HSCT recipients were included and followed up for 2 years post-HSCT. Oral microbiological specimens were analyzed with matrix-assisted laser desorption/ionization-time of flight mass spectrometry assays (MALDI-TOF). The colorimetric method was applied for the susceptibility testing by commercially available Sensititre YeastOne (SYO®, TREK Diagnostics Systems, Thermo-Fisher, UK).

RESULTS

The prevalence of oral Candida spp. carriage increased statistically significantly after a year post-HSCT being 30, 26, 35, 44, and 47%, pre-HSCT, 3, 6, 12, and 24 months post-HSCT, respectively. Altogether, 169 clinical oral Candida strains were isolated. Fourteen Candida spp. were identified, and C. albicans was predominant in 74% of the isolates pre-HSCT with a descending prevalence down to 44% 2 years post-HSCT. An increasing relative proportion of non-albicans species post-HSCT was evident. No development of resistance of C. albicans against fluconazole was found. Instead, a shift from C. albicans towards non-albicans species, especially C. dubliensis, C. glabrata, and relatively seldom found C. krusei, was observed.

CONCLUSION

Oral Candida carriage increases after HSCT. Instead of the expected development of resistance of C. albicans against fluconazole, the relative proportion of non-albicans strains with innate resistance against azole-group antifungals increased.

Opportunistic Infections in Patients Receiving Post-Transplantation Cyclophosphamide: Impact of Haploidentical versus Unrelated Donor Allograft

Post-transplantation cyclophosphamide (PTCy) is an effective strategy for graft-versus-host disease (GVHD) prophylaxis and is the standard of care for haploidentical hematopoietic cell transplantation (HCT). It is increasingly used for matched and mismatched unrelated donor (MUD/MMUD) HCT, but infections remain a concern. The objective of this study was to evaluate the characteristics and risk factors for infections in haploidentical and unrelated donor HCT recipients treated with PTCy-based GVHD prophylaxis. This single-center retrospective study examined 354 consecutive adults undergoing HCT with PTCy-based GVHD prophylaxis (161 MUD/MMUD; 193 haploidentical) between 2015 and 2022. Opportunistic infections (OIs), including cytomegalovirus (CMV), adenovirus (AdV), Epstein-Barr virus (EBV), and invasive fungal disease (IFD), were assessed from day 0 through day +365. The 1-year cumulative incidence functions of OIs and nonrelapse mortality (NRM) were calculated using dates of relapse and repeat HCT as competing risks. Secondary analysis evaluated risk factors for OIs and NRM using univariate and multivariable Cox regression models. Haploidentical HCT recipients had an increased risk of OIs compared to unrelated donor allograft recipients (39% for haploidentical versus 25% for MUD/MMUD; hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.16 to 2.49; P = .006). On multivariable analysis, haploidentical donor (HR, 1.50; 95% CI, 1.01 to 2.23; P = .046), prior HCT (HR, 1.99; 95% CI, 1.29 to 3.09; P = .002), and diagnosis of aGVHD (HR, 1.47; 95% CI, 1.02 to 2.14; P = .041) were associated with increased risk of OIs. NRM within the first year was not significantly different between the 2 cohorts (HR, 1.11; 95% CI, .64 to 1.93; P = .70). Overall, haploidentical donor was a significant risk factor for OIs in patients receiving PTCy, although 1-year NRM was not different between haploidentical HCT and MUD/MMUD HCT recipients. CMV and AdV infections were significantly increased among haploidentical HCT recipients, whereas the incidences of EBV infection and IFD were similar in the 2 cohorts. Our findings may have implications for infection monitoring and prophylaxis in the setting of PTCy, particularly in haploidentical HCT recipients.

Fungemia in Hospitalized Adult Patients with Hematological Malignancies: Epidemiology and Risk Factors

Fungemia in hematologic malignancies (HM) has high mortality. This is a retrospective cohort of adult patients with HM and fungemia between 2012 and 2019 in institutions of Bogotá, Colombia. The epidemiological, clinical, and microbiological characteristics are described, and risk factors related to mortality are analyzed. One hundred five patients with a mean age of 48 years (SD 19.0) were identified, 45% with acute leukemia and 37% with lymphomas. In 42%, the HM was relapsed/refractory, 82% ECOG > 3, and 35% received antifungal prophylaxis; 57% were in neutropenia, with an average duration of 21.8 days. In 86 (82%) patients, Candida spp. was identified, and other yeasts in 18%. The most frequent of the isolates were non-albicans Candida (61%), C. tropicalis (28%), C. parapsilosis (17%), and C. krusei (12%). The overall 30-day mortality was 50%. The survival probability at day 30 in patients with leukemia vs. lymphoma/multiple myeloma (MM0 group was 59% (95% CI 46-76) and 41% (95% CI 29-58), p = 0.03, respectively. Patients with lymphoma or MM (HR 1.72; 95% CI 0.58-2.03) and ICU admission (HR 3.08; 95% CI 1.12-3.74) were associated with mortality. In conclusion, in patients with HM, non-albicans Candida species are the most frequent, and high mortality was identified; moreover, lymphoma or MM and ICU admission were predictors of mortality.

Invasive Yeast Infection After Haploidentical Donor Hematopoietic Cell Transplantation Associated with Cytokine Release Syndrome

BACKGROUND

Use of haploidentical donor hematopoietic cell transplantation (haploHCT) has expanded but recent reports raise concern for increased rates of infectious complications. The incidence and risk factors for invasive fungal disease (IFD) after haploHCT have not been well elucidated.

OBJECTIVE

The objective of this study is to evaluate the incidence and risk factors for IFD after haploHCT. The identification of key risk factors will permit targeted prevention measures and may explain elevated risk for other infectious complications after haploHCT.

STUDY DESIGN

We performed a single-center retrospective study of all adults undergoing haploHCT between May 2011 and May 2021 (n=205). The 30-day and one-year cumulative incidence of proven or probable IFD and one-year non-relapse mortality (NRM) were assessed. Secondary analysis evaluated risk factors for invasive yeast infection (IYI) using univariate and multivariable Cox regression models.

RESULTS

Twenty-nine patients (14%) developed IFD following haploHCT. Nineteen (9.3%) developed IYI in the first year, 13 of which occurred early with a 30-day cumulative incidence of 6.3% (95% CI 2.9 - 9.6%) and increased NRM in patients with IYI (53.9% versus 10.9%). The majority of yeast isolates (17/20; 85%) were fluconazole susceptible. The incidence of IYI in the first 30 days after haploHCT was 10% among the 110 (54%) patients who developed cytokine release syndrome (CRS) and 21% among the 29 (14%) who received tocilizumab. On multivariable analysis, AML (HR 6.24; 1.66 - 23.37; p=0.007) and CRS (HR 4.65; 1.00 - 21.58; p=0.049) were associated with an increased risk of early IYI after haploHCT.

CONCLUSION

CRS after haploHCT is common and is associated with increased risk of early IYI. The identification of CRS as a risk factor for IYI raises questions about its potential association with other infections after haploHCT. Recognition of key risk factors for infection may permit individualized strategies for prevention and intervention and minimize potential side effects.

Augmenting Azoles with Drug Synergy to Expand the Antifungal Toolbox

Fungal infections impact the lives of at least 12 million people every year, killing over 1.5 million. Wide-spread use of fungicides and prophylactic antifungal therapy have driven resistance in many serious fungal pathogens, and there is an urgent need to expand the current antifungal arsenal. Recent research has focused on improving azoles, our most successful class of antifungals, by looking for synergistic interactions with secondary compounds. Synergists can co-operate with azoles by targeting steps in related pathways, or they may act on mechanisms related to resistance such as active efflux or on totally disparate pathways or processes. A variety of sources of potential synergists have been explored, including pre-existing antimicrobials, pharmaceuticals approved for other uses, bioactive natural compounds and phytochemicals, and novel synthetic compounds. Synergy can successfully widen the antifungal spectrum, decrease inhibitory dosages, reduce toxicity, and prevent the development of resistance. This review highlights the diversity of mechanisms that have been exploited for the purposes of azole synergy and demonstrates that synergy remains a promising approach for meeting the urgent need for novel antifungal strategies.

Prognostic factors of Candida spp. bloodstream infection in adults: A nine-year retrospective cohort study across tertiary hospitals in Brazil and Spain

Background

Mortality rates among adults with candidemia vary widely in different geographical settings. Studies directly comparing epidemiology and clinical practices between countries are scarce and could bring insights into improving clinical outcomes.

Methods

Retrospective cohort including adults with candidemia diagnosed in five tertiary hospitals from Brazil and Spain between 2010-2018. Adequate therapeutic management included appropriate antifungal therapy and central-venous-catheter (CVC) removal within 48 h of fungemia. Primary endpoints were mortality rates at 14 and 30 days. Secondary endpoints were prognostic factors associated with 30-day mortality.

Findings

Overall, 720 patients were included, being 323 from Spain. Spanish patients received echinocandins more often (52·5% vs. 39·3%, p = 0.001), initiated antifungals earlier [2 (0-7) vs. 2 days (0-16), p<0.001], and had faster CVC-removal [1 (0-42) vs. 2 days (0-38), p = 0.012]. Mortality was higher among Brazilians at 14 days (35·8% vs. 20·1%, p<0.001), and at 30 days (51·9% vs. 31·6%, p < 0.001). Factors associated with mortality included: age [OR 1·02, 95%CI (1·008-1·032), p = 0·001], neutropenia [OR 3·24, 95%CI (1·594-6·585), p = 0·001], chronic pulmonary disease [OR 2·26, 95%CI (1·495-3·436), p < 0·001], corticosteroids [OR 1·45, 95%CI (1·018-2·079), p = 0·039], Pitt-Score>1 [OR 2·56, 95%CI (1·776-3·690), p < 0·001], and inadequate therapeutic management [OR 2·84, 95%CI (1·685-4·800), p < 0·001]. Being from Spain [OR 0·51, 95%CI (0·359-0·726), p < 0·001] and C. parapsilosis [OR 0·36, 95%CI (0·233-0·568), p < 0·001] were protective.

Interpretation

Higher mortality rates were observed in Brazil. Factors associated with 30-day mortality included mainly epidemiological characteristics and inadequate therapeutic management. Thus, effective and prompt antifungals combined with CVC-removal still need to be emphasized in order to improve the prognosis of adults with candidemia.

Funding

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2017/02203-7); CAPES Foundation (PDSE 88881.187981/2018-01).

Molecular identification and antifungal susceptibility testing of Candida species isolated from oral lesions in patients with head and neck cancer undergoing radiotherapy

Background and Purpose:

Radiation therapy in patients with head and neck malignancies predisposes them to oral Candida colonization and infection due to damage of oral mucosa and destruction of the salivary gland. This study aimed to determine the prevalence of oropharyngeal candidiasis (OPC) in patients with head and neck cancer (HNC) undergoing radiotherapy (RT), identify the yeasts isolated from them, and determine their antifungal susceptibility.

Materials and Methods:

This cross-sectional study was conducted from December 2018 to June 2019 at two referral radiotherapy centers in northern Iran. Yeast strains that were isolated from patients with HNC were identified using conventional and molecular methods. The in vitro activities of eight common antifungal drugs against 55 isolates were investigated according to the guidelines of the Clinical and Laboratory Standard Institute (M27-A3 and M27-S4) broth microdilution document.

Results:

Among 59 patients receiving RT, the prevalence of OPC was 21 (35.59%) and 15 (25.42%) patients were diagnosed with colonization. The mean age of the patients was 55.32±13.3 years (within the range of 27-87 years). In this study, the pseudomembranous form was reported as the most clinical type of OPC. Candida albicans with the frequency of 60% was the most common type of Candida spp. that was observed in this study, although non-albicansCandida spp., such as C. glabrata (27.27%), C. tropicalis (5.45%), C. parapsilosis (3.63%), C. krusei (1.83%), and C. kefyr (1.83%) were also isolated. Considering the low minimum inhibitory concentration range of amphotericin B, compared to fluconazole, administration of this agent is a more suitable antifungal drug for extensive oral candidiasis in these patients. Among azoles, clotrimazole had low efficacy and several studied isolates (65.5%) showed resistance.

Conclusion:

Correct diagnosis as well as determining drug sensitivity and risk factors are the effective steps in reducing the complications related to oral candidiasis in people undergoing RT.

Rapidly expanded partially HLA DRB1-matched fungus-specific T cells mediate in vitro and in vivo antifungal activity

Invasive fungal infections are a major cause of disease and death in immunocompromised hosts, including patients undergoing allogeneic hematopoietic stem cell transplant (HSCT). Recovery of adaptive immunity after HSCT correlates strongly with recovery from fungal infection. Using initial selection of lymphocytes expressing the activation marker CD137 after fungal stimulation, we rapidly expanded a population of mainly CD4+ T cells with potent antifungal characteristics, including production of tumor necrosis factor α, interferon γ, interleukin-17, and granulocyte-macrophage colony stimulating factor. Cells were manufactured using a fully good manufacturing practice-compliant process. In vitro, the T cells responded to fungal antigens presented on fully and partially HLA-DRB1 antigen-matched presenting cells, including when the single common DRB1 antigen was allelically mismatched. Administration of antifungal T cells lead to reduction in the severity of pulmonary and cerebral infection in an experimental mouse model of Aspergillus. These data support the establishment of a bank of cryopreserved fungus-specific T cells using normal donors with common HLA DRB1 molecules and testing of partially HLA-matched third-party donor fungus-specific T cells as a potential therapeutic in patients with invasive fungal infection after HSCT.

Uncharted territories in the discovery of antifungal and antivirulence natural products from bacteria

Many fungi can cause deadly diseases in humans, and nearly every human will suffer from some kind of fungal infection in their lives. Only few antifungals are available, and some of these fail to treat intrinsically resistant species and the ever-increasing number of fungal strains that have acquired resistance. In nature, bacteria and fungi display versatile interactions that range from friendly co-existence to predation. The first antifungal drugs, nystatin and amphotericin B, were discovered in bacteria as mediators of such interactions, and bacteria continue to be an important source of antifungals. To learn more about the ecological bacterial-fungal interactions that drive the evolution of natural products and exploit them, we need to identify environments where such interactions are pronounced, and diverse. Here, we systematically analyze historic and recent developments in this field to identify potentially under-investigated niches and resources. We also discuss alternative strategies to treat fungal infections by utilizing the antagonistic potential of bacteria to target fungal stress pathways and virulence factors, and thereby suppress the evolution of antifungal resistance.

DNA microsatellite genotyping of potentially pathogenic Candida albicans and C. dubliniensis isolated from the oral cavity and dental prostheses

This study investigated the incidence, genetic diversity, antifungal sensitivity, and virulence of Candida albicans and C. dubliniensis isolated from subjects using dental prostheses and subjects clinically indicated for the first prosthetic rehabilitation. Subjects were divided into four groups and samples were collected twice: at first rehabilitation by removable partial (A) and total (C) dental prostheses, and replacement of the removable partial (B) and total (D) prostheses. Yeasts were genotyped using DNA microsatellite markers. Microbiological methods were used to screen for azole antifungal resistance and exoenzyme production. In the initial sampling, oral colonization by Candida was observed in 31 (53.4%) subjects in groups A (33.3%), B (68.2%), and D (65%); 20 (47.6%) subjects displayed colonization of prostheses: groups B (50%) and D (45%). The second sampling (±30 days) revealed Candida in 2 (3.4%: oral cavity) and 4 (6.9%: prosthetic) subjects from group B. C. albicans and C. dubliniensis displayed both polyclonal and monoclonal patterns of infection. Azole-resistant C. albicans and SAPs⁺ strains were prevalent. Related strains were found in one or several oral sites (mucosa and prosthesis), as well as intra- and inter-subject, -gender, -group, and -time of sampling. However, the patterns of clonality can be altered under dental care.

Upregulation of secreted aspartyl proteinase genes of fluconazole-sensitive Candida albicans isolates

Candida albicans infection development depends on several factors associated with this etiological agent, including secreted aspartyl protease (Sap) production. Sap expression commonly occurs under selective pressure caused by the presence of antifungals. Fluconazole is the main antifungal drug used for treatment or prophylaxis. This study investigated the influence of inhibitory and sub-inhibitory fluconazole concentrations on Sap activity and their gene transcription for three clinical C. albicans isolates. Two isolates presented significant increases in Sap activity and transcription of SAP 1-8 genes in the presence of 1 MIC₈₀ of fluconazole compared to the absence of the antifungal agent. The results suggest that the increase in Sap activity occurs due to an upregulation of the SAP gene transcription influenced by fluconazole. This suggests the importance of all SAP genes in the progression of bloodstream infections compared to primary tissue infection. However, this phenomenon does not occur everywhere, and it is multifactorial. This may be related to the selective pressure effect on transcription modulators. Although preliminary, these results open a new perspective for the study of virulence factors.

Early versus late onset bloodstream infection during neutropenia after high-dose chemotherapy for hematologic malignancy

PURPOSE

The length of neutropenia has a significant impact on the incidence of bloodstream infection (BSI) in cancer patients, but limited information is available about the pathogen distribution in late BSI.

METHODS

Between 2002 and 2014, BSI episodes in patients with neutropenia receiving chemotherapy for hematologic malignancies were prospectively identified by multicenter, active surveillance in Germany, Switzerland and Austria. The incidence of first BSI episodes, their microbiology and time to BSI onset during the first episode of neutropenia of 15,988 patients are described.

RESULTS

The incidence rate of BSI episodes was 14.7, 8.7, and 4.7 per 1000 patient-days in the first, second, and third week of neutropenia, respectively. BSI developed after a median of 5 days of neutropenia (interquartile range [IQR] 3-10 days). The medium duration of neutropenia to BSI onset was 4 days in Escherichia coli (IQR 3-7 days), Klebsiella spp. (2-8 days), and Staphylococcus aureus (3-6 days). In contrast, BSI due to Enterococcus faecium occurred after a median of 9 days (IQR 6-14 days; p < 0.001 vs. other BSI). Late onset of BSI (occurring after the first week of neutropenia) was also observed for Stenotrophomonas maltophilia (12 days, IQR 7-17 days; p < 0.001), and non-albicans Candida spp. (13 days, IQR 8-19 days; p < 0.001).

CONCLUSIONS

Over the course of neutropenia, the proportion of difficult to treat pathogens such as E. faecium, S. maltophilia, and Candida spp. increased. Among other factors, prior duration of neutropenia may help to guide empiric antimicrobial treatment in febrile neutropenia.

Treatment of candidemia in a nationwide setting: increased survival with primary echinocandin treatment

Background

In accordance with international guidelines, primary antifungal treatment (AFT) of candidemia with echinocandins has been nationally recommended in Denmark since 2009. Our nationwide cohort study describes the management of candidemia treatment focusing on the impact of prophylactic AFT on species distribution, the rate of adherence to the recommended national guidelines for AFT, and the effect of AFT on patient outcomes.

Materials and methods

Incident candidemia cases from a 2-year period, 2010-2011, were included. Information on AFT was retrospectively collected from patient charts. Vital status was obtained from the Danish Civil Registration System. HRs of mortality were reported with 95% CIs using Cox regression.

Results

A total of 841 candidemia patients was identified. Prior to candidemia diagnosis, 19.3% of patients received AFT (162/841). The risk of non-albicans candidemia increased after prior AFT (59.3% vs 45.5% among nontreated). Echinocandins as primary AFT were given for 44.2% (302/683) of patients. Primary treatment with echinocandins resulted in adequate treatment in a higher proportion of patients (97.7% vs 72.1%) and was associated with lower 0- to 14-day mortality compared with azole treatment (adj. HR 0.76, 95% CI: 0.55-1.06). Significantly lower 0- to 14-day mortality was observed for patients with Candida glabrata and Candida krusei with echinocandin treatment compared with azole treatment (adj. HR 0.50, 95% CI: 0.28-0.89), but not for patients with Candida albicans or Candida tropicalis.

Conclusion

The association shown between prior AFT and non-albicans species underlines the importance of treatment history when selecting treatment for candidemia. Compliance with national recommendations was low, but similar to previously reported international rates. Primary treatment of candidemia with echinocandins compared with azoles yielded both a higher proportion of adequately treated patients and improved mortality rates. This real-life setting supports guidelines recommendation, and further focus on compliance with these seems warranted.

Fluconazole impacts the extracellular matrix of fluconazole-susceptible and -resistant Candida albicans and Candida glabrata biofilms

Background: Fluconazole (FLZ) is a drug commonly used for the treatment of Candida infections. However, β-glucans in the extracellular matrices (ECMs) hinder FLZ penetration into Candida biofilms, while extracellular DNA (eDNA) contributes to the biofilm architecture and resistance. Methods: This study characterized biofilms of FLZ-sensitive (S) and -resistant (R) Candida albicans and Candida glabrata in the presence or absence of FLZ focusing on the ECM traits. Biofilms of C. albicans American Type Culture Collection (ATCC) 90028 (CaS), C. albicans ATCC 96901 (CaR), C. glabrata ATCC 2001 (CgS), and C. glabrata ATCC 200918 (CgR) were grown in RPMI medium with or without FLZ at 5× the minimum inhibitory concentration (37°C/48 h). Biofilms were assessed by colony-forming unit (CFU)/mL, biomass, and ECM components (alkali-soluble polysaccharides [ASP], water-soluble polysaccharides [WSP], eDNA, and proteins). Scanning electron microscopy (SEM) was also performed. Data were analyzed by parametric and nonparametric tests (α  =  0.05). Results: In biofilms, FLZ reduced the CFU/mL of all strains (p < 0.001), except for CaS (p = 0.937). However, the ASP quantity in CaS was significantly reduced by FLZ (p = 0.034), while the drug had no effect on the ASP levels in other strains (p > 0.05). Total biomasses and WSP were significantly reduced by FLZ in the ECM of all yeasts (p < 0.001), but levels of eDNA and proteins were unaffected (p > 0.05). FLZ affected the cell morphology and biofilm structure by hindering hyphae formation in CaS and CaR biofilms, by decreasing the number of cells in CgS and CgR biofilms, and by yielding sparsely spaced cell agglomerates on the substrate. Conclusion: FLZ impacts biofilms of C. albicans and C. glabrata as evident by reduced biomass. This reduced biomass coincided with lowered cell numbers and quantity of WSPs. Hyphal production by C. albicans was also reduced.

Prospects for adoptive T-cell therapy for invasive fungal disease

PURPOSE OF REVIEW

Invasive fungal disease (IFD) is a cause of morbidity and mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients. As more potent broad-spectrum antifungal agents are used in prophylaxis, drug resistance and less common fungal species have increased in frequency. Here we review current treatments available for IFD and examine the potential for adoptive T-cell treatment to enhance current therapeutic choices in IFD.

RECENT FINDINGS

There is growing evidence supporting the role of T cells as well as phagocytes in antifungal immunity. T cells recognizing specific antigens expressed on fungal morphotypes have been identified and the role of T-cell transfer has been explored in animal models. The clinical efficacy of adoptive transfer of antigen-specific T cells for prophylaxis and treatment of viral infections post-HSCT has raised interest in developing good manufacturing practice (GMP)-compliant methods for manufacturing and testing fungus-specific T cells after HSCT.

SUMMARY

As the outcomes of IFD post-HSCT are poor, reconstitution of antifungal immunity offers a way to correct the underlying deficiency that has caused the infection rather than simply pharmacologically suppress fungal growth. The clinical development of fungus specific T cells is in its early stages and clinical trials are needed in order to evaluate safety and efficacy.

What has changed in the treatment of invasive candidiasis? A look at the past 10 years and ahead

The treatment of invasive candidiasis has changed greatly in the past decade and must continue to evolve if we are to improve outcomes in this serious infection. A review of recent history may provide insights for the future. The morbidity and mortality of invasive candidiasis remain difficult to measure despite an obvious clinical burden. Current treatment guidelines now recommend echinocandins as first-line empirical treatment, with fluconazole as an acceptable alternative for selected patients, reflecting the efficacy demonstrated by echinocandins and increasing resistance observed with fluconazole. The selection of antifungal therapy now must consider not only resistance but also the shift in predominance from Candida albicans to non-albicans species, notably Candida glabrata. The recent emergence of Candida auris has been met with great interest, although the longer-term implications of this phenomenon remain unclear. The broad goal of treatment continues to be administration of safe, efficacious antifungal therapy as soon as possible. Diagnostic methods beyond traditional blood culture present an opportunity to shorten the time to an accurate diagnosis, and earlier treatment initiation based on prophylactic and empirical or pre-emptive strategies seeks to ensure timely therapeutic intervention. In addition, there are novel agents in the antifungal pipeline. These developments, as well as ongoing studies of dosing, toxicity and resistance development, are important items on the current research agenda and may play a role in future changes to the treatment of invasive candidiasis.

Common oral complications of head and neck cancer radiation therapy: mucositis, infections, saliva change, fibrosis, sensory dysfunctions, dental caries, periodontal disease, and osteoradionecrosis

Patients undergoing radiation therapy for the head and neck are susceptible to a significant and often abrupt deterioration in their oral health. The oral morbidities of radiation therapy include but are not limited to an increased susceptibility to dental caries and periodontal disease. They also include profound and often permanent functional and sensory changes involving the oral soft tissue. These changes range from oral mucositis experienced during and soon after treatment, mucosal opportunistic infections, neurosensory disorders, and tissue fibrosis. Many of the oral soft tissue changes following radiation therapy are difficult challenges to the patients and their caregivers and require life-long strategies to alleviate their deleterious effect on basic life functions and on the quality of life. We discuss the presentation, prognosis, and management strategies of the dental structure and oral soft tissue morbidities resulting from the administration of therapeutic radiation in head and neck patient. A case for a collaborative and integrated multidisciplinary approach to the management of these patients is made, with specific recommendation to include knowledgeable and experienced oral health care professionals in the treatment team.

Breakthrough invasive fungal diseases during voriconazole treatment for aspergillosis: A 5-year retrospective cohort study

Breakthrough invasive fungal diseases (bIFDs) during voriconazole treatment are concerning, as they are associated with high rates of mortality and pathogen distribution. To evaluate the prevalence, incidence, patient characteristics, including IFD events, and overall mortality of bIFDs during voriconazole treatment for invasive aspergillosis (IA). We retrospectively analyzed the medical records of consecutive patients who had undergone voriconazole treatment for IA and who had bIFD events between January 2011 and December 2015. Eleven bIFD events occurred in 9 patients. The prevalence and incidence of bIFDs were 2.25% (9/368) and 0.22 cases per year, respectively. Overall mortality was 44.4% (4/9). The severity of the illness and persistence of immunodeficiency, mixed infection, and low concentration of the treatment drug at the site of infection were identified as possible causes of bIFDs. Seven of 11 events (63.6%) required continued voriconazole treatment with drug level monitoring. In 4 (36.3%) cases, the treatment was changed to liposomal amphotericin B. Two cases resulted in surgical resection (18.2%). Clinicians should be aware that bIFDs during voriconazole treatment for IA can occur, and active therapeutic approaches are required in these cases.

Echinocandin Resistance in Candida Species Isolates from Liver Transplant Recipients

Liver transplant recipients are at risk of invasive fungal infections, especially candidiasis. Echinocandin is recommended as prophylactic treatment but is increasingly associated with resistance. Our aim was to assess echinocandin drug resistance in Candida spp. isolated from liver transplant recipients treated with this antifungal class. For this, all liver-transplanted patients in a University Hospital (Créteil, France) between January and June of 2013 and 2015 were included. Susceptibilities of Candida isolates to echinocandins were tested by Etest and the EUCAST reference method. Isolates were analyzed by FKS sequencing and genotyped based on microsatellites or multilocus sequence typing (MLST) profiles. Ninety-four patients were included, and 39 patients were colonized or infected and treated with echinocandin. Echinocandin resistance appeared in 3 (8%) of the treated patients within 1 month of treatment. One patient was colonized by resistant Candida glabrata, one by resistant Candida dubliniensis, and one by resistant Candida albicans. Molecular analysis found three mutations in FKS2 HS1 (F659S, S663A, and D666E) for C. glabrata and one mutation in FKS1 HS1 (S645P) for C. dubliniensis and C. albicans. Susceptible and resistant isolates belonged to the same genotype. To our knowledge, this is the first study on echinocandin resistance in Candida spp. in a liver transplant population. Most resistant isolates were found around/in digestive sites, perhaps due to lower diffusion of echinocandin in these sites. This work documents the risk of emergence of resistance to echinocandin, even after short-term treatment.

Posttreatment Antifungal Resistance among Colonizing Candida Isolates in Candidemia Patients: Results from a Systematic Multicenter Study

The prevalence of intrinsic and acquired resistance among colonizing Candida isolates from patients after candidemia was investigated systematically in a 1-year nationwide study. Patients were treated at the discretion of the treating physician. Oral swabs were obtained after treatment. Species distributions and MIC data were investigated for blood and posttreatment oral isolates from patients exposed to either azoles or echinocandins for <7 or ≥ 7 days. Species identification was confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and internal transcribed spacer (ITS) sequencing, susceptibility was examined by EUCAST EDef 7.2 methodology, echinocandin resistance was examined by FKS sequencing, and genetic relatedness was examined by multilocus sequence typing (MLST). One hundred ninety-three episodes provided 205 blood and 220 oral isolates. MLST analysis demonstrated a genetic relationship for 90% of all paired blood and oral isolates. Patients exposed to azoles for ≥ 7 days (n = 93) had a significantly larger proportion of species intrinsically less susceptible to azoles (particularly Candida glabrata) among oral isolates than among initial blood isolates (36.6% versus 12.9%; P < 0.001). A similar shift toward species less susceptible to echinocandins among 85 patients exposed to echinocandins for ≥ 7 days was not observed (4.8% of oral isolates versus 3.2% of blood isolates; P > 0.5). Acquired resistance in Candida albicans was rare (<5%). However, acquired resistance to fluconazole (29.4%; P < 0.05) and anidulafungin (21.6%; P < 0.05) was common in C. glabrata isolates from patients exposed to either azoles or echinocandins. Our findings suggest that the colonizing mucosal microbiota may be an unrecognized reservoir of resistant Candida species, especially C. glabrata, following treatment for candidemia. The resistance rates were high, raising concern in general for patients exposed to antifungal drugs.

Management of oropharyngeal mycosis in head and neck cancer occurring during (chemo) radiotherapy: an Italian radio-oncologist survey

AIMS AND BACKGROUND

Oropharyngeal candidiasis is a common disorder in head and neck cancer patients (HNCPs) who underwent (chemo)-radiotherapy. An Italian survey was conducted in order to investigate radiation oncologists' behavior in regard to diagnosis, prevention, and treatment of oral candidiasis.

METHODS AND STUDY DESIGN

Between April and May 2013, a national online 18-question survey was sent to major Italian radiotherapy centers.

RESULTS

All Italian regions were represented and 86 radiation oncologists were involved. Eighty-three percent of responders estimated that oropharyngeal candidiasis occurred in 30%-40% of their HNCPs. The majority of responders were able to recognize oral mycosis when it occurred in a localized pseudomembranous form and all responders agreed with the fact that oral candidiasis was always associated with mucositis. A prophylactic therapy was prescribed occasionally by 35% and routinely by 20% of responders. Forty percent prescribed an antifungal drug in the case of suspected mycotic infection and 20% waited for symptomatic clinical evidence before prescribing a therapy. In the presence of candidiasis, mainly topical fluconazole (59%) and itraconazole (36%) were prescribed. Concomitant chemo-radiotherapy was first identified as a risk factor for mycosis occurrence and development. Ninety-nine percent of responders believed that oral mycosis was associated with increased toxicity and 44% of them interrupted treatment due to candidiasis.

CONCLUSIONS

A variety of approaches to oropharyngeal candidiasis emerges from this survey; further clinical trials are necessary to identify the best approach for oral mycosis prevention and treatment and to establish specific international guidelines for HNCPs.

Candida colonization as a risk marker for invasive candidiasis in mixed medical-surgical intensive care units: development and evaluation of a simple, standard protocol

Colonization with Candida species is an independent risk factor for invasive candidiasis (IC), but the minimum and most practicable parameters for prediction of IC have not been optimized. We evaluated Candida colonization in a prospective cohort of 6,015 nonneutropenic, critically ill patients. Throat, perineum, and urine were sampled 72 h post-intensive care unit (ICU) admission and twice weekly until discharge or death. Specimens were cultured onto chromogenic agar, and a subset underwent molecular characterization. Sixty-three (86%) patients who developed IC were colonized prior to infection; 61 (97%) tested positive within the first two time points. The median time from colonization to IC was 7 days (range, 0 to 35). Colonization at any site was predictive of IC, with the risk of infection highest for urine colonization (relative risk [RR]=2.25) but with the sensitivity highest (98%) for throat and/or perineum colonization. Colonization of ≥2 sites and heavy colonization of ≥1 site were significant independent risk factors for IC (RR=2.25 and RR=3.7, respectively), increasing specificity to 71% to 74% but decreasing sensitivity to 48% to 58%. Molecular testing would have prompted a resistance-driven decision to switch from fluconazole treatment in only 11% of patients infected with C. glabrata, based upon species-level identification alone. Positive predictive values (PPVs) were low (2% to 4%) and negative predictive values (NPVs) high (99% to 100%) regardless of which parameters were applied. In the Australian ICU setting, culture of throat and perineum within the first two time points after ICU admission captures 84% (61/73 patients) of subsequent IC cases. These optimized parameters, in combination with clinical risk factors, should strengthen development of a setting-specific risk-predictive model for IC.

Epidemiology and outcome of candidaemia in patients with oncological and haematological malignancies: results from a population-based surveillance in Spain

A prospective, population-based surveillance on candidaemia was implemented in five metropolitan areas of Spain from May 2010 to April 2011. We aimed to describe the distribution and susceptibility pattern of Candida species, and to evaluate risk factors for mortality in patients with oncological (solid tumours) and haematological malignancies. Adults (≥ 16 years) with cancer were included in the present report. Impact of therapeutic strategies on 7- and 30-day mortality were analysed by logistic regression, adjusting for propensity score by inverse weighting probability of receiving early antifungal treatment and catheter removal. We included 238 (32.6%) patients (195 oncological, 43 haematological). Compared with oncological patients, haematological patients were more likely to have received chemotherapy (53.5% versus 17.4%, p < 0.001) or corticosteroids (41.9% versus 21%, p < 0.001), and have neutropenia (44.2% versus 1.5%, p < 0.001). Overall, 14.8% of patients developed breakthrough candidaemia. Non-albicans Candida species (71.1% versus 55.6%, p 0.056) and Candida tropicalis (22.2% versus 7.6%, p 0.011) were more frequent in haematological patients. Based on EUCAST breakpoints, 27.6% of Candida isolates were non-susceptible to fluconazole. Resistance to echinocandins was negligible. Mortality at 7 and 30 days was 12.2% and 31.5%, respectively, and did not differ significantly between the patient groups. Prompt antifungal therapy together with catheter removal (≤ 48 hours) was associated with lower mortality at 7 days (adjusted OR 0.05; 95% CI 0.01-0.42) and 30 days (adjusted OR 0.27; 95% CI 0.16-0.46). In conclusion, non-albicans species are emerging as the predominant isolates, particularly in haematological patients. Prompt, adequate antifungal treatment plus catheter removal may lead to a reduction in mortality.

Pharmacokinetics and pharmacodynamics of antifungals in children and their clinical implications

Invasive fungal infections are a significant cause of morbidity and mortality in children. Successful management of these systemic infections requires identification of the causative pathogen, appropriate antifungal selection, and optimisation of its pharmacokinetic and pharmacodynamic properties to maximise its antifungal activity and minimise toxicity and the emergence of resistance. This review highlights salient scientific advancements in paediatric antifungal pharmacotherapies and focuses on pharmacokinetic and pharmacodynamic studies that underpin current clinical decision making. Four classes of drugs are widely used in the treatment of invasive fungal infections in children, including the polyenes, triazoles, pyrimidine analogues and echinocandins. Several lipidic formulations of the polyene amphotericin B have substantially reduced the toxicity associated with the traditional amphotericin B formulation. Monotherapy with the pyrimidine analogue flucytosine rapidly promotes the emergence of resistance and cannot be recommended. However, when used in combination with other antifungal agents, therapeutic drug monitoring of flucytosine has been shown to reduce high peak flucytosine concentrations, which are strongly associated with toxicity. The triazoles feature large inter-individual pharmacokinetic variability, although this pattern is less pronounced with fluconazole. In clinical trials, posaconazole was associated with fewer adverse effects than other members of the triazole family, though both posaconazole and itraconazole display erratic absorption that is influenced by gastric pH and the gastric emptying rate. Limited data suggest that the clinical response to therapy may be improved with higher plasma posaconazole and itraconazole concentrations. For voriconazole, pharmacokinetic studies among children have revealed that children require twice the recommended adult dose to achieve comparable blood concentrations. Voriconazole clearance is also affected by the cytochrome P450 (CYP) 2C19 genotype and hepatic impairment. Therapeutic drug monitoring is recommended as voriconazole pharmacokinetics are highly variable and small dose increases can result in marked changes in plasma concentrations. For the echinocandins, the primary source of pharmacokinetic variability stems from an age-dependent decrease in clearance with increasing age. Consequently, young children require larger doses per kilogram of body weight than older children and adults. Routine therapeutic drug monitoring for the echinocandins is not recommended. The effectiveness of many systemic antifungal agents has been correlated with pharmacodynamic targets in in vitro and in murine models of invasive candidiasis and aspergillosis. Further study is needed to translate these findings into optimal dosing regimens for children and to understand how these agents interact when multiple antifungal agents are used in combination.

One small step for a yeast--microevolution within macrophages renders Candida glabrata hypervirulent due to a single point mutation

Candida glabrata is one of the most common causes of candidemia, a life-threatening, systemic fungal infection, and is surpassed in frequency only by Candida albicans. Major factors contributing to the success of this opportunistic pathogen include its ability to readily acquire resistance to antifungals and to colonize and adapt to many different niches in the human body. Here we addressed the flexibility and adaptability of C. glabrata during interaction with macrophages with a serial passage approach. Continuous co-incubation of C. glabrata with a murine macrophage cell line for over six months resulted in a striking alteration in fungal morphology: The growth form changed from typical spherical yeasts to pseudohyphae-like structures – a phenotype which was stable over several generations without any selective pressure. Transmission electron microscopy and FACS analyses showed that the filamentous-like morphology was accompanied by changes in cell wall architecture. This altered growth form permitted faster escape from macrophages and increased damage of macrophages. In addition, the evolved strain (Evo) showed transiently increased virulence in a systemic mouse infection model, which correlated with increased organ-specific fungal burden and inflammatory response (TNFα and IL-6) in the brain. Similarly, the Evo mutant significantly increased TNFα production in the brain on day 2, which is mirrored in macrophages confronted with the Evo mutant, but not with the parental wild type. Whole genome sequencing of the Evo strain, genetic analyses, targeted gene disruption and a reverse microevolution experiment revealed a single nucleotide exchange in the chitin synthase-encoding CHS2 gene as the sole basis for this phenotypic alteration. A targeted CHS2 mutant with the same SNP showed similar phenotypes as the Evo strain under all experimental conditions tested. These results indicate that microevolutionary processes in host-simulative conditions can elicit adaptations of C. glabrata to distinct host niches and even lead to hypervirulent strains.

Evolution is not limited to making new species emerge and others perish over the millennia. It is also a central force in shorter-term interactions between microbes and hosts. A good example can be found in fungi, which are an underestimated cause of human diseases. Some fungi exist as commensals, and have adapted well to life on human epithelia. But as facultative pathogens, they face a different, hostile environment. We tested the ability of C. glabrata, a pathogen closely related to baker's yeast, to adapt to macrophages. We found that by adaptation, it changed its growth type completely. This allowed the fungus to escape the phagocytes, and increased its virulence in a mouse model. Sequencing the complete genome revealed surprisingly few mutations. Further analyses allowed us to detect the single mutation responsible for the phenotype, and to recreate it in the parental strain. Our work shows that fungi can adapt to immune cells, and that this adaptation can lead to an increased virulence. Since commensals are continuously exposed to host cells, we suggest that this ability could lead to unexpected phenotype changes, including an increase in virulence potential.

Primary antifungal prophylaxis with micafungin in patients with haematological malignancies: real-life data from a retrospective single-centre observational study

Mould-active antifungal prophylaxis is increasingly used in patients at risk for invasive fungal disease. Between June 2011 and June 2012, one hundred patients with various haematological malignancies at risk for invasive fungal disease received primary antifungal prophylaxis with intravenous micafungin at a daily dosage of 50 mg during neutropenia. The median number of days on micafungin prophylaxis was 14 (range, 6-48 d). The incidence of proven and probable breakthrough invasive fungal diseases (bIFDs) was 6% and 3%, respectively. There were two bloodstream infections caused by yeasts or yeast-like fungi (Candida krusei, Trichosporon asahii) in two patients during the neutropenic phase after allogeneic haematopoietic stem cell transplantation. Four proven bIFDs caused by non-Aspergillus moulds and three cases of probable pulmonary bIFDs were documented during the neutropenic phase after induction/consolidation chemotherapy for acute leukaemia. Colonisation with Candida spp. was documented in 51% of the patients with none of the isolates being in vitro micafungin resistant. Compared to a historical control, receiving primary prophylaxis with posaconazole micafungin is at least as effective in preventing IFD. In both cohorts, bIFDs were exclusively caused by emerging pathogens with a highly preserved in vitro sensitivity to amphotericin B.

Prevention and treatment of oral mucositis in patients with head and neck cancer treated with (chemo) radiation: report of an Italian survey

PURPOSE

There is a limited number of therapies with a high level of recommendations for mucositis, while several strategies are currently employed with a limited evidence for efficacy. A national survey among Italian oncologists who treat head and neck cancer (HNC) was conducted in order to assess the most common preventive and therapeutic protocols (including nutritional support and pain control) for oral mucositis (OM) in patients undergoing chemoradiotherapy.

METHODS

From September to November 2012, a nationwide electronic survey with 21 focused items was proposed to chemotherapy and radiotherapy centers.

RESULTS

We collected 111 answers. Common Terminology Criteria for Adverse Events (CTCAE) scale is employed by 55% of the physicians in assessing mucosal toxicity. The most relevant predictive factors for OM development are considered smoke, alcohol use, planned radiotherapy, and concurrent use of radiosensitizing chemotherapy. Prophylactic gastrostomy is adopted in <10% of the patients. Preventive antibiotics or antimycotics are prescribed by 46% of the responders (mainly local or systemic antimycotic drugs). Alkalinizing mouthwashes or coating agents are frequently adopted (70% of the cases). Among therapeutic interventions, systemic fluconazole is administered by 80% of the physicians. Pain is mainly treated by weak followed by strong opioids.

CONCLUSIONS

A variety of preventive and therapeutic protocols for OM exists among the participating Italian centers, with some uniformity in respect to nutritional support, use of antimycotic and painkillers. There is an urgent need for well-conducted clinical trials aimed at assessing the best choices for OM prevention and treatment in HNC.

Comparison of itraconazole, voriconazole, and posaconazole as oral antifungal prophylaxis in pediatric patients following allogeneic hematopoietic stem cell transplantation

Oral antifungal prophylaxis with extended-spectra azoles is widely used in pediatric patients after allogeneic hematopoietic stem cell transplantation (HSCT), while controlled studies for oral antifungal prophylaxis after bone marrow transplantation in children are not available. This survey analyzed patients who had received either itraconazole, voriconazole, or posaconazole. We focused on the safety, feasibility, and initial data of efficacy in a cohort of pediatric patients and adolescents after high-dose chemotherapy and HSCT. Fifty consecutive pediatric patients received itraconazole, 50 received voriconazole, and 50 pediatric patients received posaconazole after HSCT as oral antifungal prophylaxis. The observation period lasted from the start of oral prophylactic treatment with itraconazole, voriconazole, or posaconazole until two weeks after terminating the oral antifungal prophylaxis. No incidences of proven or probable invasive mycosis were observed during itraconazole, voriconazole, or posaconazole treatment. A total of five possible invasive fungal infections occurred, two in the itraconazole group (4 %) and three in the voriconazole group (6 %). The percentage of patients with adverse events potentially related to clinical drugs were 14 % in the voriconazole group, 12 % in the itraconazole group, and 8 % in the posaconazole group. Itraconazole, voriconazole, and posaconazole showed comparable efficacy as antifungal prophylaxis in pediatric patients after allogeneic HSCT.

Molecular fingerprints to identify Candida species

A wide range of molecular techniques have been developed for genotyping Candida species. Among them, multilocus sequence typing (MLST) and microsatellite length polymorphisms (MLP) analysis have recently emerged. MLST relies on DNA sequences of internal regions of various independent housekeeping genes, while MLP identifies microsatellite instability. Both methods generate unambiguous and highly reproducible data. Here, we review the results achieved by using these two techniques and also provide a brief overview of a new method based on high-resolution DNA melting (HRM). This method identifies sequence differences by subtle deviations in sample melting profiles in the presence of saturating fluorescent DNA binding dyes.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: non-neutropenic adult patients

This part of the EFISG guidelines focuses on non-neutropenic adult patients. Only a few of the numerous recommendations can be summarized in the abstract. Prophylactic usage of fluconazole is supported in patients with recent abdominal surgery and recurrent gastrointestinal perforations or anastomotic leakages. Candida isolation from respiratory secretions alone should never prompt treatment. For the targeted initial treatment of candidaemia, echinocandins are strongly recommended while liposomal amphotericin B and voriconazole are supported with moderate, and fluconazole with marginal strength. Treatment duration for candidaemia should be a minimum of 14 days after the end of candidaemia, which can be determined by one blood culture per day until negativity. Switching to oral treatment after 10 days of intravenous therapy has been safe in stable patients with susceptible Candida species. In candidaemia, removal of indwelling catheters is strongly recommended. If catheters cannot be removed, lipid-based amphotericin B or echinocandins should be preferred over azoles. Transoesophageal echocardiography and fundoscopy should be performed to detect organ involvement. Native valve endocarditis requires surgery within a week, while in prosthetic valve endocarditis, earlier surgery may be beneficial. The antifungal regimen of choice is liposomal amphotericin B +/- flucytosine. In ocular candidiasis, liposomal amphotericin B +/- flucytosine is recommended when the susceptibility of the isolate is unknown, and in susceptible isolates, fluconazole and voriconazole are alternatives. Amphotericin B deoxycholate is not recommended for any indication due to severe side effects.

Candida parapsilosis and the neonate: epidemiology, virulence and host defense in a unique patient setting

Invasive candidiasis is a common problem in premature infants that leads to high morbidity and mortality. Although Candida albicans has historically been the most prominent species involved in these infections and has therefore been the subject of the most study, Candida parapsilosis is increasing in frequency, and neonates are disproportionately affected. This article reviews unique aspects of the epidemiology of this organism as well as strategies for prophylaxis against invasive candidiasis in general. Additionally, important differences between C. parapsilosis and C. albicans are coming to light related to virulence determinants and interactions with components of host immunity. These developments are reviewed while highlighting the significant gaps in our understanding that remain to be elucidated.

Newer antifungal agents

PURPOSE OF REVIEW

In recent years there has been an evolution of a better understanding of the pharmacology and clinical indications of existing antifungal agents and also the development of new broad-spectrum triazoles and a newer class of antifungal agents, the echinocandins. The availability of these agents has broadened the therapeutic options of invasive fungal disease among children and consequently antifungal therapy has become increasingly complex.

RECENT FINDINGS

Adoption of adult guidelines' recommendations has been used to guide pediatric treatment as specific pediatric data were often lacking. This approach has not always selected the most appropriate therapy for newborns or young infants, as the under-dosage of voriconazole based on adult data revealed. Therefore, a detailed understanding of the available antifungal agents in children is crucial for the successful treatment of these serious infections.

SUMMARY

In this review we summarize the main findings regarding antifungal treatment among children that have been recently published, focusing on the pharmacology and pediatric use of newer antifungal agents.

Oral infections caused by yeasts in patients with head and neck cancer undergoing radiotherapy. Identification of the yeasts and evaluation of their antifungal susceptibility

Yeasts occur as part of the normal human microbiota. Nevertheless, some species are opportunistic, affecting immunocompromised patients such as those undergoing oncologic treatment.

OBJECTIVE

To detect the presence of yeasts in patients suffering from head and neck cancer who are receiving radiation therapy and display lesions in the oral cavity, compatible with candidiasis; and to evaluate the antifungal susceptibility of the isolates recovered.

METHODS

Sixty samples from patients were obtained by swabbing the oral mucosa. Identification of isolates were performed by classical taxonomic, morphological and biochemical methods as well as by using commercial identification kits. Susceptibility to antifungal drugs was determined by the agar diffusion method with Neosensitabs(®) disks.

RESULTS

Forty-six samples (77%) yielded positive findings, and species recovered were: Candida albicans (22 isolates), Candida tropicalis (13 isolates), Candida parapsilosis (six strains), Candida krusei (three strains), Candida dubliniensis and Saccharomyces cerevisiae (one each). All strains were susceptible to itraconazole, clotrimazole, voriconazole, nystatin and amphotericin B. On the other hand, 65% of strains were miconazole-susceptible while 35%, showed intermediate susceptibility. With regard to ketoconazole, only three strains (7%) corresponding to C. albicans (one isolate) and C. krusei (two isolates) displayed intermediate susceptibility. Only C. krusei strains were resistant to fluconazole while all the other species were susceptible. Eventually, only six isolates (13%) were susceptible to terbinafine while the remaining strains were resistant in vitro.

CONCLUSION

Early detection of etiological agents causing lesions, as well as the evaluation of their susceptibility to commonly used drugs, are crucial in order to choose the appropriate treatment that will minimize complications while improving the quality of patients' lives.

Posaconazole for the Treatment of Oropharyngeal Candidiasis, Including Triazole-Resistant Disease, in HIV-positive patients

Oropharyngeal candidiasis is a common affliction in HIV-positive patients worldwide. Although the incidence has decreased with the advent of potent antiviral combinations, it continues to be a cause of significant morbidity. Historically, fluconazole or itraconazole was the treatment of choice for oropharyngeal candidiasis, but increasing incidence of resistance and high recurrence rates mandate the use of alternative therapies. Posaconazole, a broad-spectrum second-generation triazole antifungal agent, has been studied in both first-line and salvage settings for treatment of oropharyngeal candidiasis. Posaconazole is well-tolerated, yields high response rates and demonstrates durable response rates with long-term use. This review will provide state-of-the-art knowledge of pharmacology and therapeutics of posaconazole focusing on the indication for oropharyngeal candidiasis in HIV-positive patients.

Epidemiology and prevalence of oropharyngeal candidiasis in Spanish patients with head and neck tumors undergoing radiotherapy treatment alone or in combination with chemotherapy

OBJECTIVE

To describe the oropharyngeal candidiasis (OPC) prevalence in Spanish patients with head and neck cancer undergoing radiotherapy, alone or combined with chemotherapy. Secondary objectives were to determine the prevalence of Candida species colonization, and to explore whether different Candida species colonizing the oral cavity and the treatment were associated with a higher prevalence of OPC.

METHODS

This is an observational, cross-sectional, multicentre study, conducted in Spanish radiation oncology units. Patients were diagnosed with head and neck cancer and started a radiotherapy treatment alone or combined with chemotherapy at the moment of their inclusion (N = 92).

RESULTS

The OPC prevalence was 26 %. The identification of colonizing pathogens was performed in 49 patients, and Candida albicans was the dominant yeast (69 %), while non-albicans Candida was only found in 15 patients (31 %). Patients with C. albicans colonization had a significant higher prevalence of OPC compared to patients colonized by non-albicans Candida (p = 0.0273), but no difference was found regarding the OPC prevalence in patients receiving only radiotherapy compared to patients with both radiotherapy and chemotherapy treatments.

CONCLUSIONS

Our data represent a step further in the knowledge of Candida species present in Spanish patients with head and neck tumors under radiation therapy. This is an essential step to manage the prophylaxis and treatment of OPC, since it might lead to severe clinical complications causing treatment interruption and, thus, representing a reduction in anti-tumor efficacy.

The effect of biomaterials and antifungals on biofilm formation by Candida species: a review

Candida albicans, C. glabrata, C. parapsilosis, and C. tropicalis are able to form biofilms on virtually any biomaterial implanted in a human host. Biofilms are a primary cause of mortality in immunocompromised and hospitalized patients, as they cause recurrent and invasive candidiasis, which is difficult to eradicate. This is due to the fact that the biofilm cells show high resistance to antifungal treatments and the host defense mechanisms, and exhibit an excellent ability to adhere to biomaterials. Elucidation of the mechanisms of antifungal resistance in Candida biofilms is of unquestionable importance; therefore, this review analyzes both the chemical composition of biomaterials used to fabricate the medical devices, as well as the Candida genes and proteins that confer drug resistance.