Impact of new antifungal breakpoints on antifungal resistance in Candida species

Oteseconazole for the Treatment of Recurrent Vulvovaginal Candidiasis: A Drug Review

OBJECTIVE

The objective of the study is to describe and analyze the pharmacodynamics and pharmacokinetics of oteseconazole as well as the clinical evidence supporting the efficacy of oteseconazole in treating recurrent vulvovaginal candidiasis (RVVC).

DATA SOURCES

A literature search was conducted using MEDLINE and EMBASE databases (2015-June 2023). Search terms included "oteseconazole" OR "VT-1161" or "VIVJOA" AND "RVVC" or "recurrent vulvovaginal candidiasis" or "vulvovaginal candidiasis." Conference abstracts, bibliographies, clinical trials, and drug monographs were included for review.

STUDY SELECTION AND DATA EXTRACTION

Relevant studies in English and clinical trials conducted in humans were reviewed.

DATA SYNTHESIS

Oteseconazole is approved for the treatment of RVVC. In 2 identical phase III studies, oteseconazole was superior to placebo through 48 weeks for preventing recurrence of RVVC (6.7% vs 42.8%, P < 0.001 and 3.9% vs 39.4%, P < 0.001). In the only phase III trial comparing oteseconazole against active drug, oteseconazole was well tolerated and exhibited noninferiority to fluconazole in acute treatment and superiority to placebo for prevention maintenance through 50 weeks (5.1% vs 42.2%, P < 0.001).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING AGENTS

This review describes the use of oteseconazole for the treatment of RVVC as compared with fluconazole. Oteseconazole is an effective treatment option for common pathogens causing vulvovaginal candidiasis, including Candida and fluconazole-resistant Candida.

CONCLUSIONS

Oteseconazole is an effective and safe treatment option for the management of RVVC though current research lacks comparison with established maintenance regimens. Additional research is needed to ascertain the placement of oteseconazole in the treatment of RVVC.

A mechanism study on the synergistic effects of rifapentine and fluconazole against fluconazole-resistant Candida albicans in vitro

Candida albicans (C. albicans) is one of the most common clinical isolates of systemic fungal infection. Long-term and inappropriate use of antifungal drugs can cause fungal resistance, which poses a great challenge to the clinical treatment of fungal infections. The combination of antifungal drugs and non-antifungal drugs to overcome the problem of fungal resistance has become a research hotspot in recent years. Our previous study found that the combination of rifapentine (RFT) and fluconazole (FLC) has a significant synergistic against FLC-resistant C. albicans. The present study aimed to further verify the synergistic effect between FLC and RFT against the FLC-resistant C. albicans 100, and explore the underlying mechanism. The growth curve and spot assay test not only showed the synergistic effect of FLC and RFT on FLC-resistant C. albicans in vitro but exhibited a dose-dependent effect on RFT, indicating that RFT may play a principal role in the synergic effect of the two drugs. Flow cytometry showed that the combined use of RFT and FLC arrested cells in the G2/M phase, inhibiting the normal division and proliferation of FLC-resistant C. albicans. Transmission electron microscopy (TEM) demonstrated that FLC at a low concentration could still cause a certain degree of damage to the cell membrane in the FLC-resistant C. albicans, as represented by irregular morphologic changes and some defects observed in the cell membrane. When FLC was used in combination with RFT, the nuclear membrane was dissolved and the nucleus was condensed into a mass. Detection of the intracellular drug concentration of fungi revealed that the intracellular concentration of RFT was 31-195 fold that of RFT alone when it was concomitantly used with FLC. This indicated that FLC could significantly increase the concentration of RFT in cells, which may be due to the damage caused to the fungal cell membrane by FLC. In short, the present study revealed a synergistic mechanism in the combined use of RFT and FLC, which may provide a novel strategy for the clinical treatment of FLC-resistant C. albicans.

New treatment options for critically important WHO fungal priority pathogens

BACKGROUND

Yet often overlooked in public health discourse, fungal infections pose a crucial global disease burden associated with annual mortality rates approximately equal to tuberculosis and HIV. In response, the WHO published its first global priority list of fungal pathogens in 2022 assigning Aspergillus fumigatus, Candida albicans, Candida auris, and Cryptococcus neoformans to the critical group.

OBJECTIVES

This review provides succinct insights into novel antifungals in development, aiming to contribute valuable information and perspectives with a focus on recent clinical findings and new treatment approaches for critical members of the WHO fungal pathogen priority list.

SOURCES

PubMed literature search using 'Aspergillus fumigatus', 'Cryptococcus neoformans', 'Candida auris', and 'Candida albicans', along with the names of novel antifungal substances, including 'fosmanogepix', 'ibrexafungerp', 'opelconazole', 'oteseconazole', 'MAT2203', 'olorofim', and 'rezafungin' was conducted.

CONTENT

For each critical pathogen, current issues and global clinical data from recent trials are covered. The remarkable development of three new antifungal therapeutics recently receiving Food and Drug Administration approval (ibrexafungerp-June 2021, oteseconazole -April 2022, and rezafungin-March 2023) is outlined, with two more exciting new antifungal substances, namely, olorofim and fosmanogepix expecting approval within the next years. Ibrexafungerp, fosmanogepix, and rezafungin have additionally been granted orphan drug status by the European Medicines Agency in Europe (ibrexafungerp-November 2021, fosmanogepix-July 2022, and rezafungin-January 2024).

IMPLICATIONS

Although the limited number of targets and the emergence of resistance have posed challenges to antifungal treatment, new drugs such as ibrexafungerp, rezafungin, fosmanogepix, or olorofim have shown promising clinical efficacy. These drugs not only provide alternative options for invasive fungal infections but also alleviate treatment in outpatient settings. More clinical data, implementation of stewardship programmes, and surveillance, including utilization of drugs in agriculture, are necessary to prevent resistance development and to ensure the safety and efficacy of these new agents.

Nanotechnology-based Drug Delivery of Topical Antifungal Agents

Among the various prominent fungal infections, superficial ones are widespread. A large number of antifungal agents and their formulations for topical use are commercially available. They have some pharmacokinetic limitations which cannot be retracted by conventional delivery systems. While nanoformulations composed of lipidic and polymeric nanoparticles have the potential to overcome the limitations of conventional systems. The broad spectrum category of antifungals i.e. azoles (ketoconazole, voriconazole, econazole, miconazole, etc.) nanoparticles have been designed, prepared and their pharmacokinetic and pharmacodynamic profile was established. This review briefly elaborates on the types of nano-based topical drug delivery systems and portrays their advantages for researchers in the related field to benefit the available antifungal therapeutics.

Antifungal Drug Concentration Impacts the Spectrum of Adaptive Mutations in Candida albicans

Invasive fungal infections are a leading global cause of human mortality. Only three major classes of antifungal drugs are widely used, and resistance to all three classes can arise rapidly. The most widely prescribed antifungal drug, fluconazole, disseminates rapidly and reaches a wide range of concentrations throughout the body. The impact of drug concentration on the spectrum and effect of mutations acquired during adaptation is not known for any fungal pathogen, and how the specific level of a given stress influences the distribution of beneficial mutations has been poorly explored in general. We evolved 144 lineages from three genetically distinct clinical isolates of Candida albicans to four concentrations of fluconazole (0, 1, 8, and 64 μg/ml) and performed comprehensive phenotypic and genomic comparisons of ancestral and evolved populations. Adaptation to different fluconazole concentrations resulted in distinct adaptive trajectories. In general, lineages evolved to drug concentrations close to their MIC50 (the level of drug that reduces growth by 50% in the ancestor) tended to rapidly evolve an increased MIC50 and acquired distinct segmental aneuploidies and copy number variations. By contrast, lineages evolved to drug concentrations above their ancestral MIC50 tended to acquire a different suite of mutational changes and increased in drug tolerance (the ability of a subpopulation of cells to grow slowly above their MIC50). This is the first evidence that different concentrations of drug can select for different genotypic and phenotypic outcomes in vitro and may explain observed in vivo drug response variation.

Nanotechnology-Based Approaches for Voriconazole Delivery Applied to Invasive Fungal Infections

Invasive fungal infections increase mortality and morbidity rates worldwide. The treatment of these infections is still limited due to the low bioavailability and toxicity, requiring therapeutic monitoring, especially in the most severe cases. Voriconazole is an azole widely used to treat invasive aspergillosis, other hyaline molds, many dematiaceous molds, Candida spp., including those resistant to fluconazole, and for infections caused by endemic mycoses, in addition to those that occur in the central nervous system. However, despite its broad activity, using voriconazole has limitations related to its non-linear pharmacokinetics, leading to supratherapeutic doses and increased toxicity according to individual polymorphisms during its metabolism. In this sense, nanotechnology-based drug delivery systems have successfully improved the physicochemical and biological aspects of different classes of drugs, including antifungals. In this review, we highlighted recent work that has applied nanotechnology to deliver voriconazole. These systems allowed increased permeation and deposition of voriconazole in target tissues from a controlled and sustained release in different routes of administration such as ocular, pulmonary, oral, topical, and parenteral. Thus, nanotechnology application aiming to delivery voriconazole becomes a more effective and safer therapeutic alternative in the treatment of fungal infections.

Phase 3 study evaluating the safety and efficacy of oteseconazole in the treatment of recurrent vulvovaginal candidiasis and acute vulvovaginal candidiasis infections

BACKGROUND

Recurrent vulvovaginal candidiasis affects nearly 138 million women globally each year. In the United States, fluconazole is considered the standard of care for acute vulvovaginal candidiasis, but until recently there was no US Food and Drug Administration-approved drug for the treatment of recurrent vulvovaginal candidiasis. Oteseconazole is a novel oral selective inhibitor of fungal lanosterol demethylase (sterol 14α-demethylase cytochrome P450, an enzyme required for fungal growth) approved for the treatment of recurrent vulvovaginal candidiasis.

OBJECTIVE

This study was conducted to evaluate the efficacy and safety of oral oteseconazole (VT-1161) in the prevention of recurrent culture-verified acute vulvovaginal candidiasis episodes through 50 weeks in participants with recurrent vulvovaginal candidiasis and to compare the efficacy of oteseconazole and fluconazole in the treatment of the presenting acute vulvovaginal candidiasis episode.

STUDY DESIGN

Women and postmenarcheal girls aged ≥12 years with a history of recurrent vulvovaginal candidiasis (N=219) were enrolled at 38 US sites. Eligible participants presenting with an active vulvovaginal candidiasis infection entered an induction phase in which they were randomly assigned 2:1 to receive 600 mg oral oteseconazole on day 1 and 450 mg on day 2, with matching placebo capsules, or to 3 sequential 150-mg oral doses (once every 72 hours) of fluconazole, with matching placebo capsules. Following the 2-week induction phase, the 185 participants with resolved acute vulvovaginal candidiasis infection (a clinical signs and symptoms score of <3) entered the maintenance phase and received 150 mg of oteseconazole or placebo weekly for 11 weeks. Participants were observed for an additional 37 weeks.

RESULTS

In the induction phase, oteseconazole was noninferior to fluconazole in the proportion of participants in the intent-to-treat population with resolved acute vulvovaginal candidiasis infection at the week 2 (day 14) test-of-cure visit, with 93.2% of participants on oteseconazole vs 95.8% on fluconazole achieving resolution. In the maintenance phase, oteseconazole was superior to placebo in the proportion of participants in the intent-to-treat population with ≥1 culture-verified acute vulvovaginal candidiasis episode through 50 weeks, 5.1% compared with 42.2%, respectively (P<.001). Overall, treatment-emergent adverse event rates were similar in both groups: 54% for participants who received oteseconazole in the induction and maintenance phases vs 64% for participants who received fluconazole in the induction phase and placebo in the maintenance phase. Most treatment-emergent adverse events in each group were mild or moderate, with 3.4% of treatment-emergent adverse events graded as severe or higher in the OTESECONAZOLE/oteseconazole group vs 4.2% in FLUCONAZOLE/placebo group.

CONCLUSION

In participants with recurrent vulvovaginal candidiasis, oteseconazole was safe and efficacious in the treatment and prevention of recurrent acute vulvovaginal candidiasis episodes and was noninferior to vulvovaginal candidiasis standard-of-care fluconazole in the treatment of the presenting acute vulvovaginal candidiasis infection.

In Vitro, Ex Vivo, and In Vivo Evaluation of Nanoparticle-Based Topical Formulation Against Candida albicans Infection

Ketoconazole is commonly used in the treatment of topical fungal infections. The therapy requires frequent application for several weeks. Systemic side effects, allergic reactions, and prolonged treatment are often associated with non-compliance and therapy failure. Hence, we developed an optimized topical antifungal gel that can prolong the release of drug, reduce systemic absorption, enhance its therapeutic effect, and improve patient compliance. Ketoconazole-loaded PLGA nanoparticles were prepared by the emulsion/solvent evaporation method and were characterized with respect to colloidal properties, surface morphology, and drug entrapment efficiency. The optimized ketoconazole-loaded PLGA nanoparticles and commercially available silver nanoparticles were incorporated into a Carbopol 934P-NF gel base. This arrangement was characterized and compared with commercially available 2% ketoconazole cream to assess physical characteristics of the gel, in vitro drug release, ex vivo skin permeation and retention, and in vivo studies on Wister male albino rats. The results showed that polymeric PLGA nanoparticles were very effective in extending the release of ketoconazole in our optimized formulation. Nanoparticles were smooth, spherical in shape, and below 200 nm in size which is consistent with the data obtained from light scattering and SEM images. The ex vivo data showed that our gel formulation could strongly reduce drug permeation through the skin, and more than 60% of the drug was retained on the upper surface of the skin in contrast to 38.42% of the commercial cream. The in vivo studies showed that gel formulation could effectively treat the infection. This study demonstrates that our topical gel could be effective in sustaining the release of drug and suggests its potential use as a possible strategy to combat antifungal-resistant Candida albicans.

Poly(DL-lactic acid) scaffolds as a bone targeting platform for the co-delivery of antimicrobial agents against S. aureus-C. albicans mixed biofilms

New strategies for the treatment of polymicrobial bone infections are required. In this study, the co-delivery of two antimicrobials by poly(D,L-lactic acid) (PDLLA) scaffolds was investigated in a polymicrobial biofilm model. PDLLA scaffolds were prepared by solvent casting/particulate leaching methodology, incorporating minocycline and voriconazole as clinically relevant antimicrobial agents. The scaffolds presented a sponge-like appearance, suitable to support cell proliferation and drug release. Single- and dual-species biofilm models of Staphylococcus aureus and Candida albicans were developed and characterized. S. aureus presented a higher ability to form single-species biofilms, compared to C. albicans. Minocycline and voriconazole-loaded PDLLA scaffolds showed activity against S. aureus and C. albicans single- and dual-biofilms. Ultimately, the cytocompatibility/functional activity of PDLLA scaffolds observed in human MG-63 osteosarcoma cells unveil their potential as a next-generation co-delivery system for antimicrobial therapy in bone infections.

Efficacy of intravitreal povidone-iodine administration for the treatment of Candida albicans endophthalmitis in rabbits

This study aimed to investigate the efficacy of intravitreal povidone-iodine (PI) administration for the treatment of Candida albicans endophthalmitis. Forty New Zealand white rabbits were divided into four groups (n = 10 per group). After the induction of endophthalmitis using Candida albicans, groups A, B, and C received single intravitreal injections of 0.035 mg voriconazole, 0.3 mg PI, and their combination, respectively. Rabbits that were administered sham injections were in group D as controls. Fundus photography, vitreous culture, electroretinography (ERG), and histologic examinations of the retina were conducted on day 7. The anterior chamber flare (grade 0 to 4), severity of iritis (grade 0 to 4), and vitreous opacity (grade 0 to 3) were scored. Candida albicans was cultured in the vitreous sample. On day 7, the vitreous opacities were found in all groups. Compared to that in group D, groups A, B, and C showed a lower score for flare (p < 0.001) and iritis (p < 0.001) and less fungal growth in the vitreous culture (n = 2, 1, 1, and 10 in groups A, B, C, and D, respectively; p < 0.001). Furthermore, ERG and histologic findings demonstrated less affected a- and b-waves and damaged retinal tissues in groups A, B, and C. However, these findings were not different among groups A, B, and C. PI significantly improved Candida albicans endophthalmitis, and the effect was comparable that of the voriconazole, although some vitreous opacities remained. No synergistic effect of the combination of PI and voriconazole was observed. Intravitreal PI may be useful to treat Candida albicans endophthalmitis.

Emerging of Fatal Colitis with Multidrug-Resistant Candida glabrata after Small Bowel Transplantation

Background

Small bowel transplantation is a potential option for patients with intestinal-failure, and the incidences of infections caused by Candida species that are more resistant to antifungal drugs are increasing in these patients. In this manuscript, we reported a case of fatal colitis after small bowel transplantation induces by multidrug-resistant (MDR) Candida glabrata. Case Presentation. A 52-year-old man has undergone an extensive small bowel resection with the length of the remaining bowel which was less than 40 cm who became a candidate for transplantation. Four months after transplantation, the patient experienced severe bloody diarrhea with abdominal distension. Ileoscopy and colonoscopy did not show neither pathological change and rejection nor cytomegalovirus (CMV) infection posttransplantation. Abdomen computed tomography showed diffuse moderate small bowel wall thickening. After detection of budding yeast in the stool samples, stool culture was positive for Candida, DNA was extracted, and ITS1-5.8s-ITS2 region of the fungal agent was amplified. Sequencing analysis of PCR and antifungal susceptibility testing revealed that this isolate was multidrug-resistant C. glabrata. Besides, there was no evidence for other pathogens known to cause infection in various laboratory tests. Immediate antifungal treatments with caspofungin remained unsuccessful, and on the eighteenth day of admission, the patient expires with septic shock.

Conclusion

These findings highlight the challenging management of candidiasis in patients with small bowel transplantation. Infectious diseases due to MDR organisms have emerged as a vital clinical problem in this patient population.

Azole Antifungal Resistance in Candida albicans and Candida glabrata Isolated from Vulvovaginal Candidiasis Patients

Background: Vulvovaginal candidiasis (VVC) is the most frequent fungal disorder in healthy and normal women. Objectives: The aim of this study was to evaluate the in vitro antifungal susceptibility of clinical isolates Candida albicans and Candida glabrata, the two most common candida species in Iranian patients with VVC. Methods: One hundred and eight clinical isolates of candida, including; C. albicans (n = 77) and C. glabrata: (n = 31) were isolated from the 108 patients with VVC. The in vitro activity of caspofungin (CAS), amphotericin B (AMB), voriconazole (VRC), itraconazole (ITC), fluconazole (FLC), and nystatin (NYS) were determined according to the CLSI M27-A3 and CLSI M27-S4. Results: Our results were shown 8 (25.8 %) and 6 (7.8 %) C. glabrata and C. albicans isolates resistance to FLU, respectively. Furthermore, resistance to VRC and ITC were observed in 8.4%, and 3.7% of all isolates, and six isolates (5.6%) had intermediate MIC to CAS. Conclusions: We reported 8 (25.8 %) and 6 (7.8 %) C. glabrata and C. albicans isolates resistance to FLU, respectively. Furthermore, resistance to VRC and ITC were observed in 8.4% and 3.7% of all isolates, respectively.

Species Distribution and Antifungal Susceptibility Pattern of Candida Recovered from Intensive Care Unit Patients, Vietnam National Hospital of Burn (2017-2019)

INTRODUCTION

Candida species is the most common cause of invasive fungal infection. With the wide variation in species distribution and antifungal susceptibility of causative agents, local epidemiological profiles are needed to provide effective guidelines for the treatment of invasive candidiasis.

OBJECTIVE

To find out the species distribution and antifungal susceptibilities of Candida strains isolated from patients in an intensive care unit (ICU) of Vietnam.

METHODS

All patients in ICU of Vietnam National Hospital of Burn with Candida isolation reported from January 2017 to December 2019 were retrospectively studied. Species identification and antifungal susceptibility testing were performed using VITEK 2 Compact. The identification was reconfirmed by sequencing of the internal transcribed spacer regions when needed.

RESULTS

A total of 186 yeasts belonging to ten species were collected. The most common agent was C. tropicalis (45.7%), followed by C. albicans (42.4%), and C. parapsilosis (7.53%). The isolated yeasts showed less susceptibility to fluconazole (resistant rate R 10.7%) than to micafungin, caspofungin, flucytosine and amphotericin B (R 0%, 0.6%, 2.3% and 3.4%, respectively, p < 0.05). C. albicans isolates were more susceptible to fluconazole (R 5.2%) than C. tropicalis (R 15.7%). Resistance to voriconazole was seen only among C. albicans (3.9%) and C. tropicalis isolates (9.9%).

CONCLUSION

Non-albicans species (especially C. tropicalis) is the predominant species, and there is a significant proportion of isolates with reduced susceptibility to azole but not to echinocandin.

Vaginal candidiasis in Konya area: Etiology, risk factors, virulence patterns, and antifungal susceptibility

Vulvovaginal candidiasis (VVC), a common genital tract infection, is known to affect millions of women worldwide. In this study, it was aimed to determine the prevalence, virulence, possible risk factors and antifungal susceptibility model of Candida species. Vaginal swab samples were taken from patients aged 18 years and older who presented to the gynecology outpatient clinic with signs and symptoms suggestive of vulvovaginitis. Demographic data were recorded using a questionnaire. Standard microbiological methods were used for the identification of the isolates. Broth microdilution method was used to determine the antifungal susceptibility of Candida isolates. Virulence factors of Candida strains were determined by performing proteinase, phospholipase, hemolytic and biofilm activity tests. Sequencing of the isolates identified as Candida were performed using ITS 1-4 primers. Vaginal discharge (OR: 3.365; 95% CI: 1.595-7.101), burning complaint (OR: 9.098; 95% CI: 2.284-36.232) and history of allergy (OR: 3.396; 95% CI: 0.968) were risk factors. The results showed that the most common isolated strain was Candida albicans (57%). It was found that the prevalence of C. glabrata remained at 26%, 44 of the C. albicans isolates presented proteinase, 35 had phospholipase, 47 had biofilm, and 47 had hemolytic activity. In this study, susceptible dose-dependent and resistant rates of all Candida strains were found for fluconazole as 9% and 16%, respectively. Host and organism-related factors should be considered in the clinical treatment of VVC, and continuous monitoring of changes in the prevalence of Candida species and susceptibility rates is required for effective antifungal therapy.

Green Approach to Overcome the Resistance Pattern of Candida spp. Using Biosynthesized Silver Nanoparticles Fabricated by Penicillium chrysogenum F9

Candida species are the most common causative agents responsible for the majority of morbidity as well as mortality rates due to invasive fungal infections worldwide. In this study, a green approach was developed to control the pathogenic Candida spp. isolated from clinical samples, and prior data collections, ethics approval was obtained. Sixty candida isolates were obtained from the different device-associated infections and identified as Candida albicans, Candida tropicalis, Candida krusei, Candida parapsilosis, and Candida glabrata with prevalence rates 41.6, 38.3, 8.3, 6.6, and 5%, respectively. On the other hand, silver nanoparticles (Ag-NPs) were extra-cellular synthesized by biomass filtrate of previously identified Penicillium chrysogenum strain F9. The physico-chemical characterizations of biosynthesized Ag-NPs were assessed by using UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) patterns, transmission electron microscope (TEM), dynamic light scattering (DIS), and zeta potential (ζ) analysis. Data revealed successful synthesis of crystallographic spherical Ag-NPs with average size 18 to 60 nm at maximum absorption peak 415 nm. FT-IR analysis confirmed the presence of functional groups related to reduction, capping, and stabilizing Ag-NPs. The DLS analysis showed that NPs were homogenous and stable with poly-dispersity index (PDI) and ζ value 0.008 and - 21 mV, respectively. Susceptibility pattern analysis revealed that sixty Candida isolates (100%) were susceptible to Ag-NPs as compared to 25 isolates (41.6%), and 30 isolates (50%) were susceptible to fluconazole and amphotericin B, respectively. Interestingly, 30 Candida isolates (50%) were resistant to amphotericin B, which are more than those recorded for fluconazole (17 isolates with percent 28.3%), while 18 candida isolates (30%) were susceptible dose-dependent to fluconazole. The recorded minimum inhibitory concentration _50/90 (MIC_50/90) was 62.5/125, 16/64, and 1/4 for Ag-NPs, fluconazole, and amphotericin B, respectively. However, green synthesized Ag-NPs can be used to overcome the resistance pattern of Candida spp., and recommended as an anti-candida agent.

The prevalence and clinical significance of microcolonies when tested according to contemporary interpretive breakpoints for fluconazole against Candida species using E-test

Changes in the interpretive-breakpoints for antifungals against various Candida species have raised the need to examine the significance of the phenomenon of the growth of microcolonies in agar diffusion inhibition zones, which has generally been considered negligible. The objective was to determine the incidence of cases in which microcolonies demonstrate fluconazole resistance according to current interpretive-breakpoints and whether their growth is associated with therapeutic failure. The fluconazole minimum inhibitory concentrations (MICs) of 100 blood culture isolates of Candida were performed by E-test on Roswell Park Memorial Institute (RPMI) agar and examined for the appearance of microcolonies. Fluconazole MICs of microcolonies were then determined over three generations. The significance of the phenomenon of microcolonies was determined according to clinical data retrieved from electronic files. Microcolonies were a common phenomenon among Candida isolates following incubation on RPMI agar, with a higher frequency among C. albicans isolates as compared to non-albicans Candida across generations (57-93% vs 31-93%, respectively) and a similar fluconazole susceptibility rate over three generations. The rate of microcolonies was similar in both patients with successful and unsuccessful outcome (41% vs 42%, respectively). Microcolonies are a common phenomenon. No increase in MIC was demonstrated throughout three generations of microcolony inoculation on RPMI, and no difference in clinical outcome was observed.

Repurposing approach identifies pitavastatin as a potent azole chemosensitizing agent effective against azole-resistant Candida species

The limited number of antifungals and the rising frequency of azole-resistant Candida species are growing challenges to human medicine. Drug repurposing signifies an appealing approach to enhance the activity of current antifungal drugs. Here, we evaluated the ability of Pharmakon 1600 drug library to sensitize an azole-resistant Candida albicans to the effect of fluconazole. The primary screen revealed 44 non-antifungal hits were able to act synergistically with fluconazole against the test strain. Of note, 21 compounds, showed aptness for systemic administration and limited toxic effects, were considered as potential fluconazole adjuvants and thus were termed as “repositionable hits”. A follow-up analysis revealed pitavastatin displaying the most potent fluconazole chemosensitizing activity against the test strain (ΣFICI 0.05) and thus was further evaluated against 18 isolates of C. albicans (n = 9), C. glabrata (n = 4), and C. auris (n = 5). Pitavastatin displayed broad-spectrum synergistic interactions with both fluconazole and voriconazole against ~89% of the tested strains (ΣFICI 0.05–0.5). Additionally, the pitavastatin-fluconazole combination significantly reduced the biofilm-forming abilities of the tested Candida species by up to 73%, and successfully reduced the fungal burdens in a Caenorhabditis elegans infection model by up to 96%. This study presents pitavastatin as a potent azole chemosensitizing agent that warrant further investigation.

Self-nanoemulsifying drug delivery system to improve transcorneal permeability of voriconazole: in-vivo studies

OBJECTIVE

This study investigates the effectiveness of self-nanoemulsifying drug delivery system (SNEDDS) in improving voriconazole transcorneal permeability.

METHODS

Voriconazole-SNEDDS was prepared with isopropyl myristate, PEG 400, Tween 80^® and Span 80^® and was subjected for physicochemical characterization after reconstitution with NaCl 0.9% (1/9; v/v). In-vitro antifungal activity was assessed and compared with the marketed formulation. In-vivo studies, namely ocular irritation test via modified Draize test and pharmacokinetic study, were investigated using rabbit as animal model.

KEY FINDINGS

Voriconazole-SNEDDS presented a droplet size of 21.353 ± 0.065 nm, a polydispersity index of 0.123 ± 0.003, a pH of 7.205 ± 0.006 and an osmolarity of 342.667 ± 2.517 mOsmol/l after reconstitution with NaCl 0.9%. Voriconazole-SNEDDS minimum inhibitory concentration (MIC₉₀ ) was similar to the one of marketed formulation for Candida species while it was significantly lower (P < 0.001) for Aspergillus fumigatus. Draize test revealed that Voriconazole-SNEDDS was safe for ocular administration. Voriconazole maximum concentration (5.577 ± 0.852 µg/ml) from SNEDDS was higher than marketed formulation (C_max  = 4.307 ± 0.623 µg/ml), and the T_max was delayed to 2 h. The area under the concentration-time curve value of Voriconazole-SNEDDS was improved by 2.419-fold.

CONCLUSION

Our results suggest that SNEDDS is a promising carrier for voriconazole ocular delivery and this encourages further clinical studies.

Expression of ERG11 and efflux pump genes CDR1, CDR2 and SNQ2 in voriconazole susceptible and resistant Candida glabrata strains

Candida glabrata causes difficult to treat invasive candidiasis due to its antifungal resistance, mainly to azoles. The aim of the present work was to study the role of the genes ERG11, CDR1, CDR2, and SNQ2 on the resistance to voriconazole (VRC) in a set of C. glabrata strains with known in vitro and in vivo susceptibility to this drug. Eighteen clinical isolates of C. glabrata were exposed in vitro to VRC, and the expression of the cited genes was quantified by real time quantitative polymerase chain reaction (q-PCR). In addition, the ERG11 gene was amplified and sequenced to detect possible mutations. Ten synonymous mutations were found in 15 strains, two of them being reported for the first time; however, no amino acid changes were detected. ERG11 and CDR1 were the most expressed genes in all the strains tested, while the expression of CDR2 and SNQ2 was modest. Our results show that gene expression does not directly correlate with the VRC MIC. In addition, the expression profiles of ERG11 and efflux pump genes did not change consistently after exposure to VRC. Although individual analysis did not result in a clear correlation between MIC and gene expression, we did observe an increase in ERG11 and CDR1 expression in resistant strains. It is of interest that considering both in vitro and in vivo results, the slight increase in such gene expression correlates with the observed resistance to VRC.

Evaluation of the Antifungal Activity of Mentha x piperita (Lamiaceae) of Pancalieri (Turin, Italy) Essential Oil and Its Synergistic Interaction with Azoles

The promising antimicrobial activity of essential oils (EOs) has led researchers to use them in combination with antimicrobial drugs in order to reduce drug toxicity, side effects, and resistance to single agents. Mentha x piperita, known worldwide as “Mentha of Pancalieri”, is produced locally at Pancalieri (Turin, Italy). The EO from this Mentha species is considered as one of the best mint EOs in the world. In our research, we assessed the antifungal activity of “Mentha of Pancalieri” EO, either alone or in combination with azole drugs (fluconazole, itraconazole, ketoconazole) against a wide panel of yeast and dermatophyte clinical isolates. The EO was analyzed by GC-MS, and its antifungal properties were evaluated by minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) parameters, in accordance with the CLSI guidelines, with some modifications. The interaction of EO with azoles was evaluated through the chequerboard and isobologram methods. The results suggest that this EO exerts a fungicidal activity against yeasts and a fungistatic activity against dermatophytes. Interaction studies with azoles indicated mainly synergistic profiles between itraconazole and EO vs. Candida spp., Cryptococcus neoformans, and Trichophyton mentagrophytes. Thus, the “Mentha of Pancalieri” EO may act as a potential antifungal agent and could serve as a natural adjuvant for fungal infection treatment.

Epidemiology and antifungal susceptibility testing of non-albicansCandida species colonizing mucosae of HIV-infected patients in Yaoundé (Cameroon)

Non-albicans Candida (NAC) species have emerged as potent pathogenic yeasts among HIV-infected patients. Authors evaluated the epidemiology and antifungal susceptibility testing of non-albicansCandida species colonizing Yaoundé (capital of the Republic of Cameroon, Central Africa) HIV-infected patients. The mucosal specimens were collected and submitted to the mycological diagnosis. Yeast isolates were identified by the Matrix Assisted Laser Desorption Ionisation - Time of Flight Mass Spectrometry (MALDI-TOF MS). The antifungal susceptibility testing was achieved by the CLSI-M27 protocols, and the interpretation of clinical break points (CBPs) and epidemiological cutoff values were in accordance with the CLSI-M60 and M59 recommendations. Four hundred and two patients were recruited and 1218 samples collected. The colonisation frequency was 24.1% and 304 yeasts isolated. Yeast isolates were 113 (37.2%) C. albicans, 2 (0.7%) C. africana and 172 (56.6%) NAC isolates. The NAC isolates were grouped into 13 species including C. krusei (18.1%), C. glabrata (10.9%), C. tropicalis (8.5%) and C. parapsilosis (5.9%) as the major ones. All the isolates appeared to be wild-type for amphotericin B and itraconazole. One (1/33) isolate of C. glabrata was resistant to fluconazole. C. arapsilosis isolates appeared all susceptible to fluconazole. C. tropicalis isolates presented 50% (13/26) resistance to fluconazole. The achieved results bring out new insights about epidemiology of NAC species in Cameroon. The results also highlight the resistance of NAC species to current antifungal drugs.

Successful eradication of chronic symptomatic Candida krusei urinary tract infection with increased dose micafungin in a liver and kidney transplant recipient: Case report and review of the literature

Treatment of symptomatic candiduria is notoriously challenging because of the limited repository of antifungals that achieve adequate urinary concentrations. Fluconazole, amphotericin B-based products, and flucytosine are established treatment options for most Candida species. Candida krusei exhibits intrinsic resistance to fluconazole and decreased susceptibility to amphotericin B and flucytosine. In transplant patients, both amphotericin B-based products and flucytosine are less desirable because of their toxicities. Other triazole antifungals are unappealing because they do not achieve adequate urinary concentrations, have multiple toxicities, and interact with transplant-related immunosuppressive medications. Echinocandins are well-tolerated but have been traditionally deferred in the treatment of symptomatic funguria because of their poor urinary concentrations but there is a small but emerging body of literature supporting their use. Here, we present a case of successful eradication of chronic symptomatic C krusei urinary tract infection with micafungin 150 milligrams daily in a liver and kidney transplant recipient, and we review the literature on treatment of symptomatic candiduria.

Determination of antimicotic susceptibility pattern of Candida species isolated from patients with symptomatic candiduria

Background

The present study was conducted to determine antimicotic susceptibility of Candida species (sp.) from patients with symptomatic candiduria.

Materials and Methods

Identification of Candida sp. and determination of efficacy of most routine antifungals were done using polymerase chain reaction-restriction fragment length polymorphism method and E-test, respectively.

Results

The results from susceptibility test reveal that caspofungin and amphotericin B have high antifungal activity against both albicans (100% and 96%, respectively) and nonalbicans (95.11% and 72.72%, respectively) isolates.

Conclusion

The present study suggests that caspofungin and amphotericin B have the excellent ability to eradicate both Candida groups that showed decreased susceptibility to other compounds.

Genotyping of Candida albicans isolated from animals using 25S ribosomal DNA and ALT repeats polymorphism in repetitive sequence

Background and Purpose:

Candida albicans is the most prevalent Candida species isolated from animals. Candidiasis can be systemic in animals or may affect a single organ, such as the mouth, urinary tract, and skin. The aim of the present study was to determine the genetic diversity of C. albicans isolated from different animals and investigate the presence of a relationship between host specificity and genetic typing of C. albicans.

Materials and Methods:

For the purpose of the study, DNA extraction was performed on 27 clinical isolates of C. albicans obtained from animals. Subsequently, they were subjected to 25S ribosomal DNA amplification and ALT repeats in repetitive sequences (RPSs). The minimum inhibitory concentrations of fluconazole, ketoconazole, clotrimazole, nystatin, amphotericin B, and caspofungin were determined using the microdilution method based on the Clinical and Laboratory Standards Institute M27-S4 standard.

Results:

Out of 27 C. albicans strains, 11, 6, 5, and 5 cases were recognized as genotypes A (40.8%), E (22.2%), B (18.5%), and C (18.5%), respectively, through amplification using AS-I, which revealed 17 different types of C. albicans. By combining the two typing methods, 27 C. albicans strains were finally divided into 22 genotypes.

Conclusion:

Different genotypes showed genetic diversity among the C. albicans strains isolated from animal sources. The results revealed no special genotype relationship according to the host, anatomical source of isolation, and antifungal susceptibility.

Activity of antifungal agents alone and in combination against echinocandin-susceptible and -resistant Candida parapsilosis strains

BACKGROUND

Candida parapsilosis may acquire resistance to echinocandins, a fact that prompts the search for new therapeutic options.

AIMS

The present study aimed to evaluate the in vitro activity of antifungal agents, alone and in combination, against four groups of C. parapsilosis strains: (1) echinocandin-susceptible (ES) clinical isolates (MIC ≤ 2μg/ml), (2) anidulafungin-resistant strains (MIC ≥ 8μg/ml), (3) caspofungin-resistant strains (MIC ≥ 8μg/ml), and (4) micafungin-resistant strains (MIC ≥ 8μg/ml).

METHODS

Antifungal interactions were evaluated by a checkerboard micro-dilution method. The determination of the MIC to each drug for every isolate according to the Clinical and Laboratory Standards Institute documents M27 (2017) and M60 (2017) was also done.

RESULTS

The echinocandins-resistant (ER) strains showed higher MICs to the tested antifungals than the ES strains, except for amphotericin B, for which the ER groups remained susceptible.

CONCLUSIONS

Most combinations showed indifferent interactions. The use of monotherapy still seems to be the best option. As resistance to echinocandins is an emergent phenomenon, further studies are required to provide clearer information on the susceptibility differences between strains to these antifungal agents.

Clinical characteristics of Candida tropicalis fungaemia with reduced triazole susceptibility in Taiwan: a multicentre study

Candida tropicalis is the second most common Candida species causing fungaemia in Taiwan, and decreased susceptibility to fluconazole has been reported. This study analysed the clinical characteristics of adult patients with C. tropicalis fungaemia and the antifungal susceptibilities of isolates at five tertiary hospitals in Taiwan (1 July 2011 to 30 June 2014). A standardised case record form was used retrospectively to collect demographic, clinical and microbiological characteristics, antifungal treatment and outcomes. MICs of non-duplicate isolates were determined using Sensititre^TM YeastOne^TM and were interpreted using cut-off values recommended by the CLSI. A total 248 patients were diagnosed over the study period; 30-day crude mortality was 52.0%. Multivariate analysis showed that high Charlson comorbidity index ≥4 (OR = 2.09, 95% CI 1.22-3.59; P = 0.008), neutropenia (OR = 4.61, 95% CI 1.42-15.00; P = 0.011) and treatment with an azole-based regimen (OR = 0.39, 95% CI 0.17-0.90; P = 0.028) were significantly associated with 30-day mortality. A total of 33.9% of isolates were non-susceptible to fluconazole (MIC₅₀, 2 mg/L; MIC₉₀, 16 mg/L; MIC range, 0.25 to >256 mg/L), whilst 56.9% to voriconazole (MIC₅₀, 0.25 mg/L; MIC₉₀, 1 mg/L; MIC range, 0.015 to >8 mg/L) according to CLSI clinical breakpoints. There was no significant correlation between overall mortality and MICs of fluconazole or voriconazole. This study showed high mortality in patients with C. tropicalis fungaemia, and azole-based antifungal treatment could improve outcomes regardless of fluconazole MICs of infecting isolates compared with patients without any treatment within 48 h.

Functions of Candida albicans cell wall glycosidases Dfg5p and Dcw1p in biofilm formation and HOG MAPK pathway

Background

Candida albicans is a commensal fungus that inhabits the oral mucosal surface and causes oral and systemic candidiasis. Oral candidiasis most commonly occurs in patients with AIDS, denture wearers and newborn children. Systemic candidiasis occurs mainly in immunocompromised patients and patients admitted to hospitals for prolonged periods. C. albicans homologous genes, DFG5 and DCW1, encode for two closely related cell wall proteins with putative glycosyltransferase enzyme activity and C-terminal GPI-anchors. Past studies have shown that individual DFG5 and DCW1 mutations are viable but simultaneous deletion of DFG5 and DCW1 in C. albicans results in lethality. However, the exact functions of these cell wall based enzymes, which represent potential drug targets, are not understood.

Methods

C. albicans DFG5/DCW1 heterologous and conditional double mutant strains were assessed for growth and biofilm formation in comparison to wild type and parental strains. Cell wall and heat stress susceptibility of the mutant and control strains were assessed using agar spotting assays. Growth was assessed under normal and osmotic stress conditions along with light microscopy imaging. Biofilm dry weight and microscopic imaging analysis of biofilms was performed. Hypha formation in response to serum was analyzed using light microscopy imaging. Western blot analysis of mutant strains and control strains was performed to assess Hog1 basal levels and phosphorylation status.

Results

Analysis of the heterologous mutants indicated that Dfg5p is more important for growth while Dcw1p appeared to play a role in cell wall integrity response. The conditional double mutant was observed to be less resistant to cell wall stress. However, growth of the mutants was similar under control and osmotic stress conditions. The mutants were also able to grow similar to wild type under heat stress. Biofilm formation was reduced in the mutants where DFG5 was deleted or suppressed. Hyphal morphogenesis was reduced although germ tube formation was observed in the biofilms of the mutant strains. Basal Hog1 protein levels were reduced or absent in the DFG5 and DCW1 mutants. However, osmotic stress was able to induce Hog1 protein levels comparable to wild type. Hog1 phosphorylation appeared to be slightly reduced although not significantly. In addition to biofilm assays, serum dose response imaging analysis indicated that hyphae formation in DFG5 and DCW1 mutants was defective.

Conclusions

These data indicate that DFG5 and DCW1 are required for hyphal morphogenesis and biofilm formation in C. albicans. These functions may be regulated via basal Hog1 MAPK which is required for transcriptional regulation of chitin synthesis.

Fatty Acids Effect on Lipase and Biosurfactant Induction in Rhodotorula Glutinis CMGB-RG5

Fatty acids represent important substrates for obtaining microbial lipases and biosurfactants. The yeast strain CMGBRG5 was identified as Rhodotorula glutinis using the BIOLOG MicroLog System. The opacity screening tests showed that R. glutinis CMGB-RG5 was able to produce lipases in presence of 1% Tween 80 after three days of incubation. Lipase induction was estimated as cell growth in presence of Tween 80, Tween 20, olive oil and tributyrin. After 48 hours, best results were obtained in presence of butyric acid, respectively, oleic acid: 2.2 × 107 cells/ml on tributyrin and 1.0 × 107 cells/ml on olive oil. Biosurfactant production was evaluated as emulsification index (E24%). After one week, high E24 values were obtained on fried sunflower oil (53%) and olive oil (35%). Crude and concentrated biosurfactants were tested against nine Candida strains. Best antimicrobial activity was observed for [20X] biosurfactants against C. tropicalis, C. guilliermondii and C. krusei. In conclusion, R. glutinis CGB-RG5 shows high potential for using fatty acids from various sources as unique carbon substrates for synthesis of biocompounds with high economic and biotechnological value.

Antifungal Susceptibility and Clinical Outcome in Neonatal Candidiasis

BACKGROUND

Invasive candidiasis is an important cause of sepsis in extremely low birth weight infants (ELBW, < 1000 g), is often fatal, and frequently results in neurodevelopmental impairment (NDI) among survivors. We sought to assess the antifungal minimum inhibitory concentration (MIC) distribution for Candida in ELBW infants and evaluate the association between antifungal resistance and death or NDI.

METHODS

This was a secondary analysis of a National Institute of Child Health and Human Development Neonatal Research Network study. MIC values were determined for fluconazole, amphotericin B and micafungin. NDI was assessed at 18-22 months adjusted age using the Bayley Scales of Infant Development. An infant was defined as having a resistant Candida isolate if ≥ 1 positive cultures from normally sterile sites (blood, cerebrospinal fluid, or urine) were resistant to ≥ 1 antifungal agent. In addition to resistance status, we categorized fungal isolates according to MIC values (low and high). The association between death/NDI and MIC level was determined using logistic regression, controlling for gestational age and Bayley Scales of Infant Development (II or III).

RESULTS

Among 137 ELBW infants with IC, MICs were determined for 308 isolates from 110 (80%) infants. Three Candida isolates from 3 infants were resistant to fluconazole. None were resistant to amphotericin B or micafungin. No significant difference in death, NDI, or death/NDI between groups with low and high MICs was observed.

CONCLUSIONS

Antifungal resistance was rare among infecting Candida isolates, and MIC level was not associated with increased risk of death or NDI in this cohort of ELBW infants.

Candida Infections and Therapeutic Strategies: Mechanisms of Action for Traditional and Alternative Agents

The Candida genus comprises opportunistic fungi that can become pathogenic when the immune system of the host fails. Candida albicans is the most important and prevalent species. Polyenes, fluoropyrimidines, echinocandins, and azoles are used as commercial antifungal agents to treat candidiasis. However, the presence of intrinsic and developed resistance against azole antifungals has been extensively documented among several Candida species. The advent of original and re-emergence of classical fungal diseases have occurred as a consequence of the development of the antifungal resistance phenomenon. In this way, the development of new satisfactory therapy for fungal diseases persists as a major challenge of present-day medicine. The design of original drugs from traditional medicines provides new promises in the modern clinic. The urgent need includes the development of alternative drugs that are more efficient and tolerant than those traditional already in use. The identification of new substances with potential antifungal effect at low concentrations or in combination is also a possibility. The present review briefly examines the infections caused by Candida species and focuses on the mechanisms of action associated with the traditional agents used to treat those infections, as well as the current understanding of the molecular basis of resistance development in these fungal species. In addition, this review describes some of the promising alternative molecules and/or substances that could be used as anticandidal agents, their mechanisms of action, and their use in combination with traditional drugs.

Do we need to adopt antifungal stewardship programmes?

Background

Although antimicrobial stewardship programmes are one of the highest priorities in healthcare systems and many articles have been published, few refer to the implementation of antifungal stewardship and highlight specific points on which efforts should be focused.

Objective

To assess the percentage of patients with confirmed candidaemia in whom de-escalation was conducted, and the economic impact of step-down or step-up antifungal therapy. Additionally, we attempted to estimate the potential increase in drug minimum inhibitory concentrations or to detect resistant strains of Candida species.

Methods

We selected, retrospectively, patients who had received systemic antifungal therapy between 2011 and 2016 for documented candidaemia. Statistical analysis and diagrams were used to assess the results.

Results

Of 157 patients with confirmed candidaemia, 58 received azoles, 74 echinocandinsand 18 liposomal amphotericin B for empirical therapy. 51 patients were eligible to step-down to fluconazole but only 23 patients did so. Furthermore, in nine patients unjustified step-up from fluconazole to echinocandins or liposomal amphotericin B was carried out. The additional cost incurred bythe healthcare system due to high prices of echinocandins and liposomal amphotericin B in comparison with fluconazole was€211 837. Interestingly, it was found that one strain of C. albicans and two strains of C. glabrata were resistant to echinocandins.

Conclusion

The presence of a multidisciplinary team, including an infection control specialist and a clinical pharmacist, would limit the prescription of advanced antifungal agents as empirical therapy. Moreover, this team would control the de-escalation process-where applicable-leading to a reduction in costs and, probably, a decrease in the emergence of resistant Candida species. These facts contribute to the broader discussion on the adoption of antifungal stewardship programmes.

A phase 2, randomized, double-blind, placebo-controlled, dose-ranging study to evaluate the efficacy and safety of orally administered VT-1161 in the treatment of recurrent vulvovaginal candidiasis

BACKGROUND

Lanosterol demethylase is an enzyme that is essential for fungal growth and catalyzes an early step in the biosynthetic pathway of ergosterol, which is a sterol that is required for fungal cell membrane formation and integrity. Lanosterol demethylase is the molecular target of the class of drugs referred to as "azole antifungals." VT-1161 is a novel, oral, selective inhibitor of fungal lanosterol demethylase and is being developed for the treatment of recurrent vulvovaginal candidiasis.

OBJECTIVE

We evaluated the efficacy and safety of 4 dosing regimens of oral VT-1161 compared with placebo in women with recurrent vulvovaginal candidiasis, which was defined as at least 3 symptomatic episodes of acute vulvovaginal candidiasis within a 12-month period.

STUDY DESIGN

Two hundred fifteen women with a documented history of recurrent vulvovaginal candidiasis and who, at screening, were experiencing an episode of acute vulvovaginal candidiasis (acute vulvovaginal candidiasis; composite vulvovaginal signs and symptoms score of ≥3 and a positive potassium hydroxide test for yeast) were enrolled. After treatment of the acute infection with fluconazole, subjects were assigned randomly to 1 of 5 treatment regimens: (1) VT-1161 150 mg once daily for 7 days, then 150 mg once weekly for 11 weeks, followed by a once-weekly dose of placebo for 12 weeks; (2) VT-1161 300 mg once daily for 7 days, then 300 mg once weekly for 11 weeks, followed by a once-weekly dose of placebo for 12 weeks; (3) VT-1161 150 mg once daily for 7 days, then 150 mg once weekly for 23 weeks; (4) VT-1161 300 mg once daily for 7 days, then 300 mg once weekly for 23 weeks; or (5) a matching placebo regimen for 24 weeks. The primary efficacy outcome was the proportion of subjects with ≥1 culture-verified acute vulvovaginal candidiasis episodes through week 48.

RESULTS

In the intent-to-treat population, the proportion of subjects with ≥1 acute vulvovaginal candidiasis episodes ranged from 0-7% across the 4 VT-1161 arms vs 52% in the placebo arm, with all arms achieving statistical significance vs placebo. VT-1161 was well-tolerated with a favorable safety profile, and the incidence of adverse events was lower in all VT-1161 arms compared with placebo. In addition, no patient in any VT-1161 arm discontinued the study early because of an adverse event or laboratory abnormality. There was also no evidence of an adverse effect of VT-1161 on liver function or electrocardiogram recordings.

CONCLUSION

In this study, VT-1161 was shown to be efficacious and safe in the treatment of patients with recurrent vulvovaginal candidiasis. These data strongly support further clinical investigation of VT-1161 for the treatment of recurrent vulvovaginal candidiasis.

Antifungal susceptibility testing results of New Zealand yeast isolates, 2001-2015: Impact of recent CLSI breakpoints and epidemiological cut-off values for Candida and other yeast species

OBJECTIVES

We reviewed the antifungal susceptibility testing results of local yeast isolates (2001-2015) to record the impact of recently updated interpretive criteria and epidemiological cut-off values (ECVs) for yeast species.

METHODS

Susceptibility testing was performed using Sensititre^® YeastOne^®. The results were interpreted following CLSI criteria or YeastOne-derived ECVs.

RESULTS

A total of 2345 isolates were tested; 62.0% were from sterile body sites or tissue. Application of new CLSI interpretative criteria for fluconazole increased the proportion of non-susceptible isolates of Candida parapsilosis, Candida tropicalis and Candida glabrata (P≤0.03 for all species). For voriconazole, the greatest increase was for C. tropicalis (P<0.0001). Application of new CLSI interpretive criteria for caspofungin increased the proportion of non-susceptible isolates for C. glabrata and Pichia kudriavzevii (P<0.0001 for both). The new amphotericin ECV (≤2mg/L) did not reveal any non-wild-type (non-WT) isolates in the five species covered. YeastOne itraconazole ECVs detected 2%, 5% and 6% non-WT isolates for P. kudriavzevii, C. tropicalis and C. glabrata, respectively. No itraconazole non-WT isolates of Clavispora lusitaniae were detected.

CONCLUSIONS

Whilst most results are similar to other large surveys of fungal susceptibility, the new CLSI interpretive criteria significantly altered the proportion of non-susceptible isolates to fluconazole, voriconazole and caspofungin for several Candida spp. Application of CLSI and YeastOne-derived ECVs revealed the presence of a low proportion of non-WT isolates for many species. The results serve as a baseline to monitor the susceptibility of Candida and other yeast species in New Zealand over time.

Chemical composition, antioxidant activity and antifungal effects of five Iranian essential oils against Candida strains isolated from urine samples

Systemic candidiasis has become an emerging fungal infection in recent years. Anti-Candida resistance to conventional antifungal agents has subsequently increased. This study reported the chemical composition, antioxidant and anti-Candida activity of Origanum majorana, Artemisia dracunculus, Cymbopogon citrate, Cinnamomum verum and Caryophyllus aromaticus essential oils. Different Candida species, from urine tracts of hospitalized patients, were included to be challenged with understudied essential oils. Chemical compositions were determined using gas chromatography/mass spectroscopy (GC/MS) analysis and antioxidant activity was measured using DDPH assay. MIC of these essential oils was evaluated using broth micro-dilution test. Caryophyllus aromaticus had the highest antioxidant activity while the lowest antioxidant activity was for Artemisia dracunculus. MICs of Cinnamomum verum, Caryophillium aromaticus, Artemisia dracunculus, Origanum vulgare and Cymbopogon citratus essential oils ranged from 125 to 175μg/mL (mean value: 147.7±25.5μg/mL), 700 to 1000μg/mL (mean value: 740.9±105.4μg/mL), 1000 to 2000μg/mL (mean value: 1454.5±509.6μg/mL), 173 to 350μg/mL (mean value: 208±55.8μg/mL) and 125 to 175μg/mL (mean value: 156.8±24.6μg/mL) for different Candida species, respectively. In general, natural compounds are suitable to be used as anti-Candida and antioxidant agents. However in this stage, these compounds could be applied as supplementary agents along with conventional antifungal drugs.

Identification and susceptibility of clinical isolates of Candida spp. to killer toxins

Although invasive infections and mortality caused by Candida species are increasing among compromised patients, resistance to common antifungal agents is also an increasing problem. We analyzed 60 yeasts isolated from patients with invasive candidiasis using a PCR/RFLP strategy based on the internal transcribed spacer (ITS2) region to identify different Candida pathogenic species. PCR analysis was performed from genomic DNA with a primer pair of the ITS2-5.8S rDNA region. PCR-positive samples were characterized by RFLP. Restriction resulted in 23 isolates identified as C. albicans using AlwI, 24 isolates as C. parapsilosis using RsaI, and 13 as C. tropicalis using XmaI. Then, a group of all isolates were evaluated for their susceptibility to a panel of previously described killer yeasts, resulting in 75% being susceptible to at least one killer yeast while the remaining were not inhibited by any strain. C. albicans was the most susceptible group while C. tropicalis had the fewest inhibitions. No species-specific pattern of inhibition was obtained with this panel of killer yeasts. Metschnikowia pulcherrima, Pichia kluyveri and Wickerhamomyces anomalus were the strains that inhibited the most isolates of Candida spp.

Investigating cross-contamination by yeast strains from dental solid waste to waste-handling workers by DNA sequencing

Trying to widen the discussion on the risks associated with dental waste, this study proposed to investigate and genetically compare yeast isolates recovered from dental solid waste and waste workers. Three samples were collected from workers' hands, nasal mucosa, and professional clothing (days 0, 30, and 180), and two from dental waste (days 0 and 180). Slide culture, microscopy, antifungal drug susceptibility, intersimple sequence repeat analysis, and amplification and sequencing of internal transcribed spacer regions were performed. Yeast strains were recovered from all waste workers' sites, including professional clothes, and from waste. Antifungal susceptibility testing demonstrated that some yeast recovered from employees and waste exhibited nonsusceptible profiles. The dendrogram demonstrated the presence of three major clusters based on similarity matrix and UPGMA grouping method. Two branches displayed 100% similarity: three strains of Candida guilliermondii isolated from different employees, working in opposite work shifts, and from diverse sites grouped in one part of branch 1 and cluster 3 that included two samples of Candida albicans recovered from waste and the hand of one waste worker. The results suggested the possibility of cross‐contamination from dental waste to waste workers and reinforce the need of training programs focused on better waste management routines.

Impact of inappropriate antifungal therapy according to current susceptibility breakpoints on Candida bloodstream infection mortality, a retrospective analysis

BACKGROUND

The mortality of Candida Bloodstream Infection (CBSI) remains high. Antifungal susceptibility breakpoints were recently updated for Candida species, the impact remains unknown. In this study we evaluated the impact of inappropriate antifungal treatment according to recent breakpoints on 30-day mortality of CBSI.

METHODS

From June 2008 to July 2014, data on CBSI episodes from two tertiary-care centers, treated > 72 h were analyzed. Antifungal therapy and 30-day mortality were registered. Inappropriate antifungal treatment according to current Clinical & Laboratory Standards Institute (CLSI) breakpoints was adjusted with 30-day mortality-related co-variates.

RESULTS

One hundred forty-nine episodes of CBSI were analyzed. The most frequent species were: C. albicans (40%), C. tropicalis (23%) and C. glabrata complex (20%). According to the 2012 CLSI, 10.7% received inappropriate treatment. The 30-day mortality was 38%; severe sepsis [Odds ratio (OR) 3.4; 95% CI 1.3-8.4], cirrhosis (OR 36; 95% CI 12.2-605), early central venous catheter removal (OR 0.23; 95% CI 0.08-0.66) and previous antifungal therapy (OR 0.15; 95%CI 0.03-0.62), were associated with 30-day mortality by multivariate analysis. Inappropriate antifungal treatment was not (OR 0.19; 95% CI 0.03-1.2).

CONCLUSIONS

Appropriate antifungal therapy according to CLSI 2012 did not have an impact on mortality. Mortality of CBSI remains high due to disease severity and comorbidities; early antifungal therapy and catheter removal may reduce it.

Candidiasis and the impact of flow cytometry on antifungal drug discovery

INTRODUCTION

Invasive candidiasis continues to be associated with significant morbidity and mortality as well as substantial health care costs nationally and globally. One of the contributing factors is the development of resistance to antifungal agents that are already in clinical use. Moreover, there are known treatment limitations with all of the available antifungal agents. Since traditional techniques in novel drug discovery are time consuming, high-throughput screening using flow cytometry presents as a potential tool to identify new antifungal agents that would be useful in the management of these patients. Areas covered: In this review, the authors discuss the use of automated high-throughput screening assays based upon flow cytometry to identify potential antifungals from a library comprised of a large number of bioactive compounds. They also review studies that employed the use of this research methodology that has identified compounds with antifungal activity. Expert opinion: High-throughput screening using flow cytometry has substantially decreased the processing time necessary for screening thousands of compounds, and has helped enhance our understanding of fungal pathogenesis. Indeed, the authors see this technology as a powerful tool to help scientists identify new antifungal agents that can be added to the clinician's arsenal in their fight against invasive candidiasis.

The Surgical Infection Society Revised Guidelines on the Management of Intra-Abdominal Infection

BACKGROUND

Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations.

METHODS

Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council.

RESULTS

This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included.

SUMMARY

The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline.

Successful treatment of pulmonary candidiasis and aspergillosis in patient with refractory Hodgkin lymphoma using micafungin - case study and brief literature review

The number of patients with hematological malignancies who develop invasive fungal disease (IFD) has increased dramatically in recent decades. This increase is attributed to impairment of the host immune system due to intensive cytotoxic chemotherapies, use of corticosteroids and profound immunosuppression after hematopoietic stem cell transplantation (HSCT). Additionally, the increasing prevalence of fungal infections caused by emerging and rare pathogens, IFD of mixed etiology or of atypical localization is observed. There are also much more patients with IFD who do not belong to a well-described risk group, like patient with lymphoproliferative disorders. Within this heterogeneous group of patients, IFD epidemiology is not well defined and antifungal prophylaxis practices vary. The aim of this paper is to present the case of a 58-year-old patient with refractory Hodgkin disease, focusing on infectious complication after subsequent lines of chemotherapy. During deep and prolonged neutropaenia the patient developed symptoms of pneumonia. Despite antifungal prophylaxis with fluconazole, IFD of mixed etiology with the presence of Candida glabrata and Aspergillus fumigatus was diagnosed. The infection showed a poor response to monotherapy with liposomal amphotericin B, but was successfully treated with therapy involving micafungin. Analysis of the presented case demonstrated the necessity of new approaches to the prevention of IFD in patients with lymphoproliferative disorders heavily pretreated with numerous chemotherapy protocols. Prolonged neutropenia and high corticosteroid exposure put these patients in high risk of IFD like patients with acute myeloid leukemia/myelodysplastic syndrome or after allogeneic HSCT.

Azole Antifungal Resistance in Candida albicans and Emerging Non-albicans Candida Species

Within the limited antifungal armamentarium, the azole antifungals are the most frequent class used to treat Candida infections. Azole antifungals such as fluconazole are often preferred treatment for many Candida infections as they are inexpensive, exhibit limited toxicity, and are available for oral administration. There is, however, extensive documentation of intrinsic and developed resistance to azole antifungals among several Candida species. As the frequency of azole resistant Candida isolates in the clinical setting increases, it is essential to elucidate the mechanisms of such resistance in order to both preserve and improve upon the azole class of antifungals for the treatment of Candida infections. This review examines azole resistance in infections caused by C. albicans as well as the emerging non-albicans Candida species C. parapsilosis, C. tropicalis, C. krusei, and C. glabrata and in particular, describes the current understanding of molecular basis of azole resistance in these fungal species.

Antifungal susceptibility of Candida species isolated from patients with candidemia in southern Taiwan, 2007-2012: impact of new antifungal breakpoints

The Clinical and Laboratory Standard Institute (CLSI) revised the clinical breakpoints (CBPs) for the azoles and echinocandins against Candida species in 2012. We aimed to report the epidemiology of candidemia and antifungal susceptibility of Candida species and evaluate the impact of new CBPs on antifungal susceptibility in our region. All blood isolates of Candida species were obtained from 2007 to 2012. The minimum inhibitory concentrations of fluconazole, voriconazole, echinocandins and flucytosine against Candida isolates were determined by Sensititre YeastOne system. Differences in susceptibility rates between the CBPs of previous and revised versions of CLSI were examined. Of 709 Candida isolates, the fluconazole-susceptible rate was 96.5% in Candida albicans, 85.8% in Candida tropicalis and 92.1% in Candida parapsilosis by the revised CBPs. Compared with the susceptibility results by previous CBPs, the marked reductions in susceptibility of C. albicans, C. tropicalis and C. parapsilosis to fluconazole, that of C. tropicalis and C. parapsilosis to voriconazole, that of C. tropicalis and Candida glabrata to anidulafungin and that of C. tropicalis, C. glabrata and Candida krusei to caspofungin by revised CBPs were found. In conclusion, Candida albicans and C. parapsilosis remain highly susceptible to fluconazole. The non-susceptible rates of Candida species to azoles and echinocandins increase with interpretation by the revised CBPs.