Invasive Fungal Infection in Romania: Changing Incidence and Epidemiology During Six Years of Surveillance in a Tertiary Hospital

Epidemiology and Antifungal Susceptibility Patterns of Invasive Fungal Infections (IFIs) in India: A Prospective Observational Study

The epidemiology of invasive fungal infections (IFI) is ever evolving. The aim of the present study was to analyze the clinical, microbiological, susceptibility, and outcome data of IFI in Indian patients to identify determinants of infection and 30-day mortality. Proven and probable/putative IFI (defined according to modified European Organization for Research and Treatment of Cancer/Mycoses Study Group and AspICU criteria) from April 2017 to December 2018 were evaluated in a prospective observational study. All recruited patients were antifungal naïve (n = 3300). There were 253 episodes of IFI (7.6%) with 134 (52.9%) proven and 119 (47%) probable/putative infections. There were four major clusters of infection: invasive candidiasis (IC) (n = 53, 20.9%), cryptococcosis (n = 34, 13.4%), invasive aspergillosis (IA) (n = 103, 40.7%), and mucormycosis (n = 62, 24.5%). The significant risk factors were high particulate efficiency air (HEPA) room admission, ICU admission, prolonged exposure to corticosteroids, diabetes mellitus, chronic liver disease (CLD), acquired immunodeficiency syndrome (AIDS), coronary arterial disease (CAD), trauma, and multiorgan involvement (p < 0.5; odds ratio: >1). The all-cause 30-day mortality was 43.4% (n = 110). It varied by fungal group: 52.8% (28/53) in IC, 58.8% (20/34) in cryptococcosis, 39.8% (41/103) in IA, and 33.9% (21/62) in mucormycosis. HEPA room, ICU admission for IC; HEPA rooms, diabetes mellitus for cryptococcosis; hematological malignancies, chronic kidney disease (CKD), sepsis, galactomannan antigen index value ≥1 for IA and nodules; and ground glass opacities on radiology for mucormycosis were significant predictors of death (odds ratio >1). High minimum inhibitory concentration (MIC) values for azoles were observed in C. albicans, C. parapsilosis, C. glabrata, A. fumigatus, A. flavus, R. arrhizus, R. microsporus, and M. circinelloides. For echinocandin, high MIC values were seen in C. tropicalis, C. guillermondii, C. glabrata, and A. fumigatus. This study highlights the shift in epidemiology and also raises concern of high MICs to azoles among our isolates. It warrants regular surveillance, which can provide the local clinically correlated microbiological data to clinicians and which might aid in guiding patient treatment.

Inhibition of Phospholipase by Orlistat as an Alternate Therapy to Combat Opportunistic Mycosis Caused by C. albicans

Candida albicans is one of the most important etiological agents causing an opportunistic mycosis, candidiasis. In the past, it was perceived to be associated with immunocompromised patients only. However, it has now been reported with several clinical complications with varying severity. Additionally, increasing incidences of multiple drug resistance associated with the infections have complicated its treatment as well. Therefore, an investigation of alternate therapy, for instance, inhibition of the virulence factors is desperately needed. In the present study, a multidrug-resistant Candida albicans SDL-4 was screened for secretion of the virulence factors: aspartyl proteases and phospholipases. The pathogen secreted phospholipases potentially compared to aspartyl proteases. Therefore, C. albicans SDL-4 phospholipase was purified to homogeneity, characterized, and its inhibition was studied subsequently. It catalysed the substrate, p-nitrophenyl palmitate, optimally in 0.1 M acetate buffer, pH 5, at 37 °C. In the present study, we also aimed to re-purpose orlistat, which is a commercially available anti-obesity drug. Orlistat, at the concentration of 360 μg/ml, could diminish the activity and stability of the candidal virulence factor. Its half-life was reduced in the presence of orlistat at 37 °C. As well, increase in K_m and unaltered V_max indicated that orlistat inhibited phospholipase competitively. The inhibition kinetics was supported by measuring alterations in the secondary structure of the candidal phospholipase upon treatment with orlistat by the circular dichroism spectroscopy and K2D3. Moreover, validation of the study at clinical level may establish orlistat as a supportive treatment to reduce invasiveness and related medical intricacies during candidiasis.

Characterization of the transcriptional response of Candida parapsilosis to the antifungal peptide MAF-1A

Candida parapsilosis is a major fungal pathogen that leads to sepsis. New and more effective antifungal agents are required due to the emergence of resistant fungal strains. MAF-1A is a cationic antifungal peptide isolated from Musca domestica that is effective against a variety of Candida species. However, the mechanism(s) of its antifungal activity remains undefined. Here, we used RNA-seq to identify differentially expressed genes (DEGs) in Candida parapsilosis following MAF-1A exposure. The early (6 h) response included 1,122 upregulated and 1,065 downregulated genes. Late (18 h) responses were associated with the increased expression of 101 genes and the decreased expression of 151 genes. Upon MAF-1A treatment for 18 h, 42 genes were upregulated and 25 genes were downregulated. KEGG enrichment showed that the DEGs in response to MAF-1A were mainly involved in amino acid synthesis and metabolism, oxidative phosphorylation, sterol synthesis, and apoptosis. These results indicate that MAF-1A exerts antifungal activity through interference with Candida parapsilosis cell membrane integrity and organelle function. This provides new insight into the interaction between Candida parapsilosis and this antimicrobial peptide and serves as a reference for future Candida parapsilosis therapies.

Mixed fungaemia: an 18-year report from a tertiary-care university hospital and a systematic review

BACKGROUND

While fungaemia caused by two or more different species of yeasts (mixed fungaemia, MF) is infrequent, it might be underestimated.

AIMS

This study aimed to determine the incidence of MF, clinical characteristics of the patients, and antifungal susceptibility profiles of the isolates with a systematic review of the literature.

SOURCES

Data sources were PubMed and Scopus.

STUDY ELIGIBILITY CRITERIA

Studies reporting ten or more mixed fungaemia episodes.

CONTENT

Study included MF episodes in adults between January 2000 and August 2018 in Hacettepe University Hospitals, Turkey. The isolation, identification and antifungal susceptibility testing (AFST) of the isolates were by standard mycological methods. Patient data were obtained retrospectively. Literature search was performed using relevant keywords according to PRISMA systematic review guidelines. A total of 32 patients with 33 MF episodes were identified. Among all fungaemia episodes, MF incidence was 3.7% (33/883). All patients had one or more underlying disorders among which solid-organ cancer (50.0%, 16/32) was the most common. Overall mortality was 51.5% (17/33). The most preferred antifungal agents for initial treatment were fluconazole (48.5%, 16/33) and echinocandins (39.4%, 13/33). Fluconazole susceptible-dose-dependent (S-DD) or -resistant Candida species were detected in 15 episodes, and an isolate of C. parapsilosis was classified as S-DD by AFST. All Candida isolates were susceptible to echinocandins. Non-candida yeasts with intrinsic resistance/reduced susceptibility to both echinocandins and fluconazole were detected in two episodes. Systematic review of the literature revealed 24 studies that reported more than ten MF episodes. Methodology was variable. Improvement of detection rates was reported when chromogenic agars were used. Most studies underlined detection of isolates with reduced susceptibility.

IMPLICATIONS

Although rare, the MF rate is affected by the detection methods, which have improved in recent years. Fluconazole and echinocandins were used for initial treatment in accordance with the current guideline recommendations; however, isolates non-susceptible to both were detected. Detection of a mixed infection offers an opportunity for optimum treatment.

In Vitro Interaction of Geldanamycin with Triazoles and Echinocandins Against Common and Emerging Candida Species

The aim of this study was to determine the in vitro interactions of geldanamycin (Hsp90-inhibitor) with triazoles and echinocandins against common and emerging Candida species. Twenty clinically important Candida strains comprising C. auris, C. albicans, C. parapsilosis, and C. glabrata (each five strains) were included. In vitro interactions of geldanamycin with fluconazole, itraconazole, caspofungin and anidulafungin were determined using a checkerboard method. The results were interpreted as synergistic, indifferent and antagonistic based on the fractional inhibitory concentration index (FICI). In vitro combination of fluconazole with geldanamycin resulted in synergistic effect against C. albicans (100%), C. glabrata (80%) and C. parapsilosis (80%) (FICI range 0.009-0.5), while indifferent interactions were obtained against C. auris (FICI range 1.5-2). The overall minimum inhibitory concentration (MIC) range of fluconazole against C. albicans, C. glabrata and C. parapsilosis reduced from 16-256 to 0.25-64 mg/L when combined with geldanamycin. Regarding the synergistic effect of geldanamycin with itraconazole against all strains of C. albicans, C. glabrata and C. parapsilosis (FICI range 0.009-0.375), the MIC range of this antifungal was reduced from 0.125-32 mg/L when tested alone, to 0.03-1 mg/L. Combinations of geldanamycin with fluconazole and itraconazole against C. auris, as well as combination of geldanamycin with caspofungin and anidulafungin against all studied Candida species, resulted in indifferent effects. No antagonism was observed. Simultaneous targeting of Hsp90 and lanosterol 14-α demethylase seems an effective approach against C. albicans, C. glabrata and C. parapsilosis. However, this combination is ineffective against the emerging pathogen C. auris.

Epidemiology of candiduria and Candida urinary tract infections in inpatients and outpatients: results from a 10-year retrospective survey

Introduction

The presence of Candida species in urine (candiduria) is a common clinical finding, which may frequently represent colonization or contamination of specimens, however, they may be etiological agents in urinary tract infections (UTIs) or be indicators of underlying pathology in the genitourinary system or disseminated candidaemia. C. albicans is the most frequently isolated species of the genus, however, an increase in the occurrence of non-albicans Candida species (NACS) has been reported, which may be attributable to frequent exposure to fluconazole.

Material and methods

The aim of this study was to retrospectively assess and compare the prevalence of candiduria and UTIs caused by Candida spp. among inpatients and outpatients at a major clinical center in Hungary, during a 10-year period (2008-2017).

Results

Candiduria was detected in 0.11-0.75% of positive samples from outpatients, while this number was significantly higher for inpatients, ranging between 3.49-10.63% (p <0.001). Overall, C. albicans was the most frequently isolated species (65.22% in outpatients and 59.64% in inpatients), however, the presence of C. glabrata as a relevant etiologic agent (~20-30%) is also noteworthy, because there are corresponding therapeutic consequences.

Conclusions

A pronounced female dominance (1.7-2.15-fold), advanced age (~70 years) and hospitalization of affected patients during candiduria is in line with the findings in literature.