Risk factors and outcomes of candidemia caused by Candida parapsilosis complex in a medical center in northern Taiwan

Candida parapsilosis: A systematic review to inform the World Health Organization fungal priority pathogens list

Candida parapsilosis is globally distributed and recognised for causing an increasing proportion of invasive Candida infections. It is associated with high crude mortality in all age groups. It has been particularly associated with nosocomial outbreaks, particularly in association with the use of invasive medical devices such as central venous catheters. Candida parapsilosis is one of the pathogens considered in the WHO priority pathogens list, and this review was conducted to inform the ranking of the pathogen in the list. In this systematic review, we searched PubMed and Web of Science to find studies between 2011 and 2021 reporting on the following criteria for C. parapsilosis infections: mortality, morbidity (hospitalisation and disability), drug resistance, preventability, yearly incidence, and distribution/emergence. We identified 336 potentially relevant papers, of which 51 were included in the analyses. The included studies confirmed high mortality rates, ranging from 17.5% to 46.8%. Data on disability and sequelae were sparse. Many reports highlighted concerns with azole resistance, with resistance rates of >10% described in some regions. Annual incidence rates were relatively poorly described, although there was clear evidence that the proportion of candidaemia cases caused by C. parapsilosis increased over time. While this review summarises current data on C.parapsilosis, there remains an urgent need for ongoing research and surveillance to fully understand and manage this increasingly important pathogen.

Candida albicans-A systematic review to inform the World Health Organization Fungal Priority Pathogens List

Candida albicans is a common fungal pathogen and amongst the leading causes of invasive candidiasis globally. This systematic review examines the characteristics and global impact of invasive infections caused by C. albicans. We searched on PubMed and Web of Science for studies reporting on criteria such as mortality, morbidity, drug resistance, preventability, yearly incidence, and distribution/emergence during the period from 2016 to 2021. Our findings indicate that C. albicans is the most common Candida species causing invasive disease and that standard infection control measures are the primary means of prevention. However, we found high rates of mortality associated with infections caused by C. albicans. Furthermore, there is a lack of data on complications and sequelae. Resistance to commonly used antifungals remains rare. Although, whilst generally susceptible to azoles, we found some evidence of increasing resistance, particularly in middle-income settings-notably, data from low-income settings were limited. Candida albicans remains susceptible to echinocandins, amphotericin B, and flucytosine. We observed evidence of a decreasing proportion of infections caused by C. albicans relative to other Candida species, although detailed epidemiological studies are needed to confirm this trend. More robust data on attributable mortality, complications, and sequelae are needed to understand the full extent of the impact of invasive C. albicans infections.

Invasive Candida parapsilosis Bloodstream Infections in Children: The Antifungal Susceptibility, Clinical Characteristics and Impacts on Outcomes

Background: Candida parapsilosis is the most common non-albicans candida species that causes invasive candidiasis, but little is known about its impacts on the outcomes of pediatric patients. We aimed to characterize the clinical characteristics, risk factors and outcomes of C. parapsilosis bloodstream infections (BSIs) in children. Methods: All pediatric patients with Candida parapsilosis BSIs between 2005 and 2020 from a medical center in Taiwan were enrolled and analyzed. The antifungal susceptibility, clinical manifestations, management and outcomes were investigated. Cases of Candida parapsilosis BSIs were compared between patients with C. albicans BSIs and other Candida spp. BSIs. Results: During the study period, 95 episodes (26.0% of total cases) of Candida parapsilosis BSIs were identified and analyzed. No significant difference was found between pediatric patients with C. parapsilosis BSIs and those with C. albicans BSIs in terms of patients' demographics, most chronic comorbidities or risk factors. Pediatric patients with C. parapsilosis BSIs were significantly more likely to have previous azole exposure and be on total parenteral nutrition than those with C. albicans BSIs (17.9 vs. 7.6% and 76.8 vs. 63.7%, p = 0.015 and 0.029, respectively). The duration of C. parapsilosis candidemia was relatively longer, and therefore patients often required a longer duration of antifungal treatment when compared with those of C. albicans candidemia, although the candidemia-attributable mortality rates were comparable. Of the C. parapsilosis isolates, 93.7% were susceptible to all antifungal agents, and delayed appropriate antifungal treatment was an independent factor in treatment failure. Conclusions: Pediatric patients with C. parapsilosis BSIs were more likely to have previous azole exposure and be on total parenteral nutrition, and the clinical significances included a longer duration of candidemia and patients often required a longer duration of antifungal treatment.

Synthesis, Characterization, DFT Study and Antifungal Activities of Some Novel 2-(Phenyldiazenyl)phenol Based Azo Dyes

In recent decades, there has been an increased interest in azo compounds with special optical and biological properties. In this work, we report the preparation of novel azo-compounds with two and three -N=N- double bonds, using the classical method of synthesis, diazotization and coupling. The compounds were characterized by ¹H-NMR, ¹³C-NMR, FTIR, UV-VIS and fluorescence spectra. DFT calculations were employed for determining the optical parameters, polarizability α, the total static dipole moment μ_tot, the quadrupole moment Q and the mean first polarizability β_tot. All azo derivatives show strong fluorescence emission in solutions. The antioxidant and antifungal activities were determined and the influence of the number of azo bonds was discussed. The synthesized compounds exhibit remarkable efficiency in the growth reduction of standard and clinical isolated Candida strains, suggesting future applications as novel antifungal.

Enhanced Virulence of Candida albicans by Staphylococcus aureus: Evidence in Clinical Bloodstream Infections and Infected Zebrafish Embryos

Coinfection with Candida and Staphylococcus results in higher mortality in animal studies. However, the pathogenesis and interplay between C. albicans and S. aureus in bloodstream infections (BSIs) is unclear. This study determines the clinical features and outcomes of mixed C. albicans/S. aureus (CA/SA) BSIs and biofilm formation on pathogenesis during coinfection. Demographics and outcomes for mixed BSIs and monomicrobial candidemia were compared. Compared to 115 monomicrobial C. albicans BSIs, 22 patients with mixed CA/SA BSIs exhibited a significantly higher mortality rate and shorter survival time. In vitro and in vivo biofilm analysis showed that C. albicans accounted for the main biofilm architecture, and S. aureus increased its amount. Antibiotic tolerance in S. aureus, which adhered to Candida hyphae observed by scanning electron microscope, was demonstrated by the presence of wild-type C. albicans co-biofilm. Upregulation in exotoxin genes of S. aureus was evidenced by quantitative RT-PCR when a co-biofilm was formed with C. albicans. Mixed CA/SA BSIs result in a higher mortality rate in patients and in vivo surrogate models experiments. This study demonstrates that the virulence enhancement of C. albicans and S. aureus during co-biofilm formation contributes to the high mortality rate.

Hospital outbreak of fluconazole-resistant Candida parapsilosis: arguments for clonal transmission and long-term persistence

The worldwide emergence of multidrug-resistant pathogenic fungi is a threat to human health. At this very moment, an emergence of Candida parapsilosis isolates harbouring a resistance to fluconazole, one of the most popular antifungal drugs, is being described in several countries. We seek to better understanding the epidemiology, pathogenicity and transmission of resistant Candida parapsilosis Faced with an outbreak of invasive infections due to resistant isolates of C. parapsilosis, we performed a 7-year retrospective and prospective analysis of 283 C. parapsilosis isolates collected in 240 patients, among who 111 had invasive candidiasis. Study included review of hospital records, genotyping analysis and susceptibility testing that allow determining the type and outcome of infections, as well as the spatial and temporal spread of clusters. Overall the incidence of azole resistance was 7.5%. Genotyping analysis unveiled several previously undetected outbreaks and clonal spread of susceptible and resistant isolates over a long period of time. In comparison with susceptible isolates, resistant ones have a more restricted genetic diversity and seem to be more likely to spread and more frequently associated with invasive infections. In intensive care units, patients with invasive infections due to resistant isolates had poorer outcome (overall mortality at day 30 of 40%; 4/10) than susceptible ones (overall mortality at day 30 of 26.5%; 9/34). Our results suggest that the propensity of C. parapsilosis to spread on an epidemic fashion is underestimated, which warrants reinforced control and epidemiological survey of this species.

Accuracy of matrix-assisted LASER desorption ionization-time of flight mass spectrometry for identification of Candida

Background: Candida is a fungus that causes various types of candidemia, which is the fourth major infectious disease of the blood system. MALDI-TOF-MS is a simple and rapid detection instrument. The aim of the present study was to verify the accuracy of MALDI-TOF-MS in detecting Candida.

Method: A pooled analysis of articles on MALDI-TOF-MS for diagnosis of candidemia was performed. The quality of original research was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) guidelines. Stata 12.0 software was used to merge the correct identification rates of Candida and Candida subspecies and obtain pooled sensitivity and specificity of the diagnostic methods. Heterogeneity was found in the subgroup analysis of the included articles. Hence, we explored the factors causing the heterogeneity and its impact on the overall situation. Sensitivity analysis was used to examine the effect of Candida level on total response. Egger’s test was used to evaluate the publication bias of the included articles.

Results: A total of 16 articles in Pubmed, 79 articles in Embase, 1 article in Cochrane Library, 30 articles in Web of Science and 3 from other sources were identified, of which 10 articles were included based on the inclusion and exclusion criteria. The overall identification accuracy was 100%.

Conclusion: The accuracy of MALDI-TOF-MS for the identification of Candida was 100%. Further research is necessary to determine whether MALDI-TOF-MS can be used as a clinical diagnostic standard for the identification of Candida.

Mortality and risk factor analysis for Candida blood stream infection: A three-year retrospective study

BACKGROUND

The aim of this study was to evaluate the possible risk factors for mortality in adult patients with candidemia by investigating the causative agents, underlying conditions and predisposing factors.

MATERIAL AND METHODS

The data including causative Candida species, predisposing factors, and underlying conditions of candidemia patients between the years 2015-2017 were collected and the impact of these factors on mortality was evaluated. Patients were divided into two groups as died (died patients within 30 days of the onset of candidemia) and survived and risk factors were evaluated for each group.

RESULTS

We found 163 adult candidemia cases during the study period. Overall 30-day mortality was 40.5%. Candida parapsilosis was the most frequent causative agent (49.1%). C. parapsilosis candidemia was more common in the survived group compared with the died group (n: 49 (61.3%) vs. n: 31 (38.8%), P=0.888). Mortality rates were significantly higher in patients with dialysis (n: 27 (69.2%) vs. n: 12 (30.8%), P<0.00) and concurrent bacteremia (n: 20 (57.1%) vs. n: 15 (42.9%), P=0.024). Survival rates were significantly higher in patients with follow-up blood cultures (n: 75 (65.8%) vs. n: 39 (34.2%), P=0.013). The most important source of candidemia was catheter (49.7%), and C. parapsilosis was the most common causative agent (58%). The catheter was removed in 96.3% of these patients and the mortality rate was 38.5%. All of the patients received antifungal therapy and there was no significant difference between the effects of antifungals on mortality (n: 65 (39.9%) vs. 98 (60.1%), P=0.607).

CONCLUSIONS

Dialysis and concurrent bacteremia are strong predictors of mortality in 30 days within patients with candidemia, whereas follow-up blood cultures have a protective role with lower mortality rates. In our study, the most important source of candidemia was catheter, and C. parapsilosis was the most common causative agent. The catheter was removed in almost all patients and the mortality rate was almost one third among these patients.

Clinical Usefulness of Susceptibility Breakpoints for Yeasts in the Treatment of Candidemia: A Noninterventional Study

This prospective noninterventional study evaluated whether antifungal susceptibility data (MIC) provided for Candida clinical isolates on the basis of recently established breakpoints are taken into account by clinicians to guide their treatment decision making process, and assessed the response in MIC- and non-MIC-based treatment groups. During a six month period, the usage of systemic antifungals was recorded in detail and compared with mycological data (Candida species and MICs) in candidemia patients. Patients were assigned to a susceptible or resistant infection group based on European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints; treatment decisions were under the professional discretion of the treating physicians. 123 patients were evaluated with Candida albicans accounting for 59%, Candida glabrata for 19%, Candida parapsilosis for 15%, Candida tropicalis for 4% and Candida krusei for 3%. Antifungal treatment correlated with species and MICs in 80% (n = 99 patients), high MICs and species-dependent guideline recommendations were ignored in 20% (n = 24 patients); the overall outcome of candidemia cases in our study population was excellent, as by day 14, all patients were cleared from fungal blood stream infection (mean 5.6 days, range 2–12). The current variability in antifungal usage and the delay in initiating appropriate therapy indicate a need for antifungal stewardship to improve the management of invasive fungal infections.

Evaluating glucose and mannose profiles in Candida species using quantum dots conjugated with Cramoll lectin as fluorescent nanoprobes

Glycoconjugates found on cell walls of Candida species are fundamental for their pathogenicity. Laborious techniques have been employed to investigate the sugar composition of these microorganisms. Herein, we prepared a nanotool, based on the fluorescence of quantum dots (QDs) combined with the specificity of Cramoll lectin, to evaluate glucose/mannose profiles on three Candida species. The QDs-Cramoll conjugates presented specificity and bright fluorescence emission. The lectin preserved its biological activity after the conjugation process mediated by adsorption interactions. The labeling of Candida species was analyzed by fluorescence microscopy and quantified by flow cytometry. Morphological analyses of yeasts labeled with QDs-Cramoll conjugates indicated that C. glabrata (2.7 μm) was smaller when compared to C. albicans (4.0 μm) and C. parapsilosis sensu stricto (3.8 μm). Also, C. parapsilosis population was heterogeneous, presenting rod-shaped blastoconidia. More than 90% of cells of the three species were labeled by conjugates. Inhibition and saturation assays indicated that C. parapsilosis had a higher content of exposed glucose/mannose than the other two species. Therefore, QDs-Cramoll conjugates demonstrated to be effective fluorescent nanoprobes for evaluation of glucose/mannose constitution on the cell walls of fungal species frequently involved in candidiasis.