International surveillance of bloodstream infections due to Candida species: frequency of occurrence and in vitro susceptibilities to fluconazole, ravuconazole, and voriconazole of isolates collected from 1997 through 1999 in the SENTRY antimicrobial surveillance program

Ningalins, Pyrrole-Bearing Metabolites Isolated from Didemnum spp. Synthesis and MDR-Reversion Activity in Cancer Therapy

Multi-Drug Resistance (MDR) is one of the most frequent problems observed in the course of cancer chemotherapy. Cells under treatment, tend to develop survival mechanisms to drug-action thus generating drug-resistance. One of the most important mechanism to get it is the over expression of P-gp glycoprotein, which acts as an efflux-pump releasing the drug outside of the cancer cell. A strategy for a succesfull treatment consists in the co-administration of one compound that acts against P-gp and another which acts against the cell during chemotherapy. Ningalins are pyrrole-containing naturally occurring compounds isolated mainly from the marine tunicate Didemnum spp and also they are some of the top reversing agents in MDR treatment acting on P-gp. Considering the relevance displayed for some of these isolated alkaloids or their core as a drug for co-administration in cancer therapy, all the total synthesis described to date for the members of ningalins family are reviewed herein.

Inhibitors of 3-Hydroxy-3-methylglutaryl Coenzyme A Reductase Decrease the Growth, Ergosterol Synthesis and Generation of petite Mutants in Candida glabrata and Candida albicans

Candida glabrata and Candida albicans, the most frequently isolated candidiasis species in the world, have developed mechanisms of resistance to treatment with azoles. Among the clinically used antifungal drugs are statins and other compounds that inhibit 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), resulting in decreased growth and ergosterol levels in yeasts. Ergosterol is a key element for the formation of the yeast cell membrane. However, statins often cause DNA damage to yeast cells, facilitating mutation and drug resistance. The aim of the current contribution was to synthesize seven series of compounds as inhibitors of the HMGR enzyme of Candida ssp., and to evaluate their effect on cellular growth, ergosterol synthesis and generation of petite mutants of C. glabrata and C. albicans. Compared to the reference drugs (fluconazole and simvastatin), some HMGR inhibitors caused lower growth and ergosterol synthesis in the yeast species and generated fewer petite mutants. Moreover, heterologous expression was achieved in Pichia pastoris, and compounds 1a, 1b, 6g and 7a inhibited the activity of recombinant CgHMGR and showed better binding energy values than for α-asarone and simvastatin. Thus, we believe these are good candidates for future antifungal drug development.

Fermented fish and fermented fish-based products, an ever-growing source of microbial diversity: A literature review

Fermented fish and fermented fish-based products are part of the diet of many countries all over the world. Their popularity is not only due to the unique flavor, the distinct texture, and the good nutritional quality, but also to the easiness of the production process, that is commonly based on empirical traditional methods. Fish fermentation techniques ususally rely on the combination of some key steps, including salting, addition of spices or additives, and maintenance of anaerobic conditions, thus selecting for the multiplication of some pro-technological microorganisms. The objective of the present review was to provide an overview of the current knowledge of the microbial communities occurring in fermented fish and fish-based products. Specific information was collected from scientific publications published from 2000 to 2022 with the aim of generating a comprehensive database. The production of fermented fish and fish-based foods was mostly localized in West African countries, Northern European countries, and Southeast Asian countries. Based on the available literature, the microbial composition of fermented fish and fish-based products was delineated by using viable counting combined with identification of isolates, and culture-independent techniques. The data obtained from viable counting highlighted the occurrence of microbial groups usually associated with food fermentation, namely lactic acid bacteria, staphylococci, Bacillus spp., and yeasts. The identification of isolates combined with culture-independent methods showed that the fermentative process of fish-based products was generally guided by lactobacilli (Lactiplantibacillus plantarum, Latilactobacillus sakei, and Latilactobacillus curvatus) or Tetragenococcus spp. depending on the salt concentration. Among lactic acid bacteria populations, Lactococcus spp., Pediococcus spp., Leuconostoc spp., Weissella spp., Enterococcus spp., Streptococcus spp., and Vagococcus spp. were frequently identified. Staphylococcus spp. and Bacillus spp. confirmed a great adaptation to fermented fish-based products. Other noteworthy bacterial taxa included Micrococcus spp., Pseudomonas spp., Psychrobacter spp., Halanaerobium spp., and Halomonas spp. Among human pathogenic bacteria, the occurrence of Clostridium spp. and Vibrio spp. was documented. As for yeast populations, the predominance of Candida spp., Debaryomyces spp., and Saccharomyces spp. was evidenced. The present literature review could serve as comprehensive database for the scientific community, and as a reference for the food industry in order to formulate tailored starter or adjunctive cultures for product improvement.

Fluconazole and echinocandin resistance of Candida species in invasive candidiasis at a university hospital during pre-COVID-19 and the COVID-19 outbreak

Antifungal susceptibility of Candida species is decreasing. Successful treatment for antifungal-resistant candida infection is challenging and associated with significant mortality. We performed a prospective observational study to identify the species and antifungal susceptibilities of invasive isolates of Candida species over a 5-year period at a university hospital in southern Thailand. Between 2017 and 2021, the species distribution was 39.1% Candida tropicalis, 24.8% Candida albicans, 20.3% Candida parapsilosis complex, 10.5% Candida glabrata, and 5.2% miscellaneous Candida spp. Notable observations include elevated minimal inhibitory concentration (MIC) and decrease susceptibility of C. tropicalis and C. glabrata to echinocandin and all tested triazoles. A shift of MIC90 value in the COVID-19 era was seen in C. albicans and C. tropicalis with azoles and echinocandins. Azole resistance increased among C. tropicalis isolates, and echinocandin resistance also increased among C. parapsilosis and C. glabrata isolates. Novel alterations in FKS1 HS1 and HS2 were detected in both isolates of anidulafungin-resistant C. parapsilosis. As Candida species have become more resistant to azoles and less susceptible to echinocandin development, the need arose to observe the emergence of resistance to both antifungal classes in candida clinical isolates, for a more effective infection control in the hospital.

Clinical and Microbiological Characteristics of Candidemia Cases in Saudi Arabia

Purpose

Candidemia and antifungal resistance are major healthcare challenges. The aim of this study is to describe the frequency of candidemia cases, distribution of Candida spp., and the associated risk factors for mortality in an academic institution in Saudi Arabia over an 18-month period. We also evaluated the susceptibility patterns of Candida blood isolates.

Methods

Candidemia cases were collected from King Fahad Hospital of the University over the period between July 1st, 2020 through December 31st, 2021. They were prospectively reviewed for the preceding risk factors and antifungal (AF) susceptibility, testing results to fluconazole (FL), voriconazole (VO), itraconazole (IT), posaconazole (PO), caspofungin (CASP), anidulafungin (AND), micafungin (MYC), flucytosine (FLC) and amphotericin B (AMPB) using a broth microdilution kit (Sensititre™ YeastOne).

Results

A total of 48 candidemia isolates were included that were isolated from 43 patients. The median age of cases was 62 ± 23.3 years (60.4% males and 83% ICU patients). Independent risk factors for mortality at 30 days in candidemia patients were age, COVID-19 co-infection, and use of tocilizumab. The most commonly isolated species were C. glabrata and C. parapsilosis (22.9% each) followed by C. albicans (18.75%). AF resistance for ≥1 antifungal was detected in 39.3% of 33 cases tested, with no cross-resistance identified. Resistance rates for each AF were as follows: FL (18%), VO (6%), IT (6%), PO (9%) and AMPB (3%). No resistance was seen for echinocandins apart from one C. krusei strain showing an intermediate result for CASP.

Conclusion

The study showed an overall high rate of non-albicans Candida, with the predominance of C. parapsilosis and C. glabrata, representing a therapeutic challenge. AF resistance rate was high which emphasizes the importance of continuing surveillance and providing accurate and reliable tools in the laboratories for rapid speciation and susceptibility testing.

Rapid Identification of Pathogens Causing Bloodstream Infections by Raman Spectroscopy and Raman Tweezers

The search for the "Holy Grail" in clinical diagnostic microbiology-a reliable, accurate, low-cost, real-time, easy-to-use method-has brought up several methods with the potential to meet these criteria. One is Raman spectroscopy, an optical, nondestructive method based on the inelastic scattering of monochromatic light. The current study focuses on the possible use of Raman spectroscopy for identifying microbes causing severe, often life-threatening bloodstream infections. We included 305 microbial strains of 28 species acting as causative agents of bloodstream infections. Raman spectroscopy identified the strains from grown colonies, with 2.8% and 7% incorrectly identified strains using the support vector machine algorithm based on centered and uncentred principal-component analyses, respectively. We combined Raman spectroscopy with optical tweezers to speed up the process and captured and analyzed microbes directly from spiked human serum. The pilot study suggests that it is possible to capture individual microbial cells from human serum and characterize them by Raman spectroscopy with notable differences among different species. IMPORTANCE Bloodstream infections are among the most common causes of hospitalizations and are often life-threatening. To establish an effective therapy for a patient, the timely identification of the causative agent and characterization of its antimicrobial susceptibility and resistance profiles are essential. Therefore, our multidisciplinary team of microbiologists and physicists presents a method that reliably, rapidly, and inexpensively identifies pathogens causing bloodstream infections-Raman spectroscopy. We believe that it might become a valuable diagnostic tool in the future. Combined with optical trapping, it offers a new approach where the microorganisms are individually trapped in a noncontact way by optical tweezers and investigated by Raman spectroscopy directly in a liquid sample. Together with the automatic processing of measured Raman spectra and comparison with a database of microorganisms, it makes the whole identification process almost real time.

Increased prevalence of fungemia in Medina, Saudi Arabia

Background

The prevalence of fungal infection is increasing globally due to an increase in the immunocompromised and aging population. We investigated epidemiological changes in fungemia in one of the major centers in Medina over seven years period with 87,447 admissions.

Methods

Retrospective search of records for causative agents of fungemia in inpatients at King Fahad Hospital (KFH) in 2013-2019. Fungal-positive blood cultures, demographic, and treatment data were extracted.

Results

A total of 331 fungemia episodes proven by blood culture were identified in 46 patients. The annual prevalence of fungemia increased from 0.072 in 2013 to 1.546 patients per 1,000 in 2019. The mean age of fungemia episodes was 56 years, and 62% of episodes occurred in females. Samples from central blood incubated aerobically yielded the highest fungemia rate, accounting for 55% (n = 182). Among yeast species, Candida parapsilosis was responsible for the highest number of episodes 37% (n = 122), followed by Candida glabrata (32%; n = 107), Candid albicans (29%; n = 94), and Cryptococcus neoformans (1%; n = 4). Among molds, Lichtheimia (Absidia) species was the most common (1%; n = 3). Yeast-like fungi Trichosporion mucoides accounted for (0.003% n = 1). The use of antifungal treatment has increased (96%) over the years (2013-2019). An increase in resistance rate of 2% was found in C. albicans and C. glabrata. The most prevalent comorbidity was renal disease (24.2%).

Conclusions

C. parapsilosis was the leading cause of fungemia. The association of renal disease with increased candidemia was alarming. This study is a fundamental resource to establish management policies for fungal infection in the region.

Incidence, susceptibility and outcomes of candidemia in adults living in Calgary, Alberta, Canada (2010-2018)

BACKGROUND

Candidemia is increasing in frequency and is associated with high mortality. We sought to determine the burden of illness, the population it affects and its resistance profile in our region.

METHODS

The Calgary Zone (CZ) provides all care for residents of Calgary and surrounding communities (~ 1.69 million) via five tertiary hospitals each served by a common single laboratory for acute care microbiology. All adult patients in the CZ with at least one Candida spp.-positive blood culture between January 1, 2010, and December 31, 2018, were identified using microbiological data from Calgary Lab Services, the laboratory that processes > 95% of all blood culture samples in the CZ, were reviewed for the study.

RESULTS

The overall annual incidence of candidemia among individuals living in the CZ was 3.8 per 100,000 persons (Median age 61 years (IQR 48-72) and 221/455 (47.4%) were female). C. albicans was the most common species (50.6%), followed by C. glabrata, (24.0%). No other species accounted for more than 7% of cases. Overall mortality at 30, 90, and 365 days was 32.2, 40.1, and 48.1% respectively. Mortality rate did not differ by Candida species. Of individuals who developed candidemia, more than 50% died within the next year. No new resistance pattern has emerged in the most common Candida species in Calgary, Alberta.

CONCLUSIONS

In Calgary, Alberta, the incidence of candidemia has not increased in the last decade. C. albicans was the most common species and it remains susceptible to fluconazole.

Early Empirical Anidulafungin Reduces the Prevalence of Invasive Candidiasis in Critically Ill Patients: A Case-control Study

Introduction

Invasive candidiasis (IC) in critically ill patients is a serious infection with high rate of mortality. As an empirical therapy, like antibiotics, the use of antifungals is not common in intensive care units (ICUs) worldwide. The empirical use of echinocandins including anidulafungin is a recent trend.

Aim of the study

The objective of this study was to assess the impact of empirical anidulafungin in the development of invasive candidiasis in critically ill patients in ICU.

Methods

This retrospective case-control study was conducted on 149 patients with sepsis with/without septic shock and bacterial pneumonia. All the patients were divided into two groups. The ‘control group’ termed as ‘NEAT group’ received no empirical anidulafungin therapy and the ‘treated group’ termed as ‘EAT group’ received empirical anidulafungin therapy in early hospitalization hours.

Results

Seventy-two and 77 patients were divided into the control and the treated group, respectively. Patients in EAT group showed less incidences of IC (5.19%) than that of the NEAT group (29.17%) (p = 0.001). Here, the relative risk (RR) was 0.175 (95% CI, 0.064-0.493) and the risk difference (RD) rate was 24% (95% CI, 12.36%-35.58%). The 30-day all-cause mortality rate in NEAT group was higher (19.44%) than that of in EAT group (10.39%) (p = 0.04). Within the first 10-ICU-day, patients in the EAT group left ICU in higher rate (62.34%) than that in the NEAT group (54.17%).

Conclusion

Early empirical anidulafungin within 6 h of ICU admission reduced the risk of invasive candidiasis, 30-day all-cause mortality rate and increased ICU leaving rate within 10-day of ICU admission in critically ill patients.

Development of a Simple DNA Extraction Method and Candida Pan Loop-Mediated Isothermal Amplification Assay for Diagnosis of Candidemia

To reduce the morbidity and mortality of candidemia patients through rapid treatment, the development of a simple, rapid molecular diagnostic method that is based on nucleic acid extraction and is superior to conventional methods for detecting Candida in the blood is necessary. We developed a multiplex Candida Pan/internal control (IC) loop-mediated isothermal amplification (LAMP) assay and a simple DNA extraction boiling protocol using Chelex-100 that could extract yeast DNA in blood within 20 min. The Chelex-100/boiling method for DNA extraction showed comparable efficiency to that of the commercial QIAamp UCP Pathogen Mini Kit using Candida albicans qPCR. In addition, the Candida Pan/IC LAMP assay showed superior sensitivity to that of general Candida Pan and species qPCRs against clinical DNA samples extracted with the QIAamp UCP Pathogen Mini Kit and Chelex-100/boiling method. The Candida Pan/IC LAMP assay followed by Chelex-100/boiling-mediated DNA extraction showed high sensitivity (100%) and specificity (100%) against clinical samples infected with Candida. These results suggest that the Candida Pan/IC LAMP assay could be used as a rapid molecular diagnostic test for candidemia.

Clinical characteristics and outcome of candidemia: Experience from a tertiary referral center in Saudi Arabia

Background:

Candida bloodstream infections cause significant excess morbidity and mortality in the health-care setting. There is limited evidence regarding Candida species causing invasive infections in Saudi Arabia.

Objective:

To identify Candida species causing bloodstream infection and determine the clinical outcome and factors associated with mortality in a tertiary center in Saudi Arabia.

Materials and Methods:

This retrospective study included all cases of positive blood culture for Candida in patients admitted to King Abdulaziz Medical City, a tertiary care center in Riyadh, Saudi Arabia, between January 1, 2013 and June 30, 2019.

Results:

A total of 532 patients with candidemia were identified (male: 55.4%; mean age: 54 ± 26.2 years). The most common Candida species isolated was Candida albicans (26.7%), followed by Candida glabrata (22.7%), Candida parapsilosis (22.2%), and Candida tropicalis (18.4%). Non-albicans candidemia was more common in patients with diabetes (76.7%; P = 0.0560), neutropenia (89.8%; P = 0.0062), recent exposure to fluconazole (85.7%; P = 0.0394), and active chemotherapy (83.1%; P = 0.0128). In non-albicans, susceptibility to fluconazole varied from 95.9% with C. tropicalis to 41.5% with C. parapsilosis; nonetheless, all species were highly susceptible to echinocandins. The overall 30- and 90-day mortality rates were 39.9% and 56.4%, respectively. The mortality rate was nonsignificantly higher with non-albicans species at 30 days (41.2% vs. 35.9%; P = 0.2634) and 90 days (58.2% vs. 51.4%; P = 0.1620).

Conclusion:

This study found a changing pattern in the Candida species causing bloodstream infections and an epidemiological shift toward more non-albicans Candida species in Saudi Arabia.

Microbiome in human cancers

A microbiome is defined as the aggregate of all microbiota that reside in human digestive system and other tissues. This microbiota includes viruses, bacteria, fungi that live in various human organs and tissues like stomach, guts, oesophagus, mouth cavity, urinary tract, vagina, lungs, and skin. Almost 20 % of malignant cancers worldwide are related to microbial infections including bacteria, parasites, and viruses. The human body is constantly being attacked by microbes during its lifetime and microbial pathogens that have tumorigenic effects in 15-20 % of reported cancer cases. Recent scientific advances and the discovery of the effect of microbes on cancer as a pathogen or as a drug have significantly contributed to our understanding of the complex relationship between microbiome and cancer. The aim of this study is to overview some microbiomes that reside in the human body and their roles in cancer.

Computational Drug Repurposing Resources and Approaches for Discovering Novel Antifungal Drugs against Candida albicans N-Myristoyl Transferase

Candida albicans is a yeast that is an opportunistic fungal pathogen and also identified as ubiquitous polymorphic species that is mainly linked with major fungal infections in humans, particularly in the immunocompromised patients including transplant recipients, chemotherapy patients, HIV-infected patients as well as in low-birth-weight infants. Systemic Candida infections have a high mortality rate of around 29 to 76%. For reducing its infection, limited drugs are existing such as caspofungin, fluconazole, terbinafine, and amphotericin B, etc. which contain unlikable side effects and also toxic. This review intends to utilize advanced bioinformatics technologies such as Molecular docking, Scaffold hopping, Virtual screening, Pharmacophore modeling, Molecular dynamics (MD) simulation for the development of potentially new drug candidates with a drug-repurpose approach against Candida albicans within a limited time frame and also cost reductive.

In Vitro activity of ravuconazole against Candida auris and vaginal candida isolates

BACKGROUND

Ravuconazole is an extended-spectrum triazole agent that is efficient in vitro against Candida spp. and has been approved to work as an oral formulae for onychomycosis in Japan in 2018. However, nobody had determined the MIC of ravuconazole against the Candida auris, which is known as an emerging multidrug-resistant yeast. Meanwhile, rare is known of the in vitro activity of ravuconazole against vaginal Candida isolates.

OBJECTIVES

To investigate the activity of ravuconazole against C. auris and vaginal Candida isolates of China and assess the feasibility of ravuconazole in the treatment of candidiasis caused by C. auris and other Candida spp.

METHODS

We determined the in vitro activity of ravuconazole and 9 comparators against 15 C. auris isolates and determined the MIC of ravuconazole on 525 vaginal Candida isolates (Candida albicans, Candida tropicalis, Candida glabrata and Candida parapsilosis) from 9 provinces of China by Clinical and Laboratory Standards Institute (CLSI) methodology.

RESULTS

The MICs of fluconazole and amphotericin B on C. auris were much higher than second-generation azoles and echinocandins. Ravuconazole was active against all the C. auris isolates and as effective as isavuconazole, posaconazole and echinocandins while showed a better antifungal activity than itraconazole, voriconazole to C. auris. For vaginal Candida isolates, the proportion of ravuconazole-resistant isolates is 0.19% (1/525).

CONCLUSIONS

Ravuconazole was in good active against C. auris and vaginal Candida isolates, which suggested ravuconazole could be used in the treatment of drug-resistant candidiasis.

Antifungal Resistance of Candida Species Isolated from HIV Patients in a Tertiary Care Hospital, Mysuru, Karnataka

Context:

Candidiasis still remains as a common opportunistic infection in patients with human immunodeficiency virus (HIV). Drug resistance has become a serious health concern because of indiscriminate usage and dosage.

Aim:

To determine the antifungal resistance pattern of Candida albicans and non-albicans Candida (NAC) from HIV patients.

Subjects and Methods:

The study was carried out in the department of microbiology at a tertiary care hospital. Candida isolates obtained from HIV patients were tested for drug susceptibility by Vitek-2 automated system.

Results:

Antifungal susceptibility pattern (n=109) revealed that 15% of the isolates were resistant to at-least one and 85% were sensitive to all the drugs tested. About 10% and 19% of C. albicans showed resistance to fluconazole and flucytosine respectively. Among non-albicans tested, only C. tropicalis (14%) exhibited resistance to flucytosine.

Conclusions:

Knowledge on epidemiology, species prevalence, and drug resistance pattern may guide for effective therapy. This reduces morbidity and also improves the quality of life.

Analysis of fungal bloodstream infection in intensive care units in the Meizhou region of China: species distribution and resistance and the risk factors for patient mortality

Background

Fungal bloodstream infections (FBI) among intensive care unit (ICU) patients are increasing. Our objective was to characterize the fungal pathogens that cause bloodstream infections and determine the epidemiology and risk factors for patient mortality among ICU patients in Meizhou, China.

Methods

Eighty-one ICU patients with FBI during their stays were included in the study conducted from January 2008 to December 2017. Blood cultures were performed and the antimicrobial susceptibility profiles of the resulting isolates were determined. Logistic multiple regression and ROC curve analysis were used to assess the risk factors for mortality among the cases.

Results

The prevalence of FBI in ICU patients was 0.38% (81/21,098) with a mortality rate of 36% (29/81). Ninety-eight strains of bloodstream-infecting fungi, mainly Candida spp., were identified from these patients. Candida albicans was most common (43%). Two strains of C. parapsilosis were no-sensitive to caspofungin, C. glabrata were less than 80% sensitive to azole drugs. Logistic multiple regression showed that age, serum albumin, APACHE II score, three or more underlying diseases, and length of stay in ICU were independent risk factors for mortality in FBI. ROC curve analysis showed that APACHE II scores > 19 and serum albumin ≤25 g/L were the best predictors of mortality.

Conclusion

Candida spp. predominated with high mortality rates among cases of FBI in ICU. Thus, clinical staff should enhance overall patient monitoring and concurrently monitor fungal susceptibility to reduce mortality rates.

In vitro antifungal susceptibilities of six antifungal drugs against clinical Candida glabrata isolates according to EUCAST

Background and Purpose:

Candida glabrata is the second cause of candidiasis. The mortality rate of C. glabrata infections is about 40%; accordingly, it may be life threatening, especially in immunocompromised hosts. Regarding this, the current study was conducted to evaluate the regional patterns of the antifungal susceptibility of clinical C. glabrataisolated from the patients referring to the health centers located in Ahvaz, Iran

Materials and Methods:

In this study, a total of 30 clinical strains of C. glabrata isolates were recovered from different body sites (i.e., vagina, mouth, and urine). Phenotypic characteristics and molecular methods were used to identify the isolates. The minimum inhibitory concentration (MIC) was determined according to the European Committee on Antimicrobial Susceptibility Testing

Results:

Our findings demonstrated that 20%, 80%, and 6.7% of the isolates were resistant to amphotericin B, terbinafine, and posaconazole, respectively, while all the isolates were found to be fluconazole susceptible dose dependent and susceptible to voriconazole and caspofungin

Conclusion:

Our study suggested that voriconazole had high potency against C. glabrata isolates. Consequently, this antifungal agent can be an alternative drug in the treatment of resistant patients. These results can be helpful for the successful treatment of patients in different regions

Candida Bloodstream Infection: Changing Pattern of Occurrence and Antifungal Susceptibility over 10 Years in a Tertiary Care Saudi Hospital

Background

Candida has emerged as one of the most important pathogens that cause bloodstream infection (BSI).Understanding the current Candida BSI trends, the dominant species causing disease and the mortality associated with this infection are crucial to optimize therapeutic and prophylaxis measures.

Objectives

To study the epidemiology and to evaluate the risk factors, prognostic factors, and mortality associated with candidemia and to compare these findings with previously published studies from Saudi Arabia.

Design

A retrospective medical record review.

Setting

Tertiary hospital in Riyadh.

Patients and Methods

The analysis included all cases of Candida blood stream infection who are >18 years old over the period from 2013 to 2018. Continuous variables were compared using the parametric T-test while categorical variables were compared using the Chi-squared test.

Main Outcome Measure

Incidence, resistance, and hospital outcomes in Candida blood stream infection.

Sample Size

324 patients.

Results

Three hundred and twenty-four episodes of Candida blood stream infections were identified. Median age of patients was 49.7 SD ± 28.1 years, and 53% of patients were males. More than half of the patients had an underlying disease involving the abdomen or laparotomy, 78% had an indwelling intravenous catheter, and 62% had suffered a bacterial infection within 2 weeks prior to candidemia. Candida albicans represents 33% of all isolates with decreasing trend overtime. There was an increase in the number of nonalbicans Candida overtime with Candida tropicalis in the lead (20%). Use of broad spectrum antibiotics (82%), prior ICU admission (60%) and use of central venous catheters (58%) were the most prevalent predisposing factors of candidemia. Azole resistance was variable overtime. Resistance to caspofungin remained very low (1.9%). Fourteen days crude mortality was 37% for ICU patients and 26.7% in non-ICU patients, while hospital crude mortality was 64.4% and 46.7%, respectively.

Conclusion

There is an increasing trend of nonalbicans Candida blood stream infection. Fluconazole resistance remained low to C. albicans. Most isolates remain susceptible to caspofungin, voriconazole, and amphotericin B. Candida bloodstream infection is associated with high 14-day hospital mortality.

In vitro synergy of echinocandins with triazoles against fluconazole-resistant Candida parapsilosis complex isolates

INTRODUCTION

Candida parapsilosis (C. parapsilosis) is a common non-albicans Candida species ranked as the second common cause of bloodstream infections. Azole resistance and elevated echinocandin MICs have been reported for these fungi. This study was conducted to determine the interactions between azoles and echinocandins against C. parapsilosis species complex.

MATERIALS AND METHODS

Fifteen fluconazole-resistant clinical isolates of C. parapsilosis complex were included: C. parapsilosis sensu stricto (n = 7), C. orthopsilosis (n = 5) and C. metapsilosis (n = 3). The activity of azoles (fluconazole, itraconazole) and echinocandins (anidulafungin, micafungin) alone and in combination was determined using checkerboard broth microdilution. The results were determined based on the fractional inhibitory concentration index (FICI).

RESULTS

In vitro combination of fluconazole with anidulafungin was found to be synergistic (FICI 0.07-0.37) and decreased the MIC range from 4-64 μg/mL to 0.5-16 μg/mL for fluconazole and from 2-8 μg/mL to 0.125-1 μg/mL for anidulafungin. Similarly, interactions of fluconazole with micafungin (FICI 0.25-0.5), itraconazole with anidulafungin (FICI 0.15-0.37) and itraconazole with micafungin (FICI 0.09-0.37) were synergistic.

CONCLUSION

The combination of fluconazole and itraconazole with either anidulafungin or micafungin demonstrated synergistic interactions against C. parapsilosis species complex, especially against isolates with elevated MIC values. However, the use of these combinations in clinical practice and the clinical relevance of in vitro combination results remain unclear.

Impact of manganese on biofilm formation and cell morphology of Candida parapsilosis clinical isolates with different biofilm forming abilities

The commensal species Candida parapsilosis is an emerging human pathogen that has the ability to form biofilms. In this study, we explored the impact of the divalent cations cobalt (Co²⁺), copper (Cu²⁺), iron (Fe³⁺), manganese (Mn²⁺), nickel (Ni²⁺) and zinc (Zn²⁺) on biofilm formation of clinical isolates of C. parapsilosis with no, low and high biofilm forming abilities at 30 and 37°C. All strains besides one isolate showed a concentration-dependent enhancement of biofilm formation at 30°C in the presence of Mn²⁺ with a maximum at 2 mM. The biofilm forming ability of no and low biofilm forming isolates was >2-fold enhanced in the presence of 2 mM Mn²⁺, while the effect in high biofilm forming isolate was significantly less pronounced. Of note, cells in the biofilms of no and low biofilm forming strains differentiated into yeast and pseudohyphal cells similar in morphology to high biofilm formers. The biofilm transcriptional activator BCR1 has a dual developmental role in the absence and presence of 2 mM Mn²⁺ as it promoted biofilm formation of no biofilm forming strains, and, surprisingly, suppressed cells of no biofilm forming strains to develop into pseudohyphae and/or hyphae. Thus, environmental conditions can significantly affect the amount of biofilm formation and cell morphology of C. parapsilosis with Mn²⁺ to overcome developmental blocks to trigger biofilm formation and to partially relieve BCR1 suppressed cell differentiation.

Development of a new stability indicating method for the simultaneous separation of voriconazole from its impurities along with sodium benzoate used as a preservative in a powder for oral suspension

Voriconazole is a second-generation triazole derived from fluconazole, having an enhanced antifungal spectrum, compared with older triazoles. It is the drug of choice for treatment of invasive aspergillosis and many Scedosporium/Pseudallescheria Fusarium infections. Voriconazole is available in both intravenous and oral formulations. Since there is much interest in pharmaceutical quality control, separation of impurities from the main drug substances and accurate assay quantification, and since there is no reference or monograph until nowadays reported for the simultaneous separation of voriconazole from its specified and unspecified impurities along with sodium benzoate used as an antimicrobial preservative, our aim of this work is to develop a new simple, sensitive and stability indicating assay method allowing thus separation by high-performance liquid chromatography. The development of our method consisted in optimizing the following analytical parameters: nature and composition of the mobile phase, its pH, buffer concentration, nature of the stationary phase, column temperature and detection wavelength. After optimisation, separation was achieved on a stainless steel column NOVAPACK C18 (3.9mm×150mm; 4μm particle size) using a gradient mode with methanol, acetonitrile R and an aqueous solution acidified by acetic acid at 1% and adjusted to pH 2.77. The eluted compounds were monitored at 254nm. The flow rate was set at 1.0mL/min, the injection volume at 10μL, and the column oven temperature was maintained at 35°C. Under these conditions, separation was achieved with good resolution and symmetrical peaks' shape. The developed method was validated according to the International Conference on Harmonization (ICH) guidelines, and then it was successfully applied to establish inherent stability of the pharmaceutical formulation subjected to different ICH prescribed stress conditions. The developed method was proved to be simple, specific and precise. Hence, it can be considered as a method for stability study and for routine quality control analysis of voriconazole and sodium benzoate in a powder for oral suspension.

A Novel Virulence Phenotype Rapidly Assesses Candida Fungal Pathogenesis in Healthy and Immunocompromised Caenorhabditis elegans Hosts

Opportunistic pathogens are commensals capable of causing disease and are serious threats to human health. It is critical to understand the mechanisms and host contexts under which opportunistic pathogens become virulent. In this work, we present a novel assay to quickly and quantitatively measure pathogen virulence in healthy and immunocompromised nematode hosts. We found that Candida species, one of the most prominent fungal opportunistic pathogens of humans, decrease host fitness by reducing survival and impacting host reproduction. Most importantly, by measuring virulence in hosts that have intact or compromised immune function, we can reveal the pathogenic potential of opportunistic fungal pathogens.

The yeast Candida albicans is an opportunistic pathogen of humans, meaning that despite commensal interactions with its host, it can transition to a harmful pathogen. While C. albicans is the predominant species isolated in the human gastrointestinal mycobiome and is implicated in fungal infection, infections due to non-albicans Candida species are rapidly rising. Studying the factors that contribute to virulence is often challenging and frequently depends on many contexts, including host immune status and pathogen genetic background. Here, we utilize the nematode Caenorhabditis elegans as a perspicuous and efficient model host system to study fungal infections of Candida pathogens. We find that, in addition to reducing lifetime host survival, exposure to C. albicans results in delayed reproduction, which significantly reduced lineage growth over multiple generations. Furthermore, we assessed fungal pathogen virulence in C. elegans hosts compromised for innate immune function and detected increased early mortality, reduced brood sizes, and delayed reproduction relative to infected healthy hosts. Importantly, by assessing virulence in both healthy and immunocompromised host backgrounds, we reveal the pathogen potential in non-albicans Candida species. Taken together, we present a novel lineage growth assay to measure reduction in host fitness associated with fungal infection and demonstrate significant interactions between pathogen and host immune function that contribute to virulence.

IMPORTANCE Opportunistic pathogens are commensals capable of causing disease and are serious threats to human health. It is critical to understand the mechanisms and host contexts under which opportunistic pathogens become virulent. In this work, we present a novel assay to quickly and quantitatively measure pathogen virulence in healthy and immunocompromised nematode hosts. We found that Candida species, one of the most prominent fungal opportunistic pathogens of humans, decrease host fitness by reducing survival and impacting host reproduction. Most importantly, by measuring virulence in hosts that have intact or compromised immune function, we can reveal the pathogenic potential of opportunistic fungal pathogens.

Antifungal Susceptibility Profile of Candida Albicans Isolated from Vulvovaginal Candidiasis in Xinjiang Province of China

We investigated the antifungal susceptibility profiles of 207 independent Candida albicans strains isolated from patients with vulvovaginal candidiasis (VVC) in Xinjiang Province of China. Using CLSI M27-A3 and M27-S4 guidelines, anidulafungin and micafungin were the most active drugs against C. albicans showing an MIC₅₀/MIC₉₀ corresponding to 0.016/0.0313 µg/mL, followed by caspofungin (0.25/0.25 µg/mL), posaconazole (0.125/0.5 µg/mL), ravuconazole (0.063/1 µg/mL), itraconazole (0.125/1 µg/mL), amphotericine B (0.5/1 µg/mL), isavuconazole (0.063/2 µg/mL), 5-flucytosine (1/2 µg/mL), voriconazole (0.125/4 µg/mL), and fluconazole (0.5/4 µg/mL). 96.1% (199)-100.0% (207) isolates were sensitive to the three echinocandins tested, amphotericine B and 5-flucytosine. The in vitro activity of triazoles against all isolates tested was variable; itraconazole and voriconazole had reduced the activity to almost half of the isolates (55.1% (114) and 51.2% (106) susceptible, respectively). Fluconazole was active against 76.3% (158) isolates tested. The new triazoles ravuconazole, isavuconazole and posaconazole showed good in vitro potency against 89.9% (186)-95.2% (197) of isolates with the geometric mean MIC (µg/mL) of 0.10, 0.12 and 0.14 µg/mL, respectively. In conclusion, our study indicates that for effective management of systemic candidiasis in Xinjiang Province of China, it is important to determine the susceptibility profiles of isolated C. albicans from patients with VVC.

Mechanisms of azole resistance in clinical isolates of Candida glabrata from two hospitals in China

Purpose: Candida glabrata has emerged as the second or third most common non-albicans species responsible for an increasing number of systemic infections. Moreover, its high-level of resistance to azole is associated with a high mortality rate. This study aimed to evaluate nosocomial infections and resistance characteristics of C. glabrata and to explore the mechanism of azole resistance in C. glabrata.

Patients and methods: Fifty-nine clinical C. glabrata isolates were collected from two hospitals in China. The susceptibility of the strains to antifungal agents was determined by both the ATB Fungus 3 strip and CLSI M27 broth microdilution method. Efflux of rhodamine 6G was examined to evaluate the effects of efflux pumps. The expression levels of CgCDR1, CgCDR2, CgSNQ2, CgERG11, and CgPDR1 were examined by real-time PCR. The sequences of CgERG11 and CgPDR1 were determined by PCR-based DNA sequencing.

Results: All 59 isolates of C. glabrata were susceptible to flucytosine and amphotericin B. Twelve (20.3%) isolates were determined to be fluconazole-resistant, whereas 13 (22.0%) and 27 (45.7%) isolates were categorized as non-wild-type for itraconazole and voriconazole, respectively. Efflux pumps in azole-resistant isolates showed stronger effects than those in azole-susceptible-dose dependent isolates, which is consistent with the significant upregulation of CgCDR1 and CgCDR2 (P<0.05), whereas no obvious differences were found for CgSNQ2, CgERG11, and CgPDR1 (P>0.05). Sequencing of CgERG11 showed no alteration favoring the hypothesis that CgERG11 is not involved in the azole resistance of C. glabrata. Four CgPDR1 missense mutations were found in azole-resistant isolates, of which the high frequency of the CgPDR1 mutation, A848V, has not been reported previously.

Conclusion: Efflux pump function is the main mechanism of resistance to fluconazole in our collected clinical isolates of C. glabrata, and further studies of the related gene disruption and genome-wide expression are needed to verify the function.

Candida glabrata Fungemia Following Robotic Total Laparoscopic Hysterectomy and Bilateral Salpingo-oophorectomy in a Patient with Recurrent Vulvovaginitis: A Case Report

Vulvovaginal candidiasis is a common gynecologic diagnosis that can be treated empirically with fluconazole. We present a patient that developed post-operative Candida glabrata (C. glabrata) fungemia after being empirically treated for vulvuovaginal candidiasis with fluconazole multiple times throughout the year prior to robotic total laparoscopic hysterectomy and bilateral salpingo-oophorectomy. C. glabrata is becoming increasingly resistant to azole antimycotic therapy. It is likely that this patient had undertreated fluconazole-resistant C. glabrata vulvovaginitis prior to surgery, and that the pelvic infection was the source of fungemia.

ERG11 gene polymorphisms and susceptibility to fluconazole in Candida isolates from diabetic and kidney transplant patients

INTRODUCTION

Candidiasis is the most frequent opportunistic mycosis in humans and can cause mortality, particularly in immunodeficient patients. One major concern is the increasing number of infections caused by drug-resistant Candidas trains, as these cannot be efficiently treated with standard therapeutics. The most common mechanism of fluconazole resistance in Candida is mutation of ERG11, a gene involved in the biosynthesis of ergosterol, a compound essential for cell integrity and membrane function.

METHODS

Based on this knowledge, we investigated polymorphisms in the ERG11 gene of 3 Candida species isolated from immunocompromised and immunocompetent patients. In addition, we correlated the genetic data with the fluconazole susceptibility profile of the Candida isolates.

RESULTS

A total of 80 Candida albicans, 8 Candida tropicalis and 6 Candida glabrata isolates were obtained from the saliva of diabetic, kidney transplant and immunocompetent patients. Isolates were considered susceptible to fluconazole if the minimum inhibitory concentration was lower than 8 μg/mL. The amino acid mutations F105L, D116E, K119N, S137L, and K128T were observed in C. albicans isolates, and T224C and G263A were found in C. tropicalis isolates.

CONCLUSIONS

Despite the high number of polymorphisms observed, the mutations occurred in regions that are not predicted to interfere with ergosterol synthesis, and therefore are not related to fluconazole resistance.

A Transcriptomics Approach To Unveiling the Mechanisms of In Vitro Evolution towards Fluconazole Resistance of a Candida glabrata Clinical Isolate

Candida glabrata is an emerging fungal pathogen. Its increased prevalence is associated with its ability to rapidly develop antifungal drug resistance, particularly to azoles.

Candida glabrata is an emerging fungal pathogen. Its increased prevalence is associated with its ability to rapidly develop antifungal drug resistance, particularly to azoles. In order to unravel new molecular mechanisms behind azole resistance, a transcriptomics analysis of the evolution of a C. glabrata clinical isolate (isolate 044) from azole susceptibility to posaconazole resistance (21st day), clotrimazole resistance (31st day), and fluconazole and voriconazole resistance (45th day), induced by longstanding incubation with fluconazole, was carried out. All the evolved strains were found to accumulate lower concentrations of azole drugs than the parental strain, while the ergosterol concentration remained mostly constant. However, only the population displaying resistance to all azoles was found to have a gain-of-function mutation in the C. glabrataPDR1 gene, leading to the upregulation of genes encoding multidrug resistance transporters. Intermediate strains, exhibiting posaconazole/clotrimazole resistance and increased fluconazole/voriconazole MIC levels, were found to display alternative ways to resist azole drugs. Particularly, posaconazole/clotrimazole resistance after 31 days was correlated with increased expression of adhesin genes. This finding led us to identify the Epa3 adhesin as a new determinant of azole resistance. Besides being required for biofilm formation, Epa3 expression was found to decrease the intracellular accumulation of azole antifungal drugs. Altogether, this work provides a glimpse of the transcriptomics evolution of a C. glabrata population toward multiazole resistance, highlighting the multifactorial nature of the acquisition of azole resistance and pointing out a new player in azole resistance.

Efficacy and safety of fosravuconazole L-lysine ethanolate, a novel oral triazole antifungal agent, for the treatment of onychomycosis: A multicenter, double-blind, randomized phase III study

Fosravuconazole L‐lysine ethanolate (F‐RVCZ) is a prodrug of ravuconazole, a novel triazole antifungal agent, exerting broad and potent antifungal activity. The efficacy and safety of F‐RVCZ, compared with a placebo, were investigated in a multicenter, double‐blind, randomized study of Japanese onychomycosis patients with 25% or more clinical involvement of the target toenail. Subjects (n = 153) were randomly assigned to receive F‐RVCZ (100 mg RVCZ, n = 101) or placebo (n = 52) p.o. once daily for 12 weeks. The primary end‐point was the rate of complete cure (clinical cure [0% clinical involvement of the target toenail] plus mycological cure [negative potassium hydroxide examination]) at week 48 (36‐week post‐treatment visit). Secondary end‐points were changes over time in the efficacy and mycological effect of F‐RVCZ. Safety was also evaluated. The complete cure rate at week 48 was significantly higher with F‐RVCZ (59.4%, 60/101) than the placebo (5.8%, 3/52) in the full analysis set (P < 0.001). The mycological cure rate at week 48 was also significantly higher with F‐RVCZ (82.0%, 73/89) than the placebo (20.0%, 10/50, P < 0.001). Regarding safety, adverse events were observed in 83.2% (84/101) and 80.8% (42/52), and adverse drug reactions (ADR) in 23.8% (24/101) and 3.8% (2/52) of F‐RVCZ and placebo subjects, respectively. ADR were mild to moderate in severity, with none being serious. F‐RVCZ (equivalent to 100 mg ravuconazole) administrated once daily for 12 weeks was more effective than placebo and tolerable in patients with onychomycosis, suggesting it to be a promising drug for onychomycosis treatment.

Profiling of PDR1 and MSH2 in Candida glabrata Bloodstream Isolates from a Multicenter Study in China

Among 158 Candida glabrata bloodstream isolates collected from numerous centers in China, a resistance to fluconazole was seen in 8.9%. Three isolates (1.9%) were resistant to all echinocandins. Multilocus sequence typing (MLST) revealed that sequence type 7 ([ST7] 65.8%) was the most common type, followed by ST3 (7.6%). PDR1 polymorphisms were associated with the acquisition of fluconazole resistance in C. glabrata isolates, while MSH2 polymorphisms were associated with the STs and microsatellite genotypes, irrespective of fluconazole resistance.

Identification of Candida glabrata complex species: use of Vitek MS® RUO & Bruker ClinproTools®

AIM

Distinction of species within the Candida glabrata complex (i.e., C. glabrata sensu stricto, Candida nivariensis and Candida bracarensis) is relevant for epidemiological purposes and antifungal management.

MATERIALS & METHODS

Two commercial matrix-assisted laser desorption ionization-time of flight mass spectrometry systems were comprehensively evaluated for the identification of fungi within this complex.

RESULTS

None of the species (C. nivariensis and C. bracarensis) were identified correctly by Vitek mass spectrometry (MS^®) v2.0 In Vitro Diagnosis system and Bruker Biotyper MS^® v3.1, but all were correct by the Vitek MS^® Research Use Only system. The Bruker ClinProTools software showed 100% recognition capability and cross validation for the discrimination of C. nivariensis and C. bracarensis.

CONCLUSION

Using Vitek MS Research Use Only and Bruker ClinProTools can overcome limitations of the Vitek MS In Vitro Diagnosis and Bruker Biotyper databases in the identification of C. glabrata complex.

Candidemia in Febrile Neutropenic Patients; a Brief Report

INTRODUCTION

Febrile neutropenic patients are at risk of serious infections. The aim of the present study is to identify the frequency, species, and susceptibility patterns of candidemia in febrile neutropenic patients.

METHODS

This cross-sectional study was conducted on febrile neutropenic patients suspected with candidemia who had been referred to 3 educational hospitals during 9 months.

RESULTS

The blood samples of 80 febrile neutropenic patients with the mean age of 48±16.6 years were studied (60% female). Five (6.25%) episodes of candidemia were identified. The underlying disease was acute myeloid leukemia in 4 (80%) cases and all 5(100%) cases had central venous catheter and were receiving prophylactic ciprofloxacin and acyclovir. 100% of isolates were found to be susceptible to Voriconazole, 80% to Caspofungin, 60% to Amphotericin B, and 40% to Fluconazole.

CONCLUSION

The frequency of candidemia among the studied febrile neutropenia patients was 6.25%, with 80% mortality rate, and the most frequently identified yeast was Candida albicans (100% susceptible to Voriconazole).

Potential of Ravuconazole and its Prodrugs as the New OralTherapeutics for Onychomycosis

Onychomycosis is a fungal infection of the nail apparatus caused by dermatophytes, Candida and non-dermatophytic molds. It is highly prevalent in the general population worldwide and also responsible for significant morbidity and complications and does not usually cure itself. Thus, the condition needs to be treated in view of physical and psychological problems produced. Currently, oral medications using terbinafine are the most effective therapy, but it has relatively limited therapeutic success, particularly for long-term management. Such existing oral therapies are associated with high recurrence rates and treatment failure, as well as with potential adverse events and drug-drug interactions. In the light of these issues, development of more efficacious and safer alternatives for the treatment of onychomycosis is warranted.Ravuconazole and its prodrugs are promising new drug candidates for oral therapy of onychomycosis, among which a water-soluble prodrug, mono-lysine phosphoester derivative (E1224 or BFE1224) is in the most advanced stage of clinical development; a Phase II dose-finding study has been successfully completed and Phase III comparative studies are in progress in Japan.This review aims to summarize our current status of knowledge and information on ravuconazole and its prodrugs, particularly BFE1224, as the potential oral treatment option for onychomycosis. It also summarize the clinical features of onychomycosis with particular stress on its etiology, epidemiology, and current therapeutic options and their limitations. Given its clinical usefulness, BFE1224 may become a valuable addition to the current armamentarium for the treatment of onychomycosis.

Voriconazole

Each month, subscribers to The Formulary Monograph Service receive five to six well-documented monographs on drugs that are newly released or are in late Phase III trials. The monographs are targeted to your Pharmacy and Therapeutics Committee. Subscribers also receive monthly one-page summary monographs on the agents that are useful for agendas and pharmacy/nursing in-ser-vices. A comprehensive target drug utilization evaluation (DUE) is also provided each month. The monographs are published in printed form and on diskettes that allow customization. Subscribers to the The Formulary Monograph Service also receive access to a pharmacy bulletin board, The Formulary Information Exchange (The F.I.X.). All topics pertinent to clinical and hospital pharmacy are discussed on The F.I.X.

Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. If you would like information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The September 2002 monograph topics are ziprasidone mesylate for injection; lanthanum carbonate, artesunate rectal capsules, ZD1839, and memantine. The DUE is on ziprasidone.

Identification and susceptibility testing of Candida spp. directly from yeast-positive blood cultures with Vitek 2

Culture-based identification and antifungal susceptibility take 48-72hours after positivity. We analyzed the performance of Vitek2 directly from 40 yeast-positive blood-cultures; agreement of 100% was observed for the tested antifungals; identification showed the same species in 31/40. The method reduces time (13 to 18h) for preliminary results.

Risk of Fungal Infection to Dental Patients

Fungi can cause various diseases, and some pathogenic fungi have been detected in the water of dental equipment. This environment offers suitable conditions for fungal biofilms to emerge, which can facilitate mycological contamination. This study verified whether the water employed in the dental units of two dental clinics at the University of Franca was contaminated with fungi. This study also evaluated the ability of the detected fungi to form biofilms. The high-revving engine contained the largest average amount of fungi, 14.93 ± 18.18 CFU/mL. The main fungal species verified in this equipment belonged to the genera Aspergillus spp., Fusarium spp., Candida spp., and Rhodotorula spp. Among the isolated filamentous fungi, only one fungus of the genus Fusarium spp. did not form biofilms. As for yeasts, all the Candida spp. isolates grew as biofilm, but none of the Rhodotorula spp. isolates demonstrated this ability. Given that professionals and patients are often exposed to water and aerosols generated by the dental procedure, the several fungal species detected herein represent a potential risk especially to immunocompromised patients undergoing dental treatment. Therefore, frequent microbiological monitoring of the water employed in dental equipment is crucial to reduce the presence of contaminants.

Advances in Candida detection platforms for clinical and point-of-care applications

Invasive candidiasis remains one of the most serious community and healthcare-acquired infections worldwide. Conventional Candida detection methods based on blood and plate culture are time-consuming and require at least 2-4 days to identify various Candida species. Despite considerable advances for candidiasis detection, the development of simple, compact and portable point-of-care diagnostics for rapid and precise testing that automatically performs cell lysis, nucleic acid extraction, purification and detection still remains a challenge. Here, we systematically review most prominent conventional and nonconventional techniques for the detection of various Candida species, including Candida staining, blood culture, serological testing and nucleic acid-based analysis. We also discuss the most advanced lab on a chip devices for candida detection.

Molecular Epidemiology and Antifungal Susceptibility of Candida glabrata in China (August 2009 to July 2014): A Multi-Center Study

Candida glabrata is an increasingly important cause of invasive candidiasis. In China, relatively little is known of the molecular epidemiology of C. glabrata and of its antifungal susceptibility patterns. Here we studied 411 non-duplicate C. glabrata isolates from 411 patients at 11 hospitals participating in the National China Hospital Invasive Fungal Surveillance Net program (CHIF-NET; 2010-2014). Genotyping was performed using multilocus sequence typing (MLST) employing six genetic loci and by microsatellite analysis. Antifungal susceptibility testing was performed using Sensititre YeastOne™ YO10 methodology. Of 411 isolates, 35 sequence types (ST) were identified by MLST and 79 different genotypes by microsatellite typing; the latter had higher discriminatory power than MLST in the molecular typing of C. glabrata. Using MLST, ST7 and ST3 were the most common STs (66.4 and 9.5% of all isolates, respectively) with 24 novel STs identified; the most common microsatellite types were T25 (30.4% of all isolates) and T31 (12.4%). Resistance to fluconazole (MIC > 32 μg/mL) was seen in 16.5% (68/411) of isolates whilst MICs of >0.5 μg/mL for voriconazole, >2 μg/mL for itraconazole and >2 μg/mL for posaconazole were seen for 28.7, 6.8, and 7.3% of isolates, respectively; 14.8% of all isolates cross-resistant/non-wide-type to fluconazole and voriconazole. Fluconazole resistant rates increased 3-fold over the 5-year period whilst that of isolates with non-WT MICs to voriconazole, 7-fold. All echinocandins exhibited >99% susceptibility rates against all isolates but notably one isolate exhibited multi-drug resistance to the azoles and echinocandins. The study has provided a global picture of the molecular epidemiology and drug resistance rates of C. glabrata in China during the period of the study.

Revisiting Species Distribution and Antifungal Susceptibility of Candida Bloodstream Isolates from Latin American Medical Centers

The epidemiology of candidemia varies geographically, and there is still scarce data on the epidemiology of candidemia in Latin America (LA). After extensive revision of medical literature, we found reliable and robust information on the microbiological aspects of candidemia in patients from 11 out of 21 medical centers from LA countries and 1 out of 20 from Caribbean countries/territories. Based on 40 papers attending our search strategy, we noted that C. albicans remains the most common species causing candidemia in our region, followed by C. parapsilosis and C. tropicalis. In Argentina, Brazil, and Colombia, a trend towards an increase in frequency of C. glabrata candidemia was observed. Although resistance rates to fluconazole is under 3%, there was a slight increase in the resistance rates to C. albicans, C. parapsilosis and C. tropicalis isolates. Echinocandin resistance has been reported in a few surveys, but no single study confirmed the resistant phenotype reported by using molecular methods. We highlight the importance of conducting continuous surveillance studies to identify new trends in terms of species distribution of Candida and antifungal resistance related to episodes of candidemia in LA. This information is critical for helping clinicians to prevent and control Candida bloodstream infections in their medical centers.

Candida glabrata Biofilms: How Far Have We Come?

Infections caused by Candida species have been increasing in the last decades and can result in local or systemic infections, with high morbidity and mortality. After Candida albicans, Candida glabrata is one of the most prevalent pathogenic fungi in humans. In addition to the high antifungal drugs resistance and inability to form hyphae or secret hydrolases, C. glabrata retain many virulence factors that contribute to its extreme aggressiveness and result in a low therapeutic response and serious recurrent candidiasis, particularly biofilm formation ability. For their extraordinary organization, especially regarding the complex structure of the matrix, biofilms are very resistant to antifungal treatments. Thus, new approaches to the treatment of C. glabrata's biofilms are emerging. In this article, the knowledge available on C. glabrata's resistance will be highlighted, with a special focus on biofilms, as well as new therapeutic alternatives to control them.

Epidihydropinidine, the main piperidine alkaloid compound of Norway spruce (Picea abies) shows promising antibacterial and anti-Candida activity

This study reports for the first time promising antibacterial and antifungal effects of epidihydropinidine, the major piperidine alkaloid in the needles and bark of Norway spruce, Picea abies (L.) Karsten. Epidihydropinidine was growth inhibitory against all bacterial and fungal strains used in our investigation, showing the lowest MIC value of 5.37μg/mL against Pseudomonas aeruginosa, Enterococcus faecalis, Candida glabrata and C. albicans. Epidihydropinidine was nearly three times more active than tetracycline against P. aeruginosa and E. faecalis. Promising antibacterial effects were also recorded against Staphylococcus aureus and Bacillus cereus (MIC 10.75μg/mL) as well as against Salmonella enterica (MIC and MBC 43μg/mL). Our preliminary results suggest that epidihydropinidine as well related alkaloids of Norway spruce could be powerful candidates for new antibiotics and for preventing food spoilage.

Evaluation of epidemiological characteristics and risk factors affecting mortality in patients with candidemia

BACKGROUND/AIM

The aim of this study was to determine epidemiologic characters of patients with candidemia and to evaluate risk factors that can affect mortality rates among these patients.

MATERIALS AND METHODS

Patients admitted to the İstanbul Medeniyet University Göztepe Training Hospital between 2009 and 2011 who had a positive blood culture for Candida spp. during hospitalization were studied retrospectively for demographic characteristics and risk factors. Statistical comparisons were estimated with the Stata 12 package. Independent variables associated with mortality were estimated by Cox regression analyses.

RESULTS

A total of 89 patients were identified with a positive blood culture. Of the isolates, 72% (64/89) were C. albicans and 10% (9/89) were non-albicans Candida, while 18% (16/89) were unidentified. C. parapsilosis was the most frequently isolated species among non-albicans Candida. The crude mortality rate among candidemia cases was 30% (27/89). By univariate analysis, being in the ICU and age (≥50 or ≥60) were found to be statistically significant, whereas by multivariate analysis only age of ≥50 years was independently more associated with mortality (OR, 2.7; CI, 1.05-6.73).

CONCLUSION

Candidemia is associated with high mortality rates. Patients older than 50 years are found to be at considerable risk in terms of adverse outcomes.

Epidemiology, microbiology, clinical characteristics, and outcomes of candidemia in internal medicine wards-a retrospective study

BACKGROUND

The clinical characteristics of internal medicine ward (IMW) patients with candidemia are unclear. The aim of this study was to define the clinical characteristics of candidemic IMW patients and to study the incidence, species distribution, and outcomes of these patients compared to surgical and intensive care unit (ICU) candidemic patients.

METHODS

A retrospective cohort of candidemic patients in IMWs, general surgery wards, and an ICU at Beilinson Hospital during the period 2007-2014 was analyzed.

RESULTS

A total of 118 patients with candidemia were identified in six IMWs, two general surgery wards, and one ICU in the hospital. Candida albicans was the leading causative agent (41.1%). Higher proportions of Candida parapsilosis and Candida tropicalis isolates were observed in the IMW patients. IMW patients were significantly older, with poorer functional capacity, and had more frequently been exposed to antibiotic therapy within 90 days, in particular β-lactam-β-lactamase inhibitor combinations and cephalosporins. At onset of candidemia, a significantly lower number of IMW patients were mechanically ventilated (p<0.01); these patients did not have central line catheters comparable to ICU and surgical patients (p<0.001). They were less likely to receive adequate antifungal therapy within 48h, and this was the only significant predictor of survival in these patients (p=0.028): hazard ratio 3.7 (95% confidence interval 1.14-12.5) for therapy delayed to >48h.

CONCLUSIONS

IMW candidemic patients account for a substantial proportion of candidemia cases and have unique characteristics and high mortality rates.

Outcome of Candida Parapsilosis Complex Infections Treated with Caspofungin in Children

BACKGROUND

We aimed to evaluate the correlation of caspofungin E-tests with the prognosis and response to caspofungin therapy of Candida parapsilosis complex bloodstream infections in children hospitalized in a pediatric intensive care unit.

METHODS

All children who had C. parapsilosis complex bloodstream infections and who were treated with caspofungin were included in this retrospective study. For each patient, the following parameters, including all consecutive blood and central venous catheter (CVC) cultures, the duration between diagnosis and CVC removal, mortality rate, relapses of the C. parapsilosis complex infections as well as the demographic features, were recorded.

RESULTS

The central venous catheter survival rate was 33.3% under caspofungin treatment. In 92.4 % of the patients, the negative culture was achieved within a median duration of 12.5 days. The rate of relapses was 18.9%. The overall mortality rate was 37.7% (20 of 53 patients), and the 30-days mortality rate was 7.5% (4 of 53 patients). There was no statistically significant difference between the groups with MIC<2 mg/l and MIC =2 mg/l using CVC survival rate; rate and duration of achieving negative blood culture for C. parapsilosis complex; duration of hospital stay; rate and duration of relapses; overall mortality and 30-days mortality.

CONCLUSIONS

The beneficial effects of Caspofungin on biofilms has been shown in vivo, while its impact in children for maintenance of CVC was limited in our study but should not be underestimated in children who strongly need the presence of CVCs. The clinicians should weigh their priority for their patients and choose the optimal antifungal therapy for C. parapsilosis complex infections in children.

Molecular study of the Candida parapsilosis complex in Sfax, Tunisia

Candida parapsilosis, which was previously considered to be a complex of three genetically distinct groups, has emerged as a significant agent of nosocomial infections. Recently, this complex was separated into three species: C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis In Tunisia, data pertaining to these fungi are limited. Thus, the purpose of our study was to determine by BanI PCR-RFLP and ITS sequencing, the occurrence of Candida parapsilosis complex among 182 isolates identified as C. parapsilosis by phenotypical methods. C. parapsilosis sensu stricto represented 94.5% of all isolates, while C. metapsilosis and. C. orthopsilosis were identified in 3.3% and 2.2%, respectively. Sequence analysis of internal transcribed spacer region confirmed and revealed only one genotype among the C. parapsilosis sensu stricto strains, three genotypes among six C. metapsilosis strains and two genotypes among four C. orthopsilosis strains.