Epidemiology of Invasive Candidiasis in Patients with Hematologic Malignancy on Antifungal Prophylaxis

The landscape of invasive Candida infections in patients with hematologic malignancy has evolved due to the adoption of anti-fungal prophylaxis, advances in oncological therapies, and developments in antifungal therapies and diagnostics. Despite these scientific gains, the morbidity and mortality caused by these infections remain unchanged, highlighting the importance of an updated understanding of its epidemiology. Non-albicans Candida species are now the predominant cause of invasive candidiasis in patients with hematological malignancy. This epidemiological shift from Candida albicans to non-albicans Candida species is partially a consequence of selective pressure from extensive azole use. Further analysis of this trend suggests other contributing factors including immunocompromise caused by the underlying hematologic malignancy and the intensity of its associated treatments, oncological practices, and regional or institution specific variables. This review characterizes the changing distribution of Candida species in patients with hematologic malignancy, describes the causes driving this change, and discusses clinical considerations to optimize management in this high-risk patient population.

Candidiasis and Other Emerging Yeasts

Purpose of Review

The review presents a comprehensive and updated information on the contemporary status of invasive candidiasis (IC), other emerging yeast infections, and the challenges they present in terms of at-risk population, specific virulence attributes, and antifungal susceptibility profile.

Recent Findings

With the advancement in medical field, there has been parallel expansion of vulnerable populations over the past two decades. This had led to the emergence of a variety of rare yeasts in healthcare settings, both Candida and non-Candida yeast causing sporadic cases and outbreaks. The advancements in diagnostic modalities have enabled accurate identification of rare Candida species and non-Candida yeast (NCY) of clinical importance. Their distribution and susceptibility profile vary across different geographical regions, thus necessitating surveillance of local epidemiology of these infections to improve patient outcomes.

Summary

The challenges in management of IC have been complicated with emergence of newer species and resistance traits. C. tropicalis has already overtaken C. albicans in many Asian ICUs, while C. auris is rising rapidly worldwide. Recent genomic research has reclassified several yeasts into newer genera, and an updated version of MALDI-TOF MS or ITS sequencing is necessary for accurate identification. Having a knowledge of the differences in predisposing factors, epidemiology and susceptibility profile of already established pathogenic yeasts, as well as new emerging yeasts, are imperative for better patient management.

Prevalence and species distribution of Candida bloodstream infection in children and adults in two teaching university hospitals in Egypt: first report of Candida kefyr

BACKGROUND

Candidemia is a pervasive problem associated with significant morbidity and mortality in health care settings. This study aimed to determine the changing distribution of Candida species and the emergence of uncommon species.

METHODS

This was a cross-sectional study performed in two Cairo University hospitals between 2019 and 2020. All Candida species isolates recovered from blood cultures of adults and pediatrics patients admitted to the hospitals were included. Candida isolates were identified by chromogenic Candida agar and Vitek2 YST identification card. Candida kefyr was confirmed by chip array.

RESULTS

Candida species were responsible for 1.6% of bloodstream infections in adults and 10.8% in pediatric patients. C. albicans was the most prevalent species representing 27.8% in adults and 48.3% in pediatrics. Non-albicans species (NAC) represented the most isolated Candida species among adults and pediatrics (72.2% and 51.6%, respectively) with the predominance of C. tropicalis (27.8% and 22.5%, respectively) followed by C. parapsilosis (16.7% and 10.8%, respectively). The uncommon Candida, which is Candida species other than C. albicans, C. parapsilosis, C. tropicalis, C. glabrata, and C. krusei, represents 16.6% and 14% of all candidemia in adults and pediatrics, respectively. Only one of each of C. lusitaniae, C. utilis, and C. kefyr were detected in adults. C. lusitaniae was the most frequently recovered uncommon Candida among pediatrics resulting in 6.4% of candidemia followed by C. famata (4.3%), C. utilis (2.2%), and C. kefyr (1.1%).

CONCLUSIONS

C. albicans is still the primary species isolated from pediatrics and adults with candidemia despite the considerable shift to the non-albicans species. C. tropicalis and C. parapsilosis are the most prevalent NAC. The increased prevalence of uncommon Candida species is alarming and necessitates a prompt stewardship program.

Epidemiology of candidemia in NICE area, France: A five-year study of antifungal susceptibility and mortality

OBJECTIVES

The aim of this study was to investigate the epidemiology of candidemia, the fungal susceptibility, the first-line therapy and the morality rate over 5 years. Knowing the differences of the yeasts in the candidemia local epidemiology, is essential to obtain information on fungal epidemiology to adapt antifungal strategies.

MATERIALS/METHODS

This retrospective study was conducted from January 2014 to December 2018. The susceptibility of the Candida strains were tested for amphotericin B, caspofungin, voriconazole and fluconazole.

RESULTS

The 304 strains were isolated from 290 patients (40 patients in 2014, 65 in 2015, 72 in 2016, 62 in 2017 and 51 in 2018). The three most common Candida spp isolated from blood cultures were Candida albicans (44%), Candida glabrata (22%) and Candida parapsilosis (13%). The proportion of non-albicans Candida decreased from 68% in 2014 to 45% in 2018. C. albicans and C. parapsilosis were to the four antifungals tested. As first-line therapy, 60% of patients received caspofungin and 26% fluconazole. There was no significant difference in the mortality between the two arms of patients (, 27% and 21%, p = 0.47 at 30 days respectively). Thirty day all-cause mortality was 31% and it decreased from 2014 (46%) to 2018 (18%).

CONCLUSIONS

We report that the absence of antifungal resistance of our C. albicans and C. parapsilosis candidemia suggests possible treatment after MALDI-TOF identification with fluconazole as first-line therapy in our hospital, as soon as possible and while continuing to perform the antifungal test.

Comparative evaluation of the Bruker Biotyper and Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems for non-albicans Candida and uncommon yeast isolates

INTRODUCTION

Rapid and accurate diagnosis is critically important in invasive and disseminated fungal infections for appropriate antifungal treatment.

HYPOTHESIS

MALDI-TOF MS systems are effective for fast and accurate identification of Candida species.

AIM

We aimed to compare two MALDI-TOF MS systems for the rapid identification of non-albicans Candida and rare clinical yeast species.

METHODOLOGY

This study included 157 isolates representing 23 yeast species. All isolates were identified using Bruker MALDI Biotyper and VITEK MS systems. If both MALDI-TOF MS systems yielded the same results for a certain isolate, the identification is regarded as correct. We performed internal transcribed spacer (ITS) DNA sequencing on five fungal isolates with discordant species names or that were unidentified by the two MALDI-TOF MS systems.

RESULTS

The yeast identification sensitivity of MALDI Biotyper was 98.7%, whereas that of VITEK MS was 96.8%. Both MALDI-TOF MS systems correctly identified all strains belonging to four prevalent species, namely, Candida parapsilosis, Candida tropicalis, Candida glabrata, and Candida krusei. For the 19 rare clinical yeast species, identification rates were 96.7% for MALDI Biotyper and 91.7% for VITEK MS. The ITS sequence analysis of five isolates yielded two Meyerozyma caribbica, two Cyberlindnera fabianii, and one Candida dubliniensis.

CONCLUSIONS

This study showed the high performance of both MALDI-TOF MS systems, identifying over 90% of yeast isolates in a short time. The disadvantages of these systems are that some species are not present in the databases and it cannot distinguish closely related species. The sensitivity of MALDI-TOF MS systems constantly improves with the expansion of databases in parallel with taxonomic developments for the identification of rare clinical yeast species.

Candida spp bloodstream infections in a Latin American Pediatric Oncology Reference Center: Epidemiology and associated factors

BACKGROUND

Invasive fungal disease is a significant cause of morbidity and mortality in immunosuppressed children. The recognition of patients at risk for candidaemia is paramount to a better prognosis.

OBJECTIVES

To characterize Candida spp bloodstream infections (BSI) in a reference centre for paediatric oncology and to describe the most prevalent risk factors associated with candida infections.

PATIENTS/METHODS

This is a retrospective cohort study carried out with paediatric patients followed up with at the Institute of Pediatric Oncology, Brazil, who presented positive blood culture for Candida spp from January 2004 to December 2016.

RESULTS

Ninety episodes of candidaemia were analysed; patients had a median age of 4.5 years, and 57.8% were males, with a diagnosis of solid tumours in 54.5% of cases. The most common Candida species were C albicans (35.6%), C parapsilosis (30.0%) and C tropicalis (16.7%). C tropicalis BSI was associated with neutropenia and skin lesions. Therapy was successful in 67.1% of the episodes. Older age and thrombocytopenia were associated with therapeutic failure. Death within 30 days occurred in 24.4% of patients; predictive factors were older age and admission to an ICU C parapsilosis candidaemia was a protective factor for death when compared to C albicans.

CONCLUSION

The main species isolated were C albicans, C parapsilosis and C tropicalis. C tropicalis BSI was associated with neutropenia and skin lesions. The death rate was significant, and a worse prognosis was associated with older age, thrombocytopenia and admission to an ICU C parapsilosis infection proved to be a protective factor against mortality.

Prevalence of vulvovaginal candidiasis among pregnant women in the Ho municipality, Ghana: species identification and antifungal susceptibility of Candida isolates

Background

Candida is the leading cause of vaginitis, and 75% of women have at least one episode of infection in their lives, with pregnancy being a predisposing factor. If left untreated, vulvovaginal candidiasis (VVC) can lead to chorioamnionitis with subsequent abortion, prematurity and congenital infection of the neonate. We aimed to determine the prevalence of VVC, identify the recent and most frequently occurring species of Candida in pregnant women, and determine the most effective antifungal drug of choice for treatment.

Method

A prospective cross-sectional study in which 176 high vaginal swab samples of consented pregnant women visiting the antenatal clinic from February 2018 to April 2018 were subjected to direct gram smear and culture for Candida isolation. Candida isolates were identified using a germ tube test and HiCrome Candida differential agar. Candida isolates were then subjected to a disk diffusion method using fluconazole (25 μg), nystatin (100 units), and voriconazole (1 μg) on Mueller-Hinton agar supplemented with 2% (w/v) glucose and 0.5 μg/ml methylene blue dye to determine the susceptibility pattern as per the guidelines of the Clinical Laboratory Standard Institute (CLSI). Chi-square analysis was used to ascertain the significant association of participants’ sociodemographics and clinical presentations to VVC. A univariate logistic regression model was used to identify potential risk factors of VVC.

Results

The prevalence of VVC among our study participants was 30.7%. Non-albicans Candida (NAC) and Candida albicans had a prevalence of 74.1 and 25.9%, respectively. Candida glabrata was the most common species, followed by Candida albicans, Candida krusei, and Candida parapsilosis. 50.0, 18.5 and 3.7% of Candida species were susceptible to voriconazole, fluconazole and nystatin, respectively, whereas 37.0, 48.1 and 9.3% of Candida species were resistant to voriconazole, fluconazole and nystatin, respectively. The majority of isolates were susceptible dose dependent to all three antifungal agents, with voriconazole being the most efficacious antifungal agent. There was no significant association between participants’ socio-demographic information and clinical presentations to VVC.

Conclusion

The prevalence of VVC was high in the study area. C. glabrata was found to be the most common cause of VVC among the pregnant women attending antenatal clinics, in the Ho Municipality region of Ghana. The majority of the Candida isolates were susceptible and resistant to voriconazole and fluconazole, respectively.

Anti-fungal susceptibility and virulence factors of Candida spp. isolated from blood cultures

Candidemia is one of the most common fungal nosocomial infections worldwide. It causes high mortality and morbidity rate with significant hospital costs due to increased length of hospital stay and costs for anti-fungal treatment. This study aims to investigate anti-fungal drug susceptibility, enzymatic activity and biofilm formation of the Candida spp. isolated from blood cultures. In 2016, a total of 84 clinical Candida isolates were analyzed for minimum inhibitory concentration (MIC) against fluconazole and amphotericin B by agar diffusion E-test (E-strips). Three enzymatic activity tests for phospholipase, proteinase and esterase were performed by using egg yolk agar, bovine serum albumin medium and Tween 80 opacity medium, respectively. Biofilm formation was determined by crystal violet staining. To describing the various Candida distributions cultured, C. albicans was the most frequent species (n=37, 44.1%), followed by C. tropicalis (n=30, 35.7%), C. parapsilosis (n=8, 9.5%), C. glabrata (n=6, 7.1%) and C. guilliermondii (n=3, 3.6%). Regarding anti-fungal drug susceptibility, C. albicans was susceptible to fluconazole (100%). In addition, all clinical Candida isolates were fully susceptible to amphotericin B (100%). The predominant enzyme activity of C. albicans included medium to high levels of phospholipase, proteinase and esterase activities. C. tropicalis displayed esterase activity, while C. glabrata and C. guilliermondii had no phospholipase and proteinase activity. Non-albicans Candida (NAC) i.e. C. tropicalis formed a biofilm at a higher rate than C. albicans. This study revealed the production of virulent factors in Candida strains from candidemia patients.

N,N'-diaryl-bishydrazones in a biphenyl platform: Broad spectrum antifungal agents

N,N'-Diaryl-bishydrazones of [1,1'-biphenyl]-3,4'-dicarboxaldehyde, [1,1'-biphenyl]-4,4'-dicarboxaldehyde, and 4,4'-bisacetyl-1,1-biphenyl exhibited excellent antifungal activity against a broad spectrum of filamentous and non-filamentous fungi. These N,N'-diaryl-bishydrazones displayed no antibacterial activity in contrast to previously reported N,N'-diamidino-bishydrazones and N-amidino-N'-aryl-bishydrazones. The leading candidate, 4,4'-bis((E)-1-(2-(4-fluorophenyl)hydrazono)ethyl)-1,1'-biphenyl, displayed less hemolysis of murine red blood cells at concentrations at or below that of a control antifungal agent (voriconazole), was fungistatic in a time-kill study, and possessed no mammalian cytotoxicity and no toxicity with respect to hERG inhibition.

Correlation between antifungal consumption and the distribution of Candida species in different hospital departments of a Lebanese medical Centre

Background

In recent years, there has been a significant increase in the incidence of fungal infections attributed to Candida species worldwide, with a major shift toward non-albicans Candida (NAC). In this study, we have described the distribution of Candida species among different hospital departments and calculated the antifungal consumption in our facility. We also correlated the consumption of certain antifungals and the prevalence of specific Candida species.

Methods

This was a retrospective review of all the Candida isolates recovered from the computerised microbiology laboratory database of Makassed General Hospital, a tertiary care centre in Beirut, Lebanon, between January 2010 and December 2015. Data on antifungal consumption between January 2008 and December 2015 were extracted from the hospital pharmacy electronic database. We used Spearman’s coefficient to find a correlation between Candida species distribution and antifungal consumption.

Results

Between 2008 and 2015, we observed that the highest antifungal consumption was in the haematology/oncology department (days of therapy/1000 patient days = 348.12 ± 85.41), and the lowest was in the obstetrics/gynaecology department (1.36 ± 0.47). In general, the difference in antifungal consumption among various departments was statistically significant (P < 0.0001). Overall, azoles were the most common first-line antifungals in our hospital. Echinocandins and amphotericin B were mostly prescribed in the haematology/oncology department. As for Candida species distribution, a total of 1377 non-duplicate isolates were identified between 2010 and 2015. A non-homologous distribution of albicans vs. non-albicans was noted among the different departments (P = 0.02). The most commonly isolated NAC was Candida glabrata, representing 14% of total Candida species and 59% of NAC. Candida famata (9% of NAC), Candida parapsilosis (3.6% of NAC) and Candida krusei (3% of NAC) were recovered unequally from the different departments. The total antifungal consumption correlated positively with the emergence of NAC. The use of azoles correlated positively with Candida glabrata, while amphotericin B formulations correlated negatively with it. None of these correlations reached statistical significance.

Conclusion

Different Candida species were unequally distributed among different hospital departments, and this correlated with consumption of antifungals in respective departments, highlighting the need for antifungal stewardship.

Proteolytic activity of non-albicans Candida and Candida albicans in oral cancer patients

Oral Candida infections can be life-threatening in medically compromised patients. In particular non-albicans Candida strains are virulent. However, our knowledge is sparse on how proteolytic these strains are in patients with oral cancer. Our study aimed to investigate differences in proteolytic activity of non-albicans Candida and Candida albicans isolated from oral cancer patients. The hypothesis was based on anticipated different invasive capacity of the strains. Clinical and reference yeast samples from our laboratory were used for analyses. Candida strains were grown in yeast peptone glucose and the activity of Candida proteinases of broken cell fractions were analysed by MDPF-gelatin zymography. Fluorometric assay was used to compare activities of proteolytic enzymes and degradation assays were performed using CLDN 4 and plasma fibronectin. Clear differences were seen in the proteolytic activity between the studied non-albicans Candida and C. albicans strains. C. tropicalis had the highest proteolytic activity followed by strains of C. krusei and C. glabrata. The results confirmed our study hypothesis by showing differences between the non-albicans Candida and Candida albicans strains studied. Higher proteolytic activity may thus have an effect on the virulence of non-albicans Candida strains in oral cancer patients.

Activity of Diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside, its Hydrochloride, and N,N-dialkyl Derivatives Against Non-albicans Candida Isolates

BACKGROUND

Candida albicans belongs to the most common fungal pathogens in humans, but recently an increased proliferation of strains called non-albicans Candida has been reported. Species belonging to this group are often characterised by a reduced susceptibility to antifungal agents.

OBJECTIVE

In view of the emergence of non-albicans Candida and their resistance to available antifungals, an attempt has been made to develop novel effective agents. Biological activities of the N,N-dialkyl diosgenyl glycosides, which were previously synthesized, were determined.

METHOD

Minimum inhibitory concentration (MIC) was determined for group of clinical nonalbicans Candida isolates by serial dilution method in Sabouraud liquid medium. In order to assess the toxicity towards human cells the minimum haemolytic concentration (MHC) was determined on human erythrocytes by serial dilution method in phosphoric buffer.

RESULTS

The saponins exhibited a strong activity towards clinical isolates of C. glabrata and C. parapsilosis comparable or even stronger than that of conventional antimicrobials. A high rate of resistance to fluconazole was shown among C. glabrata isolates. Among clinical strains of C. krusei and C. tropicalis, isolates with a decreased susceptibility to saponins were identified. All the tested C. krusei isolates showed resistance to fluconazole, while among C. tropicalis numerous strains were resistant to all tested azoles. The saponins did not show haemolytic activities at their microbiologically active concentrations.

CONCLUSION

Results of the present work encourage to continue the study on steroidal saponins and their potential application for the treatment of candidemia.

Comparative Study of the Effects of Fluconazole and Voriconazole on Candida glabrata, Candida parapsilosis and Candida rugosa Biofilms

Infections by non-albicans Candida species are a life-threatening condition, and formation of biofilms can lead to treatment failure in a clinical setting. This study was aimed to demonstrate the in vitro antibiofilm activity of fluconazole (FLU) and voriconazole (VOR) against C. glabrata, C. parapsilosis and C. rugosa with diverse antifungal susceptibilities to FLU and VOR. The antibiofilm activities of FLU and VOR in the form of suspension as well as pre-coatings were assessed by XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction assay. Morphological and intracellular changes exerted by the antifungal drugs on Candida cells were examined by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results of the antibiofilm activities showed that FLU drug suspension was capable of killing C. parapsilosis and C. rugosa at minimum inhibitory concentrations (MICs) of 4× MIC FLU and 256× MIC FLU, respectively. While VOR MICs ranging from 2× to 32× were capable of killing the biofilms of all Candida spp tested. The antibiofilm activities of pre-coated FLU were able to kill the biofilms at ¼× MIC FLU and ½× MIC FLU for C. parapsilosis and C. rugosa strains, respectively. While pre-coated VOR was able to kill the biofilms, all three Candida sp at ½× MIC VOR. SEM and TEM examinations showed that FLU and VOR treatments exerted significant impact on Candida cell with various degrees of morphological changes. In conclusion, a fourfold reduction in MIC₅₀ of FLU and VOR towards ATCC strains of C. glabrata, C. rugosa and C. rugosa clinical strain was observed in this study.

Epidemiology and antifungal susceptibility of Candida species in a tertiary care hospital, Kolkata, India

Background and Purpose:

The incidence of fungal infection as well as candidemia has increased significantly, contributing to morbidity and mortality in the developed countries. The alarming increase in infections with multidrug resistant bacteria is due to overuse of a broad spectrum antimicrobials, which leads to over growth of Candida spp.; thus, enhancing its opportunity to cause the disease. A shift has been observed in the relative frequency of each Candida spp. Antifungal agents available for the treatment of systemic and invasive candidiasis are restricted to polyenes, allylamines, azoles, and the recent echinocandin class of molecules. In the past few decades, the incidence of resistance to antifungal treatment of Candida spp. has increased rapidly, which is of serious concern for healthcare professionals. Studies on prevalence of infections and antifungal susceptibility testing can help with deciding on clinical strategies to manage this problem. Herein, we aimed to identify the epidemiology of Candida spp. among blood culture isolates and to investigate the susceptibility pattern of these species to antifungal agents.

Materials and Methods:

Candida spp. were isolated from blood cultures from 70 patients in a tertiary care hospital, Kolkata, India. The growth of Candida spp. on sabouraud dextrose agar was confirmed by Gram staining, where gram-positive budding fungal cells were observed. The species identification as well as antifungal susceptibility testing were performed with VITEK 2 compact automated system using VITEK-2 cards for identification of yeast and yeast-like organisms) ID-YST card). Antifungal susceptibility testing was carried out with VITEK 2 fungal susceptibility card (AST-YS07 kit).

Results:

Out of 70 samples, Candidaalbicans were isolated from 34 (%48.57) samples. The remaining 36 (%51.43) were non-albicans Candida ) NAC). Out of 34 C. Albicans, antifungal susceptiblity was detected in 28 isolates, all of which were sensitive to fluconazole (FLC .( Resistance to amphotericine B) AMP), flucytosine (5FC), voriconazole (VRC), and itraconazole (ITC) was observed in, %44.12 , %52.94 , %8.82 and %17.65 of the cases, respectively. For other Candida spp. (other than C. Albicans ,( antifungal susceptibility was evaluated for 36 isolates, among which resistance to AMP, FLC , 5FC, VRC , and ITC was found in, %30.56 , %61.11 , %33.33 , %19.44 and %38.89 cases, respectively.

Conclusion:

Species-level identification of Candida and their antifungal sensitivity testing should to be performed to achieve better clinical result and to select an appropriate and effective antifungal therapy. High resistance to antifungal agents is an alarming sign to the healthcare professionals.

High Recovery Rate of Non-albicans Candida Species Isolated From Burn Patients With Candidemia in Iran

Background:

Blood stream infections (BSIs) are major causes of morbidity and mortality in burn patients. Microorganisms responsible for BSI are generally bacteria; however, Candida spp. are the infection agents in as many as 8% of all cases. Burn wound colonization and infections are generally the first steps to systemic infection. Candidemia in burn patients has been associated with high mortality and a prolonged hospital stay.

Objectives:

Candidemia in burn patients has been defined as a preterminal event, leading to high morbidity and mortality rates among these patients. The aim of this study was to establish the incidence of candidemia in burn patients in Iran.

Patients and Methods:

We consecutively collected 405 blood samples from 113 burn patients. The yeast isolates were identified to the species level using conventional procedures. In vitro antifungal susceptibility of the Candida isolates to amphotericin B, fluconazole, voriconazole and caspofungin was performed using the Etest.

Results:

Twenty-seven samples (6.7%) of the blood cultures from 13 patients (12%) were positive for Candida species. Candidaparapsilosis (38%) and C. tropicalis (38%) were the most commonly found Candida species, followed by C. albicans (15%) and C. guilliermondii (15%) in the patients. The incidence of candidemia was significantly correlated with increased duration of hospitalization, increased time of stay in the intensive care unit, and higher mortality. The antifungal susceptibility tests demonstrated that amphotericin B and voriconazole had the lowest minimum inhibitory concentrations (MICs) against Candida spp.

Conclusions:

Non-albicans Candida should be considered as significant pathogens in burned patients with candidemia.

Distribution of Candida species isolated from blood cultures in hospitals in Osaka, Japan

BACKGROUND

Candida species are clinically important causes of bloodstream infections because their mortality is very high. Given that some species of Candida are azole-resistant, identifying the distributions of Candida species could facilitate the formulation of an appropriate empirical antifungal therapy. It has been shown that the distribution varies depending on the continent, country, city, and hospital. In this paper, we describe the distributions of species in hospitals in northern Osaka, Japan.

METHOD

We evaluated blood culture results obtained from six tertiary hospitals in the northern Osaka area between 2004 and 2011. We also obtained comorbidity information from the patients' hospital medical records. Kaplan-Meier curves were drawn to compare the risk of death related to the different species.

RESULTS

Of the 165 cases of candidemia confirmed by blood culture, 66% were male and the mean age was 62 years (range = 0-96). Overall, Candida albicans comprised 70 cases (43%), followed by Candida parapsilosis with 36 cases (22%), Candida glabrata with 25 cases (15%), Candida tropicalis with 11 cases (7%), Candida krusei with 10 cases (6%), and other Candida species with 13 cases (8%). C. tropicalis had higher associated mortality than other species, although it was not statistically significant.

CONCLUSIONS

C. albicans was the most frequently isolated species, but the proportion of non-albicans Candida species was not negligible. The relatively high frequency of non-albicans Candida species distinguished the Japanese distribution from other areas. This characteristic distribution may have important implications when formulating an empirical antifungal therapy for Japanese clinical practice.

Regional data analysis of Candida non-albicans strains collected in United States medical sites over a 6-year period, 2006-2011

Limited data are available on temporal and geographic variation of occurrence and antifungal resistance of non-C. albicans Candida species (non-CA-CSP) from the USA. The objective of this study was to evaluate the occurrence and antifungal resistance of 1694 isolates of non-CA-CSP collected during the period 2006-2011. Isolates were recovered in 33 hospitals located in four regions: Northcentral, North-east, South-east and West and tested using CLSI reference broth microdilution methods. Non-CA-CSP represented 55.6% of all Candida. C. glabrata was most predominant (39-42% of non-CA-CSP). Infections due to C. glabrata, C. krusei and C. dubliniensis increased over the 6 years. Anidulafungin (3.6%) and caspofungin (5.7%) resistance were prominent among C. glabrata from the North-east and West regions respectively. Resistance to micafungin was detected in 2.0% and 2.9% of C. glabrata from the West and North-east regions respectively. Echinocandin resistance was low, except for C. dubliniensis. Azole resistance was most prominent among C. glabrata from the South-east (13.6% fluconazole R) and the West (18.0%). Cross-resistance among three tested azoles was observed in C. glabrata from all regions. Whereas differences in species distribution and antifungal R varied across geographic regions, there was little evidence of temporal increase in resistance to azoles or echinocandins in the monitored non-CA-CSP.

Recent Taxonomic Developments with Candida and Other Opportunistic Yeasts

Increases in susceptible patient populations and advances in identification methods have resulted in the continued recognition of novel yeasts as agents of human infection. Most of these agents are members of the well-recognized genera Candida, Cryptococcus, Trichosporon, and Rhodotorula. Some of these agents are "cryptic species," members of species complexes, and may not be detectable using classical carbohydrate assimilation-based methods of yeast identification. Such species require DNA- or MALDI-based methods for correct identification, although sporadic isolates may not routinely require delineation to the individual species level. The coming end of the fungal taxonomy rules requiring separate names for sexual and asexual forms of the same fungus will hopefully allow greater clarity, as names for medically important yeast can now be based on the needs of the medical mycology community and the common goal of better communication between laboratory and clinician.