Emergence of Candida parapsilosis as the predominant species causing candidemia in children

Genotypic Diversity of Candida parapsilosis Complex in Invasive Candidiasis at a Pediatric Tertiary Hospital: A 5-Year Retrospective Study

Invasive candidiasis (IC) contributes to the morbidity and mortality of hospitalized patients and represents a significant burden to the healthcare system. Previous Brazilian studies have reported the presence of endemic Candida parapsilosis sensu stricto genotypes causing candidemia and clonal transmission involving fluconazole-resistant isolates. We performed a 5-year retrospective analysis of IC cases in a Brazilian tertiary pediatric hospital and conducted a molecular investigation of C. parapsilosis sensu stricto. Non-duplicate C. parapsilosis sensu stricto genotyping was performed by microsatellite analysis. Antifungal susceptibility and biofilm formation were also evaluated. A total of 123 IC episodes were identified, with an IC incidence of 1.24 cases per 1000 hospital admissions and an overall mortality of 34%. The main species were the C. parapsilosis complex (35.8%), Candida albicans (29.2%), and Candida tropicalis (21.9%). All C. parapsilosis sensu stricto were recovered from blood cultures, and 97.5% were biofilm producers. Microsatellite typing identified high genotypic diversity among the isolates. We observed that all isolates were sensitive to amphotericin B, and although one isolate was non-sensitive to fluconazole, only a silent mutation on ERG11 gene was identified. No clear evidence of clonal outbreak or emergence of fluconazole-resistant isolates was found, suggesting that multiple sources may be involved in the epidemiology of IC in children.

Continuing Shifts in Epidemiology and Antifungal Susceptibility Highlight the Need for Improved Disease Management of Invasive Candidiasis

Invasive candidiasis (IC) is a systemic life-threatening infection of immunocompromised humans, but remains a relatively neglected disease among public health authorities. Ongoing assessments of disease epidemiology are needed to identify and map trends of importance that may necessitate improvements in disease management and patient care. Well-established incidence increases, largely due to expanding populations of patients with pre-disposing risk factors, has led to increased clinical use and pressures on antifungal drugs. This has been exacerbated by a lack of fast, accurate diagnostics that have led treatment guidelines to often recommend preventative strategies in the absence of proven infection, resulting in unnecessary antifungal use in many instances. The consequences of this are multifactorial, but a contribution to emerging drug resistance is of primary concern, with high levels of antifungal use heavily implicated in global shifts to more resistant Candida strains. Preserving and expanding the utility and number of antifungals should therefore be of the highest priority. This may be achievable through the development and use of biomarker tests, bringing about a new era in improved antifungal stewardship, as well as novel antifungals that offer favorable profiles by targeting Candida pathogenesis mechanisms over cell viability.

Characteristics, Risk Factors and Predictors for Candidemia in the Pediatric Intensive Care Unit at the University Hospital Centre Zagreb in Croatia: A 9-Year Retrospective Study

BACKGROUND

Candidemia is one of the leading causes of bloodstream infections in the pediatric intensive care unit (PICU). The aim of this study was to define characteristics and risk factors for candidemia in the PICU setting and propose a predictive model to identify the patients at risk.

METHODS

This was a retrospective matched case-control study in the PICU during a 9-year period. Patients with candidemia were studied and matched with control patients without candidemia. Univariate analysis was performed for potential risk factors and multivariate analysis was conducted to determine the prediction score for candidemia.

RESULTS

Forty-two cases of candidemia were matched with 84 control patients. Candida parapsilosis was the most common (71.4%) species. Risk factors independently associated with candidemia were: the use of >2 antibiotics in a maximum period of 4 weeks before the candidemia (odds ratio [OR]: 10.59; 95% confidence interval [CI]: 2.05-54.83), a previous bacterial infection in a maximum period of 4 weeks before the candidemia (OR: 5.56; 95% CI: 1.44-21.5) and the duration of PICU stay of >10 days (OR: 4.22; 95% CI: 1.02-17.41). The proposed predictive scoring system has a sensitivity of 95.24%, specificity of 76.12%, OR 64.0, 95% CI 14.2-288.6, the positive predictive value of 66.67% and the negative predictive value of 96.97%.

CONCLUSIONS

Previously reported risk factors for candidemia have been confirmed and some new have been detected. The presented scoring system can help identify patients who would benefit from prophylactic antifungal therapy.

Clinical efficacy and safety of antifungal drugs for the treatment of Candida parapsilosis infections: a systematic review and network meta-analysis

Antifungal drugs have already been established as an effective treatment option for Candida parapsilosis infections, but there is no universal consensus on the ideal target for clinical efficacy and safety of antifungal drugs for the treatment of C. parapsilosis infections. Few studies have directly compared the efficacies of antifungal drugs for the treatment of C. parapsilosis infections. We hypothesize that different antifungal drugs offer differing clinical efficacy and safety for the treatment of C. parapsilosis infections. We performed a comprehensive network meta-analysis on different strategies for C. parapsilosis infection treatment and compared the clinical efficacy and safety of antifungal drugs as interventions for C. parapsilosis infections. The Cochrane Database of Systematic Reviews, Medline, Embase, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Technology of Chongqing VIP database, Wan Fang Data, and SinoMed databases were searched to identify appropriate randomized trials. Among the extracted C. parapsilosis cases, the survival and death rates with treatment of C. parapsilosis infection were compared among groups treated with different antifungal drugs. According to the evidence-network analysis, echinocandins were a better choice than other drugs for treating C. parapsilosis infections, and more importantly, caspofungin showed a more preferable effect for decreasing the risk of 30 day mortality. In conclusion, this study systematically evaluated the effectiveness and safety of antifungal drugs for the purpose of helping clinicians choose the most appropriate antifungal drugs. Future studies with larger samples are needed to evaluate the effects of patient factors on the clinical efficacy and safety of antifungal drugs for C. parapsilosis infections.

Enhancing the chemical transformation of Candida parapsilosis

Candida parapsilosis is a leading cause of invasive mycoses and the major cause of nosocomial fungaemia amongst low and very low birth weight neonates. However, the molecular and physiological characteristics of this fungus remain understudied. To advance our knowledge about the pathobiology of this pathogen, we sought to develop and validate an effective method for chemical transformation of C. parapsilosis. Chemical transformation is the primary procedure for introducing foreign DNA into Candida yeast as it requires no special equipment, although its performance efficacy drops rapidly when the size of the transforming DNA increases. To define optimal conditions for chemical transformation in C. parapsilosis, we selected a leucine auxotroph laboratory strain. We identified optimal cell density for transformation, incubation times, inclusion of specific enhancing chemicals, and size and amounts of DNA fragments that resulted in maximized transformation efficiency. We determined that the inclusion of dimethyl sulfoxide was beneficial, but dithiothreitol pretreatment reduced colony recovery. As a result, the modified protocol led to a 20–55-fold increase in transformation efficiency, depending on the size of the transforming fragment. We validated the modified methodology with prototrophic isolates and demonstrated that the new approach resulted in the recovery of significantly more transformants in 5 of 6 isolates. Additionally, we identified a medium in which transformation competent yeast cells could safely be maintained at −80°C for up to 6 weeks that reduces laboratory work and shortens the overall procedure. These modifications will significantly aid further investigations into the genetic basis for virulence in C. parapsilosis.

Association of different Candida species with catheter-related candidemia, and the potential antifungal treatments against their adhesion properties and biofilm-forming capabilities

Background

To compare the adhesion properties and biofilm‐forming capabilities of 27 Candida isolates obtained from catheter‐related candidemia patients and to evaluate the inhibitory effects of antifungal agents on different Candida species.

Material and Methods

Seven C. albicans, six C. parapsilosis, five C. guilliermondii, five C. tropicalis, and four C. glabrata clinical isolates were investigated. We quantified the adherence of these Candida species by flow cytometric method and evaluated the formation of biofilms by XTT reduction and crystal violet methods. Actions of micafungin (MF), fluconazole (FZ), and N‐acetylcysteine (NAC) on the adhesion and biofilm formation of different Candida species were determined.

Results

Non‐albicans Candida species were demonstrated to have stronger adhesion abilities compared with C. albicans. The biofilm‐forming capabilities of different Candida species were varied considerably, and the degree of biofilm formation might be affected by different assay approaches. Interestingly, C. parapsilosis displayed the highest biofilm formation abilities, while C. glabrata exhibited the lowest total biomass and metabolic activity. Furthermore, the inhibitory activities of MF, FZ, and NAC on fungal adhesion and biofilm formation were evaluated, and the results indicated that MF could reduce the adhesion ability and biofilm metabolism more significantly (p < 0.05), and its antifungal activity was elevated in a dose‐dependent manner.

Conclusion

Non‐albicans Candida species, especially C. guilliermondii, C. tropicalis, and C. parapsilosis, exhibited higher adhesion ability in catheter‐related candidemia patients. However, these Candida species had varied biofilm‐forming capabilities. MF tended to have stronger inhibitory effects against both adhesion and biofilm formation of different Candida species.

Trends in Pediatric Candidemia: Epidemiology, Anti-Fungal Susceptibility, and Patient Characteristics in a Children's Hospital

Candida bloodstream infections (CBSIs) have decreased among pediatric populations in the United States, but remain an important cause of morbidity and mortality. Species distributions and susceptibility patterns of CBSI isolates diverge widely between children and adults. The awareness of these patterns can inform clinical decision-making for empiric or pre-emptive therapy of children at risk for candidemia. CBSIs occurring from 2006-2016 among patients in a large children's hospital were analyzed for age specific trends in incidence rate, risk factors for breakthrough-CBSI, and death, as well as underlying conditions. Candida species distributions and susceptibility patterns were evaluated in addition to the anti-fungal agent use. The overall incidence rate of CBSI among this complex patient population was 1.97/1000 patient-days. About half of CBSI episodes occurred in immunocompetent children and 14% in neonatal intensive care unit (NICU) patients. Anti-fungal resistance was minimal: 96.7% of isolates were fluconazole, 99% were micafungin, and all were amphotericin susceptible. Liposomal amphotericin was the most commonly prescribed anti-fungal agent included for NICU patients. Overall, CBSI-associated mortality was 13.7%; there were no deaths associated with CBSI among NICU patients after 2011. Pediatric CBSI characteristics differ substantially from those in adults. The improved management of underlying diseases and antimicrobial stewardship may further decrease morbidity and mortality from CBSI, while continuing to maintain low resistance rates among Candida isolates.

Candida Pathogenicity and Interplay with the Immune System

Candida species are opportunistic fungal pathogens that are part of the normal skin and mucosal microflora. Overgrowth of Candida can cause infections such as thrush or life-threatening invasive candidiasis in immunocompromised patients. Though Candida albicans is highly prevalent, several non-albicans species are also isolated from nosocomial infections. Candida sp. are over presented in the gut of people with Crohn's disease and certain types of neurological disorders, with hyphal form and biofilms being the most virulent states. In addition, Candida uses several secreted and cell surface molecules such as pH related antigen 1, High affinity glucose transporter, Phosphoglycerate mutase 1 and lipases to establish pathogenicity. A strong innate immune response is elicited against Candida via dendritic cells, neutrophils and macrophages. All three complement pathways are also activated. Production of proinflammatory cytokines IL-10 and IL-12 signal differentiation of CD4⁺ cells into Th1 and Th2 cells, whereas IL-6, IL-17 and IL-23 induce Th17 cells. Importance of T-lymphocytes is reflected in depleted T-cell count patients being more prone to Candidiasis. Anti- Candida antibodies also play a role against candidiasis using various mechanisms such as targeting virulent enzymes and exhibiting direct candidacidal activity. However, the significance of antibody response during infection remains controversial. Furthermore, some of the Candida strains have evolved molecular strategies to evade the sophisticated host attack by proteolysis of components of immune system and interfering with immune signalling pathways. Emergence of several non-albicans species that are resistant to current antifungal agents makes treatment more difficult. Therefore, deeper insight into interactions between Candida and the host immune system is required for discovery of novel therapeutic options.

Epidemiological profile of patients hospitalized with candiduria in the Central-Western region of Brazil

BACKGROUND

Candida yeasts are considered the main agents of nosocomial fungal infections.

AIMS

This study aimed to establish the epidemiological profile of patients with candiduria hospitalized in the capital of the State of Mato Grosso, in the Central-Western region of Brazil.

METHODS

Patients from three private hospitals and a public hospital participated in the study. This was an observational and cross-sectional study including analysis of patients mortality. It was carried out from March to August 2015.

RESULTS

A total of 93 patients with candiduria were evaluated. Candida tropicalis was found most commonly (37.6%; n=35), followed by Candida albicans (36.6%; n=34), Candida glabrata (19.3%; n=18), psilosis complex (4.3%; n=4), Candida lusitaniae (1.1%; n=1) and Candida krusei (1.1%; n=1). Antibiotic therapy (100%) and the use of an indwelling urinary catheter (89.2%; n=83) were the most frequent predisposing factors. Antifungal treatment was given to 65.6% of the patients, and anidulafungin was the most used antifungal. Mortality rates were 48% higher among patients with candiduria who had renal failure. Micafungin was the antifungal most prescribed among the patients who died. Candidemia concomitant with candiduria occurred in eight (8.6%; n=8) cases. Considering the species recovered in the blood and urine, only one patient had genetically distinct clinical isolates.

CONCLUSIONS

Non-C. albicans Candida species were predominant, with C. tropicalis being the most responsible for most cases of candiduria.

Neonatal and Pediatric Candidemia: Results From Population-Based Active Laboratory Surveillance in Four US Locations, 2009-2015

INTRODUCTION

Candida is a leading cause of healthcare-associated bloodstream infections in the United States. Infants and children have unique risk factors for candidemia, and the Candida species distribution in this group is different that among adults; however, candidemia epidemiology in this population has not been described recently.

METHODS

We conducted active population-based candidemia surveillance in 4 US metropolitan areas between 2009 and 2015. We calculated incidences among neonates (0-30 days old), infants (0-364 days old), and noninfant children (1-19 years old), documented their clinical features and antifungal drug resistance.

RESULTS

We identified 307 pediatric candidemia cases. Incidence trends varied according to site, but overall, the incidence in neonates decreased from 31.5 cases/100000 births in 2009 to 10.7 to 11.8 cases/100000 births between 2012 and 2015, the incidence in infants decreased from 52.1 cases/100000 in 2009 to 15.7 to 17.5 between 2012 and 2015, and the incidence in noninfant children decreased steadily from 1.8 cases/100000 in 2009 to 0.8 in 2014. Common underlying conditions were prematurity in neonates (78%), surgery in nonneonate infants (38%), and malignancy in noninfant children (28%). Most neonate cases were caused by C albicans (67%), whereas non-C. albicans species accounted for 60% of cases in nonneonate infants and noninfant children. Fluconazole and echinocandin resistance rates were low overall. Thirty-day crude mortality was 13%.

CONCLUSIONS

The incidence of candidemia among neonates and infants declined after 2009 but remained stable from 2012 to 2015. Antifungal drug resistance is uncommon. Reasons for the lack of recent declines in neonatal and infant candidemia deserve further exploration. In this article, we describe the epidemiology of candidemia in children in the United States and on the basis of data collected as part of US Centers for Disease Control and Prevention active population-based surveillance. Trends in incidence, clinical characteristics, species distribution, and resistance rates are presented.

Candidemia in children: Epidemiology, prevention and management

Candidemia is the leading cause of invasive fungal infections in hospitalised children. The highest rates of candidemia have been recorded in neonates and infants <1 year of age. Candidemia is more frequent in neonates and young infants than in adults, and is associated with better clinical outcomes, but higher inpatient costs. Over the last 10 years, a declining trend has been noted in the incidence of paediatric candidemia in the US and elsewhere due to the hospital-wide implementation of central-line insertion and maintenance bundles that emphasise full sterile barrier precautions, chlorhexidine skin preparation during line insertion, meticulous site and tubing care, and daily discussion of catheter necessity. Additional interventions aiming at reducing gut-associated candidemia are required in immunocompromised and critically ill children.

Pharmacodynamic studies of voriconazole: informing the clinical management of invasive fungal infections

INTRODUCTION

Voriconazole is a broad-spectrum antifungal agent commonly used to treat invasive fungal infections (IFI), including aspergillosis, candidiasis, Scedosporium infection, and Fusarium infection. IFI often occur in immunocompromised patients, leading to increased morbidity and mortality.

AREAS COVERED

The objective of this review is to summarize the pharmacodynamic properties of voriconazole and to provide considerations for potential optimal dosing strategies. Studies have demonstrated superior clinical response when an AUC/MIC >25 or Cmin/MIC >1 is attained in adult patients, correlating to a trough concentration range as narrow as 2-4.5 mg/L; however, these targets are poorly established in the pediatric population. Topics in this discussion include voriconazole use in multiple age groups, predisposing patient factors for IFI, and considerations for clinicians managing IFI. Expert commentary: The relationship between voriconazole dosing and exposure is not well defined due to the large inter- and intra-subject variability. Development of comprehensive decision support tools for individualizing dosing, particularly in children who require higher dosing, will help to increase the probability of achieving therapeutic efficacy and decrease sub-therapeutic dosing and adverse events.

Invasive fungal infection in patients with hematologic disorders in a Brazilian tertiary care hospital

INTRODUCTION:

Invasive fungal infections (IFIs) are an important complication in immunocompromised individuals, particularly neutropenic patients with hematological malignancies. In this study, we aimed to verify the epidemiology and diagnosis of IFIs in patients with hematologic problems at a tertiary hospital in Goiânia-GO, Brazil.

METHODS:

Data from 117 patients, involving 19 cases of IFIs, were collected. The collected data included diagnosis methods, demographics, clinical characteristics, and in vitro susceptibility to different antifungal agents. Among the 19 cases, 12 were classified as proven IFI and 7 as probable invasive aspergillosis with detection of galactomannan in blood and presence of lung infiltrates in radiographic images. Logistic regression analysis showed that the proven and probable IFIs were associated with increased risk of death. Statistical analysis demonstrated that age, sex, and underlying disease were not independently associated with risk of death in IFI patients.

RESULTS:

Most bloodstream isolates of Candida spp. exhibited low minimum inhibitory concentrations (MICs) to all antifungal agents tested. Voriconazole and amphotericin had the lowest MICs for Aspergillus spp. and Fusarium spp., but Fusarium spp. showed the least susceptibility to all antifungals tested. Amphotericin B, fluconazole, and itraconazole were found to be inactive in vitro against Acremonium kiliense; but this fungus was sensitive to voriconazole.

CONCLUSIONS:

Considering the high number of IFI cases, with crude mortality rate of 6%, we could conclude that IFIs remain a common infection in patients with hematological malignancies and underdiagnosed ante mortem. Thus, IFIs should be monitored closely.

Prevalence of fungemia in a tertiary hospital: Analysis of the last decade

INTRODUCTION

The prevalence of nosocomial fungemia has increased worldwide, and mortality caused by this disease is high.

OBJECTIVE

To assess progress in the last decade, and the prevalence and profile of fungal agents isolated in blood cultures performed in a tertiary university hospital.

METHOD

All the results of blood cultures processed at Hospital das Clínicas, Universidade Federal de Minas Gerais (HC-UFMG), in the time intervals 2001-2003 and 2011-2013 were analyzed retrospectively. For each three-year period, the number of collected blood cultures, the overall positivity rate and the percentage of fungemia were recorded. In addition, all identified fungal species were cataloged. All blood samples were incubated in the BacT/ALERT® (bioMérieux) automation system.

RESULTS

In 2001-2003, 34,822 samples were evaluated, with 5,510 (15.8%) positive results. In 2011-2013, the number of blood cultures processed increased to 55,052 samples, with 4,873 (8.9%) positive results. There was an increase in the number of positive cultures for fungi in the analyzed period (2001-2003: 4.16%; 2011-2013: 5.95%; p<0.001). Among the agents, candidemias were predominant, especially those caused by non-albicans Candida species (2001-2003: 57.64%; 2011-2013: 65.17%; p<0.05). There was also an increase in fungemia caused by other genera (2001-2003: 2.62%; 2011-2013: 4.48%; p<0.01).

CONCLUSION

There was an increase in the prevalence of fungemia in the last decade at HC-UFMG. Although candidemias have been responsible for most of the cases, there has been an increase in fungemias caused by other species.

Pathogenic factors in Candida biofilm-related infectious diseases

Candida albicans is a commonly found member of the human microflora and is a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various micro-organisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases. In addition, extracellular DNA (eDNA) also plays a crucial role in Candida biofilm formation and its structural integrity and induces the morphological transition from yeast to the hyphal growth form during C. albicans biofilm development. This review focuses on pathogenic factors such as eDNA in Candida biofilm formation and its ECM production and provides meaningful information for future studies to develop a novel strategy to battle infectious diseases elicited by Candida-formed biofilm.

Epidemiologic and microbiologic evaluation of nosocomial infections associated with Candida spp in children: A multicenter study from Istanbul, Turkey

BACKGROUND

The purpose of this study was to establish species distribution of Candida isolates from pediatric patients in Istanbul, Turkey, and to determine risk factors associated with nosocomial Candida infections.

METHODS

This study was conducted between June 2013 and June 2014 by participation of 7 medical centers in Istanbul. Candida spp strains isolated from the clinical specimens of pediatric patients were included. Clinical features were recorded on a standardized data collection sheet.

RESULTS

A total of 134 systemic Candida infections were identified in 134 patients. The patients were admitted in pediatric and neonatal intensive care units (41.8% and 9.7%, respectively) and in pediatric wards (48.5%). Candida albicans was the most prevalent species (47%), followed by Candida parapsilosis (13.4%), Candida tropicalis (8.2%), Candida glabrata (4.5%), Candida lusitaniae (3.7%), Candida kefyr (2.2%), Candida guilliermondii (1.5%), Candida dubliniensis (0.7%), and Candida krusei (0.7%). Types of Candida infections were candidemia (50.7%), urinary tract infection (33.6%), surgical site infection (4.5%), central nervous system infection (3.7%), catheter infection (3.7%), and intra-abdominal infection (3.7%). In multivariate analysis, younger age (1-24 months) and detection of non-albicans Candida spp was found to be risk factors associated with candidemia (P = 0.040; odds ratio [OR], 4.1; 95% confidence interval [CI], 1.06-15.86; and P = 0.02; OR, 2.4; 95% CI, 1.10-5.53, respectively).

CONCLUSIONS

This study provides an update for the epidemiology of nosocomial Candida infections in Istanbul, which is important for the management of patients and implementation of appropriate infection control measures.

Usefulness of CHROMagar Candida Medium, Biochemical Methods--API ID32C and VITEK 2 Compact and Two MALDI-TOF MS Systems for Candida spp. Identification

This study was conducted to compare of the yeasts identification results obtained with two new systems using the MALDI-TOF MS technique with the ones obtained using the routine identification methods of Candida spp. in clinical microbiology laboratories. All 124 Candida spp. isolates were recovered from the routine examination of clinical specimens in microbiological laboratories and collected in the Centre of Quality Control in Microbiology in Warsaw (Poland). Our findings confirm the high agreement (98%) of fungal identification using the standard, biochemistry laboratory methods and mass spectrometry technique.

Risk Factors for Candidemia in Pediatric Patients With Congenital Heart Disease

Objective.

To identify the main risk factors for the acquisition of candidemia in children with congenital heart disease (CHD) in order to improve the clinical management of these patients.

Design.

A case-control study.

Setting.

A large tertiary-care referral center in Spain with a pediatric intensive care unit (PICU) to which more than 500 children with CHD are admitted annually.

Patients.

All patients had CHD and were admitted to the PICU during 1995-2000. Case patients were defined as patients with candidemia, and control patients were defined as patients without candidemia.

Results.

Twenty-eight case patients and 47 control subjects were included in the study. Case patients were younger (mean age [ ± SD], 12.5 ± 32.0 vs 38.0 ± 48.0 months;P< .01) and had a longer median PICU stay (19 vs 4 days;P< .01), and a greater percentage of case patients previously hadCandidaspecies isolated from specimens other than blood (eg, bronchial aspirates, urine, or skin specimens) (39% vs 4%;P<.01). Severity of clinical condition, as measured by the Therapeutic Intervention Scoring System (TISS) 1 week after PICU admission (odds ratio, 1.15; 95% confidence interval, 1.05-1.26;P<.01), and receipt of antibiotic treatment for more than 5 days (odds ratio, 13.42; 95% confidence interval, 1.31-137.13;P= .03) were independently associated with the development of candidemia.

Conclusions.

Patients with CHD who have a high TISS score 1 week after PICU admission and patients who have received prolonged antibiotic therapy should be considered at high risk for candidemia. Our results suggest that shorter courses of antibiotic therapy, routine surveillance culture forCandidaspecies, and initiation of preemptive or empirical antifungal treatment could help in the clinical management of these patients.

Secular Trends of Candidemia in a Large Tertiary-Care Hospital From 1988 to 2000: Emergence ofCandida parapsilosis

Objective:

To analyze the secular trends of candidemia in a large tertiary-care hospital to determine the overall incidence, as well as the incidence by ward and by species, and to detect the occurrence of outbreaks.

Design:

Retrospective descriptive analysis. Secular trends were calculated using the Mantel-Haenszel test.

Setting:

A large tertiary-care referral center in Spain with a pediatric intensive care unit (ICU) to which more than 500 children with congenital cardiac disease are admitted annually.

Patients:

All patients with candidemia occurring from 1988 to 2000 were included. Cases were identified from laboratory records of blood cultures.

Results:

There were 331 episodes of candidemia. The overall incidence of nosocomial candidemia was 0.6 episode per 1,000 admissions and remained stable throughout the study period (P= .925). The species most frequently isolated wasCandida albicans, but the incidence ofC. parapsilosiscandidemia increased (P= .035). In the pediatric ICU, the incidence ofC. parapsilosiswas 5.6 episodes per 1,000 admissions and it was the predominant species. Outbreaks occurred occasionally in the pediatric ICU, suggesting nosocomial transmission.

Conclusions:

During this 13-year period, the incidence of candidemia remained stable in this hospital, butC. parapsilosisincreased in frequency. Occasional outbreaks of candidemia suggested nosocomial transmission ofCandidaspecies (Infect Control Hosp Epidemiol2005;26:548-552).

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.

Biofilm as a virulence marker in Candida species in Nosocomial blood stream infection and its correlation with antifungal resistance

Nosocomial blood stream infections (BSI) due to fungi especially Candida is increasing steadily. A two year prospective study was conducted in the S.C.B. Medical College with an aim to evaluate the species distribution, antifungal susceptibility and biofilm formation of Candida spp. isolated from nosocomial BSIs. 34 Candida spp. were isolated from 359 blood cultures. Antifungal susceptibility was performed by microbroth dilution technique and both visual and spectrophotometric method were used for biofilm detection. C. tropicalis was the common spp. isolated followed by C. parapsilosis and others. Most (92%) of the isolates were susceptible to Amphoterecin-B and highest resistance was observed against Flucytosine (37%) and Fluconazole(35%). Biofilm production and antifungal resistance was observed more in nonalbicans Candida spp.

A single center's experience with Candida parapsilosis related long-term central venous access device infections: the port removal decision and its outcomes

Pediatric cancer patients have an increased risk of potentially life-threatening fungal infections such as Candida parapsilosis, associated with long-term CVADs. The Infectious Diseases Society of America (IDSA) guidelines on Candida catheter-related bloodstream infections recommend systemic antifungal therapy and catheter removal. In this study, we focused on our experience with antifungal failure due to totally implanted catheter-associated C. parapsilosis bloodstream infections. We investigated cases leading to port removal in pediatric malignancy patients and the associated patient outcomes. In the first phase of the study, a retrospective chart review was performed to collect patient information, including primary disease; time from hospitalization to port-related candidemia; antifungal drug choice; and the time at which port removal occurred. During the second phase, antifungal susceptibility tests for C. parapsilosis were performed in our microbiology laboratory. All patients had fevers and were neutropenic at the time of candidemia diagnosis. The mean duration between the first isolation of Candida parapsilosis from the port samples to the port removal was 9.75 ± 5.29 days for 11 patients. Patient fevers lasted for a mean time of 16.22 ± 6.51 days. The median recovery duration from fever after CVC removal was four days (range 2-12 days). The median duration for achieving negative blood cultures, following antifungal treatment was 18 days (range 10-27 days). Our data favored the removal of catheters in the presence of ongoing fever, as suggested by the guidelines, independent of the chosen antifungal treatment. Future studies with large samples are needed to evaluate the effects of catheter removal on mortality rates and patient outcomes.

Successful treatment of an infant infected with refractory C. parapsilosis with caspofungin

Neonatal Candida infections are the leading cause of invasive fungal infections that might cause severe morbidity or mortality in a large majority of those affected. Although Candida albicans has been the most common species, Candida parapsilosis is increasingly being recognized as an important cause of invasive candidiasis in neonates. Among the Candida species, C. parapsilosis has been commonly isolated and shown to be less susceptible in vitro to echinocandins than other Candida species. We report an infant who had refractory C. parapsilosis septicemia cured with caspofungin.

Species distribution and antifungal susceptibility profile of Candida isolates from bloodstream infections in Lima, Peru

Yeast identification and in vitro susceptibility testing provide helpful information for appropriate administration of antifungal treatments; however, few reports from the Latin American region have been published. The aim of this study was to identify the species present in isolates from bloodstream infections diagnosed in nine hospitals in Lima, Peru and to determine their in vitro susceptibility to four antifungal drugs. We tested and identified 153 isolates collected between October 2009 and August 2011 using standard methods. PCR and PCR-RFLP assays were performed to distinguish Candida albicans from Candida dubliniensis and to identify species of the Candida parapsilosis and Candida glabrata complexes. Antifungal susceptibility testing for fluconazole, anidulafungin and voriconazole was performed using the CSLI M27-A3 method, and amphotericin B susceptibility was determined using the Etest method. The most frequently isolated species were: C. albicans (61; 39.9 %), C. parapsilosis (43; 28.1 %), C. tropicalis (36; 23.5%) and C. glabrata (8; 5.2 %). The overall susceptibility rates were 98.0 %, 98.7 %, 98.0 % and 97.4 % for amphotericin B, fluconazole, voriconazole and anidulafungin, respectively. No isolate was resistant to more than one drug. These results showed that the rate of resistance to four antifungal drugs was low among Candida bloodstream isolates in Lima, Peru.

Genetic determinants of virulence - Candida parapsilosis

The global epidemiology of fungal infections is changing. While overall, Candida albicans remains the most common pathogen; several institutions in Europe, Asia and South America have reported the rapid emergence to predominance of Candida parapsilosis. This mini-review examines the impact of gene deletions achieved in C. parapsilosis that have been published to date. The molecular approaches to gene disruption in C. parapsilosis and the molecularly characterized genes to date are reviewed. Similar to C. albicans, factors influencing virulence in C. parapsilosis include adherence, biofilm formation, lipid metabolism, and secretion of hydrolytic enzymes such as lipases, phospholipases and secreted aspartyl proteinases. Development of a targeted gene deletion method has enabled the identification of several unique aspects of C. parapsilosis genes that play a role in host-pathogen interactions - CpLIP1, CpLIP2, SAPP1a, SAPP1b, BCR1, RBT1, CpFAS2, OLE1, FIT-2. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

Anidulafungin versus caspofungin in a mouse model of candidiasis caused by anidulafungin-susceptible Candida parapsilosis isolates with different degrees of caspofungin susceptibility

Candida parapsilosis isolates occasionally display resistance in vitro to echinocandins and cause breakthrough infections to echinocandins. The degree of the in vivo cross-resistance among echinocandins and the fitness loss associated with caspofungin (CAS) resistance of C. parapsilosis are not well studied. We compared the activities of CAS and anidulafungin (ANF), each given at 2 dosing schedules (high dose or low dose) in a nonneutropenic mouse model of invasive candidiasis (IC) caused by ANF-susceptible isolates of C. parapsilosis with different degrees of susceptibility to CAS (CAS resistant [CAS-R], MIC, >16 mg/liter; CAS intermediate [CAS-I], MIC, 4 mg/liter; and CAS susceptible [CAS-S], MIC, 2 mg/liter). We analyzed tissue fungal burden, histopathology, and weight loss patterns. Increasing CAS resistance was associated with reduced virulence of C. parapsilosis isolates (mortality rates for CAS-S versus CAS-I versus CAS-R, 100% versus 11.1% versus 0%, respectively; P < 0.001). High doses of either echinocandin were active against infection with the CAS-I isolate when assessed by fungal burden reduction and weight gain. In contrast to CAS-S and CAS-I isolates, there was no reduction in fungal burden in mice infected with the CAS-R isolate following treatment with either echinocandin, each given at a high or low dose. Nevertheless, mice infected with the CAS-R isolate had reduced disease severity following echinocandin treatment, suggesting that echinocandins have activity in vivo, even against echinocandin-resistant strains. A complex interplay of residual echinocandin activity, decreased virulence, and/or fitness of isolates with altered cell wall and possible immunomodulatory effects can be encountered in vivo during infection with CAS-resistant C. parapsilosis isolates.

A prospective study of the patterns and dynamics of colonization with Candida spp. in very low birth weight neonates

BACKGROUND

Knowledge of fungal colonization patterns in very low birth weight infants (VLBWI) admitted to the neonatal intensive care unit (NICU) is essential in understanding the process of fungal infections in neonates. We analyzed prospectively, during 2009-2010, the patterns and dynamics of fungal colonization in VLBWI, including timing, colonization sites, and species involved.

METHODS

Weekly skin, oropharynx, and rectum/stool surveillance fungal cultures were collected from admission until discharge in VLBWI in the NICU. None received antifungal prophylaxis.

RESULTS

Overall, 118 VLBWI provided 1723 samples; 34 (29%) had 104 positive samples at least once during the first 10 hospitalization weeks. Thirty-nine (33%) weighed < 1000 g; 68 were delivered by cesarean section. Candida albicans (57/104, 55%) and Candida parapsilosis (26/104, 25%) were the main fungi isolated. Eight (24%) VLBWI were colonized during the first week and 23 (68%) during the second week. No differences in colonization were recorded between cesarean section and vaginally delivered VLBWI. The colonization risk at least once during the first 10 weeks was 23% for skin, 14% for oropharynx, 27% for rectum/stool, and 38% for any anatomic site sampled. Persistent colonization was recorded in 5/34 (15%), while transient colonization was found in 14/34 (41%) VLBWI; 16/34 (47%) were discharged or died colonized with Candida spp. Candidemia was diagnosed in 4 (3%) VLBWI and previous/simultaneous colonization was found in 3/4.

CONCLUSIONS

The cumulative risk of colonization, at any sampled site and at least once during follow-up, was high. Initial colonization occurred most often during the first 2 weeks of life. Colonization dynamics were characterized by various persistence, disappearance, and recolonization patterns. Candidemia was rare.

Candida parapsilosis is a significant neonatal pathogen: a systematic review and meta-analysis

BACKGROUND

Candida is the third most common cause of late-onset neonatal sepsis in infants born at <1500 g. Candida parapsilosis infections are increasingly reported in preterm neonates in association with indwelling catheters.

METHODS

We systematically reviewed neonatal literature and synthesized data pertaining to percentage of C. parapsilosis infections and mortality by meta-analyses. We also reviewed risk factors, virulence determinants, antimicrobial susceptibility patterns and outlined clinical management strategies.

RESULTS

C. parapsilosis infections comprised 33.47% (95% confidence interval [CI]: 30.02, 37.31) of all neonatal Candida infections. C. parapsilosis rates were similar in studies performed before the year 2000, 33.53% (95% CI: 30.06, 37.40) (28 studies), to those after 2000, 27.00% (95% CI: 8.25, 88.37) (8 studies). The mortality due to neonatal C. parapsilosis infections was 10.02% (95% CI: 7.66, 13.12). Geographical variations in C. parapsilosis infections included a low incidence in Europe and higher incidence in North America and Australia. Biofilm formation was a significant virulence determinant and predominant risk factors for C. parapsilosis infections were prematurity, prior colonization and catheterization. Amphotericin B remains the antifungal drug of choice and combination therapy with caspofungin or other echinocandins may be considered in resistant cases.

CONCLUSION

C. parapsilosis is a significant neonatal pathogen, comprises a third of all Candida infections and is associated with 10% mortality. Availability of tools for genetic manipulation of this organism will identify virulence determinants and organism characteristics that may explain predilection for preterm neonates. Strategies to prevent horizontal transmission in the neonatal unit are paramount in decreasing infection rates.

Candida parapsilosis and the neonate: epidemiology, virulence and host defense in a unique patient setting

Invasive candidiasis is a common problem in premature infants that leads to high morbidity and mortality. Although Candida albicans has historically been the most prominent species involved in these infections and has therefore been the subject of the most study, Candida parapsilosis is increasing in frequency, and neonates are disproportionately affected. This article reviews unique aspects of the epidemiology of this organism as well as strategies for prophylaxis against invasive candidiasis in general. Additionally, important differences between C. parapsilosis and C. albicans are coming to light related to virulence determinants and interactions with components of host immunity. These developments are reviewed while highlighting the significant gaps in our understanding that remain to be elucidated.

A review of Candida species causing blood stream infection

The incidence of candidemia has been on a rise worldwide. The epidemiology of invasive fungal infections in general and of candidemia in particular has changed in the past three decades because of a variety of factors like the AIDS epidemic, increased number of patients receiving immunosuppressive therapy for transplantation and the increasing use of antimicrobials in the hospital setups and even in the community. The important risk factors for candidemia include use of broad-spectrum antimicrobials, cancer chemotherapy, mucosal colonization by Candida species, indwelling vascular catheters like central venous catheters, etc. More than 90% of the invasive infections due to Candida species are attributed to five species-Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis and Candida krusei. However, the list of new species of Candida isolated from clinical specimens continues to grow every year. Early diagnosis and proper treatment is the key for management of candidemia cases.

Nationwide study of candidemia, antifungal use, and antifungal drug resistance in Iceland, 2000 to 2011

Candidemia is often a life-threatening infection, with highly variable incidence among countries. We conducted a nationwide study of candidemia in Iceland from 2000 to 2011, in order to determine recent trends in incidence rates, fungal species distribution, antifungal susceptibility patterns, and concurrent antifungal consumption. A total of 208 infection episodes in 199 patients were identified. The average incidence during the 12 years was 5.7 cases/100,000 population/year, which was significantly higher than that from 1990 to 1999 (4.3/100,000/year; P = 0.02). A significant reduction in the use of blood cultures was noted in the last 3 years of the study, coinciding with the economic crisis in the country (P < 0.001). Age-specific incidence rates were highest among patients at the extremes of age, 20.7/100,000 for <1 year of age and 18.1/100,000 for >60 years, and varied by gender. Age-specific incidence among males >80 years old was 28.6/100,000/year, and it was 8.3/100,000/year for females in this age group (P = 0.028). The 30-day survival rate among adult patients remained unchanged compared to that from 1990 to 1999 (70.4% versus 69.5%, P = 0.97). Candida albicans was the predominant species (56%), followed by C. glabrata (16%) and C. tropicalis (13%). The species distribution remained stable compared to that from previous decades. Fluconazole use increased 2.4-fold from 2000 to 2011, with no increase in resistance. In summary, the incidence of candidemia in Iceland has continued to increase but may have reached a steady state, and no increase in antifungal drug resistance has been noted. Decreased use of blood cultures toward the end of the study may have influenced detection rates.

Epidemiology, risk factors and outcome of Candida parapsilosis bloodstream infection in children

BACKGROUND

Candida parapsilosis constitutes a common Candida spp. isolated in children with candidemia. Few data exist on risk factors and outcome of candidemia caused by C. parapsilosis in pediatric patients.

METHODS

We conducted a retrospective analysis of demographic data, clinical features, therapeutic procedures and outcomes associated with Candida bloodstream infections (BSIs) that occurred at the Children's Hospital of Philadelphia between 1997 and 2009.

RESULTS

Among 406 Candida BSIs, Candida albicans accounted for 198 (49%), C. parapsilosis for 99 (24%) and all other species for 109 (27%) episodes. There was no consistent change in the proportion of C. parapsilosis BSIs during the study. C. parapsilosis BSI was more frequent than non-parapsilosis Candida spp. at age ≤2 years as compared with older patients (62% versus 50%, odds ratio = 1.24, 95% confidence interval: 1.03-1.51, P = 0.038). Patients with C. parapsilosis were more likely to be mechanically ventilated within 48 hours of BSI (odds ratio = 1.38, 95% confidence interval: 1.01-1.85, P = 0.047). Presence of a urinary catheter a week before infection was a protective factor for developing candidemia due to C. parapsilosis spp. (P = 0.003). No significant differences were found between the 2 groups in the presence of central intravascular catheters, comorbidities and clinical or surgical procedures, previous administration of immunosuppressive or antifungal agents and mortality.

CONCLUSIONS

C. parapsilosis is the second most frequent cause of candidemia after C. albicans. Although it is more frequent at the age of ≤2 years and is more likely associated with mechanical ventilation than other Candida spp., mortality does not significantly differ between those with and without C. parapsilosis candidemia.

Strategies for the prevention of neonatal candidiasis

Invasive fungal infections represent the third-leading cause of late-onset sepsis in very-low-birth-weight infants (VLBWI) and have a high rate of infection-associated mortality. The infants at high risk for fungal sepsis are VLBWI with presence of additional risk factors that contribute to increased colonization and concentration of fungal organisms. Colonization with Candida spp. in neonates is secondary to either maternal vertical transmission or nosocomial acquisition in the nursery. Multiple sites may become colonized and a direct correlation between fungal colonization and subsequent progression to invasive candidemia was determined. Randomized, single and multiple-center, placebo-controlled trials found intravenous fluconazole prophylaxis to be effective in decreasing fungal colonization and sepsis for at-risk preterm infants <1500 g birth weight. The prophylactic use of fluconazole was found to be safe with no significant development of fungal resistance. Fluconazole prophylaxis administered to preterm neonates with birth weight <1000 g and/or 27 weeks' gestation or less has the potential of reducing and potentially eliminating invasive fungal infections and Candida-related mortality.

Neonatal invasive candidiasis in Tunisian hospital: incidence, risk factors, distribution of species and antifungal susceptibility

The aim of our study was to assess epidemiological features of neonatal invasive candidiasis in Farhat Hached hospital of Sousse, Tunisia, including incidence, risk factors, mortality, species distribution and antifungal susceptibility. Laboratory data from 1995 to 2010 and medical records of 127 invasive candidiasis cases were reviewed. We tested the susceptibility of 100 Candida sp isolates by using ATB fungus(®) 3 and to fluconazole by using E-test(®) strips. A total of 252 cases of neonatal invasive candidiasis occurred over the study period. The incidence increased 1.8-fold from 1995 to 2006 and decreased fourfold from 2007 to 2010. Candida albicans was the predominant species up to 2006 and a shift in the species spectrum was observed with increase of the non-albicans species mainly C. parapsilosis. The agreement between the ATB Fungus(®) and the E-test(®) for determining fluconazole susceptibility was high. All tested isolates were susceptible to fluconazole, flucytosine, amphotéricine B and voriconazole and the itraconazole resistance rate was 5%. The mortality rate was 63%. The invasive candidiasis incidence increased from 1995 to 2006 and decreased from 2007 to 2010. The spectrum of Candida species and the lack of fluconazole-resistant strains argue for the usefulness of fluconazole as an empiric treatment.

Declining incidence of candidemia in a tertiary inpatient pediatric population

We examined the incidence of candidemia, Candida species distribution, and antifungal susceptibility patterns in a pediatric institution. We identified 301 episodes of candidemia from 2001 to 2010 inclusive. Annual incidence decreased from 0.68 to 0.12 cases/1,000 patient days between 2004 and 2010. Candida albicans was the most common species, followed by C. parapsilosis. All isolates tested were susceptible to amphotericin B and caspofungin, but 11% were resistant or dose-dependently susceptible to fluconazole.

Symptomatic and asymptomatic candidiasis in a pediatric intensive care unit

INTRODUCTION

This study aimed to examine the incidence, epidemiology, and clinical characteristics of symptomatic and asymptomatic candidiasis in a pediatric intensive care unit (PICU), and to determine the risk factors associated with symptomatic candidiasis.

METHODS

This retrospective study included 67 patients from a 7-bed PICU in a tertiary care hospital that had Candida-positive cultures between April 2007 and July 2009. Demographic and clinical characteristics of the patients, Candida isolates, antimicrobial and antifungal treatments, and previously identified risk factors for symptomatic candidiasis were recorded, and symptomatic and asymptomatic patients were compared.

RESULTS

In all, 36 (53.7%) of the patients with Candida-positive cultures had asymptomatic candidiasis and 31 (46.3%) had symptomatic candidiasis. Candida albicans was the most common Candida sp. in the asymptomatic patients (n = 20, 55.6%), versus Candida parapsilosis in the symptomatic patients (n = 15, 48.4%). The incidence of central venous catheter indwelling, blood transfusion, parenteral nutrition, and surgery was higher in the symptomatic patient group than in the asymptomatic patient group (P < 0.5). Surgery was the only independent predictor of symptomatic candidiasis according to forward stepwise multivariate logistic regression analysis (OR: 6.1; 95% CI: 1.798-20.692).

CONCLUSION

Surgery was the only risk factor significantly associated with symptomatic candidiasis and non-albicans Candida species were more common among the patients with symptomatic candidiasis. While treating symptomatic candidiasis in any PICU an increase in the incidence of non-albicans candidiasis should be considered.

Yeast identification in routine clinical microbiology laboratory and its clinical relevance

Rapid identification of yeast infections is helpful in prompt appropriate antifungal therapy. In the present study, the usefulness of chromogenic medium, slide culture technique and Vitek2 Compact (V2C) has been analysed. A total of 173 clinical isolates of yeast species were included in the study. An algorithm to identify such isolates in routine clinical microbiology laboratory was prepared and followed. Chromogenic medium was able to identify Candida albicans, C. tropicalis, C. krusei, C. parapsilosis and Trichosporon asahii. Chromogenic medium was also helpful in identifying "multi-species" yeast infections. The medium was unable to provide presumptive identification of C. pelliculosa, C. utilis, C. rugosa, C. glabrata and C. hemulonii. Vitek 2 compact (V2C) differentiated all pseudohypae non-producing yeast species. The algorithm followed was helpful in timely presumptive identification and final diagnosis of yeast infections, including multi-species yeast infections.

Prospective multicenter study of the epidemiology, molecular identification, and antifungal susceptibility of Candida parapsilosis, Candida orthopsilosis, and Candida metapsilosis isolated from patients with candidemia

A 13-month prospective multicenter study including 44 hospitals was carried out to evaluate the epidemiology of Candida parapsilosis complex candidemia in Spain. Susceptibility to amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, caspofungin, and micafungin was tested by the microdilution colorimetric method. A total of 364 C. parapsilosis complex isolates were identified by molecular methods: C. parapsilosis (90.7%), Candida orthopsilosis (8.2%), and Candida metapsilosis (1.1%). Most candidemias (C. parapsilosis, 76.4%; C. orthopsilosis, 70.0%; C. metapsilosis, 100%) were observed in adults. No C. orthopsilosis or C. metapsilosis candidemias occurred in neonates. C. parapsilosis was most frequent in adult intensive care unit (28.8%), surgery (20.9%), and internal medicine (19.7%) departments; and C. orthopsilosis was most frequent in hematology (28.6%), pediatrics (12.0%), and neonatology (11.5%) departments. The geographic distribution of C. orthopsilosis and C. metapsilosis was not uniform. According to CLSI clinical breakpoints, all C. orthopsilosis and C. metapsilosis isolates were susceptible to the nine agents tested. Resistance (MICs > 1 mg/liter) was observed only in C. parapsilosis: amphotericin B, posaconazole, itraconazole, and caspofungin (0.3% each), anidulafungin (1.9%), and micafungin (2.5%). Applying the new species-specific fluconazole and echinocandin breakpoints, the rates of resistance to fluconazole for C. parapsilosis and C. orthopsilosis increased to 4.8% and 0.3%, respectively; conversely, for C. parapsilosis they shifted from 1.9 to 0.6% (anidulafungin) and from 2.5 to 0.6% (micafungin). Our study confirms the different prevalence of C. parapsilosis complex candidemia among age groups: neither C. orthopsilosis nor C. metapsilosis was isolated from neonates; interestingly, C. metapsilosis was isolated only from adults and the elderly. The disparity in antifungal susceptibility among species could be important for therapy.

Candida non-albicans versus Candida albicans fungemia in the non-neonatal pediatric population

BACKGROUND

Non-albicans Candida (NAC) species have been implicated as major pathogens in patients with hospital-acquired candidemia. Few studies have investigated the impact of NAC fungemia among pediatric patients outside of the neonatal age group.

MATERIALS/METHODS

Between 2000 and 2009, we performed a retrospective case-control study in children aged 6 months to ≤18 years with blood culture proven candidemia at Texas Children's Hospital, Houston, TX.

RESULTS

A total of 276 episodes of candidemia occurred in 226 patients. The overall incidence ranged between 0.06 and 0.3 per 1000 inpatient days. The median patient age was 50 months (range, 6 months to ≤18 years) with 55.4% males; 40.2% Hispanics; and 31.8% whites. Candida albicans (CA) was the most common (44.2%) species although, collectively, NAC was more frequently (55.8%) isolated. Among the NAC group, Candida parapsilosis was most common (23.9%) followed by Candida tropicalis (14.8%), Candida glabrata (6.5%), and Candida lusitaniae (5.4%). No difference was found between CA and NAC candidemia in terms of demographics, underlying diagnosis, risk factors, clinical features, dissemination, or 30-day mortality. Disseminated candidiasis was independently associated with the use of vasopressors (adjusted odds ratio [OR], 4.58; confidence interval [CI]: 1.03-20.5; P = 0.05), prolonged fungemia (≥3 days of persistently positive cultures) after catheter removal (OR, 3.2; CI: 1.08-9.3; P = 0.04), and neutropenia (OR, 4.06; CI: 1.2-13.2; P = 0.02), but not with NAC fungemia.

CONCLUSIONS

Though CA was the single most common species, NAC species collectively have emerged as the predominant pathogens responsible for candidemia in non-neonatal patients at our institution. Risk factors, clinical features, and outcomes were not different between the 2 groups.

Characterization of the Candida parapsilosis complex in East China: species distribution differs among cities

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 China, data pertaining to these fungi are limited. In this study, we examined 57 isolates of members of the C. parapsilosis complex collected from four cities in East China, i.e., Nanjing (n = 22), Nanchang (n = 20), Shanghai (n = 12) and Jinan (n = 3). C. parapsilosis sensu stricto represented 71.9% of all isolates, while C. metapsilosis accounted for the remaining 28.1%. C. orthopsilosis could not be identified. A significantly high prevalence of C. metapsilosis was observed in strains recovered from Nanchang, 60% (12/20) of the isolates were C. metapsilosis. Sequence analysis of internal transcribed spacer region revealed two unevenly distributed genotypes among the C. metapsilosis strains. A PCR-restriction fragment length polymorphism assay was described for rapid identification. The strains were susceptible to fluconazole, voriconazole, amphoterincin B and micafungin. Six (15%) isolates of C. parapsilosis sensu stricto and three (18.8%) of C. metapsilosis were found to be dose-dependent susceptible to itraconazole. C. parapsilosis sensu stricto strains were less susceptible to micafungin than C. metapsilosis.

A rat model of neonatal candidiasis demonstrates the importance of lipases as virulence factors for Candida albicans and Candida parapsilosis

The host factors that contribute to the increased susceptibility of preterm neonates to invasive candidiasis have not been fully identified. In addition, there has been a lack of suitable models to study this problem. We show that rat pups, similar to premature neonates, display increased susceptibility to experimental Candida albicans infection. Further, we find that both C. albicans and Candida parapsilosis lipase disruptant mutants exhibit decreased virulence in rat pups, demonstrating the utility of the model to evaluate the impact of specific genes in disease pathogenesis. Our findings highlight the contribution of lipases to the virulence of C. albicans and C. parapsilosis and provide a new system to study the increased susceptibility of neonates to Candida infections.

Nosocomial fungal infections: epidemiology, infection control, and prevention

Fungal infections are an increasing cause of morbidity and mortality in hospitalized patients. This article reviews the current epidemiology of nosocomial fungal infections in adult patients, with an emphasis on invasive candidiasis and aspergillosis. Recently published recommendations and guidelines for the control and prevention of these nosocomial fungal infections are summarized.

Invasive candidiasis in neonates and children

Invasive candidiasis is associated with high morbidity and mortality in neonates and children. The incidence of invasive candidiasis is greater in children than in adults and is particularly high in neonates. Main risk factors are multiple antibiotics, central venous catheters, parenteral nutrition, immunodepression, low birth weight, fungal colonization, and necrotizing enterocolitis. Successful management of IFIs relies on early recognition and rapid initiation of effective treatment.