Candida glabrata: an emerging pathogen in Brazilian tertiary care hospitals

Rapid identification,fluconazole and micafungin susceptibility testing of Candida species from blood culture by a short incubation method

This study aimed to develop and validate a rapid method for identification by MALDI-TOF system and determination of the susceptibility to Fluconazole and Micafungin by broth microdilution among Candidaspecies causing bloodstream infections. Subcultures from blood culture bottles were incubated for 5 hours (+/- 1h) and used to perform the tests, so that the turnaround time of rapid identification and susceptibility profile was about 5 and 24 hours, respectively. The rapid identification showed agreement of 92.05 %. Regarding the rapid broth microdilution for Fluconazole and Micafungin, the agreement was 97.06 % (p<0.001) and 100 % (p<0.001), and the Kappa coefficient was 0.91 (p<0.001) and 1.0 (p<0.001), respectively. To conclude, both rapid methods showed to be reproducible, inexpensive, easy to perform and time-saving. Thus, these methodologies could be useful to guide and adjust empirical antifungal therapy.

Prevalence and Species Distribution of Candida Clinical Isolates in a Tertiary Care Hospital in Ecuador Tested from January 2019 to February 2020

The incidence of candidemia in healthcare centers is associated with high morbidity and mortality. Frequency varies significantly among regions, with some species being more prevalent than others in Latin America. In this study, 191 clinical Candida isolates were collected from a major hospital in Ecuador from January 2019 to February 2020 aiming to assess their prevalence and distribution. After data processing, 168 isolates characterized by the VITEK 2 system were subsequently identified by ITS sequencing. Results showed diverse Candida species distributions, with C. albicans and C. tropicalis being the most prevalent across different clinical sources. In hospitalized individuals, C. tropicalis (38%) and C. albicans (37%) were the most prevalent, followed by, C. parapsilosis (16%), C. glabrata (5%), and other non-Candida albicans (NCA) species (6%). Conversely, C. parapsilosis (48%), C. albicans (20%), and C. glabrata (14%), associated with candidemia, were the most common in blood and CSF. Additionally, uncommon NCA species such as C. haemulonii, C. kefyr, and C. pelliculosa were identified in Ecuador for the first time. Discrepancies in species identification were observed between the VITEK 2 system and ITS sequencing, coinciding at 85%. This highlights the need for ongoing surveillance and identification efforts in Ecuador's clinical and epidemiological settings.

Fungemia in Hospitalized Adult Patients with Hematological Malignancies: Epidemiology and Risk Factors

Fungemia in hematologic malignancies (HM) has high mortality. This is a retrospective cohort of adult patients with HM and fungemia between 2012 and 2019 in institutions of Bogotá, Colombia. The epidemiological, clinical, and microbiological characteristics are described, and risk factors related to mortality are analyzed. One hundred five patients with a mean age of 48 years (SD 19.0) were identified, 45% with acute leukemia and 37% with lymphomas. In 42%, the HM was relapsed/refractory, 82% ECOG > 3, and 35% received antifungal prophylaxis; 57% were in neutropenia, with an average duration of 21.8 days. In 86 (82%) patients, Candida spp. was identified, and other yeasts in 18%. The most frequent of the isolates were non-albicans Candida (61%), C. tropicalis (28%), C. parapsilosis (17%), and C. krusei (12%). The overall 30-day mortality was 50%. The survival probability at day 30 in patients with leukemia vs. lymphoma/multiple myeloma (MM0 group was 59% (95% CI 46-76) and 41% (95% CI 29-58), p = 0.03, respectively. Patients with lymphoma or MM (HR 1.72; 95% CI 0.58-2.03) and ICU admission (HR 3.08; 95% CI 1.12-3.74) were associated with mortality. In conclusion, in patients with HM, non-albicans Candida species are the most frequent, and high mortality was identified; moreover, lymphoma or MM and ICU admission were predictors of mortality.

The Anti-Virulence Effect of Vismia guianensis against Candida albicans and Candida glabrata

In folk medicine, Vismia guianensis is used to treat skin diseases and mycoses in the Amazon region. We evaluated the anti-Candida activity of the hydroalcoholic extract from the leaves of Vismia guianensis (EHVG). HPLC-PDA and FIA-ESI-IT-MSⁿ were used to chemically characterize EHVG. The anti-Candida activity was determined in vitro by the minimum inhibitory concentrations (MIC) against Candida glabrata (ATCC-2001); Candida albicans (ATCC-90028, ATCC-14053, and ATCC-SC5314), and C. albicans clinical isolates. EHVG effects on adhesion, growth, and biofilm formation were also determined. Molecular docking was used to predict targets for EHVG compounds. The main compounds identified included anthraquinone, vismione D, kaempferol, quercetin, and vitexin. EHVG was fungicidal against all tested strains. C. albicans ATCC 14053 and C. glabrata ATCC 2001 were the most sensitive strains, as the extract inhibited their virulence factors. In silico analysis indicated that vismione D presented the best antifungal activity, since it was the most effective in inhibiting CaCYP51, and may act as anti-inflammatory and antioxidant agent, according to the online PASS prediction. Overall, the data demonstrate that EHVG has an anti-Candida effect by inhibiting virulence factors of the fungi. This activity may be related to its vismione D content, indicating this compound may represent a new perspective for treating diseases caused by Candida sp.

Antifungal susceptibility profile of Candida clinical isolates from 22 hospitals of São Paulo State, Brazil

This study aimed to evaluate the frequency of cryptic Candida species from candidemia cases in 22 public hospitals in São Paulo State, Brazil, and their antifungal susceptibility profiles. During 2017 and 2018, 144 isolates were molecularly identified as 14 species; C. parapsilosis (32.6%), C. albicans (27.7%), C. tropicalis (14.6%), C. glabrata (9.7%), C. krusei (2.8%), C. orthopsilosis (2.8%), C. haemulonii var. vulnera (2.1%), C. haemulonii (1.4%), C. metapsilosis (1.4%), C. dubliniensis (1.4%), C. guilliermondii (1.4%), C. duobushaemulonii (0.7%), C. kefyr (0.7%), and C. pelliculosa (0.7%). Poor susceptibility to fluconazole was identified in 6.4% of C. parapsilosis isolates (0.12 to >64 µg/mL), 50% of C. guilliermondii (64 µg/mL), 66.6% of C. haemulonii var. vulnera (16-32 µg/mL), and C. duobushaemulonii strain (MIC 64 µg/mL). Our results corroborated the emergence of C. glabrata in Brazilian cases of candidemia as previously reported. Importantly, we observed a large proportion of non-wild type C. glabrata isolates to voriconazole (28.6%; <0.015 to 4 µg/mL) all of which were also resistant to fluconazole (28.6%). Of note, C. haemulonii, a multidrug resistant species, has emerged in the Southeast region of Brazil. Our findings suggested a possible epidemiologic change in the region with an increase in fluconazole-resistant species causing candidemia. We stress the relevance of routine accurate identification to properly manage therapy and monitor epidemiologic trends.

Genetic Analysis of Candida glabrata from Candiduric Patients Using Microsatellite Length Polymorphism, Antifungal Susceptibility, and Enzymatic Profiles

Background: Candida glabrata is the second agent of candiduria with increased resistance to antifungals. Microsatellite length polymorphism (MLP) is one of the genotyping techniques used in the epidemiological investigation to improve clinical management. Objectives: We aimed to detect different genotypes of C. glabrata isolates using six microsatellite markers and the MLP technique. Moreover, our genotypes' association with other countries' genotypes was illustrated using a minimum spanning tree. We investigated in vitro antifungal susceptibility and enzymatic activity profiles of the isolates. Methods: Six microsatellite markers were amplified using multiplex-PCR for 22 C. glabrata strains isolated from urine in pediatric patients admitted to the Abuzar Children's Hospital in Ahvaz, Iran. The PCR products were presented for fragment analysis, and the size of the alleles was determined. Antifungal susceptibility tests and extracellular enzyme activities were also performed. Results: Nineteen multilocus genotypes were detected so that 22.7% of the strains had identical genotypes. The isolates were wild-type for amphotericin B (0.0625 - 2 µg/mL), itraconazole (0.125 - 2 µg/mL), and voriconazole (0.0078 - 0.00625 µg/mL). All the isolates were sensitive to fluconazole at the minimum inhibitory concentration (MIC) range (0.0312 - 16 μg/mL), and three of them were resistant to caspofungin (MIC ≥ 0.5 μg/mL). Moreover, 72.7 and 68.2% of the isolates had no phospholipase and esterase activities. The highest potency of enzymatic activity was obtained in hemolysin and proteinase enzymes. A high genetic diversity (19 genotypes of the 22 isolates) existed among the urinary C. glabrata isolates. Based on the minimum spanning tree, two clusters of our genotypes were related to C. glabrata genotypes in a previous study in Iran, and the third cluster was entirely connected with Chinese genotypes. Conclusions: Most of the isolates were the non-wild type for posaconazole but were rarely resistant to other antifungals. Hemolysin and proteinase secreted as the main virulence factors among the urinary C. glabrata isolates.

Trends towards lower azole susceptibility among 200 Candida tropicalis bloodstream isolates from Brazilian medical centres

OBJECTIVES

Candida tropicalis is one of the three most frequent species causing candidaemia in Latin America. Despite the high prevalence of C. tropicalis in candidaemia cases in Brazil, little is known about the trends in fluconazole susceptibility over time. The objective of this study was to evaluate temporal trends in azole resistance rates among C. tropicalis bloodstream isolates from patients treated in six Brazilian medical centres over a 12-year period.

METHODS

We selected 200 C. tropicalis bloodstream isolates from six medical centres in Brazil collected between 2007 and 2018. Species identification was confirmed by MALDI-TOF/MS. Antifungal susceptibility testing for four antifungal agents was performed by the Clinical and Laboratory Standards Institute (CLSI) microbroth method.

RESULTS

Overall, rates of non-susceptibility were 4% and 3.5% to fluconazole and voriconazole, respectively. All isolates were susceptible to amphotericin B and only one isolate was resistant to echinocandins.

CONCLUSION

Although we failed to demonstrate statistical differences in the rates of azole resistance documented during the period of analysis, trends towards lower susceptibility to fluconazole and voriconazole were shown.

Emphysematous pyelonephritis caused by C. glabrata

Emphysematous pyelonephritis (EPN) is a rare acute necrotizing infection of the kidney and surrounding tissues, with gas in the renal parenchyma, collecting system or perirenal tissue. The bacterial etiology predominates; mainly Gram-negative bacilli; Candida spp. and C. albicans are rarely described. We describe a case of EPN caused by C. glabrata, sensitive to fluconazole in a young, hypertensive woman with undiagnosed diabetes mellitus (DM), with renal dysfunction upon admission; her abdominal CT scan found a volumetric increase in the left kidney, signs of gas collections and perirenal blurring. Despite the antimicrobial therapy instituted, due to clinical refractoriness, a double J catheter and subsequent total nephrectomy were indicated, with good postoperative evolution. Her uroculture showed C. glabrata sensitive to fluconazole, and the pathology study showed tubular atrophy and intense interstitial inflammatory infiltrate. Despite the serious, potentially fatal condition, we could control the infection and the patient recovered fully. Poor DM management is an important triggering factor, and it is of great relevance to identify the EPN through imaging exams due to the peculiarities of its clinical and potentially surgical management

Genotypic diversity and antifungal susceptibility pattern of Candida albicans species isolated from hospitalized paediatric patients with urinary tract infection in Iran

AIMS

The present study aimed to determine the microsatellite length polymorphism (MLP) genotypic patterns and antifungal susceptibility profiles of Candida albicans isolated from patients with candiduria.

METHODS AND RESULTS

DNA of 50 C. albicans isolates was used for molecular identification based on the ITS₁ -5.8s-ITS₂ region. MLP assays were performed to amplify three loci (EF3, CDC3 and HIS3), and PCR products were used for fragment analysis. Antifungal susceptibility tests were performed according to CLSI M27 4th ed guidelines. In all, 38 different genotypes were detected with the three polymorphic loci among C. albicans isolates, and only one genotype was homozygous. In comparison to other countries, our genotypes were divided into three clusters, two of which were linked to France and a third of which was linked to Austria. The genetic structures of the 50 C. albicans isolates revealed varied heterozygosity and significant Hardy-Weinberg equilibrium at the EF3 locus. Only one (2%) and four (8%) of isolates showed resistance to fluconazole and itraconazole, respectively. In C. albicans genotype G25, one (2%) of the isolates showed cross-resistance and non-wild-type resistance to posaconazole, itraconazole and fluconazole.

CONCLUSION

MLP typing is a useful tool to analyse the genetic structure of C. albicans isolates. High genetic diversity (38 genotypes) was detected in the isolates tested here. Compared to isolates in other countries, the ones from our patients had a clear relationship with French and Austrian isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

Iranian isolates of C. albicans have a distinct genotype and show similarities only with French and Austrian isolates.

High prevalence of asymptomatic nosocomial candiduria due to Candida glabrata among hospitalized patients with heart failure: a matter of some concern?

Background and Purpose:

Heart failure is a leading cause of hospitalization, and asymptomatic candiduria is common in hospitalized patients with low morbidity. However, in most patients, it is resolved spontaneously on the removal of the catheter. Despite the publication of guidelines, there are still controversies over the diagnosis and management of candiduria. However, in hospitalized patients with heart failure, the decision to treat candiduria is especially important since the nosocomial infections are associated with an increase in morbidity, mortality, length of hospital stay, and healthcare costs. Some species of Candida, such as Candida glabrata, are increasingly resistant to the first-line and second-line antifungal medications. The present study aimed to investigate the incidence of asymptomatic Candida urinary tract infection due to C. glabrata and antifungal susceptibility of Candida isolates in hospitalized patients with heart failure.

Materials and Methods:

In total, 305 hospitalized patients with heart failure were studied to identify asymptomatic nosocomial candiduria during 2016-17 in one private hospital in the north of Iran. The Sabouraud’s dextrose agar culture plates with a colony count of >10⁴ colony-forming unit/ml of urine sample were considered as Candida urinary tract infection. Candida species were identified based on the morphology of CHROMagar Candida (manufactured by CHROMagar, France) and PCR-RFLP method with MspI restriction enzyme. Antifungal susceptibility testing of the isolates was performed using five mediations, including itraconazole, voriconazole, fluconazole, amphotericin B, and caspofungin by broth microdilution method according to CLSI M27-S4.

Results:

In this study, the rate of asymptomatic Candida urinary tract infection was 18.8%, which was more common in people above 51 years old and females (70%). In addition to the urinary and intravascular catheter, the occurrence of candiduria in hospitalized patients had significant relationships with a history of surgical intervention, diastolic heart failure, and use of systemic antibiotics (P>0.05). Among Candida spp., non-albicans Candida species was the most common infectious agent (59.7%). Moreover, C. glabrata (n=27, 40.3%) (alone or with other species) and Candida albicans (n=27, 40.3%) were the most common agents isolated in Candida urinary tract infection. Based on the results of the in vitro susceptibility test, the C. glabrata isolates were 15%, 59%, 70%, 74%, and 85% susceptible to caspofungin, amphotericin B, itraconazole, voriconazole, and fluconazole, respectively.

Conclusion:

According to the findings, there was a high prevalence of asymptomatic Candida urinary tract infection in hospitalized patients with heart failure. Besides, it was suggested that there was a shift towards non-albicans Candida, especially C. glabrata, in these patients. Therefore, asymptomatic candiduria in hospitalized patients with heart failure should be considered significant. Furthermore, the identification of Candida species along with antifungal susceptibility is essential and helps the clinicians to select the appropriate antifungal agent for better management of such cases.

Clinical and epidemiological aspects of Candidemia in eight medical centers in the state of Parana, Brazil: Parana Candidemia Network

Objectives

Candida spp. has been reported as one of the common agents of nosocomial bloodstream infections and is associated with a high mortality. Therefore, this study evaluated the clinical findings, local epidemiology, and microbiological aspects of candidemia in eight tertiary medical centers in the state of Parana, South of Brazil.

Methods

In this study, we reported 100 episodes of candidemia in patients admitted to eight different hospitals in five cities of the state of Parana, Brazil, using data collected locally (2016 and 2017) and tabulated online.

Results

The incidence was found to be 2.7 / 1000 patients / day and 1.2 / 1000 admissions. C. albicans was responsible for 49% of all candidemia episodes. Cancer and surgery were the two most common underlying conditions associated with candidemia. The mortality rate within 30 days was 48%, and removal of the central venous catheter (p = 0.029) as well as empirical or prophylactic exposure to antifungals were both related to improved survival (p = 0.033).

Conclusions

This study highlights the high burden and mortality rates of candidemia in hospitals from Parana as well as the need to enhance antifungal stewardship program in the enrolled medical centers.

(1,3)-β-D-glucan is able to predict therapeutic failure of patients with candidemia and not only mortality

BACKGROUND

Candidemia is a major cause of bloodstream infection in tertiary hospitals worldwide and fungal biomarkers may provide early diagnosis.

OBJECTIVES

To evaluate the performance of (1-3)-β-D-glucan (BDG) in the diagnosis of candidemia and its ability to predict therapeutic failure.

PATIENTS AND METHODS

This was a prospective, multi-centre study conducted in 3 Brazilian hospitals. Clinical outcome was evaluated along 2 weeks of treatment, and therapeutic failure was defined as the occurrence of persistent candidemia, Candida deep-seated infection or death. Baseline BDG detection was performed with the Fungitell^® assay (Associates of Cape Cod, Falmouth-USA).

RESULTS

We enrolled a total of 71 patients with candidemia and a control group with 110 healthy volunteers. The sensitivity and specificity of BDG for diagnosing candidemia were as follows: 71.8% (95% confidence interval [95% CI] 59.7% - 81.5%) and 98.2% (95% CI 92.9% - 99.7%), respectively. The only predictor of therapeutic failure was a higher BDG value at diagnosis of candidemia; a value > 226 pg/mL predicted failure with sensitivity and specificity of 75% and 78%, respectively.

CONCLUSIONS

A high baseline serum BDG value was associated with therapeutic failure.

The secreted acid trehalase encoded by the CgATH1 gene is involved in Candida glabrata virulence

BACKGROUND

Candida glabrata yeast is the second cause of candidiasis worldwide. Differs from other yeasts since assimilates only glucose and trehalose (a characteristic used in rapid identification tests for this pathogen) by secreting into the medium a highly active acid trehalase encoded by the CgATH1 gene.

OBJECTIVE

This study aimed to characterise the function of the acid trehalase in the physiopathology of C. glabrata.

METHODS

Gene deletion was performed to obtain a mutant ath1Δ strain, and the ability of the ath1Δ strain to grow in trehalase, or the presence of trehalase activity in the ath1Δ yeast cells, was verified. We also tested the virulence of the ath1Δ strain in a murine model of infection.

FINDINGS

The ath1Δ mutant strain grows normally in the presence of glucose, but loses its ability to grow in trehalose. Due to the high acid trehalase activity present in wild-type cells, the cytoplasmic neutral trehalase activity is only detected in the ath1Δ strain. We also observed a significantly lower virulence of the ath1Δ strain in a murine model of infection with either normal or immunocompromised mice.

MAIN CONCLUSIONS

The acid trehalase is involved in the hydrolysis of external trehalose by C. glabrata, and the enzyme also plays a major virulence role during infectivity.

Candidaemia Mortality Has not Changed Over the Last 2 Decades in Brazil

Despite advances in fungal diagnostics and antifungal therapy, mortality associated with candidaemia remains very high, particularly in developing countries. In this study, we reviewed the Brazilian literature on candidaemia over the last 20 years (1999-2019), with the aim to document if mortality rates changed over the years in Brazil. Variables studied included number of patients with candidaemia per study, age, most prevalent Candida species and use of antifungals. Selected manuscripts evaluated a median of 114 patients, the majority being men (54.4%). Median age was 45 year-old. The most prevalent species in all studies was C. albicans (37.3%), followed by C. parapsilosis (23.0%). An increase in use of echinocandins occurred in recent years, with a proportional decrease in the use of fluconazole and amphotericin B. Surprisingly, mortality of candidaemia has remained unchanged over the years in the largest Latin American country, regardless of treatment with echinocandins. Potential explanations for these findings are discussed.

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.

Prevalence and Antifungal Susceptibility of the Emerging Fungal Species, Candida nivariensis, Isolated in a Teaching Hospital in Poland

The data on susceptibility to antifungals of new species within Candida glabrata complex are limited. Our study was to enrich a global knowledge of yeast epidemiology and drug resistance. The study was focused on the identification of species within clinical isolates of the C. glabrata complex and on the determination of their resistance to antifungals. Four hundred forty-five clinical C. glabrata sensu lato strains were isolated from different clinical samples at routine mycological exams at the Infant Jesus Teaching Hospital in Warsaw. The identification of the most of tested isolates to species complex level was performed using the ID 32 C system. The identification of C. nivariensis and C. bracarensis species within the C. glabrata complex was performed by DNA sequencing. The MICs of amphotericin B, fluconazole, itraconazole, posaconazole, voriconazole, caspofungin, anidulafungin, and micafungin were determined by E-test. Twenty-four isolates did not have an ITS-1 region, characteristic of C. glabrata sensu stricto and their D1/D2 regions of the 26S rRNA were 99% homologous to C. nivariensis 26S rRNA. No strains of C. bracarensis were recovered. C. nivariensis strains were very susceptible to amphotericin B, anidulafungin, micafungin, and caspofungin. Ninety-two percent of C. nivariensis were resistant to itraconazole. The halves of the strains was resistant to posaconazole. Eighty-three percent of C. nivariensis were susceptible to voriconazole. None of the tested strains were susceptible to fluconazole. In the present study, none of the C. nivariensis strains were simultaneously resistant to azoles and echinocandins. C. nivariensis should be recognized as an emerging pathogen, resistant to azoles.

Epidemiology and prognostic factors of nosocomial candidemia in Northeast Brazil: A six-year retrospective study

Candidemia has been considered a persistent public health problem with great impact on hospital costs and high mortality. We aimed to evaluate the epidemiology and prognostic factors of candidemia in a tertiary hospital in Northeast Brazil from January 2011 to December 2016. Demographic and clinical data of patients were retrospectively obtained from medical records and antifungal susceptibility profiling was performed using the broth microdilution method. A total of 68 episodes of candidemia were evaluated. We found an average incidence of 2.23 episodes /1000 admissions and a 30-day mortality rate of 55.9%. The most prevalent species were Candida albicans (35.3%), Candida tropicalis (27.4%), Candida parapsilosis (21.6%) and Candida glabrata (11.8%). Higher mortality rates were observed in cases of candidemia due to C. albicans (61.1%) and C. glabrata (100%), especially when compared to C. parapsilosis (27.3%). Univariate analysis revealed some variables which significantly increased the probability of death: older age (P = 0.022; odds ratio [OR] = 1.041), severe sepsis (P < 0.001; OR = 8.571), septic shock (P = 0.035; OR = 3.792), hypotension (P = 0.003; OR = 9.120), neutrophilia (P = 0.046; OR = 3.080), thrombocytopenia (P = 0.002; OR = 6.800), mechanical ventilation (P = 0.009; OR = 8.167) and greater number of surgeries (P = 0.037; OR = 1.920). Multivariate analysis showed that older age (P = 0.040; OR = 1.055), severe sepsis (P = 0.009; OR = 9.872) and hypotension (P = 0.031; OR = 21.042) were independently associated with worse prognosis. There was no resistance to amphotericin B, micafungin or itraconazole and a low rate of resistance to fluconazole (5.1%). However, 20.5% of the Candida isolates were susceptible dose-dependent (SDD) to fluconazole and 7.7% to itraconazole. In conclusion, our results could assist in the adoption of strategies to stratify patients at higher risk for developing candidemia and worse prognosis, in addition to improve antifungal management.

The continuous changes in the aetiology and epidemiology of invasive candidiasis: from familiar Candida albicans to multiresistant Candida auris

Recent changes in the aetiology and epidemiology of invasive candidiasis have serious implications for current and future diagnosis, treatment and prognosis. The aim of the current review was to discuss the epidemiology of invasive candidiasis, the distribution of Candida species in different regions of the world, the medical concerns of the changing aetiology and the emergence of antifungal resistance. Overall burden of invasive candidiasis remains high, especially in vulnerable persons, such as the elderly, immunosuppressed or debilitated patients. Moreover, there is a progressive shift in the aetiology of invasive candidiasis from Candida albicans to other species of Candida, probably related to the increased use of azole drugs with a clear trend towards increased antifungal resistance. Finally, the emergence and rise of multiresistant species, such as Candida auris or Candida glabrata, is a major threat making necessary invasive candidiasis worldwide surveillances. These changes have serious implications for the diagnosis, treatment and prognosis of invasive candidiasis. Updated knowledge of the current local epidemiology of invasive candidiasis is critical for the clinical management.

Evaluation of Candida bloodstream infection and antifungal utilization in a tertiary care hospital

BACKGROUND

Candida bloodstream infections carry a significant mortality risk, justifying the importance of adequate antifungal therapy. This study describes trends in antifungal consumption using the Defined Daily Dose (DDD) and Days of Therapy (DOT) metrics, identifies the microbiological profile, the time to initiation of empirical therapy, the adjustment after positive blood culture results for Candida, and the impact on in-hospital mortality rate in patients with candidemia.

METHODS

An analysis of antifungal consumption from 2008 to 2016, and of candidemia cases from 2012 to 2016 was carried out in a private tertiary hospital.

RESULTS

A total of 11,273 admissions were identified with a prescription for at least one type of antifungal therapy. Fluconazole was the most prescribed antifungal drug in terms of general consumption. Through the DDD and DOT metrics, we observed that over time, there was an increase in the consumption of liposomal amphotericin B, micafungin and voriconazole. Candida albicans was the most isolated species in blood cultures. Regarding candidemia, we analyzed samples from 115 patients. Empirical therapy was started within 24 h of blood culture in 44.3% of the cases, and in 81.7% of the cases, the antifungal was deemed to be adequate based in antifungal susceptibility testing, both of which were not associated with the in-hospital mortality rate.

CONCLUSIONS

Our study reinforces the importance of monitoring the consumption of antifungal agents, which helps in proposing actions that lead to their rational use and, consequently, reduces the appearance of resistant strains.

Evaluation of two commercial methods for the susceptibility testing of Candida species: Vitek 2® and Sensititre YeastOne®

BACKGROUND

An increased incidence of fungal infections caused by Candida species, especially Candida glabrata and Candida krusei, which are less susceptible to azoles, has been observed. Standardized susceptibility testing is essential for clinical management and for monitoring the epidemiology of resistance.

AIMS

We evaluated the performance of two different susceptibility testing commercial methods, Vitek 2^® and Sensititre YeastOne^®, and compared them with the standard broth microdilution method (CLSI).

METHODS

A total of 80 isolates of several Candida species (Candida albicans, Candida parapsilosis complex, Candida tropicalis, C. glabrata and C. krusei) were selected for this study.

RESULTS

We analyzed the categorical agreement (CA) between the methods, stratifying the disagreements. The average CA between the methods was 96.3% for Vitek 2^® and 84% for Sensititre YeastOne^®. No very major errors were observed. Major errors and minor errors were found for all the isolates tested. With the azoles, both Vitek 2^® and Sensititre YeastOne^® had good and similar performance levels, except for C. tropicalis and C. krusei (Sensititre YeastOne^® showed low CA, 56.2%). With the echinocandins, both methods showed good performance for C. albicans, C. parapsilosis and C. tropicalis. However, we observed important discrepancies for C. krusei with caspofungin: Vitek 2^® had 100% CA while Sensititre YeastOne^® had only 25%. With amphotericin B, both Vitek 2^® and Sensititre YeastOne^® had good performance with high CA.

CONCLUSIONS

Despite the limited isolates tested, we concluded that both methods have good performance and are reliable for antifungal susceptibility testing. However, caspofungin activity against C. krusei and C. glabrata should be interpreted carefully when using Sensititre YeastOne^® because we observed a low CA.

Identification and antifungal susceptibility of Candida species isolated from the urine of patients in a university hospital in Brazil

The aim of this study was to identify Candida spp. isolated from candiduria episodes at a tertiary hospital in the Midwest region of Brazil, and to determine their susceptibility profiles to antifungal compounds. From May 2011 to April 2012, Candida spp. isolated from 106 adult patients with candiduria admitted to the University Hospital of the Federal University of Mato Grosso do Sul were evaluated. Both, species identification and susceptibility testing with fluconazole-FLC, voriconazole-VRC, and amphotericin B-AmB were carried out using the Vitek 2. To discriminate species of the C. parapsilosis complex, a RAPD-PCR technique using the RPO2 primer was performed. From the total of 106 isolates, 42 (39.6%) C. albicans and 64 (60.4%) Candida non-albicans (CNA) - 33 C. tropicalis, 18 C. glabrata, 5 C. krusei, 4 C. parapsilosis sensu stricto, 2 C. kefyr, 1 C. lusitaniae, and 1 C. guilliermondii were identified. All isolates were susceptible to AmB and VRC, whereas all C. glabrata isolates presented either resistance (5.6%) or dose-dependent susceptibility (94.4%) to FLC. The study of Candida spp. and their resistance profiles may help in tailoring more efficient therapeutic strategies for candiduria.

Prevalence, virulence factors and antifungal susceptibility of Candida spp. isolated from bloodstream infections in a tertiary care hospital in Brazil

Candida spp. are responsible for 80% of all systemic fungal infections and are associated with high mortality rates. This study characterised 79 bloodstream isolates of C. albicans, C. glabrata, C. orthopsilosis, C. parapsilosis and C. tropicalis from patients in a Brazilian hospital. The susceptibility to amphotericin B, caspofungin, fluconazole and voriconazole was determined; virulence factor production was assessed based on haemolysin, phospholipase and proteinase activities, and the patients' clinical characteristics were analysed. C. albicans was the predominant species (44%), followed by C. glabrata (19%), C. tropicalis (19%), C. parapsilosis (14%) and C. orthopsilosis (4%). The candidemia incidence was 1.52 per 1000 admissions, and the crude mortality rate was 52%. One C. albicans isolate was resistant to fluconazole and voriconazole. Moreover, 20.2%, 2.5% and 3.8% of the isolates exhibited dose-dependent susceptibility to fluconazole, voriconazole and caspofungin, respectively. In conclusion, although the C. glabrata incidence was higher than that usually described in Brazil, its increase was previously observed in studies conducted worldwide. Furthermore, the azole resistance of the C. albicans isolate could be due to previous exposure to these antifungals. These results highlight the importance of epidemiological studies and will facilitate an improved understanding of candidemia in the studied hospital.

Relationship between the Antifungal Susceptibility Profile and the Production of Virulence-Related Hydrolytic Enzymes in Brazilian Clinical Strains of Candida glabrata

Candida glabrata is a facultative intracellular opportunistic fungal pathogen in human infections. Several virulence-associated attributes are involved in its pathogenesis, host-pathogen interactions, modulation of host immune defenses, and regulation of antifungal drug resistance. This study evaluated the in vitro antifungal susceptibility profile to five antifungal agents, the production of seven hydrolytic enzymes related to virulence, and the relationship between these phenotypes in 91 clinical strains of C. glabrata. All C. glabrata strains were susceptible to flucytosine. However, some of these strains showed resistance to amphotericin B (9.9%), fluconazole (15.4%), itraconazole (5.5%), or micafungin (15.4%). Overall, C. glabrata strains were good producers of catalase, aspartic protease, esterase, phytase, and hemolysin. However, caseinase and phospholipase in vitro activities were not detected. Statistically significant correlations were identified between micafungin minimum inhibitory concentration (MIC) and esterase production, between fluconazole and micafungin MIC and hemolytic activity, and between amphotericin B MIC and phytase production. These results contribute to clarify some of the C. glabrata mechanisms of pathogenicity. Moreover, the association between some virulence attributes and the regulation of antifungal resistance encourage the development of new therapeutic strategies involving virulence mechanisms as potential targets for effective antifungal drug development for the treatment of C. glabrata infections.

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

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

Candidaemia due to Candida parapsilosis species complex at a hospital in Brazil: Clinical characteristics and antifungal susceptibility profile

BACKGROUND

Recent decades have seen a global emergence of candidaemia caused by non-Candida albicans Candida species, particularly the Candida parapsilosis complex.

AIMS

To evaluate the clinical features and antifungal susceptibility profiles of isolates belonging to the C. parapsilosis species complex in patients with candidaemia in a midwestern Brazilian tertiary-care teaching hospital.

METHODS

Yeast identification was performed using an automated Vitek 2 Compact system. PCR-RFLP was employed for species differentiation.

RESULTS

Five cases of infection by C. parapsilosis sensu stricto and two by Candida orthopsilosis were found. Of the seven cases, five were adult patients undergoing haemodialysis. The only isolate of C. parapsilosis sensu stricto resistant to fluconazole (MIC=8μg/ml) was obtained from a patient on a long-term regimen with this drug. This was the only patient who evolved to death.

CONCLUSIONS

Resistance to antifungal agents poses a therapeutic challenge, especially for non-C. albicans Candida species, and requires continuous monitoring using susceptibility tests because resistance in vitro can be predictive of treatment failure. In the present study, in vitro antifungal susceptibility proved consistent with clinical outcome.

First description of Candida nivariensis in Brazil: antifungal susceptibility profile and potential virulence attributes

This study evaluated the antifungal susceptibility profile and the production of potential virulence attributes in a clinical strain of Candida nivariensis for the first time in Brazil, as identified by sequencing the internal transcribed spacer (ITS)1-5.8S-ITS2 region and D1/D2 domains of the 28S of the rDNA. For comparative purposes, tests were also performed with reference strains. All strains presented low planktonic minimal inhibitory concentrations (PMICs) to amphotericin B (AMB), caspofungin (CAS), and voriconazole. However, our strain showed elevated planktonic MICs to posaconazole (POS) and itraconazole, in addition to fluconazole resistance. Adherence to inert surfaces was conducted onto glass and polystyrene. The biofilm formation and antifungal susceptibility on biofilm-growing cells were evaluated by crystal violet staining and a XTT reduction assay. All fungal strains were able to bind both tested surfaces and form biofilm, with a binding preference to polystyrene (p < 0.001). AMB promoted significant reductions (≈50%) in biofilm production by our C. nivariensis strain using both methodologies. This reduction was also observed for CAS and POS, but only in the XTT assay. All strains were excellent protease producers and moderate phytase producers, but lipases were not detected. This study reinforces the pathogenic potential of C. nivariensis and its possible resistance profile to the azolic drugs generally used for candidiasis management.

Epidemiology and Microbiologic Characterization of Nosocomial Candidemia from a Brazilian National Surveillance Program

Candidemia is a growing problem in hospitals all over the world. Despite advances in the medical support of critically ill patients, candidiasis leads to prolonged hospitalization, and has a crude mortality rate around 50%. We conducted a multicenter surveillance study in 16 hospitals distributed across five regions of Brazil to assess the incidence, species distribution, antifungal susceptibility, and risk factors for bloodstream infections due to Candida species. From June 2007 to March 2010, we studied a total of 2,563 nosocomial bloodstream infection (nBSI) episodes. Candida spp. was the 7^th most prevalent agent. Most of the patients were male, with a median age of 56 years. A total of 64 patients (46.7%) were in the ICU when candidemia occurred. Malignancies were the most common underlying condition (32%). The crude mortality rate of candidemia during the hospital admission was 72.2%. Non-albicans species of Candida accounted for 65.7% of the 137 yeast isolates. C. albicans (34.3%), Candida parapsilosis (24.1%), Candida tropicalis (15.3%) and Candida glabrata (10.2%) were the most prevalent species. Only 47 out of 137 Candida isolates were sent to the reference laboratory for antifungal susceptibility testing. All C. albicans, C. tropicalis and C. parapsilosis isolates were susceptible to the 5 antifungal drugs tested. Among 11 C. glabrata isolates, 36% were resistant to fluconazole, and 64% SDD. All of them were susceptible to anidulafungin and amphotericin B. We observed that C. glabrata is emerging as a major player among non-albicans Candida spp. and fluconazole resistance was primarily confined to C. glabrata and C. krusei strains. Candida resistance to echinocandins and amphotericin B remains rare in Brazil.

Mortality rates remain increasingly higher than that observed in the Northern Hemisphere countries, emphasizing the need for improving local practices of clinical management of candidemia, including early diagnosis, source control and precise antifungal therapy.

FREQUENCY OF Candida SPECIES IN A TERTIARY CARE HOSPITAL IN TRIANGULO MINEIRO, MINAS GERAIS STATE, BRAZIL

Infections by Candida species are a high-impact problem in public health due to their wide incidence in hospitalized patients. The goal of this study was to evaluate frequency, susceptibility to antifungals, and genetic polymorphism of Candida species isolated from clinical specimens of hospitalized patients. The Candida isolates included in this study were obtained from blood cultures, abdominal fluids, and central venous catheters (CVC) of hospitalized patients at the Clinical Hospital of the Federal University of Uberlândia during the period of July 2010 - June 2011. Susceptibility tests were conducted by the broth microdilution method. The RAPD-PCR tests used employed initiator oligonucleotides OPA09, OPB11, and OPE06. Of the 63 Candida isolates, 18 (28.5%) were C. albicans, 20 (31.7%) were C. parapsilosis complex species, 14 (22.2%) C. tropicalis, four (6.4%) C. glabrata, four (6.4%) C. krusei, two (3.3%) C. kefyr, and one (1.6%) C. lusitaniae. In vitro resistance to amphotericin B was observed in 12.7% of isolates. In vitroresistance to azoles was not detected, except for C. krusei. The two primers, OPA09 and OPB11, were able to distinguish different species. Isolates of C. albicans and C. parapsilosis complex species presented six and five clusters, respectively, with the OPA09 marker by RAPD-PCR, showing the genetic variability of the isolates of those species. It was concluded that members of the C. parapsilosis complex were the most frequent species found, and most isolates were susceptible to the antifungals amphotericin B, flucozanole, and itraconazole. High genetic polymorphisms were observed for isolates of C. albicans and C. parapsilosis complex species, mainly with the OPA09 marker.

Draft genome of a commonly misdiagnosed multidrug resistant pathogen Candida auris

Background

Candida auris is a multidrug resistant, emerging agent of fungemia in humans. Its actual global distribution remains obscure as the current commercial methods of clinical diagnosis misidentify it as C. haemulonii. Here we report the first draft genome of C. auris to explore the genomic basis of virulence and unique differences that could be employed for differential diagnosis.

Results

More than 99.5 % of the C. auris genomic reads did not align to the current whole (or draft) genome sequences of Candida albicans, Candida lusitaniae, Candida glabrata and Saccharomyces cerevisiae; thereby indicating its divergence from the active Candida clade. The genome spans around 12.49 Mb with 8527 predicted genes. Functional annotation revealed that among the sequenced Candida species, it is closest to the hemiascomycete species Clavispora lusitaniae. Comparison with the well-studied species Candida albicans showed that it shares significant virulence attributes with other pathogenic Candida species such as oligopeptide transporters, mannosyl transfersases, secreted proteases and genes involved in biofilm formation. We also identified a plethora of transporters belonging to the ABC and major facilitator superfamily along with known MDR transcription factors which explained its high tolerance to antifungal drugs.

Conclusions

Our study emphasizes an urgent need for accurate fungal screening methods such as PCR and electrophoretic karyotyping to ensure proper management of fungemia. Our work highlights the potential genetic mechanisms involved in virulence and pathogenicity of an important emerging human pathogen namely C. auris. Owing to its diversity at the genomic scale; we expect the genome sequence to be a useful resource to map species specific differences that will help develop accurate diagnostic markers and better drug targets.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1863-z) contains supplementary material, which is available to authorized users.

Draft genome of a commonly misdiagnosed multidrug resistant pathogen Candida auris

BACKGROUND

Candida auris is a multidrug resistant, emerging agent of fungemia in humans. Its actual global distribution remains obscure as the current commercial methods of clinical diagnosis misidentify it as C. haemulonii. Here we report the first draft genome of C. auris to explore the genomic basis of virulence and unique differences that could be employed for differential diagnosis.

RESULTS

More than 99.5 % of the C. auris genomic reads did not align to the current whole (or draft) genome sequences of Candida albicans, Candida lusitaniae, Candida glabrata and Saccharomyces cerevisiae; thereby indicating its divergence from the active Candida clade. The genome spans around 12.49 Mb with 8527 predicted genes. Functional annotation revealed that among the sequenced Candida species, it is closest to the hemiascomycete species Clavispora lusitaniae. Comparison with the well-studied species Candida albicans showed that it shares significant virulence attributes with other pathogenic Candida species such as oligopeptide transporters, mannosyl transfersases, secreted proteases and genes involved in biofilm formation. We also identified a plethora of transporters belonging to the ABC and major facilitator superfamily along with known MDR transcription factors which explained its high tolerance to antifungal drugs.

CONCLUSIONS

Our study emphasizes an urgent need for accurate fungal screening methods such as PCR and electrophoretic karyotyping to ensure proper management of fungemia. Our work highlights the potential genetic mechanisms involved in virulence and pathogenicity of an important emerging human pathogen namely C. auris. Owing to its diversity at the genomic scale; we expect the genome sequence to be a useful resource to map species specific differences that will help develop accurate diagnostic markers and better drug targets.

Synergistic effects of tacrolimus and azole antifungal compounds in fluconazole-susceptible and fluconazole-resistant Candida glabrata isolates

In vitro interaction between tacrolimus (FK506) and four azoles (fluconazole, ketoconazole, itraconazole and voriconazole) against thirty clinical isolates of both fluconazole susceptible and -resistant Candida glabrata were evaluated by the checkerboard microdilution method. Synergistic, indifferent or antagonism interactions were found for combinations of the antifungal agents and FK506. A larger synergistic effect was observed for the combinations of FK506 with itraconazole and voriconazole (43%), followed by that of the combination with ketoconazole (37%), against fluconazole-susceptible isolates. For fluconazole-resistant C. glabrata , a higher synergistic effect was obtained from FK506 combined with ketoconazole (77%), itraconazole (73%), voriconazole (63%) and fluconazole (60%). The synergisms that we observed in vitro , notably against fluconazole-resistant C. glabrata isolates, are promising and warrant further analysis of their applications in experimental in vivo studies.

Nosocomial bloodstream Candida infections in a tertiary-care hospital in South Brazil: a 4-year survey

The aims of this study were to evaluate the epidemiology of nosocomial candidemia in a tertiary hospital in South Brazil and the in vitro antifungal susceptibility of isolates. Blood strains from 108 patients were identified by PCR-based method. Some 30.5 % of candidemia were caused by Candida tropicalis, 28.7 % were due to Candida albicans, 24.1 % with Candida parapsilosis sensu stricto, 8.3 % with Candida glabrata sensu lato, 1.8 % involved Candida krusei and 6.6 % with other species. Candidemia was more common in intensive care unit settings (66 %). In vitro susceptibility to antifungal drugs was determined by a microdilution method; and new species-specific clinical breakpoints for fluconazole and voriconazole were applied. Overall susceptibility rates were 100 % for itraconazole, 91 % for fluconazole, 98 % for voriconazole and 99 % for amphotericin B. Fluconazole resistance was mostly among C. parapsilosis sensu stricto isolates (26.9 %). Most of the findings reported here agreed with epidemiological features common to other tertiary hospitals in Brazil; but also revealed some peculiarities, such as a high frequency of C. tropicalis associated with candidemia. Besides, high rate of fluconazole resistance among C. parapsilosis stricto sensu isolates was obtained when applying the new species-specific clinical breakpoints.

Prognostic factors and historical trends in the epidemiology of candidemia in critically ill patients: an analysis of five multicenter studies sequentially conducted over a 9-year period

PURPOSE

To describe temporal trends in the epidemiology, clinical management and outcome of candidemia in intensive care unit (ICU) patients.

METHODS

This study was a retrospective analysis of 1,392 episodes of candidemia in 647 adult ICU patients from 22 Brazilian hospitals. The characteristics of candidemia in these ICU patients were compared in two periods (2003-2007, period 1; 2008-2012, period 2), and the predictors of 30-day mortality were assessed.

RESULTS

The proportion of patients who developed candidemia while in the ICU increased from 44 % in period 1 to 50.9 % in period 2 (p = 0.01). Prior exposure to fluconazole before candidemia (22.3 vs. 11.6 %, p < 0.001) and fungemia due to Candida glabrata (13.1 vs. 7.8 %, p = 0.03) were more frequent in period 2, as was the proportion of patients receiving an echinocandin as primary therapy (18.0 vs. 5.9 %, p < 0.001). The 30-day mortality rate decreased from 76.4 % in period 1 to 60.8 % in period 2 (p < 0.001). Predictors of 30-day mortality by multivariate analysis were older age, period 1, treatment with corticosteroids and higher APACHE II score, while treatment with an echinocandin were associated with a higher probability of survival.

CONCLUSIONS

We found a clear change in the epidemiology and clinical management of candidemia in ICU patients over the 9-year period of the study. The use of echinocandins as primary therapy for candidemia appears to be associated with better outcomes.

Invasive candidosis: contrasting the perceptions of infectious disease physicians and intensive care physicians

INTRODUCTION

We analyze how infectious disease physicians perceive and manage invasive candidosis in Brazil, in comparison to intensive care unit specialists.

METHODS

A 38-question survey was administered to 56 participants. Questions involved clinicians’ perceptions of the epidemiology, diagnosis, treatment and prophylaxis of invasive candidosis. P < 0.05 was considered statistically significant.

RESULTS

The perception that candidemia not caused by Candida albicans occurs in less than 10% of patients is more commonly held by intensive care unit specialists (p=0.018). Infectious disease physicians almost always use antifungal drugs in the treatment of patients with candidemia, and antifungal drugs are not as frequently prescribed by intensive care unit specialists (p=0.006). Infectious disease physicians often do not use voriconazole when a patient’s antifungal treatment has failed with fluconazole, which also differs from the behavior of intensive care unit specialists (p=0.019). Many intensive care unit specialists use fluconazole to treat candidemia in neutropenic patients previously exposed to fluconazole, in contrast to infectious disease physicians (p=0.024). Infectious disease physicians prefer echinocandins as a fi rst choice in the treatment of unstable neutropenic patients more frequently than intensive care unit specialists (p=0.013). When candidemia is diagnosed, most infectious disease physicians perform fundoscopy (p=0.015), whereas intensive care unit specialists usually perform echocardiograms on all patients (p=0.054).

CONCLUSIONS

This study reveals a need to better educate physicians in Brazil regarding invasive candidosis. The appropriate management of this disease depends on more drug options being available in our country in addition to global coverage in private and public hospitals, thereby improving health care.

Breakthrough candidemia due to multidrug-resistant Candida glabrata during prophylaxis with a low dose of micafungin

We identified a case of breakthrough candidemia in a 25-year-old patient receiving micafungin prophylaxis (50 mg/day). Five Candida glabrata isolates were obtained from blood cultures and were classified as multidrug-resistant isolates, since all of them exhibited high MICs for echinocandin and azole drugs. A mutation (S663F) in hot spot 1 of the FKS2 gene was found in all five isolates. This mutation yielded a 1,3-β-D-glucan synthase enzyme with highly reduced sensitivities to echinocandin drugs.

Epidemiology of candidaemia and invasive candidiasis. A changing face

Invasive candidiasis is a leading cause of mortality. Candidaemia is the most common clinical presentation of invasive candidiasis but more that 30% of these infections do not yield positive blood cultures. Candida albicans remains the predominant aetiology, accounting for 50% of all cases. However, there has been an epidemiological shift in the last decades. Some species of Candida different to C. albicans have emerged as an important cause of severe candidaemia as they can exhibit resistance to fluconazole and other antifungal agents. Moreover, there is a different distribution of non C. albicans Candida species in relationship to patients' and hospital characteristics. Thus, Candida parapsilosis has been associated to candidaemia in neonates and young adults. This species usually has an exogenously origin and contaminates medical devices, causing central venous catheter-associated candidaemias. Candida glabrata, Candida tropicalis and Candida krusei are isolated in blood cultures from older patients (>65 years) with important risk factors, such as major abdominal surgery, solid tumours and haematologic malignancies, transplants, and/or prolonged treatment with corticoids. Moreover, important geographical differences in the distribution of the Candida species different to C. albicans causing invasive candidiasis have been reported: C. parapsilosis predominates in Australia, Latin America and Mediterranean countries of Africa, Asia and Europe. In contrast, C. glabrata has an important aetiological role in USA and Central and Northern Europe. Finally, an important and worrying issue is that mortality due to invasive candidiasis remains unacceptably high. 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).

Trafficking of phagocytic peritoneal cells in hypoinsulinemic-hyperglycemic mice with systemic candidiasis

Background

Candidemia is a severe fungal infection that primarily affects hospitalized and/or immunocompromised patients. Mononuclear phagocytes have been recognized as pivotal immune cells which act in the recognition of pathogens, phagocytosis, inflammation, polarization of adaptive immune response and tissue repair. Experimental studies have showed that the systemic candidiasis could be controlled by activated peritoneal macrophages. However, the mechanism to explain how these cells act in distant tissue during a systemic fungal infection is still to be elucidated. In the present study we investigate the in vivo trafficking of phagocytic peritoneal cells into infected organs in hypoinsulinemic-hyperglycemic (HH) mice with systemic candidiasis.

Methods

The red fluorescent vital dye PKH-26 PCL was injected into the peritoneal cavity of Swiss mice 24 hours before the intravenous inoculation with Candida albicans. After 24 and 48 hours and 7 days of infection, samples of the spleen, liver, kidneys, brain and lungs were submitted to the microbiological evaluation as well as to phagocytic peritoneal cell trafficking analyses by fluorescence microscopy.

Results

In the present study, PKH⁺ cells were observed in the peritoneum, kidney, spleen and liver samples from all groups. In infected mice, we also found PKH⁺ cells in the lung and brain. The HH condition did not affect this process.

Conclusions

In the present study we have observed that peritoneal phagocytes migrate to tissues infected by C. albicans and the HH condition did not interfere in this process.

Epidemiology of candidemia in Latin America: a laboratory-based survey

Background

The epidemiology of candidemia varies depending on the geographic region. Little is known about the epidemiology of candidemia in Latin America.

Methods

We conducted a 24-month laboratory-based survey of candidemia in 20 centers of seven Latin American countries. Incidence rates were calculated and the epidemiology of candidemia was characterized.

Results

Among 672 episodes of candidemia, 297 (44.2%) occurred in children (23.7% younger than 1 year), 36.2% in adults between 19 and 60 years old and 19.6% in elderly patients. The overall incidence was 1.18 cases per 1,000 admissions, and varied across countries, with the highest incidence in Colombia and the lowest in Chile. Candida albicans (37.6%), C. parapsilosis (26.5%) and C. tropicalis (17.6%) were the leading agents, with great variability in species distribution in the different countries. Most isolates were highly susceptible to fluconazole, voriconazole, amphotericin B and anidulafungin. Fluconazole was the most frequent agent used as primary treatment (65.8%), and the overall 30-day survival was 59.3%.

Conclusions

This first large epidemiologic study of candidemia in Latin America showed a high incidence of candidemia, high percentage of children, typical species distribution, with C. albicans, C. parapsilosis and C. tropicalis accounting for the majority of episodes, and low resistance rates.