Candida albicans skin abscess

Subcutaneous candidal abscess is a very rare infection even in immunocompromised patients. Some cases are reported when breakdown in the skin occurs, as bacterial cellulites or abscess, iatrogenic procedures, trauma and parenteral substance abuse. We describe a case of Candida albicans subcutaneous abscess without fungemia, which can be associated with central venous catheter.

An evaluation of manual and mechanical methods to identify Candida spp. from human and animal sources

To compare two yeast identification methods, i. e, the manual and the VITEK mechanical methods, 62 clinical samples from hemocultures and animal sources were analyzed. After identification as Candida yeasts by the VITEK method, the strains were recharacterized using manual assimilation methods and sugar fermentation tests. Our findings reveal 58% concurrent identification between the two methods for animal strains, and 51% for human hemoculture strains.

Enzymatic and hemolytic activities of Candida dubliniensis strains

Candida dubliniensis is an opportunistic yeast that has been recovered from several body sites in many populations; it is most often recovered from the oral cavities of human immunodeficiency virus-infected patients. Although extensive studies on epidemiology and phylogeny of C. dubliniensis have been performed, little is known about virulence factors such as exoenzymatic and hemolytic activities. In this study we compared proteinase, hyaluronidase, chondroitin sulphatase and hemolytic activities in 18 C. dubliniensis and 30 C. albicans strains isolated from AIDS patients. C. albicans isolates produced higher amounts of proteinase than C. dubliniensis (p < 0.05). All the tested C. dubliniensis strains expressed hyaluronidase and chondroitin sulphatase activities, but none of them were significantly different from those observed with C. albicans (p > 0.05). Hemolytic activity was affected by CaCl2; when this component was absent, we did not notice any significant difference between C. albicans and C. dubliniensis hemolytic activities. On the contrary, when we added 2.5 g% CaCl2, the hemolytic activity was reduced on C. dubliniensis and stimulated on C. albicans tested strains (p < 0.05).

Comparison between E-test and CLSI broth microdilution method for antifungal susceptibility testing of Candida albicans oral isolates

Thirty Candida albicans isolated from oral candidosis patients and 30 C. albicans isolated from control individuals were studied. In vitro susceptibility tests were performed for amphotericin B, fluconazole, 5-flucytosine and itraconazole through the Clinical and Laboratorial Standards Institute (CLSI) reference method and E test system. The results obtained were analyzed and compared. MIC values were similar for the strains isolated from oral candidosis patients and control individuals. The agreement rate for the two methods was 66.67% for amphotericin B, 53.33% for fluconazole, 65% for flucytosine and 45% for itraconazole. According to our data, E test method could be an alternative to trial routine susceptibility testing due to its simplicity. However, it can not be considered a substitute for the CLSI reference method.

Candida esophagitis: species distribution and risk factors for infection

Although Candida albicans is the main cause of fungal esophagitis, other species such as C. tropicalis, C. krusei and C. stellatoidea have also been implicated. Several studies have identified risk factors for C. albicans esophagitis. However, data for non-C. albicans species is still sparse. The aim of this study was to determine the etiology of Candida esophagitis in our medical centre over an 18-month period. Additionally, we aimed to investigate predisposing conditions for esophageal candidosis caused by different Candida species. A total of 21,248 upper gastroscopies were performed in Santa Casa Complexo Hospitalar between January 2005 and July 2006. The prevalence of Candida esophagitis was 0.74% (n = 158). C. albicans caused the vast majority of infections (96.2%), followed by C. tropicalis (2.5%), C. lusitaniae (0.6%) and C. glabrata (0.6%). There were 81 women (51.3%) and 77 men (48.7%). No case of mixed infection occurred. Concomitant oral candidosis was documented for 10.8% (n = 17). Most of cases (55.1%) involved outpatients. Around one fifth of patients in our cohort had no identifiable risk factors for esophageal candidosis (20.8%). Since nearly all infections were caused by C. albicans we were not able to determine risk factors for esophagitis caused by other Candida species.

Candida bloodstream infection: data from a teaching hospital in Mato Grosso do Sul, Brazil

The incidence of Candida bloodstream infection has increased over the past years. In the Center-West region of Brazil, data on candidemia are scarce. This paper reports a retrospective analysis of 96 cases of Candida bloodstream infection at a Brazilian tertiary-care teaching hospital in the state of Mato Grosso do Sul, from January 1998 to December 2006. Demographic, clinical and laboratory data were collected from medical records and from the hospital's laboratory database. Patients' ages ranged from three days to 92 years, with 53 (55.2%) adults and 43 (44.8%) children. Of the latter, 25 (58.1%) were newborns. The risk conditions most often found were: long period of hospitalization, utilization of venous central catheter, and previous use of antibiotics. Fifty-eight (60.4%) patients died during the hospitalization period and eight (13.7%) of them died 30 days after the diagnosis of candidemia. Candida albicans (45.8%) was the most prevalent species, followed by C. parapsilosis (34.4%), C. tropicalis (14.6%) and C. glabrata (5.2%). This is the first report of Candida bloodstream infection in the state of Mato Grosso do Sul and it highlights the importance of considering the possibility of invasive Candida infection in patients exposed to risk factors, particularly among neonates and the elderly.

Candida glabrata susceptibility to antifungals and phagocytosis is modulated by acetate

Candida glabrata is considered a major opportunistic fungal pathogen of humans. The capacity of this yeast species to cause infections is dependent on the ability to grow within the human host environment and to assimilate the carbon sources available. Previous studies have suggested that C. albicans can encounter glucose-poor microenvironments during infection and that the ability to use alternative non-fermentable carbon sources, such as carboxylic acids, contributes to the virulence of this fungus. Transcriptional studies on C. glabrata cells identified a similar response, upon nutrient deprivation. In this work, we aimed at analyzing biofilm formation, antifungal drug resistance, and phagocytosis of C. glabrata cells grown in the presence of acetic acid as an alternative carbon source. C. glabrata planktonic cells grown in media containing acetic acid were more susceptible to fluconazole and were better phagocytosed and killed by macrophages than when compared to media lacking acetic acid. Growth in acetic acid also affected the ability of C. glabrata to form biofilms. The genes ADY2a, ADY2b, FPS1, FPS2, and ATO3, encoding putative carboxylate transporters, were upregulated in C. glabrata planktonic and biofilm cells in the presence of acetic acid. Phagocytosis assays with fps1 and ady2a mutant strains suggested a potential role of FPS1 and ADY2a in the phagocytosis process. These results highlight how acidic pH niches, associated with the presence of acetic acid, can impact in the treatment of C. glabrata infections, in particular in vaginal candidiasis.

Differences in exoenzyme production and adherence ability of Candida spp. isolates from catheter, blood and oral cavity

Phospholipase and proteinase production and the ability of adhesion to buccal epithelial cells (BEC) of 112 Candida isolates originated from oral cavity of HIV infected patients and from blood and catheter of intensive care unit patients were investigated. The proteinase production was detected by inoculation into bovine serum albumin (BSA) agar and the phospholipase activity was performed using egg yolk emulsion. A yeast suspension of each test strain was incubated with buccal epithelial cells and the number of adherence yeast to epithelial cells was counted. A percentage of 88.1% and 55.9% of Candida albicans and 69.8% and 37.7% of non-albicans Candida isolates produced proteinase and phospholipase, respectively. Non-albicans Candida isolated from catheter were more proteolytic than C. albicans isolates. Blood isolates were more proteolytic than catheter and oral cavity isolates while oral cavity isolates produced more phospholipase than those from blood and catheter. C. albicans isolates from oral cavity and from catheter were more adherent to BEC than non-albicans Candida isolates, but the adhesion was not different among the three sources analyzed. The results indicated differences in the production of phospholipase and proteinase and in the ability of adhesion to BEC among Candida spp. isolates from different sources. This study suggests that the pathogenicity of Candida can be correlated with the infected site.

Differentiation of Candida dubliniensis from Candida albicans with the use of killer toxins

The aim of this study was to report the ability of killer toxins, previously used as biotyping techniques, as a new tool to differentiate C. albicans from C. dubliniensis. The susceptibility of C. albicans and C. dubliniensis to killer toxins ranged from 33.9 to 93.3% and from 6.67 to 93.3%, respectively.

In vitro synergism of simvastatin and fluconazole against Candida species

Systemic fungal infections are responsible for high mortality rates. Several species of fungi may be involved, but Candida spp. is the most prevalent. Simvastatin is used to lower cholesterol and also exhibits antifungal action. The aim of this study was to evaluate the synergistic action of simvastatin with fluconazole against strains of Candida spp. Susceptibility testing was performed according to protocol M27-A3, by broth microdilution method and the synergistic effect of simvastatin and fluconazole was calculated based on FICI (Fractional Inhibitory Concentration Index). Eleven strains were evaluated, and simvastatin showed a synergistic effect with fluconazole against 10 (91%) of the Candida spp. strains tested. Simvastatin may be a valuable drug in the treatment of systemic infections caused by Candida spp.

MOLECULAR TYPING OF Candida albicans ISOLATES FROM HOSPITALIZED PATIENTS

SUMMARYIntroduction: The majority of nosocomial fungal infections are caused by Candida spp. where C. albicans is the species most commonly identified. Molecular methods are important tools for assessing the origin of the yeasts isolated in hospitals.Methods: This is a study on the genetic profifiles of 39 nosocomial clinical isolates of C. albicans using two typing methods: random amplifified polymorphic DNA (RAPD) and microsatellite, two different primers for each technique were used.Results: RAPD provided 10 and 11 different profiles with values for SAB of 0.84 ± 0.126 and 0.88 ± 0.08 for primers M2 and P4, respectively. Microsatellite using two markers, CDC3 and HIS3, allowed the observation of six and seven different alleles, respectively, with combined discriminatory power of 0.91.Conclusions: Although genetic variability is clear, it was possible to identify high similarity, suggesting a common origin for at least a part of isolates. It is important to emphasize that common origin was proven from yeasts isolated from colonization (urine, catheter or endotracheal secretions) and blood culture from the same patient, indicating that the candidemia must have started from a site of colonization. The combination of RAPD and microsatellite provides a quick and efficient analysis for investigation of similarity among nosocomial isolates of C. albicans.

FUNGEMIA CAUSED BY Candida SPECIES IN A CHILDREN'S PUBLIC HOSPITAL IN THE CITY OF SÃO PAULO, BRAZIL: STUDY IN THE PERIOD 2007-2010

Candidemia remains a major cause of morbidity and mortality in the health care environment. The epidemiology of Candida infection is changing, mainly in relation to the number of episodes caused by species C. non-albicans. The overall objective of this study was to evaluate the frequency of yeasts of the genus Candida, in a four-year period, isolated from blood of pediatric patients hospitalized in a public hospital of the city of São Paulo, Brazil. In this period, yeasts from blood of 104 patients were isolated and, the identified species of Candida by phenotypic and genotypic methods were: C. albicans (39/104), C. tropicalis (25/104), C. parapsilosis (23/104), Pichia anomala (6/104), C. guilliermondii (5/104), C. krusei (3/104), C. glabrata (2/104) and C. pararugosa (1/104). During the period of the study, a higher frequency of isolates of C. non-albicans (63.55%) (p = 0.0286) was verified. In this study we verified the increase of the non-albicans species throughout the years (mainly in 2009 and 2010). Thus, considering the peculiarities presented by Candida species, a correct identification of species is recommended to lead to a faster diagnosis and an efficient treatment.

SUSCEPTIBILITY OF Candida spp. ISOLATED FROM BLOOD CULTURES AS EVALUATED USING THE M27-A3 AND NEW M27-S4 APPROVED BREAKPOINTS

The high mortality rates associated with candidemia episodes and the emergence of resistance to antifungal agents necessitate the monitoring of the susceptibility of fungal isolates to antifungal treatments. The new, recently approved, species-specific clinical breakpoints (SS-CBPs)(M27-S4) for evaluating susceptibility require careful interpretation and comparison with the former proposals made using the M27-A3 breakpoints, both from CLSI. This study evaluated the susceptibility of the different species of Candida that were isolated from candidemias based on these two clinical breakpoints. Four hundred and twenty-two isolates were identified and, among them, C. parapsilosis comprised 46.68%, followed by C. albicans (35.78%), C. tropicalis (9.71%), C. glabrata (3.55%), C. lusitaniae (1.65%), C. guilliermondii (1.65%) and C. krusei (0.94%). In accordance with the M27-A3 criteria, 33 (7.81%) non-susceptible isolates were identified, of which 16 (3.79%) were resistant to antifungal agents. According to SS-CBPs, 80 (18.95%) isolates were non-susceptible, and 10 (2.36%) of these were drug resistant. When the total number of non-susceptible isolates was considered, the new SS-CBPs detected 2.4 times the number of isolates that were detected using the M27-A3 interpretative criteria. In conclusion, the detection of an elevated number of non-susceptible species has highlighted the relevance of evaluating susceptibility tests using new, species-specific clinical breakpoints (SS-CBPs), which could impact the profile of non-susceptible Candida spp. to antifungal agents that require continuous susceptibility monitoring.

EFFECT OF HIGHLY ACTIVE ANTIRETROVIRAL THERAPY ON VAGINAL Candida spp. ISOLATION IN HIV-INFECTED COMPARED TO HIV-UNINFECTED WOMEN

 Vulvovaginal candidiasis (VVC) in HIV-infected women contributed to the impairment of their quality of life. The aim of this study was to evaluate the effect of highly active antiretroviral therapy (HAART) use on the vaginal Candida spp. isolation in HIV-infected compared to HIV-uninfected women. This cross-sectional study included 178 HIV-infected (HIV group) and 200 HIV-uninfected women (control) that were studied at the Specialized Assistance Service (SAE) for sexually transmitted diseases (STD)/AIDS of the city of Maringá, Brazil, from April 1 to October 30, 2011. The yeasts were isolated and identified by phenotypic and molecular methods. The in vitro antifungal susceptibility to fluconazole, itraconazole, nystatin and amphotericin B was tested by the reference microdilution method. Higher frequencies of total vaginal Candida spp. isolation were found in the HIV-infected group than in the control group. However, both groups showed a similar frequency of colonization and VVC. Although C. albicans was the most frequent and sensitive to azolics and polyenes in both HIV-infected and uninfected women, the emerging resistance of C. glabrata to amphotericin B in the HIV-infected women was observed. Although higher frequency of vaginal Candida spp. isolation had been observed in the HIV-infected than in HIV-uninfected women, colonization and VVC showed similar frequency in both groups, indicating that HAART appears to protect against vaginal colonization and VVC.

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.