Species and antifungal susceptibility profile of agents causing vulvovaginal candidiasis in a military population: a cross-sectional study.

Military women on active duty are exposed to constant physical and mental demands, which may predispose them to some infection risks, including vulvovaginal candidiasis (VVC), a pathology considered a global public health problem. To monitor the prevalent and emerging pathogens in VVC, this study aimed to evaluate the distribution of yeast species and their in vitro antifungal susceptibility profile. We studied 104 vaginal yeast specimens obtained during routine clinical examinations. The population was attended at the Medical Center of the Military Police, São Paulo, Brazil, and was divided into two groups: infected patients (VVC) and colonised patients. Species were identified by phenotypic and proteomic methods (MALDI-TOF MS) and susceptibility to eight antifungal drugs, including azoles, polyenes, and echinocandins, was determined using microdilution broth. Candida albicans stricto sensu was found to be the most frequently isolated species (55%), but we observed a considerable rate of other Candida species isolates (30%), including Candida orthopsilosis stricto sensu only in the infected group. There were also other rare genera such as Rhodotorula, Yarrowia, and Trichosporon (15%), of which Rhodotorula mucilaginosa was the most prevalent in both groups. Fluconazole and voriconazole had the highest activity against all species in both groups. Candida parapsilosis was the most susceptible species, except for amphotericin-B in the infected group. Of note, we observed unusual resistance in C. albicans. Our results have allowed us to compile an epidemiological database on the etiology of VVC to support the empirical treatment and improve the health care of military women.

Vulvovaginal candidiasis (VVC) is an infection caused by fungi, mainly Candida albicans. Our results show that fungi other than C. albicans can cause VVC. So, our findings may help to choose the most appropriate treatment, as some may be resistant, to improve the quality of life of military women.

Aspects related to biofilm production and antifungal susceptibility of clinically relevant yeasts of the genus Trichosporon.

Trichosporonosis corresponds to a systemic fungal disease that leads to high mortality rates and is frequently associated with medical devices. It affects immunosuppressed patients in particular and is strongly linked to acquired human immunodeficiency, organ and tissue transplants, and malignant hematologic diseases such as leukemia and lymphomas. Trichosporon infections have been increasingly reported worldwide; however, little information is available either about their characteristics or the causative microorganism. Thus, the aims of the present study were: to investigate 59 yeasts of the genus Trichosporon by verifying the biofilm formation capacity of isolates; to analyze the susceptibility patterns of planktonic cells against the antifungals fluconazole, itraconazole, amphotericin-B, voriconazole, and caspofungin by comparing European Committee for Antimicrobial Susceptibility Testing (EUCAST) broth microdilution technique with the commercial method Etest; and to assess the susceptibility patterns of biofilm cells (sessile) against the same antifungals through broth microdilution. The ability to form biofilm on the surface of polystyrene plates was noted for all isolates, and 54.3% of samples were considered strong producers. Comparison between the antifungal susceptibility techniques evidenced that Etest showed higher and discordant minimum inhibitory concentrations (MICs) from those obtained by the microdilution method, especially for fluconazole, itraconazole, and caspofungin. Considering the susceptibility of biofilms, most species had high MIC50 and MIC90 against the tested antifungals, showing 4-to-66-fold higher concentrations for amphotericin B and 2-to-33-fold greater concentrations for caspofungin. These results highlight the importance of further studies with Trichosporon spp. for comparison between laboratory findings and in vivo response, considering both the susceptibility tests and the behavior of biofilm cells against drugs.

This study investigated 59 isolates of the medically important yeast Trichosporon in relation to their ability to form biofilms and the susceptibility of biofilms to antifungal agents. All isolates were able to produce biofilms and biofilms showed lower antifungal susceptibility.

Investigation of fluconazole heteroresistance in clinical and environmental isolates of Cryptococcus neoformans complex and Cryptococcus gattii complex in the state of Amazonas, Brazil.

Heteroresistance, defined as the occurrence of apparently homogeneous subpopulations of microbial cells showing different levels of antimicrobial susceptibility is a problem that has been associated with therapeutical failure in cryptococcosis. The purpose of the study was an investigation on the level of heteroresistance to fluconazole (LHF) as observed in clinical and environmental C. neoformans/C. gattii complex species isolates from Amazonas State (AM), Brazil. A total of 45 isolates and 9 type strains were analyzed. The assessments comprised testing for minimal inhibitory concentrations (MICs), for LHFs, for the strains' capacity of adaptation to high fluconazole (FLC) concentrations above the LHF, and for the stability of the heteroresistance phenomenon. The mean MICs for clinical isolates of C. gattii (6.4 µg/ml) were higher than those observed for environmental C. gattii strains (1.7 µg/ml) and clinical (3.7 µg/ml) as well as environmental (1.5 µg/ml) C. neoformans isolates. The phenomenon of heteroresistance to FLC was recorded for all isolates. On average, the LHF (8-256 µg/ml) of the isolates was 16 times higher than the FLC MICs (0.5-16 µg/ml) and a proportion of 85% isolates showed LHFs ≥ 16 µg/ml, 40% even ≥ 32 µg/ml. According to the adaptation assay, a considerable number of isolates (58%) showed the capacity of adaptation to MICs even higher than the initially recorded LHF. After the adaptation experiment, the adaptative-LHF values (8-512 µg/ml) were about 60 times higher than the original MIC values. After nine subsequent passages in drug-free broth, the isolates had their adaptative-LHF reduced. However, the LHF did not revert to the initially measured level. Our findings challenge the clinical interpretation of the antifungal MIC testing and motivate future studies correlating the levels of heteroresistance and parameters like LHF and adaptative-LHF with cryptococcosis-associated morbidity and mortality. LAY SUMMARY: Cryptococcosis affects many people and is caused by fungi of the Cryptococcus neoformans/Cryptococcus gattii complexes. These agents appear to become more resistant to antifungals when exposed to increasing concentrations of antifungals due to a phenomenon called heteroresistance.

Early clinical and microbiological predictors of outcome in hospitalized patients with cryptococcal meningitis.

BACKGROUND: Cryptococcal meningitis causes high mortality in immunocompromised and immunocompetent patients. The objective of this study was to identify early predictors of clinical outcome, available at the first days of hospitalization, in patients with cryptococcal meningitis in a tertiary center in Brazil. METHODS: Ninety-six cases of cryptococcal meningitis with clinical, epidemiological and laboratory data, and identification and antifungal susceptibility of the strains were analyzed. Quantitative CSF yeast counts were performed by direct microscopic exam with a Fuchs-Rosenthal cell counting chamber using an institutional protocol. Univariable and multiple analyses using logistic regression were performed to identify predictors, available at the beginning of hospitalization, of in-hospital mortality. Moreover, we performed a secondary analysis for a composite outcome defined by hospital mortality and intensive care unit transfer. RESULTS: The species and the antifungal susceptibility were not associated with the outcomes evaluated. The variables significantly associated with the mortality were age (OR = 1.08, 95% CI 1.02-1.15), the cerebrospinal fluid (CSF) yeasts count (OR = 1.65, 95% CI 1.20-2.27), systemic arterial hypertension (OR = 22.63, 95% CI 1.64-312.91) and neurological impairment identified by computed tomography (OR = 41.73, 95% CI 3.10-561.65). At the secondary analysis, CSF yeast count was also associated with the composite outcome, in addition to the culture of Cryptococcus spp. from bloodstream and cerebral toxoplasmosis. The associations were consistent with survival models evaluated. CONCLUSIONS: Age and CSF yeast count were independently associated with in-hospital mortality of patients with cryptococcal meningitis but Cryptococcus species identification and antifungal susceptibility were not associated with the outcomes. Quantitative CSF yeast counts used in this study can be evaluated and implemented in other low and middle-income settings.

Comparing the phenotypic, genotypic, and proteomic identification of Trichosporon species: A globally emerging yeast of medical importance.

Trichosporon spp. are widely distributed in the nature, comprising species that inhabit different ecological niches and can be found in the water, soil, and body surface of animals and humans. Such microorganisms have been classically associated with superficial infections; however, in the last decades, they have also been related to disseminated infections in immunocompromised patients, behaving as opportunistic agents, which demands rapid and accurate species identification for efficient therapy. Concordance level between the traditional phenotypic method and the molecular technique (gold standard) in the identification of all 59 Trichosporon samples was 59.3%. Identification concordance between MALDI-TOF spectrometry and the molecular technique was 71.2%. No isolate of environmental origin was identifiable by MALDI-TOF mass spectrometry (MS), and 100% of such environmental isolates were discordant for IGS region sequencing and phenotypic characterization. Both comparisons evidenced greatest concordance in the identification of T. asahii. The species T. debeurmannianum, T. dermatis, T. venhuisii and T. insectorum were not properly identified by both MALDI-TOF MS and the phenotypic technique. MALDI-TOF MS, in particular, seems to be appropriate to investigate yeasts of the genus Trichosporon; however, database updates are still necessary, especially for species that are not common in the clinical routine. With the aim of helping understand the aspects involved in early and accurate diagnosis of infections caused by this opportunistic agent, the present study compared the phenotypic, molecular (IGS region) and mass-spectrometry (MALDI-TOF) identification of 59 yeasts of the genus Trichosporon which had clinical and environmental origin and were kept in a mycology collection.

The present study compared the phenotypic, genotypic, and mass-spectrometry (MALDI-TOF) identification of 59 yeasts of the genus Trichosporon. MALDI-TOF MS, in particular, seems to be appropriate to investigate this yeasts when compared to a molecular technique (gold standard).

Fungi in dialysis water and dialysate: occurrence, susceptibility to antifungal agents and biofilm production capacity.

The aim of this study was to investigate the occurrence of fungi in dialysis water and dialysate, in addition to evaluating the susceptibility to antifungals and the biofilm production capacity of isolated microorganisms. The samples were collected in three hemodialysis units in Bauru (Brazil), every 15 days (July 2017-June 2018) at post-reverse osmosis, reuse, and dialysate points. The fungi were isolated by spread plate on Sabouraud dextrose agar. Filamentous fungi were phenotypically identified and yeasts were subjected to molecular evaluation of the ITS region. Susceptibility test to antifungals was carried out by the broth microdilution method and biofilm production capacity was evaluated in microtiter plates using crystal violet staining. Fungi were isolated in 52/216 (24.1%) samples, with an average count of 16.3 (10-40) CFU/mL. Overall, 61 microorganisms were identified, with 54 (88.5%) filamentous fungi and 7 (11.5%) yeasts. The main genera included were Penicillium, Cladosporium, Scedosporium, Rhinocladiella, Fusarium, and Emmonsia. Most isolates showed high values of minimum inhibitory concentration for 5-flucytosine and fluconazole and 35/45 (77.8%) isolates were classified as strong producers of biofilm. In order to increase the safety of the dialysis process, the adoption of control measures and monitoring of fungi in hemodialysis fluids is suggested.

High genetic variability of clinical and environmental Cryptococcus gattii isolates from Brazil.

Among Cryptococcus gattii genotypes, VGII has gained pivotal relevance in epidemiological, clinical and genetic contexts due to its association with several outbreaks in temperate regions and due to the high variability of this genotype. The aim of this study was to compare 25 isolates of C. gattii from the Southeast region of Brazil with previously described isolates from other regions of the country and around the world. Among the 25 isolates, 24 were VGII and one was VGI. All of them were newly identified. Three new allele types (AT) (AT47 for the URA5 locus, AT56 for the LAC1 locus, and AT96 for the IGS1 region) were also described. Compared with other Brazilian isolates, those from the Southeast region presented the greatest haplotype diversity. In general, the regions presented different sequence types (STs), and only nine STs were found in more than one location. GoeBURST analysis showed two large groups among the Brazilian isolates. The largest group consists of 59 STs predominantly from the North and Northeast regions; the other large group includes 57 STs from the Southeast and Midwest regions. In a global context the South American isolates presented the highest genetic diversity (STs = 145, haplotype diversity (Hd) = 0.999 and π = 0.00464), while the African populations showed the lowest genetic diversity (STs = 3, Hd = 0.667 and π = 0.00225). These results confirm that the Brazilian C. gattii VGII population is highly diverse and reinforce the hypothesis of dispersion of this genotype from South America.

Evaluation of Vitek MS for Differentiation of Cryptococcus neoformans and Cryptococcus gattii Genotypes.

Cryptococcus neoformans and Cryptococcus gattii are the main pathogenic species of invasive cryptococcosis among the Cryptococcus species. Taxonomic studies have shown that these two taxa have different genotypes or molecular types with biological and ecoepidemiological peculiarities. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been proposed as an alternative method for labor-intensive methods for C. neoformans and C. gattii genotype differentiation. However, Vitek MS, one of the commercial MALDI-TOF MS instruments, has not been yet been evaluated for this purpose. Thus, we constructed an in-house database with reference strains belonging to the different C. neoformans (VNI, VNII, VNIII, and VNIV) and C. gattii (VGI, VGII, VGIII, and VGIV) major molecular types by using the software Saramis Premium (bioMérieux, Marcy-l'Etoile, France). Then, this new database was evaluated for discrimination of the different genotypes. Our in-house database provided correct identification for all C. neoformans and C. gattii genotypes; however, due to the intergenotypic mass spectral similarities, a careful postanalytic evaluation is necessary to provide correct genotype identification.

Yeast isolation and identification in water used in a Brazilian hemodialysis unit by classic microbiological techniques and Raman spectroscopy.

The use of poorly treated water in hemodialysis centers may lead to fungal contamination, which poses a serious threat to immunologically debilitated hemodialysis patients. This study aimed to isolate and identify yeast species in the water of a Brazilian hemodialysis center by using classic microbiological techniques and Raman spectroscopy. For 12 months, a total of 288 water samples were collected from different points of the hemodialysis treatment distribution center. One hundred and forty-six yeast species were isolated and identified in the samples that tested positive for the presence of yeasts such as Candida parapsilosis (100 isolates, or 68.50%), C. guilliermondii (17 isolates, or 11.65%), Rhodotorula mucilaginosa (23 isolates, or 15.75%), R. glutinis (three isolates, or 2.05%), and Trichosporon inkin (three isolates, or 2.05%). Yeast susceptibility to the antifungal fluconazole was also assayed. Only two C. guilliermondii isolates were resistant to fluconazole: the minimal inhibitory concentrations were higher than 64 µg/mL. The different yeast species present in the water of a Brazilian hemodialysis center call for more effective water disinfection procedures in this unit. Raman spectroscopy is an excellent tool to identify yeast species and is potentially applicable in routine water monitoring in hemodialysis units.

Infections Caused by Fusarium Species in Pediatric Cancer Patients and Review of Published Literature.

Fusarium species have emerged as responsible for a broad spectrum of infections, including superficial, locally invasive and disseminated ones, especially in the hospital environment. Since there are few reports of invasive and disseminated fusariosis in children, the aim of this study was to report four cases of nosocomial infection caused by this microorganism in children with cancer hospitalized in a public children's hospital located in Brazil. Two of these patients were female and two were male. All patients presented febrile neutropenia, while three patients had acute lymphocytic leukemia and one patient had Wilms' tumor as underlying disease. In two cases, fungi were isolated from blood and identified as Fusarium oxysporum species complex after phenotypic and genotypic studies, while in two other cases fungi were isolated from skin biopsies and identified as Fusarium solani species complex. One patient died 12 days after the onset of cutaneous lesions. All isolates, after susceptibility testing, presented high levels of minimum inhibitory concentration for itraconazole, voriconazole and amphotericin B. Considering the emergence of filamentous fungi as etiologic agents of nosocomial infections, health professionals should be aware of the problems these infections, especially fungal ones, may cause to debilitated patients.

Standardization of Semi-Quantitative Dot Blotting Assay-Application in the Diagnosis, Follow-Up, and Relapse of Paracoccidioidomycosis.

INTRODUCTION: This study standardized a semi-quantitative dot blotting assay (DB) and a quantitative real-time polymerase chain reaction (qPCR) to detect specific antibodies for Paracoccidioides brasiliensis and its DNA in PCM patients. METHODOLOGY: We evaluated 42 confirmed PCM patients upon admission using a serological double agar gel immunodiffusion test (DID), DB, and molecular tests (qPCR in total blood). The control groups included 42 healthy individuals and 37 patients with other infectious diseases. The serological progress during treatment was evaluated in eight patients, and there was a relapse diagnosis in ten patients using the Pb B.339 strain antigen. The cut-off points for the serological tests were determined by a receiver operator characteristic curve. RESULTS: The DB and DID tests showed similar accuracy, but the DB identified lower antibody concentrations. Cross-reactions were absent in the DB assay. In the relapse diagnoses, DB exhibited much higher sensitivity (90%) than DID (30%). CONCLUSIONS: A DB assay is easier and faster than a DID test to be performed; DB and DID tests show the same accuracy, while blood qPCR is not recommended in the diagnosis at the time of admission; cross-reactions were not observed with other systemic diseases; DB and DID tests are useful for treatment monitoring PCM patients; and a DB assay is the choice for diagnosing relapse. These findings support the introduction of semi-quantitative DB assays in clinical laboratories.

Aspergillus in the Indoor Air of Critical Areas of a Tertiary Hospital in Brazil.

Airborne Aspergillus spp. are critical pathogens that cause nosocomial infections in hospitals. Despite their importance, little is known about the distribution of Aspergillus species in the indoor air of hospitals in Brazil. We investigated Aspergillus spp. in the indoor air of critical areas in a tertiary hospital in Brazil. Air samples (n = 238) were collected from the intensive care unit (ICU), medical clinic unit (MCU), and urgency and emergency unit (UEU) using an air sampler (100 L/min). Of the 324 Aspergillus isolates, 322 were identified using phenotypic methods, and 37 were identified using DNA sequencing. Aspergillus spp. was grouped into five sections: Fumigati (29.3%), Nidulantes (27.8%), Nigri (27.5%), Flavi (11.7%), and Terrei (3.1%). The predominant species identified via sequencing were Aspergillus sydowii (n = 9), Aspergillus flavus (n = 7), and Aspergilus fumigatus (n = 6). The number of Aspergillus spp. and their sections varied according to the collection day. A. fumigatus was isolated more frequently during winter and in the ICU. This study is the first to demonstrate the diversity of airborne Aspergillus (saprophytic, allergenic, toxigenic, and potentially pathogenic) strains in a hospital located in the Midwest region of Brazil. It contributes to the knowledge of the diversity of cryptic species in the hospital environment.

In vitro susceptibility of environmental isolates of Exophiala dermatitidis to five antifungal drugs.

Several dematiaceous fungi frequently isolated from nature are involved in cases of superficial lesions to lethal cerebral infections. Antifungal susceptibility data on environmental and clinical isolates are still sparse despite the advances in testing methods. The objective of this study was to examine the activities of 5-flucytosine, amphotericin B, itraconazole, voriconazole and terbinafine against environmental isolates of Exophiala strains by minimum inhibition concentration (MIC) determination. The strains were obtained from hydrocarbon-contaminated soil, ant cuticle and fungal pellets from the infrabuccal pocket of attine gynes. Broth microdilution assay using M38-A2 reference methodology for the five antifungal drugs and DNA sequencing for fungal identification were applied. Terbinafine was the most active drug against the tested strains. It was observed that amphotericin B was less effective, notably against Exophiala spinifera, also studied. High MICs of 5-flucytosine against Exophiala dermatitidis occurred. This finding highlights the relevance of studies on the antifungal resistance of these potential opportunistic species. Our results also contribute to a future improvement of the standard methods to access the drug efficacy currently applied to black fungi.

Genotyping Analysis of Cryptococcus deuterogattii and Correlation with Virulence Factors and Antifungal Susceptibility by the Clinical and Laboratory Standards Institute and the European Committee on Antifungal Susceptibility Testing Methods.

Data about the relationship between their molecular types, virulence factors, clinical presentation, antifungal susceptibility profile, and outcome are still limited for Cryptococcus deuterogattii. This study aimed to evaluate the molecular and phenotypic characteristics of 24 C. deuterogattii isolates from the southeast region of Brazil. The molecular characterization was performed by multilocus sequence typing (MLST). The antifungal susceptibility profile was obtained according to CLSI-M27-A3 and EUCAST-EDef 7.1 methods. The virulence factors were evaluated using classic techniques. The isolates were divided into four populations. The molecular analysis suggests recombinant events in most of the groups evaluated. Resistance and susceptibility dose-dependent to fluconazole were evidenced in four isolates (16%) by EUCAST and in four isolates (16%) by CLSI methods. The agreement at ±two dilutions for both methods was 100% for itraconazole, ketoconazole, and voriconazole, 96% for amphotericin B, and 92% for fluconazole. Significant differences in virulence factor expression and antifungal susceptibility to itraconazole and amphotericin B were found. The mixed infection could be suggested by the presence of variable sequence types, differences in virulence factor production, and decreased antifungal susceptibility in two isolates from the same patient. The data presented herein corroborate previous reports about the molecular diversity of C. deuterogattii around the world.

Antifungal activity of liriodenine on clinical strains of Cryptococcus neoformans and Cryptococcus gattii species complexes.

Background: Cryptoccocal meningitis continues to present high incidence among AIDS patients. The treatment of choice is the synergistic combination of flucytosine (5-FC) with amphotericin B deoxycholate (AmBd) or its lipid formulations. However, 5-FC is unavailable in many countries and AmB demands hospitalization. The combination of AmB with the fungistatic fluconazole (FLC) or the use of high FLC daily doses alone became the choice. Nonetheless, sterilization of cerebrospinal fluid is delayed with FLC monotherapy, mainly with high fungal burden. These findings suggest the search for new antifungal compounds, such as liriodenine. Methods: Liriodenine antifungal activity was evaluated by three procedures: determining the minimum inhibitory concentration (MIC) on 30 strains of the Cryptococcus neoformans (C. neoformans) complex and 30 of the Cryptococcus gattii (C. gattii) complex, using EUCAST methodology and amphotericin B deoxycholate as control; performing the time-kill methodology in two strains of the C. neoformans complex and one of the C. gattii complex; and injury to cryptococcal cells, evaluated by transmission electron microscopy (TEM). Liriodenine absorption and safety at 0.75 and 1.50 mg.kg-1 doses were evaluated in BALB/c mice. Results: Liriodenine MICs ranged from 3.9 to 62.5 µg.mL-1 for both species complexes, with no differences between them. Time-kill methodology confirmed its concentration-dependent fungicidal effect, killing all the strains below the limit of detection (33 CFU.mL-1) at the highest liriodenine concentration (32-fold MIC), with predominant activity during the first 48 hours. Liriodenine induced severe Cryptococcus alterations - cytoplasm with intense rarefaction and/or degradation, injury of organelles, and presence of vacuoles. Liriodenine was better absorbed at lower doses, with no histopathological alterations on the digestive tract. Conclusion: The fungicidal activity confirmed by time-kill methodology, the intense Cryptococcus injury observed by TEM, the absorption after gavage administration, and the safety at the tested doses indicate that the liriodenine molecule is a promising drug lead for development of anticryptococcal agents.

A Rare Case of Aspergillus Mediastinitis After Coronary Artery Bypass Surgery: A Case Report and Literature Review.

BACKGROUND Mediastinitis is a serious complication after cardiac surgery; it is a deep sternal wound infection following sternotomy, with clinical evidence and/or microbiological involvement and sternal osteomyelitis. The most common pathogens are Staphylococcus spp (S. aureus), followed by gram-negative organisms. Establishing an etiological diagnosis of fungal mediastinitis is often a challenging issue, given the nonspecific clinical presentation. CASE REPORT A 74-year-old man was diagnosed with a three-vessel coronary artery disease in a university hospital. The patient had as clinical background hypertension, a body mass index (BMI) of 29.78 kg/m², and no diabetes mellitus. After an uneventful coronary artery bypass surgery, he presented clinical and radiological mediastinitis manifestations on the 9th postoperative day. He was treated with a range of antibiotics, with no clinical improvement until the 33rd postoperative day. Then, mediastinal fluid and biopsied tissue were collected and he was started on voriconazole due to growing Aspergillus spp. On the 93rd postoperative day, he had clinical improvement and, after several exams, was released from the hospital. We present the first report of Aspergillus fumigatus mediastinitis after cardiac surgery in Brazil, successfully treated with voriconazole. CONCLUSIONS Aspergillus infection should be considered in the differential diagnosis of mediastinitis after coronary surgery, especially in a clinical case of unexplained sepsis, negative blood culture, and no clinical improvement despite antibiotic therapy. This case report highlights that the mediastinal fluid and biopsy tissue culture can be useful for the diagnosis of fungal mediastinitis.

Modifications of antifungal sensibility testing as suggested by CLSI document M27-A4: proposal for using different culture medium and buffer.

A common strategy in antifungal susceptibility testing is the utilization of the standardized protocol based on the microbroth dilution assay approach as described by the Clinical Laboratory Standards Institute (CLSI) (M27-A4). One major problem for laboratories in resource-limited countries with this protocol arises from the use of expensive culture media like RPMI-1640 and 3-N-morpholinopropanesulfonic acid (MOPS) buffer. One approach of circumventing this problem in cases of economic need is the evaluation of alternative culture media and buffers. The overall goal of this work was to investigate the influence of modifications in the protocol M27-A4 on diagnostic reliability. We performed univariate analyses evaluating (1) 2 different culture media (YNB and modified SAB); (2) three different buffers (sodium bicarbonate, Tris-HCL, and phosphate), as well as the influence of inoculum concentration (102, 103, 104, 105 cells/mL), the influence of incubation time, and the influence of the assessment mode (visual, biological dye, and spectrophotometer). Our results suggested that (1) RPMI-1640 may be substituted by modified SAB and (2) MOPS buffer may be substituted by Tris-HCl buffer for defined analyses. By comparing the CLSI protocol and the alternative protocol proposed in the present study (modified SAB and Tris-HCl buffer) for the assessment of fluconazole susceptibility of eighteen yeasts (clinical isolates), similar results with both methodologies were recorded. We feel that this study should stimulate a discussion on the feasibility and evolution of the M27-A4 protocol in order to include pragmatic alternatives for resource-limited settings.

Lack of efficacy of echinocandins against high metabolic activity biofilms of Candida parapsilosis clinical isolates.

Candida parapsilosis produces biofilm, which colonizes catheters and other invasive medical devices that are manipulated by health care workers. In previous studies, C. parapsilosis in vitro biofilms have exhibited high resistance rates against conventional antifungals, but susceptibility to both echinocandins and lipid formulations of amphotericin B (lipid complex and liposomal). However, a recent study showed good activity of amphotericin B deoxycholate on the biomass of C. parapsilosis biofilms. Although moderate activity of echinocandins has been demonstrated against low metabolic activity biofilms of C. parapsilosis, few studies have analyzed the action of these drugs on high metabolic activity biofilms. Moreover, high biofilm-forming isolates have been associated with central venous catheter-related fungemia outbreaks and higher mortality rates. Therefore, it is relevant to verify the activity of the main antifungal drugs against high metabolic activity biofilms of C. parapsilosis. Our study aimed to evaluate the in vitro activity of amphotericin B deoxycholate, anidulafungin, caspofungin, and micafungin against high biofilm-forming and high metabolic activity clinical isolates of C. parapsilosis. Our results showed good activity of amphotericin B against C. parapsilosis biofilms, but none of the echinocandin drugs was effective. This suggests that amphotericin B deoxycholate may be a better choice than echinocandins for the treatment of biofilm-associated infections by C. parapsilosis, mainly in countries with insufficient health care resources to purchase lipid formulations of amphotericin B. These results warn of the possibility of persistent catheter-related candidemia caused by high biofilm-forming C. parapsilosis strains when treated with echinocandin drugs.

Antifungal Susceptibility of Candida Species Isolated from Horticulturists with Onychomycosis in Piauí, Brazil.

BACKGROUND: We aimed to assess susceptibility pattern of Candida species isolated from horticulturists with onychomycosis to four antifungal drugs and to compare the effectiveness of conventional identification methods with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). METHODS: This study was conducted in a community garden located in Teresina, State of Piauí, Brazil, in the year 2014. The samples were identified through phenotypic methods and per MALDI-TOF MS, being used PCR as definitive identification test. The susceptibility pattern to four antifungal drugs was determined according to Clinical and Laboratory Standards Institute (CLSI). RESULTS: Fourteen clinical isolates from seven different species were identified by the phenotypic method and by MALDI-TOF MS, with an observed concordance of 71.4% between the two methods. C. albicans (28.6%), C. parapsilosis (21.4%), C. guilliermondii and C. metapsilosis (both with 14.3%) were the most frequent species. With the exception of C. krusei, all species were sensitive to the tested antifungal. CONCLUSION: This is the first study of antifungal susceptibility of Candida in Piauí, Brazil. With the exception of C. krusei, no species showed resistance to the antifungal drugs used. This study suggests constants updates from the public databases used in MALDI-TOF MS to provide a rapid and accurate mycological diagnosis.

Proanthocyanidin polymeric tannins from Stryphnodendron adstringens are effective against Candida spp. isolates and for vaginal candidiasis treatment.

ETHNOPHARMACOLOGICAL RELEVANCE: The stem bark of Stryphnodendron adstringens (Mart.) Coville is popularly used as anti-inflammatory, astringent and in the treatment of wounds and vaginal infections. Several pharmacological activities have been scientifically proven by in vitro and in vivo experimental assays for antibacterial, antiviral, antiprotozoan, anti-inflammatory and antioxidant. AIM OF THE STUDY: We investigated whether proanthocyanidin polymeric tannins from the Stryphnodendron adstringens stem bark with antifungal activity against Candida albicans in vitro are also active against planktonic and biofilm cells of Candida non-albicans (CNA, including fluconazole-resistant isolates) and are capable of controlling Candida vaginitis in vivo. MATERIALS AND METHODS: A total of 46 clinical isolates and 5 reference Candida spp. strains were used in this study. The antifungal effects in vitro of tannins (F2 and sub-fraction F2.4) from S. adstringens stem bark were evaluated using a broth microdilution assay (for planktonic yeasts and biofilm dispersion cells) or by XTT assay (for biofilm sessile cells). For in vivo antifungal activity analysis, mice with vaginal infection by C. albicans or C. glabrata were treated with a topical gel containing F2 (alone or combined with oral fluconazole), and the vaginal histopathology and fungal burden (by CFU counts from vaginal homogenates) were analyzed. RESULTS: F2 and F2.4 inhibited the proliferation of planktonic cells of Candida spp., especially that of fluconazole- and/or amphotericin B-resistant isolates. F2 and F2.4 also inhibited the proliferation of Candida biofilm dispersion cells. Moreover, a gel containing F2 efficiently controlled vaginal infection by C. albicans and C. glabrata in mice, with no noticeable toxicity to vaginal tissue. CONCLUSIONS: Our data show that proanthocyanidin polymeric tannins obtained from S. adstringens have antifungal activity in vitro against C. albicans and CNA (including fluconazole-resistant isolates) and presented efficacy in the control of candidiasis in murine model. Therefore, these tannins have potential use in the treatment of vaginal candidiasis, representing interesting alternatives to current antifungals.