Evaluation of susceptibility and response in the surface of agents of surface mycoses (Trichophyton mentagrophytes; T. tonsurans) to antifungal drugs of interest in a medical clinic / Avaliação da susceptibilidade e resposta in vitro de agentes de micoses superficiais (Trichophyton mentagrophytes; T. tonsurans) à drogas antifúngicas de interesse em clínica médica

INTRODUCTION: The resistance of fungal species to drugs usually used in clinics is of great interest in the medical field. OBJECTIVE: To evaluate susceptibility and in vitro response of species of Trichophyton spp. to antifungal drugs of interest in clinical medicine. METHODS: 12 samples of clinical isolates from humans were used, nine of T. mentagrophytes and three of T. tonsurans. Susceptibility tests were performed according to the agar diffusion (AD) and broth microdilution (BM) methods. RESULTS: In the AD method, the species T. tonsurans presented a percentage of sensitivity of 33% in relation to amphotericin B and 66% to itraconazole, with 100% resistance to ketoconazole and fluconazole. T. mentagrophytes also showed 100% resistance to ketoconazole in this technique, with 11% sensitivity to ketoconazole, 22% to itraconazole and 22% of samples classified as sensitive dose dependent. In the MC method, the species T. tonsurans presented a sensitivity percentage of 66%, 55% and 33% in relation to ketoconazole, fluconazole and itraconazole, respectively. The T. mentagrophytes species presented sensitivity percentages of 11%, 11%, 33% and 55% for amphotericin B, itraconazole, ketoconazole and fluconazole, respectively. CONCLUSION: There was resistance in vitro of the species of T. mentagrophytes and T. tonsurans against the antifungal fluconazole and relative resistance against ketoconazole in the AD method. In BM, however, important percentages of sensitivity were observed for the two species analyzed in relation to the antifungals fluconazole and ketoconazole when compared to itraconazole and amphotericin B.

INTRODUÇÃO: A resistência de espécies fúngicas às drogas usualmente empregadas no meio clínico é motivo de grande interesse na área médica. OBJETIVO: Avaliar susceptibilidade e resposta in vitro de espécies de Trichophyton spp. a drogas antifúngicas de interesse em clínica médica. MÉTODOS: Foram utilizadas 12 amostras de isolados clínicos de humanos, sendo nove de T. mentagrophytes e três de T. tonsurans. Foram realizados testes de susceptibilidade segundo os métodos de difusão em ágar (DA) e microdiluição em caldo (MC). RESULTADOS: No método de DA, a espécie T. tonsurans apresentou percentual de sensibilidade de 33% em relação à anfotericina B e de 66% ao itraconazol, com 100% de resistência frente ao cetoconazol e ao fluconazol. A espécie T. mentagrophytes também apresentou 100% de resistência frente ao cetoconazol nesta técnica, com 11% de sensibilidade ao cetoconazol, 22% ao itraconazol e 22% das amostras classificadas como sensível dose dependente. No método de MC, a espécie T. tonsurans apresentou percentual de sensibilidade de 66%, 55% e 33% em relação ao cetoconazol, fluconazol e itraconazol, respectivamente. A espécie T. mentagrophytes apresentou percentuais de sensibilidade de 11%, 11%, 33% e 55% para anfotericina B, itraconazol, cetoconazol e fluconazol, respectivamente. CONCLUSÃO: Houve resistência in vitro das espécies do T. mentagrophytes e T. tonsurans frente ao antifúngico fluconazol e resistência relativa frente ao cetoconazol no método de DA. Na MC, no entanto, foram observados importantes percentuais de sensibilidade das duas espécies analisadas frente aos antifúngicos fluconazol e cetoconazol quando comparadas ao itraconazol e à anfotericina B.

ERG11 gene polymorphisms and susceptibility to fluconazole in candida isolates from diabetic and kidney transplant patients

Abstract INTRODUCTION: Candidiasis is the most frequent opportunistic mycosis in humans and can cause mortality, particularly in immunodeficient patients. One major concern is the increasing number of infections caused by drug-resistant Candidas trains, as these cannot be efficiently treated with standard therapeutics. The most common mechanism of fluconazole resistance in Candida is mutation of ERG11, a gene involved in the biosynthesis of ergosterol, a compound essential for cell integrity and membrane function. METHODS: Based on this knowledge, we investigated polymorphisms in the ERG11 gene of 3 Candida species isolated from immunocompromised and immunocompetent patients. In addition, we correlated the genetic data with the fluconazole susceptibility profile of the Candida isolates. RESULTS: A total of 80 Candida albicans, 8 Candida tropicalis and 6 Candida glabrata isolates were obtained from the saliva of diabetic, kidney transplant and immunocompetent patients. Isolates were considered susceptible to fluconazole if the minimum inhibitory concentration was lower than 8 μg/mL. The amino acid mutations F105L, D116E, K119N, S137L, and K128T were observed in C. albicans isolates, and T224C and G263A were found in C. tropicalis isolates. CONCLUSIONS: Despite the high number of polymorphisms observed, the mutations occurred in regions that are not predicted to interfere with ergosterol synthesis, and therefore are not related to fluconazole resistance.

A 12-year study of fungal infections in Rio Grande do Sul, southern Brazil

Background: The number of fungal infections has increased in recent years in Rio Grande do Sul (RS), Brazil. Epidemiological studies are important for proper control of infections. Aims: To evaluate the etiology of fungal infections in patients in RS, from 2003 to 2015. Methods: This is a retrospective and longitudinal study carried out at Mycology Department of Central Laboratory of RS; 13,707 samples were evaluated. The variables sex, age, site of infection, and etiologic agent were analyzed. Susceptibility of Candida to fluconazole was tested in samples collected in 2015from 51 outpatients. Results: Of the 13,707 samples, 840 cases (6.12%) of fungal infections were found and included in the analyses; female gender accounted for the 55.9% of the cases. The main fungus was Candida albicans (450 cases, 53.38%; p < 0.001). Onychomycosis was the most frequent infection in superficial mycoses. Systemic mycoses accounted for 54.05% of the cases, from which 68.8% occurred in males, mainly HIVpositive (33.11%), and the main etiologic agent in these cases was Cryptococcus neoformans (73.13%). Among 51 samples tested for susceptibility to fluconazole, 78.43% of Candida isolates were susceptible; 5.88% were susceptible in a dose-dependent manner, and 15.69% were resistant. Conclusions: C. albicans is a common cause of fungal infections in RS, accounting for half of the cases;resistance to antifungals was found in non-hospitalized patients. In addition, women seem to be moresusceptible to fungal infections than men, however men show more systemic mycoses than women. Thenails are the most common site of infection. (AU)

Clinical and laboratorial features of oral candidiasis in HIV-positive patients

Abstract INTRODUCTION We describe the clinical and laboratorial features of oral candidiasis in 66 HIV-positive patients. METHODS: Polymerase chain reaction-based techniques were performed for differentiation of Candida spp. isolated from patients at a public teaching hospital in Midwest Brazil. RESULTS: Oral lesions, mainly pseudomembranous, were significantly related to higher levels of immunosuppression. Of 45 Candida isolates, 66.7% were C. albicans. Most of the isolates were susceptible to the antifungal drugs tested. CONCLUSIONS: Oral lesions were associated with higher immunosuppression levels. Lower susceptibility to antifungals by non-albicans isolates supports the importance of surveillance studies using susceptibility tests to aid in the treatment.

Oral colonization by Candida species in HIV-positive patients: association and antifungal susceptibility study / Colonização oral por espécies de Candida em pacientes HIV positivo: estudo de associação e suscetibilidade antifúngica

ABSTRACT Objective To investigate antifungal susceptibility and factors associated with oral colonization by Candida species in HIV-positive patients. Methods A prospective study based on convenience sampling of subjects recruited from a pool of confirmed HIV-positive individuals seen at a specialty outpatient service in Rondonópolis, Mato Grosso, Brazil). Oral swabs were collected from 197 patients. Candida species were identified by standard microbiological techniques (phenotypic and molecular methods). Antifungal susceptibility was investigated using the broth microdilution method. Results A total of 101 (51.3%) patients were Candida spp carriers. Candida albicans was the most prevalent species (80%). Patients aged 45 to 59 years (Prevalence ratios: 1.90; 95%CI: 1.57-6.31) and 60 years or older (Prevalence ratios: 4.43; 95%CI: 1.57-34.18) were at higher risk of oral colonization by Candida species. Resistance to fluconazole and ketoconazole, or to itraconazole, corresponded to 1% and 4%, respectively. Conclusion Age (45 years or older) was the only factor associated with oral colonization by Candida . Low rates of antifungal resistance to azoles were detected in yeast isolates obtained from HIV-positive patients. Findings of this study may contribute to proper therapeutic selection for oral candidiasis in HIV-positive patients.

RESUMO Objetivo Investigar a suscetibilidade a antifúngicos e os fatores associados à colonização oral por espécies de Candida isoladas de pacientes HIV positivo. Métodos Estudo prospectivo realizado com amostragem por conveniência de indivíduos HIV positivo, acompanhados por um serviço de atendimento especializado da cidade de Rondonópolis, Mato Grosso, Brasil. Foram coletados swabs orais de 197 pacientes. As espécies de Candida foram identificadas por técnicas microbiológicas fenotípicas padrão e por método molecular. A suscetibilidade antifúngica foi determinada pelo método de microdiluição em caldo. Resultados Cento e um (51,3%) pacientes foram colonizados por Candida spp. Candida albicans foi a espécie mais prevalente (80%). Identificou-se um maior risco de colonização oral por espécies de Candida em pacientes com idade entre 45 e 59 anos (razão de prevalência: 1,90; IC95%: 1,57-6,31) e 60 anos ou mais (razão de prevalência: 4,43; IC95%: 1,57-34,18). A resistência ao fluconazol e ao cetoconazol foi de 1% cada e de 4% ao itraconazol. Conclusão O único fator associado à colonização oral por espécies de Candida foi ter 45 anos ou mais. Identificamos baixa taxa de resistência antifúngica aos azóis entre as leveduras isoladas de pacientes HIV positivo. Estes achados podem contribuir para selecionar o tratamento da candidíase oral em pacientes HIV positivos.

Variability in the clinical distributions of Candida species and the emergence of azole-resistant non-Candida albicans species in public hospitals in the Midwest region of Brazil

Abstract INTRODUCTION Incidence and antifungal susceptibility of Candida spp. from two teaching public hospitals are described. METHODS The minimum inhibitory concentrations of fluconazole, voriconazole, itraconazole, and amphotericin B were determined using Clinical Laboratory Standard Institute broth microdilution and genomic differentiation using PCR. RESULTS Of 221 Candida isolates, 50.2% were obtained from intensive care unit patients; 71.5% were recovered from urine and 9.1% from bloodstream samples. Candida parapsilosis sensu stricto was the most common candidemia agent. CONCLUSIONS We observed variations in Candida species distribution in hospitals in the same geographic region and documented the emergence of non-C. albicans species resistant to azoles.

Antifungal activity of synthetic antiseptics and natural compounds against Candida dubliniensis before and after in vitro fluconazole exposure

ABSTRACT INTRODUCTION: This study evaluated the susceptibilities of oral candidiasis-derived Candida albicans, fluconazole-resistant (FR) Candida dubliniensis, and fluconazole-susceptible (FS) C. dubliniensis to synthetic antiseptics [chlorhexidine gluconate (CHX), cetylpyridinium chloride (CPC), and triclosan (TRC)] and natural compounds (carvacrol, eugenol and thymol). METHODS: Susceptibility tests were performed based on the M27-A3 reference method. The fluconazole-resistant C. dubliniensis strains were obtained after prolonged in vitro exposure to increasing fluconazole concentrations. The geometric mean values for minimum inhibitory concentrations and minimum fungicidal concentrations were compared among the groups. RESULTS: Fluconazole-susceptible C. dubliniensis was more sensitive to CPC and TRC than FR C. dubliniensis and C. albicans were. However, eugenol and thymol were more active against FR C. dubliniensis. The fungicidal activities of CHX and TRC were similar for the three groups, and FR C. dubliniensis and C. albicans had similar sensitivities to CPC. CONCLUSIONS: The resistance of C. dubliniensis to fluconazole affects its sensitivity the synthetic antiseptics and natural compounds that were tested.

Antifungal activities of tacrolimus in combination with antifungal agents against fluconazole-susceptible and fluconazole-resistant Trichosporon asahii isolates

ABSTRACT The antifungal activity of tacrolimus in combination with antifungal agents against different fungal species has been previously reported. Here we report the in vitro interactions between tacrolimus and amphotericin B, fluconazole, itraconazole, and caspofungin against 30 clinical isolates of both fluconazole-susceptible and fluconazole-resistant Trichosporon asahii. For these analyses, we used the broth microdilution method based on the M27-A3 technique and checkerboard microdilution method. Tacrolimus showed no activity against T. asahii strains (minimal inhibitory concentrations, MICs > 64.0 µg mL−1). However, a larger synergistic interaction was observed by the combinations tacrolimus + amphotericin B (96.67%) and tacrolimus + caspofungin (73.33%) against fluconazole-susceptible isolates. Combinations with azole antifungal agents resulted in low rates of synergism for this group (fluconazole + tacrolimus = 40% and itraconazole + tacrolimus = 10%). Antagonistic interactions were not observed. For the fluconazole-resistant T. asahii group, all tested combinations showed indifferent interactions. The synergism showed against fluconazole-susceptible T. asahii isolates suggests that the potential antifungal activity of tacrolimus deserves in vivo experimental investigation, notably, the combination of tacrolimus with amphotericin B or caspofungin.

Susceptibility and molecular characterization of Candida species from patients with vulvovaginitis

Abstract Vulvovaginal candidiasis affects women of reproductive age, which represents approximately 15–25% of vaginitis cases. The present study aimed to isolate and characterize yeast from the patients irrespective of the presentation of clinical symptoms. The isolates were subjected to in vitro susceptibility profile and characterization by molecular markers, which intended to assess the distribution of species. A total of 40 isolates were obtained and identified through the CHROMagar, API20aux and by ITS and D1/D2 regions sequencing of DNAr gene. Candida albicans strains were genotyped by the ABC system and the isolates were divided into two genotypic groups. The identity of the C. albicans, C. glabrata, C. guilliermondii, C. kefyr and Saccharomyces cerevisiae isolates was confirmed by the multilocus analysis. The strains of Candida, isolated from patients with complications, were found to be resistant to nystatin but sensitive to fluconazole, amphotericin B and ketoconazole, as observed by in vitro sensitivity profile. The isolates from asymptomatic patients, i.e., the colonized group, showed a dose-dependent sensitivity to the anti-fungal agents, fluconazole and amphotericin B. However, the isolates of C. albicans that belong to distinct genotypic groups showed the same in vitro susceptibility profile.

First isolation of cryptococcus neoformans genotype VNI MAT-alpha from wood hollow trunks of hymenaea courbaril

Cryptococcal infection is transmitted by the inhalation of Cryptococcus spp. propagules. Information about the Cryptococcus species inhabiting plants might be clinically relevant due to the epidemiological role of these habitats as possible sources of human infection. The aim of this study was to increase the knowledge about the environmental occurrence of cryptococcosis agents. Hollow tree vegetal debris of nine plant species was sampled quarterly over a 12-month period. Melanized colonies were screened for Cryptococcus neoformans and C. gattii by biochemical tests, followed by URA5-RFLP molecular analysis, M13 fingerprinting assays, and mating-typing with the specific a and α primers. The susceptibility to fluconazole of all of the confirmed species colonies was determined using the AFST-EUCAST broth dilution method. We found that the typical Brazilian flora tree Hymenaea courbaril yielded a high cryptococcal burden (median, 10(2) CFU/g) during the summer, autumn and winter seasons. C. neoformans VNI molecular type MAT alpha was identified in all of the samples. The fingerprinting analyses showed great molecular variability with no correlation with the susceptibility profile to fluconazole (MIC range 4 to ≥64 mg/l). To our knowledge, this study is the first describing the association between C. neoformans and Hymenaea courbaril. These observations extend the known geographic distribution of and substantiate a new urban environmental niche for C. neoformans and also emphasize the genetic diversity of the environmental C. neoformans VNI molecular type isolates.

Antifungal susceptibility of clinical and environmental Cryptococcus neoformans and Cryptococcus gattii isolates in Jabalpur, a city of Madhya Pradesh in Central India

In this study, we present antifungal susceptibility data of clinical and environmental isolates of Central Indian Cryptococcus neoformans (Serotype A, n = 8 and n = 50 respectively) and Cryptococcus gattii (Serotype B, n = 01 and n = 04 respectively). Susceptibilities to fluconazole, itraconazole and ketoconazole were determined by using NCCLS broth micro-dilution methodology. The total number of resistant strains for fluconazole in case of C. neoformans and C. gattii showed a significant difference by using chi-square test (p < 0.05*), while considering fisher's exact p value was nonsignificant (p > 0.05). However, the total number of resistant strains for itraconazole and ketoconazole was not found statistically significant. A comparison of geometric means of clinical and environmental strains of C. gattii and C. neoformans was not found statistically significant using student ‘t’ test (p value > 0.05 NS). Though less, the antifungal data obtained in this study suggests that primary resistance among environmental and clinical isolates of C. neoformans and C. gattii against tested antifungal was present and C. gattii comparatively was less susceptible than C. neoformans var. grubii isolates to fluconazole than to itraconazole and ketoconazole. A continuous surveillance of antifungal susceptibility of clinical and environmental isolates of C. neoformans and C. gattii is desirable to monitor the emergence of any resistant strains for better management of cryptococcosis patients.

Simvastatin inhibits planktonic cells and biofilms ofCandida and Cryptococcusspecies

ABSTRACTThe antifungal activity of some statins against different fungal species has been reported. Thus, at the first moment, the in vitro antifungal activity of simvastatin, atorvastatin and pravastatin was tested againstCandida spp. and Cryptococcus spp. Then, in a second approach, considering that the best results were obtained for simvastatin, this drug was evaluated in combination with antifungal drugs against planktonic growth and tested against biofilms ofCandida spp. and Cryptococcus spp. Drug susceptibility testing was performed using the microdilution broth method, as described by the Clinical and Laboratory Standards Institute. The interaction between simvastatin and antifungals against planktonic cells was analyzed by calculating the fractional inhibitory concentration index. Regarding biofilm susceptibility, simvastatin was tested against growing biofilm and mature biofilm of one strain of each tested yeast species. Simvastatin showed inhibitory effect against Candida spp. andCryptococcus spp. with minimum inhibitory concentration values ranging from 15.6 to 1000 mg L-1 and from 62.5 to 1000 mg L-1, respectively. The combination of simvastatin with itraconazole and fluconazole showed synergism against Candidaspp. and Cryptococcus spp., while the combination of simvastatin with amphotericin B was synergistic only againstCryptococcus spp. Concerning the biofilm assays, simvastatin was able to inhibit both growing biofilm and mature biofilm ofCandida spp. and Cryptococcus spp. The present study showed that simvastatin inhibits planktonic cells and biofilms ofCandida and Cryptococcus species.

Distribución de especies y susceptibilidad antifúngica de Candida spp. causantes de micosis superficiales. Coro, estado Falcón, Venezuela / Species distribution and antifungal susceptibility of Candida spp. causing superficial mycosis. Coro, Falcon state, Venezuela.

Las especies de Candida distintas a C. albicans se describen con frecuencia como agentes causales de micosis superficial y presentan una mayor resistencia al tratamiento con los azoles. Con la finalidad de determinar la distribución de especies y la susceptibilidad antifúngica in vitro de Candida spp., se realizó un estudio ambispectivo donde se analizaron 18 aislados de levaduras obtenidas de muestras de pacientes con diagnóstico de micosis superficial. La identificación taxonómica se realizó mediante la visualización de las características macroscópicas de crecimiento en agar cromogénico y por métodos convencionales. La susceptibilidad a fluconazol y voriconazol se evaluó por el método de difusión en disco. El 88,8% de los aislados provenía de muestras de uñas. C. parapsilosis fue la especie más frecuente, seguida de C. tropicalis, C. albicans y C. krusei, lo cual confirmó el predominio de especies no albicans como causa de micosis superficial. El patrón de susceptibilidad a fluconazol y voriconazol fue similar: todos los aislados de C. parapsilosis y C. albicans resultaron sensibles, mientras que el 83,3% de C. tropicalis mostró sensibilidad a ambos antifúngicos. C. krusei, especie resistente a fluconazol, presentó sensibilidad intermedia al voriconazol. El uso de agar cromogénico permitió detectar infecciones mixtas en muestras de uñas, involucrando en uno de los casos a Candid spp. y C.tropicalis, esta última con resistencia tanto a fluconazol como a voriconazol. Los resultados obtenidos demuestran la importancia de la identificación de especies y la realización de pruebas de susceptibilidad con el fin de evitar fracasos terapéuticos en micosis superficiales. Autor de correspondencia: Leyla Humbría-García. Laboratorio de Micología

Candida species other than C. albicans are often described as causative agents of superficial mycosis and are more resistant to treatment with azoles. In order to determine the distribution of species and in vitro antifungal susceptibility of Candida spp., one ambispective study, which analyzed 18 yeast isolates obtained from samples from patients diagnosed with superficial mycosis, was performed. Taxonomic identification was performed by macroscopic visualization of the growth characteristics in chromogenic agar and by conventional methods. The susceptibility to fluconazole and voriconazole was evaluated by the disc diffusion method. Most of the isolates (88.8%), came from nail samples. C. parapsilosis was the most common species, followed by C. tropicalis, C. albicans and C. krusei, which confirmed the prevalence of non-albicans species as a cause of superficial mycoses. The pattern of susceptibility to fluconazole and voriconazole was similar: all isolates of C. parapsilosis and C. albicans were susceptible, while 83.3% of C. tropicalis showed sensitivity to both antifungals. C. krusei, fluconazole-resistant species showed intermediate susceptibility to voriconazole. The use of chromogenic agar allowed to detect mixed infections in nail samples, involving Candida spp. and C. tropicalis in one case, the latter with resistance to both fluconazole and voriconazole. The results demonstrate the importance of species identification and susceptibility testing to avoid therapeutic failures in superficial mycoses.

Impact of brief exposure to antifungal agents on the post-antifungal effect and hemolysin activity of oral Candida albicans

AbstractPost-antifungal effect (PAFE) of Candida and its production of hemolysin are determinants of candidal pathogenicity. Candida albicans is the foremost aetiological agent of oral candidosis, which can be treated with polyene, azole, and echinocandin antifungals. However, once administered, the intraoral concentrations of these drugs tend to be subtherapeutic and transient due to the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, Candidamay undergo a brief exposure to antifungal drugs.Objective Therefore, the PAFE and hemolysin production of oral C. albicans isolates following brief exposure to sublethal concentrations of the foregoing antifungals were evaluated.Material and Methods A total of 50 C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sublethal concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for 60 min. Thereafter, the drugs were removed and the PAFE and hemolysin production were determined by previously described turbidometric and plate assays, respectively.Results Nystatin, amphotericin B, caspofungin and ketoconazole induced mean PAFE (hours) of 2.2, 2.18, 2.2 and 0.62, respectively. Fluconazole failed to produce a PAFE. Hemolysin production of these isolates was suppressed with a percentage reduction of 12.27, 13.47, 13.33, 8.53 and 4.93 following exposure to nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole, respectively.Conclusions Brief exposure to sublethal concentrations of antifungal drugs appears to exert an antifungal effect by interfering with the growth as well as hemolysin production of C. albicans.

FREQUENCY OF Candida SPECIES IN A TERTIARY CARE HOSPITAL IN TRIANGULO MINEIRO, MINAS GERAIS STATE, BRAZIL / Frequência de espécies de Candida em hospital terciário do Triângulo Mineiro, Minas Gerais, Brasil

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 vitro resistance 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.

As infecções causadas por espécies de Candida são problema de grande impacto para a saúde pública, devido à alta incidência em pacientes hospitalizados e como causa de mortalidade. O presente estudo teve como objetivo avaliar a frequência de Candida spp. isoladas de pacientes hospitalizados, assim como a sensibilidade aos antifúngicos e o polimorfismo genético por RAPD-PCR. Os microrganismos incluíram isolados de hemocultura, líquido abdominal e ponta de cateter venoso central de pacientes internados no Hospital de Clínicas da Universidade Federal de Uberlândia, região do Triângulo Mineiro, Minas Gerais, Brasil, no período de julho de 2010-junho de 2011. Os testes de sensibilidade aos antifúngicos foram realizados por microdiluição em caldo e na análise por RAPD-PCR foram utilizados os oligonucleotídeos OPA09, OPB11, e OPE06. Dos 63 isolados, 18 (28,5%) foram C. albicans, 20 (31,7%) C. parapsilosis, 14 (22,2%) C. tropicalis, quatro (6,4%) C. glabrata, quatro (6,4%) C. krusei, dois (3,3%) C. kefyr, e um (1,6%) C. lusitaniae. Resistência in-vitro à anfotericina B foi observada em 12,7% dos isolados. Não foi observada resistência in-vitro aos azólicos, exceto para os isolados de C. krusei. Os oligonucleotídeos OPA09 e OPB11 possibilitaram distinguir diferentes espécies. Isolados de C. albicans apresentaram seis clusters e o complexo C. parapsilosis, cinco clusters, com o iniciador OPA09, por RAPD-PCR, mostrando a variabilidade genética daquelas espécies. Conclui-se que o complexo C. parapsilosis foi a espécie mais frequente, e a maioria dos isolados foi sensível in vitro aos antifúngicos testados. Alto polimorfismo genético foi observado para os isolados de C. albicans e complexo C. parapsilosis, principalmente com o oligonucleotídeo OPA09.

Nosocomial candidiasis in Rio de Janeiro State: Distribution and fluconazole susceptibility profile

One hundred and forty-one Candida species isolated from clinical specimens of hospitalized patients in Rio de Janeiro, Brazil, during 2002 to 2007, were analized in order to evaluate the distribution and susceptibility of these species to fluconazole. Candida albicans was the most frequent species (45.4%), followed by C. parapsilosis sensu lato (28.4%), C. tropicalis (14.2%), C. guilliermondii (6.4%), C. famata (2.8%), C. glabrata (1.4%), C. krusei (0.7%) and C. lambica (0.7%). The sources of fungal isolates were blood (47.5%), respiratory tract (17.7%), urinary tract (16.3%), skin and mucous membrane (7.1%), catheter (5.6%), feces (2.1%) and mitral valve tissue (0.7%). The susceptibility test was performed using the methodology of disk-diffusion in agar as recommended in the M44-A2 Document of the Clinical and Laboratory Standards Institute (CLSI). The majority of the clinical isolates (97.2%) was susceptible (S) to fluconazole, although three isolates (2.1%) were susceptible-dose dependent (S-DD) and one of them (0.7%) was resistant (R). The S-DD isolates were C. albicans, C. parapsilosis sensu lato and C. tropicalis. One isolate of C. krusei was resistant to fluconazole. This work documents the high susceptibility to fluconazole by Candida species isolated in Rio de Janeiro, Brazil.

Effects of the association of antifungal drugs on the antimicrobial action of endodontic sealers

This in vitro study aimed to determine the susceptibility of oral specimens and ATCC lineages of Candida albicans for five endodontic sealers, which were pure and associated with two antifungal drugs, and to analyze their effect on the physical properties. For this purpose, 30 lineages of C. albicans, collected from the oral cavity of patients assisted at the endodontics clinic of the Universidade Sagrado Coração, were analyzed. Yeasts susceptibility to the sealers was tested by diffusion on agar plates. Physical properties were evaluated according to the ADA specification no. 57. The pure versions of the Sealer 26, AH Plus, Endofill, Fillapex, and Sealapex demonstrated antifungal activity, with Endofill presenting the greatest inhibition zones. All cements, except for Endofill, had their antifungal actions enhanced by addition of ketoconazole and fluconazole (p < 0.05), and the AH Plus presented the best antifungal activity. The addition of antifungal drugs did not interfere with the setting time and flowability of the sealers. It was concluded that the addition of antifungals to endodontic sealers enhanced the antimicrobial action of most cements tested without altering their physical properties.

Antifungal activity of propolis against Candidaspecies isolated from cases of chronic periodontitis

This research evaluated the fungistatic and fungicidal activities of red propolis alcoholic extract (RPAE) against different Candida species isolated from chronic periodontitis cases, and compared with chlorhexidine (CHX). Nineteen samples of Candida species (C. albicans [n = 12], C. tropicalis [n = 5] andC. glabrata[n = 2]) isolated from chronic periodontitis cases were analyzed. The fungistatic and fungicidal activity of both RPAE and CHX were evaluated using fluconazole and C. parapsilosis (ATCC 6258) as a control. Fungistatic activity was analyzed based on the Clinical and Laboratory Standards Institute (CLSI) reference procedure to determine the minimum inhibitory concentrations. Fungicidal activity was established according to the absence of fungal growth on Sabouraud Dextrose Agar medium. The fungistatic and fungicidal activities of RPAE were observed, respectively, at 32-64 μg/mL and 64-512 μg/mL for C.albicans, 64 μg/mL and 64-256 μg/mL for C. glabrata, and 32-64 μg/mL and 64 µg/mL for C. tropicalis. CHX fungistatic activity was observed at concentrations of 0.003-1.92 µg/mL for C. albicans, 1.92 µg/mL for C. glabrata, and 0.03-1.92 µg/mL for C. tropicalis. Fluconazole fungistatic activity ranged between 1-64 μg/mL, and fungicidal activity occurred at 8-64 μg/mL, for the threeCandida species analyzed. All the Candidaspecies were susceptible to RPAE antifungal activity, but five samples ofC.albicans, one ofC.tropicalis and one ofC.glabrata were resistant to fluconazole antifungal activity. CHX showed fungistatic activity against all the Candida species analyzed. The antifungal potential of these substances suggests that they can be applied as an alternative treatment for diseases affected by these species.

Caracterización de los mecanismos de resistencia a azoles en aislados clínicos chilenos de Candida albicans / Characterization of azole resistance mechanisms in Chilean clinical isolates of Candida albicans

Introduction: The commensal yeast Candida albicans, can cause superficial or systemic candidiasis in susceptible hosts. In Chile, azole antifungals are the most widely used drugs in the treatment of candidiasis. In a previous study performed at our center, 2.1 and 1.6% of clinical isolates of C. albicans were found to be resistant to fluconazole and voriconazole, respectively. Objective: To characterize the resistance mechanisms involved in azoles resistance in Chilean clinical isolates. Methodology: Eight resistant, nine susceptible-dose dependent (SDD) and 10 susceptible strains (n: 27) were selected according to the Clinical Laboratory Standards Institute (CLSI) M27-S3 criteria, from vaginal and urine samples. Mutations in the 408-488 region of the ERG11 gene were studied by sequencing, and the relative expression of ERG11 gene and efflux pump genes CDR1, CDR2 and MDR1, was evaluated by quantitative real-time PCR (q-PCR). Results: No mutations were detected in the ERG11 gene and its overexpression was found only in 12.5% of the resistant strains (1/8). The most prevalent mechanism of resistance was the over-expression of efflux pumps (62.5%; 5/8). Conclusion: The study of the expression of efflux pumps by q-PCR could be a useful diagnostic tool for early detection of azole resistance in C. albicans.

Introducción: Candida albicans es una levadura comensal capaz de causar una infección oportunista en hospederos susceptibles denominada candidiasis, que puede ser superficial o sistémica. En Chile, los antifúngicos más utilizados para el tratamiento de las candidiasis son los azoles. En un estudio previo en nuestro centro, se detectó que 2,1 y 1,6% de cepas clínicas de C. albicans fueron resistentes a fluconazol y voriconazol, respectivamente. Objetivo: Caracterizar los mecanismos de resistencia involucrados en la resistencia a azoles en cepas clínicas chilenas. Metodología: Según los criterios del Clinical Laboratory Standards Institute (CLSI) M27-S3, se seleccionaron ocho cepas resistentes, nueve cepas susceptibles dosis dependiente (SDD) y 10 cepas sensibles (n: 27), aisladas de flujo vaginal y orina. Se evaluó la presencia de mutaciones en la región 408-488 del gen ERG11 por secuenciación y la expresión relativa del gen ERG11 y de los genes de bombas de eflujo CDR1, CDR2 y MDR1 por RPC en tiempo real cuantitativa (q-PCR). Resultados: No se encontraron mutaciones en el gen ERG11 y la sobre-expresión de éste sólo se presentó en 12,5% de las cepas resistentes (1/8). El mecanismo prevalente en la cepas resistentes fue la sobre-expresión de bombas de eflujo encontrándose en 62,5% de las cepas resistentes (5/8). Conclusión: El estudio de la expresión bombas de eflujo por q-PCR podría ser una herramienta diagnóstica útil para la detección temprana de resistencia a azoles en C. albicans.

Onychomycosis: clinical, mycological and in vitro susceptibility testing of isolates of Trichophyton rubrum

BACKGROUND: Onychomycosis or nail fungal infection is the most common nail disease. Despite the wide range of studies on this condition, it remains difficult to establish the correct diagnosis and effective treatment. OBJECTIVES: To evaluate the efficacy of classical laboratory methods for the diagnosis of onychomycosis, and the in vitro susceptibility of the its main etiological agent to antifungals used in routine. METHODS: Nail samples of 100 patients with clinically suspected feet onychomycosis were collected to confirm the diagnosis by direct mycological examination and fungal culture. In vitro antifungal susceptibility testing was performed against strains of the main dermatophyte isolated by microdilution, according to the standardized protocol (M38-A2 - CLSI) RESULTS: Clinical diagnosis of onychomycosis was confirmed by laboratory analysis in 59% of patients. Of these, 54.2% were positive only in direct mycological examination, 44.1% in direct mycological examination and culture, and one case (1.7%) was positive only in culture, resulting in weak agreement between these tests (Kappa = 0.385; p <0.001) High minimum inhibitory concentration values of fluconazole and itraconazole were observed in 66.7% and 25.0% of isolates of T. rubrum tested. Additionally, high MIC values of terbinafine and ciclopirox was detected in only one isolate, and this was one of the strains in which in vitro activity of itraconazole and fluconazole has not been proven. CONCLUSIONS: Poor agreement was observed between direct mycological examination and culture for the diagnosis of onychomycosis, with direct mycological examination being significantly more sensitive. Except for fluconazole, the other three antifungals tested showed good in vitro activity against clinical isolates of T. rubrum. .