Isolamento de leveduras patogênicas da microbiota superficial de tamanduás mantidos em cativeiro

A composição da microbiota fúngica do pelame de animais silvestres ainda é pouco conhecida. Estabelecer parâmetros microbiológicos que permitam prever eventos infecciosos oportunistas nesses animais pode ser útil na preservação de espécies amaçadas de extinção. O objetivo dessa investigação foi isolar e identificar leveduras de potencial patogênico do pelame de tamanduás mantidos em cativeiro. Vinte e sete tamanduás, provenientes da Fundação Parque Zoológico de São Paulo (FPZSP) e Parque Municipal Quinzinho de Barros (Zôo-Sorocaba, SP) foram pesquisados. Catorze espécimes serão de tamanduá-bandeira (Mymercophaga tridactyla) e 13 de tamanduá-mirim (Tamandua tetradactyla), dos quais, 63% machos e 37%, fêmeas. A técnica do quadrado do carpete foi empregada na obtenção das amostras de pelame. As leveduras isoladas foram identificadas por meio de suas características morfológicas e por método semi-automatizado ID-32CÒ. Para descrever as variáveis obtidas por meio do instrumento de pesquisa, foram verificadas a frequência de ocorrência e os resultados foram expressos em valores relativos. Foram isoladas, no total, 33 leveduras a partir das amostras de pelame dos 27 tamanduás. As espécies de leveduras isoladas foram: oito Candida guilliermondii (24,2%), três C. famata (9,1%), três C. kefyr (9,1%), duas C. glabrata (6,1%), três Cryptococcus laurentii (9,1%), um C. humicola (3,0%), seis Geotrichum candidum (18,2%), três Malassezia pachydermatis (9.1%), duas Rhodotorula glutinis (6,1%) e dois Trichosporon asahii (6,1%). Pode-se concluir que leveduras reconhecidamente patogênicas podem colonizar a microbiota do tegumento de tamanduás-bandeira e tamanduás-mirim mantidos em cativeiro e representam potencial risco de infecção oportunista para esses animais.

Diversity of endophytic bacteria and microfungi in Syzygium cumini fruit from West Java, Indonesia

Rossiana N, Fathurrohim MF, Indrawati I. 2021. Diversity of endophytic bacteria and microfungi in Syzygium cumini fruit from West Java, Indonesia. Biodiversitas 22: 3943-3948. Syzygium cumini L. Skells is a native evergreen tropical tree in Southeast Asia belong to the Myrtaceae family, known as the Java plum, jambul, jambolan, jamblang, or jamun. The bacterial and fungal endophytes associated with fruit have not been determined and functionally characterized. The endophytic microbes live inside the surface-sterilized fruits and have no visibly harmful effects on the plants. The purposes of the study were to isolate, characterize, and determine the diversity of endophytic bacteria and fungi in S. cumini fruit. The endophytes from S. cumini fruit were observed morphologically for identification. The result of isolation and identification showed there are four bacterial isolate endophytes (B. cereus, B. subtilis, B. megaterium, and Bacillus sp.) and four fungal endophytes (Candida guilliermondii, Penicillium sp., Mycelia sterilia, and Aspergillus sp.) isolated from S. cumini fruit. Keywords:Biodiversity, Bacterial endophyte, Fungi endophyte, Jamblang

Nucleus-Independent Chemical Shift (NICS) as a Criterion for the Design of New Antifungal Benzofuranones

The assertion made by Wu et al. that aromaticity may have considerable implications for molecular design motivated us to use nucleus-independent chemical shifts (NICS) as an aromaticity criterion to evaluate the antifungal activity of two series of indol-4-ones. A linear regression analysis of NICS and antifungal activity showed that both tested variables were significantly related (p < 0.05); when aromaticity increased, the antifungal activity decreased for series I and increased for series II. To verify the validity of the obtained equations, a new set of 44 benzofuran-4-ones was designed by replacing the nitrogen atom of the five-membered ring with oxygen in indol-4-ones. The NICS(0) and NICS(1) of benzofuran-4-ones were calculated and used to predict their biological activities using the previous equations. A set of 10 benzofuran-4-ones was synthesized and tested in eight human pathogenic fungi, showing the validity of the equations. The minimum inhibitory concentration (MIC) in yeasts was 31.25 µg·mL–1 for Candida glabrata, Candida krusei and Candida guilliermondii with compounds 15-32, 15-15 and 15-1. The MIC for filamentous fungi was 1.95 µg·mL–1 for Aspergillus niger for compounds 15-1, 15-33 and 15-34. The results obtained support the use of NICS in the molecular design of compounds with antifungal activity.

Identification of yeasts in different rubber leaf (Hevea brasiliensis) clones and their effects on the physical properties of fermented glutinous rice tapai

Tapai is one of the most popular traditional desserts in Malaysia and other Asian countries. Traditionally, tapai is wrapped in a rubber leaf to enhance the smell and increase its palatability. The study focused on identifying the yeasts present before and after the production of glutinous rice tapai wrapped in different rubber leaves clones, namely RRIM 2025, RRIM 2002, PB 260 and PB 350. The identification of the yeast was carried out using API 20C AUX test strips for all rubber leaves clones, glutinous rice tapai wrapped in RRIM 2025, RRIM 2002, PB 260, PB 350 and in a container (control). The results showed that Crytococcus laurentii, Rhodotorula mucilaginosa 2, Candida famata, Rhodotorula minuta were present in rubber leaf clones. While the yeasts that had been identified in tapai wrapped in rubber leaf were Candida guilliermondii, Rhodotorula mucilaginosa 2, Candida parapsilosis and Trichosporon mucoides and only C. guilliermondii was found in the container. The physical properties of the tapai that are wrapped in rubber leaves have a difference in texture, pH value and total soluble solids content compared to the control sample. The tapai sample wrapped in RRIM 2025 and RRIM 2002 had a high total soluble solid content of 45.8±0.14% and 45.78±0.16% °Bx, respectively. Meanwhile, the control sample has the highest pH value and the hardest rice kernels, which were 4.71±0.05 and 218.19±25.39 N, respectively. The results showed that the different yeasts present in the rubber leaf may cause changes in the physical properties of glutinous rice tapai.

Orbital apex syndrome with frontal abscess secondary to sinusitis due to Candida guilliermondii

Candida guilliermondii is an opportunistic pathogen that rarely causes invasive candidiasis even in immunocompromised humans. We report a case presentation of invasive C. guilliermondii rhinosinusitis causing an orbital and intracranial extension (frontal lobe abscess). An aggressive multidisciplinary team management is a key approach in invasive fungal sinusitis and avoided mortality in this case. When orbital apex syndrome secondary to sinusitis is encountered in an immunocompromised patient, the treating physician should consider fungal infection as a causative agent.

Morphological characteristics of Candida albicans, Candida krusei, Candida guilliermondii, and Candida glabrata biofilms, and response to farnesol

Background and Aim: Different Candida species isolated in humans and animals have different types of parasite activity. The most pathogenic species is Candida albicans followed by Candida tropicalis. However, the effects of the morphology of Candida krusei, Candida guilliermondii, and Candida glabrata biofilms on the pathogenicity of these species have not been fully characterized. To the best of our knowledge, there is no literature on the effect of farnesol on rare Candida species. This study aimed to check the effect of different farnesol concentrations on the species C. krusei, C. guilliermondii, and C. glabrata compared with the strain C. albicans ATCC 10231, which has been widely studied, and is a strong producer of biofilms. Materials and Methods: We studied the morphological and densitometric parameters of biofilms produced by Candida species under the influence of the drug farnesol (Sigma-Aldrich, St. Louis, MO). We used a heart brain broth with the addition of 2% bovine blood serum in 96-well plates. To each well, we added 100 μL of C. albicans, C. krusei, C. guilliermondii, or C. glabrata culture, and 0.2-400 μM farnesol. The microliter plates were cultured with the lid closed at 37°C for 48 h. Then, the liquid was removed, and the wells were washed 3 times with 200 μL phosphate buffer solution (pH 7.3). Biofilm fixation was performed using 150 μL of 96% ethanol for 15 min. Then, the microliter plates were dried for 20 min at 37°C, a 0.5% solution of crystalline violet was added, and the plates were placed in an incubator at 37°C. After 5 min, the contents of the wells were removed, washed 3 times with 200 μL of phosphate buffer solution (pH 7.2), and dried. The dye was extracted by washing with 200 μL of 96% ethanol for 30 min. The results were obtained using a photometric analyzer of enzyme immunoassay reactions at an optical density (OD) wavelength of 450 nm. Results: All of Candida spp. strains tested were susceptible to farnesol at concentrations ranging from 0.8 to 400 μM for C. albicans, C. krusei, and C. guilliermondii, and 12.5 to 400 μM for C. glabrata. Conclusion: This study provides new insights into the use of farnesol against biofilms produced by Candida species, but further studies in vivo are necessary to evaluate the effectiveness of the reduction of OD. To the best of our knowledge, the antimicrobial activity of farnesol against C. krusei, C. guilliermondii, and C. glabrata has not been reported previously, although studies have confirmed the inhibitory effect of farnesol on the growth of different microorganisms.

Short-Term Adaptation Strategy Improved Xylitol Production by Candida Guilliermondii on Sugarcane Bagasse Hemicellulosic Hydrolysate

One of the major bottlenecks of the biotechnological production of xylitol by pentose-fermenting yeasts is the presence of toxic compounds in the hemicellulosic hydrolysates, which inhibit the bioconversion of xylose into xylitol. In this work, short-term adaptation was evaluated as a strategy to minimize the toxicity of the sugarcane bagasse hemicellulosic hydrolysate to Candida guilliermondii FTI 20037. Yeast adaptation improved xylose assimilation as well as xylitol production. The beneficial effects of adaptation were more pronounced in the hydrolysate with higher concentration of toxic compounds, leading to an increase of 62.5% in the xylitol volumetric productivity in comparison to the use of non-adapted cells. In this condition, it was also verified the reduction of glycerol production (about 102%), a by-product formed as consequence of cellular stress, indicating a greater tolerance of adapted cells to the toxicity of hydrolysates. Short-term adaptation proved to be a promising strategy to improve considerably the microbial tolerance and overcome the toxicity of hydrolysates.

Composición y actividad antifúngica del aceite esencial de Fabiana imbricata contra levaduras del género Candida

El objetivo de este estudio fue evaluar la actividad anti-fungica del aceite esencial (AE) de Fabiana imbricata Ruiz & Pav contra cinco especies de Candida comúnmente asociadas a enfermedades ginecológicas. El aceite esencial de las hojas fresca de F. imbricata fue obtenido por hidrodestilación y caracterizado mediante la técnica de cromatografía de gases acoplada a espectrometría de masas (CG/EM). Se evaluó la actividad anti-fúngica a diferentes concentraciones del AE mediante el método de microdilución. Los compuestos más abundantes identificados en el AE (7a-isopropenil-4,5-dimetiloctahidroinden-4-il) metanol (43,66%), bulnesol (17,02%) y T-muurolol (5,75%). El AE mostro una potente y selectiva actividad anti-fúngica sobre el crecimiento de la levadura patógena Candida guilliermondii con una concentración mínima inhibitoria de 10 μg/mL, superior al control positivo clotrimazol que presento un valor de 15 μg/mL. Estos resultados confirman las propiedades antimicrobianas de los aceites esenciales y su posible uso en el manejo de las cepas de C. guilliermondii de importancia para pacientes inmune deprimidos y como posibles alternativas a los fungicidas sintéticos.