Expressão e caracterização da glicoproteína D do herpesvírus equídeo 1 em Pichia pastoris / Expression and characterization of equid herpesvirus 1 glycoprotein D in Pichia pastoris

O herpesvírus equídeo 1 (EHV-1) apresenta distribuição mundial e causa graves prejuízos à equideocultura. É agente de surtos de doença respiratória, reprodutiva e neurológica, em equídeos jovens e adultos. A glicoproteína D (gD) do envelope viral é essencial para ligação e penetração em células permissivas e direcionamento do sistema imunológico do hospedeiro, induz respostas imunes humorais e celulares, sendo um antígeno apropriado para ser utilizado em vacinas e imunodiagnóstico. O objetivo deste trabalho foi expressar e caracterizar a gD do EHV-1 em Pichia pastoris para posterior utilização como antígeno em técnicas de imunodiagnóstico e formulação de vacinas recombinantes. Uma sequência de DNA que codifica uma forma truncada da gDEHV-1 foi clonada no vetor pPICZαA de expressão em P. pastoris. Obteve-se uma proteína de ~41 kDa, como esperado. A proteína apresentou glicosilação entre 4 kDa e 16 kDa, demonstrada por deglicosilação enzimática. A proteína recombinante foi caracterizada antigenicamente e imunogenicamente por Western blot, utilizando-se anticorpos policlonais equinos anti-EHV-1, e por ELISA indireto em modelo murino, demonstrando que a gD recombinante manteve epítopos similares aos da proteína nativa. Esses resultados sugerem que a gDEHV-1 é um antígeno promissor para uso como imunobiológico no controle do EHV-1.(AU)

Equine herpesvirus 1 (EHV-1) has a worldwide distribution and causes serious damage to horse breeding. It is an agent of respiratory, reproductive and neurological disease outbreaks in young and adult equids. Viral envelope glycoprotein D (gD) is essential for binding and penetration into permissive cells and targeting the host immune system, inducing humoral and cellular immune responses, and is an appropriate antigen for use in vaccines and immunodiagnostics. The objective of this work was to express in Pichia pastoris and to characterize EHV-1 gD for later use as an antigen in immunodiagnostic techniques and formulation of recombinant vaccines. A DNA sequence encoding a truncated form of gDEHV-1 has been cloned into the P. pastoris expression vector pPICZαA. A protein of ~41 kDa was obtained as expected. The protein presented glycosylation between 4 kDa and 16 kDa, demonstrated by enzymatic deglycosylation. The recombinant protein was antigenically and immunogenically characterized by Western blot using equine polyclonal anti-EHV-1 antibodies, and by indirect ELISA in a murine model, demonstrating that the recombinant gD maintained epitopes similar to those of the native protein. These results suggest that gDEHV-1 is a promising antigen for use as an immunobiological in the control of EHV-1.(AU)

Expressão da L-asparaginase II de Saccharomyces cerevisiae recombinante extracelular com glicosilação humanizada em Pichia pastoris / Extracellular expression of Saccharomyces cerevisiae's L-asparaginase II in Pichia pastoris with humanized glycosylation

L-asparaginase é um inibidor eficiente do crescimento tumoral, usado em sessões de quimioterapia contra a Leucemia Linfoblástica Aguda (LLA), resultando na remissão completa da doença em 90% dos pacientes tratados. A L-asparaginase II de Saccharomyces cerevisiae (ScASNaseII) tem alto potencial de superar os efeitos adversos da L-asparaginase de bactéria, porém sua produção endógena resulta em uma proteína hipermanosilada e, consequentemente, imunogênica. A cepa de Pichia pastoris Glycoswitch tem a maquinaria para expressar e secretar altas quantidades de enzima com glicosilação humanizada. Nesse trabalho, descrevemos o processo genético para expressar a ScASNaseII no meio extracelular pela P. pastoris Glycoswitch, e também os parâmetros bioquímicos, perfil cinético, citotoxicidade contra células leucêmicas e a interferência da glicosilação na atividade da enzima obtida. Nossos dados mostram que a cepa aplicada foi capaz de expressar ScASNaseII no meio extracelular passível de purificação de proteínas contaminantes com apenas um passo cromatográfico. A atividade específica para asparagina foi 218,2 UI/mg e a atividade glutaminásica representou 3,1% da atividade asparaginásica. Os parâmetros cinéticos foram KM = 120,5 µM e a eficiência catalítica de 3,8 x 105 M-1s-1. Análises por meio de gel nativo sugerem uma conformação tetramérica de aproximadamente 150 kDa. Essa é uma nova estratégia de produzir essa enzima de forma extracelular, com mais facilidade de purificação e com melhores propriedades biotecnológicas

L-asparaginase is an efficient inhibitor of tumor development, used in chemotherapy sessions against acute lymphoblastic leukemia (ALL) tumor cell; its use results in 90% complete remission of the disease in treated patients. Saccharomyces cerevisiae's L-asparaginase II (ScASNaseII) has a high potential to overcome the side effects of bacteria L-asparaginase, but the endogenous production of it results in hypermannosylated immunogenic enzyme. However, Pichia pastoris Glycoswitch strain has the machinery to express and secrete high quantity of the enzyme and with humanized glycosylation. Here we describe the genetic process to acquire the ScASNaseII in the extracellular medium expressed by P. pastoris Glycoswitch, and the biochemical properties of the resultant enzyme, kinetic profile, cytotoxicity against ALL cell line and the interference of glycosylation in its activity. Our data show that the strain employed is able to express extracellular asparaginase active and possible to be purified of contaminant proteins using a single chromatographic step. The specific activity using asparagine was 218.2 IU.mg-1 and the glutaminase activity represents 3.1% of its asparaginase activity. The kinetics parameters were KM=120.5 µM and a catalytic efficiency of 3.8x105 M-1s-1. The Native-PAGE suggested a tetrameric protein conformation, with approximately 150 kDa. This is a novel strategy to produce this enzyme extracellularly, easier to purify and with better biotechnological properties

Bioconversion of hemicellulosic materials into ethanol by yeast, Pichia kudriavzevii 2-KLP1, isolated from industrial waste / Bioconversión de materiales hemicelulósicos en etanol por la levadura Pichia kudriavzevii 2-KLP1 aislada de residuos industriales

In the present work, a yeast strain Pichia kudriavzevii was identified on the basis of 18S rDNA, showing maximum growth at 30°C and pH 7.0. Among all the complex polysaccharides used, wheat bran proved to be the best substrate as indicated by the maximum growth of the yeast strain. The yeast isolate was capable of producing xylanase both intra-and extra-cellularly, the dominant form being extracellular. The maximum enzyme activity was determined at pH 5.0 and at 50°C. Na+, Mg2+ and Fe2+ presence caused a substantial increase in enzyme activity while a slight decrease (4.5%) was observed in the presence of Mn2+, Zn2+ and Cu2+. Pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) activities were assayed to confirm the presence of the ethanol pathway and PDC activity was much more pronounced (73%) compared to ADH activity (51%). The yeast strain can be employed to utilize hemicellulose containing agroindustrial residues for ethanol production.

En el presente estudio se identificó en aguas residuales de una zona industrial de Pakistán una cepa de la levadura Pichia kudriavzevii sobre la base del 18S ADNr, dicha cepa mostró un crecimiento máximo a 30 °C y a pH 7. Entre todos los sustratos de crecimiento evaluados para esta cepa, que incluyeron residuos industriales y medios definidos, el salvado de trigo demostró ser el mejor en función del crecimiento máximo alcanzado. Este aislado de levadura fue capaz de producir xilanasa intracelular y extracelular, esta última fue la forma predominante. Dicha capacidad enzimàtica mostró ser óptima a un pH de 5 y a 50°C. La presencia de Na+, Mg2+ y Fe2+ causó un incremento sustancial de la actividad enzimática, y hubo un ligero descenso (4,5%) en presencia de Mn2+, Zn2+ y Cu2+. Se evaluaron también las actividades de piruvato descarboxilasa y alcohol deshidrogenasa para confirmar la presencia de la vía del etanol. La actividad de la piruvato descarboxilasa fue mucho más pronunciada (73%) en comparación con la de alcohol deshidrogenasa (51%). Esta cepa de levadura puede emplearse para aprovechar los materiales hemicelulósicos de los residuos agroindustriales en la producción de etanol.

The potential of the newly isolated thermotolerant yeast Pichia kudriavzevii RZ8-1 for high-temperature ethanol production

Abstract High potential, thermotolerant, ethanol-producing yeasts were successfully isolated in this study. Based on molecular identification and phylogenetic analysis, the isolated thermotolerant yeasts were clustered in the genera of Pichia kudriavzevii, Candida tropicalis, Candida orthopsilosis, Candida glabrata and Kodamea ohmeri. A comparative study of ethanol production using 160 g/L glucose as a substrate revealed several yeast strains that could produce high ethanol concentrations at high temperatures. When sugarcane bagasse (SCB) hydrolysate containing 85 g/L glucose was used as a substrate, the yeast strain designated P. kudriavzevii RZ8-1 exhibited the highest ethanol concentrations of 35.51 g/L and 33.84 g/L at 37 °C and 40 °C, respectively. It also exhibited multi-stress tolerance, such as heat, ethanol and acetic acid tolerance. During ethanol fermentation at high temperature (42 °C), genes encoding heat shock proteins (ssq1 and hsp90), alcohol dehydrogenases (adh1, adh2, adh3 and adh4) and glyceraldehyde-3-phosphate dehydrogenase (tdh2) were up-regulated, suggesting that these genes might play a crucial role in the thermotolerance ability of P. kudriavzevii RZ8-1 under heat stress. These findings suggest that the growth and ethanol fermentation activities of this organism under heat stress were restricted to the expression of genes involved not only in heat shock response but also in the ethanol production pathway.

High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion

Abstract The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS) countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR) and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45 °C and 13% (v/v), respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40 °C and 43 °C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37 °C with an ethanol concentration of 72.69 g/L, a productivity of 1.59 g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ) at 40 °C were achieved using the Box-Behnken experimental design (BBD). The maximal ethanol concentration obtained during fermentation was 89.32 g/L, with a productivity of 2.48 g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.

Clinical significance of the isolation of Candida species from hospitalized patients

In this study, we isolated and phenotypically identified 108 yeast strains from various clinical specimens collected from 100 hospitalized patients at three tertiary hospitals in São Luís-Maranhão, Brazil, from July to December 2010. The isolates were analyzed for their susceptibility to four of the most widely used antifungal agents in the surveyed hospitals, amphotericin B, fluconazole, 5-flucytosine and voriconazole. The species identified were Candida albicans (41.4%), Candida tropicalis (30.1%), C. glabrata (7.4%), Candida parapsilosis (5.5%), Candida krusei (4.6%), Cryptococcus neoformans (4.6%), Trichosporon spp. (3.7%), Candida norvegensis (0.9%), Rhodotorula glutinis (0.9%) and Pichia farinosa (0.9%). A higher isolation rate was observed in the following clinical specimens: urine (54 isolates; 50%), respiratory tract samples (21 isolates; 19.4%) and blood (20 isolates; 18.6%). Candida albicans isolates were 100% sensitive to all antifungal agents tested, whereas Candida krusei and Crytococcus neoformans displayed intermediate resistance to 5-flucytosine, with Minimal Inhibitory Concentration (MIC) values of 8 mg/mL and 16 mg/mL, respectively. Both strains were also S-DD to fluconazole with an MIC of 16 mg/mL. C. tropicalis was resistant to 5-flucytosine with an MIC of 32 μg/mL. This study demonstrates the importance of identifying the yeast species involved in community and nosocomial infections.

Influence of physical and chemical factors on the survival of Pichia isolated from Glucose syrup / Influencia de factores fósicos y químicos sobre la sobrevivencia de Pichia aislada de jarabe de glucosa

Yeasts belonging to the genus Pichia were isolated from glucose syrup samples. Yeasts were identified as P. anomala ( it is now Wickerhamomyces anomala) and P. guilliermondii. These strains did not metabolize the nutritive preservatives, potassium sorbate or sodium benzoate when these were used as the single carbon source. P. anomala grew in culture media containing up to 1200 mg/L of both preservatives. Critical temperature and time of exposure for its inactivation were 60 °C and 3 min, respectively. P. guilliermondii grew in media containing up to 1400 mg/L of both preservatives. Critical temperature and time for inactivation of this Pichia were 80 °C and 2 min. This strain was able to grow in a wide range of temperatures (5 to 30 °C), pH (2.5 to 5.5) and glucose concentrations (200 to 800 g/L). At 5 °C and 800 g/L glucose (osmotic pressure, 0.110 atm), P.guilliermndii grew poorly, with no cell death because of its ability to sporulate. We determined that P. guilliermondii is a potentially contaminating yeast able to develop in a variety of foods, especially those with low pH or with high sugar concentrations (glucose above 400g/L) such as refreshments, juices, syrups and confected fruits and it is resistant to both food preservatives and low temperatures (5°C).

De muestras de jarabe de glucosa fueron aisladas levaduras que pertenecen al género Pichia. Estas fueron identificadas como P.anomala (actualmente Wickerhamomyces anomala) y P. guilliermondii, ambas cepas no metabolizan los conservantes alimenticios, sorbato de potasio o benzoato de sodio, al ser usados como única fuente de carbono. P. anomala desarrolló en medios de cultivo que contenían hasta 1200 mg/L de ambos conservantes. La temperatura y el tiempo crítico de exposición para su inactivación fueron 60 °C y 3 min, respectivamente. P.guilliermondii desarrolló en medios que contienen hasta 1400 mg/l de ambos conservantes. La tº y el tiempo crítico de inactivación fueron 80 °C y 2 min. Esta cepa fue capaz de desarrollar en un amplio rango de temperaturas (5 a 30 °C), pH (2,5 a 5,5) y concentraciones de glucosa (200 a 800 g/L). A 5 °C y glucosa 800 g/L (presión osmótica, 0,110 atm), P. guilliermondii desarrolló pobremente sin que se produzca la muerte celular debido a su capacidad de esporular. Se determinó que P. guilliermondii, es una levadura potencialmente contaminante que puede desarrollarse en una variedad de alimentos, especialmente aquellos con bajo pH o altas concentraciones de azúcar (glucosa, > 400 g/L) como en gaseosas, jugos, jarabes y frutas confitadas, y es resistente a ambos conservantes y bajas tº (5°C).

Spoilage yeasts in Patagonian winemaking: molecular and physiological features of Pichia guilliermondii indigenous isolates / Levaduras contaminantes en vinos patagónicos: características moleculares y fisiológicas de los aislamientos indígenas de Picchia guilliermondii

Yeasts belonging to the genus Dekkera/Brettanomyces, especially the species Dekkera bruxellensis, have long been associated with the production of volatile phenols responsible for off-flavour in wines. According to recent reports, the species Pichia guilliermondii could also produce these compounds at the initial stages of fermentation. Based on the abundance of P. guilliermondii in Patagonian winemaking, we decided to study the relevance of indigenous isolates belonging to this species as wine spoilage yeast. Twenty-three indigenous isolates obtained from grape surfaces and red wine musts were analyzed in their capacity to produce volatile phenols on grape must. The relationship between molecular Random Amplified Polymorphic DNA (RAPD) and physiological (killer biotype) patterns detected in indigenous populations of P. guilliermondii and volatile phenol production was also evaluated. Different production levels of 4-ethylphenol, 4-vinylguaiacol and 4-ethylguaiacol were detected among the isolates; however, the values were always lower than those produced by the D. bruxellensis reference strain in the same conditions. High levels of 4-vinylphenol were detected among P. guilliermondii indigenous isolates. The combined use of RAPD and killer biotype allowed us to identify the isolates producing the highest volatile phenol levels.

Las levaduras del género Dekkera/Brettanomyces, sobre todo la especie Dekkera bruxellensis, siempre han sido asociadas con la producción de fenoles volátiles responsables de aromas desagradables en los vinos. Recientemente, se ha demostrado que la especie Pichia guilliermondii también es capaz de producir estos compuestos, particularmente durante las etapas iniciales de la fermentación. Dada la abundancia de P. guilliermondii en las bodegas de la Patagonia, se decidió evaluar la importancia de algunos aislamientos indígenas de esta especie como levaduras alterantes de vinos regionales. Se evaluó la capacidad de producir fenoles volátiles en ensayos sobre mosto de 23 aislamientos de P. guilliermondii provenientes de superficie de uvas y de mostos de fermentación de vinos tintos. Asimismo, se analizó la relación entre los patrones moleculares (RAPD) y fisiológicos (biotipo killer) de estos aislamientos y la producción de fenoles volátiles. Se detectaron diferentes niveles de producción de 4-etilfenol, 4-vinilguayacol y 4-etilguayacol entre los aislamientos de P. guilliermondii analizados; sin embargo, los valores obtenidos fueron en todos los casos inferiores a los producidos por D. bruxellensis cepa de referencia en las mismas condiciones. En general, se detectaron altos niveles de 4-vinilfenol en los mostos fermentados con los aislamientos indígenas de P. guilliermondii. El uso combinado de RAPD-PCR y el biotipo killer permitió identificar los aislamientos que producen los niveles más altos de fenoles volátiles.

Kodamaea ohmeri infection in a neonate.

Kodamaea ohmeri is an extremely uncommon human pathogenic yeast. It causes opportunistic infection in immunocompromised hosts. We report a case of Kodamaea ohmeri fungemia in a preterm neonate who succumbed despite antifungal therapy.

Bases moleculares do efeito do pH na atividade catalítica de duas lisozimas digestivas de Musca domestica (Diptera) / Molecular basis of the pH effect on the catalytic activity of two digestive lysozymes from Musca dosmetica (Diptera)

Lisozimas são enzimas que fazem parte do mecanismo de defesa contra bactérias, no entanto lisozimas com função digestiva também são encontradas no trato digestivo de vertebrados e no intestino médio de insetos. As Iisozimas digestivas de insetos são do tipo "c" e assim compartilham semelhanças estruturais e mecanísticas com a lisozima da clara de ovo de galinha (HEWL). Entretanto, para desempenhar sua função digestiva, as lisozimas de insetos apresentam algumas propriedades particulares entre as quais se destaca um pH ótimo mais ácido em relação às lisozimas não-digestivas. Para elucidar as bases moleculares dessa diferença no pH ótimo, duas lisozimas digestivas (lisozima 1 — AAQ20048 e lisozima 2 — AAQ20047) da larva de Musca domestica (mosca — Diptera Cyclorrhapha), clonadas em Pichia pastoris e purificadas, foram caracterizadas estruturalmente e cineticamente com o substrato sintético (MUQ3) e natural (cápsulas de Micrococcus lysodeikticus). Foi observado que o efeito do pH na atividade das lisozimas 1 e 2 sobre o MUQ3 é uma curva com formato de sino e pH ótimo mais ácido que o da HEWL. Essas curvas foram reflexos da diminuição simultânea dos valores de p’K IND.a’s do nucleófilo e do doador de prótons...

First isolation of microorganisms from the gut diverticulum of Aedes aegypti (Diptera: Culicidae): new perspectives for an insect-bacteria association

We show for the first time that the ventral diverticulum of the mosquito gut (impermeable sugar storage organ) harbors microorganisms. The gut diverticulum from newly emerged and non-fed Aedes aegypti was dissected under aseptic conditions, homogenized and plated on BHI medium. Microbial isolates were identified by sequencing of 16S rDNA for bacteria and 28S rDNA for yeast. A direct DNA extraction from Ae. aegypti gut diverticulum was also performed. The bacterial isolates were: Bacillus sp., Bacillus subtilis and Serratia sp. The latter was the predominant bacteria found in our isolations. The yeast species identified was Pichia caribbica.

Fungemias por Pichia anomala en pacientes pediátricos inmunocomprometidos hospitalizados / Fungaemias by Pichia anomala in immunocompromised hospitalized pediatric patients

Pichia anomala es una levadura oportunista emergente, ocasionalmente responsable de graves infecciones hospitalarias en lactantes y niños inmunocomprometidos. En este trabajo describimos la presencia de P. anomala en sangre de 13 niños cateterizados en el Hospital del Niño Jesús de Tucumán (Argentina), en un periodo de 5 años. Estos representan el 9,71 por ciento de 350 muestras de sangre de pacientes pediátricos internados en unidades de terapia intermedia, cuidados intensivos y sala de oncología. P. anomala fue tan frecuente como Candida tropicalis en los hemocultivos examinados en el período en estudio. Teniendo en cuenta que la manipulación frecuente de catéteres y su uso prolongado favorecen el desarrollo de fungemia causadas por esta levadura, creemos imprescindible realizar mayores estudios epidemiológicos para determinar su real importancia clínica.

Pichia anomala is an opportunistic emerging yeast, occasionally responsible for serious hospitalinfections both in lactating babies and in immunocompromised children. We describe herein the presence of P. anomala in the blood of thirteen catherized children which was detected at the Hospital del Niño Jesús de Tucumán (Argentina), within a 5-year period. The above cases represent 9.71 percent out of the 350 blood samplescollected from pediatric patients admitted in intermediate therapy, intensive care and oncology wards.P. anomala was as frequent as Candida tropicalis in the blood cultures under examination during the period ofstudy.Considering that repeated catheter manipulation and prolonged use favour the development of fungaemiacaused by this yeast, we think it is most necessary to carry out further epidemiological studies to assess itsreal clinical significance.

Actividad in vitro de 5 antifúngicos contra aislados clínicos y ambientales de pichia anomala / In vitro activity of 5 antifungal against environmental and clinical isolates of pichia anomala

Las infecciones fúngicas han aumentado en el último tiempo, entre ellas, las infecciones por levaduras emergentes, cuyos patrones de sensibilidad no han sido estudiados debido a la inexistencia de patrones de temperatura y medios de cultivo apropiados para realizar test de sensibilidad. El presente trabajo, fue propuesto como un modelo experimental de Pichia anomala, aislada de pacientes con MICs superiores que los aislados ambientales, siendo la anfotericina B el antifúngico con la mejor actividad antifúngica.

Perfil de sensibilidade a drogas antifúngicas e tipagem molecular de isolados de Pichia anomala provenientes de pacientes com fungemia nosocomial / Susceptibility profile to antifungal drugs and molecular typing of Pichia anomala isolated from patients presenting nosocomial fungemia

Nos últimos anos, as infecções fúngicas têm se caracterizado pelo seu aumento em freqüência e gravidade das infecções, bem como pela diversidade dos fungos isolados. Candida spp representa o quarto grupo de patógenos nosocomiais mais comumente isolados no sangue, porém fungemias causadas por Pichia anomala têm sido descritas com relativa freqüência. No presente estudo, 42 isolados de P. anomala de hemocultura foram analisados. /In the last years, fungal infections have been characterized by increased frequency and gravity of the infections, as well as for the diversity of isolated fungi. Candida spp represents the fourth group of nosocomial pathogens more frequently isolated in peripheral blood. However, fungemias caused by Pichia anomala have been described with relative frequency. In the present study, 42 blood isolates of P. anomala were analyzed. Approximately 100 per cent of them showed susceptibility to fluconazole, voriconazole and amphotericin B, In respect to itraconazole, 32 per cent of the isolates were susceptible, 66 per cent, susceptible-dose dependent and 2 per cent, resistant to this antifungal drug. Electrophoretic karyotyping evidenced different types and subtypes among non- related isolates. Identical karyotype patterns were determined among sequential samples from the same patient and samples from an outbreak. This work presents the greatest number of P. anomala isolates already analyzed in respect to the yeast susceptibility to antifungal agents as well as it demonstrates that electrophoretic karyotyping ...

Fungemias por hansenula anómala en el Hospital Privado Centro Médico de Caracas / Fungemia by hansenula anomala in the Hospital Privado Centro Médico of Caracas

Se revisaron en forma retrospectiva las histórias clínicas de todos los pacientes en los cuales se aisló Hansenula anómala en los hemocultivos realizados en el Laboratorio de Microbiología del Hospital Privado Centro Médico de Caracas, en el lapso de 2 años y medio, comprendido entre agosto 1994 y febrero 1997. De 57 pacientes se obtuvo 64 hemocultivos positivos, aislándose 64 especies de Candida. Hansenula anómala se obtuvo en 15 hemocultivos de 15 pacientes diferentes, representando un 26,3 por ciento del total de pacientes, un 23,4 por ciento del total de las candidas y un 30,6 por ciento de las variedades no albicans. La Candida albicans se aisló en 15 pacientes (26,3 por ciento del total). De los pacientes que presentaron Hansenula anómala en sus hemocultivos, el 100 por ciento cumplieron con criterios clínicos de severidad. El rango de edad estaba comprendido entre 1 mes y 76 años, con una media de 43, de los cuales 6 eran masculinos y 9 femeninos. De este grupo de pacientes, 12 ingresaron con patología abdominal, siendo intervenidos quirúrgicamente 10 de estos. De los tres pacientes restantes, dos ameritaron cirugía no abdominal. Todos los pacientes recibieron antibióticos de amplio espectro, nutrición parenteral total y le fue colocado catéteres centrales. Nueve pacientes (60 por ciento) tuvieron criterios de sepsis. Los días de hospitalización oscilaron entre 7 y 101 días, con un promedio de 37. Doce pacientes ameritaron ingreso a la Unidad de Terapia Intensiva. Se inició Anfotericina B en 8 pacientes, con buena respuesta en el 100 por ciento. Seis pacientes recibieron como terapia inicial Fluconazol: 2 con respuesta satisfactoria; 1 fallecido no relacionado con la infección por Hansenula anómala y los tres restantes ameritaron cambio a Anfotericina B. Un paciente no recibió tratamiento antifúngico desconociéndose su evolución.

Levaduras aisladas de diversos tipos de alimentos / Yeast isolated from differents type of foods

Se investigó la presencia de levaduras en 4 grupos de alimentos constituídos por frutas frescas, frutas procesadas, derivados de leche y carnes industrializadas, aislándose 392 muestras de levaduras pertenecientes a 11 especies de Candida, 6 de Debaryomyces y 3 de Pichia. Los géneros Candida y Debaryomyces se detectaron en los 4 grupos de alimentos; Pichia no se detectó en carnes industrializadas