RESUMEN
RESUMEN El objetivo de la presente investigación fue evaluar la calidad higiénico-sanitaria de dos sistemas de ordeño en fincas bovinas del municipio Maturín estado Monagas (Venezuela). El ensayo tuvo una duración de seis semanas, se calculó la eficiencia higiénica (%EH) de las instalaciones, el personal, la rutina de ordeño, la limpieza-desinfección y el almacenamiento-transporte de dos unidades de producción. Adicionalmente, se determinó la población de bacterias aerobias mesófilas (BAM) que se cuantificaron en un experimento en bloques al azar, con arreglo factorial de los tratamientos (2x2) donde el factor A, correspondió al sistema de ordeño manual y mecánico y el factor B, a la aplicación y omisión de secado de los pezones de cada animal previo al ordeño. La variable se examinó por análisis de varianza y sus valores promedios comparados por Tukey al 5% de probabilidad. El %EH de las fincas evaluadas fue de 66,66% para la finca 2 y de 54,84% para la finca 1, considerados no satisfactorios. Los resultados obtenidos para la variable BAM indican que el factor sistema de ordeño mostró diferencia altamente significativa (p ≤ 0,01); el sistema manual presentó el menor conteo con 5,24 Log10 UFC/ mL; mientras que para el factor condición de secado se constató diferencia significativa (p ≤ 0,05), ya que la aplicación de secado presentó la menor población de bacterias aerobias mesófilas con 5,25 Log10 UFC/mL. Las medidas higiénicas y sanitarias implementadas en la rutina de ordeño influyeron directamente en la calidad de la leche cruda.
ABSTRACT The objective of the present investigation, was to evaluate the 'Hygienic-Sanitary Quality of two Milking Systems in Bovine Farms' in Vuelta Larga Sector, Maturín City, Monagas State (Venezuela). The trial lasted six weeks, in which the Hygienic Efficiency (% EH) of the facilities, the workers, the milking routine, the cleaning and disinfection measures and the storage and transport of both milking systems, were calculated. Furthermore, the population of Mesophilic Aerobic Bacteria (BAM) was determined ; The data were processed following a distribution in random blocks with factorial arrangement (2x2) whose factor A represented the milking system: manual and mechanical, and the factor B was the application and omission of manual drying of teats for each animal prior to milking. The percentage of Hygienic Efficiency (% EH) of the farms evaluated was not satisfactory, corresponding to 66.66% in the farm 2 and 54.84% in the farm 1. The variable was examined by analysis of variance and its mean values compared by Tukey test at 5% of probability. Factor A achieved a highly significant difference (p ≤0.01), with the manual system obtaining the lowest count with 5.24 Log10 CFU / mL. In factor B significant difference was found (p≤0.05), the drying application decreased the BAM population with 5.25 Log10 CFU / mL. The Hygienic and Sanitary measures implemented in the milking routine directly influence the quality of raw milk.
Asunto(s)
Animales , Bovinos , Bacterias Aerobias , Esterilización , Perfiles Sanitarios , Leche , Buenas Prácticas de Manipulación , Líquido Aspirado del Pezón , Microbiología , Bacterias , Bovinos , Diagnóstico , Eficiencia , PezonesRESUMEN
In 2018, the Mexican Caribbean coast received a massive influx of pelagic Sargassum spp. that accumulated and decayed on beaches producing organic decomposition products that made the water turbid and brown. Between May and September of the same year there were several reports of mass mortality of marine biota in this area. From these reports we estimate that organisms belonging to 78 faunal species died as result of this event, with demersal neritic fish and Crustacea being the most affected groups. The cause of mortality appears to be the combined effect of high ammonium and hydrogen sulfide concentrations, together with hypoxic conditions. If massive arrival of pelagic Sargassum spp. continues and algae is left to decay on the beach in large volumes then deterioration in water quality could affect coral reefs close to shore. Furthermore, barriers placed in lagoons to intercept the Sargassum spp. before it reaches the beach could impact reef fauna if the algae is left to die and sink on site.
Asunto(s)
Crustáceos , Peces , Sargassum/fisiología , Agua de Mar/química , Compuestos de Amonio/análisis , Animales , Organismos Acuáticos , Región del Caribe , Sulfuro de Hidrógeno/análisis , México , Mortalidad , Agua de Mar/análisis , Calidad del AguaRESUMEN
To assess the value of using whole blood samples for the molecular diagnosis of histoplasmosis, we applied an in-house DNA extraction method and a nested PCR targeting a 210 bp specific segment of the Histoplasma capsulatum HcP100 gene. A whole blood volume of 2.5-3 milliliters was centrifuged and the cellular pellet was treated with Trichoderma harzianum lyticase and proteinase K prior to applying a conventional phenol DNA extraction. This procedure allowed complete cell lysis, high DNA yield and specific amplification. The PCR detection limit was 0.25-1 yeast cells/ml of blood sample. The method was assessed on 31 blood samples from 19 patients with microbiological diagnosis of histoplasmosis, 30 healthy persons and 21 patients with other mycoses or mycobacterial diseases. Positive results were obtained in samples from 17/19 patients with histoplasmosis (14/15 immunocompromised and 3/4 without known immunological disorder). Blood samples from the 30 healthy controls and 20 patients with other conditions proved negative; the only false positive result was obtained from a patient with Mycobacterium avium-intracellulare infection. With 89% sensitivity and 98% specificity, this molecular method for detection of the agent in blood shows promising for the rapid diagnosis of human histoplasmosis.
Asunto(s)
Fungemia/diagnóstico , Histoplasmosis/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Adulto , Anciano , Argentina/epidemiología , Niño , Comorbilidad , ADN de Hongos/aislamiento & purificación , Enfermedades Endémicas , Reacciones Falso Positivas , Femenino , Fungemia/epidemiología , Infecciones por VIH/epidemiología , Histoplasma/genética , Histoplasma/aislamiento & purificación , Histoplasmosis/sangre , Histoplasmosis/epidemiología , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad , Infección por Mycobacterium avium-intracellulare/sangre , Infección por Mycobacterium avium-intracellulare/epidemiología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/microbiología , Estudios Retrospectivos , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Se evaluó el uso de sangre entera para el diagnóstico molecular de histoplasmosis utilizando un método artesanal de extracción de ADN fúngico y una PCR anidada que amplifica una porción del gen HcP100 específica de Histoplasma capsulatum. La sangre entera se trató con liticasa, enzima lisante de Trichoderma harzianum y proteinasa K, seguido de una extracción fenólica. Este tratamiento permitió una lisis completa de las células, mostró buen rendimiento en la obtención de ADN y posibilitó la detección de la banda de 210 pb específica de H. capsulatum en la PCR anidada. El límite de detección fue de 0,25-1 levaduras/ml de sangre. El método se evaluó en 31 muestras de sangre de 19 pacientes con diagnóstico microbiológico de histoplasmosis, en 21 muestras de pacientes con otras micosis o infecciones por micobacterias y en 30 controles sanos. La PCR fue positiva en sangre para 17/19 pacientes con histoplasmosis (14/15 inmunocomprometidos y 3/4 sin inmunocompromiso aparente). Las muestras de sangre de los 30 controles sanos y de 20 pacientes con otras patologías fueron negativas, sólo hubo un falso positivo correspondiente a un paciente con infección por Mycobacterium avium-intracellulare. El método presentó 89% de sensibilidad y 96% de especificidad para el diagnóstico de histoplasmosis en sangre entera.
To assess the value of using whole blood samples for the molecular diagnosis of histoplasmosis, we applied an in-house DNA extraction method and a nested PCR targeting a 210 bp specific segment of the Histoplasma capsulatum HcP100 gene. A whole blood volume of 2.5-3 milliliters was centrifuged and the cellular pellet was treated with Trichoderma harzianum lyticase and proteinase K prior to applying a conventional phenol DNA extraction. This procedure allowed complete cell lysis, high DNA yield and specific amplification. The PCR detection limit was 0.25-1 yeast cells/ml of blood sample. The method was assessed on 31 blood samples from 19 patients with microbiological diagnosis of histoplasmosis, 30 healthy persons and 21 patients with other mycoses or mycobacterial diseases. Positive results were obtained in samples from 17/19 patients with histoplasmosis (14/15 immunocompromised and 3/4 without known immunological disorder). Blood samples from the 30 healthy controls and 20 patients with other conditions proved negative; the only false positive result was obtained from a patient with Mycobacterium avium-intracellulare infection. With 89% sensitivity and 98% specificity, this molecular method for detection of the agent in blood shows promising for the rapid diagnosis of human histoplasmosis.
Asunto(s)
Adulto , Anciano , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Fungemia/diagnóstico , Histoplasmosis/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Argentina/epidemiología , Comorbilidad , ADN de Hongos/aislamiento & purificación , Enfermedades Endémicas , Reacciones Falso Positivas , Fungemia/epidemiología , Infecciones por VIH/epidemiología , Histoplasma/genética , Histoplasma/aislamiento & purificación , Histoplasmosis/sangre , Histoplasmosis/epidemiología , Huésped Inmunocomprometido , Infección por Mycobacterium avium-intracellulare/sangre , Infección por Mycobacterium avium-intracellulare/epidemiología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/microbiología , Estudios Retrospectivos , Sensibilidad y EspecificidadAsunto(s)
Coccidioidomicosis/diagnóstico , Animales , Coccidioidomicosis/microbiología , Perros , MasculinoAsunto(s)
Animales , Perros , Masculino , Coccidioidomicosis/diagnóstico , Coccidioidomicosis/microbiologíaRESUMEN
For the first time in Argentina, we describe a strain of Histoplasma capsulatum var. capsulatum with an aberrant morphology that was isolated from a single patient with AIDS. Mycelial phase cultures on agar Sabouraud at 25-28 degrees C showed white, glabrous, umbilicated and centrally radiated colonies. Unusual microscopic findings were the absence of typical conidia, the presence of terminal/intercalary chlamydoconidia with a diameter of 4 pm and of thickened hyphae. Fungal identification was confirmed by the detection of bands H and M species specific antigens in mycelial culture supernatants and reversion to the typical yeast phase on agar brain-heart-cysteine at 37 degrees C. The genomic DNA profile obtained by RAPD-PCR with primers 1281-1283 coincided with the predominant profile of H. capsulatum among isolates from Argentine patients.
Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Histoplasma/aislamiento & purificación , Histoplasmosis/microbiología , Argentina , ADN de Hongos/análisis , Histoplasma/citología , Humanos , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
We report the first isolation of Histoplasma capsulatum var. capsulatum from a male bat Eumops bonariensis captured in Buenos Aires city in 2003. The pathogen was recovered from spleen and liver specimens, and was identified by its phenotypic characteristics. PCR with primers 1283, (GTG)5, (GACA)4 and M13 was used to compare both bat isolates with 17 human isolates, 12 from patients residing in Buenos Aires city, and 5 from other countries of the Americas. The profiles obtained with the four primers showed that both bat isolates were identical to each other and closer to Buenos Aires patients than to the other isolates (similarity percentage: 91-100% and 55-97%, respectively). The high genetic relationship between bat isolates and those from patients living in Buenos Aires suggests a common source of infection. This is the first record of E. bonariensis infected with H. capsulatum in the world, and the first isolation of the fungus in the Argentinean Chiroptera population. In the same way as these wild mammals act as reservoir and spread the fungus in the natural environment, infection in urban bats could well be associated with the increase in histoplasmosis clinical cases among immunosuppressed hosts in Buenos Aires city.
Asunto(s)
Quirópteros/microbiología , Histoplasma/aislamiento & purificación , Américas , Animales , Argentina/epidemiología , Quirópteros/clasificación , ADN de Hongos/genética , Reservorios de Enfermedades , Histoplasma/genética , Histoplasmosis/epidemiología , Histoplasmosis/microbiología , Histoplasmosis/transmisión , Humanos , Huésped Inmunocomprometido , Hígado/microbiología , Masculino , Infecciones Oportunistas/epidemiología , Infecciones Oportunistas/microbiología , Infecciones Oportunistas/transmisión , Especificidad de la Especie , Bazo/microbiología , Salud UrbanaRESUMEN
Se comunica el primer aislamiento de Histoplasma capsulatum var. capsulatum de un murciélago macho de la especie Eumops bonariensis, capturado en la ciudad de Buenos Aires en 2003. Los aislamientos fueron recuperados de bazo e hígado e identificados fenotípicamente. Se los comparó por PCR, con 17 aislamientos clínicos, 12 de pacientes residentes en la ciudad de Buenos Aires y cinco de otros países de América, usando los iniciadores 1283, (GTG)5, (GACA)4 y M13. Con los cuatro iniciadores, los perfiles de los aislamientos de murciélago resultaron idénticos entre sí y más relacionados a los de pacientes de Buenos Aires que a los de otros países (porcentaje de similitud: 91-100% y 55-87%, respectivamente). La alta relación genética entre los aislamientos obtenidos del murciélago y de los humanos residentes en Buenos Aires sugiere una fuente común de infección. Este es el primer registro de E. bonariensis infectado con H. capsulatum en el mundo, y el primer aislamiento del hongo en la población de quirópteros de la Argentina. Así como estos mamíferos actúan como reservorio y dispersan el hongo en la naturaleza, la infección en murciélagos urbanos podría asociarse al elevado número de casos de histoplasmosis entre pacientes inmunodeprimidos en la ciudad de Buenos Aires.
We report the first isolation of Histoplasma capsulatum var. capsulatum from a male bat Eumops bonariensis captured in Buenos Aires city in 2003. The pathogen was recovered from spleen and liver specimens, and was identified by its phenotypic characteristics. PCR with primers 1283, (GTG)5, (GACA)4 and M13 was used to compare both bat isolates with 17 human isolates, 12 from patients residing in Buenos Aires city, and 5 from other countries of the Americas. The profiles obtained with the four primers showed that both bat isolates were identical to each other and closer to Buenos Aires patients than to the other isolates (similarity percentage: 91-100% and 55-97%, respectively). The high genetic relationship between bat isolates and those from patients living in Buenos Aires suggests a common source of infection. This is the first record of E. bonariensis infected with H. capsulatum in the world, and the first isolation of the fungus in the Argentinean Chiroptera population. In the same way as these wild mammals act as reservoir and spread the fungus in the natural environment, infection in urban bats could well be associated with the increase in histoplasmosis clinical cases among immunosuppressed hosts in Buenos Aires city.
Asunto(s)
Animales , Humanos , Masculino , Quirópteros/microbiología , Histoplasma/aislamiento & purificación , Américas , Argentina/epidemiología , Quirópteros/clasificación , Reservorios de Enfermedades , ADN de Hongos/genética , Histoplasma/genética , Histoplasmosis/epidemiología , Histoplasmosis/microbiología , Histoplasmosis/transmisión , Huésped Inmunocomprometido , Hígado/microbiología , Infecciones Oportunistas/epidemiología , Infecciones Oportunistas/microbiología , Infecciones Oportunistas/transmisión , Especificidad de la Especie , Bazo/microbiología , Salud UrbanaRESUMEN
We report the first isolation of Histoplasma capsulatum var. capsulatum from a male bat Eumops bonariensis captured in Buenos Aires city in 2003. The pathogen was recovered from spleen and liver specimens, and was identified by its phenotypic characteristics. PCR with primers 1283, (GTG)5, (GACA)4 and M13 was used to compare both bat isolates with 17 human isolates, 12 from patients residing in Buenos Aires city, and 5 from other countries of the Americas. The profiles obtained with the four primers showed that both bat isolates were identical to each other and closer to Buenos Aires patients than to the other isolates (similarity percentage: 91-100
and 55-97
, respectively). The high genetic relationship between bat isolates and those from patients living in Buenos Aires suggests a common source of infection. This is the first record of E. bonariensis infected with H. capsulatum in the world, and the first isolation of the fungus in the Argentinean Chiroptera population. In the same way as these wild mammals act as reservoir and spread the fungus in the natural environment, infection in urban bats could well be associated with the increase in histoplasmosis clinical cases among immunosuppressed hosts in Buenos Aires city.
RESUMEN
In order to contribute to the knowledge of the relative frequency of chronic fungal diseases and assess the performance of diagnostic laboratories in Argentina, a multicenter study was performed with the participation of 25 medical centers located in 12 different provinces and Buenos Aires City. Between 04-01-2000 and 03-30-2001, 965 serum specimens from patients clinically suspected of having histoplasmosis (HP), paracoccidioidomycosis (PCM), coccidioidomycosis (CM) or aspergilosis were analyzed. Agar immunodiffusion tests (IDD) were done locally. All positive and 35% of negative sera were retested in the reference center. Results of laboratories of origin showed 98.8% concordance with those of reference center. Antibodies against any of the etiological agents were detected in 120 specimens from 98 patients. Endemic mycoses (HP, PCM and CM) were diagnosed in 70 patients (71.4%) and aspergilosis in 28 (28.6%). The frequencies of the different mycoses in decreasing order were PCM 47 patients (47.9%), aspergilosis 28 patients (28.6%), HP 13 patients (13.3%) and CM 10 patients (10.2%). The study was carried out on a voluntary basis and some areas of the country were not represented. However, the frequencies were in range with the expected rates in the population under study.
Asunto(s)
Enfermedades Endémicas , Micosis/epidemiología , Argentina/epidemiología , Aspergilosis Broncopulmonar Alérgica/diagnóstico , Aspergilosis Broncopulmonar Alérgica/epidemiología , Coccidioidomicosis/diagnóstico , Coccidioidomicosis/epidemiología , Histoplasmosis/diagnóstico , Histoplasmosis/epidemiología , Humanos , Inmunodifusión , Micosis/diagnóstico , Paracoccidioidomicosis/diagnóstico , Paracoccidioidomicosis/epidemiología , Estudios SeroepidemiológicosRESUMEN
Se realizó entre 01-04-2000 y 30-03-2001, un estudio de corte transversal, para conocer la frecuencia relativa de las enfermedades por hongos dimorfos y Aspergillus spp. en la República Argentina y evaluar la certeza en el diagnóstico de los laboratorios de diferentes áreas geográficas. Participaron 25 centros de salud provenientes de 12 provincias y de la Ciudad Autónoma de Buenos Aires. Fueron analizados en el laboratorio de origen 965 sueros de pacientes con sospecha clínica de histoplasmosis (HP), paracoccidioidomicosis (PCM), coccidioidomicosis (CM) y aspergilosis. Todos los sueros positivos y el 35% de los negativos fueron reevaluados en el laboratorio de referencia por inmunodifusión doble en agar. La concordancia entre los resultados obtenidos en los centros de origen y el de referencia fue de 98,8%. Se detectaron anticuerpos específicos en 120 sueros correspondientes a 98 pacientes. El 71,4% (70 casos) de los diagnósticos correspondió a micosis endémicas (HP, PCM y CM) y el resto a aspergilosis. PCM fue diagnosticada en 47,9% (47 casos), aspergilosis en 28,6% (28 casos), HP en13,3% (13 casos) y CM en 10,2% (10 casos). La participación en este estudio fue voluntaria y no todos los centros del país estaban representados, sin embargo, las frecuencias de enfermedades fúngicas fueron las esperadas y coincidentes con estudios previos realizados a nivel nacional.
In order to contribute to the knowledge of the relative frequency of chronic fungal diseases and assess the performance of diagnostic laboratories in Argentina, a multicenter study was performed with the participation of 25 medical centers located in 12 different provinces and Buenos Aires City. Between 04-01-2000 and 03-30-2001, 965 serum specimens from patients clinically suspected of having histoplasmosis (HP), paracoccidioidomycosis (PCM), coccidioidomycosis (CM) or aspergilosis were analyzed. Agar immunodiffusion tests (IDD) were done locally. All positive and 35% of negative sera were retested in the reference center. Results of laboratories of origin showed 98.8% concordance with those of reference center. Antibodies against any of the etiological agents were detected in 120 specimens from 98 patients. Endemic mycoses (HP, PCM and CM) were diagnosed in 70 patients (71.4%) and aspergilosis in 28 (28.6%). The frequencies of the different mycoses in decreasing order were PCM 47 patients (47.9%), aspergilosis 28 patients (28.6%), HP 13 patients (13.3%) and CM 10 patients (10.2%). The study was carried out on a voluntary basis and some areas of the country were not represented. However, the frequencies were in range with the expected rates in the population under study.
Asunto(s)
Humanos , Enfermedades Endémicas , Micosis/epidemiología , Argentina/epidemiología , Aspergilosis Broncopulmonar Alérgica/diagnóstico , Aspergilosis Broncopulmonar Alérgica/epidemiología , Coccidioidomicosis/diagnóstico , Coccidioidomicosis/epidemiología , Histoplasmosis/diagnóstico , Histoplasmosis/epidemiología , Inmunodifusión , Micosis/diagnóstico , Paracoccidioidomicosis/diagnóstico , Paracoccidioidomicosis/epidemiología , Estudios SeroepidemiológicosRESUMEN
In order to contribute to the knowledge of the relative frequency of chronic fungal diseases and assess the performance of diagnostic laboratories in Argentina, a multicenter study was performed with the participation of 25 medical centers located in 12 different provinces and Buenos Aires City. Between 04-01-2000 and 03-30-2001, 965 serum specimens from patients clinically suspected of having histoplasmosis (HP), paracoccidioidomycosis (PCM), coccidioidomycosis (CM) or aspergilosis were analyzed. Agar immunodiffusion tests (IDD) were done locally. All positive and 35
of negative sera were retested in the reference center. Results of laboratories of origin showed 98.8
concordance with those of reference center. Antibodies against any of the etiological agents were detected in 120 specimens from 98 patients. Endemic mycoses (HP, PCM and CM) were diagnosed in 70 patients (71.4
) and aspergilosis in 28 (28.6
). The frequencies of the different mycoses in decreasing order were PCM 47 patients (47.9
), aspergilosis 28 patients (28.6
), HP 13 patients (13.3
) and CM 10 patients (10.2
). The study was carried out on a voluntary basis and some areas of the country were not represented. However, the frequencies were in range with the expected rates in the population under study.
RESUMEN
We analyzed the in vitro infection process by P. brasiliensis and the effect of extracellular factor(s) produced on monolayers of mammalian Vero cell lines. The yeast phase of four strains was studied: B339 (avirulent or slightly virulent), U, (intermediate virulence), 93745 and 63265 (both highly virulent). Strains of intermediate and high virulence had higher adherence at first contact (about 16%). Strain B339 had a slower adherence at first contact (8%) than the others during the same period. The production of extracellular proteases, soluble extracellular factor(s) and extracellular antigen gP43 showed no correlation with the in vitro physiopathogenicity of the analyzed strains. We demonstrate that the Vero model presented in this paper is a suitable system to study infection and virulence in vitro. We are currently assessing its usefulness as a tool for the analysis of the interaction between pathogen, host and antifungal agents.
Asunto(s)
Antígenos Fúngicos , Micología/métodos , Paracoccidioides/fisiología , Animales , Chlorocebus aethiops , Medios de Cultivo , Proteínas Fúngicas/biosíntesis , Glicoproteínas/biosíntesis , Oligosacáridos/biosíntesis , Paracoccidioides/clasificación , Paracoccidioides/crecimiento & desarrollo , Paracoccidioides/patogenicidad , Especificidad de la Especie , Células Vero/microbiología , VirulenciaRESUMEN
We analyzed the in vitro infection process by P. brasiliensis and the effect of extracellular factor(s) produced on monolayers of mammalian Vero cell lines. The yeast phase of four strains was studied: B339 (avirulent or slightly virulent), U, (intermediate virulence), 93745 and 63265 (both highly virulent). Strains of intermediate and high virulence had higher adherence at first contact (about 16). Strain B339 had a slower adherence at first contact (8) than the others during the same period. The production of extracellular proteases, soluble extracellular factor(s) and extracellular antigen gP43 showed no correlation with the in vitro physiopathogenicity of the analyzed strains. We demonstrate that the Vero model presented in this paper is a suitable system to study infection and virulence in vitro. We are currently assessing its usefulness as a tool for the analysis of the interaction between pathogen, host and antifungal agents.(AU)
Asunto(s)
Estudio Comparativo , Animales , Micología/métodos , Paracoccidioides/fisiología , Chlorocebus aethiops , Medios de Cultivo , Proteínas Fúngicas/biosíntesis , Glicoproteínas/biosíntesis , Oligosacáridos/biosíntesis , Paracoccidioides/clasificación , Paracoccidioides/crecimiento & desarrollo , Paracoccidioides/patogenicidad , Especificidad de la Especie , Células Vero/microbiología , VirulenciaRESUMEN
We analyzed the in vitro infection process by P. brasiliensis and the effect of extracellular factor(s) produced on monolayers of mammalian Vero cell lines. The yeast phase of four strains was studied: B339 (avirulent or slightly virulent), U, (intermediate virulence), 93745 and 63265 (both highly virulent). Strains of intermediate and high virulence had higher adherence at first contact (about 16). Strain B339 had a slower adherence at first contact (8) than the others during the same period. The production of extracellular proteases, soluble extracellular factor(s) and extracellular antigen gP43 showed no correlation with the in vitro physiopathogenicity of the analyzed strains. We demonstrate that the Vero model presented in this paper is a suitable system to study infection and virulence in vitro. We are currently assessing its usefulness as a tool for the analysis of the interaction between pathogen, host and antifungal agents.
Asunto(s)
Animales , Micología , Paracoccidioides , Células Vero/microbiología , Chlorocebus aethiops , Medios de Cultivo , Especificidad de la Especie , Glicoproteínas/biosíntesis , Oligosacáridos/biosíntesis , Paracoccidioides , Proteínas Fúngicas/biosíntesis , VirulenciaRESUMEN
We analyzed the in vitro infection process by P. brasiliensis and the effect of extracellular factor(s) produced on monolayers of mammalian Vero cell lines. The yeast phase of four strains was studied: B339 (avirulent or slightly virulent), U, (intermediate virulence), 93745 and 63265 (both highly virulent). Strains of intermediate and high virulence had higher adherence at first contact (about 16
). Strain B339 had a slower adherence at first contact (8
) than the others during the same period. The production of extracellular proteases, soluble extracellular factor(s) and extracellular antigen gP43 showed no correlation with the in vitro physiopathogenicity of the analyzed strains. We demonstrate that the Vero model presented in this paper is a suitable system to study infection and virulence in vitro. We are currently assessing its usefulness as a tool for the analysis of the interaction between pathogen, host and antifungal agents.
RESUMEN
A rapid method to evidence urease activity is described. Urea hydrolysis and consequent production ammonia are detected by a chemical reaction producing a blue phenol compound (indophenol blue). Three hundred and three yeast were tested. Out of 107 urease-positive organisms detected by Christensen's Urea Agar Test (CUAT) 102 were positive by our method. No false negatives were observed by this method when testing 87 Cryptococcus strains. Ths practical screening test for presumptive identification of Cryptococcus neoformans is simple, unaffected by pH changes and requires 15 minutes to be performed.