Coffee intake one hour prior to phlebotomy produces no clinically significant changes in routine biochemical test results.

Introduction: Although current guidelines recommend not drinking coffee prior to phlebotomy, our hypothesis is that drinking coffee does not affect the clinical interpretation of biochemical and haematological test results. Materials and methods: Twenty-seven volunteers were studied in basal state (T0) and 1h after (T1) drinking coffee. Routine haematological (Sysmex-XN1000 analyser) and biochemistry parameters (Vitros 4600 analyser) were studied. Results were compared using the Wilcoxon test (P < 0.05). A clinical change was considered when mean percent difference (MD%) was higher than the reference change value (RCV). Results: Coffee intake produced statistically, but not clinically, significant: i) increases in haemoglobin (P = 0.009), mean cell haemoglobin concentration (P = 0.044), neutrophils (P = 0.001), albumin (P = 0.001), total protein (P = 0.000), cholesterol (P = 0.025), high density lipoprotein cholesterol (P = 0.007), uric acid (P = 0.011), calcium (P = 0.001), potassium (P = 0.010), aspartate aminotransferase (P = 0.001), amylase (P = 0.026), and lactate dehydrogenase (P = 0.001), and ii) decreases in mean cell volume (P = 0.002), red cell distribution width (P = 0.001), eosinophils (P = 0.002), and lymphocytes (P = 0.001), creatinine (P = 0.001), total bilirubin (P = 0.012), phosphorus (P = 0.001), magnesium (P = 0.007), and chloride (P = 0.001). Conclusion: Drinking a cup of coffee 1 hour prior to phlebotomy produces no clinically significant changes in routine biochemical and haematological test results.

Nivel de conocimiento sobre la extracción de hemocultivos en enfermeras de la Unidad de Cuidados Intensivos / Level of Knowledge about Blood Culture Extractions in Intensive Care Unit Nurses

Introducción: El hemocultivo es una prueba sencilla, pero existe el riesgo de contaminación por un inadecuado procedimiento, en muchas ocasiones puede estar relacionado con la mala praxis del personal de enfermería. Objetivo: Valorar el nivel de conocimientos sobre la técnica de extracción de hemocultivo en enfermeras de una Unidad de Cuidados Intensivos. Métodos: Se realizó estudio descriptivo, transversal, en la Unidad de Cuidados Intensivos del Centro Nacional de Cirugía de Mínimo Acceso, La Habana, en enero 2021. La población estuvo conformada por 12 licenciadas en enfermería, se aplicó un cuestionario de conocimiento con la escala de puntuación: 0-30 puntos (no conocimiento); 31-60 puntos (poco conocimiento); 61-90 puntos (adecuado conocimiento), 91-100 puntos (excelente conocimiento). Se calcularon las frecuencias absolutas, porcentaje, prueba T para una muestra y chi cuadrado. Se utilizó el programa IBM SPSS versión 20 para Windows. Resultados: De la muestra estudiada, 41,70 por ciento consideró que el hemocultivo se realiza a pacientes febriles y el uso de guantes estériles como único medio de protección; 33,30 por ciento hizo referencia al alcohol como antiséptico cutáneo de elección; 58,30 % planteó que se inoculan con diez ml de sangre y 66,70 por ciento afirmó que se debe comenzar por el aeróbico. El promedio de puntuación general fue de 64,25. Conclusiones: Los profesionales de enfermería mostraron un adecuado conocimiento, los guantes estériles fueron el medio de protección más utilizado, destaca el uso de alcohol 76 por ciento para la desinfección de la piel, diez mililitros es el volumen de sangre considerado a inocular en los frascos, existe adherencia a los protocolos de transporte y conservación de la muestra(AU)

Introduction: Blood culture is a simple test, but there is a risk of contamination due to an inadequate procedure, which many times can be related to malpractice of the nursing personnel. Objective: To assess the level of knowledge about the blood culture extraction technique in nurses of an intensive care unit. Methods: A descriptive and cross-sectional study was carried out in the intensive care unit of the National Center for Minimal Access Surgery, Havana, in January 2021. The population consisted of twelve registered nurses. A knowledge questionnaire was applied, which included the following scoring scale: 0-30 points (no knowledge), 31-60 points (little knowledge), 61-90 points (adequate knowledge), 91-100 points (excellent knowledge). Absolute frequencies, percentage, T-test for one sample and chi-square were calculated. The program IBM SPSS (version 20) for Windows was used. Results: Of the sample studied, 41.70 percent considered that blood culture is performed on febrile patients and the use of sterile gloves as the only means of protection. 33.30 percent referred alcohol as the skin antiseptic of choice. 58.30 percent stated that test tube or flask inoculation is completed with 10 mL of blood. 66.70 percent stated that the technique should start with the aerobic. The average overall score was 64.25. Conclusions: Nursing professionals showed adequate knowledge. Sterile gloves were the most used means of protection. The use of 76 percent-alcohol for skin disinfection is relevant. The volume of blood to empty into the flask or sample tube is 10 mL. The protocols for sample preservation and transport are followed(AU)

Clinical assessment of acid-base balance in Netherland Dwarf rabbit / Avaliação clínica do equilíbrio ácido-básico em coelhos Anã Holandês

Pet rabbits have increased their popularity in a lot of countries. However, most of the laboratory profiles in rabbit medicine come from the observations made in rabbit as biomodels or meat production. So that further researches are necessary to obtain reference values for hematology and biochemical profiles in pet rabbits and the different breeds, especially, in relation to acid-base balance. The aim of this report was to offer the mean values of the main parameters connected with acid-base profile in Netherland Dwarf breed. Thirty-five healthy rabbits (15 males and 20 females) were studied. Venous blood sample from lateral saphenous vein was analyzed to measure: haematocrit, haemoglobin, blood urea nitrogen, glucose, blood pH, partial pressure of CO2 (pCO2), total CO2, ions bicarbonate, chloride, sodium, potassium, base excess and anion Gap. Results showed a shorter range that those reported by different researchers. Moreover, differences between genders were showed in pCO2, its values were higher in males. It may be associated with a greater cellular metabolism. Values obtained in this research should be taken into account by veterinary clinicians for this breed in their clinical assessments. Besides, these values provide new results in parameters with few reference values.(AU)

A popularidade de coelhos como animais de estimação aumentou em muitos países. No entanto, a maioria dos perfis de laboratório em medicina de coelhos advém das observações de biomodelos animais ou da produção de carne. Assim, são necessárias pesquisas adicionais para obter valores de referência para hematologia e perfis bioquímicos em coelhos de estimação, e das diferentes raças, especialmente, em relação ao equilíbrio ácido-base. O objetivo deste relatório foi oferecer os valores médios dos principais parâmetros ligados ao perfil ácido-base na raça Anã Holandês. Trinta e cinco coelhos saudáveis (15 machos e 20 fêmeas) foram estudados. A amostra de sangue venoso da veia safena lateral foi analisada para mensuração: hematócrito, hemoglobina, nitrogênio ureico sanguíneo, glicose, pH sanguíneo, pressão parcial de CO2 (pCO2), CO2 total, íons bicarbonato, cloreto, sódio, potássio, excesso de base e ânion Gap. Os resultados apresentaram um intervalo menor do que aqueles relatados por diferentes pesquisadores. Além disso, as diferenças entre os gêneros foram mostradas na pCO2, seus valores foram maiores no sexo masculino. Pode estar associado a um maior metabolismo celular. Os valores obtidos nesta pesquisa devem ser levados em consideração pelos clínicos veterinários para esta raça em suas avaliações clínicas. Além disso, esses valores fornecem novos resultados em parâmetros com poucos valores de referencia.(AU)

Clinical assessment of acid-base balance in Netherland Dwarf rabbit / Avaliação clínica do equilíbrio ácido-básico em coelhos Anã Holandês

Pet rabbits have increased their popularity in a lot of countries. However, most of the laboratory profiles in rabbit medicine come from the observations made in rabbit as biomodels or meat production. So that further researches are necessary to obtain reference values for hematology and biochemical profiles in pet rabbits and the different breeds, especially, in relation to acid-base balance. The aim of this report was to offer the mean values of the main parameters connected with acid-base profile in Netherland Dwarf breed. Thirty-five healthy rabbits (15 males and 20 females) were studied. Venous blood sample from lateral saphenous vein was analyzed to measure: haematocrit, haemoglobin, blood urea nitrogen, glucose, blood pH, partial pressure of CO2 (pCO2), total CO2, ions bicarbonate, chloride, sodium, potassium, base excess and anion Gap. Results showed a shorter range that those reported by different researchers. Moreover, differences between genders were showed in pCO2, its values were higher in males. It may be associated with a greater cellular metabolism. Values obtained in this research should be taken into account by veterinary clinicians for this breed in their clinical assessments. Besides, these values provide new results in parameters with few reference values.

A popularidade de coelhos como animais de estimação aumentou em muitos países. No entanto, a maioria dos perfis de laboratório em medicina de coelhos advém das observações de biomodelos animais ou da produção de carne. Assim, são necessárias pesquisas adicionais para obter valores de referência para hematologia e perfis bioquímicos em coelhos de estimação, e das diferentes raças, especialmente, em relação ao equilíbrio ácido-base. O objetivo deste relatório foi oferecer os valores médios dos principais parâmetros ligados ao perfil ácido-base na raça Anã Holandês. Trinta e cinco coelhos saudáveis ​​(15 machos e 20 fêmeas) foram estudados. A amostra de sangue venoso da veia safena lateral foi analisada para mensuração: hematócrito, hemoglobina, nitrogênio ureico sanguíneo, glicose, pH sanguíneo, pressão parcial de CO2 (pCO2), CO2 total, íons bicarbonato, cloreto, sódio, potássio, excesso de base e ânion Gap. Os resultados apresentaram um intervalo menor do que aqueles relatados por diferentes pesquisadores. Além disso, as diferenças entre os gêneros foram mostradas na pCO2, seus valores foram maiores no sexo masculino. Pode estar associado a um maior metabolismo celular. Os valores obtidos nesta pesquisa devem ser levados em consideração pelos clínicos veterinários para esta raça em suas avaliações clínicas. Além disso, esses valores fornecem novos resultados em parâmetros com poucos valores de referencia.

Clinical assessment of acid-base balance in Netherland Dwarf rabbit

Abstract Pet rabbits have increased their popularity in a lot of countries. However, most of the laboratory profiles in rabbit medicine come from the observations made in rabbit as biomodels or meat production. So that further researches are necessary to obtain reference values for hematology and biochemical profiles in pet rabbits and the different breeds, especially, in relation to acid-base balance. The aim of this report was to offer the mean values of the main parameters connected with acid-base profile in Netherland Dwarf breed. Thirty-five healthy rabbits (15 males and 20 females) were studied. Venous blood sample from lateral saphenous vein was analyzed to measure: haematocrit, haemoglobin, blood urea nitrogen, glucose, blood pH, partial pressure of CO2 (pCO2), total CO2, ions bicarbonate, chloride, sodium, potassium, base excess and anion Gap. Results showed a shorter range that those reported by different researchers. Moreover, differences between genders were showed in pCO2, its values were higher in males. It may be associated with a greater cellular metabolism. Values obtained in this research should be taken into account by veterinary clinicians for this breed in their clinical assessments. Besides, these values provide new results in parameters with few reference values.

Resumo A popularidade de coelhos como animais de estimação aumentou em muitos países. No entanto, a maioria dos perfis de laboratório em medicina de coelhos advém das observações de biomodelos animais ou da produção de carne. Assim, são necessárias pesquisas adicionais para obter valores de referência para hematologia e perfis bioquímicos em coelhos de estimação, e das diferentes raças, especialmente, em relação ao equilíbrio ácido-base. O objetivo deste relatório foi oferecer os valores médios dos principais parâmetros ligados ao perfil ácido-base na raça Anã Holandês. Trinta e cinco coelhos saudáveis (15 machos e 20 fêmeas) foram estudados. A amostra de sangue venoso da veia safena lateral foi analisada para mensuração: hematócrito, hemoglobina, nitrogênio ureico sanguíneo, glicose, pH sanguíneo, pressão parcial de CO2 (pCO2), CO2 total, íons bicarbonato, cloreto, sódio, potássio, excesso de base e ânion Gap. Os resultados apresentaram um intervalo menor do que aqueles relatados por diferentes pesquisadores. Além disso, as diferenças entre os gêneros foram mostradas na pCO2, seus valores foram maiores no sexo masculino. Pode estar associado a um maior metabolismo celular. Os valores obtidos nesta pesquisa devem ser levados em consideração pelos clínicos veterinários para esta raça em suas avaliações clínicas. Além disso, esses valores fornecem novos resultados em parâmetros com poucos valores de referencia.

¿Es necesario el ayuno para la determinación del perfil lipídico? / Is fasting necessary for the determination of the lipid profile?

El propósito de este estudio fue analizar los cambios post prandiales en el perfil lipídico en respuesta a una comida típica argentina. Se extrajo sangre a 33 mujeres voluntarias después de 12 h de ayuno (T0), 1 h después de un desayuno estandarizado (T1) y 1 h después de un almuerzo estandarizado (T2). Se midieron los niveles de: colesterol total, colesterol de lipoproteínas de alta densidad (C-HDL), colesterol de lipoproteínas de baja densidad (C-LDL) y triglicéridos. Los datos se analizaron utilizando la prueba t de Student pareada. Para cada analito se calculó la diferencia porcentual media (DM%) en T1 y T2 respecto de T0 y se comparó con el valor de referencia del cambio (VRC). Las DM% mayores al VRC se consideraron clínicamente significativas. En T1 y T2, los valores de C-HDL fueron más bajos que en T0, mientras que los valores de C-LDL en T1 fueron más bajos que en T0. Los niveles de triglicéridos fueron significativamente más altos en T1 que en T0. En todos los casos, la variabilidad fue estadísticamente significativa, aunque no clínicamente. En este estudio puede observarse que el perfil de lípidos en T1 y T2 no mostró diferencias clínicamente significativas con respecto a los valores basales.

The purpose of the present study was to analyze postprandial lipid profile changes in response to a typical Argentine meal. Blood was collected from 33 female volunteers after a 12 h fasting period (T0), 1 h after a standardized breakfast (T1) and 1 h after a standardized lunch (T2). The levels of total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides were measured. Data were analyzed using paired Student's t-test. Mean difference % (MD %) was calculated for each analyte at T1 and T2 and was further compared with reference change value (RCV). MDs % higher than RCV were considered clinically significant. At T1 and T2, HDL-C values were lower than at T0, whereas LDL-C values at T1 were lower than at T0. Triglycerides levels were significantly higher at T1 than baseline values. In all cases, variability was statistically, though not clinically, significant. This study demonstrates that at T1 and T2 lipid profile showed no clinically significant differences with respect to basal values.

O objetivo do presente estudo foi analisar as alterações do perfil lipídico pós-prandial em resposta a uma refeição típica argentina. O sangue foi coletado de 33 mulheres voluntárias após um período de jejum de 12 horas (T0),1 h após um café da manhã padronizado (T1) e 1 h após um almoço padronizado (T2). Foram medidos os níveis de: colesterol total (CT), colesterol HDL (C-HDL), colesterol LDL (C-LDL) e triglicérides. Os dados foram analisados utilizando o teste t de Student pareado. A diferença média% (DM%) foi calculada para cada analito em T1 e T2 e foi comparada com o valor de mudança de referência (VRC). Os MDs% maiores que o VRC foram considerados clinicamente significativos. Em T1 e T2, os valores de C-HDL foram menores que em T0, enquanto os valores de C-LDL em T1 foram menores que em T0. Os níveis de triglicérides foram significativamente maiores em T1 do que os valores basais. Em todos os casos, a variabilidade foi estatisticamente, embora não clinicamente, significativa. Este estudo demonstra que no perfil lipídico em T1 e T2 não houve diferenças clinicamente significativas em relação aos valores basais.

Fasting conditions: Influence of water intake on clinical chemistry analytes.

INTRODUCTION: Currently available recommendations regarding fasting requirements before phlebotomy do not specify any maximum water intake volume permitted during the fasting period. The aim was to study the effects of 300 mL water intake 1 h before phlebotomy on specific analytes. MATERIALS AND METHODS: Blood was collected from 20 women (median age (min-max): 24 (22 - 50) years) in basal state (T0) and 1 h after 300 mL water intake (T1). Glucose, total proteins (TP), urea, creatinine, cystatin C, total bilirubin (BT), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides (Tg), uric acid (UA), high-sensitivity C-reactive protein, gamma-glutamyl transferase (GGT), aspartate-aminotransferase (AST), alanine-aminotransferase and lactate-dehydrogenase (LD) were studied. Results were analyzed using Wilcoxon test. Mean difference (%) was calculated for each analyte and was further compared with reference change value (RCV). Only mean differences (%) higher than RCV were considered clinically significant. RESULTS: Significant differences (median T0vs median T1, P) were observed for TP (73 vs 74 g/L, 0.001); urea (4.08 vs 4.16 mmol/L, 0.010); BT (12 vs 13 µmol/L, 0.021); total cholesterol (4.9 vs 4.9 mmol/L, 0.042); Tg (1.05 vs 1.06 mmol/L, 0.002); UA (260 vs 270 µmol/L, 0.006); GGT (12 vs 12 U/L, 0.046); AST (22 vs 24 U/L, 0.001); and LD (364 vs 386 U/L, 0.001). Although the differences observed were statistically significant, they were not indicative of clinically significant changes. CONCLUSIONS: A water intake of 300 mL 1 h prior to phlebotomy does not interfere with the analytes studied in the present work.

Reference database of hematological parameters for growing and aging rats.

The normal hematological values in various phases of the rat life provide a valuable guide to researchers and could be useful for experimental works. However, database information available on the literature are incomplete. AIM: This study aimed to present normal hematological parameters of young and aged rats. METHODS: Male and female rats were distributed into seven experimental groups with 1, 2, 3, 6, 12, 18, and 24 months of age. Blood samples taken from the tails were analyzed. Normal hematological values were determined for each age group. RESULTS: Rats showed a progressive weight gain with advancing age, predominantly after 3 months of life. With advancing age, differences were found on hematological parameters: some of them showed a progressive rise with age and others did not. Hemoglobin levels and hematocrit did not change while the number of circulating red blood cells suffered slight increase. CONCLUSION: The present study determined the normal values for absolute and relative hematological parameters in Wistar rats from 2 to 24 months for male and female rats. The results can be used in studies of effects of aging, feeding, and medications on growing and aging rats.

Clinical assessment of acid-base balance in Netherland Dwarf rabbit

Abstract Pet rabbits have increased their popularity in a lot of countries. However, most of the laboratory profiles in rabbit medicine come from the observations made in rabbit as biomodels or meat production. So that further researches are necessary to obtain reference values for hematology and biochemical profiles in pet rabbits and the different breeds, especially, in relation to acid-base balance. The aim of this report was to offer the mean values of the main parameters connected with acid-base profile in Netherland Dwarf breed. Thirty-five healthy rabbits (15 males and 20 females) were studied. Venous blood sample from lateral saphenous vein was analyzed to measure: haematocrit, haemoglobin, blood urea nitrogen, glucose, blood pH, partial pressure of CO2 (pCO2), total CO2, ions bicarbonate, chloride, sodium, potassium, base excess and anion Gap. Results showed a shorter range that those reported by different researchers. Moreover, differences between genders were showed in pCO2, its values were higher in males. It may be associated with a greater cellular metabolism. Values obtained in this research should be taken into account by veterinary clinicians for this breed in their clinical assessments. Besides, these values provide new results in parameters with few reference values.

Resumo A popularidade de coelhos como animais de estimação aumentou em muitos países. No entanto, a maioria dos perfis de laboratório em medicina de coelhos advém das observações de biomodelos animais ou da produção de carne. Assim, são necessárias pesquisas adicionais para obter valores de referência para hematologia e perfis bioquímicos em coelhos de estimação, e das diferentes raças, especialmente, em relação ao equilíbrio ácido-base. O objetivo deste relatório foi oferecer os valores médios dos principais parâmetros ligados ao perfil ácido-base na raça Anã Holandês. Trinta e cinco coelhos saudáveis (15 machos e 20 fêmeas) foram estudados. A amostra de sangue venoso da veia safena lateral foi analisada para mensuração: hematócrito, hemoglobina, nitrogênio ureico sanguíneo, glicose, pH sanguíneo, pressão parcial de CO2 (pCO2), CO2 total, íons bicarbonato, cloreto, sódio, potássio, excesso de base e ânion Gap. Os resultados apresentaram um intervalo menor do que aqueles relatados por diferentes pesquisadores. Além disso, as diferenças entre os gêneros foram mostradas na pCO2, seus valores foram maiores no sexo masculino. Pode estar associado a um maior metabolismo celular. Os valores obtidos nesta pesquisa devem ser levados em consideração pelos clínicos veterinários para esta raça em suas avaliações clínicas. Além disso, esses valores fornecem novos resultados em parâmetros com poucos valores de referencia.

Non-invasive genetic sampling for molecular sexing and microsatellite genotyping of hyacinth macaw (Anodorhynchus hyacinthinus).

Molted feather sampling is a useful tool for genetic analyses of endangered species, but it is often very laborious due to the low quality and quantity of the DNA obtained. In the present study we show the parts of feathers that resulted in better yield of DNA. In descending order these were: blood clot outside the umbilicus, umbilicus (without blood clot), tip, inner membrane, and small calamus. Compared to DNA extracted from blood samples, DNA extracted from feathers produced microsatellite alleles of poorer quality and had to be processed immediately after extraction. As expected due to the level of DNA degradation, molecular sexing protocols that result in shorter PCR products were more efficient.

Capillary blood glucose and venous blood glucose measured with portable digital glucometer in diabetic dogs

This study aimed to compare the glycemic values obtained with a glucometer with those determined by a colorimetric enzymatic assay in venous blood as well as to evaluate the possibility of using capillary blood samples of dogs with diabetes mellitus. A group with 30 diabetic dogs was formed and from each dog three blood samples were obtained for glycemic evaluations by different methods and blood collection sites. The mean glycemic values showed no significant difference between the different sites of blood collection and methods (P=0.90). Venous, pinna and carpal pad blood glucose showed excellent correlation with the colorimetric enzymatic assay (r=0.98; r=0.95 and r=0.96 respectively) and the obtained values fit properly the clinically acceptable intervals in the error grid analysis. The present study revealed that carpal pad, venous and pinna glucose measurements are clinically acceptable and this method is feasible for use in hospitalized diabetic dogs. The sample attainment of carpal pad proved to be effective and a viable alternative. Further work is necessary to assess the utility of this technique in a home environment.

Capillary blood glucose and venous blood glucose measured with portable digital glucometer in diabetic dogs

This study aimed to compare the glycemic values obtained with a glucometer with those determined by a colorimetric enzymatic assay in venous blood as well as to evaluate the possibility of using capillary blood samples of dogs with diabetes mellitus. A group with 30 diabetic dogs was formed and from each dog three blood samples were obtained for glycemic evaluations by different methods and blood collection sites. The mean glycemic values showed no significant difference between the different sites of blood collection and methods (P=0.90). Venous, pinna and carpal pad blood glucose showed excellent correlation with the colorimetric enzymatic assay (r=0.98; r=0.95 and r=0.96 respectively) and the obtained values fit properly the clinically acceptable intervals in the error grid analysis. The present study revealed that carpal pad, venous and pinna glucose measurements are clinically acceptable and this method is feasible for use in hospitalized diabetic dogs. The sample attainment of carpal pad proved to be effective and a viable alternative. Further work is necessary to assess the utility of this technique in a home environment.(AU)

Diagnóstico molecular de histoplasmosis humana en muestras de sangre entera / Molecular diagnosis of human histoplasmosis in whole blood samples

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.