Las observaciones microscópicas de los microorganismos, como bacterias, suelen hacerse con objetivos de mayor aumento y de inmersión. Las fotomicrografías con aquellos microscopios que tienen incorporada una cámara fotográfica, permiten usualmente visualizar los microorganismos en dos planos y las imágenes generalmente a 1000 aumentos. Éstas se encuentran principalmente en un atlas o como fotografías sueltas ilustrando manuales. Las imágenes a más de 1000 aumentos suelen requerir el uso de microscopios electrónicos de transmisión o de barrido (scanning). Con este último se obtiene imágenes tridimensionales, en muchos casos de gran ayuda para el mejor conocimiento de los microorganismos.

Objetivos: Conocer la prevalencia de Arcobacter en niños y adultos con/sin diarrea y en animales: aves, ganado vacuno y porcino, peces y mariscos. Diseño: Estudio transversal descriptivo. Institución: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, UNMSM, Instituto Nacional de Salud del Niño, Instituto Materno Infantil de San Bartolomé y Hospital Arzobispo Loayza. Material biológico: Aislamientos bacterianos de humanos y animales. Intervenciones: Búsqueda activa de Arcobacter sp. en humanos y animales. Principales medidas de resultados: Porcentajes. Resultados: De 197 niños incluidos en el estudio, 100 tenían diarrea y de estos en dos (2%) se aisló A. butzleri; entre los niños sin diarrea, no se aisló el germen. De 232 adultos, 52 tuvieron diarrea y 180 no; el único aislamiento se obtuvo de este último grupo. Los animales con mayor prevalencia de Ar...

A prospective study was performed in 108 hospitalized children younger than 2 years old from May 1994 to June 1995. Urine specimens obtained through suprapubic aspiration were assessed for nitrite, leukocyte esterase and leukocyturia. Quantitative urine culture was the reference test employed. Prevalence of urinary tract infection was 10% (11 of 108 patients). Sensitivity and negative predictive values were 100% for leukocyte esterase (cut-point criterion 10-25 leukocytes/ul) or for nitrite these same thresholds were used. For leukocyte esterase with positivity criterion of 500 leukocytes/ul, sensitivity and positive predictive values were 82% and 100%, respectively. Nitrite with threshold excluding slight color changes yield sensitivity of 91% and positive predictive value of 43%. Both specificity and negative predictive values remained high for either nitrite or leukocyte esterase with...

50 cases of patients who had preterm labor is studied. Careful not to include cases where the cause of prematurity was evident (twins, polyhydramnios, hemorrhagic cases) were reported. Urine culture sample was taken by bladder catheterization in the first 48 hours postpartum. Parallel monitoring 50 cases of patients whose delivery was at term, and also was made urine culture is studied. It was obtained obvious differences in both groups. In the group studied was 20% positive urine cultures, against 10% in the control group. The predominant germ was E. coli. The perinatal mortality in the study group was 20%, ten times higher than the control group. It is recommended that urine cultures routinely performed in all cases of preterm labor.

50 cases of patients who had preterm labor is studied. Careful not to include cases where the cause of prematurity was evident (twins, polyhydramnios, hemorrhagic cases) were reported. Urine culture sample was taken by bladder catheterization in the first 48 hours postpartum. Parallel monitoring 50 cases of patients whose delivery was at term, and also was made urine culture is studied. It was obtained obvious differences in both groups. In the group studied was 20% positive urine cultures, against 10% in the control group. The predominant germ was E. coli. The perinatal mortality in the study group was 20%, ten times higher than the control group. It is recommended that urine cultures routinely performed in all cases of preterm labor.

La fasciolosis humana es una de las enfermedades parasitarias más importantes en el Perú debido a las altas tasas de prevalencia reportadas en los últimos años principalmente en el trapecio andino. El grupo etáreo más comprometido es en los niños y las manifestaciones clínicas de la enfermedad pueden ser diversas. En el presente estudio reportamos siete casos de fasciolosis humana diagnosticados en el Instituto Especializado de Salud del Niño (IESN), Lima, Perú, entre los años 1988 y 2003. De 168 historias clínicas revisadas con el diagnóstico final de parasitosis, 7 niños (2 hombres y 5 mujeres) entre 2 y 14 años (media ± DS: 8.52 ± 1.43) correspondieron a fasciolosis diagnosticados por exámenes parasitológicos y/o serológicos. Seis de los siete casos procedían de zonas ganaderas tales como Cajamarca, Ancash, Huancavelica y Junín. Los signos clínicos más frecuent...

In the present research we evaluated the antibacterial and antifungical activity of marine actinomycetes over pathogen of clinical origin. Likewise, it was evaluated the capacity to produce extracellular enzymes like carbohidrases, lipases and proteases. The Actinomycetes were isolated from sediments collected between September to December 2005 of Ancón (Lima) and Independencia (Ica) Bays at depths of 34 and 100 m. The isolation was performed in Casein - Starch Agar (CSA) and Marine Agar (AM) with addition of Cicloheximide (10 μg/mL). The antimicrobial evaluations were done comparing them with pathogenic antibiotic-multiresistant bacteria and fungi from clinical origin; in as much, to evaluate their multienzimatic activity several polimeric substrates were used. A total of 62 actinomycetes were isolated, 31 of there (50%) showed antibacterial activity in opposite to Staphylococcus aure...

Objectives: To identify isolated S. pneumoniae serotypes correlating them with those covered by existing vaccines and determining antimicrobial resistance. Design: Descriptive, observational and longitudinal study. Setting: Daniel A Carrion Tropical Medicine Institute, School of Medicine, UNMSM. Biologic material: Streptococcus pneumoniae stocks. Interventions: Forty Streptococcus pneumoniae stocks isolated between 2002 and 2006 were serotyped at Carlos III Health Institute in Madrid, Spain; 15 were invasive, 11 isolated from localized infections, 6 from carriers and 8 were multiresistant. Main outcome measures: Protection of local existing vaccines to Streptococcus pneumoniae infections. Results: There were 14 different serotypes and most identified groups were 23, 19 and 6, 28,6% contained in the 7–valent vaccine, 42,9% in the 9-valent, 50% in the 11-valent and 71,4% in the 23-valent...

En el presente trabajo evaluamos la actividad antibacteriana y antifúngica de actinomycetes marinos sobre patógenos de origen clínico. Asimismo, fueron evaluadas la capacidad de producir enzimas extracelulares como carbohidrasas, lipasas y proteasas. Los Actinomycetes fueron aislados de sedimentos colectados entre setiembre a diciembre del 2005 de las Bahías de Ancón (Lima) e Independencia (Ica) de 34 y 100 m de profundidad. El aislamiento se realizó en Agar Caseína - Almidón (ACA) y Agar Marino (AM) con adición de Cicloheximide (10 μg/mL). Las evaluaciones antimicrobianas fueron realizadas frente a bacterias patógenas antibiótico-multirresistentes y hongos de origen clínico; en tanto, para evaluar su actividad multienzimática se utilizaron sustratos poliméricos diversos. Se aislaron un total de 62 actinomycetes, de los cuales 31 (50%) mostraron actividad antibacteriana fr...

Staphylococcus aureus es un importante patógeno involucrado en una serie de infecciones e intoxicaciones, presenta múltiples factores de virulencia y su impacto se incrementa por su notable resistencia a los antimicrobianos. Objetivo: Determinar la frecuencia de Staphylococcus aureus meticilino resistente adquiridos en la comunidad, en hospitales de Lima- Perú. Material y métodos: Se realizó un estudio descriptivo multicéntrico. La resistencia a meticilina se determinó por el método Oxacillin Agar Screen. El origen de la cepa fue determinado mediante los criterios de los CDC; la Leucocidina de Panton Valentine fue identificada por métodos moleculares. Resultados: Se aislaron 276 cepas de Staphylococcus aureus, 160 fueron resistentes a meticilina (58%), 9 de ellas fueron identificadas como adquiridas en la comunidad (5,6%). La PVL fue identificada en 25 cepas (9,1%), 14 fueron MS...

OBJECTIVE: To determine Aeromonas importance as diarrhea agent in children less than 5 year- old and compare its frequency with other enteropathogens. MATERIAL AND METHODS: Between 1998 and 1999 285 fecal samples were taken from children with acute diarrhea in 5 hospitals, which were then sent to “Daniel A. Carrión” Institute of Tropical Medicine in Cary Blair’s transportation medium for processing by Aerokey II method. RESULTS: Aeromonas was the most frequent bacteria isolated among enteropathogens, mainly in children less than 2-year old and in summer, and Aeromonas caviae was the most frequent species. Aeromonas was mainly isolated in agar TCBS, employing O/129 disks to differentiate it from Vibrio cholerae. All Aeromonas were sensitive in vitro to furazolidone and neomycin. CONCLUSIONS: Aeromonas was the main etiological agent of aquous acute diarrhea in children less than 5 year...

OBJECTIVE: To determine the most frequent bacteria causing infection in hospitalized newborns, and their antimicrobial sensitivity. MATERIAL AND METHODS: Review of the clinical files of Neonatology Division, Children’s Health Institute (Lima, Peru) and identification of the positive cultures and antibiograms from June 1999 until May 2002. RESULTS: During this three year period there were 94 patients with confirmed sepsis from whom 161 samples were obtained (blood, urine, IV catheters, and others ). The most frequently isolated bacteria were: Staphylococcus epidermidis (38,3%), Staphylococcus aureus (12%), Klebsiella sp (10%), Alcaligenes fecalis (4,6%), Acinetobacter sp (4%) and Pseudomonas aeruginosa (4%). S. epidermidis showed 100% sensitivity to vancomycin, 90% to cefotaxime, 50% to amikacin and ampicillin and 37% to oxacillin. Klebsiella showed 100% sensitivity to ciprofloxacin and...

Objetivos: Determinar la efectividad antibacteriana de diez plantas medicinales frente a Streptococcus pneumoniae. Diseño: Estudio experimental Institución: Instituto de Medicina Tropical, UNMSM. Material biológico: Aislamientos bacterianos de Streptococcus pneumoniae, plantas medicinales. Intervenciones: Los extractos de 10 plantas medicinales fueron puestos en contacto in vitro mediante el método de disco difusión con 10 cepas de Streptococcus pneumoniae. Principales medidas de resultados: Actividad de las plantas medicinales sobre las cepas de Streptococcus pneumoniae. Resultados: Almendro y Bellaco caspi fueron las únicas plantas que dieron pequeño halo de inhibición con algunas cepas; con almendro se inhibió 2 cepas y con Bellaco caspi se inhibió 7 cepas y 3 resultaron resistentes. Estos resultados no tuvieron relación con el serotipo del neumococo ni con los antibiótico...

Objective: To identify Malassezia species in healthy skin seborrhea areas in Lima inhabitants. Design: Cross-sectional study. Setting: Daniel Alcides Carrion Tropical Medicine Institute, Universidad Nacional Mayor de San Marcos, Lima, Peru. Participants: Asymptomatic persons. Interventions: Skin samples were collected from 129 asymptomatic residents of several districts of Lima city using Mariat and Adan-Campos’ technique. Malassezia isolation was performed in modified Dixon medium and incubated at 32° C for 7 days. Colonies were identified by macro and micro morphological characteristics and typing was determined by biochemical and physiological properties using Guillot’s technique. Main outcome measures: Malassezia species, participants’ gender, age and anatomical region. Results: Malassezia spp was isolated in 43.4% of the residents, 49.2% in men and 37.5% in women. From variou...