Rafael Monge

Rotavirus and Hepatitis A virus in market lettuce (Latuca sativa) in Costa Rica

We assessed the presence of rotavirus and Hepatitis A virus in lettuce bought in farmer markets from San José, Costa Rica, during months of low (April-June) and high (December-January) incidence of diarrhea associated with rotavirus, respectively. Lettuce samples were pooled and evaluated for rotavirus by enzyme-linked immunosorbent assay (ELISA) and for Hepatitis A virus by radioimmunoassay, polymerase chain reaction (PCR) and electron microscope. Three sample pools, collected during the period of high prevalence of diarrhea, were positive for rotavirus by ELISA and in one of them rotavirions were visualized by electron microscopy. Two samples pools collected during the same period were positive for Hepatitis A virus as shown by PCR. In almost all the pools fecal coliform bacteria were detected by cultivation and bacteriophages were visualized by electron microscopy.

Contamination of bovine milk with residues of inhibitory substances in Costa Rica

Inflorescences of Baclris gasipaes (a moooecioos neolropica1 pahn) present a strong prezigotic resource allocation toward masculinity on the inflorescence. Male reproductive effort (ERM. biomass) was 0.82 ± 0.11 g male flowers / g inflorescence. A high conelatioo between me total inflorescence biomass with female reproductive effort (ERF) (r= 0.76), indicates that plants wim bigger inflorescences allocate more resources to ihe female functioos. The pistillate flowers are situated preferentially in me inner pans of rachillas. Early ideas about evolution of protoginy, resource allocation and plant sexual systems are supported by these data.

Patrón de sensibilidad a antibióticos de bacterias Gram negativas aisladas a partir de fórmulas enterales

Introduccion. Las formulas enterales contaminadas representan un riesgo para el desarrollo de infecciones nosocomiales y de pacientes hospitalarios. El objetivo de este estudio fue identificar 75 cepas de bacilos Gram negativos, aislados a partir de formulas enterales, distribuidas en los tres mayores centros hospitalarios costarricenses y evaluar su patron de sensibilidad a los antibioticos. Material y metodos. Se utilizaron dos tecnicas diferentes para el desarrollo del proyecto: la tecnica modificada de Kirby Bauer y la tecnica ATB antibiograma (Biomeriaux®). Resultados. A partir de las muestras analizadas, los grupos predominantes fueron Aeromonas sp., (22,7%), Klebsiella sp. y Proteus sp. (18,7% cada una) y Enterobacter sp. (4%). De acuerdo a los patrones de sensibilidad a los antibioticos obtenidos usando la tecnica de Kirby-Bauer modificada, 36% de las cepas mostraron resistencia a amoxicilinaacido clavulanico, 25,3% a cefaclor y 14,7% a cefuroxime. Todas las cepas fueron sensibles a imipenem y ciprofloxacina. Utilizando la tecnica ATB antibiograma, las bacterias mostraron resistencia a la amoxicilina (74,6%), amoxicilinaacido clavulanico (34,6%), ticarcilina-cefalotina (22,6%) y piperacilina (2,6%). Todas las cepas fueron sensibles a los otros diez antibioticos evaluados. Conclusiones. Es urgente asegurar una higiene estricta durante la preparacion y manejo de las soluciones enterales utilizadas en los hospitales, de manera que no representen un foco potencial de contaminacion con bacterias resistentes que puedan limitar la recuperacion de los pacientes.