RESUMEN
Essential oils have been proposed as alternatives to antibiotic use in food animal production. This study evaluated 3 chemotypes of the Origanum genus, containing varying amounts of secondary metabolites carvacrol, thymol, and sabinene, in the broiler chicken diet. Aerial parts of Origanum vulgare L. (OL), O. vulgare L. ssp. hirtum (OH), and O. majorana (OM) were collected from a greenhouse located in the high altitude Sabana de Bogotá (Savanna of Bogotá) and O. vulgare L. ssp. hirtum (OG) produced and ground in Greece. Oregano essential oils (OEO) from these plants were obtained by steam distillation and analyzed by gas chromatography coupled to a mass spectrometer. Six treatments were evaluated: 200 mg/kg of OEO from OH, OL, and OM, 50 mg/kg of OEO from OG, 500 mg/kg of chlortetracycline, and without additives. Broiler chicks were maintained at 2,600 m above sea level, placed in brooder cages under a completely randomized design. Template DNA was isolated from duodenal, jejunal, ileal, and cecal contents in each group and bacterial 16S rDNA patterns were analyzed by denaturing gradient gel electrophoresis. Dendrograms of denaturing gradient gel electrophoresis band patterns revealed 2 main clusters, OEO-treated chicks and nontreated control chicks, in each intestinal segment. Band patterns from different gut compartments revealed major bacterial population shifts in the foregut (duodenum, jejunum, and ileum) compared with the hindgut (cecum and colon) at all ages evaluated (P < 0.05). The OEO groups showed less shift (62.7% similarity coefficient) between these 2 compartments versus the control groups (53.7% similarity coefficient). A reduction of 59% in mortality from ascites was seen in additive-supplemented groups compared with the control group. This study represents the first work to evaluate the effects of the 3 main chemotypes of Origanum genus in broilers.
Asunto(s)
Pollos/microbiología , Intestinos/microbiología , Microbiota/efectos de los fármacos , Aceites Volátiles/farmacología , Origanum/química , Alimentación Animal/análisis , Animales , Antibacterianos/farmacología , Pollos/metabolismo , Colombia , Cimenos , Electroforesis en Gel de Gradiente Desnaturalizante/veterinaria , Dieta/veterinaria , Suplementos Dietéticos/análisis , Grecia , Incidencia , Masculino , Monoterpenos/farmacología , Origanum/genética , Distribución Aleatoria , Timol/farmacologíaRESUMEN
The rapid increase of penicillin-resistant Streptococcus pneumoniae isolates could be a consequence of the spread of clones or due to the antimicrobial selective pressure. The genetic relatedness of 190 invasive isolates S. pneumoniae with reduced susceptibility to penicillin recovered from Colombian children less than 5 years old during a surveillance study from 2000 to 2003 was determined by the use of pulsed-field electrophoresis (PFGE). Overall, 42 different PFGE patterns were identified, but 4 of them included 76% of all isolates. They were related with international clones 1-Spain23F, 2-Spain6B, 3-Spain9V and 26-Colombia23F. Our results indicated that the dissemination of penicillin-resistant S. pneumoniae was the result of the spread of international clones, specially, the 3-Spain9V clone.
Asunto(s)
Resistencia a las Penicilinas , Infecciones Neumocócicas/microbiología , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/patogenicidad , Antibacterianos/uso terapéutico , Preescolar , Colombia/epidemiología , Femenino , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Biología Molecular , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/epidemiología , Serotipificación , Streptococcus pneumoniae/clasificaciónRESUMEN
El incremento de aislamientos de Streptococcus pneumoniae resistentes a la penicilina se favorece por la presión selectiva del antibiótico y la dispersión clonal. Como parte del programa de vigilancia molecular, por medio del uso de la electroforesis en campo pulsado (PFGE), se determinaron las relaciones genéticas de 190 aislamientos invasores de S. pneumoniae con susceptibilidad disminuida a la penicilina recuperados de niños colombianos menores de 5 años durante los años 2000-2003. Se identificaron 42 diferentes patrones electroforéticos; cuatro patrones agruparon el 76 por ciento de los aislamientos, los cuales se encontraron relacionados con los clones internacionales 1-España 23F , 2-España 6B , 3-España 9V y 26-Colombia 23F . Nuestros resultados indican que la diseminación de S. pneumoniae resistente a la penicilina es el resultado de la dispersión de clones internacionales, especialmente, del clon 3-España 9V