RESUMEN
Some metabolic peculiarities of bacteria of the genus Klebsiella were investigated. The bacteria under study were isolated from different sources and varied in virulence. The pathogenic and saprotrophic enterobacteria were discriminated based on their response to the addition of carbohydrates or nitrate to the medium. Pathogenic Klebsiella spp. exhibited mainly the mixed formic-acid type of fermentation and were more resistant to nitrates than saprotrophic bacteria with the butanediol type of fermentation. The bacteria Klebsiella pneumoniae subsp. pneumoniae isolated from different sources, such as patients, healthy persons, or the environment, exhibited no substantial differences in metabolism and virulence. It was inferred that these bacteria themselves cannot cause disease, and their isolation in morbid states is an indirect result of dysbacteriosis.
Asunto(s)
Klebsiella/metabolismo , Metabolismo de los Hidratos de Carbono , Fermentación , Klebsiella/patogenicidad , Nitratos/metabolismo , Especificidad de la Especie , VirulenciaRESUMEN
No trustworthy distinctions were revealed under the comparative analysis of properties of bacteria of Citrobacter genus from 3 studied ecological groups (from patients with diarrhea, from healthy persons and patients with extraenteric pathological process). It allows the finding of potentially partogenic bacteria of Citrobacter genus in patients with diarrhea to be considered the manifestation of dysbacteriosis.
Asunto(s)
Citrobacter/patogenicidad , Antibacterianos/farmacología , Adhesión Bacteriana , Citrobacter/efectos de los fármacos , Citrobacter/aislamiento & purificación , Citrobacter/metabolismo , Diarrea/microbiología , Sistema Digestivo/microbiología , Hemólisis , Humanos , Pruebas de Sensibilidad Microbiana , Factores de TiempoRESUMEN
While comparatively analyzing the properties of Klebsiella pneumoniae from three studied sources (patients, healthy people, environment), no reliable differences between the comparable strains have been revealed. No differences have been found in the toxin formation, hemagglutinating and antilysozymic activity, adhesivity and invasive properties as well as in the peculiarities of gas exchange, while growing on media with different nitrogen and carbon sources. The studied microorganisms differed only in antibiotic resistance: strains isolated from the environment were sensitive to antibiotics, whereas strains of human origin were resistant to them.
Asunto(s)
Klebsiella pneumoniae/fisiología , Antibacterianos/farmacología , Adhesión Bacteriana , Células Cultivadas/microbiología , Medios de Cultivo , Microbiología Ambiental , Humanos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/aislamiento & purificación , Klebsiella pneumoniae/patogenicidad , Pruebas de Sensibilidad Microbiana , Muramidasa/antagonistas & inhibidores , Factores de TiempoRESUMEN
In vitro experiments have demonstrated that the lactoperoxidase system produces a bactericidal effect on salmonellae and shigellae. The physiological concentrations of the components of this system, making it possible to obtain a pronounced bactericidal effect, have been established. Lactobacilli have been shown to potentiate the effect of the lactoperoxidase system. The possibility of realizing the bactericidal properties of the lactoperoxidase system with respect to salmonellae and shigellae in the preparations of immune lactosera, intended for passive enteral immunization against intestinal infections, has been suggested.
Asunto(s)
Lactoperoxidasa/inmunología , Peroxidasas/inmunología , Salmonella/inmunología , Shigella sonnei/inmunología , Medios de Cultivo/metabolismo , Relación Dosis-Respuesta a Droga , Peróxido de Hidrógeno/metabolismo , Lactobacillus/enzimología , Lactobacillus/inmunología , Salmonella/crecimiento & desarrollo , Salmonella typhimurium/crecimiento & desarrollo , Salmonella typhimurium/inmunología , Shigella sonnei/crecimiento & desarrollo , Factores de TiempoRESUMEN
The protective properties of the mammary gland secretions of cows immunized with Shigella sonnei into the udder were studied. As a model for this study the intranasal and intraperitoneal infection of white mice was used. Immune milk was found to have pronounced protective properties against S. sonnei. When introduced intraperitoneally, this milk protected the animals infected with S. sonnei from death. When introduced intranasally, it not only protected the animals from death, but perceptibly inhibited the development of the pathological process in the pulmonary tissue, preventing the multiplication of shigellae and accelerating the elimination of the infective agents from the lungs of the infected animals. As a rule, the degree of protective action was determined by the level of antibodies to shigellae in the substrate under test.
Asunto(s)
Anticuerpos Antibacterianos/inmunología , Leche/inmunología , Shigella sonnei/inmunología , Animales , Anticuerpos Antibacterianos/análisis , Especificidad de Anticuerpos , Bovinos , Calostro/inmunología , Disentería Bacilar/prevención & control , Femenino , Inmunización Pasiva , RatonesRESUMEN
The influence of parenteral immunization with live virulent vibrios and lipopolysaccharide-containing choleragen toxoid and oral immunization with liver avirulent vibrios on the interaction of V. eltor and the mucous membrane was studied on the ligated loops of the small intestine in 164 rabbits. Protection from enterotoxigenicity (the accumulation of fluid) was compared with the suppressive effect on the adhesion and colonization of vibrios. The coefficient of immunization efficacy was determined microbiologically, as the ratio of the adhesion index (i. e. the percentage of the number of vibrios in the media inoculated with the homogenized matter of the washed intestinal wall from the sum of this number and the amount of vibrios in the contents) in the control rabbits to the adhesion index in the immunized ones, and histologically, as the ratio of the average number of vibrios attached to the epithelial number of vibrios attached to the epithelial cells of one intestinal villus in the control rabbits to the corresponding number in the immunized animals. Protection from the enterotoxigenicity of vibrios resulted from the suppression of their adhesion and colonization, lipopolysaccharide being, probably, the factor of adhesiveness. Effective protection was accompanied by an increase in the number of lymphocytes (especially "granular" lymphocytes with lysosome-like granules) between intestinal villi and the number of lymphoid and plasmic cells in the lamina propria of the villi, which indicates the role of lymphocytes in cholera-induced immunity.
Asunto(s)
Toxina del Cólera/inmunología , Intestino Delgado/microbiología , Vibrio cholerae/fisiología , Adhesividad , Animales , Inmunización , Esquemas de Inmunización , Intestino Delgado/citología , Intestino Delgado/inmunología , Recuento de Leucocitos , Linfocitos/citología , Conejos , Factores de Tiempo , Vibrio cholerae/inmunologíaRESUMEN
Light and electron microscope studies in ligated rabbit gut loops showed that cholera vibrios El Tor attached themselves to the enterocytes and multiplied, most probably on the intestinal epithelium surface. But they did not penetrate deeper and were unable to cause destruction of the epithelium or marked inflammation. Ultrastructural manifestations of both apocrine and merocrine secretion of the enterocytes were observed. In addition, the enterocytes showed signs of generally enhanced activity. Some other changes and alterations in the lamina propria, presumably induced by excessive transport of water, are also described. The enterotoxin-induced epithelial hypersecretion with fluid accumulation in the gut loops resulted in the attached vibrios being cleared off the epithelium lining into the gut lumen. NAG vibrios were mostly incapable of inducing the above changes. We discuss the importance of cholera vibrio attachment to and its multiplication on the intestinal epithelium in the pathogenesis of cholera.