RESUMEN
The interaction between lead, copper, cadmium and zinc in their binary combinations was investigated in Indian mustard seedlings (Brassica juncea L. var. Malopolska). Fourteen-days-old seedlings were treated with Pb(NO3)2, CuSO4, CdCl2, ZnSO4 at 50µmol of metal ion concentration and at 25µmol of each metal ion in combinations. Metal combinations were generally more inhibiting in terms of biomass production. This inhibiting effect followed an order: Cu+Cd>Cu+Zn, Cd+Pb>Cu+Pb>Zn+Pb, Cu>Cd>Zn>Zn+Cd>Pb. We observed synergistic and antagonistic effects of metal uptake in binary metal treatments, suggesting metal crosstalk at the plant uptake site. Metal content in plant tissues varied among different combinations. The metal concentrations followed an order of Pb>Cu>Zn>Cd in roots, Zn>Cu>Pb>Cd in the stem and Zn>Cu>Cd>Pb in leaves. Presence of metals altered the distribution of micronutrients (Cu, Zn) in plants: Cu concentration was lowered in roots and leaves and increased in stems; Zn content was increased in plants, with stems having up to 4 or 5 times more Zn than in control plants.
Asunto(s)
Cadmio/metabolismo , Cobre/metabolismo , Plomo/metabolismo , Planta de la Mostaza/metabolismo , Zinc/metabolismo , Biomasa , Clorofila/metabolismo , Glutatión/metabolismo , Raíces de Plantas/metabolismo , Brotes de la Planta/metabolismo , Tallos de la Planta/metabolismo , Distribución TisularRESUMEN
INTRODUCTION: Many pathogenic bacterial species have the ability to biofilm formation. In our study we determined the influence of Lactobacillus casei on biofilm formation by enteroaggregative Escherichia coli (EAEC) strains obtained from irritable bowel syndrome patients. METHODS: The ability of EAEC isolates to biofilm formation was assessed in the presence of various concentrations of the probiotic L. casei strain in an a semi- quantitative microtitre plate assays under culture conditions, similar to those prevailing in the human intestine. RESULTS: Depending on the concentrations L. casei inhibited biofilm formation of the majority (> 80%) of the EAEC strains. Concentration of 4.5 x 10(7) cfu/ml of L. casei was the most effective inhibitory dose, although a few strains (approximately 18%) formed the biofilm regardless of the presence and concentration of the probiotic L. casei strain. CONCLUSION: The inhibitory effect of L. casei on biofilm formation at most of studied EAEC strains suggest that L. casei may reduce the risk of developing persistent intestinal infections in humans.
Asunto(s)
Biopelículas/crecimiento & desarrollo , Escherichia coli/fisiología , Intestinos/microbiología , Síndrome del Colon Irritable/microbiología , Lacticaseibacillus casei/fisiología , Interacciones Microbianas , Adhesión Bacteriana , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/microbiología , Humanos , Lacticaseibacillus casei/clasificación , Lacticaseibacillus casei/aislamiento & purificación , Especificidad de la EspecieRESUMEN
Enteropathogenic Escherichia coli strains (EPEC) carrying the eae gene encoding intimin are divided into typical strains producing bundle forming pili, encoded by the bfpA gene, and atypical strains lacking the gene. In the study typical and atypical EPEC that did not agglutinated with EPEC polyvalent antisera but carrying virulence factors characteristic to other pathogenic E. coli i.e. diffusely adhering and enteroaggregative E. coli were isolated from 24 (43.6%) of 55 children > 10 years old with persistent diarrhea. These results indicated that non-typeable typical and atypical EPEC can contribute to chronic intestinal infections in teenagers.