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1.
Bull Exp Biol Med ; 176(4): 466-471, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38488964

RESUMEN

We studied the possibility of using 4-hexylresorcinol to increase the efficiency of anti-mycobacterial chemotherapy. In an in vitro experiment, 4-hexylresorcinol increased the efficiency of rifampicin, kanamycin, and isoniazid against Mycobacterium smegmatis by 3-5 times. Experiments in sanitation of BALB/c mice infected with M. smegmatis showed the best efficacy of the isoniazid and 4-hexylresorcinol combination in comparison with isoniazid monotherapy. The growth-inhibiting activity of the combination of antibiotic rifabutin with 4-hexylresorcinol was shown on 6 strains of M. tuberculosis. A 2-fold decrease in the minimum inhibitory concentration of this antibiotic in the presence of half-minimum inhibitory concentration of 4-hexylresorcinol was demonstrated for monoresistant strain M. tuberculosis 5360/42Hr. On the mouse model of experimental tuberculosis caused by M. tuberculosis H37Rv, a 5-fold decrease in lung contamination and more rapid complete cure were achieved in animals treated with the combination of rifabutin and 4-hexylresorcinol in comparison with rifabutin monotherapy.


Asunto(s)
Hexilresorcinol , Mycobacterium tuberculosis , Tuberculosis , Animales , Ratones , Antituberculosos/farmacología , Antituberculosos/uso terapéutico , Isoniazida/farmacología , Isoniazida/uso terapéutico , Hexilresorcinol/farmacología , Rifabutina/farmacología , Rifabutina/uso terapéutico , Tuberculosis/tratamiento farmacológico , Pruebas de Sensibilidad Microbiana , Adyuvantes Inmunológicos/uso terapéutico
2.
Bull Exp Biol Med ; 176(3): 342-346, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38342813

RESUMEN

Dormant forms of causative agents of healthcare-acquired infections Moraxella catarrhalis and Kocuria rhizophila have been obtained. Dormant forms cells retained viability during long-term storage (≈107 CFU/ml after 2 months) under provocative conditions (lack of nutrient sources; temperature 20°C, oxygen access) were characterized by heat resistance, and acquired special ultrastructural organization typical of dormant forms (compacted nucleoid, thickened cell wall). They were also capable of forming alternative phenotypes (dominant and small colony variants) in a new cycle of germination in a fresh medium. These results demonstrate that the dormant forms can be responsible both for survival in the environment and persistence in the host organism.


Asunto(s)
Micrococcaceae , Moraxella catarrhalis , Moraxella catarrhalis/genética , Moraxella catarrhalis/metabolismo , Fenotipo
3.
Artículo en Ruso | MEDLINE | ID: mdl-34874652

RESUMEN

OBJECTIVE: To study the efficacy and safety of sequential MexidoL therapy, administered intravenously (500 mg once a day) for 14 days, followed by taking the oral form Mexidol FORTE 250 at a dose of 250 mg (1 tablet) 3 times a day for 60 days in elderly patients with chronic cerebral ischemia (CCI) on the background of arterial hypertension and atherosclerosis. MATERIAL AND METHODS: An open prospective observational study included 60 patients with an established diagnosis (CCI), confirmed by the results of neuroimaging. All patients were examined with an assessment of neuropsychological status (MoCA test), severity of asthenia (scale MFI-20), emotional state (Hamilton anxiety and depression scale), motor functions (formalized clinical scale for assessing motor activity of elderly Tinetti). The effectiveness of the therapy was evaluated according to the quality of life questionnaire (SF-36). RESULTS: The results of the study showed the high efficiency and safety of sequential therapy with Mexidol in relation to the relief of asthenic and emotional disorders, improving the state of cognitive functions, improving the quality of life of patients. The maximum effect occurred after the end of the full course of therapy. High adherence of patients to the therapy, low frequency of adverse events are shown. CONCLUSION: Sequential use of intravenous administration of Mexidol followed by oral administration of Mexidol FORTE 250 is an effective and safe way to treat patients with CCI.


Asunto(s)
Isquemia Encefálica , Calidad de Vida , Anciano , Isquemia Encefálica/tratamiento farmacológico , Humanos , Neuroimagen , Picolinas/efectos adversos
4.
Bull Exp Biol Med ; 171(4): 458-460, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34542762

RESUMEN

High efficiency of a combined preparation including synergistic polymyxin B and 4-hexylresorcinol was shown for treatment of experimental sepsis caused by an antibiotic-resistant highly virulent hypermucoid Klebsiella pneumoniae strain KPM9Pmr in mice. Complex therapy with polymyxin B (1 mg/kg) and 4-hexylresorcinol (30 mg/kg) led to cure in 80%; in 20% of these mice, no bacterial cells were found. After treatment with polymyxin B alone, only 50% animals survived and all of them contained bacterial cells. Comparative analysis of the results of monotherapy and combined treatment indicates that 4-hexylresorcinol not only increases the efficiency of antibiotic, but also minimizes persistence of the infection agent and therefore, the risk of development of antibiotic resistance.


Asunto(s)
Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Hexilresorcinol/farmacología , Klebsiella pneumoniae/efectos de los fármacos , Sepsis/tratamiento farmacológico , Animales , Animales no Consanguíneos , Antibacterianos/farmacología , Modelos Animales de Enfermedad , Sinergismo Farmacológico , Femenino , Infecciones por Klebsiella/complicaciones , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/patología , Klebsiella pneumoniae/patogenicidad , Ratones , Pruebas de Sensibilidad Microbiana , Polimixina B/farmacología , Polimixina B/uso terapéutico , Polimixinas/análogos & derivados , Polimixinas/farmacología , Polimixinas/uso terapéutico , Sepsis/microbiología
5.
Artículo en Ruso | MEDLINE | ID: mdl-31317893

RESUMEN

AIM: To evaluate the efficacy and safety of cytoflavin as an additional agent in the treatment of painful diabetic polyneuropathy and to analyze changes in the life quality of the patients studied. MATERIAL AND METHODS: An analysis of treatment data was carried out in 61 patients with verified painful diabetic polyneuropathy, who were divided into 2 groups depending on the therapy regimen. Patients of the main group (n=36) at the start of the therapy with gabapentin additionally received cytoflavin: intravenously, slowly, 10 ml diluted in 0.9% NaCl 200 ml for 10 days, followed by switching to per os 2 tablets 2 times a day for 25 days. Patients of the comparison group used gabapentin in comparable doses as an analgesic symptomatic therapy. Clinical neurological and anamnestic methods were used to monitor and assess the condition of patients. RESULTS AND CONCLUSION: Cytoflavin inclusion in the standard symptomatic treatment of patients with painful diabetic polyneuropathy contributed to a more pronounced decrease in the subjective assessment of pain (VAS scale) by the 10th day (42.8±2.4 mm versus 58.2±2.1 mm in the comparison group) and its maximum level of decline to 21-25 days. The achieved result was maintained by the 35th day (21.4±1.1 mm against 22.4±1.7 mm in the comparison group). At the same time, the quality of life of patients as assessed by SF-36 was significantly increased after treatment. The results obtained, along with the safety of the drug, allow us to recommend its inclusion in the treatment regimens for patients with this pathology.


Asunto(s)
Neuropatías Diabéticas , Calidad de Vida , Analgésicos , Neuropatías Diabéticas/complicaciones , Neuropatías Diabéticas/terapia , Humanos , Dolor , Mejoramiento de la Calidad
6.
Mikrobiologiia ; 86(2): 217-28, 2017.
Artículo en Ruso | MEDLINE | ID: mdl-30299066

RESUMEN

The preservation of activity of extracellular enzymes in soil is presently associated with their immobilization on organic or inorganic carriers. Enzyme immobilization results, however, in a significant decrease in enzymatic activity. In the present work, the mechanism responsible for promotion of the catalytic activity was revealed, as well as the favorable effect of low-molecular alkylhydrozybenzenes of the class of alkylresorcinols, which are common in soil organic matter, on stability of immobilized enzymes (exemplified by amylases) by their post-translational modification. Optimal conditions (enzyme to sorbent ratio, pH optimum, CaCl2 concentration, and sorption time) for amylase sorption on a biological sorbent (yeast cell walls) were determined and decreased activity of the immobilized enzyme compared to its dissolved state was confirmed. Alkylresorcinols (C7AHB) at concentrations of 1.6 to 80 mM were found to cause an increase of amylase activity both in the case of already sorbed enzymes (by 30%) and in the case of a free dissolved enzyme with its subsequent immobilization (by 50­60%). In both cases, the optimal C7AHB concentration was 16 mM. Amylase stability was determined for C7AHB-modified and unmodified enzymes immobilized on the biological sorbent after two cycles of freezing (­20°C) and thawing (4°C). Inverse dependence was revealed between increasing stability of C7AHB-modified enzymes and an increase in their activity, as well as higher stability of immobilized modified amylases than of the dissolved modified enzyme. Investigation of the effect of C7HOB-modification in the preservation of activity in immobilized amylases after four freeze­thaw cycles revealed: (1) better preservation of activity by the modified immobilized enzymes compared to immobilized ones; (2) differences in the dynamics of activity loss within compared pairs, with activity of immobilized amylases decreasing after the second cycle to a lower level (42%) than activity of the modified immobilized enzymes after the fourth cycle (48%). These results demonstrate that in the preservation of activity of extracellular enzymes in soil both stabilization mechanisms are of importance: immobilization on organic carriers and modification of the enzyme conformation by low-molecular compounds with the functions of chemical chaperones.


Asunto(s)
Amilasas/química , Enzimas Inmovilizadas/química , Modelos Químicos , Suelo
7.
Ter Arkh ; 88(8): 19-24, 2016.
Artículo en Ruso | MEDLINE | ID: mdl-27636922

RESUMEN

AIM: to evaluate the efficiency of decimeter wave therapy and halotherapy, which were additionally added to basic therapy, in patients with chronic obstructive pulmonary disease (COPD) concurrent with hypertension at the inpatient stage. SUBJECTS AND METHODS: 36 patients aged 20 to 75 years with Stages I-II COPD concurrent with Stages I-II, first-second grade hypertension were examined and treated. The clinical examination included collection of complaints and medical history data, clinical laboratory and instrumental (electrocardiography, spirography) studies, and health-related quality of life (using the SF-36 questionnaire). The patients were randomized into two groups: a study group and a comparison group. The study group patients received decimeter wave therapy and halotherapy in addition to basic drug treatment; the comparison patients had basic drug therapy. RESULTS: Pre- and postoperative comparative analysis of the major clinical manifestations of comorbidities revealed more pronounced positive changes with the lower rate of clinical manifestations in the study group. It was also observed to have a more marked reduction in blood pressure (BP) with its goal levels achieved. The mean pulse BP decreased by 28% in the study group (p=0.000005) and did not statistically reduced in the comparison group. In the study group patients, the integral quality-of-life indicator after a package of medical rehabilitation measures became statistically significantly higher by 35%. This indicator in the comparison group was statistically significantly unchanged. CONCLUSION: The directionality of the proposed rehabilitation complex towards the common pathogenetic components of the development and progression of COPD and hypertension, as well as the high efficiency of the complex justify its appropriate inclusion in the combination treatment and rehabilitation of this category of patients.


Asunto(s)
Hipertensión/epidemiología , Enfermedad Pulmonar Obstructiva Crónica , Calidad de Vida , Terapia Respiratoria/métodos , Terapia por Ondas Cortas/métodos , Cloruro de Sodio/administración & dosificación , Aerosoles/administración & dosificación , Capacidad Cardiovascular/fisiología , Capacidad Cardiovascular/psicología , Comorbilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Gravedad del Paciente , Modalidades de Fisioterapia , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/psicología , Enfermedad Pulmonar Obstructiva Crónica/rehabilitación , Pruebas de Función Respiratoria/métodos , Resultado del Tratamiento
8.
Mikrobiologiia ; 85(2): 126-44, 2016.
Artículo en Ruso | MEDLINE | ID: mdl-27476201

RESUMEN

The review deals with the unique microbial group responsible for anaerobic ammonium oxidation with nitrite (anammox), and with the role of this process in development of the biotechnology for removal of nitrogen compounds from wastewater. The history of the study of this process is briefly related. Up-to date knowledge on the intracellular organization, energy metabolism, growth stoichiometry, and physiology of anammox bacteria is described, and the main methods for cultivation of these microorganisms are characterized. Special attention is paid to the problems associated with practical application of anammox bacteria, which result from their extremely slow growth, the absence of pure cultures, and the interaction with other microbial groups.


Asunto(s)
Amoníaco/metabolismo , Bacterias Anaerobias/crecimiento & desarrollo , Aguas Residuales/microbiología , Microbiología del Agua
9.
Klin Med (Mosk) ; 94(1): 39-42, 2016.
Artículo en Ruso | MEDLINE | ID: mdl-27172721

RESUMEN

The study included 1172 patients (410 men and 762 women) at the mean age of 60.3 ± 10.4 years with grade I-II (stage I-II) arterial hypertension (AH) admitted to the clinic of Institute of Experimental Medicine. The patients were divided into 2 groups based on the results of clinical and laboratory diagnostics. Group 1 (n = 525) included patients with AH and hepatobiliary system (HBS) diseases, group 2 (n = 647) patients with AH without HBS diseases. The patients group 1 had a thicker intima-media complex of carotid arteries, higher peak systolic bloodflow rate in the internal and vertebral carotid arteries, more pronounced coiling of internal carotid arteries than patients of group 2. Patients with AH and HBS diseases exhibited correlation between bloodflow rate in external carotid arteries and atherogenicity coefficient. Duplex scanning of neck vessels of in patients with AH without HBS diseases revealed peculiar changes of the intima-media thickness and hemodynamically significant changes of the blood flow in the internal carotid arteries that may be of prognostic value in this nosological syntropy and require the personified approach to diagnostics, treatment, and prevention of these conditions.


Asunto(s)
Enfermedades de las Vías Biliares , Arterias Carótidas , Hipertensión , Hepatopatías , Arteria Vertebral , Anciano , Enfermedades de las Vías Biliares/complicaciones , Enfermedades de las Vías Biliares/diagnóstico , Enfermedades de las Vías Biliares/fisiopatología , Arterias Carótidas/diagnóstico por imagen , Arterias Carótidas/fisiopatología , Grosor Intima-Media Carotídeo , Femenino , Hemodinámica , Humanos , Hipertensión/complicaciones , Hipertensión/diagnóstico , Hipertensión/fisiopatología , Hepatopatías/complicaciones , Hepatopatías/diagnóstico , Hepatopatías/fisiopatología , Masculino , Persona de Mediana Edad , Pronóstico , Estadística como Asunto , Ultrasonografía Doppler Dúplex/métodos , Arteria Vertebral/diagnóstico por imagen , Arteria Vertebral/fisiopatología
10.
Artículo en Ruso | MEDLINE | ID: mdl-27029446

RESUMEN

OBJECTIVES: Evaluation of effectiveness of Mexidol in optimization of hypolipidemic therapy in ischemic stroke and diabetes mellitus patients. MATERIAL AND METHODS: Authors analyzed the indicators of lipid status: total cholesterol, low-density lipoproteins, high density lipoproteins, triglycerides and concentration of platelet factor-4, ß-tromboglobulin, von Willebrand factor in 68 patients with acute ischemic stroke and diabetes mellitus. Authors investigate the dynamics of these parameters (1(st), 21(st), 3-d and 6(th) month after onset stroke) depending on timing and dose of Mexidol. RESULTS: Long time therapy of Mexidol may optimize of hypolipidemic therapy in ischemic stroke and diabetes mellitus patients.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Hipolipemiantes/uso terapéutico , Lípidos/sangre , Picolinas/uso terapéutico , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/tratamiento farmacológico , Plaquetas/efectos de los fármacos , Femenino , Hemostasis/efectos de los fármacos , Humanos , Hipolipemiantes/farmacología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Accidente Cerebrovascular/sangre , Resultado del Tratamiento , beta-Tromboglobulina/análisis , Factor de von Willebrand/análisis
11.
Ter Arkh ; 88(1): 40-45, 2016.
Artículo en Ruso | MEDLINE | ID: mdl-26978608

RESUMEN

AIM: To examine the incidence of polymorbidity (PM) and changes in its rates in 2003 to 2011 in cardiac and gastroenterologic patients living in the Novosibirsk Region and the Republic of Sakha (Yakutia) in accordance with gender, occupation, and residence. SUBJECTS AND METHODS: The dynamics of PM rates was analyzed in 13 496 patients who had been examined and treated at the Cardiology and Gastroenterology Departments, Therapeutic Clinic, Research Institute of Experimental and Clinical Medicine (Novosibirsk), 2003-2011. The study used an archival research method and a statistical analysis of all nosological entities, groups, and classes in ICD-10, regardless of whether the diagnosis was primary or concurrent. RESULTS: There was an increase in PM rates among the therapeutic clinic's patients of regardless of their gender and occupation. There were gender differences in the incidence of PM: its higher rates were noted in the women than those in the men among both the residents of the Novosibirsk Region and those of the Republic of Sakha (Yakutia). More significantly higher PM rates were registered in the male inhabitants of the Novosibirsk Region. There were also regional differences in the incidence of PM: its rates proved to be higher in the patients in the Republic of Sakha (Yakutia) than in those in the Novosibirsk Region in 2003-2007. At the same time, the growth rates for PM were more marked in the patients in the Novosibirsk region than in those in the Republic of Sakha (Yakutia); these differences levelled off in subsequent years. CONCLUSION: The findings indicate a pronounced increase in the incidence of PM in cardiac and gastroentorologic patients and determine a need to keep in mind the influence of gender, social, and regional factors on its development in order to create and improve a primary and secondary prevention, diagnosis and treatment system.


Asunto(s)
Enfermedades Gastrointestinales/epidemiología , Cardiopatías/epidemiología , Adolescente , Factores de Edad , Anciano de 80 o más Años , Servicio de Cardiología en Hospital/estadística & datos numéricos , Comorbilidad/tendencias , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Ocupaciones/estadística & datos numéricos , Características de la Residencia/estadística & datos numéricos , Factores Sexuales , Siberia/epidemiología , Factores Socioeconómicos
12.
Mikrobiologiia ; 84(5): 512-28, 2015.
Artículo en Ruso | MEDLINE | ID: mdl-27169240

RESUMEN

Effect of sublethal doses of physical and chemical stressors (heat shock for 2 h at 45 degrees C and addition of C12-alkylhydroxybenzene, a microbial alarmone) on development of resistance to the subsequent lethal antibiotic attack and the role of the time interval between these treatments were studied on a submerged batch culture of Escherichia coli 12. The interval sufficient for the development of stress response provides for development of temporary adaptive resistance to the antibiotic attack, resulting in increased number of surviving persister cells. The interval below the time required for the stress response potentiates cell death and results in a decreased number of persisters. Heterogeneity of the fractions (10(-4) to 10(-2)% of the intial CFU number) surviving lethal doses of an antibiotic (a mpicillin or ciprofloxacin) was found. Apart from a low number of antibiotic-resistant cells (up to 0.005% of surviving cells), the fractions contained antibiotic-tolerant forms, such as temporarily resistant metabolically adapted cells, long-term persisters, and the cells of slowly growing SCV variants with small colonies (d ≤ 1 mm). Persisters are hypothesized to act as precursors for cystlike dormant cells (CLC), in which the cell differentiation stage is completed and the processes of cell ametabolism (transition to the anabiotic state) are still incomplete.


Asunto(s)
Adaptación Fisiológica/efectos de los fármacos , Antibacterianos/farmacología , Derivados del Benceno/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Escherichia coli K12/efectos de los fármacos , Adaptación Fisiológica/fisiología , Ampicilina/farmacología , Ciprofloxacina/farmacología , Recuento de Colonia Microbiana , Farmacorresistencia Bacteriana/fisiología , Escherichia coli K12/fisiología , Escherichia coli K12/ultraestructura , Calor , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Estrés Fisiológico , Factores de Tiempo
13.
Mikrobiologiia ; 84(6): 673-9, 2015.
Artículo en Ruso | MEDLINE | ID: mdl-26964356

RESUMEN

Regulation of streptomycete growth and development by distant interactions of physical nature was shown using a vial-in-vial experimental setup, providing physical isolation of the inducer and detector cultures. Some effects of distant interaction were observed with Streptomyces netropsis proliferating submerged culture as an inducer and a surface culture of the same strain as a detector. The growth rate of the detector strain doubled. Spore germination was stimulated, as was indicated by a 30% increase in the number of colony-forming units (CRU) in the detector culture plated as a spore suspension. The phase variation spectrum also changed, with an increased share of the colonies of the morphotype predominant under the standard conditions.


Asunto(s)
Streptomyces/fisiología , Esporas Bacterianas , Streptomyces/citología
14.
Mikrobiologiia ; 84(6): 660-72, 2015.
Artículo en Ruso | MEDLINE | ID: mdl-26964355

RESUMEN

Effect of human inherent immunity factors of, a gene-encoded antibacterial peptide indolicidin (Ind) and a cytokine interleukin 1 (IL1) on formation of antibiotic-tolerant persister cells surviving in the presence of ciprofloxacin (Cpf, 100 µg/mL) and ampicillin (Amp, 100 µg/mL) in submerged bacterial cultures (Staphylococcus aureus FGA 209P, Escherichia coli K12, and Pseudomonas aeruginosa PAO1) was studied. While Ind in physiological concentrations (0.3 and 3.0 µg/mL) introduced to the lag- or exponential-phase cultures of test organisms exhibited no reliable effect on population growth, the number of persisters increased at 3.0 µg/mL. Bactericidal Ind concentrations (9 µg/mL) suppressed S. aureus growth (-0.1% of surviving cells) with subsequent recovery due to development of the more antibiotic-tolerant white variant. Treatment with Cpf after Ind addition resulted in mutual potentiation of their antimicrobial activity, with the number of S. aureus persisters 2 to 3 orders of magnitude lower than in the case of the antibiotic alone. IL1, another immunity factor, when introduced (0.1-1 ng/mL) to the exponentially growing S. aureus culture (but not to the lag phase culture) had a temporary growth-static effect, with the number of persisters surviving Cpf treatment (100 µg/mL) increasing by 1 to 2 orders of magnitude. Electron microscopy revealed significant alterations in the outer cell envelope layer of surviving S. aureus cells, which should be associated with their changed antigenic properties. Thus, the factors of human inherent immunity have a dose-dependent effect on the growth of bacterial populations. In combination with antibiotics, they exhibit synergism of antimicrobial action (indolicidin) and minimize (indolicidin) or increase (interleukin 1) the frequency of formation of persister cells responsible for survival of a population subjected to an antibiotic attack.


Asunto(s)
Ampicilina/farmacología , Ciprofloxacina/farmacología , Farmacorresistencia Bacteriana , Escherichia coli K12 , Viabilidad Microbiana , Pseudomonas aeruginosa , Staphylococcus aureus , Farmacorresistencia Bacteriana/efectos de los fármacos , Farmacorresistencia Bacteriana/inmunología , Escherichia coli K12/crecimiento & desarrollo , Escherichia coli K12/inmunología , Humanos , Viabilidad Microbiana/efectos de los fármacos , Viabilidad Microbiana/inmunología , Pseudomonas aeruginosa/crecimiento & desarrollo , Pseudomonas aeruginosa/inmunología , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/inmunología
15.
Mikrobiologiia ; 83(3): 284-94, 2014.
Artículo en Ruso | MEDLINE | ID: mdl-25844438

RESUMEN

Effect of the antibiotics kanamycin and ampicillin on growth and phase variation of the populations of four strains of lactic acid bacteria (Lactobacillus sp. M67AT, L. casei MB, Enterococcus faecium M, and E. faecium M3185) was studied. The presence of antibiotics in the medium resulted in a dose-dependent decrease in viable cell numbers and in partial or complete substitution of the dominant S variant with the minor Sm and Sb variants. The variants differed in colony morphology, as well as in some physiological, biochemical, biotechnological, and probiotic characteristics. The Sm type variants of all strains exhibited the highest resistance to antibiotics. High production of exopolysaccharides was found in Sb variants of lactobacilli and in S variants of enterococci. The highest antibacterial activity was found in Sm variants of lactobacilli, especially in Lactobacillus sp. M76AT The latter is biotechnologically the most promising strain, since all variants fermented milk yielding the products with uniformly pronounced functional and organoleptic properties. These patterns are of importance for the understanding of the mechanisms of antibiotic resistance and for selection of the variants with desired properties, as well as for quality control of the lactic acid bacteria starter cultures.


Asunto(s)
Antibacterianos/farmacología , Enterococcus faecium/efectos de los fármacos , Lactobacillus/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Farmacorresistencia Bacteriana , Enterococcus faecium/crecimiento & desarrollo , Enterococcus faecium/metabolismo , Fermentación , Microbiología de Alimentos , Ácido Láctico/metabolismo , Lactobacillus/crecimiento & desarrollo , Lactobacillus/metabolismo , Leche/microbiología , Polisacáridos Bacterianos/metabolismo , Probióticos
16.
Water Sci Technol ; 66(8): 1787-93, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22907466

RESUMEN

The effect of returning solids to the digester, after one of three thickening processes, on volatile solids reduction (VSR) and gas production was investigated. Three different thickening methods were compared: centrifugation, flotation and gravitational sedimentation. The amount and activity of retained biomass in thickened recycled sludge affected the efficiency of digestion. Semi-continuous laboratory digesters were used to study the influence of thickening processes on thermophilic sludge digestion efficiency. Centrifugation was the most effective method used and caused an increase of VSR from 43% (control) up to 70% and gas generation from 0.40 to 0.44 L g(-1) VS. Flotation and gravitational sedimentation ways of thickening appeared to be less effective if compared with centrifugation. These methods increased VSR only by up to 65 and 51%, respectively and showed no significant increase of gas production. The dewatering capacity of digested sludge, as measured by its specific resistance to filtration, was essentially better for the sludge digested in the reactors with centrifugated and settled recycle. The VS concentration of recycle (g L(-1)), as reflecting the amount of retained biomass, appeared to be one of the most important factors influencing the efficiency of sludge digestion in the recycling technology.


Asunto(s)
Reactores Biológicos/microbiología , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Anaerobiosis , Biomasa
17.
Water Sci Technol ; 65(3): 403-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22258668

RESUMEN

The process of anaerobic thermophilic digestion of municipal wastewater sludge with a recycled part of thickened digested sludge, was studied in semi-continuous laboratory digesters. This modified recycling process resulted in increased solids retention time (SRT) with the same hydraulic retention time (HRT) as compared with traditional digestion without recycling. Increased SRT without increasing of HRT resulted in the enhancement of volatile substance reduction by up to 68% in the reactor with the recycling process compared with 34% in a control conventional reactor. Biogas production was intensified from 0.3 L/g of influent volatile solids (VS) in the control reactor up to 0.35 L/g VS. In addition, the recycling process improved the dewatering properties of digested sludge.


Asunto(s)
Aguas del Alcantarillado , Eliminación de Residuos Líquidos/métodos , Anaerobiosis , Bacterias Anaerobias , Reactores Biológicos , Arquitectura y Construcción de Instituciones de Salud , Calor , Metano/química , Metano/metabolismo , Factores de Tiempo , Eliminación de Residuos Líquidos/economía , Agua/química
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