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1.
BMC Gastroenterol ; 23(1): 71, 2023 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-36907848

RESUMEN

BACKGROUND: Various environmental risk factors have been associated with the pathogenesis of inflammatory bowel disease. In this study we aimed to identify lifestyle factors that affect the onset of Crohn's disease and ulcerative colitis. METHODS: 2294 patients from the Swiss IBD Cohort Study received a questionnaire regarding physical activity, nutritional habits and status of weight. In addition, a control group was formed comprising patients' childhood friends, who grew up in a similar environment. RESULTS: Overall, 1111 questionnaires were returned (response rate: 48.4%). Significantly more patients with inflammatory bowel disease reported no regular practice of sport during childhood and beginning of adulthood compared to the control group (p = 0.0001). No association between intake of refined sugar and onset of inflammatory bowel disease was observed. More patients with Crohn's disease compared to ulcerative colitis and controls suffered from overweight during childhood (12.8% vs. 7.7% and 9.7%, respectively; p = 0.027). CONCLUSIONS: Our study underlines the relevance of environmental factors in the development of inflammatory bowel disease. Our results imply a protective effect of physical activity regarding the onset of inflammatory bowel disease.


Asunto(s)
Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Humanos , Adulto , Colitis Ulcerosa/complicaciones , Estudios de Cohortes , Suiza , Enfermedades Inflamatorias del Intestino/complicaciones , Estilo de Vida
2.
Biomed Eng (NY) ; 56(5): 327-331, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36686583

RESUMEN

A brief overview of the main areas of research presented in the section "Ecology and human health" at the XV International Scientific Conference "Physics and Radioelectronics in Medicine and Ecology - PhREME'2022," held on June 28-30, 2022 in Suzdal', is presented.

4.
J Arthroplasty ; 37(7): 1296-1301, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35307526

RESUMEN

BACKGROUND: The clinical examination for laxity has been considered a mainstay in evaluation of the painful knee arthroplasty, especially for the diagnosis of instability. More than 10 mm of anterior-posterior (AP) translation in flexion has been described as important in the diagnosis of flexion instability. The inter-observer reliability of varus/valgus and AP laxity testing has not been tested. METHODS: Ten subjects with prior to total knee arthroplasty (TKA) were examined by 4 fellowship-trained orthopedic knee arthroplasty surgeons. Each surgeon evaluated each subject in random order and was blinded to the results of the other surgeons. Each surgeon performed an anterior drawer test at 30 and 90 degrees of flexion and graded the instability as 0-5 mm, 5-10 mm or >10 mm. Varus-valgus testing was also graded. Motion capture was used during the examination to determine the joint position and estimate joint reaction force during the examination. RESULTS: Inter-rater reliability (IRR) was poor at 30 and 90 degrees for both the subjective rater score and the measured AP laxity in flexion (k = 018-0.22). Varus-valgus testing similarly had poor reliability. Force applied by the rater also had poor IRR. CONCLUSION: Clinical testing of knee laxity after TKA has poor reliability between surgeons using motion analysis. It is unclear if this is from differences in examiner technique or from differences in pain or quadriceps function of the subjects. Instability after TKA should not be diagnosed strictly by clinical testing and should involve a complete clinical assessment of the patient.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Inestabilidad de la Articulación , Artroplastia de Reemplazo de Rodilla/efectos adversos , Artroplastia de Reemplazo de Rodilla/métodos , Fenómenos Biomecánicos , Humanos , Inestabilidad de la Articulación/cirugía , Articulación de la Rodilla/cirugía , Dolor/cirugía , Rango del Movimiento Articular , Reproducibilidad de los Resultados
5.
Dis Colon Rectum ; 65(3): 373-381, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34784314

RESUMEN

BACKGROUND: The vertical rectus abdominis flap is considered the gold standard in perineal reconstruction after oncological abdominoperineal resection; however, it has a nonnegligible donor site morbidity. The anterolateral thigh flap offers reliable soft tissue coverage. OBJECTIVE: The aim was to analyze long-term outcomes of composite anterolateral thigh-vastus lateralis flaps in oncological abdominoperineal resections. DESIGN: We conducted a retrospective cohort analysis of a prospectively maintained database. SETTINGS: This study was conducted in the Lausanne University Hospital. Annually, approximately 10 oncological abdomioperineal resections are performed. Literature reports 7% to 20% of patients undergoing abdominoperineal resection require flap reconstruction; in our institution, approximately 2 patients with large defects after abdominoperineal resections required reconstruction. PATIENTS: Twenty-nine pedicled anterolateral thigh-vastus lateralis flaps in 27 consecutive patients (mean age 63 years +/-11.2, 23 with radiochemotherapy) after abdominoperineal resection to cover large defects (median 190 cm2, 48-600 cm2) were analyzed. INTERVENTION: Pedicled composite anterolateral thigh-vastus lateralis flaps were performed after oncological abdominoperineal resection. MAIN OUTCOME MEASURES: Descriptive statistical analysis was conducted. Short- and long-term outcomes were analyzed, univariate and multivariate analyses were performed. Median follow-up was 16 months (12-48 months). RESULTS: Flap-related postoperative complications occurred in 16 flaps; flap-survival was 100%. Multivariate logistic analysis identified initial defect size as predictive for complications. Patients with larger defects (≥ 190 cm2) had higher complication rates (p = 0.006). Long-term analysis revealed 3 chronic fistulae, 2 tumor recurrences, 1 flap dysesthesia, and one perineal acne inversa. LIMITATIONS: Limitations include retrospective analysis, selection bias, and lacking a control group. Sample size limits statistical power. CONCLUSIONS: The pedicled anterolateral thigh-vastus lateralis flap offers reliable, stable tissue with low morbidity and good long-term outcomes. Complications compared favorably with current literature describing perineal reconstructions with rectus abdominis flaps. The composite anterolateral thigh flap is a valid alternative without the setback of abdominal donor site morbidity. See Video Abstract at http://links.lww.com/DCR/B757.RESULTADOS DEL COLGAJO COMPUESTO ANTEROLATERAL DE MUSLO PARA LA RECONSTRUCCIÓN PERINEAL DESPUÉS DE LA RESECCIÓN ABDOMINOPERINEAL POST ONCOLÓGICAANTECEDENTES:El colgajo vertical de recto abdominal se considera el estándar de oro en la reconstrucción perineal después de la resección abdominoperineal oncológica, sin embargo, tiene una morbilidad no despreciable en el sitio donante. El colgajo anterolateral del muslo ofrece una cobertura confiable de los tejidos blandos.OBJETIVO:El objetivo fue analizar los resultados a largo plazo de los colgajos compuestos anterolaterales del muslo - vasto lateral - en resecciones abdominoperineales oncológicas.DISEÑO:Realizamos un análisis, retrospectivo, de tipo cohorte, de una base de datos mantenida prospectivamente.AJUSTES:Este estudio fue realizado en el hospital universitario de Lausanne. Anualmente se realizan aproximadamente 10 resecciones abdominoperineales oncológicas. La literatura reporta que entre el 7 y el 20% de los pacientes que se someten a una resección abdominoperineal requieren de reconstrucción con colgajo; en nuestra institución, aproximadamente 2 pacientes con grandes defectos tras la resección abdominoperineal requirieron reconstrucción.PACIENTES:Fueron analizados veintinueve colgajos pediculados anterolaterales de muslo - vasto lateral - en 27 pacientes consecutivos (edad media 63 años +/- 11,2, 23 con radio quimioterapia) después de la resección abdominoperineal para cubrir defectos grandes (mediana 190 cm2, 48-600 cm2).INTERVENCIÓN:Tras la resección abdominoperineal oncológica se realizaron colgajos pediculados compuestos anterolaterales de muslo - vasto lateral.PRINCIPALES MEDIDAS DE RESULTADO:Fue realizado un análisis estadístico descriptivo. Fueron analizados los resultados a corto y largo plazo - fueron realizados así mismo análisis uni y multivariados. La mediana de seguimiento fue de 16 meses (12-48 meses).RESULTADOS:Complicaciones postoperatorias relacionadas con el colgajo ocurrieron en 16 colgajos, la supervivencia del colgajo fue del 100%. El análisis logístico multivariado identificó al tamaño del defecto inicial como predictor de complicaciones. Aquellos pacientes con defectos más grandes (≥190 cm2) tuvieron mayores tasas de complicaciones (p = 0,006). El análisis a largo plazo reveló tres fístulas crónicas, dos recidivas tumorales, una disestesia de colgajo y un acné perineal inverso.LIMITACIONES:Las limitaciones incluyen análisis retrospectivo, sesgo de selección y falta de grupo de control. El tamaño de la muestra limita el poder estadístico.CONCLUSIONES:El colgajo pediculado anterolateral de muslo - vasto lateral - ofrece tejido confiable y estable con baja morbilidad y buenos resultados a largo plazo. Los resultados de las complicaciones se mostraron favorables con respecto a la literatura actual que describe reconstrucciones perineales con colgajos de recto abdominal. El colgajo compuesto anterolateral de muslo es una alternativa válida sin el revés de la morbilidad del sitio donante abdominal. Consulte Video Resumen en http://links.lww.com/DCR/B757. (Traducción-Dr. Osvaldo Gauto).


Asunto(s)
Perineo , Procedimientos de Cirugía Plástica , Complicaciones Posoperatorias , Proctectomía/efectos adversos , Neoplasias del Recto/cirugía , Traumatismos de los Tejidos Blandos , Colgajos Quirúrgicos/efectos adversos , Muslo , Femenino , Supervivencia de Injerto , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud/métodos , Perineo/patología , Perineo/cirugía , Cuidados Posoperatorios/métodos , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Proctectomía/métodos , Procedimientos de Cirugía Plástica/efectos adversos , Procedimientos de Cirugía Plástica/métodos , Traumatismos de los Tejidos Blandos/etiología , Traumatismos de los Tejidos Blandos/cirugía , Cicatrización de Heridas
6.
Nat Commun ; 12(1): 6157, 2021 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-34697316

RESUMEN

The pathogen Staphylococcus aureus can readily develop antibiotic resistance and evade the human immune system, which is associated with reduced levels of neutrophil recruitment. Here, we present a class of antibacterial peptides with potential to act both as antibiotics and as neutrophil chemoattractants. The compounds, which we term 'antibiotic-chemoattractants', consist of a formylated peptide (known to act as chemoattractant for neutrophil recruitment) that is covalently linked to the antibiotic vancomycin (known to bind to the bacterial cell wall). We use a combination of in vitro assays, cellular assays, infection-on-a-chip and in vivo mouse models to show that the compounds improve the recruitment, engulfment and killing of S. aureus by neutrophils. Furthermore, optimizing the formyl peptide sequence can enhance neutrophil activity through differential activation of formyl peptide receptors. Thus, we propose antibiotic-chemoattractants as an alternate approach for antibiotic development.


Asunto(s)
Antibacterianos/farmacología , Factores Quimiotácticos/farmacología , Neutrófilos/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Antibacterianos/química , Antibacterianos/uso terapéutico , Carga Bacteriana/efectos de los fármacos , Factores Quimiotácticos/química , Factores Quimiotácticos/uso terapéutico , Farmacorresistencia Bacteriana/efectos de los fármacos , Inmunoterapia , Ratones , Neutrófilos/inmunología , Neutrófilos/metabolismo , Péptidos/química , Péptidos/farmacología , Fagocitosis/efectos de los fármacos , Receptores de Formil Péptido/metabolismo , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/terapia , Vancomicina/química , Vancomicina/farmacología
7.
Biomed Eng (NY) ; 55(1): 65-68, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34075254

RESUMEN

We present here a brief review of the lines of research presented at the section Ecology and Human Health of the XIVth Conference on Physics and Radio Electronics in Medicine and Ecology (PhREME'2020), July 1-3, 2020, held in Vladimir City.

8.
Dokl Biochem Biophys ; 498(1): 165-169, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34189643

RESUMEN

The effects of septoplasty and sinus lifting simulation in rats on changes in the frequency domain of heart rate variability were compared. In the early postoperative period, the low-frequency component increases, and the high-frequency component decreases. The VLF range also increased. This indicates an increase in the activity of the sympathetic nervous system and a shift in metabolism under the influence of post-surgical inflammation.


Asunto(s)
Frecuencia Cardíaca/fisiología , Inflamación/fisiopatología , Tabique Nasal/cirugía , Animales , Masculino , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Ratas , Ratas Wistar , Elevación del Piso del Seno Maxilar , Sistema Nervioso Simpático/fisiopatología
9.
Inflamm Intest Dis ; 5(4): 170-179, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33313069

RESUMEN

INTRODUCTION: The pathophysiology of inflammatory bowel disease (IBD) is incompletely understood. Current concepts imply that environmental factors (EFs) trigger disease onset as well as flares in genetically susceptible individuals. OBJECTIVE: The objective of this study is to analyze the association between IBD and various EFs, which may influence the pathogenesis of the disease. METHODS: 2,294 patients from the Swiss IBD Cohort Study (SIBDCS) received a questionnaire regarding EF including mode of delivery, breastfeeding, animals in household, and place of residence. The control group comprised patients' childhood friends, who grew up in a similar environment ("friends cohort"). RESULTS: A total of 1,111 questionnaires were returned from SIBDCS patients (response rate: 48.4%). Breastfeeding for <6 months was associated with a decreased risk for ulcerative colitis/indeterminate colitis (UC/IC) (OR: 0.473, p = 0.006). IBD patients reported less pet animals in the household than the control group (p = 0.004). The presence of cats or dogs (OR: 0.688, p = 0.015) and pet rodents (OR: 0.598, p = 0.001) in the household before the age of 20 was inversely associated with the risk for UC/IC. CONCLUSION: The present study underlines the importance of EFs in the pathogenesis of IBD. Overall, the development of UC/IC seems to be more affected from environmental influences than from Crohn's disease. Our results imply a protective effect of possessing pet animals in household and short breastfeeding regarding the onset of UC/IC.

11.
Gait Posture ; 73: 233-238, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31376749

RESUMEN

BACKGROUND: Orthopaedic walking boots are commonly prescribed following injury and surgery. The boot creates a leg length discrepancy which is thought to affect limb symmetry and gait mechanics. This study aimed to examine the effects of a corrective heel lift for the contralateral limb on the mechanics and symmetry of walking with an orthopaedic walking boot. RESEARCH QUESTION: Does a corrective heel lift reduce biomechanical alterations and asymmetries caused by an orthopaedic boot during gait? METHODS: Healthy males (n=17) walked with normal shoes (Shod), an orthopaedic boot (Boot), and a corrective heel lift on the contralateral limb to the boot (Lift). A 10-camera motion capture system (Vicon, 100Hz) and four force platforms (AMTI, 1000 Hz) recorded lower extremity biomechanics. Pairwise statistics tested for differences in hip and knee kinematics and kinetics, and a symmetry index quantified limb symmetry. FINDINGS: The Boot affected the sagittal and frontal plane hip mechanics and transverse plane knee mechanics (p<0.05), and increased the asymmetry compared to the Shod condition. The Lift improved the symmetry of some measures but increased the frontal plane hip asymmetry compared to the Boot. However, introducing the Lift did not change all kinematic variables affected by the boot. SIGNIFICANCE: The Lift reduced some of the asymmetries introduced by the Boot, but also introduced new asymmetry in the hip frontal plane motion. The leg length discrepancy caused by the boot is probably not the only cause of altered gait mechanics. Prescribing a heel lift to a patient with an orthopaedic walking boot should be based on the individual patient's needs.


Asunto(s)
Fijadores Externos , Ortesis del Pié , Marcha/fisiología , Adulto , Fenómenos Biomecánicos , Análisis de la Marcha , Voluntarios Sanos , Talón , Humanos , Rodilla , Articulación de la Rodilla , Extremidad Inferior , Masculino , Zapatos , Adulto Joven
13.
Bull Exp Biol Med ; 165(4): 449-452, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30120664

RESUMEN

We studied the effect of collagen fragments (PGP and AcPGP) on serum content of epinephrine, corticosterone, and IL-1ß in rats subjected to water-immersion stress. The degree of local inflammation accompanying ulceration was assessed by IL-1ß production by ln. gastricus caudalis cells. In 1 h, the sharp increase in hormone concentrations in the blood of stressed animals reflected the high stress intensity. Intranasal administration of PGP reduced the area of stress-induced ulcers by 63%, prevented the increase in the levels of stress hormones and the main proinflammatory cytokine in rat blood. The concentrations of IL-1ß in cell culture from regional lymph node of experimental animals returned to normal in 24 and 48 h after the stress. Acetylation of PGP prevents with gastroprotection, but does not abrogate other properties of the peptide.


Asunto(s)
Colágeno/metabolismo , Sistema Inmunológico/metabolismo , Sistemas Neurosecretores/metabolismo , Úlcera Gástrica/metabolismo , Animales , Corticosterona/metabolismo , Hidrólisis , Interleucina-1beta/metabolismo , Ratas , Ratas Wistar , Estrés Fisiológico/fisiología
14.
Ultrason Sonochem ; 44: 390-397, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29680625

RESUMEN

The size control of materials is of great importance in research and technology because materials of different size and shape have different properties and applications. This paper focuses on the synthesis of hydroxyapatite in ultrasound fields of different frequencies and intensities with the aim to find the conditions which allow control of the particles size. The results are evaluated by X-ray diffraction, Transmission Electron Microscopy, morphological and sedimentation analyses. It is shown that the hydroxyapatite particles synthesized at low intensity non-cavitation regime of ultrasound have smaller size than those prepared at high intensity cavitation regime. The explanation of observed results is based on the idea of formation of vortices at the interface between phosphoric acid and calcium hydroxide solution where the nucleation of hydroxyapatite particles is taken place. Smaller vortices formed at high frequency non-cavitation ultrasound regime provide smaller nucleation sites and smaller resulting particles, compared to vortices and particles obtained without ultrasound. Discovered method has a potential of industrial application of ultrasound for the controlled synthesis of nanoparticles.

15.
J Anim Sci ; 93(5): 2134-43, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26020309

RESUMEN

Although most pigs recover rapidly from stresses associated with the transition of weaning, a portion of the population lags behind their contemporaries in growth performance. The underlying biological and molecular mechanisms involved in postweaning differences in growth performance are poorly understood. The objective of this experiment was to use transcriptional profiling of skeletal muscle and adipose tissue to develop a better understanding of the metabolic basis for poor weaned-pig transition. A total of 1,054 pigs was reared in commercial conditions and weighed at birth, weaning, and 3 wk postweaning. Transition ADG (tADG) was calculated as the ADG for the 3-wk period postweaning. Nine pigs from both the lowest 10th percentile (low tADG) and the 60th to 70th percentile (high tADG) were harvested at 3 wk postweaning. Differential expression analysis was conducted in longissimus dorsi muscle (LM) and subcutaneous adipose tissue using RNA-Seq methodology. In LM, 768 transcripts were differentially expressed (DE), 327 with higher expression in low tADG and 441 with higher expression in high tADG pigs (q < 0.10). Expression patterns measured in LM by RNA-Seq were verified in 30 of 32 transcripts using quantitative PCR. No DE transcripts were identified in adipose tissue. To identify biological functions potentially underlying the effects of tADG on skeletal muscle metabolism and physiology, functional annotation analysis of the DE transcripts was conducted using DAVID and Pathway Studio analytic tools. The group of DE genes with lower expression in LM of low tADG pigs was enriched in genes with functions related to muscle contraction, glucose metabolism, cytoskeleton organization, muscle development, and response to hormone stimulus (enrichment score > 1.3). The list of DE genes with higher expression in low tADG LM was enriched in genes with functions related to protein catabolism (enrichment score > 1.3). Analysis of known gene-gene interactions identified possible regulators of these differences in gene expression in LM of high and low tADG pigs; these include forkhead box O1 (FOXO1), growth hormone (GH1), and the glucocorticoid receptor (NR3C1). Differences in gene expression between poor transitioning pigs and their contemporaries indicate a shift to decreased protein synthesis, increased protein degradation, and reduced glucose metabolism in the LM of low tADG pigs.


Asunto(s)
Perfilación de la Expresión Génica/veterinaria , Regulación del Desarrollo de la Expresión Génica/fisiología , Grasa Subcutánea/metabolismo , Músculos Superficiales de la Espalda/metabolismo , Sus scrofa/crecimiento & desarrollo , Animales , Secuencia de Bases , Hormona del Crecimiento/metabolismo , Datos de Secuencia Molecular , Análisis de Secuencia de ARN/veterinaria , Porcinos , Destete , Aumento de Peso/fisiología
16.
Biofizika ; 54(6): 1045-50, 2009.
Artículo en Ruso | MEDLINE | ID: mdl-20067185

RESUMEN

The mechanism of interaction of nanocrystals of hydroxyapatite with Staphylococcus aureus bacteria has been investigated. It was shown that the growth of bacteria and their colonies both in the presence and absence of hydroxyapatite nanocrystals can be described using the Fokker-Planck equation. It was found that hydroxyapatite nanocrystals adhere in a particular orientation on the surface of bacteria, decreasing substantially their colony-forming ability.


Asunto(s)
Antiinfecciosos Locales/farmacología , Hidroxiapatitas/farmacología , Staphylococcus aureus/efectos de los fármacos , Antiinfecciosos Locales/química , Fenómenos Químicos , Cristalización , Hidroxiapatitas/química , Nanoestructuras , Staphylococcus aureus/crecimiento & desarrollo , Suspensiones
19.
Antimicrob Agents Chemother ; 44(6): 1701-4, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10817733

RESUMEN

A mutant of Mycobacterium smegmatis has been isolated that is simultaneously resistant to both D-cycloserine (D-CS) and vancomycin. Genetic complementation with a PBP4 homolog restores sensitivity to both drugs. Resistance to D-CS and vancomycin in this mutant is most likely due to a novel mechanism involving peptidoglycan assembly at the cell surface.


Asunto(s)
Cicloserina/farmacología , Mycobacterium smegmatis/genética , Resistencia a la Vancomicina , Vancomicina/farmacología , Secuencia de Aminoácidos , Farmacorresistencia Microbiana , Datos de Secuencia Molecular , Mutación , Mycobacterium smegmatis/efectos de los fármacos , Alineación de Secuencia
20.
J Antimicrob Chemother ; 41(3): 341-7, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9578160

RESUMEN

The rapid spread of multidrug-resistant bacterial pathogens necessitates the search for alternative antibacterial agents. We examined the efficacy of the antibiotic nisin against 56 multidrug-resistant isolates of Streptococcus pneumoniae, 33 Staphylococcus aureus and 29 vancomycin-resistant Enterococcus faecium and Enterococcus faecalis isolates. The test strains represented a large variety of clonal types (as determined by a combination of DNA fingerprints) isolated from a variety of geographic sources, and included some of the major internationally-spread multiresistant epidemic clones of S. pneumoniae and methicillin-resistant S. aureus (MRSA), MRSA strains resistant to over 16 generically distinct antibacterial agents, and enterococcal strains resistant to all currently available chemotherapeutic agents including glycopeptides. In the overwhelming majority of cases, treatment of growing cultures with nisin at 1 mg/L (S. pneumoniae) or 10-20 mg/L (in MRSA and enterococci) caused extensive (10(3)- to 10(4)-fold) loss of viable titre accompanied by various degrees of loss in the optical density of the cultures, which was most extensive in pneumococci (>90%) and least extensive (40-50%) in enterococci. Nevertheless, extensive variation in rates of nisin-induced autolysis was observed in each bacterial species. Serial exposure of a penicillin-susceptible strain of S. pneumoniae to nisin (1 mg/L) in liquid culture resulted in the rapid appearance of stable nisin-resistant mutants in which the MIC increased from 0.4 to 6.4 mg/L and the resistance trait was transferable by genetic transformation.


Asunto(s)
Antibacterianos/farmacología , Resistencia a Múltiples Medicamentos , Bacterias Grampositivas/efectos de los fármacos , Nisina/farmacología , Antibacterianos/administración & dosificación , Coagulasa/análisis , ADN Bacteriano/genética , ADN Recombinante/genética , Relación Dosis-Respuesta a Droga , Farmacorresistencia Microbiana/genética , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/aislamiento & purificación , Enterococcus faecium/efectos de los fármacos , Enterococcus faecium/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Resistencia a la Meticilina , Pruebas de Sensibilidad Microbiana , Mutación/genética , Nisina/administración & dosificación , Nisina/genética , Resistencia a las Penicilinas , Especificidad de la Especie , Staphylococcus/efectos de los fármacos , Staphylococcus/enzimología , Staphylococcus/aislamiento & purificación , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/aislamiento & purificación , Transformación Bacteriana/genética , Vancomicina/administración & dosificación , Vancomicina/farmacología
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