RESUMEN
Main scientific-research studies regarding protein bacterial toxins of the most widespread bacteria that belong to Staphylococcus spp. genus and in particular the most pathogenic species for humans--Staphylococcus aureus, are analyzed. Structural and biological properties of protein toxins that have received the name of staphylococcus pyrogenic toxins (PTSAg) are presented. Data regarding genetic regulation of secretion and synthesis of these toxins and 3 main regulatory genetic systems (agr--accessory gene regulator, xpr--extracellular protein regulator, sar--staphylococcal accessory regulator) that coordinate synthesis of the most important protein toxins and enzymes for virulence of S. aureus, are presented.
Asunto(s)
Toxinas Bacterianas/inmunología , Regulación Bacteriana de la Expresión Génica/inmunología , Infecciones Estafilocócicas/inmunología , Staphylococcus aureus/inmunología , Linfocitos T/inmunología , Proteínas Bacterianas/genética , Proteínas Bacterianas/inmunología , Toxinas Bacterianas/biosíntesis , Toxinas Bacterianas/clasificación , Toxinas Bacterianas/genética , Anergia Clonal , Transferencia de Gen Horizontal , Interacciones Huésped-Patógeno , Humanos , Activación de Linfocitos , Proteínas de Unión al GTP Monoméricas/genética , Proteínas de Unión al GTP Monoméricas/inmunología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/patología , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidad , Superantígenos/genética , Superantígenos/inmunología , Linfocitos T/microbiología , Linfocitos T/patología , Transactivadores/genética , Transactivadores/inmunología , VirulenciaRESUMEN
OBJECTIVE: to study the heterogeneity of internal fragments of the aur gene coding a proteolytic enzyme aureolysin in strains of Staphylococcus aureus with different enzymatic activity, which were allocated with the affected skin of patients with atopic dermatitis. MATERIALS AND METHODS: the study included 125 patients aged 1 to 35 years old with the diagnosis of atopic dermatitis. 100 clinical strains of Staphylococcus aureus were studied in monoculture. Identification of the strains of Staphylococcus aureus in skin was performed using standard classical methods. Specific biochemical microtests using a set of APIs Staph 20 (bioMerieux SA, France) were conducted to confirm the obtained results. Reference strains of S. aureus ATCC 29213, NCTC at 8.325 were used. Specific aur gene loci were detected by the method of multiplex polymerase chain reaction. Proteolytic activity was determined by the ability to split the substrate (human IgG, Sigma) into fragments using as inhibitors of matrix 0.01-0.1M solutions of sodium EDTA. The sequencing of the amplified areas of aur gene, including the preliminary stages of separation and purification of DNA, was performed by Syntol, Moscow. RESULTS: different strains of the conservative plot amplicon fragment of aur contains up to 9 polymorphic nucleotides. The index of the nucleotide diversity for proteolytic active strains was less (Pi = 0.04) than for proteolytically inactive (Pi = 0.07), p < 0.05. It should be noted that all proteolytically active strains were isolated from the skin of patients with high and moderate severity of atopic dermatitis (67.8 +/- 5.4 points on SCORAD scale) with erythematous form of the disease. The inactive strains were allocated in patients of older age with reduced severity of atopic dermatitis (with the dry form of skin lesions).
Asunto(s)
Proteínas Bacterianas/genética , Dermatitis Atópica/microbiología , Metaloendopeptidasas/genética , Polimorfismo de Nucleótido Simple , Piel/microbiología , Staphylococcus aureus/genética , Adolescente , Adulto , Secuencia de Aminoácidos , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Datos de Secuencia Molecular , Staphylococcus aureus/aislamiento & purificaciónRESUMEN
We studied contractile responses of isolated smooth muscles from human uterus induced by P2 receptor agonists. In preparations from pregnant uterus all tested P2 receptor agonists caused smooth muscle contractions. The relative activity of P2 receptor agonists decreased in the following order: a,b-methylene-ATP-uridine triphosphate-ATP. Responses induced by ATP and ADP were similar. The amplitude of contractions induced by alpha,beta-methylene-ATP significantly decreased in the presence of P2 receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid. None of tested P2 receptor agonists induced contractions of isolated myometrium from nonpregnant women. Our results indicate that pregnant human uterus contains P2 receptors mediating the contractile response.
