RESUMEN
OBJECTIVE: During 2003-2005, an outbreak of meningitis due to Neisseria meningitidis serogroup C occurred in China. With the aim to find strain clues result in the final epidemics, the ancestral strain 053442, a clinical isolate, and a carrier strain 053426 with different gene type were analyzed. METHODS: Clinical strain 053442 and carrier strain 053426 were cultured on GC agar plates under the same condition. Two-dimensional electrophoresis was performed using the pH 3-10 nonlinear IPG strips of 24 cm length, and all the protein spots were identified by matrix-assisted laser desorption/ionization time of flight spectrometry. RESULTS: 502 and 380 protein spots were identified in 053426 and 053442 respectively, relating to 266 and 202 different genes covering a wide range of cellular functions. The express volume and number of proteins involved in energy metabolism, protein synthesis and amino acid biosynthesis in 053426 were higher than in 053442. Virulence factor Opa, Opc and a series of proteins involved in pilus assembly and retraction were identified in 053442, which appear to be of primary importance in colonization and invasion of human cells. Compared to 053442, virulence protein species were less in 053426, with lower express volumes too. No Opa and Opc were detected in 053426. CONCLUSIONS: The different protein expression profiles of the clinical strain 053442 and carrier strain 053426 in the present study provide some clues of the different pathogenicity of the two strains, which may account for result in the final epidemics.
Asunto(s)
Proteínas Bacterianas/análisis , Técnicas de Tipificación Bacteriana , Brotes de Enfermedades , Meningitis Meningocócica/epidemiología , Meningitis Meningocócica/microbiología , Neisseria meningitidis Serogrupo C/aislamiento & purificación , Proteoma/análisis , China/epidemiología , Electroforesis en Gel Bidimensional , Humanos , Meningitis Meningocócica/líquido cefalorraquídeo , Neisseria meningitidis Serogrupo C/clasificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
In this study, 68 group A streptococcus (GAS) isolates associated with two outbreaks of acute glomerulonephritis (AGN) in China were analyzed by emm typing. A total of 11 different emm types were identified. Analysis of emm type distribution suggested that AGN outbreaks in two counties were caused by emm60.1- and emm63.0-type GAS. These two types were further characterized by pulsed-field gel electrophoresis, multilocus sequence typing, sof sequence typing, and PCR-based identification of streptococcal pyrogenic exotoxin A, B, and C (speA, speB, and speC) genes. In antimicrobial susceptibility tests, all outbreak strains were resistant to erythromycin and tetracycline, and the rates of resistance of nonoutbreak strains to the two antibiotics were 63.6% and 90.9%. This study is also the first to report a nephritogenic M63 GAS strain.
Asunto(s)
Brotes de Enfermedades , Glomerulonefritis/epidemiología , Glomerulonefritis/microbiología , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/clasificación , Streptococcus pyogenes/genética , Adolescente , Animales , Antibacterianos/farmacología , Antígenos Bacterianos/genética , Proteínas de la Membrana Bacteriana Externa/genética , Toxinas Bacterianas/genética , Técnicas de Tipificación Bacteriana , Proteínas Portadoras/genética , Niño , Preescolar , China/epidemiología , Análisis por Conglomerados , Dermatoglifia del ADN , ADN Bacteriano/química , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Streptococcus pyogenes/aislamiento & purificaciónRESUMEN
OBJECTIVE: To investigate the differences between the sequences of papA and papG of UPEC4030 strain and the related genes, to better understand the genetic variation of UPEC4030 papA and its combination forms with papG so as to identify if it was a new genotype. METHODS: Cloning and sequencing methods were used to analyze the sequences of papG and papA of UPEC4030 strain and to compare their related sequences. RESULTS: Through sequence analysis of papA, it was revealed that there was a 722 bp gene, encoding 192 amino acid polypeptide. The overall homology of the papA genes between UPEC4030 and the standard strains of ten F types were 36.11% - 77.95% and 22.20% - 78.34% at nucleotide and deduced amino acid levels. Homology between the sequences of reverse primers and the corresponding sequence of UPEC4030 papA was 10.00% - 66.67%. The results confirmed that UPEC4030 strain contained a novel papA variant. Through sequence analysis of UPEC4030 papG, we revealed a 1100 bp gene, encoding 337 amino acid polypeptide. The homology of the papG genes between UPEC4030 and UPEC IA2, the standard strain, was 99.00% at nucleotide level and 99.11% at deduced amino acid and UPEC4030 strain carried class II genotype of papG. CONCLUSION: UPEC4030 strain contained an unknown papA variant or the new genotype and carried class II genotype of papG. The pathogenic mechanism and epidemiology call for further study.