Navegando por Palavras-chave "mutations"

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    Chronic granulomatous disease in Latin American patients: Clinical spectrum and molecular genetics
    (Wiley-Blackwell, 2006-02-01) Agudelo-Florez, P.; Prando-Andrade, C. C.; Lopez, J. A.; Costa-Carvalho, B. T.; Quezada, A.; Espinosa, F. J.; Paiva, MAD; Roxo, P.; Grumach, A.; Jacob, C. A.; Carneiro-Sampaio, MMS; Newburger, P. E.; Condino-Neto, A.; Universidade de São Paulo (USP); Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); Univ Chile; Natl Inst Pediat; Rio de Janeiro State Employees Hosp; Univ Massachusetts
    Background. Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by early onset of recurrent and severe infections. the molecular defects causing CGD are heterogeneous and lead to absence, low expression, or malfunctioning of one of the phagocyte NADPH oxidase components. the aim of this study was to analyze the clinical features and to investigate the molecular genetic defects of Latin American patients with CGD.Procedures. the study included 14 patients. the diagnosis was based on a history of recurrent severe infections, impaired respiratory burst, and the demonstration of an underlying mutation by single strand conformation polymorphism (SSCP) or RT-PCR analysis, followed by genomic DNA or cDNA sequencing.Results. Seven unrelated patients were found to have the X-linked form of CGD (X-CGD). Heterogeneous mutations affected the CYBB gene: two insertions, one substitution, and four splice site defects; two of them are novel. Seven patients presented with one of the autosomal recessive forms of CGD (A47-CGD); all had the most common mutation, a Delta GT deletion in exon 2 of the NCF1 gene. Pneumonia was the most frequent clinical feature, followed by pyoderma, sinusitis, otitis, and liver abscess. Patients with X-CGD were more likely to have initial infections before age 2 years and to have inflammatory obstructive granulomas later. None of the patients had severe adverse reactions to BCG immunization.Conclusions. X-CGD patients from Latin America showed a high degree of molecular heterogeneity, including two novel Mutations. Their clinical characteristics included early onset of infections and eventual obstructive granulomas. A47-CGD represented 50% of the reported cases, a higher prevalence than reported in other series.
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    MUTATIONS IN THE QUINOLONE RESISTANCE-DETERMINING REGIONS OF GYRA AND PARC IN ENTEROBACTERIACEAE ISOLATES FROM BRAZIL
    (Soc Brasileira Microbiologia, 2012-10-01) Minarini, Luciene Andrade da Rocha [UNIFESP]; Darini, Ana Lucia C.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Mutations in the quinolone resistance-determining regions (QRDR) in chromosomal gyrA and parC genes and fluoroquinolone susceptibility profiles were investigated in quinolone-resistant Enterobacteriaceae isolated from community and hospitalized patients in the Brazilian Southeast region. A total of 112 nalidixic acid-resistant enterobacterial isolates collected from 2000 to 2005 were investigated for mutations in the topoisomerases genes gyrA and parC by amplifying and sequencing the QRDR regions. Susceptibility to fluoroquinolones was tested by the agar dilution method. Amongst the 112 enterobacterial isolates, 81 (72.3%) were resistant to ciprofloxacin and 5 (4.5%) showed reduced susceptibility. Twenty-six (23.2%) were susceptible to ciprofloxacin. Several alterations were detected in gyrA and parC genes. Escherichia coli isolates (47.7%) showed double mutations in the gyrA gene and a single one in the parC gene. Two unusual aminoacid substitutions are reported, an Asp87-Asn in a Citrobacter freundii isolate with reduced susceptibility to fluoroquinolones and a Glu84-Ala in one E. coli isolate. Only a parC gene mutation was found in fluoroquinolone-susceptible Enterobacter aerogenes. None of the isolates susceptible to ciprofloxacin presented mutations in topoisomerase genes. This comprehensive analysis of QRDRs in gyrA and parC genes, covering commonly isolated Enterobacteriaceae in Brazil is the largest reported up to now.