RESUMO
CTX-M-15, an extended-spectrum ß-lactamase emerging worldwide, hydrolyzes lactam ring of ß-lactam antibiotics, and thus causes therapeutic failure and a lack of eradication of pathogenic bacteria by third-generation ß-lactams. Therefore, the enzyme is a potential target for developing agents against pathogens isolated from patients suffering from nosocomial infections. The CTX-M-15 protein was purified and crystallized at 298 K. X-ray diffraction data from CTX-M-15 crystal have been collected to 1.46 Å resolution using synchrotron radiation. The crystal of CTX-M-15 belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 45.50, b = 44.23, and c = 116.92 Å. Analysis of the packing density shows that the asymmetric unit probably contains two molecules with a solvent content of 41.26%.
Assuntos
Infecções por Escherichia coli/enzimologia , Escherichia coli/enzimologia , beta-Lactamases/química , Cristalização , Cristalografia por Raios X , Escherichia coli/química , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Humanos , Resistência beta-Lactâmica , beta-Lactamases/isolamento & purificaçãoRESUMO
The outcome of Helicobacter pylori infection was analyzed in 114 dyspeptic patients treated with triple-drug therapy including clarithromycin. Clarithromycin resistance (in 20.2% of our isolates) was mainly caused by an A2142G mutation in the 23S rRNA gene of H. pylori. H. pylori eradication was obtained in all patients with clarithromycin-susceptible isolates but not in any patients with clarithromycin-resistant isolates (P = 0.0001). Therefore, it would be useful to conduct H. pylori antimicrobial susceptibility testing of the first gastric biopsy culture before choosing the first three drugs for therapy of infected patients.