RESUMO
INTRODUCTION: The objective of this study was to assess the performance of a technique (S. PneumoStrip test) based on PCR followed by reverse strip hybridisation for the detection of Streptococcus pneumoniae serotypes directly in blood culture vials. METHODS: One hundred and ten (110) pairs of isolated strains and their corresponding original blood cultures vials were studied in parallel. Pure isolated strains were conventionally serotyped using latex agglutination and the Quellung reaction. The S. PneumoStrip test was carried out directly in the original blood culture samples. RESULTS: In 102 cases (92.7%), results of the serotype obtained by Quellung coincided with their corresponding original blood cultures typed by S. PneumoStrip. CONCLUSIONS: S. PneumoStrip test is a good alternative technique for direct pneumococcal serotyping in blood culture clinical samples.
Assuntos
Infecções Pneumocócicas , Streptococcus pneumoniae , Hemocultura , Humanos , Infecções Pneumocócicas/microbiologia , Reação em Cadeia da Polimerase , Sorogrupo , Sorotipagem , Streptococcus pneumoniae/classificaçãoRESUMO
The aim of this work was to study the in vitro digestion of Cry1A(b) protein by pepsin. To perform this work, a protein fraction purified from transgenic maize by immunoadsorption was employed. The undigested fraction showed several bands of molecular weight ranging between 14 and 70 kDa when assayed by SDS-PAGE. These bands were identified as corresponding to Cry1A(b) protein by immunochemical techniques and mass spectrometry. The rate of degradation of the purified fraction by pepsin estimated by ELISA was found to be about 75% within 30 min, and the protein concentration remained constant up to 4 h. In all treated samples, the full-length protein and fragments present in Cry1A(b) fraction were absent and peptides of less than 8.5 kDa were mainly found by SDS-PAGE and mass spectrometry. These peptides did not react with antiserum against Cry1A(b) protein by Western blotting. These results suggest that Cry1A(b) fraction purified from transgenic maize is rapidly and extensively degraded by pepsin, giving peptides of low molecular mass.
Assuntos
Proteínas de Bactérias/metabolismo , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Pepsina A/metabolismo , Plantas Geneticamente Modificadas/genética , Zea mays/metabolismo , Ração Animal , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Western Blotting , Digestão , Eletroforese em Gel de Poliacrilamida , Endotoxinas/genética , Endotoxinas/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Mucosa Gástrica/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/isolamento & purificação , Pepsina A/genética , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Coelhos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Suínos , Zea mays/genéticaRESUMO
Clostridium tyrobutyricum is the main agent responsible for "late blowing" in cheese, which causes severe economic losses. Nowadays, the reference method for its detection is the Most-Probable-Number (MPN); however, it is time consuming and non-specific. Thus, in order to check milk contamination with spores of C. tyrobutyricum, a more specific and rapid method would be required. The objective of this work was to obtain a ligand to establish the basis to develop a biomagnetic separation method for detection of C. tyrobutyricum spores. This study describes the selection of thirteen highly affine peptides to C. tyrobutyricum spores from a phage-display peptide library. In order to test the ability of the peptides attached to a solid support to bind the spores, the most frequent peptide was synthesised and used to coat paramagnetic beads.
