Performance of indirect immunofluorescence assay, immunochromatography assay and reverse transcription-polymerase chain reaction for detecting human respiratory syncytial virus in nasopharyngeal aspirate samples

Comparison of the use of indirect immunofluorescence assay (IFA), immunochromatography assay (ICA-BD) and reverse transcription-polymerase chain reaction (RT-PCR) for detecting human respiratory syncytial virus (HRSV) in 306 nasopharyngeal aspirates samples (NPA) was performed in order to assess their analytical performance. By comparing the results obtained using ICA-BD with those using IFA, we found relative indices of 85.0 percent for sensitivity and 91.2 percent for specificity, and the positive (PPV) and negative (NPV) predictive values were 85.0 percent and 91.2 percent, respectively. The relative indices for sensitivity and specificity as well as the PPV and NPV for RT-PCR were 98.0 percent, 89.0 percent, 84.0 percent and 99.0 percent, respectively, when compared to the results of IFA. In addition, comparison of the results of ICA-BD and those of RT-PCR yielded relative indices of 79.5 percent for sensitivity and 95.4 percent for specificity, as well as PPV and NPV of 92.9 percent and 86.0 percent, respectively. Although RT-PCR has shown the best performance, the substantial agreement between the ICA-BD and IFA results suggests that ICA-BD, also in addition to being a rapid and facile assay, could be suitable as an alternative diagnostic screening for HRSV infection in children.

Virulence exaltation of Clostridium perfringens strains from bovines

Ten out of eighty-nine strains biochemically identified as Clostridium perfringens, isolated from bovine organs, were selected by their different results showed in toxigenicity test on mice. Those and the standard strains, ATCC types A, B, C, and D, had their virulence exalted through serial intramuscular inoculation into guinea pigs. Results showed that, for toxigenic strains (6), one or two passages were enough to cause exaltation, while for the atoxigenic (4), five or six inoculations were needed. Esterase electrophoresis of standard and isolated strains, with and without exaltation, was performed. Electrophoresis analysis permits the following conclusions: strains that do not show any clinical symptoms in mice, when exalted demonstrate decreased esterase activity; on the contrary, it is increased when correlated with animal symptoms.

Esterase electrophoresis of Clostridium perfringens bovine strains

Eighty-nine of 144 isolates of Clostridium perfringens abtained from 187 samples of 71 bovine in several Brazilian states were submitted to esterase electrophoresis for typing. Mobilites electrophoresis, as parameter, were settled down by isolates from ATCC pattern of types A, B, C, and D. Of the 89 isolates, 43 (48.3 per cent) were characterized as electrophoretic type A, 20 (22.5 per cent) as D, 18 (20.2 per cent) as C, and 3 (3.4 per cent) as B. Five (5.6 per cent) isolates did not identity with any type. Similarly esterase electrophoresis enabled the typing of 94.4 per cent of the isolates, demonstrating to be an appropriate method for animal sample analyses.

Toxigenicity characterization of Clostridium perfringens from bovine isolates

Clinical samples from 71 bovine from different Brazilian states were processed for the analysis of anaerobe organisms with emphasis on the isolation and characterization of Clostridium spp. From these eighty-nine Clostridium perfringens strains were recovered: 32 from liver, 19 from intestinal contents, 14 from kidney, 6 from rumen, 5 from nervous system, 4 from bone marrow, 2 from udder tract, blood, spleen and lung, and one from muscle. Four reference Clostridium perfringens types A, B, C, and D were used as controls in this study. All isolates were cultivated in appropriate media, and after centrifugation the supernatant and sediment were separated. From pure supernatant post exopolysaccharide (EPS) extraction, mouse toxigenicity tests were performed, determining protein and protein plus carbohydrate, respectively. ELISA was performed from sediments. The results showed that 51 (57.3 per cent) of the isolates were toxigenic to mice when inoculated by intraperitoneal route; bacteria from different organs had variable patterns of toxigenicity. Toxigenicity of EPS extracts was only expressed when protein concentration was 0.04 mg/mL and between 0.31 and 0.5 mg/mL for carbohydrate. Isolates were characterized as toxigenic when showing optimum protein and carbohydrate concentrations.

Tomografia axial computadorizada no diagnostico de abscesso pelvico pos-histerectomia vaginal. / Computed axial tomography in the diagnosis of pelvic abscess after vaginal hysterectomy

E descrito caso de abscesso pelvico pos-histerectomia vaginal cujo diagnostico foi documentado pela tomografia axial computadorizada A paciente foi reinternada no 8o. dia pos-operatorio com queixa de dor na fossa iliaca esquerda e diarreia. A temperatura era subfebril (37o.4) e o abdome encontrava-se discretamente distendido.O toque vaginal demonstrou fundo de saco vaginal discretamente abaulado e dolorido. Como nao melhorasse com a introducao de antibioticoterapia do largo espectro foram realizadas a ultra-sonografia e posteriormente a tomografia axial computadorizada da pelve. Tendo esta ultima revelado massa de conteudo solido heterogeneo com presenca de gas interposto entre baxiga e reto a paciente foi submetida a drenagem do fundo de saco de Douglas e recebeu alta curada 8 dias apos. A tomografia axial computadorizada e metodo de grande utilidade para localizar com precisao colecoes purulentas e instituir o tratamento adequedo das complicacoes infecciosas pos-operatorias em ginecologia