Membrane proteins from 25 strains of B. fragilis isolated in different laboratories in Northern Italy were examined by SDS-PAGE and isoelectrofocusing. The electrophoretic patterns of inner and outer membrane after Sarkosyl and SDS solubilization of all the isolates were consistently similar to that of the reference strain. The protein profiles of the different species belonging to the B. fragilis group are clearly distinguishable with negligible similarities. Our data clearly show that this approach is extremely helpful and reliable in providing additional verification of the identity of strains recognized by conventional tests. In this connection PAGIF analysis of triton solubilized isolated envelopes reduces technical time and difficulties, thus improving analytical accuracy.
Helicobacter pylori infection is common in the developing countries. The cagA gene is a marker of pathogenicity island (PAI) in H. pylori . The aim of this study was to determine the prevalence of cagA among dyspeptic patients in Bahrain directly from gastric biopsy and stool specimen.A total of 100 gastric biopsy samples, 16 clinical isolates and 44 faecal specimens were collected from Bahraini adult dyspeptic patients. cagA gene of H. pylori was assessed using polymerase chain reaction (PCR).The cagA gene was detected in 59 (59%) from biopsy specimens, 10 (62%) clinical isolates and in 10 (22.7%) faecal specimens. The detection of cagA positive H. pylori was significantly higher in patients with duodenal ulcer (80%) compared to those with other endoscopic finding (42%) (P < 0.05).Using PCR to detect cagA gene directly from biopsy is a rapid and reliable technique. However, using stool specimen for genotyping in our patients showed reduced sensitivity.
Among the most recent methods for investigation of proteins in biological fluids SDS Polyacrylamide-gel-electrophoresis and Isoelectrofocusing (IEF) have recently been introduced into laboratory practice. The present investigation has been performed on 20 samples of amniotic fluid obtained during normal pregnancies in the first and in the third trimester. The obtained results suggest that IEF analysis seems to have a selective advantage in allowing the separation of bands which can not be easily recognized with SDS electrophoresis. These bands detected by IEF and present in amniotic fluid during late pregnancy seem to be related to some low molecular weight lipoprotein fractions and we suggest that they might be used as a possible marker for monitoring fetal lung maturation. In conclusion we think that it would be of great interest to evaluate the usefulness of IEF analysis in examining A.F. obtained during pregnancies complicated by infections.
Mesophilic Aeromonas (Aeromonas hydrophila, Aeromonas sobria, Aeromonas caviae) have recently been considered important aetiological agents of human diseases, mainly gastrointestinal infections. Although several findings have pointed out the significance of this group of microorganisms as enteric pathogens and suggested the presence of virulence factors, epidemiological and clinical studies are limited by the difficulty of correctly identifying mesophilic Aeromonas at the species level. SDS-PAGE of radiolabelled total protein profiles and bacterial enzymatic activities were used to type 31 clinical isolates (6 A. hydrophila, 7 A. sobria and 18 A. caviae) from patients with gastroenteritis and from healthy controls. Analysis of SDS-PAGE protein patterns, reinforced by the UPGMA-grouping system (AMBIS software) provided a good characterization of A. caviae strains as a homogeneous group of microorganisms, possessing significant differences from the other two species of mesophilic Aeromonas, in good agreement with biochemical and enzymatic tests. Data obtained in analyzing A. sobria protein profiles clearly showed two groups, with a correlation coefficient (CC) = 0.70, which in our experience is a doubtful value for assigning two strains to the same species. Strains biochemically identified as A. hydrophila showed a CC = 0.64, which is equally not acceptable for species assignment. Inter-species comparison highlighted this heterogeneity, showing two mixed subgroups, both containing strains that were assigned to A. sobria and A. hydrophila species on the basis of biochemical features.(ABSTRACT TRUNCATED AT 250 WORDS)
