High homology of membrane proteins electrophoretic pattern in Bacteroides fragilis as confirmed by various...

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.