S. agalactiae (group B streptococci, GBS) is a major microbial pathogen in human neonates and causes invasive infections in pregnant women and immunocompromised individuals. The S. agalactiae β-hemolysin is regarded as an important virulence factor for the development of invasive disease. To examine the role of β-hemolysin in the interaction with professional phagocytes, the THP-1 monocytic cel...

The genetic diversity of 88 Streptococcus suis serotype 2 isolates which were recovered from various countries was examined by randomly amplified polymorphic DNA (RAPD) analysis with three primers. This bacterial collection included 80 isolates of porcine origin and 8 of human origin. This investigation allowed the identification of 23 RAPD types containing 1 to 30 isolates originating from one...

A medium consisting of a complete acid hydrolysate of casein supplemented with cystine, tryptophan, growth accessory factors, glucose, and inorganic salts, has been developed for the cultivation of Clostridium septicum. Toxin equivalent to 400 to 700 L.D(50) per ml. has been obtained regularly in this medium. The principal factors found to affect the yield of toxin are:- (a) Phase of strain emp...

Vibrio anguillarum is the causative agent of vibriosis in fish. Hemolysins of V. anguillarum have been considered virulence factors during infection. One hemolysin gene, vah1, has been previously identified but does not account for all hemolytic activity. The mini-Tn10Km mutagenesis performed with a vah1 mutant resulted in a hemolysin-negative mutant. The region surrounding the mutation was clo...

Culture supernatants of nontoxigenic nonepidemic clinical strains of Vibrio cholerae belonging to diverse serogroups were found to induce vacuolation of nonconfluent HeLa cells. The vacuoles became prominent 18 h after introduction of culture supernatant, and vacuolated cells survived for 48 h and then died. Only a fraction of the vacuolated cells took up neutral red dye, implying that there we...

the staphylococci are important pathogenic bacteria causing various infections in animals and human. hemolysin is one of the virulence factors of coagulase-positive (cps) and coagulase-negative staphylococci (cns). the aims of the study were to characterize hemolysins of staphylococcus spp. isolated from human and bovine origin, phenotypic- and genotypically. characterization of hemolysin pheno...

Beta-hemolysin production is a variable trait of the Lancefield group D streptococcus, Enterococcus faecalis. The E. faecalis hemolysin is encoded by large transmissible plasmids. The variable nature of this putative virulence factor provided an ideal system for testing its contribution in experimental endophthalmitis. In this study, isogenic E. faecalis strains were compared to determine wheth...

Skin barrier disruption and dermal inflammation are key phenotypes of atopic dermatitis (AD). Staphylococcus aureus secretes extracellular vesicles (EVs), which are involved in AD pathogenesis. Here, we evaluated the role of EVs-associated α-hemolysin derived from S. aureus in AD pathogenesis. α-hemolysin production from S. aureus was detected using western blot analyses. The cytotoxic activity...

The staphylococci are important pathogenic bacteria causing various infections in animals and human. Hemolysin is one of the virulence factors of coagulase-positive (CPS) and coagulase-negative staphylococci (CNS). The aims of the study were to characterize hemolysins of Staphylococcus spp. isolated from human and bovine origin, phenotypic- and genotypically. Characterization of hemolysin pheno...