Swarming behavior of and hemolysin BL secretion by Bacillus cereus.

An association between swarming and hemolysin BL secretion was observed in a collection of 42 Bacillus cereus isolates (P=0.029). The highest levels of toxin were detected in swarmers along with swarm cell differentiation (P=0.

Forensic application of microbiological culture analysis to identify mail intentionally contaminated with Bacillus anthracis spores.

The discovery of a letter intentionally filled with dried Bacillus anthracis spores in the office of a United States senator prompted the collection and quarantine of all mail in congressional buildings. This mail was subsequently searched for additional intentionally contaminated letters. A microbiological sampling strategy was used to locate heavy contamination within the 642 separate plastic bags containing the mail.

Failure of intravitreal dexamethasone to diminish inflammation or retinal toxicity in an experimental model of Bacillus cereus endophthalmitis.

Purpose: To determine whether the usual clinical dose of intravitreal dexamethasone can attenuate intraocular inflammation and retinal necrosis in a rabbit model of fulminant Bacillus cereus endophthalmitis induced by crude exotoxins.

Methods: Thirty-six eyes from pigmented mongrel rabbits received intravitreal injections of varying concentrations of crude B. cereus exotoxins with or without concomitant injections of 400 microg of dexamethasone sodium phosphate (0.

Fluorescent amplified fragment length polymorphism analysis of Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis isolates.

DNA from over 300 Bacillus thuringiensis, Bacillus cereus, and Bacillus anthracis isolates was analyzed by fluorescent amplified fragment length polymorphism (AFLP). B. thuringiensis and B.

Requirement of flhA for swarming differentiation, flagellin export, and secretion of virulence-associated proteins in Bacillus thuringiensis.

Bacillus thuringiensis is being used worldwide as a biopesticide, although increasing evidence suggests that it is emerging as an opportunistic human pathogen. While phospholipases, hemolysins, and enterotoxins are claimed to be responsible for B. thuringiensis virulence, there is no direct evidence to indicate that the flagellum-driven motility plays a role in parasite-host interactions.

Swarming motility in Bacillus cereus and characterization of a fliY mutant impaired in swarm cell differentiation.

This report describes a new behavioural response of Bacillus cereus that consists of a surface-induced differentiation of elongated and hyperflagellated swarm cells exhibiting the ability to move collectively across the surface of the medium. The discovery of swarming motility in B. cereus paralleled the isolation of a spontaneous non-swarming mutant that was found to carry a deletion of fliY, the homologue of which, in Bacillus subtilis, encodes an essential component of the flagellar motor-switch complex.

Cooperative, synergistic and antagonistic haemolytic interactions between haemolysin BL, phosphatidylcholine phospholipase C and sphingomyelinase from Bacillus cereus.

Haemolysis of erythrocytes from different species (sheep, bovine, swine and human), caused by various combinations of phosphatidylcholine (PC)-preferring phospholipase C (PC-PLC), sphingomyelinase (SMase) and the three-component, pore-forming toxin haemolysin BL (HBL) from Bacillus cereus was analysed. The lytic potency of HBL did not correlate with phospholipid (PL) content, but lysis by the individual or combined enzymes did. SMase alone lysed ruminant erythrocytes, which contain 46-53% sphingomyelin (SM).

Tripartite haemolysin BL: isolation and characterization of two distinct homologous sets of components from a single Bacillus cereus isolate.

Haemolysin BL (HBL), a three-component enterotoxic/necrotizing/vascular permeability toxin, is a likely virulence factor of Bacillus cereus diarrhoeal food poisoning and necrotic infections. This paper describes the isolation of two distinct homologous sets of all three HBL components from a single B. cereus isolate, MGBC 145.