The hidden lifestyles of Bacillus cereus and relatives

Abstract

SummaryBacillus cereus sensu lato , the species group comprising Bacillus anthracis , Bacillus thuringiensis and B. cereus ( sensu stricto ), has previously been scrutinized regarding interspecies genetic correlation and pathogenic characteristics. So far, little attention has been paid to analysing the biological and ecological properties of the three species in their natural environments. In this review, we describe the B. cereus sensu lato living in a world on its own; all B. cereus sensu lato can grow saprophytically under nutrientrich conditions, which are only occasionally found in the environment, except where nutrients are actively collected. As such, members of the B. cereus group have recently been discovered as common inhabitants of the invertebrate gut. We speculate that all members disclose symbiotic relationships with appropriate invertebrate hosts and only occasionally enter a pathogenic life cycle in which the individual species infects suitable hosts and multiplies almost unrestrained.

Comparative analysis of two-component signal transduction systems of Bacillus cereus, Bacillus thuringiensis and Bacillus anthracis

“…It has been proposed that B. anthracis evolved as a pathogen of warm-blooded animals early in the evolution of the B. cereus group, while the other members of this group kept exploiting more fluctuating environments (e.g. invertebrate guts, plant rhizospheres and supplemented soils) (Jensen et al, 2003;Turnbull, 1999). B. anthracis might have a more specialized pathogenic lifecycle than the other members of the B. cereus group.…”

“…Death of the host results in the release of large numbers of B. anthracis cells into the environment. These cells probably sporulate immediately upon contact with air, completing the B. anthracis life cycle (Jensen et al, 2003;Rasko et al, 2005). Specialization of B. anthracis as a pathogen could have reduced the range of environmental stimuli to which it is exposed.…”

“…Members of the B. cereus group are ubiquitously present in the environment and can adapt to a wide range of environmental conditions (Abee & Wouters, 1999;Jensen et al, 2003;Kotiranta et al, 2000). This raises the question of how these organisms are able to monitor these conditions and respond to them.…”

Anthrax in Western and Central African great apes

“…B. anthracis is not normally transmitted from one animal to another; the epidemiology of infection is usually linked to a particular source [e.g., Beatty et al, 2003;Lindeque & Turnbull, 1994], such as contaminated ground (grass) that is consumed by grazing animals, contaminated water, or the meat of other anthrax victims consumed by scavengers and humans. In addition, there are two significant presentations of anthrax: cutaneous and respiratory [Jensen et al, 2003]. Briefly, cutaneous anthrax is a less lethal form that results from infections in open wounds and has a local manifestation.…”

Caracterización bioquímica de microorganismos rizosféricos de plantas de vainilla con potencial como biofertilizantes.

“…cereus interactúa con otros microorganismos en la rizosfera de algunas plantas; estas se benefician de su presencia debido a la capacidad que tiene de inhibir el ataque de algunos patógenos y de promover su crecimiento (Jensen et al, 2003). Naturalmente produce los antibióticos zwittermicina A y kanosamina que inhiben el crecimiento de patógenos de plantas, como oomycetes, algunos hongos y diferentes especies de bacterias (Silo-Suh et al, 1994).…”