The cytotoxic potential of Bacillus cereus strains of various origins

Bacterial response to nitric oxide (NO) is of major importance for bacterial survival. NO stress is a main actor of the eukaryotic immune response and several pathogenic bacteria have developed means for detoxification and repair of the damages caused by NO. However, bacterial mechanisms of NO resistance by Gram-positive bacteria are poorly described. In the opportunistic foodborne pathogen Bacillus cereus, genome sequence analyses did not identify homologs to known NO reductases and transcriptional regulators, such as NsrR, which orchestrate the response to NO of other pathogenic or non-pathogenic bacteria. Using a transcriptomic approach, we investigated the adaptation of B. cereus to NO stress. A cluster of 6 genes was identified to be strongly up-regulated in the early phase of the response. This cluster contains an iron-sulfur cluster repair enzyme, a nitrite reductase and three enzymes involved in siroheme biosynthesis. The expression pattern and close genetic localization suggest a functional link between these genes, which may play a pivotal role in the resistance of B. cereus to NO stress during infection.

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“…Bacillus cereus is an emerging pathogen capable of resisting macrophages [ 41 ]. During phagocytosis, nitric oxide is secreted.…”

Section: Discussionmentioning

confidence: 99%

Implication of a Key Region of Six Bacillus cereus Genes Involved in Siroheme Synthesis, Nitrite Reductase Production and Iron Cluster Repair in the Bacterial Response to Nitric Oxide Stress

Porrini

Guérin

Tran

et al. 2021

IJMS

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“…This study includes 39 B. cereus strains associated with foodborne illness [1], 35 strains isolated from human patients following systemic or local infections [9] and 21 non-pathogenic strains [11,22] (Sup Table 1). We have previously shown a correlation between cytotoxicity and virulence [21]. Nevertheless, although these strains had previously been shown to be weakly cytotoxic to human cells and to have reduced virulence in an insect infection model, this does not rule out their potential ability to produce symptoms in specific vulnerable populations.…”

Section: Isolate Informationmentioning

confidence: 93%

“…To date, the above described determinants were not sufficient to completely explain the virulence of B. cereus [21] and there are currently no markers, either alone or in combination, to differentiate pathogenic from non-pathogenic strains. In this work, we took advantage of a well characterized collection of 95 B. cereus strains and compared pathogenic (FBO and clinical) with non-pathogenic strains.…”

Section: Introductionmentioning

confidence: 99%

New genetic biomarkers to differentiate non-pathogenic from clinically relevant Bacillus cereus strains

Kavanaugh

Glasset

Dervyn

et al. 2022

Clinical Microbiology and Infection

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“…The pathogenic potential of B . cereus is thus extremely variable, with some strains being harmless and others lethal [ 11 ].…”

Section: Introductionmentioning

confidence: 99%

“…B . cereus strains that induced severe gastrointestinal or non-gastrointestinal disorders do not carry neither hbl , ces , hlyII , cytK1 nor cytK2 genes and did not produce the Nhe protein, implying that other still unknown factors were responsible for their pathogenicity [ 1 , 11 ].…”

Section: Introductionmentioning

confidence: 99%

The pathogenic biomarker alcohol dehydrogenase protein is involved in Bacillus cereus virulence and survival against host innate defence

et al. 2022

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Bacillus cereus is a spore forming bacteria recognized among the leading agents responsible for foodborne outbreaks in Europe. B. cereus is also gaining notoriety as an opportunistic human pathogen inducing local and systemic infections. The real incidence of such infection is likely underestimated and information on genetic and phenotypic characteristics of the incriminated strains is generally scarce. We have recently analyzed a large strain collection of varying pathogenic potential. Screening for biomarkers to differentiate among clinical and non-clinical strains, a gene encoding an alcohol dehydrogenase-like protein was identified among the leading candidates. This family of proteins has been demonstrated to be involved in the virulence of several bacterial species. The relevant gene was knocked out to elucidate its function with regards to resistance to host innate immune response, both in vitro and in vivo. Our results demonstrate that the adhB gene plays a significant role in resistance to nitric oxide and oxidative stress in vitro, as well as its pathogenic ability with regards to in vivo toxicity. These properties may explain the pathogenic potential of strains carrying this newly identified virulence factor.

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The cytotoxic potential of Bacillus cereus strains of various origins

Cited by 23 publications

References 39 publications

Implication of a Key Region of Six Bacillus cereus Genes Involved in Siroheme Synthesis, Nitrite Reductase Production and Iron Cluster Repair in the Bacterial Response to Nitric Oxide Stress

Implication of a Key Region of Six Bacillus cereus Genes Involved in Siroheme Synthesis, Nitrite Reductase Production and Iron Cluster Repair in the Bacterial Response to Nitric Oxide Stress

New genetic biomarkers to differentiate non-pathogenic from clinically relevant Bacillus cereus strains

The pathogenic biomarker alcohol dehydrogenase protein is involved in Bacillus cereus virulence and survival against host innate defence

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