THE USE OF BACTERIA GROWN <i>IN VIVO</i> FOR STUDIES ON THE BASIS OF THEIR PATHOGENICITY

Smith, H. V.

doi:10.1146/annurev.mi.12.100158.000453

Cited by 55 publications

(28 citation statements)

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“…It has long been recognized that the gene expression profile of bacterial pathogens differs significantly during infection compared to the laboratory environment [1]. For example, a recent study of Listeria monocytogenes found that more than 1,000 genes were differentially expressed when comparing bacteria grown in a standard laboratory medium with the same bacteria recovered from mouse intestine [2].…”

Section: Introductionmentioning

confidence: 99%

A Combination of Independent Transcriptional Regulators Shapes Bacterial Virulence Gene Expression during Infection

et al. 2010

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Transcriptional regulatory networks are fundamental to how microbes alter gene expression in response to environmental stimuli, thereby playing a critical role in bacterial pathogenesis. However, understanding how bacterial transcriptional regulatory networks function during host-pathogen interaction is limited. Recent studies in group A Streptococcus (GAS) suggested that the transcriptional regulator catabolite control protein A (CcpA) influences many of the same genes as the control of virulence (CovRS) two-component gene regulatory system. To provide new information about the CcpA and CovRS networks, we compared the CcpA and CovR transcriptomes in a serotype M1 GAS strain. The transcript levels of several of the same genes encoding virulence factors and proteins involved in basic metabolic processes were affected in both ΔccpA and ΔcovR isogenic mutant strains. Recombinant CcpA and CovR bound with high-affinity to the promoter regions of several co-regulated genes, including those encoding proteins involved in carbohydrate and amino acid metabolism. Compared to the wild-type parental strain, ΔccpA and ΔcovRΔccpA isogenic mutant strains were significantly less virulent in a mouse myositis model. Inactivation of CcpA and CovR alone and in combination led to significant alterations in the transcript levels of several key GAS virulence factor encoding genes during infection. Importantly, the transcript level alterations in the ΔccpA and ΔcovRΔccpA isogenic mutant strains observed during infection were distinct from those occurring during growth in laboratory medium. These data provide new knowledge regarding the molecular mechanisms by which pathogenic bacteria respond to environmental signals to regulate virulence factor production and basic metabolic processes during infection.

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Section: Introductionmentioning

confidence: 99%

A Combination of Independent Transcriptional Regulators Shapes Bacterial Virulence Gene Expression during Infection

et al. 2010

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“…The present editors of Topley and Wilson (85) emphasize the importance of specific antibody rise during recovery as an important adjunct to Koch's postulates. H. Smith (71)(72)(73)(74)(75)(76)(77), a leading investigator of human infectious disease, supports Koch's dicta, as do most past and present followers of Koch. No one can deny the profound effect of this approach. It resulted, as stated earlier, in a successful curtailment of most major infectious diseases in developed countries.…”

Section: Introductionmentioning

confidence: 90%

Pathogenicity and virulence: another view

Isenberg

1988

Clin Microbiol Rev

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The concepts of pathogenicity and virulence have governed our perception of microbial harmfulness since the time of Pasteur and Koch. These concepts resulted in the recognition and identification of numerous etiological agents and provided natural and synthetic agents effective in therapy and prevention of diseases. However, Koch's postulates--the premier product of this view--place the onus of harmfulness solely on the microbial world. Our recent experiences with polymicrobic and nosocomial infections, legionellosis, and acquired immunodeficiency syndrome point to the host as the major determinant of disease. The principles of parasitism, enunciated by Theobold Smith, approximate more accurately the disturbances of the host-parasite equilibrium we designate as infection. Many complex attributes of microbial anatomy and physiology have been obscured by our dependency on the pure-culture technique. For example, bacterial attachment organelles and the production of exopolysaccharides enable microorganisms to interact with mammalian glycocalyces and specific receptors. In addition, selection, through the use of therapeutic agents, aids in the progression of environmental organisms to members of the intimate human biosphere, with the potential to complicate the recovery of patients. These factors emphasize further the pivotal significance of host reactions in infections. Parasitism, in its negative aspects, explains the emergence of "new" infections that involve harm to more than host organs and cells: we may encounter subtler infections that reveal parasitic and host cell nucleic acid interactions in a form of genomic parasitism.

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“…In the late 1940s, Cromartie et al confirmed the production of this toxin in vivo (Cromartie et al, 1947). The final steps were made by Smith and his associates in a series of outstanding studies where they succeeded in isolating and characterizing the nature and activities of the proteinaceous complex appearing in the plasma and exudates of infected animals (Harris- Smith et al, 1958;Smith, 1958;Stanley and Smith, 1963). They showed the complex to be composed of three protein factors: protecting antigen (PA, 83 kDa), oedema factor (EF, 89 kDa) and lethal factor (LF, 90 kDa).…”

Section: Pathophysiology Of Anthrax and Virulence Factorsmentioning

confidence: 99%

Dr. Jekyll and Mr. Hyde: A short history of anthrax

Schwartz

2009

Molecular Aspects of Medicine

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THE USE OF BACTERIA GROWN IN VIVO FOR STUDIES ON THE BASIS OF THEIR PATHOGENICITY

Cited by 55 publications

References 0 publications

A Combination of Independent Transcriptional Regulators Shapes Bacterial Virulence Gene Expression during Infection

A Combination of Independent Transcriptional Regulators Shapes Bacterial Virulence Gene Expression during Infection

Pathogenicity and virulence: another view

Dr. Jekyll and Mr. Hyde: A short history of anthrax

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