The Mycobacterium tuberculosis Complex

The M. tuberculosis complex refers to a number of genetically related human and animal pathogens that share 99.9 similarity at the nucleotide level and are indistinguishable by 16S rDNA sequencing. These includeM. tuberculosis, M. africanum, M. microti (voles), M. caprae (goats), M. bovis, as well as the BCG vaccine strains and a variety of isolates from unusual sources, such as M. pinnipedii (from seal lions and fur seals), and the dassie bacillus (from Procavia capensis, the hyrax, or...

Identification of PrfAControlled Target Genes

Availability of the L. monocytogenes genome sequence has made it possible to analyze transcription of all known or predicted open reading frames in response to specific genetic and or environmental conditions. Buchrieser and colleagues used DNA arrays containing 99 of all predicted open reading frames in the EGDe genome to identify genes that are differentially expressed in wild-type and prfA-deletion mutant strains (21). Gene expression was monitored in the presence or absence of charcoal or...

Origin of Virulence Strains and Species

The first bacteria on this planet probably evolved about 3.8 billion yr ago. Virulence factors started to evolve about 1 billion years ago during the coevolution of bacteria and unicellular eukaryotic organisms (10). Virulence factors are commonly defined as gene products that facilitate the bacterial interaction, subversion, and destruction of host cells, or the neutralization of host defense mechanisms. Bacterial toxins that are specific for highly conserved proteins like heterotrimeric G...

Conclusion and Clinical Perspectives

Innate immunity is an evolutionarily conserved response that antagonizes pathogen invasion, such as bacteria infection, in a swift and efficient way. To achieve this, recognition of pathogens is sorted by general molecular patterns and signals generated by such pattern recognition are then transmitted quickly to induce a legion of cytokines that amplify the inflammatory responses. This chapter focuses on the events of pathogen pattern recognition and signal transduction that lead to major...

Genome Comparisons of Diverse Staphylococcus aureus Strains

As with other pathogens, the genome of Staphylococcus aureus can be subdivided into core and accessory segments, comprising roughly 75 and 25 of the genome. Particular attention is given to the MRSA252 strain, which is phylogenetically distinct from other S. aureus genomes, is epidemic in the United Kingdom and North America, and is closely related to methicillin-susceptible clinical isolates that are hypervirulent in musculoskeletal infection models. This strain contains a number of unique or...

MyD88lndependent Signaling

Tbk1 Ikke Nfkb

Studies of the MyD88-independent pathways have been concentrated on TLR3 dsRNA- and TLR4 LPS-induced IRF3 activation and production of type I interferons, and downstream interferon-regulated genes such as IP-10 and GARG16 77 Fig. 6 . It appears that two newly discovered TIR-containing adaptors, TRIF and TRIF-related adaptor molecule TRAM , play critical roles in initiating this signaling cascade 9195 . TRAFZ-associated kinase T2K and IkB kinase IKKe are recruited by TRIF and Inflammatory...

NLinked Glycosylation of Multiple Proteins

Esi Tof Mass Spectrum Cellulose

Since the discovery of the first Bacterial N-linked glycosylation system in C. jejuni, the field has moved with remarkable progress. In contrast to the gene clusters involved in LOS, CPS, and O-linked flagellar glycosylation Fig. 1 , the genes required for the general N-linked protein glycosylation pathway are remarkably conserved Fig. 3 69 suggesting that the resulting glycans would also have the same structure. We described the complete structure of the N-linked glycan where Bac is...

Tlr4

In 1997, a paper published in Nature by Medzhitov et al. 12 jumpstarted the study of human TLR. These researchers identified the first mammalian TLR, a homolog of the Drosophila Toll protein, which was later named TLR4. They found that overexpression of a constitutively active TLR4 mutant induces nuclear factor kB NF-kB activation, and production of inflammatory cytokines is dependent on NF-kB. This publication initiated a new era of immunological research into the puzzle of innate immune...

DNA Microarray Analysis of Bacterial Pathogens

A DNA microarray is a high-density array of nucleic acid targets immobilized on a glass slide or a silicon chip. The nucleic acids are either denatured complementary DNA or genomic products amplified by PCR for spotted DNA arrays. For oligonucleotides arrays, oligonucleotides complementary to specific gene sequences are generally synthesized in situ. DNA microarray was first used in parallel detection and the analysis of the expression patterns of thousands of genes in plant tissues 7 and human...

TLR2 TLR6 and TLR1

TLR2 recognizes compounds from many microorganisms, including peptidoglycan PGN and lipoteichoic acid from Gram-positive bacteria e.g., Staphylococcus aureus or Bacillus subtilis , and lipoproteins from Gram-negative bacteria e.g., Borrelia burgdorferi, Treponema pallidum, and Mycoplasma fermentans 29-34 . These ligands for TLR2 were confirmed by several studies. Lipoproteins or PGN were found to induce NF-kB activation in human embryonic kidney 293 cells or Chinese hamster macrophages...

Pathogens and the Postgenomics

Although the generation and analysis of extensive volumes of sequence data is a major accomplishment, it is not an end in itself. Clearly, the motivation for sequencing genomes comes for a desire to understand the biology of living organisms. A major stimulus for research across all fields of biology is to understand and combat human diseases. It is not surprising then that many of the first organisms to be sequenced were important human pathogens. Indeed, given the small size and the paucity...