Detection of differential gene expression in biofilm-forming versus planktonic populations of Staphylococcus aureus using micro-representational-difference analysis.

Microbial proliferation and biofilm formation on biologic or inert substrates are characteristics of invasive Staphylococcus aureus infections and is associated with phenotypic alterations such as reduced antimicrobial susceptibility. To identify genes which are typically expressed in biofilms, a micro-representational-difference analysis (micro-RDA) was adapted for gram-positive bacteria and used with cDNA derived from populations of S. aureus DSM 20231 growing in a biofilm or plankonically.

Complete genome sequence of Pseudomonas aeruginosa PAO1, an opportunistic pathogen.

Pseudomonas aeruginosa is a ubiquitous environmental bacterium that is one of the top three causes of opportunistic human infections. A major factor in its prominence as a pathogen is its intrinsic resistance to antibiotics and disinfectants. Here we report the complete sequence of P.

Staphylococcus aureus genetic loci impacting growth and survival in multiple infection environments.

The Gram-positive bacterium Staphylococcus aureus infects diverse tissues and causes a wide spectrum of diseases, suggesting that it possesses a repertoire of distinct molecular mechanisms promoting bacterial survival in disparate in vivo environments. Signature-tag transposon mutagenesis screening of a 1520-member library identified numerous S. aureus genetic loci affecting growth and survival in four complementary animal infection models including mouse abscess, bacteraemia and wound and rabbit endocarditis.

VH usage and somatic hypermutation in peripheral blood B cells of patients with rheumatoid arthritis (RA).

The human antibody repertoire has been demonstrated to have a marked V-gene-dependent bias that is conserved between individuals. In RA patients, certain heavy chain V genes (VH) have been found to be preferentially used for encoding autoantibodies. To determine if such preferential use of VH genes in autoantibodies is associated with a general distortion of the V gene repertoire in RA patients, the VH composition of peripheral blood B cells was analysed among four RA patients and four age- and sex-matched healthy controls.

Immunoglobulin heavy chain variable region gene usage in bone marrow transplant recipients: lack of somatic mutation indicates a maturational arrest.

Many recipients of bone marrow transplant (BMT) make normal amounts of serum immunoglobulin but are deficient in generating specific antibody responses to exogenous stimuli. To determine if abnormal usage of VH genes contributes to this immunodeficiency, the usage of VH genes was determined in peripheral blood B cells of four BMT recipients, two of whom had developed chronic graft versus host disease. The pattern of usage of VH3 or VH4 genes assessed at either 90 days or approximately 1 year after transplant was similar to that observed in healthy subjects and was marked by the over utilization of two elements, one VH3 and one VH4.