Evaluation of Vitek-2 and MicroScan ASTs directly from positive blood culture: A cost-effective 24-h reduction for Enterobacterales and staphylococci.

The reduction of antimicrobial susceptibility testing (AST) time-to-result is a central need, especially in sepsis treatment. The current automated rapid ASTs are still too expensive for many laboratories. We aimed to evaluate three pre-treatment methods for a same-day inoculation on both automated AST platforms available in our laboratory.

Dynamics of HIV-1 POL antibodies after ART in chronic HIV-1 infection.

The aim of this retrospective study was to evaluate Western Blot (WB) antibody response against HIV-1 Pol proteins in people on ≥12 months of Antiretroviral Therapy (ART) and factors associated with a negative HIV-1 Pol response or with its seroreversion from positive to negative. Multivariate logistic regression models were performed to assess factors associated with a negative HIV-1 Pol or with HIV-1 Pol seroreversion. A negative HIV-1 Pol was found in 88 (16.

Proteomic characterization of the Rhodobacter sphaeroides 2.4.1 photosynthetic membrane: identification of new proteins.

The Rhodobacter sphaeroides intracytoplasmic membrane (ICM) is an inducible membrane that is dedicated to the major events of bacterial photosynthesis, including harvesting light energy, separating primary charges, and transporting electrons. In this study, multichromatographic methods coupled with Fourier transform ion cyclotron resonance mass spectrometry, combined with subcellular fractionation, was used to test the hypothesis that the photosynthetic membrane of R. sphaeroides 2.

Mycobacterial bacilli are metabolically active during chronic tuberculosis in murine lungs: insights from genome-wide transcriptional profiling.

Chronic tuberculosis represents a major health problem for one-third of the world's population today. A key question relevant to chronic tuberculosis is the physiological status of Mycobacterium tuberculosis during this important stage of infection. To examine the molecular bases of chronic tuberculosis and the role of host immunity in mycobacterial growth, we determined the mycobacterial transcriptional profiles during chronic and reactivation phases of murine tuberculosis using in vivo microarray analysis (IVMA).

Specificity of DNA binding and dimerization by CspE from Escherichia coli.

The CspE protein from Escherichia coli K12 is a single-stranded nucleic acid-binding protein that plays a role in chromosome condensation in vivo. We report here that CspE binds to single-stranded DNA containing 6 or more contiguous dT residues with high affinity (K(D) < 30 nM). The interactions are predominantly through base-specific contacts.

Development of the bacterial photosynthetic apparatus.

Anoxygenic photosynthetic bacteria have provided us with crucial insights into the process of solar energy capture, pathways of metabolic and societal importance, specialized differentiation of membrane domains, function or assembly of bioenergetic enzymes, and into the genetic control of these and other activities. Recent insights into the organization of this bioenergetic membrane system, the genetic control of this specialized domain of the inner membrane and the process by which potentially photosynthetic and non-photosynthetic cells protect themselves from an important class of reactive oxygen species will provide an unparalleled understanding of solar energy capture and facilitate the design of solar-powered microbial biorefineries.

Application of the accurate mass and time tag approach to the proteome analysis of sub-cellular fractions obtained from Rhodobacter sphaeroides 2.4.1. Aerobic and photosynthetic cell cultures.

The high-throughput accurate mass and time (AMT) tag proteomic approach was utilized to characterize the proteomes for cytoplasm, cytoplasmic membrane, periplasm, and outer membrane fractions from aerobic and photosynthetic cultures of the gram-nagtive bacterium Rhodobacter sphaeroides 2.4.1.

Comparison of aerobic and photosynthetic Rhodobacter sphaeroides 2.4.1 proteomes.

The analysis of proteomes from aerobic and photosynthetic Rhodobacter sphaeroides 2.4.1 cell cultures by liquid chromatography-mass spectrometry yielded approximately 6,500 high confidence peptides representing 1,675 gene products (39% of the predicted proteins).

Identification of genes required for recycling reducing power during photosynthetic growth.

Photosynthetic organisms have the unique ability to transform light energy into reducing power. We study the requirements for photosynthesis in the alpha-proteobacterium Rhodobacter sphaeroides. Global gene expression analysis found that approximately 50 uncharacterized genes were regulated by changes in light intensity and O\2 tension, similar to the expression of genes known to be required for photosynthetic growth of this bacterium.

The role of dor gene products in controlling the P2 promoter of the cytochrome c2 gene, cycA, in Rhodobacter sphaeroides.

This study explores the regulatory networks controlling anaerobic energy production by the facultative phototroph Rhodobacter sphaeroides. The specific aim was to determine why activity of the P2 promoter for the gene (cycA) encoding the essential photosynthetic electron carrier, cytochrome c(2), is decreased when the alternative electron acceptor DMSO is added to photosynthetically grown cells. The presence of DMSO is believed to activate the DorR response regulator, which controls expression of proteins required to reduce DMSO.