FtsA G50E mutant suppresses the essential requirement for FtsK during bacterial cell division in .

In , the N-terminal domain of the essential protein FtsK (FtsK) is proposed to modulate septum formation through the formation of dynamic and essential protein interactions with both the Z-ring and late-stage division machinery. Using genomic mutagenesis, complementation analysis, and pull-down assays, we aimed to identify protein interaction partners of FtsK essential to its function during division. Here, we identified the cytoplasmic Z-ring membrane anchoring protein FtsA as a direct protein-protein interaction partner of FtsK.

Single-Nucleotide Polymorphisms Found in the migA and wbpX Glycosyltransferase Genes Account for the Intrinsic Lipopolysaccharide Defects Exhibited by Pseudomonas aeruginosa PA14.

Unlabelled: Pseudomonas aeruginosa PA14 is widely used by researchers in many laboratories because of its enhanced virulence over strain PAO1 in a wide range of hosts. Although lipopolysaccharide (LPS) is an important virulence factor of all P. aeruginosa strains, the LPS of PA14 has not been characterized fully.

Serum IgG response in calves to the putative pneumonic virulence factor Gs60 of Mannheimia haemolytica A1.

Bovine pneumonic pasteurellosis vaccines incorporate various antigens of Mannheimia haemolytica, including the acknowledged virulence factor leukotoxin (Lkt), and Gs60, a surface lipoprotein. To examine the role of antibodies to Gs60 in protection, an enzyme-linked immunosorbent assay (ELISA) was developed for retrospective analysis of serum samples from previous trials in which vaccines containing native or recombinant Gs60 were administered parenterally. The analysis revealed a positive correlation between the titer of antibodies to Gs60 and protection against experimental challenge in both vaccinates and naturally exposed controls.

In vivo gene expression in Mannheimia haemolytica A1 during a time-course trial in the bovine host.

The objective of this study is to examine the expression of Mannheimia haemolytica genes over time during the early stage of infection. In addition, gene expression at different sites of infection in the bovine host was examined. A time-course experiment was designed to collect pharyngeal swabs and lung washings from the same animals over two time points.

A snap-shot of Mannheimia hemolytica A1 gene expression during infection in the bovine host.

It is expected that Mannheimia hemolytica A1 expresses a particular collection of genes during infection in the host. The bacterial gene products are produced in the in vivo environment to facilitate growth and survival. Here, we examined gene expression by M.

Identification of putative two-component regulatory systems in the bovine pathogen Mannheimia haemolytica A1, and preliminary characterization of the NarQ/P system.

The complete genome sequence of the bovine pathogen Mannheimia haemolytica A1 was analyzed by blast searches for the presence of two-component regulatory system proteins. Five complete sets of putative two-component systems were identified, and the NarQ/P system was further investigated. in silico analysis of the NarQ and NarP proteins showed features that are typical of the sensor and response regulator proteins.

Characterization of Staphylococcus aureus isolates with a partial or complete absence of staphylococcal cassette chromosome elements.

Detection of methicillin-resistant Staphylococcus aureus (MRSA) by single-locus PCR assays that target the extremity of the staphylococcal cassette chromosome-mec (SCCmec) and part of the adjacent S. aureus-specific open reading frame gene (orfX) is a significant diagnostic advancement, since it provides real-time detection directly from screening specimens. However, isolates harboring mecA deletions within SCCmec may result in false-positive identification of MRSA in these assays.

Analysis of a collagen-binding trimeric autotransporter adhesin from Mannheimia haemolytica A1.

A locus that codes for a high-molecular-weight adhesin was previously isolated from Mannheimia haemolytica A1. In this study, we showed that this locus, named ahs, codes for two proteins (AhsA and AhsB) that exhibit characteristics of a trimeric autotransporter adhesin. Sequence analysis of AhsA showed the presence of 21 collagen-binding motifs in the protein.

Expression of a modified Mannheimia haemolytica GS60 outer membrane lipoprotein in transgenic alfalfa for the development of an edible vaccine against bovine pneumonic pasteurellosis.

The GS60 antigen is one of the protective antigens of Mannheimia haemolytica A1. GS60 contains conserved domains belonging to the LppC family of bacterial outer membrane lipoproteins. A high antibody titer to GS60 has been shown to be significantly correlated with resistance to pneumonic pasteurellosis.

The outer membrane protein OmpA of Mannheimia haemolytica A1 is involved in the binding of fibronectin.

An enzyme-linked immunosorbent assay using bovine fibronectin as the substrate was used to demonstrate that Mannheimia haemolytica A1 binds to fibronectin. This binding to fibronectin was specific as no binding was observed with bovine fibrinogen. The binding to fibronectin was not observed if the M.

Analysis of in vivo expressed genes in Mannheimia haemolytica A1.

The expression of Mannheimia haemolytica A1 genes during in vivo growth was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) using total RNA extracted directly from M. haemolytica A1 recovered from pneumonic lungs of cattle. Primers specific for three groups of genes were used.

Cloning of a gene fragment encoding bovine complement component C3d with expression and characterization of derived fusion proteins.

The gene fragment coding for bovine C3d gene (boC3d) was cloned and expressed as a component of fusion proteins destined for use in vaccine studies in cattle, and for in vitro experiments. This fragment of complement protein C3 (C3d) has been shown to enhance B cell responses when complexed with antigen. Three potential vaccine constructs were engineered to contain one, two or three boC3d units linked to a fragment of the leukotoxin of Mannheimia haemolytica A1, an economically important pathogen of cattle that causes a fibrinous pneumonia in calves.

Construction and analysis of a Mannheimia haemolytica A1 luxS mutant.

Mannheimia haemolytica A1 is the causative agent of bovine pneumonic pasteurellosis, a major cause of sickness, death, and economic loss to the feedlot cattle industry. M. haemolytica A1 produces autoinducer-2 (AI-2) like molecules that are capable of inducing quorum sensing system 2 of Vibrio harveyi.

DNA-containing membrane vesicles of Pseudomonas aeruginosa PAO1 and their genetic transformation potential.

Natural membrane vesicles (n-MVs) produced by Pseudomonas aeruginosa PAO1 and PAO1 carrying plasmid pAK1900 (p-MVs) were purified and analysed for DNA content. The MVs were isolated by a procedure designed to ensure no cellular contamination from the parent MV-producing cells. Fluorometry analysis revealed that p-MVs were associated with 7.

Efficacy of recombinant sialoglycoprotease in protection of cattle against pneumonic challenge with Mannheimia (Pasteurella) haemolytica A1.

Secreted recombinant sialoglycoprotease fusion protein (Gcp-F) of Mannheimia (Pasteurella) haemolytica A1 was examined for its ability to protect cattle from experimental challenge with M. haemolytica A1. Five M.

Novel protease produced by a Pasteurella trehalosi serotype 10 isolate from a pneumonic bighorn sheep: characteristics and potential relevance to protection.

A strain of Pasteurella trehalosi serotype 10, E(CO)-100, isolated from a bighorn sheep that had succumbed to pneumonic pasteurellosis during an epizootic, was compared to well-characterized strains of P. trehalosi serotype 10 and Mannheimia haemolytica serotype 1. The gene for leukotoxin A (lktA) from E(CO)-100 was sequenced and found to be identical on an amino acid basis to a published sequence for lktA from P.

Mannheimia haemolytica serotype 1 and Pasteurella trehalosi serotype 10 culture supernatants contain fibrinogen-binding proteins.

Fibrinogen-binding proteins were found in the culture supernatants of Mannheimia haemolytica serotype 1 (ATCC 43270) and Pasteurella trehalosi serotype 10 (ECO-100). Sheep fibrinogen was biotinylated and shown to bind to proteins in the culture supernatants by modified western blot. Fibrinogen-binding proteins in the culture supernatant may be important virulence factors leading to the characteristic fibrinous pneumonia caused by these organisms and may be critical antigenic targets for immune prophylaxis.

Construction and characterization of an acapsular mutant of Mannheimia haemolytica A1.

The nmaA and nmaB genes, which code for UDP-GlcNAc-2-epimerase and UDP-ManNAc-dehydrogenase, respectively, are involved in capsular polysaccharide biosynthesis in Mannheimia haemolytica A1. A chloramphenicol resistance (Cm(r)) cassette cloned behind an M. haemolytica A1 promoter, plpcat, was created and used to interrupt nmaA and nmaB.

Studies on the production of quorum-sensing signal molecules in Mannheimia haemolytica A1 and other Pasteurellaceae species.

The bioluminescence assay system using Vibrio harveyi reporter strains were used to examine quorum-sensing autoinducer (AI) activity from Mannheimia haemolytica A1 cell-free culture supernatant. We showed that M. haemolytica A1 cell-free culture supernatant contains molecules that can stimulate the quorum-sensing system that regulates the expression of the luciferase operon in V.

A putative iron-regulated TonB-dependent receptor of Mannheimia (Pasteurella) haemolytica A1: possible mechanism for phase variation.

A recombinant plasmid that codes for a novel iron receptor protein (Irp) of Mannheimia (Pasteurella) haemolytica A1 was isolated by the partial complementation of an Escherichia coli fur mutant. The deduced amino acid sequence of Irp exhibited characteristics typical of TonB-dependent receptors. These include: a TonB-box at the N-terminal; a 50 amino acid region homologous to the "plug" domain of the E.