BaeR participates in cephalosporins susceptibility by regulating the expression level of outer membrane proteins in Escherichia coli

Abstract The two-component system BaeSR participates in antibiotics resistance of Escherichia coli. To know whether the outer membrane proteins involve in the antibiotics resistance mediated by BaeSR, deletion of acrB was constructed and the recombined plasmid p-baeR was introduced into E. coli K12 and K12△acrB. Minimum inhibitory concentrations (MICs) of antibacterial agents were determined by 2-fold broth micro-dilution method. Gene expressions related with major outer membrane proteins and multidrug efflux pump-related genes were determined by real-time quantitative reverse transcription polymerase chain reaction. The results revealed that the MICs of K12ΔacrB to the tested drugs except for gentamycin and amikacin decreased 2- to 16.75-folds compared with those of K12. When BaeR was overexpressed, the MICs of K12ΔacrB/p-baeR to ceftiofur and cefotaxime increased 2.5- and 2-fold, respectively, compared with their corresponding that of K12△acrB. At the same time, the expression levels of ompC, ompF, ompW, ompA and ompX showed significant reduction in K12ΔacrB/p-baeR as compared with K12△acrB. Moreover, the expression levels of ompR, marA, rob and tolC also significantly ‘decreased’ in K12ΔacrB/p-baeR. These findings indicated that BaeR overproduction can decrease cephalosporins susceptibility in acrB-free E. coli by decreasing the expression level of outer membrane proteins.

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Localized adherence by enteropathogenic Escherichia coli is an inducible phenotype associated with the expression of new outer membrane proteins.

Journal of Experimental Medicine ◽

10.1084/jem.174.5.1167 ◽

1991 ◽

Vol 174 (5) ◽

pp. 1167-1177 ◽

Cited By ~ 64

Author(s):

J Vuopio-Varkila ◽

G K Schoolnik

Keyword(s):

Escherichia Coli ◽

Membrane Proteins ◽

Outer Membrane ◽

De Novo ◽

Outer Membrane Proteins ◽

Temporal Correlation ◽

Enteropathogenic Escherichia Coli ◽

E Coli

Enteropathogenic Escherichia coli grow as discrete colonies on the mucous membranes of the small intestine. A similar pattern can be demonstrated in vitro; termed localized adherence (LA), it is characterized by the presence of circumscribed clusters of bacteria attached to the surfaces of cultured epithelial cells. The LA phenotype was studied using B171, an O111:NM enteropathogenic E. coli (EPEC) strain, and HEp-2 cell monolayers. LA could be detected 30-60 min after exposure of HEp-2 cells to B171. However, bacteria transferred from infected HEp-2 cells to fresh monolayers exhibited LA within 15 min, indicating that LA is an inducible phenotype. Induction of the LA phenotype was found to be associated with de novo protein synthesis and changes in the outer membrane proteins, including the production of a new 18.5-kD polypeptide. A partial NH2-terminal amino acid sequence of this polypeptide was obtained and showed it to be identical through residue 12 to the recently described bundle-forming pilus subunit of EPEC. Expression of the 18.5-kD polypeptide required the 57-megadalton enteropathogenic E. coli adherence plasmid previously shown to be required for the LA phenotype in vitro and full virulence in vivo. This observation, the correspondence of the 18.5-kD polypeptide to an EPEC-specific pilus protein, and the temporal correlation of its expression with the development of the LA phenotype suggest that it may contribute to the EPEC colonial mode of growth.

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e-Membranome: a Database for Genome-Wide Analysis of Escherichia coli Outer Membrane Proteins

Current Pharmaceutical Biotechnology ◽

10.2174/1389201021666200610105549 ◽

2020 ◽

Vol 21 ◽

Author(s):

Kang Mo Lee ◽

Seung-Hak Cho ◽

Cheorl-Ho Kim ◽

Jong Hyun Kim ◽

Sung Soon Kim

Keyword(s):

Escherichia Coli ◽

Membrane Proteins ◽

Outer Membrane ◽

Outer Membrane Proteins ◽

3D Structure ◽

Glycan Array ◽

Epitope Region ◽

E Coli ◽

Genome Wide ◽

A Genome

Objectives: Lectin-like adhesins of enteric bacterial pathogens such as Escherichia coli are an attractive target for vaccine or drug development. Here, we have developed e-Membranome as a database of genome-wide putative adhesins in Escherichia coli (E. coli). Methods: The outer membrane adhesins were predicted from the annotated genes of Escherichia coli strains using the PSORTb program. Further analysis was performed using Interproscan and the String database. The candidate proteins can be investigated for homology modeling of the three-dimensional (3D) structure (I-TASSER version 5.1), epitope region (ABCpred), and the glycan array. Results: e-Membranome is implemented using the Django (version 2.2.5) framework. The Web Application Server Apache Tomcat 6.0 is integrated in the platform on Ubuntu Linux (version 16.04). MySQL database (version 5.7) is used as a database engine. The information of homology model of the 3D structure, epitope region, and affinity information from the glycan array will be stored in the e-Membranome database. As a case study, we performed a genome-wide screening of outer membrane-embedded proteins from the annotated genes of E. coli using the e-Membranome pipeline. Conclusion: This platform is expected to be a valuable resource for advancing research of outer membrane proteins for the construction of lectin-glycan interaction network of E. coli. In addition, the e-Membranome pipeline can be extended to other similar biological systems that need to address host-pathogen interactions.

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Helical Disposition of Proteins and Lipopolysaccharide in the Outer Membrane of Escherichia coli

Journal of Bacteriology ◽

10.1128/jb.187.6.1913-1922.2005 ◽

2005 ◽

Vol 187 (6) ◽

pp. 1913-1922 ◽

Cited By ~ 50

Author(s):

Anindya S. Ghosh ◽

Kevin D. Young

Keyword(s):

Escherichia Coli ◽

Membrane Proteins ◽

Outer Membrane ◽

Fluorescent Dyes ◽

Cell Envelope ◽

Outer Membrane Proteins ◽

E Coli ◽

Physiological Processes ◽

Side Walls

ABSTRACT In bacteria, several physiological processes once thought to be the products of uniformly dispersed reactions are now known to be highly asymmetric, with some exhibiting interesting geometric localizations. In particular, the cell envelope of Escherichia coli displays a form of subcellular differentiation in which peptidoglycan and outer membrane proteins at the cell poles remain stable for generations while material in the lateral walls is diluted by growth and turnover. To determine if material in the side walls was organized in any way, we labeled outer membrane proteins with succinimidyl ester-linked fluorescent dyes and then grew the stained cells in the absence of dye. Labeled proteins were not evenly dispersed in the envelope but instead appeared as helical ribbons that wrapped around the outside of the cell. By staining the O8 surface antigen of E. coli 2443 with a fluorescent derivative of concanavalin A, we observed a similar helical organization for the lipopolysaccharide (LPS) component of the outer membrane. Fluorescence recovery after photobleaching indicated that some of the outer membrane proteins remained freely diffusible in the side walls and could also diffuse into polar domains. On the other hand, the LPS O antigen was virtually immobile. Thus, the outer membrane of E. coli has a defined in vivo organization in which a subfraction of proteins and LPS are embedded in stable domains at the poles and along one or more helical ribbons that span the length of this gram-negative rod.

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Isolation and characterization of isogenic E. coli strains with alterations in the level of one or more major outer membrane proteins

Canadian Journal of Microbiology ◽

10.1139/m79-065 ◽

1979 ◽

Vol 25 (3) ◽

pp. 423-427 ◽

Cited By ~ 13

Author(s):

John Foulds ◽

Tuu-Jyi Chai

Keyword(s):

Escherichia Coli ◽

Membrane Proteins ◽

Outer Membrane ◽

Outer Membrane Proteins ◽

E Coli ◽

Isolation And Characterization

Nearly isogenic Escherichia coli strains which carry mutations leading to altered levels of major outer membrane proteins have been prepared and genetically characterized.

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MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa

International Journal of Molecular Sciences ◽

10.3390/ijms22105328 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5328

Author(s):

Miao Ma ◽

Margaux Lustig ◽

Michèle Salem ◽

Dominique Mengin-Lecreulx ◽

Gilles Phan ◽

...

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Cell Division ◽

Membrane Proteins ◽

Outer Membrane ◽

Efflux Pump ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Active Efflux

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.

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