Porins and lipopolysaccharide of Escherichia coli ATCC 25922 and isogenic rough mutants

Rivera, Mildred

doi:10.1016/0378-1097(93)90582-m

Cited by 5 publications

(7 citation statements)

References 14 publications

(16 reference statements)

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“…After 24 hours, LPS was purified and subjected to SDS-PAGE as described [51] (Figure 7). Of the LPS bands characteristic of the ATCC® 25922™ isolate [52], ciclopirox reduced the concentrations of the highest molecular weight band (∼20 kDa) as well as the O-antigen bands (37–50 kDa), as indicated by the arrows (Figure 6). LPS isolated from MG1655, which lacks an O-antigen, was unchanged in the presence of ciclopirox.…”

Section: Resultsmentioning

confidence: 94%

Toward Repurposing Ciclopirox as an Antibiotic against Drug-Resistant Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae

et al. 2013

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Antibiotic-resistant infections caused by gram-negative bacteria are a major healthcare concern. Repurposing drugs circumvents the time and money limitations associated with developing new antimicrobial agents needed to combat these antibiotic-resistant infections. Here we identified the off-patent antifungal agent, ciclopirox, as a candidate to repurpose for antibiotic use. To test the efficacy of ciclopirox against antibiotic-resistant pathogens, we used a curated collection of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae clinical isolates that are representative of known antibiotic resistance phenotypes. We found that ciclopirox, at 5–15 µg/ml concentrations, inhibited bacterial growth regardless of the antibiotic resistance status. At these same concentrations, ciclopirox reduced growth of Pseudomonas aeruginosa clinical isolates, but some of these pathogens required higher ciclopirox concentrations to completely block growth. To determine how ciclopirox inhibits bacterial growth, we performed an overexpression screen in E. coli. This screen revealed that galE, which encodes UDP-glucose 4-epimerase, rescued bacterial growth at otherwise restrictive ciclopirox concentrations. We found that ciclopirox does not inhibit epimerization of UDP-galactose by purified E. coli GalE; however, ΔgalU, ΔgalE, ΔrfaI, or ΔrfaB mutant strains all have lower ciclopirox minimum inhibitory concentrations than the parent strain. The galU, galE, rfaI, and rfaB genes all encode enzymes that use UDP-galactose or UDP-glucose for galactose metabolism and lipopolysaccharide (LPS) biosynthesis. Indeed, we found that ciclopirox altered LPS composition of an E. coli clinical isolate. Taken together, our data demonstrate that ciclopirox affects galactose metabolism and LPS biosynthesis, two pathways important for bacterial growth and virulence. The lack of any reported fungal resistance to ciclopirox in over twenty years of use in the clinic, its excellent safety profiles, novel target(s), and efficacy, make ciclopirox a promising potential antimicrobial agent to use against multidrug-resistant problematic gram-negative pathogens.

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Section: Resultsmentioning

confidence: 94%

Toward Repurposing Ciclopirox as an Antibiotic against Drug-Resistant Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae

et al. 2013

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“…Based on examples from E. coli studies , the OMP profiles of E . coli rough mutants were substantially distinct from the profiles of smooth strains [ 29 , 30 , 31 ]. In this study, differences in the OMP profiles of mutants with truncated and smooth LPS were also observed, but it seems that truncated LPS did not significantly influence the composition of the OMPs ( Figure 3 ).…”

Section: Discussionmentioning

confidence: 99%

“…Truncated LPS can affect bacterial stability and outer membrane permeability, leading to the remodeling of the structure of the outer membrane and altering the outer membrane composition of the cell wall [ 26 , 27 , 28 ]. For example, the OMP profiles of Escherichia coli rough mutants were substantially distinct from the profiles of smooth strains [ 29 , 30 , 31 ]. Live Salmonella with truncated LPS should expose more OMPs to the host immune system, but live Salmonella with deep rough LPS was unable to colonize and persist in the host organs and induced poor immunogenicity against OMPs [ 26 ].…”

Section: Introductionmentioning

confidence: 99%

Immunogenicity and Cross-Protective Efficacy Induced by Outer Membrane Proteins from Salmonella Typhimurium Mutants with Truncated LPS in Mice

Liu

Zhao

et al. 2016

IJMS

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Lipopolysaccharide (LPS) is a major virulence factor present in the outer membrane of Salmonella enterica serovar Typhimurium (S. Typhimurium). Outer membrane proteins (OMPs) from Salmonella show high immunogenicity and provide protection against Salmonella infection, and truncated LPS alters the outer membrane composition of the cell wall. In our previous study, we demonstrated that Salmonella mutants carrying truncated LPS failed to induce strong immune responses and cross-reaction to other enteric bacteria, due to their high attenuation and low colonization in the host. Therefore, we plan to investigate whether outer membrane proteins from Salmonella mutants with truncated LPS resulting from a series of nonpolar mutations, including ∆waaC12, ∆waaF15, ∆waaG42, ∆rfaH49, ∆waaI43, ∆waaJ44, ∆waaL46, ∆wbaP45 and ∆wzy-48, affect immunogenicity and provide protection against diverse Salmonella challenge. In this study, the immunogenicity and cross-protection efficiency of purified OMPs from all mutants were investigated to explore a potential OMP vaccine to protect against homologous or heterologous serotype Salmonella challenge. The results demonstrated that OMPs from three Salmonella mutants (∆waaC12, ∆waaJ44 and ∆waaL46) induced higher immune responses and provided good protection against homologous S. Typhimurium. The OMPs from these three mutants were also selected to determine the cross-protective efficacy against homologous and heterologous serotype Salmonella. Our results indicated that the mutant ∆waaC12 can elicit higher cross-reactivity and can provide good protection against S. Choleraesuis and S. Enteritidis infection and that the cross-reactivity may be ascribed to an antigen of approximately 18.4–30 kDa.

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“…It is present in the outer leaflet of the outer membrane where it tightly interacts with porins and other outer membrane proteins (OMP) that determine the permeability of the envelope (Nikaido and Vaara, 1985;1987). A number of studies involving rough LPS mutants have demonstrated the importance of this component for the structural and functional integrity of the outer membrane and for bacterial virulence (Sukupolvi and Vaara, 1989;Marvin et al, 1989;Ried et al, 1990;Rivera et al, 1993;Vaara, 1993;Stanley et al, 1993;Laird et al, 1994;Fralick and Burns-Keliher, 1994;Sandlin et al, 1995;Schwan et al, 1995). Conversely, we show herein that the co-expression of two complete LPS cores (R1 plus endogeneous core) in recombinant V. cholerae may lead to impaired cell growth and division capability, as revealed by the high proportion of cell chains or filaments observed with strains carrying the r fa R1 genetic locus.…”

Section: Discussionmentioning

confidence: 99%

Expression of Shigella sonnei lipopolysaccharide in Vibrio cholerae

Viret

Cryz

Favre

1996

Molecular Microbiology

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Making use of a newly designed mobilizable suicide vector, the genetic determinants encoding Shigella sonnei lipopolysaccharide (LPS) were stably integrated into the chromosome of the live attenuated Vibrio cholerae vaccine strain CVD103-HgR. Expression studies showed that the production of complete S. sonnei O-polysaccharide (O-PS)-bearing LPS was limited in bivalent recombinant strains that were also proficient in the synthesis of the host-encoded Inaba O-PS. Conversely, high amounts of LPS carrying S. sonnei O-PS are produced in monovalent Inaba-deficient derivatives, even in those strains which do not co-express the compatible R1 LPS core. Thus, the non-enterobacterial V. cholerae LPS core efficiently acts as a receptor for covalent binding of S. sonnei O-PS provided that competition with the host O-PS is avoided. Expression of the R1 core interferes with cell division in recombinant V. cholerae without affecting other physiological properties of vaccine strain CVD103-HgR. Both monovalent and bivalent strains stimulated high serum-antibody titres specific for their respective O-serotype(s) when administered to rabbits. The potential of V. cholerae as an expression carrier for heterologous O-serotypes is discussed.

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Porins and lipopolysaccharide of Escherichia coli ATCC 25922 and isogenic rough mutants

Cited by 5 publications

References 14 publications

Toward Repurposing Ciclopirox as an Antibiotic against Drug-Resistant Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae

Toward Repurposing Ciclopirox as an Antibiotic against Drug-Resistant Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae

Immunogenicity and Cross-Protective Efficacy Induced by Outer Membrane Proteins from Salmonella Typhimurium Mutants with Truncated LPS in Mice

Expression of Shigella sonnei lipopolysaccharide in Vibrio cholerae

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