Tricarboxylate transport in a Cit+Escherichia coli: evidence for the role of an outer membrane protein

1984 ◽  
Vol 30 (7) ◽  
pp. 916-921 ◽  
Author(s):  
Juan. M. Tomás ◽  
William W. Kay
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
E Coli ◽  
Single Carbon Source ◽  
Resistant Mutants ◽  
Induction Times ◽  
Growth Induction

A strain of Escherichia coli of bovine origin able to use tricarboxylates as single carbon source is described. Tricarboxylate utilization (Cit+) and fluorocitrate sensitivity (FCs) could be transferred conjugatively to E. coli K12 and were not plasmid borne. No evidence was found for tct gene products of Salmonella typhimurium. A citrate-inducible outer membrane protein of 21–22 kilodaltons (kd) was found only in Cit+ strains. A protein (21–22 kd) protein was also found in wild-type E. coli K12 and in fluorocitrate-resistant mutants of Cit+ strains, but it was present in a cryptic form no longer inducible by citrate. Fluorocitrate-resistant mutants of Cit+ strains were still able to transport citrate by a fuorocitrate-insensitive system. High levels of the 22-kd protein correlated with reduced growth induction times on citrate and with the ability to effectively transport citrate.

Role of outer membrane protein T in pathogenicity of avian pathogenic Escherichia coli

2017 ◽  
Vol 115 ◽  
pp. 109-116 ◽  
Author(s):  
Hassan M.A. Hejair ◽  
Jiale Ma ◽  
Yingchu Zhu ◽  
Min Sun ◽  
Wenyang Dong ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Avian Pathogenic Escherichia Coli ◽  
Pathogenic Escherichia Coli

scholarly journals NlpI Facilitates Deposition of C4bp on Escherichia coli by Blocking Classical Complement-Mediated Killing, Which Results in High-Level Bacteremia

2012 ◽  
Vol 80 (10) ◽  
pp. 3669-3678 ◽  
Author(s):  
Yu-ting Tseng ◽  
Shainn-Wei Wang ◽  
Kwang Sik Kim ◽  
Ying-Hsiang Wang ◽  
Yufeng Yao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Neonatal Meningitis ◽  
Content Type ◽  
E Coli ◽  
Classical Complement Pathway ◽  
High Level ◽  
Classical Complement

ABSTRACTNeonatal meningitisEscherichia coli(NMEC) is the most common Gram-negative organism that is associated with neonatal meningitis, which usually develops as a result of hematogenous spread of the bacteria. There are two key pathogenesis processes for NMEC to penetrate into the brain, the essential step for the development ofE. colimeningitis: a high-level bacteremia and traversal of the blood-brain barrier (BBB). Our previous study has shown that the bacterial outer membrane protein NlpI contributes to NMEC binding to and invasion of brain microvascular endothelial cells, the major component cells of the BBB, suggesting a role for NlpI in NMEC crossing of the BBB. In this study, we showed that NlpI is involved in inducing a high level of bacteremia. In addition, NlpI contributed to the recruitment of the complement regulator C4bp to the surface of NMEC to evade serum killing, which is mediated by the classical complement pathway. NlpI may be involved in the interaction between C4bp and OmpA, which is an outer membrane protein that directly interacts with C4bp on the bacterial surface. The involvement of NlpI in two key pathogenesis processes of NMEC meningitis may make this bacterial factor a potential target for prevention and therapy ofE. colimeningitis.

scholarly journals Coevolution of Bacteriophage PP01 and Escherichia coli O157:H7 in Continuous Culture

2003 ◽  
Vol 69 (1) ◽  
pp. 170-176 ◽  
Author(s):  
Katsunori Mizoguchi ◽  
Masatomo Morita ◽  
Curt R. Fischer ◽  
Masatoshi Yoichi ◽  
Yasunori Tanji ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Continuous Culture ◽  
Dilution Rate ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Escape Mutant ◽  
E Coli ◽  
Escape Mutants ◽  
Low Efficiency

ABSTRACT The interaction between Escherichia coli O157:H7 and its specific bacteriophage PP01 was investigated in chemostat continuous culture. Following the addition of bacteriophage PP01, E. coli O157:H7 cell lysis was observed by over 4 orders of magnitude at a dilution rate of 0.876 h−1 and by 3 orders of magnitude at a lower dilution rate (0.327 h−1). However, the appearance of a series of phage-resistant E. coli isolates, which showed a low efficiency of plating against bacteriophage PP01, led to an increase in the cell concentration in the culture. The colony shape, outer membrane protein expression, and lipopolysaccharide production of each escape mutant were compared. Cessation of major outer membrane protein OmpC production and alteration of lipopolysaccharide composition enabled E. coli O157:H7 to escape PP01 infection. One of the escape mutants of E. coli O157:H7 which formed a mucoid colony (Mu) on Luria-Bertani agar appeared 56 h postincubation at a dilution rate of 0.867 h−1 and persisted until the end of the experiment (∼200 h). Mu mutant cells could coexist with bacteriophage PP01 in batch culture. Concentrations of the Mu cells and bacteriophage PP01 increased together. The appearance of mutant phage, which showed a different host range among the O157:H7 escape mutants than wild-type PP01, was also detected in the chemostat culture. Thus, coevolution of phage and E. coli O157:H7 proceeded as a mutual arms race in chemostat continuous culture.

scholarly journals Cloning and Expression of the Escherichia coli K1 Outer Membrane Protein A Receptor, a gp96 Homologue

2003 ◽  
Vol 71 (4) ◽  
pp. 1680-1688 ◽  
Author(s):  
Nemani V. Prasadarao ◽  
Pramod K. Srivastava ◽  
Rajyalakshmi S. Rudrabhatla ◽  
Kwang Sik Kim ◽  
Sheng-he Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Protein A ◽  
Tumor Rejection ◽  
Cloning And Expression ◽  
Cdna Expression Library ◽  
E Coli ◽  
Outer Membrane Protein A

ABSTRACT Escherichia coli is one of the most common gram-negative bacteria that cause meningitis in neonates. Our previous studies have shown that outer membrane protein A (OmpA) of E. coli interacts with a 95-kDa human brain microvascular endothelial cell (HBMEC) glycoprotein, Ecgp, for invasion. Here, we report the identification of a gene that encodes Ecgp by screening of an HBMEC cDNA expression library as well as by 5′ rapid amplification of cDNA ends. The sequence of the Ecgp gene shows that it is highly similar to gp96, a tumor rejection antigen-1, and contains an endoplasmic reticulum retention signal, KDEL. Overexpression of either Ecgp or gp96 in both HBMECs and CHO cells increases E. coli binding and invasion. We further show that Ecgp gene-transfected HBMECs express Ecgp on the cell surface despite the presence of the KDEL motif. Northern blot analysis of total RNA from various eukaryotic cells indicates that Ecgp is significantly expressed in HBMECs. Recombinant His-tagged Ecgp blocked E. coli invasion efficiently by binding directly to the bacteria. These results suggest that OmpA of E. coli K1 interacts with a gp96-like molecule on HBMECs for invasion.

scholarly journals Immunoprotective evaluation of Escherichia coli outer membrane protein A against the main pathogens of animal mastitis

2020 ◽  
Vol 19 (1) ◽  
pp. 155-162
Author(s):  
Chen Chen ◽  
Nana Wu ◽  
Na Rong ◽  
Chao Kang ◽  
Chunlin Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Protein A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protective Function ◽  
E Coli ◽  
Ompa Protein ◽  
Outer Membrane Protein A

Purpose: To evaluate prokaryotic expression of the Escherichia coli (E. coli) outer membrane protein A (OmpA) and its immunoprotective function against the main pathogens of animal mastitis.Methods: A molecular cloning method was used to develop a prokaryotic strain expressing OmpA protein, which was purified by Ni-affinity  chromatography. Polyclonal antiserum was generated in mice immunized with OmpA protein. Enzyme-linked immunosorbent assay (ELISA) and western blotting were used to determine the titer and verify anti-OmpA serum specificity, respectively. Interaction between OmpA antiserum and main pathogens of animal mastitis was verified by ELISA and a pull-down method. The immune protective function of OmpA protein was evaluated in mice challenged with pathogens of animal mastitis. Optimal fermentation conditions to produce OmpA protein were determined by the L9(34) orthogonal test.Results: A prokaryotic strain expressing OmpA protein was developed, and purified OmpA was used to develop a mouse polyclonal antibody. The anti-OmpA serum exhibited high specificity and a titer of 1:1600. Anti-OmpA serum directly interacted with E. coli and Staphylococcus aureus (S. aureus). OmpA demonstrated a significant immune protective function of 58.33 % against E. coli and 46.15 % against S. aureus. The optimal conditions for expressing fermentation OmpA were a strain absorbance of 0.5 at a wavelength of 600 nm, IPTG final concentration of 0.3 mmol/L, induction time of 12 h, and induction temperature of 28 °C.Conclusion: OmpA possesses selective immunogenicity and a significant immune protective effect against the main pathogens of animal mastitis. The results suggest that OmpA may potentially be used as a vaccine for animal mastitis. Keywords: E. coli, OmpA protein, Immunoprotection, Animal mastitis, Protein fermentation

Isolation of FC3-11, a bacteriophage specific for theKlebsiella pneumoniaeporin OmpK36, and its use for the isolation of porin-deficient mutants

1995 ◽  
Vol 41 (4-5) ◽  
pp. 399-406 ◽  
Author(s):  
Santiago Hernández-Allés ◽  
Sebastián Albertí ◽  
Xavier Rubires ◽  
Susana Merino ◽  
Juan M. Tomás ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Resistant Mutant ◽  
Terminal Sequence ◽  
E Coli ◽  
Isolation Methods ◽  
Phage Resistant Mutant

FC3-11, a bacteriophage specific for the Klebsiella pneumoniae porin OmpK36, was isolated by its ability to infect Escherichia coli strains expressing the cloned OmpK36 porin. Porin OmpK36 was shown to be the receptor for phage FC3-11 by the observations that K. pneumoniae and E. coli strains that do not express OmpK36 were resistant to phage FC3-11, the purified porin inactivated the phage, and mutants selected for FC3-11 resistance had lost OmpK36. The outer membrane protein OmpK35 was isolated from a K. pneumoniae phage-resistant mutant by using porin isolation methods and was shown to contain an N-terminal sequence typical of enterobacterial porins. Bacteriophage FC3-11, alone or in combination with previously described lipopolysaccharide-specific phages, is a valuable tool to obtain OmpK36-porinless mutants.Key words: Klebsiella pneumoniae, porins, bacteriophage.

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