Ampicillin permeation across OmpF, the major outer-membrane channel in Escherichia coli

Ghai, Ishan; Bajaj, Harsha; Bafna, Jayesh Arun; Hussein, Hussein Ali El Damrany; Winterhalter, Mathias; Wagner, Richard

doi:10.1074/jbc.ra117.000705

Cited by 38 publications

(31 citation statements)

References 46 publications

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“…The β-lactam resistance in gram-negative bacteria has been attributed not only to the presence of the hydrolyzing enzymes but also to the modification in the permeability of the outer membrane as well as to upregulation of multidrug efflux pump and alteration of antibiotic target proteins [ 11 , 87 ]. Porin loss or mutation of the porin-coding sequence decreases membrane permeability and leads to impairment of antibiotic entry [ 88 ], hence loss of porins have been associated with a carbapenem and extended-spectrum cephalosporin resistance [ 89 ].…”

Section: Discussionmentioning

confidence: 99%

β-lactam resistance associated with β-lactamase production and porin alteration in clinical isolates of E. coli and K. pneumoniae

et al. 2021

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β-lactam resistance represents a worldwide problem and a serious challenge for antimicrobial treatment. Hence this research was conducted to recognize several mechanisms mediating β-lactam resistance in E. coli and K. pneumoniae clinical isolates collected from Mansoura University hospitals, Egypt. A total of 80 isolates, 45 E. coli and 35 K. pneumoniae isolates, were collected and their antibiotic susceptibility was determined by the Disc diffusion method followed by phenotypic and genotypic detection of extended-spectrum β-lactamases (ESBLs), AmpC β-lactamase, carbapenemase enzymes. The outer membrane protein porins of all isolates were analyzed and their genes were examined using gene amplification and sequencing. Also, the resistance to complement-mediated serum killing was estimated. A significant percentage of isolates (93.8%) were multidrug resistance and showed an elevated resistance to β-lactam antibiotics. The presence of either ESBL or AmpC enzymes was high among isolates (83.75%). Also, 60% of the isolated strains were carbapenemase producers. The most frequently detected gene of ESBL among all tested isolates was blaCTX-M-15 (86.3%) followed by blaTEM-1 (81.3%) and blaSHV-1 (35%) while the Amp-C gene was present in 83.75%. For carbapenemase-producing isolates, blaNDM1 was the most common (60%) followed by blaVIM-1 (35%) and blaOXA-48 (13.8%). Besides, 73.3% and 40% of E. coli and K. pneumoniae isolates respectively were serum resistant. Outer membrane protein analysis showed that 93.3% of E. coli and 95.7% of K. pneumoniae isolates lost their porins or showed modified porins. Furthermore, sequence analysis of tested porin genes in some isolates revealed the presence of frameshift mutations that produced truncated proteins of smaller size. β-lactam resistance in K. pneumoniae and E. coli isolates in our hospitals is due to a combination of β-lactamase activity and porin loss/alteration. Hence more restrictions should be applied on β-lactams usage to decrease the emergence of resistant strains.

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Section: Discussionmentioning

confidence: 99%

β-lactam resistance associated with β-lactamase production and porin alteration in clinical isolates of E. coli and K. pneumoniae

et al. 2021

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“…(see BOX 1 for more details). A different approach involves the use of an unbalanced charge accumulation 55,56 . Creating a concentration gradient between both sides of the channel induces a concentration-driven flux (BOX 2).…”

Section: Experimental Tools To Characterize Permeation Across Porinsmentioning

confidence: 99%

Porins and small-molecule translocation across the outer membrane of Gram-negative bacteria

Vergalli¹,

Bodrenko²,

Masi³

et al. 2019

Nat Rev Microbiol

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255

260

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Gram-negative bacteria and their complex cell envelope comprising an outer and inner membrane are an important and attractive system for studying the translocation of small molecules across biological membranes. In the outer membrane of Enterobacteriaceae, trimeric porins control the cellular penetration of small molecules, including nutrients and antibacterial agents. The synergistic action between relatively slow porin-mediated passive uptake across the outer membrane and active efflux transporters in the inner membrane creates a permeability barrier that reinforces the enzymatic modification barrier, which efficiently reduces the intracellular concentrations of small molecules and contributes to the emergence of antibiotic resistance. In this review, we discuss recent advances in our understanding of the molecular and functional roles of classic porins in small molecule translocation in Enterobacteriaceae and consider the crucial role of porins in antibiotic resistance. Commented [w1]: Is this specification necessary here?, in my opinion it deviates, better to put later… Commented [JP2]: Editor request... porins represent the preferred route for the entry of β-lactams, including cephalosporins, penicillins and carbapenems 14-16. The clinical relevance of membrane-associated mechanisms (MAMs) of resistance (i.e. porin defects and/or overexpression of multidrug efflux pumps) has been well established for these antibiotics. The Influx and Efflux rates control the internal concentration of antibiotics and represent the first lane (mechanical barrier) protecting the bacterial cells against therapeutic treatment 1-3,6. Consequently, studies on bacterial porins are receiving a renewed interest due to their key role in the bacterial susceptibility towards clinically used antibiotics. In combination with the expression of antibiotic-modifying enzymes expressed in the periplasm (e.g. β-lactamases), porins play a key role in β-lactam resistance 4,17. In this review, we discuss recent advances in our understanding of the molecular and functional roles of classic porins in antibiotic translocation in Enterobacteriaceae. We explore structural aspects and the insights gained into permeation and the pore translocation process, the regulation of porin expression as well as the role of porins in the emergence of antibiotic susceptibility. Enterobacterial general porins Structural aspects The crystal structures of a general porin from Rhodobacter capsulatus 18 , the OmpF and PhoE porins from E. coli 19 and other E. coli OmpF structures including mutants 20,21 were the first to be solved. Only a limited number of other enterobacterial porin structures have been reported, i.e. E. coli OmpC, K. pneumoniae OmpK36 and Salmonella typhi OmpF 22-24. The lack of data has hindered attempts to relate structure to function. Recently, the structures of two porins from P. stuartii as well as the structures of the OmpF and OmpC orthologs of K. pneumoniae, E. aerogenes and E. cloacae have been reported 12,25,26. Another recent study reported th...

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“…8 In our recent work, we investigated the relationship between the dipole moment of the substrates and their ability to follow the sequence of steps imposed by the internal electrostatics of non-specific porins in E. coli. [9][10][11][12] However, key functional and structural differences between these porins and specific channels require a more detailed investigation to disclose the mechanisms of permeation through the OM and to define new strategies to design effective antibiotics. The presence of multiple small pore-size channels might offer alternative pathways for antibiotics penetration in Pa, as recently demonstrated for carbapenem molecules.…”

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confidence: 99%

Getting Drugs through Small Pores: Exploiting the Porins Pathway in Pseudomonas aeruginosa

et al. 2018

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Understanding molecular properties of outer membrane channels of Gram-negative bacteria is of fundamental significance as they are the entry point of polar antibiotics into bacteria. Outer membrane proteomics revealed OccK8 (OprE) to be among the five most expressed substrate specific channels of the clinically important Pseudomonas aeruginosa. The high-resolution X-ray structure and electrophysiology highlighted a very narrow pore. However, experimental in vitro methods showed the transport of natural amino acids and antibiotics, among them ceftazidime. We used molecular dynamics simulations to reveal the importance of the physicochemical properties of ceftazidime in modulating the translocation through OccK8, proposing a structure-function relationship. As in general porins, the internal electric field favors the translocation of polar molecules by gainful energy compensation in the central constriction region. Importantly, the comparatively narrow OccK8 pore can undergo a substrate-induced expansion to accommodate relatively large-sized substrates.

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Ampicillin permeation across OmpF, the major outer-membrane channel in Escherichia coli

Cited by 38 publications

References 46 publications

β-lactam resistance associated with β-lactamase production and porin alteration in clinical isolates of E. coli and K. pneumoniae

β-lactam resistance associated with β-lactamase production and porin alteration in clinical isolates of E. coli and K. pneumoniae

Porins and small-molecule translocation across the outer membrane of Gram-negative bacteria

Getting Drugs through Small Pores: Exploiting the Porins Pathway in Pseudomonas aeruginosa

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