scholarly journals Cytochrome bd promotes Escherichia coli biofilm antibiotic tolerance by regulating accumulation of noxious chemicals

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Connor J. Beebout ◽  
Levy A. Sominsky ◽  
Allison R. Eberly ◽  
Gerald T. Van Horn ◽  
Maria Hadjifrangiskou
Keyword(s):  
Escherichia Coli ◽  
Quinol Oxidase ◽  
E Coli ◽  
Cytochrome Bd ◽  
External Agents ◽  
Specific Increase ◽  
Matrix Production ◽  
Noxious Chemicals ◽  
Biofilm Development ◽  
Outer Membrane Permeability

AbstractNutrient gradients in biofilms cause bacteria to organize into metabolically versatile communities capable of withstanding threats from external agents including bacteriophages, phagocytes, and antibiotics. We previously determined that oxygen availability spatially organizes respiration in uropathogenic Escherichia coli biofilms, and that the high-affinity respiratory quinol oxidase cytochrome bd is necessary for extracellular matrix production and biofilm development. In this study we investigate the physiologic consequences of cytochrome bd deficiency in biofilms and determine that loss of cytochrome bd induces a biofilm-specific increase in expression of general diffusion porins, leading to elevated outer membrane permeability. In addition, loss of cytochrome bd impedes the proton mediated efflux of noxious chemicals by diminishing respiratory flux. As a result, loss of cytochrome bd enhances cellular accumulation of noxious chemicals and increases biofilm susceptibility to antibiotics. These results identify an undescribed link between E. coli biofilm respiration and stress tolerance, while suggesting the possibility of inhibiting cytochrome bd as an antibiofilm therapeutic approach.

scholarly journals A factor produced by Escherichia coli K-12 inhibits the growth of E. coli mutants defective in the cytochrome bd quinol oxidase complex: enterochelin rediscovered

Microbiology ◽  
1998 ◽  
Vol 144 (12) ◽  
pp. 3297-3308 ◽  
Author(s):  
G. M. Cook ◽  
C. Loder ◽  
B. Soballe ◽  
G. P. Stafford ◽  
J. Membrillo-Hernandez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quinol Oxidase ◽  
E Coli ◽  
Cytochrome Bd ◽  
K 12

scholarly journals Cardiolipin enhances the enzymatic activity of cytochrome bd and cytochrome bo3 solubilized in dodecyl-maltoside

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amer H. Asseri ◽  
Albert Godoy-Hernandez ◽  
Hojjat Ghasemi Goojani ◽  
Holger Lill ◽  
Junshi Sakamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Oxygen Consumption ◽  
Integral Membrane Proteins ◽  
Terminal Oxidase ◽  
Geobacillus Thermodenitrificans ◽  
E Coli ◽  
Cytochrome Bd ◽  
Cytochrome Bo3 ◽  
Dodecyl Maltoside ◽  
Consumption Activity

AbstractCardiolipin (CL) is a lipid that is found in the membranes of bacteria and the inner membranes of mitochondria. CL can increase the activity of integral membrane proteins, in particular components of respiratory pathways. We here report that CL activated detergent-solubilized cytochrome bd, a terminal oxidase from Escherichia coli. CL enhanced the oxygen consumption activity ~ twofold and decreased the apparent KM value for ubiquinol-1 as substrate from 95 µM to 35 µM. Activation by CL was also observed for cytochrome bd from two Gram-positive species, Geobacillus thermodenitrificans and Corynebacterium glutamicum, and for cytochrome bo3 from E. coli. Taken together, CL can enhance the activity of detergent-solubilized cytochrome bd and cytochrome bo3.

scholarly journals In Escherichia coli Ammonia Inhibits Cytochrome bo3 But Activates Cytochrome bd-I

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Elena Forte ◽  
Sergey A. Siletsky ◽  
Vitaliy B. Borisov
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Dissociation Constants ◽  
Reductase Activity ◽  
Ammonia Concentration ◽  
High Concentration ◽  
E Coli ◽  
Cytochrome Bd ◽  
Cytochrome Bo3 ◽  
Oxygen Reductase

Interaction of two redox enzymes of Escherichia coli, cytochrome bo3 and cytochrome bd-I, with ammonium sulfate/ammonia at pH 7.0 and 8.3 was studied using high-resolution respirometry and absorption spectroscopy. At pH 7.0, the oxygen reductase activity of none of the enzymes is affected by the ligand. At pH 8.3, cytochrome bo3 is inhibited by the ligand, with 40% maximum inhibition at 100 mM (NH4)2SO4. In contrast, the activity of cytochrome bd-I at pH 8.3 increases with increasing the ligand concentration, the largest increase (140%) is observed at 100 mM (NH4)2SO4. In both cases, the effector molecule is apparently not NH4+ but NH3. The ligand induces changes in absorption spectra of both oxidized cytochromes at pH 8.3. The magnitude of these changes increases as ammonia concentration is increased, yielding apparent dissociation constants Kdapp of 24.3 ± 2.7 mM (NH4)2SO4 (4.9 ± 0.5 mM NH3) for the Soret region in cytochrome bo3, and 35.9 ± 7.1 and 24.6 ± 12.4 mM (NH4)2SO4 (7.2 ± 1.4 and 4.9 ± 2.5 mM NH3) for the Soret and visible regions, respectively, in cytochrome bd-I. Consistently, addition of (NH4)2SO4 to cells of the E. coli mutant containing cytochrome bd-I as the only terminal oxidase at pH 8.3 accelerates the O2 consumption rate, the highest one (140%) being at 27 mM (NH4)2SO4. We discuss possible molecular mechanisms and physiological significance of modulation of the enzymatic activities by ammonia present at high concentration in the intestines, a niche occupied by E. coli.

scholarly journals Promiscuous Cross-seeding between Bacterial Amyloids Promotes Interspecies Biofilms

2012 ◽  
Vol 287 (42) ◽  
pp. 35092-35103 ◽  
Author(s):  
Yizhou Zhou ◽  
Daniel Smith ◽  
Bryan J. Leong ◽  
Kristoffer Brännström ◽  
Fredrik Almqvist ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shewanella Oneidensis ◽  
Bacterial Attachment ◽  
Surface Attachment ◽  
E Coli ◽  
Amyloid Aggregates ◽  
Functional Amyloids ◽  
Biofilm Development ◽  
Distant Homolog

Amyloids are highly aggregated proteinaceous fibers historically associated with neurodegenerative conditions including Alzheimers, Parkinsons, and prion-based encephalopathies. Polymerization of amyloidogenic proteins into ordered fibers can be accelerated by preformed amyloid aggregates derived from the same protein in a process called seeding. Seeding of disease-associated amyloids and prions is highly specific and cross-seeding is usually limited or prevented. Here we describe the first study on the cross-seeding potential of bacterial functional amyloids. Curli are produced on the surface of many Gram-negative bacteria where they facilitate surface attachment and biofilm development. Curli fibers are composed of the major subunit CsgA and the nucleator CsgB, which templates CsgA into fibers. Our results showed that curli subunit homologs from Escherichia coli, Salmonella typhimurium LT2, and Citrobacter koseri were able to cross-seed in vitro. The polymerization of Escherichia coli CsgA was also accelerated by fibers derived from a distant homolog in Shewanella oneidensis that shares less than 30% identity in primary sequence. Cross-seeding of curli proteins was also observed in mixed colony biofilms with E. coli and S. typhimurium. CsgA was secreted from E. coli csgB− mutants assembled into fibers on adjacent S. typhimurium that presented CsgB on its surfaces. Similarly, CsgA was secreted by S. typhimurium csgB− mutants formed curli on CsgB-presenting E. coli. This interspecies curli assembly enhanced bacterial attachment to agar surfaces and supported pellicle biofilm formation. Collectively, this work suggests that the seeding specificity among curli homologs is relaxed and that heterogeneous curli fibers can facilitate multispecies biofilm development.

Sequence of Colonization Determines the Composition of Mixed Biofilms by Escherichia coli O157:H7 and O111:H8 Strains†

2015 ◽  
Vol 78 (8) ◽  
pp. 1554-1559 ◽  
Author(s):  
RONG WANG ◽  
NORASAK KALCHAYANAND ◽  
JAMES L. BONO
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Early Stage ◽  
Critical Role ◽  
The United States ◽  
Food Samples ◽  
E Coli ◽  
Cell Percentage ◽  
Composition And Structure ◽  
Biofilm Development

Bacterial biofilms are one of the potential sources of cross-contamination in food processing environments. Shiga toxin–producing Escherichia coli (STEC) O157:H7 and O111:H8 are important foodborne pathogens capable of forming biofilms, and the coexistence of these two STEC serotypes has been detected in various food samples and in multiple commercial meat plants throughout the United States. Here, we investigated how the coexistence of these two STEC serotypes and their sequence of colonization could affect bacterial growth competition and mixed biofilm development. Our data showed that E. coli O157:H7 strains were able to maintain a higher cell percentage in mixed biofilms with the co-inoculated O111:H8 companion strains, even though the results of planktonic growth competition were strain dependent. On solid surfaces with preexisting biofilms, the sequence of colonization played a critical role in determining the composition of the mixed biofilms because early stage precolonization significantly affected the competition results between the E. coli O157:H7 and O111:H8 strains. The precolonizer of either serotype was able to outgrow the other serotype in both planktonic and biofilm phases. The competitive interactions among the various STEC serotypes would determine the composition and structure of the mixed biofilms as well as their potential risks to food safety and public health, which is largely influenced by the dominant strains in the mixtures. Thus, the analysis of mixed biofilms under various conditions would be of importance to determine the nature of mixed biofilms composed of multiple microorganisms and to help implement the most effective disinfection operations accordingly.

scholarly journals The Influence of Nutrient Medium Composition on Escherichia coli Biofilm Development and Heterologous Protein Expression

2021 ◽  
Vol 11 (18) ◽  
pp. 8667
Author(s):  
Alexandra Soares ◽  
Luciana C. Gomes ◽  
Gabriel A. Monteiro ◽  
Filipe J. Mergulhão
Keyword(s):  
Escherichia Coli ◽  
Heterologous Protein ◽  
Fluorescent Protein ◽  
Culture Media ◽  
Plasmid Stability ◽  
Epifluorescence Microscopy ◽  
Egfp Expression ◽  
Heterologous Protein Expression ◽  
E Coli ◽  
Biofilm Development

In the present study, the effects of different nutrient media on the development of Escherichia coli biofilms and the production of a heterologous protein were examined. E. coli JM109(DE3) cells transformed with pFM23 plasmid carrying the gene for enhanced green fluorescent protein (eGFP) expression were used. Cells were grown in two different culture media, Lysogenic Broth (LB) and M9ZB, in a flow cell system for 10 days. Epifluorescence microscopy, fluorimetry, and a high-performance liquid chromatography (HPLC) method based on hydrophobic interaction chromatography (HIC) were used to assess bacterial growth, plasmid copy number (PCN), and eGFP production in both planktonic and biofilm cells. The results showed that biofilm development was favored in M9ZB medium when compared with LB. However, the number of eGFP-expressing cells was higher in LB for both planktonic and sessile states (two-fold and seven-fold, respectively). In addition, the PCN in biofilm cells was slightly higher when using LB medium (on average, 29 plasmids per cell versus 20 plasmids per cell in M9ZB), and higher plasmid stability was observed in biofilms formed in LB compared to their planktonic counterparts. Hence, E. coli biofilms grown in LB enhanced both plasmid stability and capacity to produce the model heterologous protein when compared to M9ZB.

scholarly journals Antibiotic Trapping by Plasmid-Encoded CMY-2 β-Lactamase Combined with Reduced Outer Membrane Permeability as a Mechanism of Carbapenem Resistance in Escherichia coli

2013 ◽  
Vol 57 (8) ◽  
pp. 3941-3949 ◽  
Author(s):  
Wil H. F. Goessens ◽  
Akke K. van der Bij ◽  
Ria van Boxtel ◽  
Johann D. D. Pitout ◽  
Peter van Ulsen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Permeability ◽  
Outer Membrane ◽  
Carbapenem Resistance ◽  
Covalent Modification ◽  
Content Type ◽  
E Coli ◽  
Outer Membrane Permeability

ABSTRACTA liver transplant patient was admitted with cholangitis, for which meropenem therapy was started. Initial cultures showed a carbapenem-susceptible (CS)Escherichia colistrain, but during admission, a carbapenem-resistant (CR)E. colistrain was isolated. Analysis of the outer membrane protein profiles showed that both CS and CRE. colilacked the porins OmpF and OmpC. Furthermore, PCR and sequence analysis revealed that both CS and CRE. colipossessedblaCTX-M-15andblaOXA-1. The CRE. colistrain additionally harboredblaCMY-2and demonstrated a >15-fold increase in β-lactamase activity against nitrocefin, but no hydrolysis of meropenem was detected. However, nitrocefin hydrolysis appeared strongly inhibited by meropenem. Furthermore, the CMY-2 enzyme demonstrated lower electrophoretic mobility after its incubation eitherin vitroorin vivowith meropenem, indicative of its covalent modification with meropenem. The presence of the acyl-enzyme complex was confirmed by mass spectrometry. By transformation of the CMY-2-encoding plasmid into variousE. colistrains, it was established that both porin deficiency and high-level expression of the enzyme were needed to confer meropenem resistance. In conclusion, carbapenem resistance emerged by a combination of elevated β-lactamase production and lack of porin expression. Due to the reduced outer membrane permeability, only small amounts of meropenem can enter the periplasm, where they are trapped but not degraded by the large amount of the β-lactamase. This study, therefore, provides evidence that the mechanism of “trapping” by CMY-2 β-lactamase plays a role in carbapenem resistance.

scholarly journals Effects of Multiple Deletions of Murein Hydrolases on Viability, Septum Cleavage, and Sensitivity to Large Toxic Molecules in Escherichia coli

2002 ◽  
Vol 184 (22) ◽  
pp. 6093-6099 ◽  
Author(s):  
Christoph Heidrich ◽  
Astrid Ursinus ◽  
Jürgen Berger ◽  
Heinz Schwarz ◽  
Joachim-Volker Höltje
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Membrane Permeability ◽  
Outer Membrane ◽  
High Molecular Weight ◽  
Macconkey Agar ◽  
Lytic Transglycosylases ◽  
E Coli ◽  
Murein Hydrolase ◽  
Outer Membrane Permeability

ABSTRACT The multiplicity of murein hydrolases found in most bacteria presents an obstacle to demonstrating the necessity of these potentially autolytic enzymes. Therefore, Escherichia coli mutants with deletions in multiple murein hydrolases, including lytic transglycosylases, amidases, and dd-endopeptidases, were constructed. Even a mutant from which seven different hydrolases were deleted was viable and grew at a normal rate. However, penicillin-induced lysis was retarded. Most of the mutants were affected in septum cleavage, which resulted in the formation of chains of cells. All three enzymes were shown to be capable of splitting the septum. Failure to cleave the septum resulted in an increase in outer membrane permeability, and thus the murein hydrolase mutants did not grow on MacConkey agar plates. In addition, the hydrolase mutants not only could be lysed by lysozyme in the absence of EDTA but also were sensitive to high-molecular-weight antibiotics, such as vancomycin and bacitracin, which are normally ineffective against E. coli.

scholarly journals Antibiotic Resistant and Biofilm-Associated Escherichia coli Isolates from Diarrheic and Healthy Dogs

2021 ◽  
Vol 9 (6) ◽  
pp. 1334
Author(s):  
Lívia Karahutová ◽  
René Mandelík ◽  
Dobroslava Bujňáková
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Companion Animals ◽  
Antibiotic Resistance Genes ◽  
Gene Encoding ◽  
E Coli ◽  
Potential Reservoir ◽  
Clinical Breakpoints ◽  
Healthy Dogs ◽  
Biofilm Development

Bacteria isolated from companion animals are attracting concerns in a view of public health including antimicrobial resistance and biofilm development, both contributing to difficult-to-treat infections. The purpose of this study was to evaluate the minimum inhibitory concentrations (MIC) of 18 antibiotics in Escherichia coli isolated from two groups of dogs (healthy and diarrheic). Isolates were classified into phylogroups, examined for the presence of resistance genes and biofilm-formation capacity. In healthy dogs, phylogenetic analysis showed that 47.37% and 34.22% of E. coli isolates belonged to commensal groups (A; B1) in contrast to diarrheic dogs; 42.2% of isolates were identified as the B2 phylogroup, and these E. coli bacteria formed a stronger biofilm. The results of healthy dogs showed higher MIC levels for tetracycline (32 mg/L), ampicillin (64 mg/L), ciprofloxacin (8 mg/L) and trimethoprim-sulphonamide (8 mg/L) compared to clinical breakpoints. The most detected gene encoding plasmid-mediated resistance to quinolones in the healthy group was qnrB, and in dogs with diarrhea, qnrS. The resistance genes were more frequently detected in healthy dogs. The presence of the integron int1 and the transposon tn3 increases the possibility of transfer of many different cassette-associated antibiotic-resistance genes. These results suggest that dogs could be a potential reservoir of resistance genes.

scholarly journals Biofilm Forming Potential of Escherichia coli from Various Sources

2020 ◽  
Vol 1 (2) ◽  
pp. 26-29
Author(s):  
Kome Otokunefor ◽  
Deborah Melex ◽  
Gideon Abu
Keyword(s):  
Escherichia Coli ◽  
Bacterial Communities ◽  
Essential Role ◽  
Clinical Isolates ◽  
E Coli ◽  
Biofilm Production ◽  
Port Harcourt ◽  
Adverse Environmental Conditions ◽  
High Level ◽  
Biofilm Development

Majority of bacterial communities exist as biofilms and these contribute to the survival of the bacteria. Biofilm development has been associated with protection from adverse environmental conditions and resistance to harmful agents. Generally, however data on biofilm-forming potential of bacteria in Nigeria is sparse. This study was therefore aimed at analyzing variations in biofilm-forming potential of Escherichia coli from various sources in Port Harcourt, Nigeria. Previously characterized clinical (30) and non-clinical (30) E. coli isolates were assessed for their biofilm-forming potential using the Congo Red agar method and variations in this potential determined as weak, moderate or strong. Majority of isolates (67%) had the potential to form biofilms but only 40% of isolates exhibiting biofilm-forming potential were from clinical sources. Isolates exhibited variable degrees of biofilm-forming potential, with only non-clinical isolates exhibiting strong potential. Majority of both clinical and non-clinical isolates (68.7% and 88% respectively) exhibited moderate biofilm-forming potential. The higher occurrence of E. coli exhibiting biofilm-forming potential among non-clinical isolates possibly reflects the essential role biofilms play in the survival of bacteria in nature, but not in infection cases. This study reports on a high level association between the isolates and biofilm production and highlights differences in the abilities of biofilm production between clinical and non-clinical isolates.  

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