Persister Escherichia coli Cells Have a Lower Intracellular pH than Susceptible Cells but Maintain Their pH in Response to Antibiotic Treatment

Persister and VBNC cells can phenotypically survive environmental stressors, such as antibiotic treatment, limitation of nutrients, and acid stress, and have been linked to chronic infections and antimicrobial resistance. It has recently been suggested that pH regulation might play a role in an organism’s phenotypic survival to antibiotics; however, this hypothesis remains to be tested.

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Does low intensity He-Ne laser radiation affect the intracellular pH of intact Escherichia coli cells?

10.1117/12.209924 ◽

1995 ◽

Cited By ~ 3

Author(s):

Terence I. Quickenden ◽

Lillian L. L. Daniels ◽

Lyndsay T. Byrne

Keyword(s):

Escherichia Coli ◽

Laser Radiation ◽

Intracellular Ph ◽

Low Intensity ◽

Escherichia Coli Cells

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Involvement of the ornithine decarboxylase gene in acid stress response in probiotic Lactobacillus delbrueckii UFV H2b20

Beneficial Microbes ◽

10.3920/bm2014.0122 ◽

2015 ◽

Vol 6 (5) ◽

pp. 719-725 ◽

Cited By ~ 1

Author(s):

A.B. Ferreira ◽

M.N.V. de Oliveira ◽

F.S. Freitas ◽

A.D. Paiva ◽

P. Alfenas-Zerbini ◽

...

Keyword(s):

Amino Acid ◽

Stress Response ◽

Intracellular Ph ◽

Ornithine Decarboxylase ◽

Ph Regulation ◽

Acid Stress ◽

Lactobacillus Delbrueckii ◽

Control Treatment ◽

Amino Acid Permease ◽

Acid Stress Response

Amino acid decarboxylation is important for the maintenance of intracellular pH under acid stress. This study aims to carry out phylogenetic and expression analysis by real-time PCR of two genes that encode proteins involved in ornithine decarboxylation in Lactobacillus delbrueckii UFV H2b20 exposed to acid stress. Sequencing and phylogeny analysis of genes encoding ornithine decarboxylase and amino acid permease in L. delbrueckii UFV H2b20 showed their high sequence identity (99%) and grouping with those of L. delbrueckii subsp. bulgaricus ATCC 11842. Exposure of L. delbrueckii UFV H2b20 cells in MRS pH 3.5 for 30 and 60 min caused a significant increase in expression of the gene encoding ornithine decarboxylase (up to 8.1 times higher when compared to the control treatment). Increased expression of the ornithine decarboxylase gene demonstrates its involvement in acid stress response in L. delbrueckii UFV H2b20, evidencing that the protein encoded by that gene could be involved in intracellular pH regulation. The results obtained show ornithine decarboxylation as a possible mechanism of adaptation to an acidic environmental condition, a desirable and necessary characteristic for probiotic cultures and certainly important to the survival and persistence of the L. delbrueckii UFV H2b20 in the human gastrointestinal tract.

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Putrescine as a modulator of the level of RNA polymerase σS subunit in Escherichia coli cells under acid stress

Biochemistry (Moscow) ◽

10.1134/s0006297906020118 ◽

2006 ◽

Vol 71 (2) ◽

pp. 185-193 ◽

Cited By ~ 5

Author(s):

A. G. Tkachenko ◽

M. S. Shumkov ◽

A. V. Akhova

Keyword(s):

Escherichia Coli ◽

Rna Polymerase ◽

Acid Stress ◽

Escherichia Coli Cells

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Population dynamics of Escherichia coli in the gastrointestinal tracts of Tanzanian children

10.1101/294934 ◽

2018 ◽

Author(s):

Taylor K. S. Richter ◽

Tracy H. Hazen ◽

Diana Lam ◽

Christian L. Coles ◽

Jessica C. Seidman ◽

...

Keyword(s):

Escherichia Coli ◽

Gastrointestinal Tract ◽

Antimicrobial Resistance ◽

Antibiotic Treatment ◽

Genomic Diversity ◽

Human Gastrointestinal Tract ◽

E Coli ◽

Time Points ◽

Antimicrobial Resistance Genes ◽

Variable Nature

AbstractThe stability of the Escherichia coli populations in the human gastrointestinal tract are not fully appreciated, and represent a significant knowledge gap regarding gastrointestinal community structure, as well as resistance to incoming pathogenic bacterial species and antibiotic treatment. The current study examines the genomic content of 240 Escherichia coli isolates from children 2 to 35 months old in Tanzania. The E. coli strains were isolated from three time points spanning a six month time period, with or without antibiotic treatment. The resulting isolates were sequenced, and the genomes compared. The findings in this study highlight the transient nature of E. coli strains in the gastrointestinal tract of children, as during a six-month interval, no one individual contained phylogenomically related isolates at all three time points. While the majority of the isolates at any one time point were phylogenomically similar, most individuals did not contain phylogenomically similar isolates at more than two time points. Examination of global genome content, canonical E. coli virulence factors, multilocus sequence type, serotype, and antimicrobial resistance genes identified diversity even among phylogenomically similar strains. There was no apparent increase in the antimicrobial resistance gene content after antibiotic treatment. The examination of the E. coli from longitudinal samples from multiple children in Tanzania provides insight into the genomic diversity and population variability of resident E. coli within the rapidly changing environment of the gastrointestinal tract.ImportanceThis study increases the number of resident Escherichia coli genome sequences, and explores E. coli diversity through longitudinal sampling. We investigate the genomes of E. coli isolated from human gastrointestinal tracts as part of an antibiotic treatment program among rural Tanzanian children. Phylogenomics demonstrates that resident E. coli are diverse, even within a single host. Though the E. coli isolates of the gastrointestinal community tend to be phylogenomically similar at a given time, they differed across the interrogated time points, demonstrating the variability of the members of the E. coli community. Exposure to antibiotic treatment did not have an apparent impact on the E. coli community or the presence of resistance and virulence genes within E. coli genomes. The findings of this study highlight the variable nature of bacterial members of the human gastrointestinal tract.

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Temporal Variability ofEscherichia coliDiversity in the Gastrointestinal Tracts of Tanzanian Children with and without Exposure to Antibiotics

mSphere ◽

10.1128/msphere.00558-18 ◽

2018 ◽

Vol 3 (6) ◽

Cited By ~ 9

Author(s):

Taylor K. S. Richter ◽

Tracy H. Hazen ◽

Diana Lam ◽

Christian L. Coles ◽

Jessica C. Seidman ◽

...

Keyword(s):

Escherichia Coli ◽

Gastrointestinal Tract ◽

Antimicrobial Resistance ◽

Antibiotic Treatment ◽

Genomic Diversity ◽

Human Gastrointestinal Tract ◽

Content Type ◽

E Coli ◽

Time Points ◽

Antimicrobial Resistance Genes

ABSTRACTThe stability of theEscherichia colipopulations in the human gastrointestinal tract is not fully appreciated, and represents a significant knowledge gap regarding gastrointestinal community structure, as well as resistance to incoming pathogenic bacterial species and antibiotic treatment. The current study examines the genomic content of 240Escherichia coliisolates from 30 children, aged 2 to 35 months old, in Tanzania. TheE. colistrains were isolated from three time points spanning a six-month time period, with and without antibiotic treatment. The resulting isolates were sequenced, and the genomes compared. The findings in this study highlight the transient nature ofE. colistrains in the gastrointestinal tract of these children, as during a six-month interval, no one individual contained phylogenomically related isolates at all three time points. While the majority of the isolates at any one time point were phylogenomically similar, most individuals did not contain phylogenomically similar isolates at more than two time points. Examination of global genome content, canonicalE. colivirulence factors, multilocus sequence type, serotype, and antimicrobial resistance genes identified diversity even among phylogenomically similar strains. There was no apparent increase in the antimicrobial resistance gene content after antibiotic treatment. The examination of theE. colifrom longitudinal samples from multiple children in Tanzania provides insight into the genomic diversity and population variability of residentE. coliwithin the rapidly changing environment of the gastrointestinal tract of these children.IMPORTANCEThis study increases the number of residentEscherichia coligenome sequences, and exploresE. colidiversity through longitudinal sampling. We investigate the genomes ofE. coliisolated from human gastrointestinal tracts as part of an antibiotic treatment program among rural Tanzanian children. Phylogenomics demonstrates that residentE. coliare diverse, even within a single host. Though theE. coliisolates of the gastrointestinal community tend to be phylogenomically similar at a given time, they differed across the interrogated time points, demonstrating the variability of the members of theE. colicommunity in these subjects. Exposure to antibiotic treatment did not have an apparent impact on theE. colicommunity or the presence of resistance and virulence genes withinE. coligenomes. The findings of this study highlight the variable nature of specific bacterial members of the human gastrointestinal tract.

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Importance of Glutathione for Growth and Survival of Escherichia coli Cells: Detoxification of Methylglyoxal and Maintenance of Intracellular K+

Journal of Bacteriology ◽

10.1128/jb.180.16.4314-4318.1998 ◽

1998 ◽

Vol 180 (16) ◽

pp. 4314-4318 ◽

Cited By ~ 64

Author(s):

G. P. Ferguson ◽

I. R. Booth

Keyword(s):

Escherichia Coli ◽

Intracellular Ph ◽

Parent Strain ◽

Cytoplasmic Ph ◽

Growth And Survival ◽

E Coli ◽

Enhanced Sensitivity ◽

Escherichia Coli Cells ◽

Highly Sensitive

ABSTRACT The role of the tripeptide glutathione in the growth and survival of Escherichia coli cells has been investigated. Glutathione-deficient mutants leak potassium and have a reduced cytoplasmic pH. These mutants are more sensitive to methylglyoxal than the parent strain, indicating that in the absence of glutathione-dependent detoxification, acidification of the cytoplasm cannot fully protect cells. However, increasing the intracellular pH of the glutathione-deficient strain resulted in enhanced sensitivity to methylglyoxal. This suggests that acidification of the cytoplasm can provide some protection to E. coli cells in the absence of glutathione. In the presence of the Kdp system, glutathione-deficient mutants are highly sensitive to methylglyoxal. This is due to the higher intracellular pH in these cells. In the absence of methylglyoxal, the presence of the Kdp system in a glutathione-deficient strain also leads to an extended lag upon dilution into fresh medium. These data highlight the importance of glutathione for the regulation of the K+ pool and survival of exposure to methylglyoxal.

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Changes in Clinical Characteristics of Community-Acquired Acute Pyelonephritis and Antimicrobial Resistance of Uropathogenic Escherichia coli in South Korea in the Past Decade

Antibiotics ◽

10.3390/antibiotics9090617 ◽

2020 ◽

Vol 9 (9) ◽

pp. 617

Author(s):

Ki Tae Kwon ◽

Bongyoung Kim ◽

Seong-yeol Ryu ◽

Seong-Heon Wie ◽

Jieun Kim ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

South Korea ◽

Antibiotic Treatment ◽

Acute Pyelonephritis ◽

Clinical Characteristics ◽

Total Duration ◽

Generation Cephalosporin ◽

E Coli ◽

Almost All

This study examined changes in the clinical characteristics of community-acquired acute pyelonephritis (CA-APN) in South Korea between the period 2010–2011 and 2017–2018. We recruited all CA-APN patients aged ≥19 years who visited eight hospitals in South Korea from September 2017 to August 2018, prospectively. Data collected were compared with those from the previous study in 2010–2012, with the same design and participation from 11 hospitals. A total of 617 patients were enrolled and compared to 818 patients’ data collected in 2010–2011. Escherichia coli was the most common causative pathogen of CA-APN in both periods (87.3% vs. 86.5%, p = 0.680). E. coli isolates showed significantly higher antimicrobial resistance against fluoroquinolone (32.0% vs. 21.6%, p < 0.001), cefotaxime (33.6% vs. 8.3%, p < 0.001), and trimethoprim/sulfamethoxazole (37.5% vs. 29.2%, p = 0.013) in 2017–2018 than in 2010–2011. Total duration of antibiotic treatment increased from 16.55 ± 9.68 days in 2010–2011 to 19.12 ± 9.90 days in 2017–2018 (p < 0.001); the duration of carbapenem usage increased from 0.59 ± 2.87 days in 2010–2011 to 1.79 ± 4.89 days in 2010–2011 (p < 0.001). The median hospitalization was higher for patients in 2017–2018 than in 2010–2011 (9 vs. 7 days, p < 0.001). In conclusion, antimicrobial resistance of E. coli to almost all antibiotic classes, especially third generation cephalosporin, increased significantly in CA-APN in South Korea. Consequently, total duration of antibiotic treatment, including carbapenem usage, increased.

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The Role of Integration Host Factor in Escherichia coli Persister Formation

mBio ◽

10.1128/mbio.03420-21 ◽

2022 ◽

Author(s):

Samantha E. Nicolau ◽

Kim Lewis

Keyword(s):

Escherichia Coli ◽

Treatment Failure ◽

Antibiotic Treatment ◽

Integration Host Factor ◽

Host Factor ◽

Clinical Isolates ◽

Chronic Infections

Persisters are phenotypic variants that survive exposure to antibiotics through temporary dormancy. Mutants with increased levels of persisters have been identified in clinical isolates, and evidence suggests these cells contribute to chronic infections and antibiotic treatment failure.

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