Epidemiology of E. coli in Cystic Fibrosis Airways Demonstrates the Capacity for Persistent Infection but Not Patient-Patient Transmission

Abstract Background Analysis of “emerging” pathogens in cystic fibrosis (CF) lung disease has focused on unique pathogens that are rare in other human diseases or are drug resistant. Escherichia coli is recovered in the sputum of up to 25% of patients with CF, yet little is known about the epidemiology or clinical impact of infection. Methods We studied patients attending a Canadian adult CF clinic who had positive sputum cultures for E coli from 1978 to 2016. Infection was categorized as transient or persistent (≥3 positive sputum cultures, spanning >6 months). Those with persistent infection were matched 2:1 with age, sex, and time-period controls without history of E coli infection, and mixed-effects models were used to assess pulmonary exacerbation (PEx) frequency, lung function decline, hospitalization, and intravenous antibiotic days. Results Forty-five patients (12.3%) had E coli recovered from sputum samples between 1978 and 2016, and 18 patients (40%) developed persistent infection. Nine patients (24%) had PEx at incident infection, and increased bioburden was predictive of exacerbation (P = .03). Risk factors for persistent infection included lower nutritional status (P < .001) and lower lung function (P = .009), but chronic infection with Pseudomonas aeruginosa was protective. There was no difference in annual lung function decline, need for hospitalization or intravenous antibiotics, or risk of PEx in patients with persistent infection. Conclusions Persistent E coli infection was frequent and was more common in CF patients with low nutritional status and lung function. However, this does not predict clinical decline. Multicenter studies would allow better characterization of the epidemiology and clinical impact of E coli infection.

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Heat stable toxin of E. coli (STa) stimulates duodenal mucosal bicarbonate secretion in cystic fibrosis knockout mice

Gastroenterology ◽

10.1016/s0016-5085(01)80675-2 ◽

2001 ◽

Vol 120 (5) ◽

pp. A137-A137

Author(s):

D CHILDS ◽

D CROMBIE ◽

V PRATHA ◽

Z SELLERS ◽

D HOGAN ◽

...

Keyword(s):

Cystic Fibrosis ◽

Knockout Mice ◽

Bicarbonate Secretion ◽

E Coli ◽

Heat Stable

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BPI-ANCA of pediatric cystic fibrosis patients can impair BPI-mediated killing of E. coli DH5α in vitro

Pediatric Pulmonology ◽

10.1002/ppul.10416 ◽

2004 ◽

Vol 37 (2) ◽

pp. 158-164 ◽

Cited By ~ 17

Author(s):

Hendrik Schultz ◽

Susanne Schinke ◽

Katharina Mosler ◽

Karen Herlyn ◽

Antje Schuster ◽

...

Keyword(s):

Cystic Fibrosis ◽

E Coli

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Polysaccharide of a Mucoid E. coli isolated from a Patient with Cystic Fibrosis

Nature ◽

10.1038/218774b0 ◽

1968 ◽

Vol 218 (5143) ◽

pp. 774-775

Author(s):

ALFRED LINKER ◽

LEIGH R. EVANS

Keyword(s):

Cystic Fibrosis ◽

E Coli

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Cystic fibrosis pathogenesis and the role of biofilms in persistent infection

Trends in Microbiology ◽

10.1016/s0966-842x(00)01918-1 ◽

2001 ◽

Vol 9 (2) ◽

pp. 50-52 ◽

Cited By ~ 211

Author(s):

J.William Costerton

Keyword(s):

Cystic Fibrosis ◽

Persistent Infection

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Prevalence and Outcomes of Achromobacter Species Infections in Adults with Cystic Fibrosis: a North American Cohort Study

Journal of Clinical Microbiology ◽

10.1128/jcm.02556-16 ◽

2017 ◽

Vol 55 (7) ◽

pp. 2074-2085 ◽

Cited By ~ 25

Author(s):

B. D. Edwards ◽

J. Greysson-Wong ◽

R. Somayaji ◽

B. Waddell ◽

F. J. Whelan ◽

...

Keyword(s):

Cystic Fibrosis ◽

Lung Function ◽

Persistent Infection ◽

Lung Function Decline ◽

Multicenter Studies ◽

Content Type ◽

History Of ◽

Long Term Prognosis ◽

North American Cohort

ABSTRACTAchromobacterspecies are increasingly being detected in cystic fibrosis (CF) patients, with an unclear epidemiology and impact. We studied a cohort of patients attending a Canadian adult CF clinic who had positive sputum cultures forAchromobacterspecies in the period from 1984 to 2013. Infection was categorized as transient or persistent (≥50% positive cultures for 1 year). Those with persistent infection were matched 2:1 with age-, sex-, and time-matched controls without a history ofAchromobacterinfection, and mixed-effects models were used to assess pulmonary exacerbation (PEx) frequency and lung function decline. Isolates from a biobank were retrospectively assessed, identified to the species level bynrdAsequencing, and genotyped using pulsed-field gel electrophoresis (PFGE). Thirty-four patients (11% of those in our clinic), with a median age of 24 years (interquartile range [IQR], 20.3 to 29.8 years), developedAchromobacterinfection. Ten patients (29%) developed persistent infection. Persistence did not denote permanence, as most patients ultimately cleared infection, often after years. Patients were more likely to experience PEx at incident isolation than at prior or subsequent visits (odds ratio [OR], 2.7 [95% confidence interval {CI}, 1.2 to 6.7];P= 0.03). Following persistent infection, there was no difference in annual lung function decline (−1.08% [95% CI, −2.73 to 0.57%] versus −2.74% [95% CI, −4.02 to 1.46%];P= 0.12) or the odds of PEx (OR, 1.21 [95% CI, 0.45 to 3.28];P= 0.70). Differential virulence amongAchromobacterspecies was not observed, and no cases of transmission occurred. We demonstrated that incidentAchromobacterinfection was associated with a greater risk of PEx; however, neither transient nor chronic infection was associated with a worsened long-term prognosis. Large, multicenter studies are needed to clarify the clinical impact, natural history, and transmissibility ofAchromobacter.

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Insights into the Biosynthesis of Duramycin

Applied and Environmental Microbiology ◽

10.1128/aem.02698-16 ◽

2016 ◽

Vol 83 (3) ◽

Cited By ~ 16

Author(s):

Liujie Huo ◽

Ayşe Ökesli ◽

Ming Zhao ◽

Wilfred A. van der Donk

Keyword(s):

Escherichia Coli ◽

Cystic Fibrosis ◽

Viral Entry ◽

Mammalian Cells ◽

Host Cells ◽

Molecular Probe ◽

Content Type ◽

E Coli

ABSTRACT Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial peptides that are characterized by the thioether cross-linked bisamino acids lanthionine (Lan) and methyllanthionine (MeLan). Duramycin contains 19 amino acids, including one Lan and two MeLans, an unusual lysinoalanine (Lal) bridge formed from the ε-amino group of lysine 19 and a serine residue at position 6, and an erythro-3-hydroxy-l-aspartic acid at position 15. These modifications are important for the interactions of duramycin with its biological target, phosphatidylethanolamine (PE). Based on the binding affinity and specificity for PE, duramycin has been investigated as a potential therapeutic, as a molecular probe to investigate the role and localization of PE in biological systems, and to block viral entry into mammalian cells. In this study, we identified the duramycin biosynthetic gene cluster by genome sequencing of Streptomyces cinnamoneus ATCC 12686 and investigated the dur biosynthetic machinery by heterologous expression in Escherichia coli. In addition, the analog duramycin C, containing six amino acid changes compared to duramycin, was successfully generated in E. coli. The substrate recognition motif of DurX, an α-ketoglutarate/iron(II)-dependent hydroxylase that carries out the hydroxylation of aspartate 15 of the precursor peptide DurA, was also investigated using mutagenesis of the DurA peptide. Both in vivo and in vitro results demonstrated that Gly16 is important for DurX activity. IMPORTANCE Duramycin is a natural product produced by certain bacteria that binds to phosphatidylethanolamine (PE). Because PE is involved in many cellular processes, duramycin is an antibiotic that kills bacteria, but it has also been used as a molecular probe to detect PE and monitor its localization in mammalian cells and even whole organisms, and it was recently shown to display broad-spectrum inhibition of viral entry into host cells. In addition, the molecule has been evaluated as treatment for cystic fibrosis. We report here the genes that are involved in duramycin biosynthesis, and we produced duramycin by expressing those genes in Escherichia coli. We show that duramycin analogs can also be produced. The ability to access duramycin and analogs by production in E. coli opens opportunities to improve duramycin as an antibiotic, PE probe, antiviral, or cystic fibrosis therapeutic.

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Failed eradication therapy of new onset Pseudomonas aeruginosa infections in cystic fibrosis children is associated with bacterial resistance to neutrophil functions

The Journal of Infectious Diseases ◽

10.1093/infdis/jiab102 ◽

2021 ◽

Author(s):

K Kwong ◽

A Benedetti ◽

Y Yau ◽

V Waters ◽

D Nguyen

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Persistent Infection ◽

Bacterial Resistance ◽

Eradication Therapy ◽

In Vitro Assays ◽

Bacterial Killing ◽

Persistent Infections ◽

New Onset

Abstract Background Antibiotics, such as inhaled tobramycin are used to eradicate new onset Pseudomonas aeruginosa (PA) infections in cystic fibrosis (CF) patients but frequently fail due to reasons poorly understood. We hypothesized that PA isolates’ resistance to neutrophil antibacterial functions was associated with failed eradication in patients harboring those strains. Methods We analyzed all PA isolates from a cohort of 39 CF children with new onset PA infections undergoing tobramycin eradication therapy, where N=30 patients had eradicated and N=9 patients had persistent infection. We characterized several bacterial phenotypes and measured the isolates’ susceptibility to neutrophil antibacterial functions using in vitro assays of phagocytosis and intracellular bacterial killing. Results PA isolates from persistent infections were more resistant to neutrophil functions, with lower phagocytosis and intracellular bacterial killing compared to those from eradicated infections. In multivariable analyses, in vitro neutrophil responses were positively associated with twitching motility, and negatively with mucoidy. In vitro neutrophil phagocytosis was a predictor of persistent infection following tobramycin even after adjustment for clinical risk factors. Conclusions PA isolates from new onset CF infection show strain-specific susceptibility to neutrophil antibacterial functions, and infection with PA isolates resistant to neutrophil phagocytosis is an independent risk factor for failed tobramycin eradication.

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Delayed association of the NADPH oxidase complex with macrophage vacuoles containing the opportunistic pathogen Burkholderia cenocepacia

Microbiology ◽

10.1099/mic.0.026781-0 ◽

2009 ◽

Vol 155 (4) ◽

pp. 1004-1015 ◽

Cited By ~ 35

Author(s):

Karen E. Keith ◽

Daniel W. Hynes ◽

Judith E. Sholdice ◽

Miguel A. Valvano

Keyword(s):

Cystic Fibrosis ◽

Nadph Oxidase ◽

Opportunistic Pathogen ◽

Burkholderia Cenocepacia ◽

Transmembrane Conductance Regulator ◽

Macrophage Infection ◽

E Coli ◽

Transmission Electron ◽

Nadph Oxidase Complex ◽

Phagosomal Membrane

Burkholderia cenocepacia causes chronic lung infections in patients suffering from cystic fibrosis and chronic granulomatous disease. We have previously shown that B. cenocepacia survives intracellularly in macrophages within a membrane vacuole (BcCV) that delays acidification. Here, we report that after macrophage infection with live B. cenocepacia there is a ∼6 h delay in the association of NADPH oxidase with BcCVs, while heat-inactivated bacteria are normally trafficked into NADPH oxidase-positive vacuoles. BcCVs in macrophages treated with a functional inhibitor of the cystic fibrosis transmembrane conductance regulator exhibited a further delay in the assembly of the NADPH oxidase complex at the BcCV membrane, but the inhibitor did not affect NADPH oxidase complex assembly onto vacuoles containing heat-inactivated B. cenocepacia or live Escherichia coli. Macrophages produced less superoxide following B. cenocepacia infection as compared to heat-inactivated B. cenocepacia and E. coli controls. Reduced superoxide production was associated with delayed deposition of cerium perhydroxide precipitates around BcCVs of macrophages infected with live B. cenocepacia, as visualized by transmission electron microscopy. Together, our results demonstrate that intracellular B. cenocepacia resides in macrophage vacuoles displaying an altered recruitment of the NADPH oxidase complex at the phagosomal membrane. This phenomenon may contribute to preventing the efficient clearance of this opportunistic pathogen from the infected airways of susceptible patients.

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Adaptation of commensal proliferating Escherichia coli to the intestinal tract of young children with cystic fibrosis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1714373115 ◽

2018 ◽

Vol 115 (7) ◽

pp. 1605-1610 ◽

Cited By ~ 10

Author(s):

Susana Matamouros ◽

Hillary S. Hayden ◽

Kyle R. Hager ◽

Mitchell J. Brittnacher ◽

Kristina Lachance ◽

...

Keyword(s):

Escherichia Coli ◽

Cystic Fibrosis ◽

Young Children ◽

Intestinal Inflammation ◽

Growth Trait ◽

Intestinal Microbiome ◽

E Coli ◽

Fecal Fat ◽

Profile Control ◽

Fat Malabsorption

The mature human gut microbiota is established during the first years of life, and altered intestinal microbiomes have been associated with several human health disorders. Escherichia coli usually represents less than 1% of the human intestinal microbiome, whereas in cystic fibrosis (CF), greater than 50% relative abundance is common and correlates with intestinal inflammation and fecal fat malabsorption. Despite the proliferation of E. coli and other Proteobacteria in conditions involving chronic gastrointestinal tract inflammation, little is known about adaptation of specific characteristics associated with microbiota clonal expansion. We show that E. coli isolated from fecal samples of young children with CF has adapted to growth on glycerol, a major component of fecal fat. E. coli isolates from different CF patients demonstrate an increased growth rate in the presence of glycerol compared with E. coli from healthy controls, and unrelated CF E. coli strains have independently acquired this growth trait. Furthermore, CF and control E. coli isolates have differential gene expression when grown in minimal media with glycerol as the sole carbon source. While CF isolates display a growth-promoting transcriptional profile, control isolates engage stress and stationary-phase programs, which likely results in slower growth rates. Our results indicate that there is selection of unique characteristics within the microbiome of individuals with CF, which could contribute to individual disease outcomes.

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