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Gourari-Bouzouina K, Boucherit-Otmani Z, Halla N, Seghir A, Baba Ahmed-Kazi Tani ZZ, Boucherit K. Exploring the dynamics of mixed-species biofilms involving Candida spp. and bacteria in cystic fibrosis. Arch Microbiol 2024; 206:255. [PMID: 38734793 DOI: 10.1007/s00203-024-03967-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/17/2024] [Indexed: 05/13/2024]
Abstract
Cystic fibrosis (CF) is an inherited disease that results from mutations in the gene responsible for the cystic fibrosis transmembrane conductance regulator (CFTR). The airways become clogged with thick, viscous mucus that traps microbes in respiratory tracts, facilitating colonization, inflammation and infection. CF is recognized as a biofilm-associated disease, it is commonly polymicrobial and can develop in biofilms. This review discusses Candida spp. and both Gram-positive and Gram-negative bacterial biofilms that affect the airways and cause pulmonary infections in the CF context, with a particular focus on mixed-species biofilms. In addition, the review explores the intricate interactions between fungal and bacterial species within these biofilms and elucidates the underlying molecular mechanisms that govern their dynamics. Moreover, the review addresses the multifaceted issue of antimicrobial resistance in the context of CF-associated biofilms. By synthesizing current knowledge and research findings, this review aims to provide insights into the pathogenesis of CF-related infections and identify potential therapeutic approaches to manage and combat these complex biofilm-mediated infections.
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Affiliation(s)
- Karima Gourari-Bouzouina
- Antibiotics Antifungal Laboratory, Physical Chemistry, Synthesis and Biological Activity (LapSab), Department of Biology, Faculty of Sciences, University of Tlemcen, BP 119, 13000, Tlemcen, Algeria.
| | - Zahia Boucherit-Otmani
- Antibiotics Antifungal Laboratory, Physical Chemistry, Synthesis and Biological Activity (LapSab), Department of Biology, Faculty of Sciences, University of Tlemcen, BP 119, 13000, Tlemcen, Algeria
| | - Noureddine Halla
- Laboratory of Biotoxicology, Pharmacognosy and Biological Recovery of Plants, Department of Biology, Faculty of Sciences, University of Moulay-Tahar, 20000, Saida, Algeria
| | - Abdelfettah Seghir
- Antibiotics Antifungal Laboratory, Physical Chemistry, Synthesis and Biological Activity (LapSab), Department of Biology, Faculty of Sciences, University of Tlemcen, BP 119, 13000, Tlemcen, Algeria
| | - Zahira Zakia Baba Ahmed-Kazi Tani
- Antibiotics Antifungal Laboratory, Physical Chemistry, Synthesis and Biological Activity (LapSab), Department of Biology, Faculty of Sciences, University of Tlemcen, BP 119, 13000, Tlemcen, Algeria
| | - Kebir Boucherit
- Antibiotics Antifungal Laboratory, Physical Chemistry, Synthesis and Biological Activity (LapSab), Department of Biology, Faculty of Sciences, University of Tlemcen, BP 119, 13000, Tlemcen, Algeria
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Neff SL, Doing G, Reiter T, Hampton TH, Greene CS, Hogan DA. Pseudomonas aeruginosa transcriptome analysis of metal restriction in ex vivo cystic fibrosis sputum. Microbiol Spectr 2024; 12:e0315723. [PMID: 38385740 PMCID: PMC10986534 DOI: 10.1128/spectrum.03157-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 01/22/2024] [Indexed: 02/23/2024] Open
Abstract
Chronic Pseudomonas aeruginosa lung infections are a feature of cystic fibrosis (CF) that many patients experience even with the advent of highly effective modulator therapies. Identifying factors that impact P. aeruginosa in the CF lung could yield novel strategies to eradicate infection or otherwise improve outcomes. To complement published P. aeruginosa studies using laboratory models or RNA isolated from sputum, we analyzed transcripts of strain PAO1 after incubation in sputum from different CF donors prior to RNA extraction. We compared PAO1 gene expression in this "spike-in" sputum model to that for P. aeruginosa grown in synthetic cystic fibrosis sputum medium to determine key genes, which are among the most differentially expressed or most highly expressed. Using the key genes, gene sets with correlated expression were determined using the gene expression analysis tool eADAGE. Gene sets were used to analyze the activity of specific pathways in P. aeruginosa grown in sputum from different individuals. Gene sets that we found to be more active in sputum showed similar activation in published data that included P. aeruginosa RNA isolated from sputum relative to corresponding in vitro reference cultures. In the ex vivo samples, P. aeruginosa had increased levels of genes related to zinc and iron acquisition which were suppressed by metal amendment of sputum. We also found a significant correlation between expression of the H1-type VI secretion system and CFTR corrector use by the sputum donor. An ex vivo sputum model or synthetic sputum medium formulation that imposes metal restriction may enhance future CF-related studies.IMPORTANCEIdentifying the gene expression programs used by Pseudomonas aeruginosa to colonize the lungs of people with cystic fibrosis (CF) will illuminate new therapeutic strategies. To capture these transcriptional programs, we cultured the common P. aeruginosa laboratory strain PAO1 in expectorated sputum from CF patient donors. Through bioinformatic analysis, we defined sets of genes that are more transcriptionally active in real CF sputum compared to a synthetic cystic fibrosis sputum medium. Many of the most differentially active gene sets contained genes related to metal acquisition, suggesting that these gene sets play an active role in scavenging for metals in the CF lung environment which may be inadequately represented in some models. Future studies of P. aeruginosa transcript abundance in CF may benefit from the use of an expectorated sputum model or media supplemented with factors that induce metal restriction.
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Affiliation(s)
- Samuel L. Neff
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Georgia Doing
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Taylor Reiter
- Department of Biomedical Informatics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Thomas H. Hampton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Casey S. Greene
- Department of Biomedical Informatics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Deborah A. Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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Soontarach R, Srimanote P, Voravuthikunchai SP, Chusri S. Antibacterial and Anti-Biofilm Efficacy of Endolysin LysAB1245 against a Panel of Important Pathogens. Pharmaceuticals (Basel) 2024; 17:155. [PMID: 38399370 PMCID: PMC10893532 DOI: 10.3390/ph17020155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 01/23/2024] [Accepted: 01/23/2024] [Indexed: 02/25/2024] Open
Abstract
Infections caused by antibiotic-resistant bacteria pose a significant global challenge. This study explores the antibacterial effects of a bacteriophage-derived endolysin, LysAB1245, against important pathogens, including Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. We determined the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) for all tested isolates. A time-kill study was conducted to evaluate the reduction in bacterial survival following treatment with LysAB1245. Additionally, the effects of LysAB1245 on P. aeruginosa K1455 and methicillin-resistant S. aureus (MRSA) NPRC 001R-formed biofilms were investigated. The MIC and MBC of LysAB1245 against all the tested isolates ranged from 4.68 to 9.36 µg/mL and 4.68 to 18.72 µg/mL, respectively. The time-kill study demonstrated more than a 4 log CFU/mL (99.99%) reduction in bacterial survival within 6 h of LysAB1245 treatment at 2MIC. LysAB1245 (1/8-1/2MIC) treatment significantly reduced biofilms formed by P. aeruginosa and MRSA in a concentration-dependent manner. Furthermore, scanning electron and confocal laser scanning microscopy confirmed the potential inhibition effects on 3-day established biofilms formed on abiotic surfaces upon treatment with LysAB1245 at 2MIC. The findings indicate that endolysin LysAB1245 could be employed as a new alternative therapeutic antibacterial and anti-biofilm agent for combating biofilm-related infections.
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Affiliation(s)
- Rosesathorn Soontarach
- Center of Antimicrobial Biomaterial Innovation-Southeast Asia, Faculty of Science, Prince of Songkla University, Songkhla 90110, Thailand; (R.S.); (S.P.V.)
- Division of Infectious Diseases, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla 90110, Thailand
| | - Potjanee Srimanote
- Graduate in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani 12121, Thailand;
| | - Supayang Piyawan Voravuthikunchai
- Center of Antimicrobial Biomaterial Innovation-Southeast Asia, Faculty of Science, Prince of Songkla University, Songkhla 90110, Thailand; (R.S.); (S.P.V.)
| | - Sarunyou Chusri
- Division of Infectious Diseases, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla 90110, Thailand
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Neff SL, Hampton TH, Koeppen K, Sarkar S, Latario CJ, Ross BD, Stanton BA. Rocket-miR, a translational launchpad for miRNA-based antimicrobial drug development. mSystems 2023; 8:e0065323. [PMID: 37975659 PMCID: PMC10734502 DOI: 10.1128/msystems.00653-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/06/2023] [Indexed: 11/19/2023] Open
Abstract
IMPORTANCE Antimicrobial-resistant infections contribute to millions of deaths worldwide every year. In particular, the group of bacteria collectively known as ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.) pathogens are of considerable medical concern due to their virulence and exceptional ability to develop antibiotic resistance. New kinds of antimicrobial therapies are urgently needed to treat patients for whom existing antibiotics are ineffective. The Rocket-miR application predicts targets of human miRNAs in bacterial and fungal pathogens, rapidly identifying candidate miRNA-based antimicrobials. The application's target audience are microbiologists that have the laboratory resources to test the application's predictions. The Rocket-miR application currently supports 24 recognized human pathogens that are relevant to numerous diseases including cystic fibrosis, chronic obstructive pulmonary disease (COPD), urinary tract infections, and pneumonia. Furthermore, the application code was designed to be easily extendible to other human pathogens that commonly cause hospital-acquired infections.
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Affiliation(s)
- Samuel L. Neff
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Thomas H. Hampton
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Katja Koeppen
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Sharanya Sarkar
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Casey J. Latario
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Benjamin D. Ross
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
| | - Bruce A. Stanton
- Department of Microbiology and Immunology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, USA
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Neff SL, Doing G, Reiter T, Hampton TH, Greene CS, Hogan DA. Analysis of Pseudomonas aeruginosa transcription in an ex vivo cystic fibrosis sputum model identifies metal restriction as a gene expression stimulus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.21.554169. [PMID: 37662412 PMCID: PMC10473638 DOI: 10.1101/2023.08.21.554169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Chronic Pseudomonas aeruginosa lung infections are a distinctive feature of cystic fibrosis (CF) pathology, that challenge adults with CF even with the advent of highly effective modulator therapies. Characterizing P. aeruginosa transcription in the CF lung and identifying factors that drive gene expression could yield novel strategies to eradicate infection or otherwise improve outcomes. To complement published P. aeruginosa gene expression studies in laboratory culture models designed to model the CF lung environment, we employed an ex vivo sputum model in which laboratory strain PAO1 was incubated in sputum from different CF donors. As part of the analysis, we compared PAO1 gene expression in this "spike-in" sputum model to that for P. aeruginosa grown in artificial sputum medium (ASM). Analyses focused on genes that were differentially expressed between sputum and ASM and genes that were most highly expressed in sputum. We present a new approach that used sets of genes with correlated expression, identified by the gene expression analysis tool eADAGE, to analyze the differential activity of pathways in P. aeruginosa grown in CF sputum from different individuals. A key characteristic of P. aeruginosa grown in expectorated CF sputum was related to zinc and iron acquisition, but this signal varied by donor sputum. In addition, a significant correlation between P. aeruginosa expression of the H1-type VI secretion system and corrector use by the sputum donor was observed. These methods may be broadly useful in looking for variable signals across clinical samples.
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Affiliation(s)
- Samuel L. Neff
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Georgia Doing
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Taylor Reiter
- Department of Biomedical Informatics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Thomas H. Hampton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Casey S. Greene
- Department of Biomedical Informatics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Deborah A. Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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Martin LW, Gray AR, Brockway B, Lamont IL. Pseudomonas aeruginosa is oxygen-deprived during infection in cystic fibrosis lungs, reducing the effectiveness of antibiotics. FEMS Microbiol Lett 2023; 370:fnad076. [PMID: 37516450 PMCID: PMC10408701 DOI: 10.1093/femsle/fnad076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 07/04/2023] [Accepted: 07/20/2023] [Indexed: 07/31/2023] Open
Abstract
Pseudomonas aeruginosa infects the lungs of patients with cystic fibrosis. Sputum expectorated from the lungs of patients contains low levels of oxygen, indicating that P. aeruginosa may be oxygen-deprived during infection. During in vitro growth under oxygen-limiting conditions, a P. aeruginosa reference strain increases expression of a cytochrome oxidase with a high affinity for oxygen, and of nitrate and nitrite reductases that enable it to use nitrate instead of oxygen during respiration. Here, we quantified transcription of the genes encoding these three enzymes in sputum samples from 18 infected patients, and in bacteria isolated from the sputum samples and grown in aerobic and anaerobic culture. In culture, expression of all three genes was increased by averages of 20- to 500-fold in anaerobically grown bacteria compared with those grown aerobically, although expression levels varied greatly between isolates. Expression of the same genes in sputum was similar to that of the corresponding bacteria in anaerobic culture. The isolated bacteria were less susceptible to tobramycin and ciprofloxacin, two widely used anti-pseudomonal antibiotics, when grown anaerobically than when grown aerobically. Our findings show that P. aeruginosa experiences oxygen starvation during infection in cystic fibrosis, reducing the effectiveness of antibiotic treatment.
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Affiliation(s)
- Lois W Martin
- Department of Biochemistry, University of Otago, Dunedin, 9016, New Zealand
| | - Andrew R Gray
- Biostatistics Centre, University of Otago, Dunedin 9016, New Zealand
| | - Ben Brockway
- Medicine, University of Otago, Dunedin 9016, New Zealand
| | - Iain L Lamont
- Department of Biochemistry, University of Otago, Dunedin, 9016, New Zealand
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Jean-Pierre V, Boudet A, Sorlin P, Menetrey Q, Chiron R, Lavigne JP, Marchandin H. Biofilm Formation by Staphylococcus aureus in the Specific Context of Cystic Fibrosis. Int J Mol Sci 2022; 24:ijms24010597. [PMID: 36614040 PMCID: PMC9820612 DOI: 10.3390/ijms24010597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/31/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen whose characteristics support its success in various clinical settings including Cystic Fibrosis (CF). In CF, S. aureus is indeed the most commonly identified opportunistic pathogen in children and the overall population. S. aureus colonization/infection, either by methicillin-susceptible or methicillin-resistant strains, will become chronic in about one third of CF patients. The persistence of S. aureus in CF patients' lungs, despite various eradication strategies, is favored by several traits in both host and pathogen. Among the latter, living in biofilm is a highly protective way to survive despite deleterious environmental conditions, and is a common characteristic shared by the main pathogens identified in CF. This is why CF has earned the status of a biofilm-associated disease for several years now. Biofilm formation by S. aureus, and the molecular mechanisms governing and regulating it, have been extensively studied but have received less attention in the specific context of CF lungs. Here, we review the current knowledge on S. aureus biofilm in this very context, i.e., the importance, study methods, molecular data published on mono- and multi-species biofilm and anti-biofilm strategies. This focus on studies including clinical isolates from CF patients shows that they are still under-represented in the literature compared with studies based on reference strains, and underlines the need for such studies. Indeed, CF clinical strains display specific characteristics that may not be extrapolated from results obtained on laboratory strains.
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Affiliation(s)
- Vincent Jean-Pierre
- HSM—HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, 34093 Montpellier, France
| | - Agathe Boudet
- VBIC—Virulence Bactérienne et Infections Chroniques, Université de Montpellier, INSERM U1047, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, 30900 Nîmes, France
| | - Pauline Sorlin
- HSM—HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, 34093 Montpellier, France
| | - Quentin Menetrey
- INFINITE—Institute for Translational Research in Inflammation, Université de Lille, INSERM U1286, CHU Lille, 59000 Lille, France
| | - Raphaël Chiron
- HSM—HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Centre de Ressources et de Compétences de la Mucoviscidose, CHU Montpellier, 34295 Montpellier, France
| | - Jean-Philippe Lavigne
- VBIC—Virulence Bactérienne et Infections Chroniques, Université de Montpellier, INSERM U1047, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, 30900 Nîmes, France
| | - Hélène Marchandin
- HSM—HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, 34093 Montpellier, France
- Correspondence:
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Distribution and Characteristics of Bacteria Isolated from Cystic Fibrosis Patients with Pulmonary Exacerbation. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2022; 2022:5831139. [PMID: 36593975 PMCID: PMC9805393 DOI: 10.1155/2022/5831139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/24/2022] [Accepted: 12/03/2022] [Indexed: 12/25/2022]
Abstract
Background Cystic fibrosis (CF) is an inherited recessive disorder characterized by recurrent and persistent pulmonary infections, resulting in lung function deterioration and early mortality. Methods A cross-sectional study was conducted on the bacterial profile and antibiotic resistance pattern of 103 respiratory specimens from CF patients with signs of pulmonary exacerbation. Antibiotic susceptibility testing and biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa isolates were performed by the Kirby-Bauer disc diffusion method and microtiter plate assay, respectively. Molecular typing of S. aureus and P. aeruginosa isolates was carried out by spa typing and repetitive extragenic palindromic element PCR. Results In a total of 129 isolates, the most prevalent organisms were S. aureus (55.3%) and P. aeruginosa (41.7%). Other less prevalent bacterial isolates include coagulase-negative staphylococci, Escherichia coli, klebsiella spp., Enterobacter spp., and Achromobacter xylosoxidans. The highest rate of resistance for S. aureus was observed to azithromycin and erythromycin (80%), ciprofloxacin (52.3%), clindamycin (44.6%) and tetracycline (43%). Twenty percent of S. aureus isolates were methicillin-resistant S. aureus (MRSA) and 47.6% were MDR S. aureus. For P. aeruginosa isolates the highest resistance was to cefepime (38.3%) and levofloxacin (33.3%) and 20% showed MDR phenotype. Conclusion Our study demonstrated a significant decline in the prevalence of P. aeruginosa infections in comparison to previous studies. We found S. aureus to be more prevalent in younger patients, whereas mucoid P. aeruginosa showed a shift in prevalence toward older ages. Molecular typing methods showed great diversity between isolates.
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Culture-dependent evaluation of the respiratory microbiome in children with cystic fibrosis. EUREKA: HEALTH SCIENCES 2022. [DOI: 10.21303/2504-5679.2022.002568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The study aimed to assess the regional peculiarities of the respiratory profile of children with cystic fibrosis (CF) in the Dnipro region (Ukraine).
Methods. Children living in the Dnipro region and aged younger than 18 years old with molecular-genetic confirmation of CF were enrolled in the study. Lung colonization was evaluated using a culture-dependent method. Sputum, mucus from the posterior pharyngeal wall and bronchoalveolar lavage fluid (BALF) were utilized.
Results. The Firmicutes phylum was the most common and occupied 54.00 % of the general proportion. On the other hand, the Proteobacteria phylum demonstrated overexpression in CF airways and kept the second rank with 28.87 %.
Sorensen's species similarity coefficient showed an allied affinity between the microbial burden of oropharyngeal samples with nasopharyngeal and sputum, QS = 0.61 and 0.91, respectively. However, the species composition within the nasal cavity was distinct from sputum and BALF (QS=0.47).
The primary pathogens in childhood were S. aureus, H. influenza, P. aeruginosa and A. fumigatus. In contrast to gram-negative non-fermenters (GNNF), the prevalence of S. aureus isolates by age had a non-linear character. The commensal microbiota changed negatively with age. Among children under 12 years, the Streptococcus genus was identified in 23.08 % of the samples, but among the age category older than 15 – only in 9.22 %.
11.06 % of S. aureus had small colony variants (SCVs) morphotypes. Isolates of P. aeruginosa with the properties of SCVs were also found in children who underwent prolonged antimicrobial treatment. However, the most prominent was the mucoid phenotype – 34.31 % of isolates.
Conclusions. Along with conventional microbiological properties, obligate pathobionts in children with CF exhibited changes, resulting in difficulties in identification. These included auxotrophic modification into SCVs and mucoid transformation.
The culture-dependent technique gives crucial data about the profile of pathogens usually associated with CF, although it is sufficiently limited
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Vincken S, Verbanck S, Hanon S, Vanderhelst E. Not a wild goose chase: long-lasting MRSA negative status following eradication therapy for chronic MRSA infection in patients with cystic fibrosis. Acta Clin Belg 2021; 77:933-937. [PMID: 34874240 DOI: 10.1080/17843286.2021.2012948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVES Prevalence of MRSA in patients with CF has risen over the past decades, and chronic infection with MRSA is associated with worse outcome in this patient group. METHODS This retrospective observational study investigated long-term eradication rate in pediatric and adult CF patients with chronic MRSA infection, using a 6-month eradication regimen containing 2 oral antibiotics, combined with topical decolonisation measures. Respiratory tract cultures were performed at least every three months, from the first MRSA-positive culture onwards. RESULTS A total of 24 patients with chronic MRSA infection were identified from our CF patient registry, of which 13 patients underwent an eradication attempt. The regimen consisted of 2 oral antibiotics: a combination of rifampicin, fusidic acid, clindamycin and co-trimoxazol, based on the sensitivity pattern of the MRSA strain. At the end of the study period (median 8.2 years), 12 out of 13 patients (92%) were MRSA negative. None of the patients interrupted treatment due to side-effects. CONCLUSIONS Eradication of chronic MRSA infection is feasible, well-tolerated and highly successful, and can offer a long-lasting MRSA-negative status, obviating the need for patient segregation.
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Affiliation(s)
- Stefanie Vincken
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Respiratory Division, Brussels, Belgium
| | - Sylvia Verbanck
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Respiratory Division, Brussels, Belgium
| | - Shane Hanon
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Respiratory Division, Brussels, Belgium
| | - Eef Vanderhelst
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Respiratory Division, Brussels, Belgium
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Boudet A, Sorlin P, Pouget C, Chiron R, Lavigne JP, Dunyach-Remy C, Marchandin H. Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics. Front Microbiol 2021; 12:750489. [PMID: 34721354 PMCID: PMC8554194 DOI: 10.3389/fmicb.2021.750489] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.
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Affiliation(s)
- Agathe Boudet
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Pauline Sorlin
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Département de Microbiologie, CHU de Nîmes, Montpellier, France
| | | | - Raphaël Chiron
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Centre de Ressources et de Compétences de la Mucoviscidose, CHU de Montpellier, Montpellier, France
| | - Jean-Philippe Lavigne
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Catherine Dunyach-Remy
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Hélène Marchandin
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Département de Microbiologie, CHU de Nîmes, Montpellier, France
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