1
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San Mauro AJS, Høiby N, Ciofu O. Increased susceptibility to azithromycin of Pseudomonas aeruginosa biofilms using RPMI 1640 testing media. APMIS 2024. [PMID: 38622982 DOI: 10.1111/apm.13413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 03/20/2024] [Indexed: 04/17/2024]
Abstract
Azithromycin (AZM) is efficient for treatment of chronic Pseudomonas aeruginosa biofilm lung infections, despite of resistance in conventional susceptibility testing. It has been shown that planktonic P. aeruginosa are more susceptible to AZM when tested in RPMI 1640 medium. The aim of the study was to test the susceptibility to AZM of P. aeruginosa biofilms in LB vs RPMI 1640 media. We investigated the effect of AZM on planktonic and biofilms of (WT) P. aeruginosa (PAO1), the hypermutable (ΔmutS) and the antibiotic-resistant phenotype(ΔnfxB) mutants. The effect of AZM on young and mature biofilms was investigated in the modified Calgary Biofilm Device by estimation of the minimal biofilm inhibitory concentration (MBIC). The AZM MBIC90 in LB/RPMI1640 on young biofilms treated for 24 h was 16/4 μg/mL for PAO1, 32/8 μg/mL for ΔmutS, and 256/16 μg/mL for ΔnfxB, while in mature biofilms was 256/2 μg/mL for PAO1 and ΔmutS and 16/1 μg/mL for ΔnfxB. The effect of AZM was improved when the treatment was prolonged to 72 h, supporting the intracellular accumulation of AZM. An increased susceptibility of P. aeruginosa biofilms to AZM was observed in RPMI 1640 than in LB medium. Our results might improve susceptibility testing and dosing of AZM for treatment of biofilm infections.
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Affiliation(s)
| | - Niels Høiby
- Institute of Immunology & Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Oana Ciofu
- Institute of Immunology & Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
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2
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Høiby N, Moser C, Ciofu O. The microenvironment in antibiotic susceptibility testing. APMIS 2024. [PMID: 38565324 DOI: 10.1111/apm.13405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/08/2024] [Indexed: 04/04/2024]
Abstract
Antibiotic susceptibility testing (AST) by agar diffusion has been repeatedly standardized and, in most cases, gives results which predict clinical success when antibiotic treatment is based on such results. The formation of the inhibition zone is due to a transition from planktonic to biofilm mode of growth. The kinetics of the interaction of antibiotics with bacteria is similar during AST by agar diffusion and during administration of antibiotics to the patients. However, the Mueller-Hinton agar (MHA) recommended for AST agar diffusion test is fundamentally different from the composition of the interstitial fluid in the human body where the infections take place and human cells do not thrive in MH media. Use of RPMI 1640 medium designed for growth of eucaryotic cells for AST of Pseudomonas aeruginosa against azithromycin results in lower minimal inhibitory concentration, compared to results obtained by MHA. The reason is that the RPMI 1640 medium increases uptake and reduces efflux of azithromycin compared to MHA. During treatment of cystic fibrosis patients with azithromycin, mutational resistance occur which is not detected by AST with MHA. Whether this is the case with other antibiotics and bacteria is not known but it is of clinical importance to be studied.
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Affiliation(s)
- Niels Høiby
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Claus Moser
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Oana Ciofu
- Institute of Immunology and Microbiology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
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3
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Tesfaye S, Asres K, Guenther S, Singh PP. Anti-malarial effect of a combination of risedronate and azithromycin against Plasmodium yoelii nigeriensis infection in Swiss mice. Parasitol Int 2022; 91:102655. [PMID: 36029959 DOI: 10.1016/j.parint.2022.102655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 11/25/2022]
Abstract
Combination therapy is used to retard the selection of malaria parasite strains resistant to individual components of a combination of drugs. This approach has proved to be a success in the combination of sulphadoxine and pyrimethamine, which targets two different steps in the folate pathway of malaria parasites. However, after the success of this therapeutic combination, the efficacy of other combinations of drugs that target different enzymes in a particular metabolic pathway has, apparently, not been reported. In the current study, the antimalarial effect of a combination of risedronate (RIS), which is known for its anti-osteoporosis activity, and azithromycin (AZT) was investigated. Peter's suppression test was carried out on mice infected with 1 × 107P. yoelii infected erythrocytes. Drug efficacy was analyzed by comparing the percent reduction in parasitaemia on day 4 post-infection. RIS was observed to be a blood schizonticidal agent against P. yoelii infection which showed ED50 7.0 (4.04-12.13) mg/kg/day x 4. Normalized isobologram showed additive action between RIS 1 mg/kg/day x 4 and AZT 10 mg/kg/day x 4, and antagonistic action for the rest of the combinations (RIS 1 + AZT 20, RIS 1 + AZT 40, RIS 5 + AZT 10, RIS 5 + AZT 20, RIS 5 + AZT 40, RIS 10 + AZT 10, RIS 10 + AZT 20 and RIS 10 + AZT 40 mg/kg/day x 4). Furthermore, a combination of RIS with AZT showed inferior efficacy as compared to AZT treatment alone. This antagonistic interaction may be due to the high accumulation of AZT in WBCs, which will reduce its serum bio-availability, whereas RIS has anti-parasitic activity by increasing WBCs.
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Affiliation(s)
- Solomon Tesfaye
- Institute of Pharmacy, Department of Pharmaceutical Biology, University of Greifswald, 17491 Greifswald, Germany; School of Pharmacy, College of Health Sciences, Addis Ababa University, Churchill Street, 1176 Addis Ababa, Ethiopia.
| | - Kaleab Asres
- School of Pharmacy, College of Health Sciences, Addis Ababa University, Churchill Street, 1176 Addis Ababa, Ethiopia
| | - Sebastian Guenther
- Institute of Pharmacy, Department of Pharmaceutical Biology, University of Greifswald, 17491 Greifswald, Germany
| | - Prati Pal Singh
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, 160062 Mohali, India
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4
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Tron C, Belleguic C, Piau C, Brinchault G, Deneuville E, Ricordel C, Kayal S, Bellissant E, Verdier MC, Lemaitre F. Determination of amoxicillin and cotrimoxazole concentrations in sputum of patients with cystic fibrosis. Biomed Chromatogr 2021; 35:e5208. [PMID: 34212399 DOI: 10.1002/bmc.5208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 06/19/2021] [Accepted: 06/28/2021] [Indexed: 11/09/2022]
Abstract
In the management of cystic fibrosis, treatments against Staphylococcus aureus and Haemophilus influenzae such as amoxicillin or cotrimoxazole have to be prescribed and the antibiotherapy's efficacy may be linked to the concentration that reaches the infected site. As cystic fibrosis patients present disturbed pharmacokinetics parameters, drug monitoring would be relevant to assess the lung distribution of antibiotics and to optimize dosing regimens. In this context, the aim of the study was to develop and validate HPLC-based methods for the determination of both antibiotics in bronchial sputum from cystic fibrosis patients, in order to assess the distribution of the drugs into the lungs. Plasma proteins were precipitated by acetonitrile and amoxicillin concentrations in sputum were determined by HPLC coupled with tandem-mass spectrometry. Following liquid extraction with ethyl acetate, cotrimoxazole was quantified by HPLC using ultraviolet detection. Both methods were rapid, specific, accurate and reproducible. The method was applied to patient samples. In three treated patients, concentrations of amoxicillin in sputum were similar and below the lower limit of quantification (0.1 μg/g) and in six patients, sputum concentrations up to 11.1 and 6.4 μg/g were measured for sulfamethoxazole and trimethoprim, respectively.
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Affiliation(s)
- Camille Tron
- Université Rennes, CHU Rennes, Inserm, EHESP, Institut de recherche en santé, environnement et travail - UM_SR, Rennes, France
| | - Chantal Belleguic
- Centre Hospitalier Universitaire de Rennes, Centre de Ressource et de Compétences de la Mucoviscidose, Rennes, France
| | - Caroline Piau
- Bacteriology-Hygiene Unit, Rennes university hospital, Rennes, France
| | - Graziella Brinchault
- Centre Hospitalier Universitaire de Rennes, Centre de Ressource et de Compétences de la Mucoviscidose, Rennes, France
| | - Eric Deneuville
- Centre Hospitalier Universitaire de Rennes, Centre de Ressource et de Compétences de la Mucoviscidose, Rennes, France
| | - Charles Ricordel
- Centre Hospitalier Universitaire de Rennes, Centre de Ressource et de Compétences de la Mucoviscidose, Rennes, France
| | - Samer Kayal
- Bacteriology-Hygiene Unit, Rennes university hospital, Rennes, France
| | - Eric Bellissant
- Université Rennes, CHU Rennes, Inserm, EHESP, Institut de recherche en santé, environnement et travail - UM_SR, Rennes, France
| | - Marie-Clémence Verdier
- Université Rennes, CHU Rennes, Inserm, EHESP, Institut de recherche en santé, environnement et travail - UM_SR, Rennes, France
| | - Florian Lemaitre
- Université Rennes, CHU Rennes, Inserm, EHESP, Institut de recherche en santé, environnement et travail - UM_SR, Rennes, France
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5
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Thomsen K, Kobayashi O, Kishi K, Shirai R, Østrup Jensen P, Heydorn A, Hentzer M, Calum H, Christophersen L, Høiby N, Moser C. Animal models of chronic and recurrent Pseudomonas aeruginosa lung infection: significance of macrolide treatment. APMIS 2021; 130:458-476. [PMID: 34117660 DOI: 10.1111/apm.13161] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/01/2021] [Accepted: 06/07/2021] [Indexed: 11/28/2022]
Abstract
Animal models of human diseases are invaluable and inevitable elements in identifying and testing novel treatments for serious diseases, including severe infections. Planning and conducting investigator-initiated human trials are generally accepted as being enormously challenging. In contrast, it is often underestimated how much planning, including background and modifying experiments, is needed to establish a relevant infectious disease animal model. However, representative animal infectious models, well designed to test generated hypotheses, are useful to improve our understanding of pathogenesis, virulence factors and host response and to identify novel treatment candidates and therapeutic strategies. Such results can subsequently proceed to clinical testing if suitable. The present review aims at presenting all the pulmonary Pseudomonas aeruginosa infectious models we have knowledge of and the detailed descriptions of established animal models in our laboratory focusing on macrolide therapy are presented.
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Affiliation(s)
- Kim Thomsen
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Osamu Kobayashi
- Department of Infectious Diseases, National Cancer Center Hospital, Tokyo, Japan
| | - Kenji Kishi
- Oitaken Kouseiren Tsurumi Hospital, Tsurumi, Beppu City, Japan
| | - Ryo Shirai
- Department of Internal Medicine, Kawasaki Medical School, General Medical Center, Okayama, Japan
| | - Peter Østrup Jensen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Arne Heydorn
- Department of Endocrinology and Nephrology, Nordsjaellands Hospital, Hillerød, Denmark
| | - Morten Hentzer
- Department of Molecular Pharmacology, H. Lundbeck A/S, Copenhagen, Denmark
| | - Henrik Calum
- Department of Clinical Microbiology, Hvidovre Hospital, Copenhagen University Hospital, Copenhagen, Denmark
| | - Lars Christophersen
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Niels Høiby
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Claus Moser
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
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6
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Burke A, Smith D, Coulter C, Bell SC, Thomson R, Roberts JA. Clinical Pharmacokinetic and Pharmacodynamic Considerations in the Drug Treatment of Non-Tuberculous Mycobacteria in Cystic Fibrosis. Clin Pharmacokinet 2021; 60:1081-1102. [PMID: 33982266 DOI: 10.1007/s40262-021-01010-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2021] [Indexed: 10/21/2022]
Abstract
Non-tuberculous mycobacteria (NTM) are an emerging group of pulmonary infectious pathogens of increasing importance to the management of patients with cystic fibrosis (CF). NTM include slow-growing mycobacteria such as Mycobacterium avium complex (MAC) and rapidly growing mycobacteria such as Mycobacterium abscessus. The incidence of NTM in the CF population is increasing and infection contributes to significant morbidity to the patient and costs to the health system. Treating M. abscessus requires the combination of multiple costly antibiotics for months, with potentially significant toxicity associated with treatment. Although international guidelines for the treatment of NTM infection in CF are available, there are a lack of robust pharmacokinetic studies in CF patients to inform dosing and drug choice. This paper aims to outline the pharmacokinetic and pharmacodynamic factors informing the optimal treatment of NTM infections in CF.
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Affiliation(s)
- Andrew Burke
- Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland School of Medicine, Brisbane, QLD, Australia
| | - Daniel Smith
- Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland School of Medicine, Brisbane, QLD, Australia
| | - Chris Coulter
- Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland School of Medicine, Brisbane, QLD, Australia
| | - Scott C Bell
- Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland School of Medicine, Brisbane, QLD, Australia.,QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Rachel Thomson
- Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland School of Medicine, Brisbane, QLD, Australia.,Immunology Department, Gallipoli Medical Research Institute, Brisbane, QLD, Australia
| | - Jason A Roberts
- Faculty of Medicine, University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia. .,Department of Pharmacy, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia. .,Department of Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia. .,Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France.
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7
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Pharmacokinetic and Pharmacodynamic Optimization of Antibiotic Therapy in Cystic Fibrosis Patients: Current Evidences, Gaps in Knowledge and Future Directions. Clin Pharmacokinet 2021; 60:409-445. [PMID: 33486720 DOI: 10.1007/s40262-020-00981-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2020] [Indexed: 10/22/2022]
Abstract
Antibiotic therapy is one of the main treatments for cystic fibrosis (CF). It aims to eradicate bacteria during early infection, calms down the inflammatory process, and leads to symptom resolution of pulmonary exacerbations. CF can modify both the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of antibiotics, therefore specific PK/PD endpoints should be determined in the context of CF. Currently available data suggest that optimal PK/PD targets cannot be attained in sputum with intravenous aminoglycosides. Continuous infusion appears preferable for β-lactam antibiotics, but optimal concentrations in sputum are unlikely to be reached, with some possible exceptions such as meropenem and ceftolozane. Usual doses are likely suboptimal for fluoroquinolones and linezolid, whereas daily doses of 45-60 mg/kg and 200 mg could be convenient for vancomycin and doxycycline, respectively. Weekly azithromycin doses of 22-30 mg/kg could also be appropriate for its anti-inflammatory effect. The difficulty with achieving optimal concentrations supports the use of combined treatments and the inhaled administration route, as very high local concentrations, concomitantly with low systemic exposure, can be obtained with the inhaled route for aminoglycosides, colistin, and fluoroquinolones, thus minimizing the risk of toxicity.
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8
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Thomsen K, Christophersen L, Lerche CJ, Holmgaard DB, Calum H, Høiby N, Moser C. Azithromycin potentiates avian IgY effect against Pseudomonas aeruginosa in a murine pulmonary infection model. Int J Antimicrob Agents 2020; 57:106213. [PMID: 33256950 DOI: 10.1016/j.ijantimicag.2020.106213] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 10/13/2020] [Accepted: 10/17/2020] [Indexed: 01/25/2023]
Abstract
Cystic fibrosis (CF) patients are at risk of acquiring chronic Pseudomonas aeruginosa lung infections. The biofilm mode of growth of P. aeruginosa induces tolerance to antibiotics and the host response; accordingly, treatment failure occurs. Supplemental azithromycin has proven beneficial in CF owing to potential immunomodulatory mechanisms. Clinical studies have demonstrated a reduction in exacerbations in CF patients by avian IgY anti-Pseudomonas immunotherapy. We hypothesise that azithromycin pre-treatment could potentiate the observed anti-Pseudomonas effect of IgY opsonisation in vivo. Evaluation of phagocytic cell capacity was performed using in vitro exposure of azithromycin pre-treated human polymorphonuclear neutrophils to IgY opsonised P. aeruginosa PAO3. A murine lung infection model using nasal planktonic P. aeruginosa inoculation and successive evaluation 24 h post-infection was used to determine lung bacteriology and subsequent pulmonary inflammation. Combined azithromycin treatment and IgY opsonisation significantly increased bacterial killing compared with the two single-treated groups and controls. In vivo, significantly increased bacterial pulmonary elimination was revealed by combining azithromycin and IgY. A reduction in the inflammatory markers mobiliser granulocyte colony-stimulating factor (G-CSF), macrophage inflammatory protein 2 (MIP-2) and interleukin 1 beta (IL-1β) paralleled this effect. Combination of azithromycin and anti-Pseudomonas IgY potentiated the killing and pulmonary elimination of P. aeruginosa in vitro and in vivo. The augmented effect of combinatory treatment with azithromycin and IgY constitutes a potential clinical application for improving anti-Pseudomonas strategies.
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Affiliation(s)
- Kim Thomsen
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Henrik Harpestrengsvej 4A, 2100-DK Copenhagen, Denmark.
| | - Lars Christophersen
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Henrik Harpestrengsvej 4A, 2100-DK Copenhagen, Denmark
| | - Christian Johann Lerche
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Henrik Harpestrengsvej 4A, 2100-DK Copenhagen, Denmark
| | | | - Henrik Calum
- Department of Clinical Microbiology, Hvidovre Hospital, Copenhagen, Denmark
| | - Niels Høiby
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Henrik Harpestrengsvej 4A, 2100-DK Copenhagen, Denmark; Institute of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claus Moser
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Henrik Harpestrengsvej 4A, 2100-DK Copenhagen, Denmark
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9
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Seinen J, Dieperink W, Mekonnen SA, Lisotto P, Harmsen HJM, Hiemstra B, Ott A, Schultz D, Lalk M, Oswald S, Hammerschmidt S, de Smet AMGA, van Dijl JM. Heterogeneous antimicrobial activity in broncho-alveolar aspirates from mechanically ventilated intensive care unit patients. Virulence 2020; 10:879-891. [PMID: 31662033 PMCID: PMC6844299 DOI: 10.1080/21505594.2019.1682797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Pneumonia is an infection of the lungs, where the alveoli in the affected area are filled with pus and fluid. Although ventilated patients are at risk, not all ventilated patients develop pneumonia. This suggests that the sputum environment may possess antimicrobial activities. Despite the generally acknowledged importance of antimicrobial activity in protecting the human lung against infections, this has not been systematically assessed to date. Therefore, the objective of the present study was to measure antimicrobial activity in broncho-alveolar aspirate (‘sputum”) samples from patients in an intensive care unit (ICU) and to correlate the detected antimicrobial activity with antibiotic levels, the sputum microbiome, and the respective patients’ characteristics. To this end, clinical metadata and sputum were collected from 53 mechanically ventilated ICU patients. The antimicrobial activity of sputum samples was tested against Streptococcus pneumoniae, Staphylococcus aureus and Streptococcus anginosus. Here we show that sputa collected from different patients presented a high degree of variation in antimicrobial activity, which can be partially attributed to antibiotic therapy. The sputum microbiome, although potentially capable of producing antimicrobial agents, seemed to contribute in a minor way, if any, to the antimicrobial activity of sputum. Remarkably, despite its potentially protective effect, the level of antimicrobial activity in the investigated sputa correlated inversely with patient outcome, most likely because disease severity outweighed the beneficial antimicrobial activities.
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Affiliation(s)
- Jolien Seinen
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Willem Dieperink
- Department of Critical Care, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Solomon A Mekonnen
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University Medicine of Greifswald, Greifswald, Germany
| | - Paola Lisotto
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Hermie J M Harmsen
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Bart Hiemstra
- Department of Critical Care, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Alewijn Ott
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department of Medical Microbiology, Certe, Groningen, The Netherlands
| | - Daniel Schultz
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Michael Lalk
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Stefan Oswald
- Department of Clinical Pharmacology, University Medicine of Greifswald, Greifswald, Germany
| | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Anne Marie G A de Smet
- Department of Critical Care, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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10
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Pseudomonas aeruginosa Magnesium Transporter MgtE Inhibits Type III Secretion System Gene Expression by Stimulating rsmYZ Transcription. J Bacteriol 2017; 199:JB.00268-17. [PMID: 28847924 DOI: 10.1128/jb.00268-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 08/23/2017] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa causes numerous acute and chronic opportunistic infections in humans. One of its most formidable weapons is a type III secretion system (T3SS), which injects powerful toxins directly into host cells. The toxins lead to cell dysfunction and, ultimately, cell death. Identification of regulatory pathways that control T3SS gene expression may lead to the discovery of novel therapeutics to treat P. aeruginosa infections. In a previous study, we found that expression of the magnesium transporter gene mgtE inhibits T3SS gene transcription. MgtE-dependent inhibition appeared to interfere with the synthesis or function of the master T3SS transcriptional activator ExsA, although the exact mechanism was unclear. We now demonstrate that mgtE expression acts through the GacAS two-component system to activate rsmY and rsmZ transcription. This event ultimately leads to inhibition of exsA translation. This inhibitory effect is specific to exsA as translation of other genes in the exsCEBA operon is not inhibited by mgtE Moreover, our data reveal that MgtE acts solely through this pathway to regulate T3SS gene transcription. Our study reveals an important mechanism that may allow P. aeruginosa to fine-tune T3SS activity in response to certain environmental stimuli.IMPORTANCE The type III secretion system (T3SS) is a critical virulence factor utilized by numerous Gram-negative bacteria, including Pseudomonas aeruginosa, to intoxicate and kill host cells. Elucidating T3SS regulatory mechanisms may uncover targets for novel anti-P. aeruginosa therapeutics and provide deeper understanding of bacterial pathogenesis. We previously found that the magnesium transporter MgtE inhibits T3SS gene transcription in P. aeruginosa In this study, we describe the mechanism of MgtE-dependent inhibition of the T3SS. Our report also illustrates how MgtE might respond to environmental cues, such as magnesium levels, to fine-tune T3SS gene expression.
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11
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Qin YH, Jiao HS, Li AS, Jiao Y, Wei LM, Zhang J, Zhong L, Liu K, Zhang XF. Transdermal application of azithromycin-amlodipine-heparin gel enhances survival of infected random ischaemic flap. J Plast Surg Hand Surg 2015; 49:319-26. [DOI: 10.3109/2000656x.2015.1042386] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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12
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Sampson MR, Dumitrescu TP, Brouwer KLR, Schmith VD. Population pharmacokinetics of azithromycin in whole blood, peripheral blood mononuclear cells, and polymorphonuclear cells in healthy adults. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2014; 3:e103. [PMID: 24599342 PMCID: PMC4039392 DOI: 10.1038/psp.2013.80] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 12/26/2013] [Indexed: 01/13/2023]
Abstract
Azithromycin's extensive distribution to proinflammatory cells, including peripheral blood mononuclear cells (PBMCs) and polymorphonuclear cells (PMNs), may be important to its antimicrobial and anti-inflammatory properties. The need to simultaneously predict azithromycin concentrations in whole blood ("blood"), PBMCs, and PMNs motivated this investigation. A single-dose study in 20 healthy adults was conducted, and nonlinear mixed effects modeling was used to simultaneously describe azithromycin concentrations in blood, PBMCs, and PMNs (simultaneous PK model). Data were well described by a four-compartment mamillary model. Apparent central clearance and volume of distribution estimates were 67.3 l/hour and 336 l (interindividual variability of 114 and 122%, respectively). Bootstrapping and visual predictive checks showed adequate model performance. Azithromycin concentrations in blood, PBMCs, and PMNs from external studies of healthy adults and cystic fibrosis patients were within the 5th and 95th percentiles of model simulations. This novel empirical model can be used to predict azithromycin concentrations in blood, PBMCs, and PMNs with different dosing regimens.
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Affiliation(s)
- M R Sampson
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA
| | - T P Dumitrescu
- 1] Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA [2] Clinical Pharmacology Modeling and Simulation, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - K L R Brouwer
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA
| | - V D Schmith
- Clinical Pharmacology Modeling and Simulation, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
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Redelman CV, Chakravarty S, Anderson GG. Antibiotic treatment of Pseudomonas aeruginosa biofilms stimulates expression of the magnesium transporter gene mgtE. MICROBIOLOGY-SGM 2013; 160:165-178. [PMID: 24162608 DOI: 10.1099/mic.0.070144-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen with the capacity to cause serious disease, including chronic biofilm infections in the lungs of cystic fibrosis (CF) patients. These infections are treated with high concentrations of antibiotics. Virulence modulation is an important tool utilized by P. aeruginosa to propagate infection and biofilm formation in the CF airway. Many different virulence modulatory pathways and proteins have been identified, including the magnesium transporter protein MgtE. We have recently found that isogenic deletion of mgtE leads to increased cytotoxicity through effects on the type III secretion system. To explore the role of the CF lung environment in MgtE activity, we investigated mgtE transcriptional regulation following antibiotic treatment. Utilizing quantitative real-time-PCR, we have demonstrated an increase in mgtE transcript levels following antibiotic treatment with most of the 12 antibiotics tested. To begin to determine the regulatory network governing mgtE expression, we screened a transposon-mutant library of P. aeruginosa to look for mutants with potentially altered mgtE activity, using cytotoxicity as a readout. In this screen, we observed that AlgR, which regulates production of the biofilm polysaccharide alginate, alters MgtE-mediated cytotoxicity. This cross-talk between MgtE and AlgR suggests that AlgR is involved in linking external inducing signals (e.g. antibiotics) to mgtE transcription and downstream virulence and biofilm activities. Analysing such interactions may lead to a better understanding of how the CF lung environment shapes P. aeruginosa biofilm infections.
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Affiliation(s)
- Carly V Redelman
- Department of Biology, Butler University, Indianapolis, IN 46208, USA.,Department of Biology, IUPUI, Indianapolis, IN 46202, USA
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14
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Development of a population pharmacokinetic model to describe azithromycin whole-blood and plasma concentrations over time in healthy subjects. Antimicrob Agents Chemother 2013; 57:3194-201. [PMID: 23629714 DOI: 10.1128/aac.02430-12] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Azithromycin (AZI), a broad-spectrum antibiotic, accumulates in polymorphonuclear cells and peripheral blood mononuclear cells. The distribution of AZI in proinflammatory cells may be important to the anti-inflammatory properties. Previous studies have described plasma AZI pharmacokinetics. The objective of this study was to describe the pharmacokinetics of AZI in whole blood (concentration in whole blood [Cb]) and plasma (concentration in plasma [Cp]) of healthy subjects. In this study, 12 subjects received AZI (500 mg once a day for 3 days). AZI Cb and Cp were quantified in serial samples collected up to 3 weeks after the last dose and analyzed using noncompartmental and compartmental methods. After the last dose, Cb was greater than Cp. Importantly, Cb, but not Cp, was quantifiable in all but one subject at 3 weeks. The blood area under the curve during a 24-h dosing interval (AUC24) was ∼2-fold greater than the plasma AUC24, but simulations suggested that Cb was not at steady state by day 3. Upon exploration of numerous models, an empirical 3-compartment model adequately described Cp and Cb, but Cp was somewhat underestimated. Intercompartmental clearance (CL; likely representing cells) was lower than apparent oral CL (18 versus 118 liters/h). Plasma, peripheral, and cell compartmental volumes were 439 liters, 2,980 liters, and 3,084 liters, respectively. Interindividual variability in CL was low (26.2%), while the volume of distribution variability was high (107%). This is the first report to describe AZI Cb in healthy subjects, the distribution parameters between Cp and Cb, and AZI retention in blood for up to 3 weeks following 3 daily doses. The model can be used to predict Cb from Cp for AZI under various dosing regimens. (This study has been registered at ClinicalTrials.gov under registration no. NCT01026064.).
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15
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Blood, tissue, and intracellular concentrations of azithromycin during and after end of therapy. Antimicrob Agents Chemother 2013; 57:1736-42. [PMID: 23357769 DOI: 10.1128/aac.02011-12] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although azithromycin is extensively used in the treatment of respiratory tract infections as well as skin and skin-related infections, pharmacokinetics of azithromycin in extracellular space fluid of soft tissues, i.e., one of its therapeutic target sites, are not yet fully elucidated. In this study, azithromycin concentration-time profiles in extracellular space of muscle and subcutaneous adipose tissue, but also in plasma and white blood cells, were determined at days 1 and 3 of treatment as well as 2 and 7 days after the end of treatment. Of all compartments, azithromycin concentrations were highest in white blood cells, attesting for intracellular accumulation. However, azithromycin concentrations in both soft tissues were markedly lower than in plasma both during and after treatment. Calculation of the area under the concentration-time curve from 0 to 24 h (AUC(0-24))/MIC(90) ratios for selected pathogens suggests that azithromycin concentrations measured in the present study are subinhibitory at all time points in both soft tissues and at the large majority of observed time points in plasma. Hence, it might be speculated that azithromycin's clinical efficacy relies not only on elevated intracellular concentrations but possibly also on its known pleotropic effects, including immunomodulation and influence on bacterial virulence factors. However, prolonged subinhibitory azithromycin concentrations at the target site, as observed in the present study, might favor the emergence of bacterial resistance and should therefore be considered with concern. In conclusion, this study has added important information to the pharmacokinetic profile of the widely used antibiotic drug azithromycin and evidentiates the need for further research on its potential for induction of bacterial resistance.
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16
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Effets immunomodulateurs des macrolides au cours des pathologies respiratoires chroniques. MEDECINE INTENSIVE REANIMATION 2013. [DOI: 10.1007/s13546-012-0639-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Wilms EB, Touw DJ, Heijerman HGM, van der Ent CK. Azithromycin maintenance therapy in patients with cystic fibrosis: a dose advice based on a review of pharmacokinetics, efficacy, and side effects. Pediatr Pulmonol 2012; 47:658-65. [PMID: 22684985 DOI: 10.1002/ppul.21620] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 10/27/2011] [Indexed: 01/31/2023]
Abstract
Azithromycin maintenance therapy results in improvement of respiratory function in patients with cystic fibrosis (CF). In azithromycin maintenance therapy, several dosing schemes are applied. In this review, we combine current knowledge about azithromycin pharmacokinetics with the dosing schedules used in clinical trials in order to come to a dosing advise which could be generally applicable. We used data from a recently updated Cochrane meta analysis (2011), the reports of clinical trials and pharmacokinetic studies. Based on these data, it was concluded that a dose level of 22-30 mg/kg/week is the lowest dose level with proven efficacy. Due to the extended half-life in patients with CF, the weekly dose of azithromycin can be divided in one to seven dosing moments, depending on patient preference and gastro-intestinal tolerance. No important side effects or interactions with other CF-related drugs have been documented so far.
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Affiliation(s)
- Erik B Wilms
- Central Hospital Pharmacy, The Hague, The Netherlands.
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18
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Bosnar M, Kragol G, Koštrun S, Vujasinović I, Bošnjak B, Bencetić Mihaljević V, Marušić Ištuk Z, Kapić S, Hrvačić B, Brajša K, Tavčar B, Jelić D, Glojnarić I, Verbanac D, Čulić O, Padovan J, Alihodžić S, Eraković Haber V, Spaventi R. N′-Substituted-2′-O,3′-N-carbonimidoyl Bridged Macrolides: Novel Anti-inflammatory Macrolides without Antimicrobial Activity. J Med Chem 2012; 55:6111-23. [DOI: 10.1021/jm300356u] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martina Bosnar
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Goran Kragol
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Sanja Koštrun
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Ines Vujasinović
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Berislav Bošnjak
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | | | - Zorica Marušić Ištuk
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Samra Kapić
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Boška Hrvačić
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Karmen Brajša
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Branka Tavčar
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Dubravko Jelić
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Ines Glojnarić
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Donatella Verbanac
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Ognjen Čulić
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Jasna Padovan
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Sulejman Alihodžić
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Vesna Eraković Haber
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
| | - Radan Spaventi
- GlaxoSmithKline Research Centre
Zagreb, Prilaz baruna Filipovića 29, Zagreb, Croatia
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Mutations in 23S rRNA confer resistance against azithromycin in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2012; 56:4519-21. [PMID: 22644032 DOI: 10.1128/aac.00630-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The emergence of antibiotic-resistant Pseudomonas aeruginosa is an important concern in the treatment of long-term airway infections in cystic fibrosis patients. In this study, we report the occurrence of azithromycin resistance among clinical P. aeruginosa DK2 isolates. We demonstrate that resistance is associated with specific mutations (A2058G, A2059G, and C2611T in Escherichia coli numbering) in domain V of 23S rRNA and that introduction of A2058G and C2611T into strain PAO1 results in azithromycin resistance.
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