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Fekete-Kertész I, Berkl Z, Buda K, Fenyvesi É, Szente L, Molnár M. Quorum quenching effect of cyclodextrins on the pyocyanin and pyoverdine production of Pseudomonas aeruginosa. Appl Microbiol Biotechnol 2024; 108:271. [PMID: 38517512 PMCID: PMC10959793 DOI: 10.1007/s00253-024-13104-7] [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: 10/08/2023] [Revised: 02/27/2024] [Accepted: 03/05/2024] [Indexed: 03/24/2024]
Abstract
Various virulence determinants in Pseudomonas aeruginosa are regulated by the quorum sensing (QS) network producing and releasing signalling molecules. Two of these virulence determinants are the pyocyanin and pyoverdine, which interfere with multiple cellular functions during infection. The application of QS-inhibiting agents, such as cyclodextrins (CDs), appears to be a promising approach. Further to method development, this research tested in large-volume test systems the effect of α- and β-CD (ACD, BCD) at 1, 5, and 10 mM concentrations on the production of pyocyanin in the P. aeruginosa model system. The concentration and time-dependent quorum quenching effect of native CDs and their derivatives on pyoverdine production was tested in a small-volume high-throughput system. In the large-volume system, both ACD and BCD significantly inhibited pyocyanin production, but ACD to a greater extent. 10 mM ACD resulted in 58% inhibition, while BCD only ~40%. Similarly, ACD was more effective in the inhibition of pyoverdine production; nevertheless, the results of RMANOVA demonstrated the significant efficiency of both ACD and BCD, as well as their derivatives. Both the contact time and the cyclodextrin treatments significantly influenced pyoverdine production. In this case, the inhibitory effect of ACD after 48 h at 12.5 mM was 57%, while the inhibitory effect of BCD and its derivatives was lower than 40%. The high-level significant inhibition of both pyocyanin and pyoverdine production by ACD was detectable. Consequently, the potential value of CDs as QS inhibitors and the antivirulence strategy should be considered. KEYPOINTS: • Applicability of a simplified method for quantification of pyocyanin production was demonstrated. • The cyclodextrins significantly affected the pyocyanin and pyoverdine production. • The native ACD exhibited the highest attenuation in pyoverdine production.
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Affiliation(s)
- Ildikó Fekete-Kertész
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem rkp. 3., Budapest, H-1111, Hungary
| | - Zsófia Berkl
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem rkp. 3., Budapest, H-1111, Hungary
| | - Kata Buda
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem rkp. 3., Budapest, H-1111, Hungary
| | - Éva Fenyvesi
- CycloLab Cyclodextrin R&D Laboratory Ltd., Illatos u. 7., Budapest, H-1097, Hungary
| | - Lajos Szente
- CycloLab Cyclodextrin R&D Laboratory Ltd., Illatos u. 7., Budapest, H-1097, Hungary
| | - Mónika Molnár
- Budapest University of Technology and Economics, Faculty of Chemical Technology and Biotechnology, Department of Applied Biotechnology and Food Science, Műegyetem rkp. 3., Budapest, H-1111, Hungary.
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2
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Banat H, Ambrus R, Csóka I. Drug combinations for inhalation: Current products and future development addressing disease control and patient compliance. Int J Pharm 2023; 643:123070. [PMID: 37230369 DOI: 10.1016/j.ijpharm.2023.123070] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/07/2023] [Accepted: 05/21/2023] [Indexed: 05/27/2023]
Abstract
Pulmonary delivery is an alternative route of administration with numerous advantages over conventional routes of administration. It provides low enzymatic exposure, fewer systemic side effects, no first-pass metabolism, and concentrated drug amounts at the site of the disease, making it an ideal route for the treatment of pulmonary diseases. Owing to the thin alveolar-capillary barrier, and large surface area that facilitates rapid absorption to the bloodstream in the lung, systemic delivery can be achieved as well. Administration of multiple drugs at one time became urgent to control chronic pulmonary diseases such as asthma and COPD, thus, development of drug combinations was proposed. Administration of medications with variable dosages from different inhalers leads to overburdening the patient and may cause low therapeutic intervention. Therefore, products that contain combined drugs to be delivered via a single inhaler have been developed to improve patient compliance, reduce different dose regimens, achieve higher disease control, and boost therapeutic effectiveness in some cases. This comprehensive review aimed to highlight the growth of drug combinations by inhalation over time, obstacles and challenges, and the possible progress to broaden the current options or to cover new indications in the future. Moreover, various pharmaceutical technologies in terms of formulation and device in correlation with inhaled combinations were discussed in this review. Hence, inhaled combination therapy is driven by the need to maintain and improve the quality of life for patients with chronic respiratory diseases; promoting drug combinations by inhalation to a higher level is a necessity.
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Affiliation(s)
- Heba Banat
- Institute of Pharmaceutical Technology and Regulatory Affairs, Faculty of Pharmacy, University of Szeged, Hungary
| | - Rita Ambrus
- Institute of Pharmaceutical Technology and Regulatory Affairs, Faculty of Pharmacy, University of Szeged, Hungary
| | - Ildikó Csóka
- Institute of Pharmaceutical Technology and Regulatory Affairs, Faculty of Pharmacy, University of Szeged, Hungary.
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3
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Wang J, Zhang Y, Chen X, Tao F, Sun B, Xie J, Chen J. Targeted delivery of inhalable drug particles in the tracheobronchial tree model of a pediatric patient with bronchopneumonia: A numerical study. Respir Physiol Neurobiol 2023; 311:104024. [PMID: 36731709 DOI: 10.1016/j.resp.2023.104024] [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: 12/21/2022] [Revised: 01/19/2023] [Accepted: 01/28/2023] [Indexed: 02/01/2023]
Abstract
Pneumonia is a common cause of hospitalization and death in children worldwide. Inhalation therapy is one of the methods treating pneumonia However, there are limited studies that distinguish between the physiology of children and adults, especially with respect to targeted drug delivery. A tracheobronchial (TB) tree model of an 11-year-old child with bronchopneumonia is selected as a testbed for in silico trials of targeted drug delivery. The airflow and particle transport are solved by the computational fluid dynamics method at an airflow rate of 15 LPM. The results indicate that the distribution of deposited particles shows aggregation on the particle release map. Point-source aerosol release (PSAR) method can significantly reduce the deposition efficiency (DE) of particles in the TB tree model. Specifically, the PSAR method can reduce the DE of large particles (i.e., 7.5 µm and 10 µm) by 7.57% and 9.61%, respectively. This enables rapid design of patient-specific treatment for different population age groups and different airway diseases.
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Affiliation(s)
- Jianwei Wang
- School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210046, China
| | - Ya Zhang
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Xiaole Chen
- School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210046, China.
| | - Feng Tao
- Zhongda Hospital, Southeast University, Nanjing, Jiangsu 210009, China
| | - Baobin Sun
- Zhongda Hospital, Southeast University, Nanjing, Jiangsu 210009, China
| | - Jun Xie
- School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210046, China
| | - Jingguo Chen
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
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4
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Wang J, Zhang Y, Chen X, Feng Y, Ren X, Yang M, Ding T. Targeted delivery of inhalable drug particles in a patient-specific tracheobronchial tree with moderate COVID-19: A numerical study. POWDER TECHNOL 2022; 405:117520. [PMID: 35602760 PMCID: PMC9110329 DOI: 10.1016/j.powtec.2022.117520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/06/2022] [Accepted: 05/12/2022] [Indexed: 02/06/2023]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has led to severe social and economic disruption worldwide. Although currently no consent has been reached on a specific therapy that can treat COVID-19 effectively, several inhalation therapy strategies have been proposed to inhibit SARS-CoV-2 infection. These strategies include inhalations of antiviral drugs, anti-inflammatory drugs, and vaccines. To investigate how to enhance the therapeutic effect by increasing the delivery efficiency (DE) of the inhaled aerosolized drug particles, a patient-specific tracheobronchial (TB) tree from the trachea up to generation 6 (G6) with moderate COVID-19 symptoms was selected as a testbed for the in silico trials of targeted drug delivery to the lung regions with pneumonia alba, i.e., the severely affected lung segments (SALS). The 3D TB tree geometry was reconstructed from spiral computed tomography (CT) scanned images. The airflow field and particle trajectories were solved using a computational fluid dynamics (CFD) based Euler-Lagrange model at an inhalation flow rate of 15 L/min. Particle release maps, which record the deposition locations of the released particles, were obtained at the inlet according to the particle trajectories. Simulation results show that particles with different diameters have similar release maps for targeted delivery to SALS. Point-source aerosol release (PSAR) method can significantly enhance the DE into the SALS. A C++ program has been developed to optimize the location of the PSAR tube. The optimized simulations indicate that the PSAR approach can at least increase the DE of the SALS by a factor of 3.2× higher than conventional random-release drug-aerosol inhalation. The presence of the PSAR tube only leads to a 7.12% change in DE of the SALS. This enables the fast design of a patient-specific treatment for reginal lung diseases.
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Affiliation(s)
- Jianwei Wang
- School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210046, China
| | - Ya Zhang
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Xiaole Chen
- School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210046, China,Corresponding author
| | - Yu Feng
- School of Chemical Engineering, Oklahoma State University, Stillwater, OK 74078, USA
| | - Xiaoyong Ren
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Minjuan Yang
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Ting Ding
- School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210046, China
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Martin I, Waters V, Grasemann H. Approaches to Targeting Bacterial Biofilms in Cystic Fibrosis Airways. Int J Mol Sci 2021; 22:ijms22042155. [PMID: 33671516 PMCID: PMC7926955 DOI: 10.3390/ijms22042155] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/14/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
The treatment of lung infection in the context of cystic fibrosis (CF) is limited by a biofilm mode of growth of pathogenic organisms. When compared to planktonically grown bacteria, bacterial biofilms can survive extremely high levels of antimicrobials. Within the lung, bacterial biofilms are aggregates of microorganisms suspended in a matrix of self-secreted proteins within the sputum. These structures offer both physical protection from antibiotics as well as a heterogeneous population of metabolically and phenotypically distinct bacteria. The bacteria themselves and the components of the extracellular matrix, in addition to the signaling pathways that direct their behaviour, are all potential targets for therapeutic intervention discussed in this review. This review touches on the successes and failures of current anti-biofilm strategies, before looking at emerging therapies and the mechanisms by which it is hoped they will overcome current limitations.
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Affiliation(s)
- Isaac Martin
- Division of Respiratory Medicine, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada;
- Correspondence:
| | - Valerie Waters
- Division of Infectious Diseases, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada;
- Department of Paediatrics and Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 0A4, Canada
| | - Hartmut Grasemann
- Division of Respiratory Medicine, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 1X8, Canada;
- Department of Paediatrics and Translational Medicine, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 0A4, Canada
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6
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Pseudomonas aeruginosa Resistance to Bacteriophages and Its Prevention by Strategic Therapeutic Cocktail Formulation. Antibiotics (Basel) 2021; 10:antibiotics10020145. [PMID: 33540528 PMCID: PMC7912912 DOI: 10.3390/antibiotics10020145] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/23/2021] [Accepted: 01/27/2021] [Indexed: 12/12/2022] Open
Abstract
Antimicrobial resistance poses a significant threat to modern healthcare as it limits treatment options for bacterial infections, particularly impacting those with chronic conditions such as cystic fibrosis (CF). Viscous mucus accumulation in the lungs of individuals genetically predisposed to CF leads to recurrent bacterial infections, necessitating prolonged antimicrobial chemotherapy. Pseudomonas aeruginosa infections are the predominant driver of CF lung disease, and airway isolates are frequently resistant to multiple antimicrobials. Bacteriophages, or phages, are viruses that specifically infect bacteria and are a promising alternative to antimicrobials for CF P. aeruginosa infections. However, the narrow host range of P. aeruginosa-targeting phages and the rapid evolution of phage resistance could limit the clinical efficacy of phage therapy. A promising approach to overcome these issues is the strategic development of mixtures of phages (cocktails). The aim is to combine phages with broad host ranges and target multiple distinct bacterial receptors to prevent the evolution of phage resistance. However, further research is required to identify and characterize phage resistance mechanisms in CF-derived P. aeruginosa, which differ from their non-CF counterparts. In this review, we consider the mechanisms of P. aeruginosa phage resistance and how these could be overcome by an effective future phage therapy formulation.
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Rouillard KR, Markovetz MR, Bacudio LG, Hill DB, Schoenfisch MH. Pseudomonas aeruginosa Biofilm Eradication via Nitric Oxide-Releasing Cyclodextrins. ACS Infect Dis 2020; 6:1940-1950. [PMID: 32510928 DOI: 10.1021/acsinfecdis.0c00246] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pseudomonas aeruginosa is the main contributor to the morbidity and mortality of cystic fibrosis (CF) patients. Chronic respiratory infections are rarely eradicated due to protection from CF mucus and the biofilm matrix. The composition of the biofilm matrix determines its viscoelastic properties and affects antibiotic efficacy. Nitric oxide (NO) can both disrupt the physical structure of the biofilm and eradicate interior colonies. The effects of a CF-like growth environment on P. aeruginosa biofilm susceptibility to NO were investigated using parallel plate macrorheology and particle tracking microrheology. Biofilms grown in the presence of mucins and DNA contained greater concentrations of DNA in the matrix and exhibited concomitantly larger viscoelastic moduli compared to those grown in tryptic soy broth. Greater viscoelastic moduli correlated with increased tolerance to tobramycin and colistin. Remarkably, NO-releasing cyclodextrins eradicated all biofilms at the same concentration. The capacity of NO-releasing cyclodextrins to eradicate P. aeruginosa biofilms irrespective of matrix composition suggests that NO-based therapies may be superior antibiofilm treatments compared to conventional antibiotics.
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Affiliation(s)
- Kaitlyn R. Rouillard
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Matthew R. Markovetz
- Marsico Lung Institute/CF Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Lawrence G. Bacudio
- Marsico Lung Institute/CF Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - David B. Hill
- Marsico Lung Institute/CF Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Vast Therapeutics, Durham, North Carolina 27703, United States
- UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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8
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Price EP, Soler Arango V, Kidd TJ, Fraser TA, Nguyen TK, Bell SC, Sarovich DS. Duplex real-time PCR assay for the simultaneous detection of Achromobacter xylosoxidans and Achromobacter spp. Microb Genom 2020; 6:mgen000406. [PMID: 32667877 PMCID: PMC7478622 DOI: 10.1099/mgen.0.000406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/26/2020] [Indexed: 01/10/2023] Open
Abstract
Several members of the Gram-negative environmental bacterial genus Achromobacter are associated with serious infections, with Achromobacter xylosoxidans being the most common. Despite their pathogenic potential, little is understood about these intrinsically drug-resistant bacteria and their role in disease, leading to suboptimal diagnosis and management. Here, we performed comparative genomics for 158 Achromobacter spp. genomes to robustly identify species boundaries, reassign several incorrectly speciated taxa and identify genetic sequences specific for the genus Achromobacter and for A. xylosoxidans. Next, we developed a Black Hole Quencher probe-based duplex real-time PCR assay, Ac-Ax, for the rapid and simultaneous detection of Achromobacter spp. and A. xylosoxidans from both purified colonies and polymicrobial clinical specimens. Ac-Ax was tested on 119 isolates identified as Achromobacter spp. using phenotypic or genotypic methods. In comparison to these routine diagnostic methods, the duplex assay showed superior identification of Achromobacter spp. and A. xylosoxidans, with five Achromobacter isolates failing to amplify with Ac-Ax confirmed to be different genera according to 16S rRNA gene sequencing. Ac-Ax quantified both Achromobacter spp. and A. xylosoxidans down to ~110 genome equivalents and detected down to ~12 and ~1 genome equivalent(s), respectively. Extensive in silico analysis, and laboratory testing of 34 non-Achromobacter isolates and 38 adult cystic fibrosis sputa, confirmed duplex assay specificity and sensitivity. We demonstrate that the Ac-Ax duplex assay provides a robust, sensitive and cost-effective method for the simultaneous detection of all Achromobacter spp. and A. xylosoxidans and will facilitate the rapid and accurate diagnosis of this important group of pathogens.
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Affiliation(s)
- Erin P. Price
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
- Sunshine Coast Health Institute, Birtinya, Queensland, Australia
| | - Valentina Soler Arango
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
- Sunshine Coast Health Institute, Birtinya, Queensland, Australia
| | - Timothy J. Kidd
- School of Chemistry and Molecular Biosciences, Faculty of Science, The University of Queensland, St Lucia, Queensland, Australia
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Tamieka A. Fraser
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
- Sunshine Coast Health Institute, Birtinya, Queensland, Australia
| | - Thuy-Khanh Nguyen
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Scott C. Bell
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
- Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Derek S. Sarovich
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
- Sunshine Coast Health Institute, Birtinya, Queensland, Australia
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Armijo LM, Wawrzyniec SJ, Kopciuch M, Brandt YI, Rivera AC, Withers NJ, Cook NC, Huber DL, Monson TC, Smyth HDC, Osiński M. Antibacterial activity of iron oxide, iron nitride, and tobramycin conjugated nanoparticles against Pseudomonas aeruginosa biofilms. J Nanobiotechnology 2020; 18:35. [PMID: 32070354 PMCID: PMC7029462 DOI: 10.1186/s12951-020-0588-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 01/29/2020] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Novel methods are necessary to reduce morbidity and mortality of patients suffering from infections with Pseudomonas aeruginosa. Being the most common infectious species of the Pseudomonas genus, P. aeruginosa is the primary Gram-negative etiology responsible for nosocomial infections. Due to the ubiquity and high adaptability of this species, an effective universal treatment method for P. aeruginosa infection still eludes investigators, despite the extensive research in this area. RESULTS We report bacterial inhibition by iron-oxide (nominally magnetite) nanoparticles (NPs) alone, having a mean hydrodynamic diameter of ~ 16 nm, as well as alginate-capped iron-oxide NPs. Alginate capping increased the average hydrodynamic diameter to ~ 230 nm. We also investigated alginate-capped iron-oxide NP-drug conjugates, with a practically unchanged hydrodynamic diameter of ~ 232 nm. Susceptibility and minimum inhibitory concentration (MIC) of the NPs, NP-tobramycin conjugates, and tobramycin alone were determined in the PAO1 bacterial colonies. Investigations into susceptibility using the disk diffusion method were done after 3 days of biofilm growth and after 60 days of growth. MIC of all compounds of interest was determined after 60-days of growth, to ensure thorough establishment of biofilm colonies. CONCLUSIONS Positive inhibition is reported for uncapped and alginate-capped iron-oxide NPs, and the corresponding MICs are presented. We report zero susceptibility to iron-oxide NPs capped with polyethylene glycol, suggesting that the capping agent plays a major role in enabling bactericidal ability in of the nanocomposite. Our findings suggest that the alginate-coated nanocomposites investigated in this study have the potential to overcome the bacterial biofilm barrier. Magnetic field application increases the action, likely via enhanced diffusion of the iron-oxide NPs and NP-drug conjugates through mucin and alginate barriers, which are characteristic of cystic-fibrosis respiratory infections. We demonstrate that iron-oxide NPs coated with alginate, as well as alginate-coated magnetite-tobramycin conjugates inhibit P. aeruginosa growth and biofilm formation in established colonies. We have also determined that susceptibility to tobramycin decreases for longer culture times. However, susceptibility to the iron-oxide NP compounds did not demonstrate any comparable decrease with increasing culture time. These findings imply that iron-oxide NPs are promising lower-cost alternatives to silver NPs in antibacterial coatings, solutions, and drugs, as well as other applications in which microbial abolition or infestation prevention is sought.
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Affiliation(s)
- Leisha M. Armijo
- Center for High Technology Materials, University of New Mexico, 1313 Goddard Street SE, Albuquerque, NM 87106-4343 USA
| | - Stephen J. Wawrzyniec
- Center for High Technology Materials, University of New Mexico, 1313 Goddard Street SE, Albuquerque, NM 87106-4343 USA
| | - Michael Kopciuch
- Center for High Technology Materials, University of New Mexico, 1313 Goddard Street SE, Albuquerque, NM 87106-4343 USA
| | - Yekaterina I. Brandt
- Center for High Technology Materials, University of New Mexico, 1313 Goddard Street SE, Albuquerque, NM 87106-4343 USA
| | - Antonio C. Rivera
- Center for High Technology Materials, University of New Mexico, 1313 Goddard Street SE, Albuquerque, NM 87106-4343 USA
| | - Nathan J. Withers
- Center for High Technology Materials, University of New Mexico, 1313 Goddard Street SE, Albuquerque, NM 87106-4343 USA
| | - Nathaniel C. Cook
- Center for High Technology Materials, University of New Mexico, 1313 Goddard Street SE, Albuquerque, NM 87106-4343 USA
| | - Dale L. Huber
- Center for Integrated Nanotechnologies, Sandia National Laboratories, 1000 Eubank SE, Albuquerque, NM 87123 USA
| | - Todd C. Monson
- Sandia National Laboratories, Nanomaterials Sciences, P.O. Box 5800, MS 1415, Albuquerque, NM 87185 USA
| | - Hugh D. C. Smyth
- College of Pharmacy, The University of Texas at Austin, 2409 University Avenue, Stop A1900, Austin, TX 78712 USA
| | - Marek Osiński
- Center for High Technology Materials, University of New Mexico, 1313 Goddard Street SE, Albuquerque, NM 87106-4343 USA
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10
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Ganesh PS, Vishnupriya S, Vadivelu J, Mariappan V, Vellasamy KM, Shankar EM. Intracellular survival and innate immune evasion of Burkholderia cepacia: Improved understanding of quorum sensing-controlled virulence factors, biofilm, and inhibitors. Microbiol Immunol 2020; 64:87-98. [PMID: 31769530 DOI: 10.1111/1348-0421.12762] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/18/2019] [Accepted: 11/21/2019] [Indexed: 12/25/2022]
Abstract
Burkholderia cepacia complex (Bcc) are opportunistic pathogens implicated with nosocomial infections, and high rates of morbidity and mortality, especially in individuals with cystic fibrosis (CF). B. cepacia are naturally resistant to different classes of antibiotics, and can subvert the host innate immune responses by producing quorum sensing (QS) controlled virulence factors and biofilms. It still remains a conundrum as to how exactly the bacterium survives the intracellular environment within the host cells of CF patients and immunocompromised individuals although the bacterium can invade human lung epithelial cells, neutrophils, and murine macrophages. The mechanisms associated with intracellular survival in the airway epithelial cells and the role of QS and virulence factors in B. cepacia infections in cystic fibrosis remain largely unclear. The current review focuses on understanding the role of QS-controlled virulence factors and biofilms, and provides additional impetus to understanding the potentials of QS-inhibitory strategies against B. cepacia.
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Affiliation(s)
- Pitchaipillai Sankar Ganesh
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - Sivakumar Vishnupriya
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Vanitha Mariappan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kumutha M Vellasamy
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Esaki M Shankar
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
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11
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Scott A, Pottenger S, Timofte D, Moore M, Wright L, Kukavica-Ibrulj I, Jeukens J, Levesque RC, Freschi L, Pinchbeck GL, Schmidt VM, McEwan N, Radford AD, Fothergill JL. Reservoirs of resistance: polymyxin resistance in veterinary-associated companion animal isolates of Pseudomonas aeruginosa. Vet Rec 2019; 185:206. [PMID: 31239295 DOI: 10.1136/vr.105075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 05/16/2019] [Accepted: 05/27/2019] [Indexed: 11/03/2022]
Abstract
BACKGROUND Pseudomonas aeruginosa is an opportunistic pathogen and a major cause of infections. Widespread resistance in human infections are increasing the use of last resort antimicrobials such as polymyxins. However, these have been used for decades in veterinary medicine. Companion animals are an understudied source of antimicrobial resistant P. aeruginosa isolates. This study evaluated the susceptibility of P. aeruginosa veterinary isolates to polymyxins to determine whether the veterinary niche represents a potential reservoir of resistance genes for pathogenic bacteria in both animals and humans. METHODS AND RESULTS Clinical P. aeruginosa isolates (n=24) from UK companion animals were compared for antimicrobial susceptibility to a panel of human-associated isolates (n=37). Minimum inhibitory concentration (MIC) values for polymyxin B and colistin in the companion animals was significantly higher than in human isolates (P=0.033 and P=0.013, respectively). Genotyping revealed that the veterinary isolates were spread throughout the P. aeruginosa population, with shared array types from human infections such as keratitis and respiratory infections, suggesting the potential for zoonotic transmission. Whole genome sequencing revealed mutations in genes associated with polymyxin resistance and other antimicrobial resistance-related genes. CONCLUSION The high levels of resistance to polymyxin shown here, along with genetic similarities between some human and animal isolates, together suggest a need for sustained surveillance of this veterinary niche as a potential reservoir for resistant, clinically relevant bacteria in both animals and humans.
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Affiliation(s)
- Andrea Scott
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Sian Pottenger
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Dorina Timofte
- Institute of Veterinary Science, University of Liverpool, Neston, Wirral, UK
| | - Matthew Moore
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Laura Wright
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | | | | | | | | | - Gina L Pinchbeck
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Vanessa M Schmidt
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.,Institute of Veterinary Science, University of Liverpool, Neston, Wirral, UK
| | - Neil McEwan
- Institute of Veterinary Science, University of Liverpool, Neston, Wirral, UK
| | - Alan D Radford
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Joanne L Fothergill
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
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12
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Debbabi S, Groleau MC, Létourneau M, Narayanan C, Gosselin LL, Iddir M, Gagnon J, Doucet N, Déziel E, Chatenet D. Antibacterial properties of the pituitary adenylate cyclase-activating polypeptide: A new human antimicrobial peptide. PLoS One 2018; 13:e0207366. [PMID: 30462698 PMCID: PMC6248945 DOI: 10.1371/journal.pone.0207366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 10/30/2018] [Indexed: 02/04/2023] Open
Abstract
The Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP), a polycationic, amphiphilic and helical neuropeptide, is well known for its neuroprotective actions and cell penetrating properties. In the present study, we evaluated the potent antibacterial property of PACAP38 and related analogs against various bacterial strains. Interestingly, PACAP38 and related analogs can inhibit the growth of various bacteria including Escherichia coli (JM109), Bacillus subtilis (PY79), and the pathogenic Burkholderia cenocepacia (J2315). Investigation of the mechanism of action suggested that a PACAP metabolite, identified as PACAP(9–38), might indeed be responsible for the observed PACAP38 antibacterial action. Surprisingly, PACAP(9–38), which does not induce haemolysis, exhibits an increased specificity toward Burkholderia cenocepacia J2315 compared to other tested bacteria. Finally, the predisposition of PACAP(9–38) to adopt a π-helix conformation rather than an α-helical conformation like PACAP38 could explain this gain in specificity. Overall, this study has revealed a new function for PACAP38 and related derivatives that can be added to its pleiotropic biological activities. This innovative study could therefore pave the way toward the development of new therapeutic agents against multiresistant bacteria, and more specifically the Burkholderia cenocepacia complex.
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Affiliation(s)
- Somia Debbabi
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
| | | | - Myriam Létourneau
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
| | - Chitra Narayanan
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
| | - Laura-Lee Gosselin
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
| | - Mustapha Iddir
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
| | - Jacinthe Gagnon
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
| | - Nicolas Doucet
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
| | - Eric Déziel
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
- * E-mail: (DC); (ED)
| | - David Chatenet
- INRS–Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada
- * E-mail: (DC); (ED)
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13
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Avedissian SN, Miglis C, Kubin CJ, Rhodes NJ, Yin MT, Cremers S, Prickett M, Scheetz MH. Polymyxin B Pharmacokinetics in Adult Cystic Fibrosis Patients. Pharmacotherapy 2018; 38:730-738. [PMID: 29800496 DOI: 10.1002/phar.2129] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVES Polymyxin B pharmacokinetics (PK) in adults with cystic fibrosis (CF) are not well described. The goals of this pilot study were to identify a PK model for patients with CF receiving polymyxin B with exploration of covariate relationships of the PK parameters, to compare polymyxin B PK parameters in adults without CF, and to probe exposures associated with different dosing schemes through simulation. METHODS Adult patients with CF treated with polymyxin B at New York-Presbyterian Hospital had PK samples measured by liquid chromatography-mass spectrometry (MS)/MS. Multiple PK models were fit utilizing Pmetrics for R. Model covariates considered included: age, total body weight, creatinine clearance, albumin, and body mass index. PK parameters in CF patients were compared with PK parameters for 53 adults without CF who were receiving polymyxin B from the same institution. Simulations with target exposure (area under the curve)/minimum inhibitory concentration (MIC) of 20 mg*L/h were conducted for different dosing schemes and MIC ranges. MAIN RESULTS Nine patients with CF received between 58 and 240 mg of polymyxin B (median 1.47 mg/kg/dose [IQR (1.43-1.65)]). A two-compartment model adjusting polymyxin B clearance for patient CrCl was better than a standard two-compartment model (p=0.004) in CF patients. When compared to PK parameters for patients without CF, PK parameters of polymyxin B in CF were similar (p>0.05). Simulations for plasma concentrations showed all regimens performed adequately at MICs between 0.03125 and 0.125 mg/L but not at increasing MICs of 1 and 2 mg/L. CONCLUSIONS In this pilot study of polymyxin B PK in adults with CF, the PK parameters of polymyxin B were mostly similar to adults without CF. We observed a potential association between CrCl and polymyxin B clearance, which stands in contrast to the general adult population. However, this observation requires further study. Additional studies focusing on optimal and safe polymyxin B dosing in CF are needed.
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Affiliation(s)
- Sean N Avedissian
- Department of Pharmacy Practice, Midwestern University Chicago College of Pharmacy, Downers Grove, Illinois
| | - Cristina Miglis
- Department of Pharmacy Practice, Midwestern University Chicago College of Pharmacy, Downers Grove, Illinois
| | - Christine J Kubin
- Department of Pharmacy, NewYork-Presbyterian Hospital, New York City, New York.,Division of Infectious Diseases, Columbia University Irving Medical Center, New York City, New York
| | - Nathaniel J Rhodes
- Department of Pharmacy Practice, Midwestern University Chicago College of Pharmacy, Downers Grove, Illinois
| | - Michael T Yin
- Division of Infectious Diseases, Columbia University Irving Medical Center, New York City, New York
| | - Serge Cremers
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York City, New York
| | - Michelle Prickett
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Marc H Scheetz
- Department of Pharmacy Practice, Midwestern University Chicago College of Pharmacy, Downers Grove, Illinois
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14
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Lim SZP, Fitzgerald DA. Treating resistant Pseudomonas aeruginosa lung disease in young children with cystic fibrosis. Paediatr Respir Rev 2018; 27:33-36. [PMID: 29033215 DOI: 10.1016/j.prrv.2017.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 08/25/2017] [Indexed: 12/28/2022]
Abstract
Pseudomonas aeruginosa is a common bacterial pathogen in the evolution of bronchiectasis in cystic fibrosis. The appearance of resistant strains of pseudomonas is increasing with the earlier and more liberal use of a range of anti-pseudomonal antibiotics for the treatment of bacterial chest infections. The rationale for treatment and potential benefits of aggressive treatment of resistant strains of Pseudomonas aeruginosa from early in life are discussed.
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Affiliation(s)
- Sandy Z P Lim
- Sydney Medical School, University of Sydney, Australia
| | - Dominic A Fitzgerald
- The Children's Hospital at Westmead, Sydney, Australia; Sydney Medical School, Discipline Paediatrics & Child Health, University of Sydney, Australia.
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15
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Garg N, Wang M, Hyde E, da Silva RR, Melnik AV, Protsyuk I, Bouslimani A, Lim YW, Wong R, Humphrey G, Ackermann G, Spivey T, Brouha SS, Bandeira N, Lin GY, Rohwer F, Conrad DJ, Alexandrov T, Knight R, Dorrestein PC. Three-Dimensional Microbiome and Metabolome Cartography of a Diseased Human Lung. Cell Host Microbe 2017; 22:705-716.e4. [PMID: 29056429 DOI: 10.1016/j.chom.2017.10.001] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/12/2017] [Accepted: 09/14/2017] [Indexed: 12/12/2022]
Abstract
Our understanding of the spatial variation in the chemical and microbial makeup of an entire human organ remains limited, in part due to the size and heterogeneity of human organs and the complexity of the associated metabolome and microbiome. To address this challenge, we developed a workflow to enable the cartography of metabolomic and microbiome data onto a three-dimensional (3D) organ reconstruction built off radiological images. This enabled the direct visualization of the microbial and chemical makeup of a human lung from a cystic fibrosis patient. We detected host-derived molecules, microbial metabolites, medications, and region-specific metabolism of medications and placed it in the context of microbial distributions in the lung. Our tool further created browsable maps of a 3D microbiome/metabolome reconstruction map on a radiological image of a human lung and forms an interactive resource for the scientific community.
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Affiliation(s)
- Neha Garg
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mingxun Wang
- Department of Computer Science & Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Embriette Hyde
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ricardo R da Silva
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Alexey V Melnik
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ivan Protsyuk
- Structural and Computational Biology, European Molecular Biology Laboratory, Heidelberg 69117, Germany
| | - Amina Bouslimani
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yan Wei Lim
- Biology Department, San Diego State University, San Diego, CA, USA
| | - Richard Wong
- Department of Pathology, University of California, San Diego Health, San Diego, CA 92103, USA
| | - Greg Humphrey
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gail Ackermann
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Timothy Spivey
- Department of Radiology, University of California, San Diego Health, San Diego, CA 92103, USA
| | - Sharon S Brouha
- Department of Radiology, University of California, San Diego Health, San Diego, CA 92103, USA
| | - Nuno Bandeira
- Department of Computer Science & Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Grace Y Lin
- Department of Pathology, University of California, San Diego Health, San Diego, CA 92103, USA
| | - Forest Rohwer
- Biology Department, San Diego State University, San Diego, CA, USA
| | - Douglas J Conrad
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Theodore Alexandrov
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Structural and Computational Biology, European Molecular Biology Laboratory, Heidelberg 69117, Germany.
| | - Rob Knight
- Department of Computer Science & Engineering, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Center for Microbiome Innovation, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Pieter C Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Department of Computer Science & Engineering, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Center for Microbiome Innovation, University of California, San Diego, La Jolla, CA 92093, USA.
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16
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Ideozu JE, Zhang X, Pan A, Ashrafi Z, Woods KJ, Hessner MJ, Simpson P, Levy H. Increased Expression of Plasma-Induced ABCC1 mRNA in Cystic Fibrosis. Int J Mol Sci 2017; 18:E1752. [PMID: 28800122 PMCID: PMC5578142 DOI: 10.3390/ijms18081752] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/01/2017] [Accepted: 08/08/2017] [Indexed: 01/24/2023] Open
Abstract
The ABCC1 gene is structurally and functionally related to the cystic fibrosis transmembrane conductance regulator gene (CFTR). Upregulation of ABCC1 is thought to improve lung function in patients with cystic fibrosis (CF); the mechanism underlying this effect is unknown. We analyzed the ABCC1 promoter single nucleotide polymorphism (SNP rs504348), plasma-induced ABCC1 mRNA expression levels, and ABCC1 methylation status and their correlation with clinical variables among CF subjects with differing CFTR mutations. We assigned 93 CF subjects into disease severity groups and genotyped SNP rs504348. For 23 CF subjects and 7 healthy controls, donor peripheral blood mononuclear cells (PBMCs) stimulated with plasma underwent gene expression analysis via qRT-PCR. ABCC1 promoter methylation was analyzed in the same 23 CF subjects. No significant correlation was observed between rs504348 genotypes and CF disease severity, but pancreatic insufficient CF subjects showed increased colonization with any form of Pseudomonas aeruginosa (OR = 3.125, 95% CI: 1.192-8.190) and mucoid P. aeruginosa (OR = 5.075, 95% CI: 1.307-28.620) compared to the pancreatic sufficient group. A significantly higher expression of ABCC1 mRNA was induced by CF plasma compared to healthy control plasma (p < 0.001). CF subjects with rs504348 (CC/CG) also had higher mRNA expression compared to those with the ancestral GG genotype (p < 0.005). ABCC1 promoter was completely unmethylated; therefore, we did not detect any association between methylation and CF disease severity. In silico predictions suggested that histone modifications are crucial for regulating ABCC1 expression in PBMCs. Our results suggest that ABCC1 expression has a role in CFTR activity thereby increasing our understanding of the molecular underpinnings of the clinical heterogeneity in CF.
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Affiliation(s)
- Justin E Ideozu
- Division of Pulmonary Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave., Chicago, IL 60611, USA.
- Human Molecular Genetics Program, Stanley Manne Children's Research Institute, Chicago, IL 60614, USA.
| | - Xi Zhang
- Division of Pulmonary Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave., Chicago, IL 60611, USA.
- Human Molecular Genetics Program, Stanley Manne Children's Research Institute, Chicago, IL 60614, USA.
| | - Amy Pan
- Department of Pediatrics, Division of Quantitative Health Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Zainub Ashrafi
- Division of Pulmonary Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave., Chicago, IL 60611, USA.
| | - Katherine J Woods
- Department of Pediatrics, Division of Critical Care, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Martin J Hessner
- Department of Pediatrics, Max McGee National Research Center for Juvenile Diabetes, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Pippa Simpson
- Department of Pediatrics, Division of Quantitative Health Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Hara Levy
- Division of Pulmonary Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave., Chicago, IL 60611, USA.
- Human Molecular Genetics Program, Stanley Manne Children's Research Institute, Chicago, IL 60614, USA.
- Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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17
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Stefani S, Campana S, Cariani L, Carnovale V, Colombo C, Lleo MM, Iula VD, Minicucci L, Morelli P, Pizzamiglio G, Taccetti G. Relevance of multidrug-resistant Pseudomonas aeruginosa infections in cystic fibrosis. Int J Med Microbiol 2017; 307:353-362. [PMID: 28754426 DOI: 10.1016/j.ijmm.2017.07.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 01/15/2023] Open
Abstract
Multidrug-resistant (MDR) Pseudomonas aeruginosa is an important issue for physicians who take care of patients with cystic fibrosis (CF). Here, we review the latest research on how P. aeruginosa infection causes lung function to decline and how several factors contribute to the emergence of antibiotic resistance in P. aeruginosa strains and influence the course of the infection course. However, many aspects of the practical management of patients with CF infected with MDR P. aeruginosa are still to be established. Less is known about the exact role of susceptibility testing in clinical strategies for dealing with resistant infections, and there is an urgent need to find a tool to assist in choosing the best therapeutic strategy for MDR P. aeruginosa infection. One current perception is that the selection of antibiotic therapy according to antibiogram results is an important component of the decision-making process, but other patient factors, such as previous infection history and antibiotic courses, also need to be evaluated. On the basis of the known issues and the best current data on respiratory infections caused by MDR P. aeruginosa, this review provides practical suggestions to optimize the diagnostic and therapeutic management of patients with CF who are infected with these pathogens.
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Affiliation(s)
- S Stefani
- Department of Biomedical and Biotechnological Sciences, Division of Microbiology, University of Catania, Catania, Italy.
| | - S Campana
- Department of Paediatric Medicine, Cystic Fibrosis Centre, Anna Meyer Children's University Hospital, Florence, Italy
| | - L Cariani
- Cystic Fibrosis Microbiology Laboratory, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - V Carnovale
- Department of Translational Medical Sciences, Cystic Fibrosis Center, University "Federico II", Naples, Italy
| | - C Colombo
- Cystic Fibrosis Center, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - M M Lleo
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - V D Iula
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, Naples, Italy
| | - L Minicucci
- Microbiology Laboratory, Cystic Fibrosis Center, G. Gaslini Institute, Genoa, Italy
| | - P Morelli
- Department of Paediatric, Cystic Fibrosis Center, G. Gaslini Institute, Genoa, Italy
| | - G Pizzamiglio
- Respiratory Disease Department, Cystic Fibrosis Center Adult Section, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico Milano, Milan, Italy
| | - G Taccetti
- Department of Paediatric Medicine, Cystic Fibrosis Centre, Anna Meyer Children's University Hospital, Florence, Italy
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18
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Rath SN, Ray M, Pattnaik A, Pradhan SK. Drug Target Identification and Elucidation of Natural Inhibitors for Bordetella petrii: An In Silico Study. Genomics Inform 2016; 14:241-254. [PMID: 28154518 PMCID: PMC5287131 DOI: 10.5808/gi.2016.14.4.241] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 11/24/2016] [Accepted: 11/24/2016] [Indexed: 11/20/2022] Open
Abstract
Environmental microbes like Bordetella petrii has been established as a causative agent for various infectious diseases in human. Again, development of drug resistance in B. petrii challenged to combat against the infection. Identification of potential drug target and proposing a novel lead compound against the pathogen has a great aid and value. In this study, bioinformatics tools and technology have been applied to suggest a potential drug target by screening the proteome information of B. petrii DSM 12804 (accession No. PRJNA28135) from genome database of National Centre for Biotechnology information. In this regards, the inhibitory effect of nine natural compounds like ajoene (Allium sativum), allicin (A. sativum), cinnamaldehyde (Cinnamomum cassia), curcumin (Curcuma longa), gallotannin (active component of green tea and red wine), isoorientin (Anthopterus wardii), isovitexin (A. wardii), neral (Melissa officinalis), and vitexin (A. wardii) have been acknowledged with anti-bacterial properties and hence tested against identified drug target of B. petrii by implicating computational approach. The in silico studies revealed the hypothesis that lpxD could be a potential drug target and with recommendation of a strong inhibitory effect of selected natural compounds against infection caused due to B. petrii, would be further validated through in vitro experiments.
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Affiliation(s)
- Surya Narayan Rath
- BIF Centre, Department of Bioinformatics, Orissa University of Agriculture and Technology, Bhubaneswar 751003, India
| | - Manisha Ray
- BIF Centre, Department of Bioinformatics, Orissa University of Agriculture and Technology, Bhubaneswar 751003, India
| | - Animesh Pattnaik
- BIF Centre, Department of Bioinformatics, Orissa University of Agriculture and Technology, Bhubaneswar 751003, India
| | - Sukanta Kumar Pradhan
- BIF Centre, Department of Bioinformatics, Orissa University of Agriculture and Technology, Bhubaneswar 751003, India
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19
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Wang A, Wang Q, Kudinha T, Xiao S, Zhuo C. Effects of Fluoroquinolones and Azithromycin on Biofilm Formation of Stenotrophomonas maltophilia. Sci Rep 2016; 6:29701. [PMID: 27405358 PMCID: PMC4942784 DOI: 10.1038/srep29701] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 06/23/2016] [Indexed: 12/16/2022] Open
Abstract
Stenotrophomonas maltophilia is an opportunistic pathogen that causes respiratory and urinary tract infections, as well as wound infections in immunocompromised patients. This pathogen is difficult to treat due to increased resistance to many antimicrobial agents. We investigated the in vitro biofilm formation of S. maltophilia, including effects of fluoroquinolones (FQs) and azithromycin on biofilm formation. The organism initiated attachment to polystyrene surfaces after a 4 h incubation period, and reached maximal growth at 18–24 h. In the presence of FQs (moxifloxacin, levofloxacin or ciprofloxacin), the biofilm biomass was significantly reduced (P < 0.05). A lower concentration of moxifloxacin (10 μg/mL) exhibited a better inhibiting effect on biofilm formation than 100 μg/mL (P < 0.01), but with no difference in effect compared to the 50 μg/mL concentration (P > 0.05). However, the inhibitory effects of 10 μg/mL of levofloxacin or ciprofloxacin were slightly less pronounced than those of the higher concentrations. A combination of azithromycin and FQs significantly reduced the biofilm inhibiting effect on S. maltophilia preformed biofilms compared to azithromycin or FQs alone. We conclude that early use of clinically acceptable concentrations of FQs, especially moxifloxacin (10 μg/mL), may possibly inhibit biofilm formation by S. maltophilia. Our study provides an experimental basis for a possible optimal treatment strategy for S. maltophilia biofilm-related infections.
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Affiliation(s)
- Aihua Wang
- State Key Laboratory of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qinqin Wang
- Department of Respiratory Medicine, the First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Timothy Kudinha
- Centre for Infectious Diseases and Microbiology Services, ICPMR-Pathology West, Westmead Hospital, University of Sydney, Darcy Road, New South Wales, Australia
| | - Shunian Xiao
- State Key Laboratory of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Chao Zhuo
- State Key Laboratory of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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20
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Kumar B, Cardona ST. Synthetic Cystic Fibrosis Sputum Medium Regulates Flagellar Biosynthesis through the flhF Gene in Burkholderia cenocepacia. Front Cell Infect Microbiol 2016; 6:65. [PMID: 27379216 PMCID: PMC4905959 DOI: 10.3389/fcimb.2016.00065] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/30/2016] [Indexed: 12/03/2022] Open
Abstract
Burkholderia cenocepacia belongs to the Burkholderia cepacia complex (Bcc), a group of at least 18 distinct species that establish chronic infections in the lung of people with the genetic disease cystic fibrosis (CF). The sputum of CF patients is rich in amino acids and was previously shown to increase flagellar gene expression in B. cenocepacia. We examined flagellin expression and flagellar morphology of B. cenocepacia grown in synthetic cystic fibrosis sputum medium (SCFM) compared to minimal medium. We found that CF nutritional conditions induce increased motility and flagellin expression. Individual amino acids added at the same concentrations as found in SCFM also increased motility but not flagellin expression, suggesting a chemotactic effect of amino acids. Electron microscopy and flagella staining demonstrated that the increase in flagellin corresponds to a change in the number of flagella per cell. In minimal medium, the ratio of multiple: single: aflagellated cells was 2:3.5:4.5; while under SCFM conditions, the ratio was 7:2:1. We created a deletion mutant, ΔflhF, to study whether this putative GTPase regulates the flagellation pattern of B. cenocepacia K56-2 during growth in CF conditions. The ΔflhF mutant exhibited 80% aflagellated, 14% single and 6% multiple flagellated bacterial subpopulations. Moreover, the ratio of multiple to single flagella in WT and ΔflhF was 3.5 and 0.43, respectively in CF conditions. The observed differences suggest that FlhF positively regulates flagellin expression and the flagellation pattern in B. cenocepacia K56-2 during CF nutritional conditions.
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Affiliation(s)
- Brijesh Kumar
- Department of Microbiology, University of Manitoba Winnipeg, MB, Canada
| | - Silvia T Cardona
- Department of Microbiology, University of ManitobaWinnipeg, MB, Canada; Department of Medical Microbiology and Infectious Diseases, University of ManitobaWinnipeg, MB, Canada
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Combination Antibiotic Therapy for the Definitive Management of Select Multidrug-Resistant Gram-Negative Rod Infections. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2015. [DOI: 10.1007/s40506-015-0066-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Ormerod KL, George NM, Fraser JA, Wainwright C, Hugenholtz P. Comparative genomics of non-pseudomonal bacterial species colonising paediatric cystic fibrosis patients. PeerJ 2015; 3:e1223. [PMID: 26401445 PMCID: PMC4579023 DOI: 10.7717/peerj.1223] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/10/2015] [Indexed: 12/16/2022] Open
Abstract
The genetic disorder cystic fibrosis is a life-limiting condition affecting ∼70,000 people worldwide. Targeted, early, treatment of the dominant infecting species, Pseudomonas aeruginosa, has improved patient outcomes; however, there is concern that other species are now stepping in to take its place. In addition, the necessarily long-term antibiotic therapy received by these patients may be providing a suitable environment for the emergence of antibiotic resistance. To investigate these issues, we employed whole-genome sequencing of 28 non-Pseudomonas bacterial strains isolated from three paediatric patients. We did not find any trend of increasing antibiotic resistance (either by mutation or lateral gene transfer) in these isolates in comparison with other examples of the same species. In addition, each isolate contained a virulence gene repertoire that was similar to other examples of the relevant species. These results support the impaired clearance of the CF lung not demanding extensive virulence for survival in this habitat. By analysing serial isolates of the same species we uncovered several examples of strain persistence. The same strain of Staphylococcus aureus persisted for nearly a year, despite administration of antibiotics to which it was shown to be sensitive. This is consistent with previous studies showing antibiotic therapy to be inadequate in cystic fibrosis patients, which may also explain the lack of increasing antibiotic resistance over time. Serial isolates of two naturally multi-drug resistant organisms, Achromobacter xylosoxidans and Stenotrophomonas maltophilia, revealed that while all S. maltophilia strains were unique, A. xylosoxidans persisted for nearly five years, making this a species of particular concern. The data generated by this study will assist in developing an understanding of the non-Pseudomonas species associated with cystic fibrosis.
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Affiliation(s)
- Kate L. Ormerod
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Narelle M. George
- Health Support Queensland, Department of Health, Queensland Government, Herston, Queensland, Australia
| | - James A. Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Claire Wainwright
- School of Medicine, University of Queensland, Brisbane, Queensland, Australia
- Department of Respiratory and Sleep Medicine, Lady Cilento Children’s Hospital, South Brisbane, Queensland, Australia
- Queensland Children’s Medical Research Insitute, Herston, Queensland, Australia
| | - Philip Hugenholtz
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
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Selective Sweeps and Parallel Pathoadaptation Drive Pseudomonas aeruginosa Evolution in the Cystic Fibrosis Lung. mBio 2015; 6:e00981-15. [PMID: 26330513 PMCID: PMC4556809 DOI: 10.1128/mbio.00981-15] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED Pulmonary infections caused by Pseudomonas aeruginosa are a recalcitrant problem in cystic fibrosis (CF) patients. While the clinical implications and long-term evolutionary patterns of these infections are well studied, we know little about the short-term population dynamics that enable this pathogen to persist despite aggressive antimicrobial therapy. Here, we describe a short-term population genomic analysis of 233 P. aeruginosa isolates collected from 12 sputum specimens obtained over a 1-year period from a single patient. Whole-genome sequencing and antimicrobial susceptibility profiling identified the expansion of two clonal lineages. The first lineage originated from the coalescence of the entire sample less than 3 years before the end of the study and gave rise to a high-diversity ancestral population. The second expansion occurred 2 years later and gave rise to a derived population with a strong signal of positive selection. These events show characteristics consistent with recurrent selective sweeps. While we cannot identify the specific mutations responsible for the origins of the clonal lineages, we find that the majority of mutations occur in loci previously associated with virulence and resistance. Additionally, approximately one-third of all mutations occur in loci that are mutated multiple times, highlighting the importance of parallel pathoadaptation. One such locus is the gene encoding penicillin-binding protein 3, which received three independent mutations. Our functional analysis of these alleles shows that they provide differential fitness benefits dependent on the antibiotic under selection. These data reveal that bacterial populations can undergo extensive and dramatic changes that are not revealed by lower-resolution analyses. IMPORTANCE Pseudomonas aeruginosa is a bacterial opportunistic pathogen responsible for significant morbidity and mortality in cystic fibrosis (CF) patients. Once it has colonized the lung in CF, it is highly resilient and rarely eradicated. This study presents a deep sampling examination of the fine-scale evolutionary dynamics of P. aeruginosa in the lungs of a chronically infected CF patient. We show that diversity of P. aeruginosa is driven by recurrent clonal emergence and expansion within this patient and identify potential adaptive variants associated with these events. This high-resolution sequencing strategy thus reveals important intraspecies dynamics that explain a clinically important phenomenon not evident at a lower-resolution analysis of community structure.
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Abstract
The ability to deliver drugs to specific sites in the lung could radically improve therapeutic outcomes of a variety of lung diseases, including cystic fibrosis, severe bronchopneumonia, chronic obstructive pulmonary disease, and lung cancer. Using conventional methods for pulmonary drug administration, precise, localized delivery of exact doses of drugs to target regions remains challenging. Here we describe a more controlled delivery of soluble reagents (e.g., drugs, enzymes, and radionuclides) in microvolume liquid plugs to targeted branches of the pulmonary airway tree: upper airways, small airways (bronchioles), or the most distal alveoli. In this approach, a soluble liquid plug of very small volume (<1 mL) is instilled into the upper airways, and with programmed air ventilation of the lungs, the plug is pushed into a specific desired (more distal) airway to achieve deposition of liquid film onto the lung epithelium. The plug volume and ventilation conditions were determined by mathematical modeling of plug transport in a tubular geometry, and targeted liquid film deposition was demonstrated in rat lungs by three different in vivo imaging modalities. The experimental and modeling data suggest that instillation of microvolumes of liquid into a ventilated pulmonary airway could be an effective strategy to deliver exact doses of drugs to targeted pathologic regions of the lung, especially those inaccessible by bronchoscopy, to increase in situ efficacy of the drug and minimize systemic side effects.
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A Pipeline for Screening Small Molecules with Growth Inhibitory Activity against Burkholderia cenocepacia. PLoS One 2015; 10:e0128587. [PMID: 26053039 PMCID: PMC4460083 DOI: 10.1371/journal.pone.0128587] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/28/2015] [Indexed: 12/02/2022] Open
Abstract
Infections with the bacteria Burkholderia cepacia complex (Bcc) are very difficult to eradicate in cystic fibrosis patients due the intrinsic resistance of Bcc to most available antibiotics and the emergence of multiple antibiotic resistant strains during antibiotic treatment. In this work, we used a whole-cell based assay to screen a diverse collection of small molecules for growth inhibitors of a relevant strain of Bcc, B. cenocepacia K56-2. The primary screen used bacterial growth in 96-well plate format and identified 206 primary actives among 30,259 compounds. From 100 compounds with no previous record of antibacterial activity secondary screening and data mining selected a total of Bce bioactives that were further analyzed. An experimental pipeline, evaluating in vitro antibacterial and antibiofilm activity, toxicity and in vivo antibacterial activity using C. elegans was used for prioritizing compounds with better chances to be further investigated as potential Bcc antibacterial drugs. This high throughput screen, along with the in vitro and in vivo analysis highlights the utility of this experimental method to quickly identify bioactives as a starting point of antibacterial drug discovery.
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Gautam V, Shafiq N, Singh M, Ray P, Singhal L, Jaiswal NP, Prasad A, Singh S, Agarwal A. Clinical and in vitro evidence for the antimicrobial therapy in Burkholderia cepacia complex infections. Expert Rev Anti Infect Ther 2015; 13:629-63. [PMID: 25772031 DOI: 10.1586/14787210.2015.1025056] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Treatment of infections caused by Burkholderia cepacia complex (Bcc) in cystic fibrosis (CF) patients poses a complex problem. Bcc is multidrug-resistant due to innate and acquired mechanisms of resistance. As CF patients receive multiple courses of antibiotics, susceptibility patterns of strains from CF patients may differ from those noted in strains from non-CF patients. Thus, there was a need for assessing in vitro and clinical data to guide antimicrobial therapy in these patients. A systematic search of literature, followed by extraction and analysis of available information from human and in vitro studies was done. The results of the analysis are used to address various aspects like use of antimicrobials for pulmonary and non-pulmonary infections, use of combination versus monotherapy, early eradication, duration of therapy, route of administration, management of biofilms, development of resistance during therapy, pharmacokinetics-pharmacodynamics correlations, therapy in post-transplant patients and newer drugs in Bcc-infected CF patients.
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Affiliation(s)
- Vikas Gautam
- Deparatment of Medical Microbiology, PGIMER, Chandigarh 160022, India
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Craig RA, McCoy CP, Gorman SP, Jones DS. Photosensitisers - the progression from photodynamic therapy to anti-infective surfaces. Expert Opin Drug Deliv 2014; 12:85-101. [PMID: 25247277 DOI: 10.1517/17425247.2015.962512] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The application of light as a stimulus in pharmaceutical systems and the associated ability to provide precise spatiotemporal control over location, wavelength and intensity, allowing ease of external control independent of environmental conditionals, has led to its increased use. Of particular note is the use of light with photosensitisers. AREAS COVERED Photosensitisers are widely used in photodynamic therapy to cause a cidal effect towards cells on irradiation due to the generation of reactive oxygen species. These cidal effects have also been used to treat infectious diseases. The effects and benefits of photosensitisers in the treatment of such conditions are still being developed and further realised, with the design of novel delivery strategies. This review provides an overview of the realisation of the pharmaceutically relevant uses of photosensitisers, both in the context of current research and in terms of current clinical application, and looks to the future direction of research. EXPERT OPINION Substantial advances have been and are being made in the use of photosensitisers. Of particular note are their antimicrobial applications, due to absence of resistance that is so frequently associated with conventional treatments. Their potency of action and the ability to immobilise to polymeric supports is opening a wide range of possibilities with great potential for use in healthcare infection prevention strategies.
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Affiliation(s)
- Rebecca A Craig
- Queen's University Belfast, School of Pharmacy , 97 Lisburn Road, Belfast, BT9 7BL , UK
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28
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Rubin BK, Williams RW. Aerosolized Antibiotics for Non-Cystic Fibrosis Bronchiectasis. Respiration 2014; 88:177-84. [DOI: 10.1159/000366000] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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JIANG HONG, LI JICHANG, ZHOU TIEZHONG, WANG CHUNHUA, ZHANG HUA, WANG HONGJUN. Colistin-induced apoptosis in PC12 cells: Involvement of the mitochondrial apoptotic and death receptor pathways. Int J Mol Med 2014; 33:1298-304. [DOI: 10.3892/ijmm.2014.1684] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/28/2014] [Indexed: 11/06/2022] Open
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Adam P, Czapiewski P, Colak S, Kosmidis P, Tousseyn T, Sagaert X, Boudova L, Okoń K, Morresi-Hauf A, Agostinelli C, Pileri S, Pruneri G, Martinelli G, Du MQ, Fend F. Prevalence ofAchromobacter xylosoxidansin pulmonary mucosa-associated lymphoid tissue lymphoma in different regions of Europe. Br J Haematol 2013; 164:804-10. [DOI: 10.1111/bjh.12703] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 11/01/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Patrick Adam
- Institute of Pathology; University of Tübingen; Tübingen Germany
| | - Piotr Czapiewski
- Department of Pathomorphology; Medical University of Gdansk; Gdansk Poland
| | - Seba Colak
- Institute of Pathology; University of Tübingen; Tübingen Germany
| | | | - Thomas Tousseyn
- KU Leuven; Translational Cell and Tissue Research; Leuven Belgium
| | - Xavier Sagaert
- KU Leuven; Translational Cell and Tissue Research; Leuven Belgium
| | - Ludmila Boudova
- Department of Pathology; Medical Faculty Hospital; Charles University of Plzen; Plzen Czech Republic
| | - Krzysztof Okoń
- Institute of Pathology; Jagiellonian University Kraków; Krakow Poland
| | - Alicia Morresi-Hauf
- Institute of Pathology; Centre of Pneumology and CTC Surgery; Asklepios Hospital; Gauting Germany
| | - Claudio Agostinelli
- Unità Operativa di Emolinfopatologia; Università degli Studi di Bologna; Bologna Italy
| | - Stefano Pileri
- Unità Operativa di Emolinfopatologia; Università degli Studi di Bologna; Bologna Italy
| | | | | | - Ming-Qing Du
- Division of Molecular Histopathology; Department of Pathology; University of Cambridge; Cambridge UK
| | - Falko Fend
- Institute of Pathology; University of Tübingen; Tübingen Germany
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Antibacterial efficacy of temperate phage-mediated inhibition of bacterial group motilities. Antimicrob Agents Chemother 2012; 56:5612-7. [PMID: 22908158 DOI: 10.1128/aac.00504-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Phage therapy against bacterial pathogens has been resurrected as an alternative and supplementary anti-infective modality. Here, we observed that bacterial group motilities were impaired in Pseudomonas aeruginosa strain PA14 lysogens for some temperate siphophages; the PA14 lysogens for DMS3 and MP22 were impaired in swarming motility, whereas the PA14 lysogen for D3112 was impaired in twitching motility. The swarming and twitching motilities of PA14 were also affected in the presence of MP22 and D3112, respectively. The in vitro killing activities of D3112 and MP22 toward PA14 did not differ, and neither did their in vivo persistence in the absence of bacterial infections in mice as well as in flies. Nevertheless, administration of D3112, not MP22, significantly reduced the mortality and the bacterial burdens in murine peritonitis-sepsis and Drosophila systemic infection caused by PA14. Taken together, we suggest that a temperate phage-mediated twitching motility inhibition might be comparably effective to control the acute infections caused by P. aeruginosa.
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Florescu DF, Qiu F, McCartan MA, Mindru C, Fey PD, Kalil AC. What is the efficacy and safety of colistin for the treatment of ventilator-associated pneumonia? A systematic review and meta-regression. Clin Infect Dis 2012; 54:670-80. [PMID: 22322268 DOI: 10.1093/cid/cir934] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Experience with intravenous and aerosolized forms of colistin for the treatment of ventilator-associated pneumonia (VAP) in patients without cystic fibrosis is limited. We aimed to assess the safety and efficacy of colistin for the treatment of VAP. METHODS We searched MEDLINE and Cochrane Database of Systematic Reviews for studies comparing colistin vs other antibiotics for treatment of VAP in patients without cystic fibrosis. QUOROM guidelines were followed, the I(2) method was used for heterogeneity, and a random-effects model for odds ratio (OR) estimates. RESULTS Six controlled studies met the inclusion criteria. Clinical response did not differ significantly between colistin and control groups (OR, 1.14; 95% confidence interval [CI], .74-1.77; P = .56; I(2) = 0%). The efficacy of colistin was independent of study design (prospective OR, 0.89 [95% CI, .48-1.66; P = .71; I(2) = 0%]; retrospective OR, 1.45 [95% CI, .79-2.68; P = .23; I(2) = 0%]); randomized trials OR, 0.86 [95% CI, .43-1.74; P = .68; I(2) = 0%]). There was no indication of a significant change in clinical response after controlling for concomitant antibiotic treatment (intercept, 0.121; slope, 0.0315; P = .95). Treatment with colistin vs controls did not affect hospital mortality (OR, 0.92; 95% CI, .50-1.67; P = .78; I(2) = 34.59%) or nephrotoxicity (OR, 1.14; 95% CI, .59-2.20; P = .69; I(2) = 0%). Fourteen single-arm studies have been analyzed, and the results were in concordance with the findings of the controlled studies. CONCLUSIONS Our results suggest that colistin may be as safe and as efficacious as standard antibiotics for the treatment of VAP.
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Affiliation(s)
- Diana F Florescu
- Infectious Diseases Division, Nebraska Medical Center, Omaha, NE 68198-5400, USA.
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Elangovan T, George RP, Kuppusami P, Mangalaraj D, Bera S, Mohandas E, Kim DE. Development of a CrN/Cu nanocomposite coating on titanium-modified stainless steel for antibacterial activity against Pseudomonas aeruginosa. BIOFOULING 2012; 28:779-787. [PMID: 22827159 DOI: 10.1080/08927014.2012.710605] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A relatively simple method was developed to fabricate CrN/Cu nanocomposite coatings using pulsed DC magnetron sputtering for application in antibacterial activity. These nanocomposite coatings were applied on titanium (Ti)-modified stainless steel substrata (D-9 alloy) and the antibacterial activity of these coating with respect to the Gram-negative bacterium Pseudomonas aeruginosa was investigated qualitatively and quantitatively. Scanning electron microscopy, epifluorescence microscope analyses, and total viable counts confirmed that inclusion of copper in the CrN/Cu nanocomposite coatings provided antibacterial activity against P. aeruginosa. The quantitative examination of the bacterial activity of P. aeruginosa was estimated by the survival ratio as calculated from the number of viable cells which formed colonies on nutrient agar plates.
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Affiliation(s)
- T Elangovan
- Department of Physics, Bharathiar University, Coimbatore, India
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Kempf M, Rolain JM. Emergence of resistance to carbapenems in Acinetobacter baumannii in Europe: clinical impact and therapeutic options. Int J Antimicrob Agents 2011; 39:105-14. [PMID: 22113193 DOI: 10.1016/j.ijantimicag.2011.10.004] [Citation(s) in RCA: 248] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 10/10/2011] [Indexed: 12/31/2022]
Abstract
Despite having a reputation of low virulence, Acinetobacter baumannii is an emerging multidrug-resistant (MDR) pathogen responsible for community- and hospital-acquired infections that are difficult to control and treat. Interest in this pathogen emerged about one decade ago because of its natural MDR phenotype, its capability of acquiring new mechanisms of resistance and the existence of nosocomial outbreaks. Recent advances in molecular biology, including full genome sequencing of several A. baumannii isolates, has led to the discovery of the extraordinary plasticity of their genomes, which is linked to their great propensity to adapt to any environment, including hospitals. In this context, as well as the increasing antimicrobial resistance amongst A. baumannii isolates to the last-line antibiotics carbapenems and colistin, therapeutic options are very limited or absent in some cases of infections with pandrug-resistant bacteria. However, a large proportion of patients may be colonised by such MDR bacteria without any sign of infection, leading to a recurrent question for clinicians as to whether antibiotic treatment should be given and will be effective in the presence of resistance mechanisms. The worldwide emergence of A. baumannii strains resistant to colistin is worrying and the increasing use of colistin to treat infections caused by MDR bacteria will inevitably increase the recovery rate of colistin-resistant isolates in the future. Current knowledge about A. baumannii, including biological and epidemiological aspects as well as resistance to antibiotics and antibiotic therapy, are reviewed in this article, in addition to therapeutic recommendations.
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Affiliation(s)
- Marie Kempf
- Aix-Marseille University, URMITE CNRS-IRD, UMR 6236, Faculté de Médecine et de Pharmacie, Université de Méditerranée, 27 Bd. Jean Moulin, 13385 Marseille cedex 05, France
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Photodynamic Antimicrobial Chemotherapy (PACT) in combination with antibiotics for treatment of Burkholderia cepacia complex infection. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 106:95-100. [PMID: 22079165 DOI: 10.1016/j.jphotobiol.2011.10.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 10/07/2011] [Accepted: 10/25/2011] [Indexed: 11/23/2022]
Abstract
This study aimed to determine if Photodynamic Antimicrobial Chemotherapy (PACT) was effective in the treatment of Burkholderia cepacia complex infection and whether a synergistic effect was evident if PACT was used in combination with antibiotics. The susceptibility of both planktonic and biofilm cultures of B. cepacia complex strains to methylene blue (MB) and meso-tetra(n-methyl-4-pyridyl)porphine tetra-tosylate (TMP)-mediated PACT was determined alone and in combination with antibiotics used in the treatment of Cystic Fibrosis pulmonary infection caused by these bacteria. When B. cepacia complex strains were grown planktonically, high levels of kill of were achieved with both TMP and MB-mediated PACT with strain and photosensitizer specific differences apparent. When strains were grown in biofilm, antibiotic treatment alone was bactericidal in 17/36 (47%) strain/antibiotic combinations tested. When antibiotic treatment was combined with PACT, bactericidal activity was apparent for 33/36 (92%) strain/antibiotic combinations. No antagonism was detected between PACT and antibiotic treatment with the combination synergistic for 6/36 (17%) and indifferent for 30/36 (83%) strain/antibiotic combinations. PACT could be a viable treatment option, either alone or in combination with antibiotics for treatment of B. cepacia complex pulmonary infection.
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Bien J, Sokolova O, Bozko P. Characterization of Virulence Factors of Staphylococcus aureus: Novel Function of Known Virulence Factors That Are Implicated in Activation of Airway Epithelial Proinflammatory Response. J Pathog 2011; 2011:601905. [PMID: 22567334 PMCID: PMC3335658 DOI: 10.4061/2011/601905] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 06/23/2011] [Accepted: 07/15/2011] [Indexed: 12/04/2022] Open
Abstract
Airway epithelial cells play a major role in initiating inflammation in response to bacterial pathogens. S. aureus is an important pathogen associated with activation of diverse types of infection characterized by inflammation dominated by polymorphonuclear leukocytes. This bacterium frequently causes lung infection, which is attributed to virulence factors. Many of virulence determinants associated with S. aureus-mediated lung infection have been known for several years. In this paper, we discuss recent advances in our understanding of known virulence factors implicated in pneumonia. We anticipate that better understanding of novel functions of known virulence factors could open the way to regulate inflammatory reactions of the epithelium and to develop effective strategies to treat S. aureus-induced airway diseases.
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Affiliation(s)
- Justyna Bien
- Witold Stefanski Institute of Parasitology of the Polish Academy of Sciences, Twarda Street 51/55, 00-818 Warsaw, Poland
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Pollini S, Fiscarelli E, Mugnaioli C, Di Pilato V, Ricciotti G, Neri AS, Rossolini GM. Pseudomonas aeruginosa infection in cystic fibrosis caused by an epidemic metallo-β-lactamase-producing clone with a heterogeneous carbapenem resistance phenotype. Clin Microbiol Infect 2011; 17:1272-5. [PMID: 21375657 DOI: 10.1111/j.1469-0691.2011.03466.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An epidemic IMP-13 metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa clone, causing infections and even large outbreaks in Italian critical care settings, was detected in a young cystic fibrosis patient. In this patient, the chronic infection was sustained by distinct clonal sub-populations of the MBL-producing P. aeruginosa clone, either susceptible or resistant to carbapenems. These findings underscore the importance of infection prevention practices in cystic fibrosis settings and pose an important diagnostic and therapeutic challenge.
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Affiliation(s)
- S Pollini
- Università degli Studi di Siena, Siena, Italy
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Moazeni E, Gilani K, Sotoudegan F, Pardakhty A, Najafabadi AR, Ghalandari R, Fazeli MR, Jamalifar H. Formulation and in vitro evaluation of ciprofloxacin containing niosomes for pulmonary delivery. J Microencapsul 2011; 27:618-27. [PMID: 20681747 DOI: 10.3109/02652048.2010.506579] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In order to develop a niosome-encapsulated ciprofloxacin (CPFX) HCl formulation for pulmonary delivery, the feasibility of encapsulation of CPFX in niosomes, its stability and nebulization capability was evaluated. Various combinations of nonionic surfactants with cholesterol were used to prepare the formulations. The in vitro deposition data of the niosomal formulations were examined using an Andersen cascade impactor. Formulations composed of Span 60 and Tween 60 in combination with 40 mol% of cholesterol exhibited high encapsulation efficacy and stability and also had fine particle fraction and nebulization efficiency of about 61.9% ± 1.0 and 77.9 ± 2.8, respectively. Minimal inhibitory concentration of the niosomal CPFX against some pulmonary pathogens were lower than free CPFX. Using the MTT assay in human lung carcinoma cell line (A549), niosome-entrapped CPFX showed significantly lower cytotoxicity in comparison to the free drug. These results indicate that niosome can be used as a carrier for pulmonary delivery of CPFX via nebulization.
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Affiliation(s)
- Esmaeil Moazeni
- Aerosol Research Laboratory, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
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Kuang Z, Hao Y, Hwang S, Zhang S, Kim E, Akinbi HT, Schurr MJ, Irvin RT, Hassett DJ, Lau GW. The Pseudomonas aeruginosa flagellum confers resistance to pulmonary surfactant protein-A by impacting the production of exoproteases through quorum-sensing. Mol Microbiol 2011; 79:1220-35. [PMID: 21205009 DOI: 10.1111/j.1365-2958.2010.07516.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Surfactant protein-A (SP-A) is an important antimicrobial protein that opsonizes and permeabilizes membranes of microbial pathogens in mammalian lungs. Previously, we have shown that Pseudomonas aeruginosa flagellum-deficient mutants are preferentially cleared in the lungs of wild-type mice by SP-A-mediated membrane permeabilization, and not by opsonization. In this study, we report a flagellum-mediated mechanism of P. aeruginosa resistance to SP-A. We discovered that flagellum-deficient (ΔfliC) bacteria are unable to produce adequate amounts of exoproteases to degrade SP-A in vitro and in vivo, leading to its preferential clearance in the lungs of SP-A(+/+) mice. In addition, ΔfliC bacteria failed to degrade another important lung antimicrobial protein lysozyme. Detailed analyses showed that ΔfliC bacteria are unable to upregulate the transcription of lasI and rhlI genes, impairing the production of homoserine lactones necessary for quorum-sensing, an important virulence process that regulates the production of multiple exoproteases. Thus, reduced ability of ΔfliC bacteria to quorum-sense attenuates production of exoproteases and limits degradation of SP-A, thereby conferring susceptibility to this major pulmonary host defence protein.
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Affiliation(s)
- Zhizhou Kuang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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Emergence of Pseudomonas aeruginosa strains producing high levels of persister cells in patients with cystic fibrosis. J Bacteriol 2010; 192:6191-9. [PMID: 20935098 DOI: 10.1128/jb.01651-09] [Citation(s) in RCA: 431] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The majority of cystic fibrosis (CF) patients succumb to a chronic infection of the airway with Pseudomonas aeruginosa. Paradoxically, pathogenic strains are often susceptible to antibiotics, but the infection cannot be eradicated with antimicrobial therapy. We find that in a majority of patients with airway infections, late isolates of P. aeruginosa produce increased levels of drug-tolerant persister cells. The genomes of a clonal pair of early/late isolates from a single patient have been previously sequenced, and the late isolate (obtained at age 96 months) showed a 100-fold increase in persister levels. The 96-month isolate carries a large number of mutations, including a mutation in mutS that confers a hypermutator phenotype. There is also a mutation in the mexZ repressor controlling the expression of the MexXY-OprM multidrug pump, which results in a moderate increase in the ofloxacin, carbenicillin, and tobramycin MICs. Knocking out the mexXY locus restored the resistance to that of the parent strain but did not affect the high levels of persisters formed by the 96-month isolate. This suggests that the late isolate is a high-persister (hip) mutant. Increased persister formation was observed in exponential phase, stationary phase, and biofilm populations of the 96-month isolate. Analysis of late isolates from 14 additional patients indicated that 10 of them are hip mutants. Most of these hip mutants did not have higher drug resistance. Increased persister formation appears to be their sole mechanism for surviving chemotherapy. Taken together, these findings suggest a link between persisters and recalcitrance of CF infection and identify an overlooked culprit-high-persister mutants producing elevated levels of drug-tolerant cells. Persisters may play a similarly critical role in the recalcitrance of other chronic infections.
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Fermeiro J, Reis P, Castanhinha S, Pereira L, Barreto C. Colonização por Staphylococcus aureus resistente à meticilina: Que impacto na morbilidade de doentes pediátricos com fibrose quística? REVISTA PORTUGUESA DE PNEUMOLOGIA 2010. [DOI: 10.1016/s0873-2159(15)30050-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Metagenomic analysis of apple orchard soil reveals antibiotic resistance genes encoding predicted bifunctional proteins. Appl Environ Microbiol 2010; 76:4396-401. [PMID: 20453147 DOI: 10.1128/aem.01763-09] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To gain insight into the diversity and origins of antibiotic resistance genes, we identified resistance genes in the soil in an apple orchard using functional metagenomics, which involves inserting large fragments of foreign DNA into Escherichia coli and assaying the resulting clones for expressed functions. Among 13 antibiotic-resistant clones, we found two genes that encode bifunctional proteins. One predicted bifunctional protein confers resistance to ceftazidime and contains a natural fusion between a predicted transcriptional regulator and a beta-lactamase. Sequence analysis of the entire metagenomic clone encoding the predicted bifunctional beta-lactamase revealed a gene potentially involved in chloramphenicol resistance as well as a predicted transposase. A second clone that encodes a predicted bifunctional protein confers resistance to kanamycin and contains an aminoglycoside acetyltransferase domain fused to a second acetyltransferase domain that, based on nucleotide sequence, was predicted not to be involved in antibiotic resistance. This is the first report of a transcriptional regulator fused to a beta-lactamase and of an aminoglycoside acetyltransferase fused to an acetyltransferase not involved in antibiotic resistance.
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Weadge JT, Yip PP, Robinson H, Arnett K, Tipton PA, Howell PL. Expression, purification, crystallization and preliminary X-ray analysis of Pseudomonas aeruginosa AlgX. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:588-91. [PMID: 20445266 PMCID: PMC2864699 DOI: 10.1107/s1744309110011851] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 03/29/2010] [Indexed: 11/10/2022]
Abstract
AlgX is a periplasmic protein required for the production of the exopolysaccharide alginate in Pseudomonas sp. and Azotobacter vinelandii. AlgX has been overexpressed and purified and diffraction-quality crystals have been grown using iterative seeding and the hanging-drop vapor-diffusion method. The crystals grew as flat plates with unit-cell parameters a = 46.4, b = 120.6, c = 86.9 A, beta = 95.7 degrees . The crystals exhibited the symmetry of space group P2(1) and diffracted to a minimum d-spacing of 2.1 A. On the basis of the Matthews coefficient (V(M) = 2.25 A(3) Da(-1)), two molecules were estimated to be present in the asymmetric unit.
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Affiliation(s)
- Joel T. Weadge
- Program in Molecular Structure and Function, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Patrick P. Yip
- Program in Molecular Structure and Function, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Howard Robinson
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - Krista Arnett
- Department of Biochemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | - Peter A. Tipton
- Department of Biochemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | - P. Lynne Howell
- Program in Molecular Structure and Function, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Construction of aminoglycoside-sensitive Burkholderia cenocepacia strains for use in studies of intracellular bacteria with the gentamicin protection assay. Appl Environ Microbiol 2010; 76:3170-6. [PMID: 20348312 DOI: 10.1128/aem.03024-09] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Burkholderia cenocepacia is a multidrug-resistant opportunistic pathogen that infects the airways of patients with cystic fibrosis (CF) and can survive intracellularly in macrophages and epithelial cells. The gentamicin protection assay, which relies on the poor ability of gentamicin or other aminoglycosides to permeate eukaryotic cell membranes, is traditionally employed to quantify intracellular bacteria. However, the high resistance of these bacteria to aminoglycosides hampers the use of the gentamicin protection assay to investigate intracellular infection by B. cenocepacia. Here, we report the construction of gentamicin-sensitive strains of B. cenocepacia carrying a deletion of the BCAL1674, BCAL1675, and BCAL1676 genes that form an operon encoding an AmrAB-OprA-like efflux pump. We show that bacteria carrying this deletion are hypersensitive to gentamicin and also delay phagolysosomal fusion upon infection of RAW 264.7 murine macrophages, as previously demonstrated for the parental strain. We also demonstrate for the first time that low concentrations of gentamicin can be used to effectively kill extracellular bacteria and reliably quantify the intracellular infection by B. cenocepacia, which can replicate in RAW 264.7 macrophages.
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Allen HK, Donato J, Wang HH, Cloud-Hansen KA, Davies J, Handelsman J. Call of the wild: antibiotic resistance genes in natural environments. Nat Rev Microbiol 2010; 8:251-9. [DOI: 10.1038/nrmicro2312] [Citation(s) in RCA: 1411] [Impact Index Per Article: 100.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Hare NJ, Cordwell SJ. Proteomics of bacterial pathogens: Pseudomonas aeruginosa infections in cystic fibrosis - a case study. Proteomics Clin Appl 2010; 4:228-48. [PMID: 21137046 DOI: 10.1002/prca.200900144] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 09/09/2009] [Accepted: 09/30/2009] [Indexed: 12/20/2022]
Abstract
Technology development in the high throughput sciences of genomics, transcriptomics and proteomics, has been driven by bacteriological research. These organisms are excellent models for testing new methodology due to their comparatively small genome size, the relative ease of culturing large amounts of material, and the inherent biomedical, environmental and biotechnological interest in their underlying biology. Techniques developed in prokaryotes have since become applicable to higher organisms and human disease, opening vast research opportunities for understanding complex molecular processes. Pseudomonas aeruginosa is an excellent example of a microbe with fascinating properties suitable for stretching the boundaries of technology, and with underlying biology that remains poorly understood. P. aeruginosa is an opportunistic pathogen in humans and contains one of the largest genetic capabilities for a single-celled organism (approximately 5500 genes), which allows it to encode a wide variety of surface-associated and secreted virulence factors, as well as adapt to harsh environments, forming resistance to an array of antibacterial agents. While it is a major threat as a nosocomial pathogen, and particularly in the immunocompromised, it is also the most significant cause of mortality in patients suffering from the genetic disorder, cystic fibrosis. This review examines the role of proteomics in gaining a better understanding of the molecular basis of P. aeruginosa infection and persistence in the lungs of cystic fibrosis patients.
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Affiliation(s)
- Nathan J Hare
- School of Molecular and Microbial Biosciences, The University of Sydney, Sydney, Australia
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Pompilio A, Catavitello C, Picciani C, Confalone P, Piccolomini R, Savini V, Fiscarelli E, D'Antonio D, Di Bonaventura G. Subinhibitory concentrations of moxifloxacin decrease adhesion and biofilm formation of Stenotrophomonas maltophilia from cystic fibrosis. J Med Microbiol 2010; 59:76-81. [DOI: 10.1099/jmm.0.011981-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stenotrophomonas maltophilia is an emerging nosocomial bacterial pathogen that is currently isolated with increasing frequency from the airways of cystic fibrosis (CF) patients. In this study the effect of subinhibitory concentrations (subMICs) of moxifloxacin on adhesion, biofilm formation and cell-surface hydrophobicity of two strains of S. maltophilia isolated from CF patients were evaluated. Adhesion and biofilm formation assays were carried out on polystyrene and quantified by colony counts. Cell-surface hydrophobicity was determined by a test for adhesion to n-hexadecane. Moxifloxacin at 0.03× and 0.06× MIC caused a significant decrease in adhesion and biofilm formation by both strains tested. A significant reduction in cell-surface hydrophobicity following exposure to subMICs of moxifloxacin was observed for one strain only. The results of the present study provide an additional rationale for the use of moxifloxacin in CF patients and more generally in biofilm-related infections involving S. maltophilia.
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Affiliation(s)
- A. Pompilio
- Center for Excellence on Aging, ‘G. D’Annunzio’ University Foundation, Chieti, Italy
- Clinical Microbiology Unit, Department of Biomedical Sciences, ‘G. D’Annunzio’ University of Chieti-Pescara, Chieti, Italy
| | - C. Catavitello
- Clinical Microbiology and Virology Unit, Department of Transfusion Medicine, ‘Spirito Santo’ Hospital, Pescara, Italy
| | - C. Picciani
- Center for Excellence on Aging, ‘G. D’Annunzio’ University Foundation, Chieti, Italy
- Clinical Microbiology Unit, Department of Biomedical Sciences, ‘G. D’Annunzio’ University of Chieti-Pescara, Chieti, Italy
| | - P. Confalone
- Center for Excellence on Aging, ‘G. D’Annunzio’ University Foundation, Chieti, Italy
- Clinical Microbiology Unit, Department of Biomedical Sciences, ‘G. D’Annunzio’ University of Chieti-Pescara, Chieti, Italy
| | - R. Piccolomini
- Center for Excellence on Aging, ‘G. D’Annunzio’ University Foundation, Chieti, Italy
- Clinical Microbiology Unit, Department of Biomedical Sciences, ‘G. D’Annunzio’ University of Chieti-Pescara, Chieti, Italy
| | - V. Savini
- Clinical Microbiology and Virology Unit, Department of Transfusion Medicine, ‘Spirito Santo’ Hospital, Pescara, Italy
| | - E. Fiscarelli
- Laboratory of Clinical Microbiology, ‘Bambino Gesù’ Pediatric Hospital, Rome, Italy
| | - D. D'Antonio
- Clinical Microbiology and Virology Unit, Department of Transfusion Medicine, ‘Spirito Santo’ Hospital, Pescara, Italy
| | - G. Di Bonaventura
- Center for Excellence on Aging, ‘G. D’Annunzio’ University Foundation, Chieti, Italy
- Clinical Microbiology Unit, Department of Biomedical Sciences, ‘G. D’Annunzio’ University of Chieti-Pescara, Chieti, Italy
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MacLeod DL, Barker LM, Sutherland JL, Moss SC, Gurgel JL, Kenney TF, Burns JL, Baker WR. Antibacterial activities of a fosfomycin/tobramycin combination: a novel inhaled antibiotic for bronchiectasis. J Antimicrob Chemother 2009; 64:829-36. [PMID: 19679597 PMCID: PMC2740636 DOI: 10.1093/jac/dkp282] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Objectives To compare the in vitro and in vivo activities of a 4:1 (w/w) fosfomycin/tobramycin combination (FTI) with those of fosfomycin and tobramycin alone against cystic fibrosis (CF) and non-CF bronchiectasis pathogens. Methods Clinical isolates of CF Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenzae, Stenotrophomonas maltophilia, Burkholderia cepacia complex, Escherichia coli and Klebsiellia spp. were evaluated by MIC, MBC, post-antibiotic effect (PAE), synergy, time–kill, a rat pneumonia model and spontaneous mutation frequency (SMF). Results FTI showed high activity against E. coli, H. influenzae, S. aureus and Klebsiella spp. For the S. aureus strains, 75% of which were methicillin resistant (MRSA), FTI had a lower MIC90 than tobramycin. For P. aeruginosa, FTI had a lower MIC90 than fosfomycin, but tobramycin was more active than either. Synergy studies showed no antagonism between fosfomycin and tobramycin, and 93% of the isolates demonstrated no interaction. FTI was rapidly bactericidal and exhibited concentration-dependent killing in time–kill studies. In the rat pneumonia model, FTI and tobramycin demonstrated bactericidal killing of P. aeruginosa; both were more active than fosfomycin alone. The SMF for S. aureus resistance to FTI was 2–4 log10 lower than that for tobramycin and 2–7 log10 lower than that for fosfomycin. For P. aeruginosa, the FTI SMF was 2–3 log10 lower than that for fosfomycin and 1–2 log10 lower than that for tobramycin. Conclusions FTI is a broad-spectrum antibiotic combination with high activity in vitro and in vivo. These data suggest FTI could be a potential treatment for respiratory infections caused by Gram-positive and Gram-negative aerobic bacteria.
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Flagellum-mediated biofilm defense mechanisms of Pseudomonas aeruginosa against host-derived lactoferrin. Infect Immun 2009; 77:4559-66. [PMID: 19651866 DOI: 10.1128/iai.00075-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chronic infection with the gram-negative organism Pseudomonas aeruginosa is a leading cause of morbidity and mortality in human patients, despite high doses of antibiotics used to treat the various diseases this organism causes. These infections are chronic because P. aeruginosa readily forms biofilms, which are inherently resistant to antibiotics as well as the host's immune system. Our laboratory has been investigating specific mutations in P. aeruginosa that regulate biofilm bacterial susceptibility to the host. To continue our investigation of the role of genetics in bacterial biofilm host resistance, we examined P. aeruginosa biofilms that lack the flgK gene. This mutant lacks flagella, which results in defects in early biofilm development (up to 36 h). For these experiments, the flgK-disrupted strain and the parental strain (PA14) were used in a modified version of the 96-well plate microtiter assay. Biofilms were challenged with freshly isolated human leukocytes for 4 to 6 h and viable bacteria enumerated by CFU. Subsequent to the challenge, both mononuclear cells (monocytes and lymphocytes) and neutrophils, along with tumor necrosis factor alpha (TNF-alpha), were required for optimal killing of the flgK biofilm bacteria. We identified a cytokine cross talk network between mononuclear cells and neutrophils that was essential to the production of lactoferrin and bacterial killing. Our data suggest that TNF-alpha is secreted from mononuclear cells, causing neutrophil activation, resulting in the secretion of bactericidal concentrations of lactoferrin. These results extend previous studies of the importance of lactoferrin in the innate immune defense against bacterial biofilms.
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Nasnas R, Saliba G, Hallak P. The revival of colistin: An old antibiotic for the 21st century. ACTA ACUST UNITED AC 2009; 57:229-35. [DOI: 10.1016/j.patbio.2007.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2007] [Accepted: 09/19/2007] [Indexed: 10/22/2022]
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