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Szymczak K, Woźniak-Pawlikowska A, Burzyńska N, Król M, Zhang L, Nakonieczna J, Grinholc M. Decrease of ESKAPE virulence with a cationic heme-mimetic gallium porphyrin photosensitizer: The Trojan horse strategy that could help address antimicrobial resistance. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 256:112928. [PMID: 38723545 DOI: 10.1016/j.jphotobiol.2024.112928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 04/25/2024] [Accepted: 04/30/2024] [Indexed: 06/11/2024]
Abstract
INTRODUCTION Emerging antibiotic resistance among bacterial pathogens has forced an urgent need for alternative non-antibiotic strategies development that could combat drug resistant-associated infections. Suppression of virulence of ESKAPE pathogens' by targeting multiple virulence traits provides a promising approach. OBJECTIVES Here we propose an iron-blocking antibacterial therapy based on a cationic heme-mimetic gallium porphyrin (GaCHP), which antibacterial efficacy could be further enhanced by photodynamic inactivation. METHODS We used gallium heme mimetic porphyrin (GaCHP) excited with light to significantly reduce microbial viability and suppress both the expression and biological activity of several virulence traits of both Gram-positive and Gram-negative ESKAPE representatives, i.e., S. aureus and P. aeruginosa. Moreover, further improvement of the proposed strategy by combining it with routinely used antimicrobials to resensitize the microbes to antibiotics and provide enhanced bactericidal efficacy was investigated. RESULTS The proposed strategy led to substantial inactivation of critical priority pathogens and has been evidenced to suppress the expression and biological activity of multiple virulence factors in S. aureus and P. aeruginosa. Finally, the combination of GaCHP phototreatment and antibiotics resulted in promising strategy to overcome antibiotic resistance of the studied microbes and to enhance disinfection of drug resistant pathogens. CONCLUSION Lastly, considering high safety aspects of the proposed treatment toward host cells, i.e., lack of mutagenicity, no dark toxicity and mild phototoxicity, we describe an efficient alternative that simultaneously suppresses the functionality of multiple virulence factors in ESKAPE pathogens.
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Affiliation(s)
- Klaudia Szymczak
- Laboratory of Photobiology and Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland
| | - Agata Woźniak-Pawlikowska
- Laboratory of Photobiology and Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland
| | - Natalia Burzyńska
- Laboratory of Photobiology and Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland
| | - Magdalena Król
- Laboratory of Photobiology and Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland
| | - Lei Zhang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), Tianjin University, Tianjin 300350, China
| | - Joanna Nakonieczna
- Laboratory of Photobiology and Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland.
| | - Mariusz Grinholc
- Laboratory of Photobiology and Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland.
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O'Toole GA. It's time to write a minireview. J Bacteriol 2024; 206:e0011324. [PMID: 38624220 PMCID: PMC11112987 DOI: 10.1128/jb.00113-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024] Open
Affiliation(s)
- George A. O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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3
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Trognon J, Rima M, Lajoie B, Roques C, El Garah F. NaCl-induced modulation of species distribution in a mixed P. aeruginosa / S. aureus / B.cepacia biofilm. Biofilm 2023; 6:100153. [PMID: 37711514 PMCID: PMC10497989 DOI: 10.1016/j.bioflm.2023.100153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/16/2023] Open
Abstract
Pseudomonas aeruginosa, Staphylococcus aureus, and Burkholderia cepacia are notorious pathogens known for their ability to form resilient biofilms, particularly within the lung environment of cystic fibrosis (CF) patients. The heightened concentration of NaCl, prevalent in the airway liquid of CF patients' lungs, has been identified as a factor that promotes the growth of osmotolerant bacteria like S. aureus and dampens host antibacterial defenses, thereby fostering favorable conditions for infections. In this study, we aimed to investigate how increased NaCl concentrations impact the development of multi-species biofilms in vitro, using both laboratory strains and clinical isolates of P. aeruginosa, S. aureus, and B. cepacia co-cultures. Employing a low-nutrient culture medium that fosters biofilm growth of the selected species, we quantified biofilm formation through a combination of adherent CFU counts, qPCR analysis, and confocal microscopy observations. Our findings reaffirmed the challenges faced by S. aureus in establishing growth within 1:1 mixed biofilms with P. aeruginosa when cultivated in a minimal medium. Intriguingly, at an elevated NaCl concentration of 145 mM, a symbiotic relationship emerged between S. aureus and P. aeruginosa, enabling their co-existence. Notably, this hyperosmotic environment also exerted an influence on the interplay of these two bacteria with B. cepacia. We demonstrated that elevated NaCl concentrations play a pivotal role in orchestrating the distribution of these three species within the biofilm matrix. Furthermore, our study unveiled the beneficial impact of NaCl on the biofilm growth of clinically relevant mucoid P. aeruginosa strains, as well as two strains of methicillin-sensitive and methicillin-resistant S. aureus. This underscores the crucial role of the microenvironment during the colonization and infection processes. The results suggest that hyperosmotic conditions could hold the key to unlocking a deeper understanding of the genesis and behavior of CF multi-species biofilms.
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Affiliation(s)
- Jeanne Trognon
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Maya Rima
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Barbora Lajoie
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Christine Roques
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Service de Bactériologie Hygiène, Toulouse, France
| | - Fatima El Garah
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
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Suresh S, Saldanha J, Bhaskar Shetty A, Premanath R, Akhila DS, Mohan Raj JR. Comparison of Antibiofilm Activity of Pseudomonas aeruginosa Phages on Isolates from Wounds of Diabetic and Non-Diabetic Patients. Microorganisms 2023; 11:2230. [PMID: 37764074 PMCID: PMC10536433 DOI: 10.3390/microorganisms11092230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/03/2023] [Accepted: 08/15/2023] [Indexed: 09/29/2023] Open
Abstract
The persistence of organisms as biofilms and the increase in antimicrobial resistance has raised the need for alternative strategies. The study objective was to compare the ability of isolated bacteriophages to remove in vitro biofilms formed by Pseudomonas aeruginosa isolated from the environment with those isolated from diabetic and non-diabetic wounds. P. aeruginosa were isolated from clinical and environmental sites, and antimicrobial susceptibility was tested. Bacteriophages were isolated and characterized based on plaque morphology and host range. A reduction in the viable count assayed the lytic ability of candidate phages. The crystal violet method was used to determine the residual biofilm after 24 h of phage treatment on 72-h-old biofilms. The statistical significance of phage treatment was tested by one-way ANOVA. Of 35 clinical isolates, 17 showed resistance to 1 antibiotic at least, and 7 were multidrug resistant. Nineteen environmental isolates and 11 clinical isolates were drug-sensitive. Nine phages showed 91.2% host coverage, including multidrug-resistant isolates. Phages eradicated 85% of biofilms formed by environmental isolates compared to 58% of biofilms of diabetic isolates and 56% of biofilms of non-diabetic isolates. Clinical isolates are susceptible to phage infection in planktonic form. Biofilms of P. aeruginosa isolated from diabetic wounds and non-diabetic wounds resist removal by phages compared to biofilms formed by environmental isolates. All phages were efficient in dispersing PAO1 biofilms. However, there was a significant difference in their ability to disperse PAO1 biofilms across the different surfaces tested. Partial eradication of biofilm by phages can aid in complementing antibiotics that are unable to penetrate biofilms in a clinical set-up.
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Affiliation(s)
| | | | | | | | | | - Juliet Roshini Mohan Raj
- Division of Infectious Diseases, Nitte University Center for Science Education and Research, Paneer Campus, Nitte (Deemed to be University), Derelakatte, Mangaluru 575018, India (R.P.); (D.S.A.)
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5
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Charpentier LA, Dolben EF, Hendricks MR, Hogan DA, Bomberger JM, Stanton BA. Bacterial Outer Membrane Vesicles and Immune Modulation of the Host. MEMBRANES 2023; 13:752. [PMID: 37755174 PMCID: PMC10536716 DOI: 10.3390/membranes13090752] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/18/2023] [Accepted: 08/22/2023] [Indexed: 09/28/2023]
Abstract
This article reviews the role of outer membrane vesicles (OMVs) in mediating the interaction between Gram-negative bacteria and their human hosts. OMVs are produced by a diverse range of Gram-negative bacteria during infection and play a critical role in facilitating host-pathogen interactions without requiring direct cell-to-cell contact. This article describes the mechanisms by which OMVs are formed and subsequently interact with host cells, leading to the transport of microbial protein virulence factors and short interfering RNAs (sRNA) to their host targets, exerting their immunomodulatory effects by targeting specific host signaling pathways. Specifically, this review highlights mechanisms by which OMVs facilitate chronic infection through epigenetic modification of the host immune response. Finally, this review identifies critical knowledge gaps in the field and offers potential avenues for future OMV research, specifically regarding rigor and reproducibility in OMV isolation and characterization methods.
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Affiliation(s)
- Lily A. Charpentier
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (L.A.C.); (E.F.D.); (D.A.H.); (J.M.B.)
| | - Emily F. Dolben
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (L.A.C.); (E.F.D.); (D.A.H.); (J.M.B.)
| | - Matthew R. Hendricks
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA;
| | - Deborah A. Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (L.A.C.); (E.F.D.); (D.A.H.); (J.M.B.)
| | - Jennifer M. Bomberger
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (L.A.C.); (E.F.D.); (D.A.H.); (J.M.B.)
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA;
| | - Bruce A. Stanton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (L.A.C.); (E.F.D.); (D.A.H.); (J.M.B.)
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Hammers DE, Donahue DL, Tucker Z, Ashfeld BL, Ploplis VA, Castellino FJ, Lee SW. Streptolysin S targets the sodium-bicarbonate cotransporter NBCn1 to induce inflammation and cytotoxicity in human keratinocytes during Group A Streptococcal infection. Front Cell Infect Microbiol 2022; 12:1002230. [PMID: 36389147 PMCID: PMC9663810 DOI: 10.3389/fcimb.2022.1002230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/29/2022] [Indexed: 11/30/2022] Open
Abstract
Group A <i>Streptococcus</i> (GAS, <i>Streptococcus pyogenes</i>) is a Gram-positive human pathogen that employs several secreted and surface-bound virulence factors to manipulate its environment, allowing it to cause a variety of disease outcomes. One such virulence factor is Streptolysin S (SLS), a ribosomally-produced peptide toxin that undergoes extensive post-translational modifications. The activity of SLS has been studied for over 100 years owing to its rapid and potent ability to lyse red blood cells, and the toxin has been shown to play a major role in GAS virulence <i>in vivo</i>. We have previously demonstrated that SLS induces hemolysis by targeting the chloride-bicarbonate exchanger Band 3 in erythrocytes, indicating that SLS is capable of targeting host proteins to promote cell lysis. However, the possibility that SLS has additional protein targets in other cell types, such as keratinocytes, has not been explored. Here, we use bioinformatics analysis and chemical inhibition studies to demonstrate that SLS targets the electroneutral sodium-bicarbonate cotransporter NBCn1 in keratinocytes during GAS infection. SLS induces NF-κB activation and host cytotoxicity in human keratinocytes, and these processes can be mitigated by treating keratinocytes with the sodium-bicarbonate cotransport inhibitor S0859. Furthermore, treating keratinocytes with SLS disrupts the ability of host cells to regulate their intracellular pH, and this can be monitored in real time using the pH-sensitive dye pHrodo Red AM in live imaging studies. These results demonstrate that SLS is a multifunctional bacterial toxin that GAS uses in numerous context-dependent ways to promote host cell cytotoxicity and increase disease severity. Studies to elucidate additional host targets of SLS have the potential to impact the development of therapeutics for severe GAS infections.
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Affiliation(s)
- Daniel E. Hammers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States
| | - Deborah L. Donahue
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Zachary D. Tucker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Brandon L. Ashfeld
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Victoria A. Ploplis
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Francis J. Castellino
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Shaun W. Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States,*Correspondence: Shaun W. Lee,
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7
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Olofinsae SA, Adeleke OE, Ibeh BO. Occurrence of Pseudomonas lactis and Pseudomonas paralactis Amongst Non-Lactose-Fermenting Bacterial Isolates in Chickens and Their Antimicrobial Resistance Patterns. Microbiol Insights 2022; 15:11786361221130313. [PMID: 36329710 PMCID: PMC9623376 DOI: 10.1177/11786361221130313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/16/2022] [Indexed: 11/07/2022] Open
Abstract
A serious concern of public-health proportion is rising from the carriage of antibiotic resistance determinant in Non-Lactose-Fermenting Bacteria and acquisition of virulence particularly in strains that are not routinely isolated or screened from common food animals. This study investigated the resistance profile and pathogenicity potential of selected Non-Lactose-Fermenting Bacteria isolated from 18 poultry farms. In total, we investigated the antibiotic susceptibility patterns of 25 Pseudomonas lactis and 71 Pseudomonas paralactis isolated from chicken faeces by testing them against 12 antibiotics. Resistance genes borne by the selected isolates were screened by sequencing the genetic location of resistance determinants was determined by plasmid curing. The virulence potential of the studied strains was determined phenotypically. Pseudomonas lactis isolates were mostly resistant to azetronam (93%), followed by trimethoprim (90%), cefotaxime (86%) and then amoxicillin/clavulanic acid (57%), while Pseudomonas paralactis. isolates were most resistant to azetronam (94%), trimethoprim (90%), cefepime (80%), piperacillin (75%) and amoxicillin/clavulanic acid (70%). The Multiple Antibiotic Resistance Index of Pseudomonas lactis and Pseudomonas paralactis isolates respectively ranged from 0.0 to 0.8 and 0.0 to 0.9. Polymerase Chain Reaction revealed the presence of antibiotic resistance factors such as blaCTX-M, qnrS, aac (6')-lb-cr and blaSHV while plasmid curing revealed carriages of resistance determinants on Resistance Plasmid. Moreover, virulence enzymes such as alkaline protease and phospholipase C were found in 3% and 12% of Pseudomonas paralactis and Pseudomonas lactis, respectively. This study reports the first occurrence of Pseudomonas lactis and Pseudomonas paralactis strains from chicken faeces, and their antimicrobial resistance and relative virulence suggest the encroachment of food animals by the under-studied non-lactose-fermenting bacteria that should alert public health concerns.
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Affiliation(s)
- Samson A Olofinsae
- Department of Pharmaceutical
Microbiology, Faculty of Pharmacy, University of Ibadan, Nigeria,Samson A Olofinsae, Department of
Pharmaceutical, Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan,
Oyo State 200005, Nigeria.
| | - Olufemi E Adeleke
- Department of Pharmaceutical
Microbiology, Faculty of Pharmacy, University of Ibadan, Nigeria
| | - Bartholomew O Ibeh
- Department of Medical Biotechnology,
National Biotechnology Development Agency, Abuja, Nigeria
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Unravelling the Distinctive Virulence Traits and Clonal Relationship among the Pseudomonas aeruginosa Isolates from Diabetic Patients. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2022. [DOI: 10.22207/jpam.16.3.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infections with P. aeruginosa are three times more common in people with diabetes than in non-diabetic individuals. Investigations disclosing the distinguishing traits of P. aeruginosa strains to cause respiratory and wound infection in diabetics is limited. Wound swab and sputum from infected diabetic patients were used for the isolation of P. aeruginosa. The confirmed isolates were evaluated for their virulence factor production, antibiotic susceptibility, and clonal relationship. The study confirmed the increased virulence of sputum isolates characterized by their multidrug resistant nature, strong biofilm formation at 72h [(p<0.05) =0.003)] and 96h [(p<0.05) =0.002)] and elaboration of proteolytic enzymes (40.0%). Albeit the fact that wound isolates were less virulent than the sputum isolates, there was an increased siderophore production (77.0%). Nearly 90.0% of the isolates including sputum and wound were resistant to colistin. Random Amplified Polymorphic DNA analysis showed no distinct lineages of wound and sputum isolates. The study disclosed the higher prevalence of virulent P. aeruginosa in causing infection in the diabetics. No distinct lineages of the wound and sputum isolates indicated their ability to adapt to different host environments. To the best of our knowledge, this is the first study to show the difference in virulence traits among the P. aeruginosa strains isolated from sputum and wound of diabetic patients. Our study distinctly reveals the significance of periodic examination of antibiotic resistance and virulence factors of P. aeruginosa in order to recognize the possible co-regulatory mechanism involved in their expression.
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9
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Scheffler RJ, Bratton BP, Gitai Z. Pseudomonas aeruginosa clinical blood isolates display significant phenotypic variability. PLoS One 2022; 17:e0270576. [PMID: 35793311 PMCID: PMC9258867 DOI: 10.1371/journal.pone.0270576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/13/2022] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is a significant threat in healthcare settings where it deploys a wide host of virulence factors to cause disease. Many virulence-related phenotypes such as pyocyanin production, biofilm formation, and twitching motility have been implicated in causing disease in a number of hosts. In this study, we investigate these three virulence factors in a collection of 22 clinical strains isolated from blood stream infections. Despite the fact that all 22 strains caused disease and came from the same body site of different patients, they show significant variability in assays for each of the three specific phenotypes examined. There was no significant correlation between the strength of the three phenotypes across our collection, suggesting that they can be independently modulated. Furthermore, strains deficient in each of the virulence-associated phenotypes examined could be identified. To understand the genetic basis of this variability we sequenced the genomes of the 22 strains. We found that the majority of genes responsible for pyocyanin production, biofilm formation, and twitching motility were highly conserved among the strains despite their phenotypic variability, suggesting that the phenotypic variability is likely due to regulatory changes. Our findings thus demonstrate that no one lab-assayed phenotype of pyocyanin production, biofilm production, and twitching motility is necessary for a P. aeruginosa strain to cause blood stream infection and that additional factors may be needed to fully predict what strains will lead to specific human diseases.
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Affiliation(s)
- Robert J. Scheffler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland, United States of America
| | - Benjamin P. Bratton
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Department of Pathology, Immunology and Microbiology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Nashville, Tennessee, United States of America
| | - Zemer Gitai
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
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Fakhkhari P, Tajeddin E, Azimirad M, Salmanzadeh-Ahrabi S, Abdi-Ali A, Nikmanesh B, Eshrati B, Gouya MM, Owlia P, Zali MR, Alebouyeh M. Involvement of Pseudomonas aeruginosa in the occurrence of community and hospital acquired diarrhea, and its virulence diversity among the stool and the environmental samples. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2022; 32:61-71. [PMID: 32073302 DOI: 10.1080/09603123.2020.1726300] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 02/03/2020] [Indexed: 06/10/2023]
Abstract
Transmission of Pseudomonas aeruginosa along the food chain could cause gastrointestinal infections. To show this involvement, the prevalence, putative virulence genotype, and antibiotic resistance phenotype of P. aeruginosa isolates from stool of 1482 patients with community and hospital acquired diarrhea were compared with 87 isolates from the environmental samples. The results showed infection with P. aeruginosa in 3.4% of the cases, while 57.4% of vegetable samples were contaminated. Significantly higher frequency of lasB (98%), aprA (98%), exoY (98%), and exoS (90%), but lower rate of exoT (39.2%), was detected among the stool isolates. Multi-drug resistance (MDR) phenotype was detected in 25.5% and 4% of the stool and vegetable isolates, respectively. A higher rate of studied virulence genes was detected among the MDR strains vs non-MDR strains. These results indicate P. aeruginosa as a causative agent of diarrhea either among the hospitalized patients and those with community-acquired diarrhea.
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Affiliation(s)
- Parisa Fakhkhari
- Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
| | - Elahe Tajeddin
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Masoumeh Azimirad
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Ahya Abdi-Ali
- Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
| | - Bahram Nikmanesh
- Department of Medical Laboratory Sciences, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran
| | - Babak Eshrati
- Center for Communicable Disease Control, Ministry of Health and Medical Education, Tehran, Iran
| | - Mohammad Mehdi Gouya
- Center for Communicable Disease Control, Ministry of Health and Medical Education, Tehran, Iran
| | - Parviz Owlia
- Molecular Microbiology Research Center (MMRC), Shahed University, Tehran, Iran
| | - Mohammad Reza Zali
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Masoud Alebouyeh
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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11
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Rahman F, Wushur I, Malla N, Åstrand OAH, Rongved P, Winberg JO, Sylte I. Zinc-Chelating Compounds as Inhibitors of Human and Bacterial Zinc Metalloproteases. Molecules 2021; 27:molecules27010056. [PMID: 35011288 PMCID: PMC8746695 DOI: 10.3390/molecules27010056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/17/2021] [Accepted: 12/20/2021] [Indexed: 11/16/2022] Open
Abstract
Inhibition of bacterial virulence is believed to be a new treatment option for bacterial infections. In the present study, we tested dipicolylamine (DPA), tripicolylamine (TPA), tris pyridine ethylene diamine (TPED), pyridine and thiophene derivatives as putative inhibitors of the bacterial virulence factors thermolysin (TLN), pseudolysin (PLN) and aureolysin (ALN) and the human zinc metalloproteases, matrix metalloprotease-9 (MMP-9) and matrix metalloprotease-14 (MMP-14). These compounds have nitrogen or sulfur as putative donor atoms for zinc chelation. In general, the compounds showed stronger inhibition of MMP-14 and PLN than of the other enzymes, with Ki values in the lower μM range. Except for DPA, none of the compounds showed significantly stronger inhibition of the virulence factors than of the human zinc metalloproteases. TPA and Zn230 were the only compounds that inhibited all five zinc metalloproteinases with a Ki value in the lower μM range. The thiophene compounds gave weak or no inhibition. Docking indicated that some of the compounds coordinated zinc by one oxygen atom from a hydroxyl or carbonyl group, or by oxygen atoms both from a hydroxyl group and a carbonyl group, and not by pyridine nitrogen as in DPA and TPA.
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Affiliation(s)
- Fatema Rahman
- Molecular Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT—The Arctic University of Norway, NO-9037 Tromsø, Norway; (F.R.); (I.W.); (N.M.); (J.-O.W.)
| | - Imin Wushur
- Molecular Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT—The Arctic University of Norway, NO-9037 Tromsø, Norway; (F.R.); (I.W.); (N.M.); (J.-O.W.)
| | - Nabin Malla
- Molecular Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT—The Arctic University of Norway, NO-9037 Tromsø, Norway; (F.R.); (I.W.); (N.M.); (J.-O.W.)
| | - Ove Alexander Høgmoen Åstrand
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, NO-0316 Oslo, Norway; (O.A.H.Å.); (P.R.)
| | - Pål Rongved
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, NO-0316 Oslo, Norway; (O.A.H.Å.); (P.R.)
| | - Jan-Olof Winberg
- Molecular Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT—The Arctic University of Norway, NO-9037 Tromsø, Norway; (F.R.); (I.W.); (N.M.); (J.-O.W.)
| | - Ingebrigt Sylte
- Molecular Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT—The Arctic University of Norway, NO-9037 Tromsø, Norway; (F.R.); (I.W.); (N.M.); (J.-O.W.)
- Correspondence: ; Tel.: +47-7764-4705
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12
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Lim PN, Wang Z, Tong SY, Ho B, Wang W, Aizawa M, Yang Z, Thian ES. Silver, silicon co-substituted hydroxyapatite modulates bacteria-cell competition for enhanced osteogenic function. Biomed Mater 2021; 16. [PMID: 34375969 DOI: 10.1088/1748-605x/ac1c62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/10/2021] [Indexed: 11/12/2022]
Abstract
Combating bacteria while promoting tissue regeneration is an aim of highest priority for employing biomaterials in orthopedics that often embroiled with pre-operative contamination. Through simulating a surgical site infection environment and an infected implant site, we showcase the ability of a functionally modified hydroxyapatite, Ag,Si-HA that permits preferential adhesion of human bone marrow derived mesenchymal stem cells (BMSCs) over co-cultured bacterial pathogen,Pseudomonas aeruginosa, by displaying immediate suppression and killing of the bacteria present with minimum cytotoxicity for 28 d. And, at the same time, Ag,Si-HA stimulates BMSCs towards osteogenic differentiation despite being within the contaminated milieu. These findings provide well-defined requirements for incorporating antibacterial properties to biomaterials in managing pre-operative contamination. In addition, it highlights the dual positive attributes of Ag,Si-HA as an effective antibacterial biomaterial and at the same time, promotes bone tissue regeneration.
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Affiliation(s)
- Poon Nian Lim
- Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore
| | - Zuyong Wang
- College of Materials Science and Engineering, Hunan University, Changsha, People's Republic of China
| | - Shi Yun Tong
- Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore
| | - Bow Ho
- Department of Food Science & Technology, National University of Singapore, Singapore, Singapore
| | - Wilson Wang
- Department of Orthopaedic Surgery, National University of Singapore, Singapore, Singapore
| | - Mamoru Aizawa
- Department of Applied Chemistry, School of Science and Technology, Meiji University, Kawasaki, Japan
| | - Zhijie Yang
- Zhejiang Biocare Biotechnology Co. Ltd, Shaoxing, People's Republic of China
| | - Eng San Thian
- Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore
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13
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Rahman F, Nguyen TM, Adekoya OA, Campestre C, Tortorella P, Sylte I, Winberg JO. Inhibition of bacterial and human zinc-metalloproteases by bisphosphonate- and catechol-containing compounds. J Enzyme Inhib Med Chem 2021; 36:819-830. [PMID: 33757387 PMCID: PMC7993378 DOI: 10.1080/14756366.2021.1901088] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Compounds containg catechol or bisphosphonate were tested as inhibitors of the zinc metalloproteases, thermolysin (TLN), pseudolysin (PLN) and aureolysin (ALN) which are bacterial virulence factors, and the human matrix metalloproteases MMP-9 and -14. Inhibition of virulence is a putative strategy in the development of antibacterial drugs, but the inhibitors should not interfere with human enzymes. Docking indicated that the inhibitors bound MMP-9 and MMP-14 with the phenyl, biphenyl, chlorophenyl, nitrophenyl or methoxyphenyl ringsystem in the S1'-subpocket, while these ringsystems entered the S2'- or S1 -subpockets or a region involving amino acids in the S1'- and S2'-subpockets of the bacterial enzymes. An arginine conserved among the bacterial enzymes seemed to hinder entrance deeply into the S1'-subpocket. Only the bisphosphonate containing compound RC2 bound stronger to PLN and TLN than to MMP-9 and MMP-14. Docking indicated that the reason was that the conserved arginine (R203 in TLN and R198 in PLN) interacts with phosphate groups of RC2.
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Affiliation(s)
- Fatema Rahman
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Tra-Mi Nguyen
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Olayiwola A Adekoya
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Cristina Campestre
- Department of Pharmacy, University of "G. d'Annunzio" Chieti, Chieti, Italy
| | - Paolo Tortorella
- Department of Pharmacy, Science of Pharmacy, University "A. Moro" Bari, Bari, Italy
| | - Ingebrigt Sylte
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Jan-Olof Winberg
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
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14
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Abundant Monovalent Ions as Environmental Signposts for Pathogens during Host Colonization. Infect Immun 2021; 89:IAI.00641-20. [PMID: 33526568 DOI: 10.1128/iai.00641-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Host colonization by a pathogen requires proper sensing and response to local environmental cues, to ensure adaptation and continued survival within the host. The ionic milieu represents a critical potential source of environmental cues, and indeed, there has been extensive study of the interplay between host and pathogen in the context of metals such as iron, zinc, and manganese, vital ions that are actively sequestered by the host. The inherent non-uniformity of the ionic milieu also extends, however, to "abundant" ions such as chloride and potassium, whose concentrations vary greatly between tissue and cellular locations, and with the immune response. Despite this, the concept of abundant ions as environmental cues and key players in host-pathogen interactions is only just emerging. Focusing on chloride and potassium, this review brings together studies across multiple bacterial and parasitic species that have begun to define both how these abundant ions are exploited as cues during host infection, and how they can be actively manipulated by pathogens during host colonization. The close links between ion homeostasis and sensing/response to different ionic signals, and the importance of studying pathogen response to cues in combination, are also discussed, while considering the fundamental insight still to be uncovered from further studies in this nascent area of inquiry.
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15
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Javed M, Jentzsch B, Heinrich M, Ueltzhoeffer V, Peter S, Schoppmeier U, Angelov A, Schwarz S, Willmann M. Transcriptomic Basis of Serum Resistance and Virulence Related Traits in XDR P. aeruginosa Evolved Under Antibiotic Pressure in a Morbidostat Device. Front Microbiol 2021; 11:619542. [PMID: 33569046 PMCID: PMC7868568 DOI: 10.3389/fmicb.2020.619542] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/30/2020] [Indexed: 01/11/2023] Open
Abstract
Colistin is a last resort antibiotic against the critical status pathogen Pseudomonas aeruginosa. Virulence and related traits such as biofilm formation and serum resistance after exposure to sub-inhibitory levels of colistin have been underexplored. We cultivated P. aeruginosa in a semi-automated morbidostat device with colistin, metronidazole and a combination of the two antibiotics for 21 days, and completed RNA-Seq to uncover the transcriptional changes over time. Strains became resistant to colistin within this time period. Colistin-resistant strains show significantly increased biofilm formation: the cell density in biofilm increases under exposure to colistin, while the addition of metronidazole can remove this effect. After 7 days of colistin exposure, strains develop an ability to grow in serum, suggesting that colistin drives bacterial modifications conferring a protective effect from serum complement factors. Of note, strains exposed to colistin showed a decrease in virulence, when measured using the Galleria mellonella infection model. These phenotypic changes were characterized by a series of differential gene expression changes, particularly those related to LPS modifications, spermidine synthesis (via speH and speE) and the major stress response regulator rpoS. Our results suggest a clinically important bacterial evolution under sub-lethal antibiotic concentration leading to potential for significant changes in the clinical course of infection.
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Affiliation(s)
- Mumina Javed
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Benedikt Jentzsch
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Maximilian Heinrich
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Viola Ueltzhoeffer
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany
| | - Silke Peter
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Ulrich Schoppmeier
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany
| | - Angel Angelov
- NGS Competence Center Tübingen (NCCT), Tübingen, Germany
| | - Sandra Schwarz
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany
| | - Matthias Willmann
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Institute of Medical Microbiology and Hygiene, Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany.,Eurofins MVZ Medizinisches Labor Gelsenkirchen, Gelsenkirchen, Germany
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16
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A Al-Kafaween M, Mohd Hilmi AB, A Nagi Al-Jamal H, A Elsahoryi N, Jaffar N, Khairi Zahri M. Pseudomonas Aeruginosa and Streptococcus Pyogenes Exposed to Malaysian Trigona Honey In Vitro Demonstrated Downregulation of Virulence Factor. IRANIAN JOURNAL OF BIOTECHNOLOGY 2020; 18:e2542. [PMID: 34056021 PMCID: PMC8148639 DOI: 10.30498/ijb.2020.2542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Background Honey has been known as a traditional medicine for centuries with its antibacterial properties. It is considered one of the most enduring substances used in wound management. Objectives This study aimed to: (i) evaluate the effects of Malaysian Trigona honey on bacterial structure and (ii) assess the anti-virulence potential of this honey by examining their impacts on the expression of selected genes (involved in stress survival and biofilm formation) in a test organism. Materials and Methods Trigona honey's impacts on the bacterial structure (cell morphology) and the expression profiles of select Pseudomonas Aeruginosa and Streptococcus Pyogenes genes were examined using scanning electron microscopy (SEM) and real-time PCR (RT-qPCR) analysis, respectively. Results SEM showed that the decreased cell density deformed, disrupted, and damaged cells for both bacteria. RT-qPCR showed that the expression of fleN, fleQ, and fleR genes of P.aeruginosa were decreased, 4.26-fold, 3.80-fold and 2.66- fold respectively. In addition, scpA, ftsY, and emm13 of S.pyogenes were decreased, 2.87-fold, 3.24-fold, and 4.65-fold respectively. Conclusion Our results indicate that Trigona honey may be an effective inhibitor and virulence modulator of P. aeruginosa and S. pyogenes via multiple molecular targets. This deduction needs to be investigated in vivo.
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Affiliation(s)
| | - Abu Bakar Mohd Hilmi
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
| | | | - Nour A Elsahoryi
- Department of Nutrition /Faculty of Pharmacy and Medical Sciences/University of Petra/Amman/Jordan
| | - Norzawani Jaffar
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
| | - Mohd Khairi Zahri
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
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17
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Rodrigues YC, Furlaneto IP, Maciel AHP, Quaresma AJPG, de Matos ECO, Conceição ML, Vieira MCDS, Brabo GLDC, Sarges EDSNF, Lima LNGC, Lima KVB. High prevalence of atypical virulotype and genetically diverse background among Pseudomonas aeruginosa isolates from a referral hospital in the Brazilian Amazon. PLoS One 2020; 15:e0238741. [PMID: 32911510 PMCID: PMC7482967 DOI: 10.1371/journal.pone.0238741] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 08/21/2020] [Indexed: 12/23/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing different types of infections, particularly in intensive care unit patients. Characteristics that favor its persistence artificial environments are related to its high adaptability, wide arsenal of virulence factors and resistance to several antimicrobial classes. Among the several virulence determinants, T3SS stands as the most important due to the clinical impact of exoS and exoU genes in patient’s outcome. The molecular characterization of P. aeruginosa isolates helps in the comprehension of transmission dynamics and enhance knowledge of virulence and resistance roles in infection process. In the present study, we investigated virulence and resistance properties and the genetic background of P. aeruginosa isolated from ICUs patients at a referral hospital in Brazilian Amazon. A total of 54 P. aeruginosa isolates were characterized by detecting 19 virulence-related genes, antimicrobial susceptibility testing, molecular detection of β-lactamase-encoding genes and genotyping by MLST and rep-PCR. Our findings showed high prevalence of virulence-related markers, where 53.7% of the isolates presented at least 17 genes among the 19 investigated (P = 0.01). The rare exoS+/exoU+ cytotoxic virulotype was detected in 55.6% of isolates. Antimicrobial susceptibility testing revealed percentages of antibiotic resistance above 50% to carbapenems, cephalosporins and fluoroquinolones associated to MDR/XDR isolates. Isolates harboring both blaSPM-1 and blaOXA genes were also detected. Genotyping methods demonstrated a wide genetic diversity of strains spread among the different intensive care units, circulation of international MDR/XDR high-risk clones (ST111, ST235, ST244 and ST277) and emergence of seven novel MLST lineages. Finally, our findings highlight the circulation of strains with high virulence potential and resistance to antimicrobials and may be useful on comprehension of pathogenicity process, treatment guidance and establishment of strategies to control the spread of epidemic P. aeruginosa strains.
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Affiliation(s)
- Yan Corrêa Rodrigues
- Programa de Pós-graduação em Biologia Parasitária na Amazônia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
- * E-mail: (YCR); (KVBL)
| | - Ismari Perini Furlaneto
- Programa de Pós-graduação em Educação em Saúde, Centro Universitário do Pará (CESUPA), Belém, Pará Brazil
| | - Arthur Henrique Pinto Maciel
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | - Ana Judith Pires Garcia Quaresma
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | - Eliseth Costa Oliveira de Matos
- Departamento de Patologia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
| | - Marília Lima Conceição
- Programa de Pós-graduação em Biologia Parasitária na Amazônia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
| | - Marcelo Cleyton da Silva Vieira
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | - Giulia Leão da Cunha Brabo
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | | | - Luana Nepomuceno Godim Costa Lima
- Programa de Pós-graduação em Biologia Parasitária na Amazônia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
| | - Karla Valéria Batista Lima
- Programa de Pós-graduação em Biologia Parasitária na Amazônia, Centro de Ciências Biológicas e da Saúde, Universidade do Estado do Pará (UEPA), Belém, Pará, Brazil
- Laboratório de Biologia Molecular, Seção de Bacteriologia e Micologia, Instituto Evandro Chagas (IEC), Ministério da Saúde, Ananindeua, Pará, Brazil
- * E-mail: (YCR); (KVBL)
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18
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Stanton BA, Hampton TH, Ashare A. SARS-CoV-2 (COVID-19) and cystic fibrosis. Am J Physiol Lung Cell Mol Physiol 2020; 319:L408-L415. [PMID: 32668165 PMCID: PMC7518058 DOI: 10.1152/ajplung.00225.2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/06/2020] [Accepted: 07/06/2020] [Indexed: 12/16/2022] Open
Abstract
Cystic fibrosis (CF) is a genetic disease caused by mutations in the CFTR gene. Although viral respiratory tract infections are, in general, more severe in patients with CF compared with the general population, a small number of studies indicate that SARS-CoV-2 does not cause a worse infection in CF. This is surprising since comorbidities including preexisting lung disease have been reported to be associated with worse outcomes in SARS-CoV-2 infections. Several recent studies provide insight into why SARS-CoV-2 may not produce more severe outcomes in CF. First, ACE and ACE2, genes that play key roles in SARS-CoV-2 infection, have some variants that are predicted to reduce the severity of SARS-CoV-2 infection. Second, mRNA for ACE2 is elevated and mRNA for TMPRSS2, a serine protease, is decreased in CF airway epithelial cells. Increased ACE2 is predicted to enhance SARS-CoV-2 binding to cells but would increase conversion of angiotensin II, which is proinflammatory, to angiotensin-1-7, which is anti-inflammatory. Thus, increased ACE2 would reduce inflammation and lung damage due to SARS-CoV-2. Moreover, decreased TMPRSS2 would reduce SARS-CoV-2 entry into airway epithelial cells. Second, many CF patients are treated with azithromycin, which suppresses viral infection and lung inflammation and inhibits the activity of furin, a serine protease. Finally, the CF lung contains high levels of serine protease inhibitors including ecotin and SERPINB1, which are predicted to reduce the ability of TMPRSS2 to facilitate SARS-CoV-2 entry into airway epithelial cells. Thus, a variety of factors may mitigate the severity of SARS-CoV-2 in CF.
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Affiliation(s)
- Bruce A Stanton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Thomas H Hampton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Alix Ashare
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
- Section of Pulmonology, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
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19
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Shi X, Zhao F, Sun H, Yu X, Zhang C, Liu W, Pan Q, Ren H. Characterization and Complete Genome Analysis of Pseudomonas aeruginosa Bacteriophage vB_PaeP_LP14 Belonging to Genus Litunavirus. Curr Microbiol 2020; 77:2465-2474. [PMID: 32367280 DOI: 10.1007/s00284-020-02011-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/24/2020] [Indexed: 12/17/2022]
Abstract
A lytic Pseudomonas aeruginosa phage vB_PaeP_LP14 belonging to the family Podoviridae was isolated from infected mink. The microbiological characterization revealed that LP14 was stable at 40 to 50 °C and stable over a broad range of pH (5 to 12). The latent period was 5 min, and the burst size was 785 pfu/infected cell. The whole-genome sequencing showed that LP14 was a dsDNA virus and has a genome of 73,080 bp. The genome contained 93 predicted open reading frames (ORFs), 17 of which have known functions including DNA replication and modification, transcriptional regulation, structural and packaging proteins, and host cell lysis. No tRNA genes were identified. BLASTn analysis revealed that phage LP14 had a high-sequence identity (96%) with P. aeruginosa phage YH6. Both morphological characterization and genome annotation indicate that phage LP14 is a memberof the family Podoviridae genus Litunavirus. The study of phage LP14 will provide basic information for further research on treatment of P. aeruginosa infections.
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Affiliation(s)
- Xiaojie Shi
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Feiyang Zhao
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Huzhi Sun
- Qingdao Phagepharm Bio-tech Co, Ltd, Qingdao, Shandong, China
| | - Xiaoyan Yu
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Can Zhang
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Wenhua Liu
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Qiang Pan
- Qingdao Phagepharm Bio-tech Co, Ltd, Qingdao, Shandong, China
| | - Huiying Ren
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong, China.
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20
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Pseudomonas haemolytica sp. nov., isolated from raw milk and skimmed milk concentrate. Int J Syst Evol Microbiol 2020; 70:2339-2347. [DOI: 10.1099/ijsem.0.004043] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two strains, WS 5063T and WS 5067, isolated from raw cow’s milk and skimmed milk concentrate, could be affiliated as members of the same, hitherto unknown,
Pseudomonas
species by 16S rRNA and rpoD gene sequences. Multilocus sequence and average nucleotide identity (ANIm) analyses based on draft genome sequences confirmed the discovery of a novel
Pseudomonas
species. It was most closely related to
Pseudomonas synxantha
DSM 18928T with an ANIm of 91.4 %. The DNA G+C content of WS 5063T was 60.0 mol %. Phenotypic characterizations showed that the isolates are rod-shaped, motile, catalase- and oxidase-positive, and aerobic. Growth occurred at 4–34 °C and at pH values of pH 5.5–8.0. Both strains showed strong β-haemolysis on blood agar. The major cellular polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The dominant quinone was Q-9 (90 %), but noticeable amounts of Q-8 (9 %) and traces of Q-7 were also detected. Fatty acid profiles were typical for
Pseudomonas
species and exhibited C16 : 0 as a major component. Based on these results, we conclude that both strains belong to a novel species, for which the name Pseudomonas haemolytica sp. nov. is proposed. The type strain is WS 5063T (=DSM 108987T=LMG 31232T) and an additional strain is WS 5067 (=DSM 108988=LMG 31233).
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21
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Pseudomonas aeruginosa Toxin ExoU as a Therapeutic Target in the Treatment of Bacterial Infections. Microorganisms 2019; 7:microorganisms7120707. [PMID: 31888268 PMCID: PMC6955817 DOI: 10.3390/microorganisms7120707] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/10/2019] [Accepted: 12/14/2019] [Indexed: 12/20/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa employs the type III secretion system (T3SS) and four effector proteins, ExoS, ExoT, ExoU, and ExoY, to disrupt cellular physiology and subvert the host’s innate immune response. Of the effector proteins delivered by the T3SS, ExoU is the most toxic. In P. aeruginosa infections, where the ExoU gene is expressed, disease severity is increased with poorer prognoses. This is considered to be due to the rapid and irreversible damage exerted by the phospholipase activity of ExoU, which cannot be halted before conventional antibiotics can successfully eliminate the pathogen. This review will discuss what is currently known about ExoU and explore its potential as a therapeutic target, highlighting some of the small molecule ExoU inhibitors that have been discovered from screening approaches.
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22
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Ahator SD, Zhang L. Small Is Mighty—Chemical Communication Systems in Pseudomonas aeruginosa. Annu Rev Microbiol 2019; 73:559-578. [DOI: 10.1146/annurev-micro-020518-120044] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes a variety of acute and chronic infections. Usually a commensal on the host body, P. aeruginosa is capable of transforming into a virulent pathogen upon sensing favorable changes in the host immune system or stress cues. P. aeruginosa infections are hard to eradicate, because this pathogen has developed strong resistance to most conventional antibiotics; in addition, in chronic infections it commonly forms a biofilm matrix, which provides bacterial cells a protected environment to withstand various stresses including antibiotics. Given its importance as a human pathogen and its notorious antimicrobial tolerance, P. aeruginosa has been the subject of intensive investigations internationally. Research progress over the last two decades has unveiled a range of chemical communication systems in this pathogen. These diversified chemical communication systems endow P. aeruginosa a superb ability and remarkable flexibility to coordinate and modulate accordingly the transcriptional expression of various sets of genes associated with virulence and other physiologic activities in response to environmental changes. A fair understanding of the chemical signaling mechanisms with which P. aeruginosa governs virulence gene expression may hold the key to developing alternative therapeutic interventions that control and prevent bacterial infections.
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Affiliation(s)
- Stephen Dela Ahator
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou 510642, China
| | - LianHui Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou 510642, China
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23
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Koeppen K, Barnaby R, Jackson AA, Gerber SA, Hogan DA, Stanton BA. Tobramycin reduces key virulence determinants in the proteome of Pseudomonas aeruginosa outer membrane vesicles. PLoS One 2019; 14:e0211290. [PMID: 30682135 PMCID: PMC6347270 DOI: 10.1371/journal.pone.0211290] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/10/2019] [Indexed: 12/20/2022] Open
Abstract
Tobramycin is commonly used to treat Pseudomonas aeruginosa lung infections in patients with Cystic Fibrosis (CF). Tobramycin treatment leads to increased lung function and fewer clinical exacerbations in CF patients, and modestly reduces the density of P. aeruginosa in the lungs. P. aeruginosa resides primarily in the mucus overlying lung epithelial cells and secretes outer membrane vesicles (OMVs) that diffuse through the mucus and fuse with airway epithelial cells, thus delivering virulence factors into the cytoplasm that modify the innate immune response. The goal of this study was to test the hypothesis that Tobramycin reduces the abundance of virulence factors in OMVs secreted by P. aeruginosa. Characterization of the proteome of OMVs isolated from control or Tobramycin-exposed P. aeruginosa strain PAO1 revealed that Tobramycin reduced several OMV-associated virulence determinants, including AprA, an alkaline protease that enhances P. aeruginosa survival in the lung, and is predicted to contribute to the inhibitory effect of P. aeruginosa on Phe508del-CFTR Cl- secretion by primary human bronchial epithelial cells. Deletion of the gene encoding AprA reduced the inhibitory effect of P. aeruginosa on Phe508del-CFTR Cl- secretion. Moreover, as predicted by our proteomic analysis, OMVs isolated from Tobramycin treated P. aeruginosa had a diminished inhibitory effect on Phe508del-CFTR Cl- secretion compared to OMVs isolated from control P. aeruginosa. Taken together, our proteomic analysis of OMVs and biological validation suggest that Tobramycin may improve lung function in CF patients infected with P. aeruginosa by reducing several key virulence factors in OMVs that reduce CFTR Cl- secretion, which is essential for bacterial clearance from the lungs.
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Affiliation(s)
- Katja Koeppen
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- * E-mail:
| | - Roxanna Barnaby
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Angelyca A. Jackson
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Scott A. Gerber
- Department of Molecular and Systems Biology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Deborah A. Hogan
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Bruce A. Stanton
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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24
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Updates on the pathogenicity status of Pseudomonas aeruginosa. Drug Discov Today 2019; 24:350-359. [DOI: 10.1016/j.drudis.2018.07.003] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/03/2018] [Accepted: 07/16/2018] [Indexed: 01/06/2023]
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25
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Sylte I, Dawadi R, Malla N, von Hofsten S, Nguyen TM, Solli AI, Berg E, Adekoya OA, Svineng G, Winberg JO. The selectivity of galardin and an azasugar-based hydroxamate compound for human matrix metalloproteases and bacterial metalloproteases. PLoS One 2018; 13:e0200237. [PMID: 30075004 PMCID: PMC6075749 DOI: 10.1371/journal.pone.0200237] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 06/22/2018] [Indexed: 02/07/2023] Open
Abstract
Inhibitors targeting bacterial enzymes should not interfere with enzymes of the host, and knowledge about structural determinants for selectivity is important for designing inhibitors with a therapeutic potential. We have determined the binding strengths of two hydroxamate compounds, galardin and compound 1b for the bacterial zinc metalloproteases, thermolysin, pseudolysin and auerolysin, known to be bacterial virulence factors, and the two human zinc metalloproteases MMP-9 and MMP-14. The active sites of the bacterial and human enzymes have huge similarities. In addition, we also studied the enzyme-inhibitor interactions by molecular modelling. The obtained Ki values of galardin for MMP-9 and MMP-14 and compound 1b for MMP-9 are approximately ten times lower than previously reported. Compound 1b binds stronger than galardin to both MMP-9 and MMP-14, and docking studies indicated that the diphenyl ether moiety of compound 1b obtains more favourable interactions within the S´1-subpocket than the 4-methylpentanoyl moiety of galardin. Both compounds bind stronger to MMP-9 than to MMP-14, which appears to be due to a larger S´1-subpocket in the former enzyme. Galardin, but not 1b, inhibits the bacterial enzymes, but the galardin Ki values were much larger than for the MMPs. The docking indicates that the S´1-subpockets of the bacterial proteases are too small to accommodate the diphenyl ether moiety of 1b, while the 4-methylpentanoyl moiety of galardin enters the pocket. The present study indicates that the size and shape of the ligand structural moiety entering the S´1-subpocket is an important determinant for selectivity between the studied MMPs and bacterial MPs.
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Affiliation(s)
- Ingebrigt Sylte
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Rangita Dawadi
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Nabin Malla
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Susannah von Hofsten
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Tra-Mi Nguyen
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Ann Iren Solli
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Eli Berg
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Olayiwola A. Adekoya
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Gunbjørg Svineng
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Jan-Olof Winberg
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
- * E-mail:
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26
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Kushwaha M, Jain SK, Sharma N, Abrol V, Jaglan S, Vishwakarma RA. Establishment of LCMS Based Platform for Discovery of Quorum Sensing Inhibitors: Signal Detection in Pseudomonas aeruginosa PAO1. ACS Chem Biol 2018; 13:657-665. [PMID: 29303546 DOI: 10.1021/acschembio.7b00875] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Targeting the main three networking systems, viz. Las, RhI, and PQS, via natural quenchers is a new ray of hope for combating the persistent behavior of Pseudomonas aeruginosa. In the bacterial chemical vocabulary pyocyanin, N-AHLs and rhamnolipids are the main keywords, which are responsible for the social and nomadic behavior of P. aeruginosa. In the present work, LC-MS based real-time qualitative and quantitative analysis of pyocyanin, green phenazine, N-AHLs, and rhamnolipids were performed on P. aeruginosa PAO1. The quantitative analysis indicates that the production of pyocyanin and NHSLs increases with time while the production of rhamnolipids discontinued after 16 h. This indicates the emergence of persisters in the medium instead of planktonic cells. Rhamnolipids acting as a surfactant enhances the motility of the bacterial cells, whereas the pyocyanin is responsible for the biofilm formation. In a microtiter plate based assay, an effect of capsaicin and 6-gingerol was recorded. In the presence of capsaicin and 6-gingerol, a substantial decrease in the production of rhamnolipids, phenazine, quinolone, and N-AHLs was observed. Most interestingly, the 6-gingerol treatment led to a drastic decrease of rhamnolipids, phenazine, quinolone, and N-AHLs versus capsaicin. These studies demonstrate the effectiveness of the capsaicin and 6-gingerol on Las, PQS, and Rhl circuits in a bacterium in order to understand the persistent and social behavior. Here, we are reporting LC-MS/MS based qualitative and quantitative analysis of QS molecules by taking a low volume of culture (up to 200 μL). This method can be used as a platform to screen the new antivirulence agents for fighting the resistant behavior of P. aeruginosa during biofilm formation.
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Affiliation(s)
- Manoj Kushwaha
- Microbial Biotechnology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu-180001, India
- Department of Biotechnology, Guru Nanak Dev University, Amritsar-143001, Punjab, India
| | - Shreyans K. Jain
- Natural Product Chemistry Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu-180001, India
| | - Nisha Sharma
- Microbial Biotechnology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu-180001, India
- Academy of Scientific and Innovative Research, Jammu Campus, Jammu-180001, India
| | - Vidushi Abrol
- Microbial Biotechnology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu-180001, India
| | - Sundeep Jaglan
- Microbial Biotechnology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu-180001, India
- Academy of Scientific and Innovative Research, Jammu Campus, Jammu-180001, India
| | - Ram A. Vishwakarma
- Medicinal Chemistry Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu-180001, India
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de Benito A, Ibáñez C, Moncho W, Martínez D, Vettorazzi A, de Cerain AL. Database on the taxonomical characterisation and potential toxigenic capacities of microorganisms used for the industrial production of food enzymes and feed additives, which do not have a recommendation for Qualified Presumption of Safety. EFSA SUPPORTING PUBLICATIONS 2017. [PMCID: PMC7163622 DOI: 10.2903/sp.efsa.2017.en-1274] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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28
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Multiple Ligand-Bound States of a Phosphohexomutase Revealed by Principal Component Analysis of NMR Peak Shifts. Sci Rep 2017; 7:5343. [PMID: 28706231 PMCID: PMC5509744 DOI: 10.1038/s41598-017-05557-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 05/31/2017] [Indexed: 11/08/2022] Open
Abstract
Enzymes sample multiple conformations during their catalytic cycles. Chemical shifts from Nuclear Magnetic Resonance (NMR) are hypersensitive to conformational changes and ensembles in solution. Phosphomannomutase/phosphoglucomutase (PMM/PGM) is a ubiquitous four-domain enzyme that catalyzes phosphoryl transfer across phosphohexose substrates. We compared states the enzyme visits during its catalytic cycle. Collective responses of Pseudomonas PMM/PGM to phosphosugar substrates and inhibitor were assessed using NMR-detected titrations. Affinities were estimated from binding isotherms obtained by principal component analysis (PCA). Relationships among phosphosugar-enzyme associations emerge from PCA comparisons of the titrations. COordiNated Chemical Shifts bEhavior (CONCISE) analysis provides novel discrimination of three ligand-bound states of PMM/PGM harboring a mutation that suppresses activity. Enzyme phosphorylation and phosphosugar binding appear to drive the open dephosphorylated enzyme to the free phosphorylated state, and on toward ligand-closed states. Domain 4 appears central to collective responses to substrate and inhibitor binding. Hydrogen exchange reveals that binding of a substrate analogue enhances folding stability of the domains to a uniform level, establishing a globally unified structure. CONCISE and PCA of NMR spectra have discovered novel states of a well-studied enzyme and appear ready to discriminate other enzyme and ligand binding states.
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29
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Geisinger E, Isberg RR. Interplay Between Antibiotic Resistance and Virulence During Disease Promoted by Multidrug-Resistant Bacteria. J Infect Dis 2017; 215:S9-S17. [PMID: 28375515 DOI: 10.1093/infdis/jiw402] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Diseases caused by antibiotic-resistant bacteria in hospitals are the outcome of complex relationships between several dynamic factors, including bacterial pathogenicity, the fitness costs of resistance in the human host, and selective forces resulting from interventions such as antibiotic therapy. The emergence and fate of mutations that drive antibiotic resistance are governed by these interactions. In this review, we will examine how different forms of antibiotic resistance modulate bacterial fitness and virulence potential, thus influencing the ability of pathogens to evolve in the context of nosocomial infections. We will focus on 3 important multidrug-resistant pathogens that are notoriously problematic in hospitals: Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. An understanding of how antibiotic resistance mutations shape the pathobiology of multidrug-resistant infections has the potential to drive novel strategies that can control the development and spread of drug resistance.
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Affiliation(s)
- Edward Geisinger
- Howard Hughes Medical Institute, and.,Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts
| | - Ralph R Isberg
- Howard Hughes Medical Institute, and.,Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts
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30
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Bartell JA, Blazier AS, Yen P, Thøgersen JC, Jelsbak L, Goldberg JB, Papin JA. Reconstruction of the metabolic network of Pseudomonas aeruginosa to interrogate virulence factor synthesis. Nat Commun 2017; 8:14631. [PMID: 28266498 PMCID: PMC5344303 DOI: 10.1038/ncomms14631] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 01/18/2017] [Indexed: 01/13/2023] Open
Abstract
Virulence-linked pathways in opportunistic pathogens are putative therapeutic targets that may be associated with less potential for resistance than targets in growth-essential pathways. However, efficacy of virulence-linked targets may be affected by the contribution of virulence-related genes to metabolism. We evaluate the complex interrelationships between growth and virulence-linked pathways using a genome-scale metabolic network reconstruction of Pseudomonas aeruginosa strain PA14 and an updated, expanded reconstruction of P. aeruginosa strain PAO1. The PA14 reconstruction accounts for the activity of 112 virulence-linked genes and virulence factor synthesis pathways that produce 17 unique compounds. We integrate eight published genome-scale mutant screens to validate gene essentiality predictions in rich media, contextualize intra-screen discrepancies and evaluate virulence-linked gene distribution across essentiality datasets. Computational screening further elucidates interconnectivity between inhibition of virulence factor synthesis and growth. Successful validation of selected gene perturbations using PA14 transposon mutants demonstrates the utility of model-driven screening of therapeutic targets.
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Affiliation(s)
- Jennifer A. Bartell
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2970 Hørsholm, Denmark
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Anna S. Blazier
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Phillip Yen
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Juliane C. Thøgersen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Lars Jelsbak
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Joanna B. Goldberg
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis and Sleep, Children's Healthcare of Atlanta, Atlanta, Georgia 30322, USA
- Emory+Children's Center for Cystic Fibrosis Research, Emory University and Children's Healthcare of Atlanta, Atlanta, Georgia 30322, USA
| | - Jason A. Papin
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA
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31
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Bahl CD, St. Laurent JD, Karthikeyan RSG, Priya JL, Prajna L, Zegans ME, Madden DR. The cif Virulence Factor Gene Is Present in Isolates From Patients With Pseudomonas aeruginosa Keratitis. Cornea 2017; 36:358-362. [PMID: 28079684 PMCID: PMC5290206 DOI: 10.1097/ico.0000000000001132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE To determine whether the cif gene is present in pathogenic Pseudomonas aeruginosa isolates from patients with bacterial keratitis at Aravind Eye Hospital, a referral eye care center in southern India, and from corresponding environmental isolates. METHODS Polymerase chain reaction amplification was performed on strains of P. aeruginosa isolated from ocular infections and environmental soil samples were collected from the area surrounding Aravind Eye Hospital. DNA sequencing of 16S ribosomal DNA amplicons was performed to verify strain identity. RESULTS We determined that 45 of 48 patient isolates carry a genomic copy of cif. Analysis of a catalog of environmental strains previously isolated from the surrounding area revealed that only 4 of 10 P. aeruginosa strains and 1 of 14 strains of related species carry the cif gene. CONCLUSIONS This is the first study to show that P. aeruginosa strains with ocular pathogenicity carry the cif gene and that the presence of this gene may be enriched over its prevalence in the environment. Taken together, these results suggest a potential role for Cif in acute bacterial keratitis.
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Affiliation(s)
- Christopher D. Bahl
- Department of Biochemistry & Cell Biology, Geisel School of
Medicine at Dartmouth, Hanover, NH, USA
| | - Jessica D. St. Laurent
- Department of Biochemistry & Cell Biology, Geisel School of
Medicine at Dartmouth, Hanover, NH, USA
| | - R. Siva Ganesa Karthikeyan
- Department of Ocular Microbiology, Dr G. Venkatasamy Eye Research
Institute, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - J. Lakshmi Priya
- Department of Ocular Microbiology, Dr G. Venkatasamy Eye Research
Institute, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - Lalitha Prajna
- Department of Ocular Microbiology, Dr G. Venkatasamy Eye Research
Institute, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
| | - Michael E. Zegans
- Department of Surgery (Ophthalmology), Geisel School of Medicine at
Dartmouth, Hanover, NH, USA
- Department of Microbiology & Immunology, Geisel School of
Medicine at Dartmouth, Hanover, NH, USA
| | - Dean R. Madden
- Department of Biochemistry & Cell Biology, Geisel School of
Medicine at Dartmouth, Hanover, NH, USA
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32
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Stanton BA. Effects of Pseudomonas aeruginosa on CFTR chloride secretion and the host immune response. Am J Physiol Cell Physiol 2017; 312:C357-C366. [PMID: 28122735 DOI: 10.1152/ajpcell.00373.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 01/20/2017] [Accepted: 01/21/2017] [Indexed: 12/18/2022]
Abstract
In the healthy lung the opportunistic pathogen, Pseudomonas aeruginosa, is rapidly eliminated by mucociliary clearance, a process that is dependent on the activity of the CFTR anion channel that, in concert with a number of other transport proteins, regulates the volume and composition of the periciliary surface liquid. This fluid layer is essential to enable cilia to clear pathogens from the lungs. However, in cystic fibrosis (CF), mutations in the CFTR gene reduce Cl- and [Formula: see text] secretion, thereby decreasing periciliary surface liquid volume and mucociliary clearance of bacteria. In CF this leads to persistent infection with the opportunistic pathogen, P. aeruginosa, which is the cause of reduced lung function and death in ~95% of CF patients. Others and we have conducted studies to elucidate the effects of P. aeruginosa on wild-type and Phe508del-CFTR Cl- secretion as well as on the host immune response. These studies have demonstrated that Cif (CFTR inhibitory factor), a virulence factor secreted by P. aeruginosa, is associated with reduced lung function in CF and induces the ubiquitination and degradation of wt-CFTR as well as TAP1, which plays a key role in viral and bacterial antigen presentation. Cif also enhances the degradation of Phe508del-CFTR that has been rescued by ORKAMBI, a drug approved for CF patients homozygous for the Phe508del-CFTR mutation, thereby reducing drug efficacy. This review is based on the Hans Ussing Distinguished Lecture at the 2016 Experimental Biology Meeting given by the author.
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Affiliation(s)
- Bruce A Stanton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
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33
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Kaiser SJ, Mutters NT, DeRosa A, Ewers C, Frank U, Günther F. Determinants for persistence of Pseudomonas aeruginosa in hospitals: interplay between resistance, virulence and biofilm formation. Eur J Clin Microbiol Infect Dis 2016; 36:243-253. [PMID: 27734161 DOI: 10.1007/s10096-016-2792-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 09/14/2016] [Indexed: 12/27/2022]
Abstract
Pseudomonas aeruginosa (Pa) is one of the major bacterial pathogens causing nosocomial infections. During the past few decades, multidrug-resistant (MDR) and extensively drug-resistant (XDR) lineages of Pa have emerged in hospital settings with increasing numbers. However, it remains unclear which determinants of Pa facilitated this spread. A total of 211 clinical XDR and 38 susceptible clinical Pa isolates (nonXDR), as well as 47 environmental isolates (EI), were collected at the Heidelberg University Hospital. We used RAPD PCR to identify genetic clusters. Carriage of carbapenamases (CPM) and virulence genes were analyzed by PCR, biofilm formation capacity was assessed, in vitro fitness was evaluated using competitive growth assays, and interaction with the host's immune system was analyzed using serum killing and neutrophil killing assays. XDR isolates showed significantly elevated biofilm formation (p < 0.05) and higher competitive fitness compared to nonXDR and EI isolates. Thirty percent (62/205) of the XDR isolates carried a CPM. Similarities in distribution of virulence factors, as well as biofilm formation properties, between CPM+ Pa isolates and EI and between CPM- and nonXDR isolates were detected. Molecular typing revealed two distinct genetic clusters within the XDR population, which were characterized by even higher biofilm formation. In contrast, XDR isolates were more susceptible to the immune response than nonXDR isolates. Our study provides evidence that the ability to form biofilms is an outstanding determinant for persistence and endemic spread of Pa in the hospital setting.
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Affiliation(s)
- S J Kaiser
- Department of Infectious Diseases, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - N T Mutters
- Department of Infectious Diseases, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - A DeRosa
- Department of Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - C Ewers
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, Giessen, Germany
| | - U Frank
- Department of Infectious Diseases, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - F Günther
- Department of Infectious Diseases, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
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Maxson T, Mitchell DA. Targeted Treatment for Bacterial Infections: Prospects for Pathogen-Specific Antibiotics Coupled with Rapid Diagnostics. Tetrahedron 2016; 72:3609-3624. [PMID: 27429480 PMCID: PMC4941824 DOI: 10.1016/j.tet.2015.09.069] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Antibiotics are a cornerstone of modern medicine and have significantly reduced the burden of infectious diseases. However, commonly used broad-spectrum antibiotics can cause major collateral damage to the human microbiome, causing complications ranging from antibiotic-associated colitis to the rapid spread of resistance. Employing narrower spectrum antibiotics targeting specific pathogens may alleviate this predicament as well as provide additional tools to expand an antibiotic repertoire threatened by the inevitability of resistance. Improvements in clinical diagnosis will be required to effectively utilize pathogen-specific antibiotics and new molecular diagnostics are poised to fulfill this need. Here we review recent trends and the future prospects of deploying narrower spectrum antibiotics coupled with rapid diagnostics. Further, we discuss the theoretical advantages and limitations of this emerging approach to controlling bacterial infectious diseases.
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Affiliation(s)
- Tucker Maxson
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Douglas A. Mitchell
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Carle R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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35
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Kitamura S, Hvorecny KL, Niu J, Hammock BD, Madden DR, Morisseau C. Rational Design of Potent and Selective Inhibitors of an Epoxide Hydrolase Virulence Factor from Pseudomonas aeruginosa. J Med Chem 2016; 59:4790-9. [PMID: 27120257 DOI: 10.1021/acs.jmedchem.6b00173] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The virulence factor cystic fibrosis transmembrane conductance regulator (CFTR) inhibitory factor (Cif) is secreted by Pseudomonas aeruginosa and is the founding member of a distinct class of epoxide hydrolases (EHs) that triggers the catalysis-dependent degradation of the CFTR. We describe here the development of a series of potent and selective Cif inhibitors by structure-based drug design. Initial screening revealed 1a (KB2115), a thyroid hormone analog, as a lead compound with low micromolar potency. Structural requirements for potency were systematically probed, and interactions between Cif and 1a were characterized by X-ray crystallography. On the basis of these data, new compounds were designed to yield additional hydrogen bonding with residues of the Cif active site. From this effort, three compounds were identified that are 10-fold more potent toward Cif than our first-generation inhibitors and have no detectable thyroid hormone-like activity. These inhibitors will be useful tools to study the pathological role of Cif and have the potential for clinical application.
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Affiliation(s)
- Seiya Kitamura
- Department of Entomology and Nematology, and UC Davis Comprehensive Cancer Center, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
| | - Kelli L Hvorecny
- Department of Biochemistry, Geisel School of Medicine at Dartmouth , 7200 Vail Building, Hanover, New Hampshire 03755, United States
| | - Jun Niu
- Department of Entomology and Nematology, and UC Davis Comprehensive Cancer Center, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
| | - Bruce D Hammock
- Department of Entomology and Nematology, and UC Davis Comprehensive Cancer Center, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
| | - Dean R Madden
- Department of Biochemistry, Geisel School of Medicine at Dartmouth , 7200 Vail Building, Hanover, New Hampshire 03755, United States
| | - Christophe Morisseau
- Department of Entomology and Nematology, and UC Davis Comprehensive Cancer Center, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
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36
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Kasper SH, Bonocora RP, Wade JT, Musah RA, Cady NC. Chemical Inhibition of Kynureninase Reduces Pseudomonas aeruginosa Quorum Sensing and Virulence Factor Expression. ACS Chem Biol 2016; 11:1106-17. [PMID: 26785289 DOI: 10.1021/acschembio.5b01082] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa utilizes multiple quorum sensing (QS) pathways to coordinate an arsenal of virulence factors. We previously identified several cysteine-based compounds inspired by natural products from the plant Petiveria alliacea which are capable of antagonizing multiple QS circuits as well as reducing P. aeruginosa biofilm formation. To understand the global effects of such compounds on virulence factor production and elucidate their mechanism of action, RNA-seq transcriptomic analysis was performed on P. aeruginosa PAO1 exposed to S-phenyl-l-cysteine sulfoxide, the most potent inhibitor from the prior study. Exposure to this inhibitor down-regulated expression of several QS-regulated virulence operons (e.g., phenazine biosynthesis, type VI secretion systems). Interestingly, many genes that were differentially regulated pertain to the related metabolic pathways that yield precursors of pyochelin, tricarboxylic acid cycle intermediates, phenazines, and Pseudomonas quinolone signal (PQS). Activation of the MexT-regulon was also indicated, including the multidrug efflux pump encoded by mexEF-oprN, which has previously been shown to inhibit QS and pathogenicity. Deeper investigation of the metabolites involved in these systems revealed that S-phenyl-l-cysteine sulfoxide has structural similarity to kynurenine, a precursor of anthranilate, which is critical for P. aeruginosa virulence. By supplementing exogenous anthranilate, the QS-inhibitory effect was reversed. Finally, it was shown that S-phenyl-l-cysteine sulfoxide competitively inhibits P. aeruginosa kynureninase (KynU) activity in vitro and reduces PQS production in vivo. The kynurenine pathway has been implicated in P. aeruginosa QS and virulence factor expression; however, this is the first study to show that targeted inhibition of KynU affects P. aeruginosa gene expression and QS, suggesting a potential antivirulence strategy.
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Affiliation(s)
- Stephen H. Kasper
- Colleges
of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York, United States
| | - Richard P. Bonocora
- Wadsworth
Center, New York State Department of Health, Albany, New York, United States
| | - Joseph T. Wade
- Wadsworth
Center, New York State Department of Health, Albany, New York, United States
- Department
of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, United States
| | - Rabi Ann Musah
- Department
of Chemistry, University at Albany, SUNY, Albany, New York, United States
| | - Nathaniel C. Cady
- Colleges
of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York, United States
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Reuter K, Steinbach A, Helms V. Interfering with Bacterial Quorum Sensing. PERSPECTIVES IN MEDICINAL CHEMISTRY 2016; 8:1-15. [PMID: 26819549 PMCID: PMC4718088 DOI: 10.4137/pmc.s13209] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 01/22/2023]
Abstract
Quorum sensing (QS) describes the exchange of chemical signals in bacterial populations to adjust the bacterial phenotypes according to the density of bacterial cells. This serves to express phenotypes that are advantageous for the group and ensure bacterial survival. To do so, bacterial cells synthesize autoinducer (AI) molecules, release them to the environment, and take them up. Thereby, the AI concentration reflects the cell density. When the AI concentration exceeds a critical threshold in the cells, the AI may activate the expression of virulence-associated genes or of luminescent proteins. It has been argued that targeting the QS system puts less selective pressure on these pathogens and should avoid the development of resistant bacteria. Therefore, the molecular components of QS systems have been suggested as promising targets for developing new anti-infective compounds. Here, we review the QS systems of selected gram-negative and gram-positive bacteria, namely, Vibrio fischeri, Pseudomonas aeruginosa, and Staphylococcus aureus, and discuss various antivirulence strategies based on blocking different components of the QS machinery.
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Affiliation(s)
- Kerstin Reuter
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany.; Saarbrücken Graduate School of Computer Science, Saarland University, Saarbrücken, Germany
| | - Anke Steinbach
- Department of Drug Design and Optimization, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Saarbrücken, Germany
| | - Volkhard Helms
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany
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Selection of Single-Stranded DNA Molecular Recognition Elements against Exotoxin A Using a Novel Decoy-SELEX Method and Sensitive Detection of Exotoxin A in Human Serum. BIOMED RESEARCH INTERNATIONAL 2015; 2015:417641. [PMID: 26636098 PMCID: PMC4655287 DOI: 10.1155/2015/417641] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/09/2015] [Accepted: 10/12/2015] [Indexed: 12/04/2022]
Abstract
Exotoxin A is one of the virulence factors of Pseudomonas aeruginosa, a bacterium that can cause infections resulting in adverse health outcomes and increased burden to health care systems. Current methods of diagnosing P. aeruginosa infections are time consuming and can require significant preparation of patient samples. This study utilized a novel variation of the Systematic Evolution of Ligand by Exponential Enrichment, Decoy-SELEX, to identify an Exotoxin A specific single-stranded DNA (ssDNA) molecular recognition element (MRE). Its emphasis is on increasing stringency in directing binding toward free target of interest and at the same time decreasing binding toward negative targets. A ssDNA MRE with specificity and affinity was identified after fourteen rounds of Decoy-SELEX. Utilizing surface plasmon resonance measurements, the determined equilibrium dissociation constant (Kd) of the MRE is between 4.2 µM and 4.5 µM, and is highly selective for Exotoxin A over negative targets. A ssDNA MRE modified sandwich enzyme-linked immunosorbent assay (ELISA) has been developed and achieved sensitive detection of Exotoxin A at nanomolar concentrations in human serum. This study has demonstrated the proof-of-principle of using a ssDNA MRE as a clinical diagnostic tool.
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Xu J, Lee Y, Beamer LJ, Van Doren SR. Phosphorylation in the catalytic cleft stabilizes and attracts domains of a phosphohexomutase. Biophys J 2015; 108:325-37. [PMID: 25606681 DOI: 10.1016/j.bpj.2014.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 11/22/2014] [Accepted: 12/03/2014] [Indexed: 11/18/2022] Open
Abstract
Phosphorylation can modulate the activities of enzymes. The phosphoryl donor in the catalytic cleft of α-D-phosphohexomutases is transiently dephosphorylated while the reaction intermediate completes a 180° reorientation within the cleft. The phosphorylated form of 52 kDa bacterial phosphomannomutase/phosphoglucomutase is less accessible to dye or protease, more stable to chemical denaturation, and widely stabilized against NMR-detected hydrogen exchange across the core of domain 3 to juxtaposed domain 4 (each by ≥ 1.3 kcal/mol) and parts of domains 1 and 2. However, phosphorylation accelerates hydrogen exchange in specific regions of domains 1 and 2, including a metal-binding residue in the active site. Electrostatic field lines reveal attraction across the catalytic cleft between phosphorylated Ser-108 and domain 4, but repulsion when Ser-108 is dephosphorylated. Molecular dynamics (MD) simulated the dephosphorylated form to be expanded due to enhanced rotational freedom of domain 4. The contacts and fluctuations of the MD trajectories enabled correct simulation of more than 80% of sites that undergo either protection or deprotection from hydrogen exchange due to phosphorylation. Electrostatic attraction in the phosphorylated enzyme accounts for 1) domain 4 drawing closer to domains 1 and 3; 2) decreased accessibility; and 3) increased stability within these domains. The electrostriction due to phosphorylation may help capture substrate, whereas the opening of the cleft upon transient dephosphorylation allows rotation of the intermediate. The long-range effects of phosphorylation on hydrogen exchange parallel reports on protein kinases, suggesting a conceptual link among these multidomain, phosphoryl transfer enzymes.
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Affiliation(s)
- Jia Xu
- Department of Biochemistry, University of Missouri, Columbia, Missouri
| | - Yingying Lee
- Department of Biochemistry, University of Missouri, Columbia, Missouri
| | - Lesa J Beamer
- Department of Biochemistry, University of Missouri, Columbia, Missouri
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Pires DP, Vilas Boas D, Sillankorva S, Azeredo J. Phage Therapy: a Step Forward in the Treatment of Pseudomonas aeruginosa Infections. J Virol 2015; 89:7449-56. [PMID: 25972556 PMCID: PMC4505681 DOI: 10.1128/jvi.00385-15] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Antimicrobial resistance constitutes one of the major worldwide public health concerns. Bacteria are becoming resistant to the vast majority of antibiotics, and nowadays, a common infection can be fatal. To address this situation, the use of phages for the treatment of bacterial infections has been extensively studied as an alternative therapeutic strategy. Since Pseudomonas aeruginosa is one of the most common causes of health care-associated infections, many studies have reported the in vitro and in vivo antibacterial efficacy of phage therapy against this bacterium. This review collects data of all the P. aeruginosa phages sequenced to date, providing a better understanding about their biodiversity. This review further addresses the in vitro and in vivo results obtained by using phages to treat or prevent P. aeruginosa infections as well as the major hurdles associated with this therapy.
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Affiliation(s)
- Diana P Pires
- CEB-Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Braga, Portugal
| | - Diana Vilas Boas
- CEB-Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Braga, Portugal
| | - Sanna Sillankorva
- CEB-Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Braga, Portugal
| | - Joana Azeredo
- CEB-Centre of Biological Engineering, LIBRO-Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Braga, Portugal
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Single-Stranded DNA Aptamers against Pathogens and Toxins: Identification and Biosensing Applications. BIOMED RESEARCH INTERNATIONAL 2015. [PMID: 26199940 PMCID: PMC4493287 DOI: 10.1155/2015/419318] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Molecular recognition elements (MREs) can be short sequences of single-stranded DNA, RNA, small peptides, or antibody fragments. They can bind to user-defined targets with high affinity and specificity. There has been an increasing interest in the identification and application of nucleic acid molecular recognition elements, commonly known as aptamers, since they were first described in 1990 by the Gold and Szostak laboratories. A large number of target specific nucleic acids MREs and their applications are currently in the literature. This review first describes the general methodologies used in identifying single-stranded DNA (ssDNA) aptamers. It then summarizes advancements in the identification and biosensing application of ssDNA aptamers specific for bacteria, viruses, their associated molecules, and selected chemical toxins. Lastly, an overview of the basic principles of ssDNA aptamer-based biosensors is discussed.
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Stanton BA, Coutermarsh B, Barnaby R, Hogan D. Pseudomonas aeruginosa Reduces VX-809 Stimulated F508del-CFTR Chloride Secretion by Airway Epithelial Cells. PLoS One 2015; 10:e0127742. [PMID: 26018799 PMCID: PMC4446214 DOI: 10.1371/journal.pone.0127742] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 04/19/2015] [Indexed: 12/25/2022] Open
Abstract
Background P. aeruginosa is an opportunistic pathogen that chronically infects the lungs of 85% of adult patients with Cystic Fibrosis (CF). Previously, we demonstrated that P. aeruginosa reduced wt-CFTR Cl secretion by airway epithelial cells. Recently, a new investigational drug VX-809 has been shown to increase F508del-CFTR Cl secretion in human bronchial epithelial (HBE) cells, and, in combination with VX-770, to increase FEV1 (forced expiratory volume in 1 second) by an average of 3-5% in CF patients homozygous for the F508del-CFTR mutation. We propose that P. aeruginosa infection of CF lungs reduces VX-809 + VX-770- stimulated F508del-CFTR Cl secretion, and thereby reduces the clinical efficacy of VX-809 + VX-770. Methods and Results F508del-CFBE cells and primary cultures of CF-HBE cells (F508del/F508del) were exposed to VX-809 alone or a combination of VX-809 + VX-770 for 48 hours and the effect of P. aeruginosa on F508del-CFTR Cl secretion was measured in Ussing chambers. The effect of VX-809 on F508del-CFTR abundance was measured by cell surface biotinylation and western blot analysis. PAO1, PA14, PAK and 6 clinical isolates of P. aeruginosa (3 mucoid and 3 non-mucoid) significantly reduced drug stimulated F508del-CFTR Cl secretion, and plasma membrane F508del-CFTR. Conclusion The observation that P. aeruginosa reduces VX-809 and VX-809 + VX-770 stimulated F508del CFTR Cl secretion may explain, in part, why VX-809 + VX-770 has modest efficacy in clinical trials.
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Affiliation(s)
- Bruce A. Stanton
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- * E-mail:
| | - Bonita Coutermarsh
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Roxanna Barnaby
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Deborah Hogan
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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Ni I, Ji C, Vij N. Second-hand cigarette smoke impairs bacterial phagocytosis in macrophages by modulating CFTR dependent lipid-rafts. PLoS One 2015; 10:e0121200. [PMID: 25794013 PMCID: PMC4368805 DOI: 10.1371/journal.pone.0121200] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 01/27/2015] [Indexed: 01/08/2023] Open
Abstract
Introduction First/Second-hand cigarette-smoke (FHS/SHS) exposure weakens immune defenses inducing chronic obstructive pulmonary disease (COPD) but the underlying mechanisms are not fully understood. Hence, we evaluated if SHS induced changes in membrane/lipid-raft (m-/r)-CFTR (cystic fibrosis transmembrane conductance regulator) expression/activity is a potential mechanism for impaired bacterial phagocytosis in COPD. Methods RAW264.7 murine macrophages were exposed to freshly prepared CS-extract (CSE) containing culture media and/or Pseudomonas-aeruginosa-PA01-GFP for phagocytosis (fluorescence-microscopy), bacterial survival (colony-forming-units-CFU), and immunoblotting assays. The CFTR-expression/activity and lipid-rafts were modulated by transient-transfection or inhibitors/inducers. Next, mice were exposed to acute/sub-chronic-SHS or room-air (5-days/3-weeks) and infected with PA01-GFP, followed by quantification of bacterial survival by CFU-assay. Results We investigated the effect of CSE treatment on RAW264.7 cells infected by PA01-GFP and observed that CSE treatment significantly (p<0.01) inhibits PA01-GFP phagocytosis as compared to the controls. We also verified this in murine model, exposed to acute/sub-chronic-SHS and found significant (p<0.05, p<0.02) increase in bacterial survival in the SHS-exposed lungs as compared to the room-air controls. Next, we examined the effect of impaired CFTR ion-channel-activity on PA01-GFP infection of RAW264.7 cells using CFTR172-inhibitor and found no significant change in phagocytosis. We also similarly evaluated the effect of a CFTR corrector-potentiator compound, VRT-532, and observed no significant rescue of CSE impaired PA01-GFP phagocytosis although it significantly (p<0.05) decreases CSE induced bacterial survival. Moreover, induction of CFTR expression in macrophages significantly (p<0.03) improves CSE impaired PA01-GFP phagocytosis as compared to the control. Next, we verified the link between m-/r-CFTR expression and phagocytosis using methyl-β-cyclodextran (CD), as it is known to deplete CFTR from membrane lipid-rafts. We observed that CD treatment significantly (p<0.01) inhibits bacterial phagocytosis in RAW264.7 cells and adding CSE further impairs phagocytosis suggesting synergistic effect on CFTR dependent lipid-rafts. Conclusion Our data suggest that SHS impairs bacterial phagocytosis by modulating CFTR dependent lipid-rafts.
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Affiliation(s)
- Inzer Ni
- Department of Pediatric Respiratory Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Changhoon Ji
- Department of Pediatric Respiratory Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Neeraj Vij
- Department of Pediatric Respiratory Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Foundational Sciences, College of Medicine, Central Michigan University, Mount Pleasant, Michigan, United States of America
- * E-mail:
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Hilker R, Munder A, Klockgether J, Losada PM, Chouvarine P, Cramer N, Davenport CF, Dethlefsen S, Fischer S, Peng H, Schönfelder T, Türk O, Wiehlmann L, Wölbeling F, Gulbins E, Goesmann A, Tümmler B. Interclonal gradient of virulence in thePseudomonas aeruginosapangenome from disease and environment. Environ Microbiol 2014; 17:29-46. [DOI: 10.1111/1462-2920.12606] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 07/05/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Rolf Hilker
- Department of Bioinformatics and Systems Biology; University of Giessen; Gießen D-35392 Germany
| | - Antje Munder
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Jens Klockgether
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Patricia Moran Losada
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Philippe Chouvarine
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Nina Cramer
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Colin F. Davenport
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Sarah Dethlefsen
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Sebastian Fischer
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Huiming Peng
- Department of Molecular Biology; University Hospital Essen; University of Duisburg-Essen; Essen D-45122 Germany
| | - Torben Schönfelder
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Oliver Türk
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Lutz Wiehlmann
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Florian Wölbeling
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
| | - Erich Gulbins
- Department of Molecular Biology; University Hospital Essen; University of Duisburg-Essen; Essen D-45122 Germany
| | - Alexander Goesmann
- Department of Bioinformatics and Systems Biology; University of Giessen; Gießen D-35392 Germany
| | - Burkhard Tümmler
- Clinical Research Group; ‘Molecular Pathology of Cystic Fibrosis and Pseudomonas Genomics’; Hannover Medical School; OE 6710 Hannover D-30625 Germany
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH); German Center for Lung Research; Hannover Germany
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Epoxide-mediated differential packaging of Cif and other virulence factors into outer membrane vesicles. J Bacteriol 2014; 196:3633-42. [PMID: 25112474 DOI: 10.1128/jb.01760-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa produces outer membrane vesicles (OMVs) that contain a number of secreted bacterial proteins, including phospholipases, alkaline phosphatase, and the CFTR inhibitory factor (Cif). Previously, Cif, an epoxide hydrolase, was shown to be regulated at the transcriptional level by epoxides, which serve as ligands of the repressor, CifR. Here, we tested whether epoxides have an effect on Cif levels in OMVs. We showed that growth of P. aeruginosa in the presence of specific epoxides but not a hydrolysis product increased Cif packaging into OMVs in a CifR-independent fashion. The outer membrane protein, OprF, was also increased under these conditions, but alkaline phosphatase activity was not significantly altered. Additionally, we demonstrated that OMV shape and density were affected by epoxide treatment, with two distinct vesicle fractions present when cells were treated with epibromohydrin (EBH), a model epoxide. Vesicles isolated from the two density fractions exhibited different protein profiles in Western blotting and silver staining. We have shown that a variety of clinically or host-relevant treatments, including antibiotics, also alter the proteins packaged in OMVs. Proteomic analysis of purified OMVs followed by an analysis of transposon mutant OMVs yielded mutants with altered vesicle packaging. Finally, epithelial cell cytotoxicity was reduced in the vesicles formed in the presence of EBH, suggesting that this epoxide alters the function of the OMVs. Our data support a model whereby clinically or host-relevant signals mediate differential packaging of virulence factors in OMVs, which results in functional consequences for host-pathogen interactions.
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Mittal R, Grati M, Gerring R, Blackwelder P, Yan D, Li JD, Liu XZ. In vitro interaction of Pseudomonas aeruginosa with human middle ear epithelial cells. PLoS One 2014; 9:e91885. [PMID: 24632826 PMCID: PMC3954863 DOI: 10.1371/journal.pone.0091885] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 02/14/2014] [Indexed: 01/27/2023] Open
Abstract
Background Otitis media (OM) is an inflammation of the middle ear which can be acute or chronic. Acute OM is caused by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis whereas Pseudomonas aeruginosa is a leading cause of chronic suppurative otitis media (CSOM). CSOM is a chronic inflammatory disorder of the middle ear characterized by infection and discharge. The survivors often suffer from hearing loss and neurological sequelae. However, no information is available regarding the interaction of P. aeruginosa with human middle ear epithelial cells (HMEECs). Methodology and Findings In the present investigation, we demonstrate that P. aeruginosa is able to enter and survive inside HMEECs via an uptake mechanism that is dependent on microtubule and actin microfilaments. The actin microfilament disrupting agent as well as microtubule inhibitors exhibited significant decrease in invasion of HMEECs by P. aeruginosa. Confocal microscopy demonstrated F-actin condensation associated with bacterial entry. This recruitment of F-actin was transient and returned to normal distribution after bacterial internalization. Scanning electron microscopy demonstrated the presence of bacteria on the surface of HMEECs, and transmission electron microscopy confirmed the internalization of P. aeruginosa located in the plasma membrane-bound vacuoles. We observed a significant decrease in cell invasion of OprF mutant compared to the wild-type strain. P. aeruginosa induced cytotoxicity, as demonstrated by the determination of lactate dehydrogenase levels in culture supernatants of infected HMEECs and by a fluorescent dye-based assay. Interestingly, OprF mutant showed little cell damage compared to wild-type P. aeruginosa. Conclusions and Significance This study deciphered the key events in the interaction of P. aeruginosa with HMEECs in vitro and highlighted the role of bacterial outer membrane protein, OprF, in this process. Understanding the molecular mechanisms in the pathogenesis of CSOM will help in identifying novel targets to design effective therapeutic strategies and to prevent hearing loss.
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Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - M’hamed Grati
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Robert Gerring
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Patricia Blackwelder
- Center for Advanced Microscopy, University of Miami, Coral Gables, Florida, United States of America
- RSMAS, University of Miami, Key Biscayne, Florida, United States of America
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Jian-Dong Li
- Center for Inflammation, Immunity, and Infection and Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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Garnett JP, Gray MA, Tarran R, Brodlie M, Ward C, Baker EH, Baines DL. Elevated paracellular glucose flux across cystic fibrosis airway epithelial monolayers is an important factor for Pseudomonas aeruginosa growth. PLoS One 2013; 8:e76283. [PMID: 24124542 PMCID: PMC3790714 DOI: 10.1371/journal.pone.0076283] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 08/22/2013] [Indexed: 01/17/2023] Open
Abstract
People with cystic fibrosis (CF) who develop related diabetes (CFRD) have accelerated pulmonary decline, increased infection with antibiotic-resistant Pseudomonas aeruginosa and increased pulmonary exacerbations. We have previously shown that glucose concentrations are elevated in airway surface liquid (ASL) of people with CF, particularly in those with CFRD. We therefore explored the hypotheses that glucose homeostasis is altered in CF airway epithelia and that elevation of glucose flux into ASL drives increased bacterial growth, with an effect over and above other cystic fibrosis transmembrane conductance regulator (CFTR)-related ASL abnormalities. The aim of this study was to compare the mechanisms governing airway glucose homeostasis in CF and non-CF primary human bronchial epithelial (HBE) monolayers, under normal conditions and in the presence of Ps. aeruginosa filtrate. HBE-bacterial co-cultures were performed in the presence of 5 mM or 15 mM basolateral glucose to investigate how changes in blood glucose, such as those seen in CFRD, affects luminal Ps. aeruginosa growth. Calu-3 cell monolayers were used to evaluate the potential importance of glucose on Ps. aeruginosa growth, in comparison to other hallmarks of the CF ASL, namely mucus hyperviscosity and impaired CFTR-dependent fluid secretions. We show that elevation of basolateral glucose promotes the apical growth of Ps. aeruginosa on CF airway epithelial monolayers more than non-CF monolayers. Ps. aeruginosa secretions elicited more glucose flux across CF airway epithelial monolayers compared to non-CF monolayers which we propose increases glucose availability in ASL for bacterial growth. In addition, elevating basolateral glucose increased Ps. aeruginosa growth over and above any CFTR-dependent effects and the presence or absence of mucus in Calu-3 airway epithelia-bacteria co-cultures. Together these studies highlight the importance of glucose as an additional factor in promoting Ps. aeruginosa growth and respiratory infection in CF disease.
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Affiliation(s)
- James P. Garnett
- Division of Biomedical Sciences, St George's University of London, London, United Kingdom
| | - Michael A. Gray
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Robert Tarran
- Cystic Fibrosis/Pulmonary Research and Treatment Centre, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Malcolm Brodlie
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Christopher Ward
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Emma H. Baker
- Division of Biomedical Sciences, St George's University of London, London, United Kingdom
| | - Deborah L. Baines
- Division of Biomedical Sciences, St George's University of London, London, United Kingdom
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