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Fardelli E, Di Gioacchino M, Lucidi M, Capecchi G, Bruni F, Sodo A, Visca P, Capellini G. Evidence of Correlation between Membrane Phase Transition and Clonogenicity in Dehydrating Acinetobacter baumannii: A Combined Micro-Raman and AFM Study. J Phys Chem B 2024. [PMID: 38959442 DOI: 10.1021/acs.jpcb.4c01246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The Gram-negative bacterium Acinetobacter baumannii is one of the most resilient multidrug-resistant pathogens in hospitals. Among Gram-negative bacteria, it is particularly resistant to dehydration (anhydrobiosis), and this feature allows A. baumannii to persist in hospital environments for long periods, subjected to unfavorable conditions. We leverage the combination of μ-Raman spectroscopy and atomic force microscopy (AFM) to investigate the anhydrobiotic mechanisms in A. baumannii cells by monitoring the membrane (both inner and outer membranes) properties of four A. baumannii strains during a 16-week dehydration period and in response to temperature excursions. We noted that the membranes of A. baumannii remained intact during the dehydration period despite undergoing a liquid-crystal-to-gel-phase transition, accompanied by changes in the mechanical properties of the membrane. This was evident from the AFM images, which showed the morphology of the bacterial cells alongside modifications of their superficial mechanical properties, and from the alteration in the intensity ratio of μ-Raman features linked to the CH3 and CH2 symmetric stretching modes. Furthermore, employing a universal power law revealed a significant correlation between this ratio and bacterial fitness across all tested strains. Additionally, we subjected dry A. baumannii to a temperature-dependent experiment, the results of which supported the correlation between the Raman ratio and culturability, demonstrating that the phase transition becomes irreversible when A. baumannii cells undergo different temperature cycles. Besides the relevance to the present study, we argue that μ-Raman can be used as a powerful nondestructive tool to assess the health status of bacterial cells based on membrane properties with a relatively high throughput.
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Affiliation(s)
- Elisa Fardelli
- Dipartimento di Scienze, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Rome, Italy
| | - Michael Di Gioacchino
- Dipartimento di Scienze, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Rome, Italy
| | - Massimiliano Lucidi
- Dipartimento di Scienze, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Rome, Italy
- National Biodiversity Future Center, piazza Marina 61, 90133 Palermo, Italy
| | - Giulia Capecchi
- Dipartimento di Scienze, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Rome, Italy
| | - Fabio Bruni
- Dipartimento di Scienze, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Rome, Italy
| | - Armida Sodo
- Dipartimento di Scienze, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Rome, Italy
| | - Paolo Visca
- Dipartimento di Scienze, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Rome, Italy
- Fondazione Santa Lucia, Via Ardeatina, 306/354, 00179 Rome, Italy
| | - Giovanni Capellini
- Dipartimento di Scienze, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Rome, Italy
- IHP Leibniz Institut für innovative Mikroelektronik, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany
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2
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Khorsand FR, Uversky VN. Liquid-liquid phase separation as triggering factor of fibril formation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2024; 206:143-182. [PMID: 38811080 DOI: 10.1016/bs.pmbts.2024.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Liquid-liquid phase separation (LLPS) refers to the phenomenon, where a homogeneous solution spontaneously undergoes a transition into two or more immiscible phases. Through transient weak multivalent macromolecular interactions, a homogeneous solution can spontaneously separate into two phases: one rich in biomolecules and the other poor in biomolecules. Phase separation is believed to serve as the physicochemical foundation for the formation of membrane-less organelles (MLOs) and bio-molecular condensates within cells. Moreover, numerous biological processes depend on LLPS, such as transcription, immunological response, chromatin architecture, DNA damage response, stress granule formation, viral infection, etc. Abnormalities in phase separation can lead to diseases, such as cancer, neurodegeneration, and metabolic disorders. LLPS is regulated by various factors, such as concentration of molecules undergoing LLPS, salt concentration, pH, temperature, post-translational modifications, and molecular chaperones. Recent research on LLPS of biomolecules has progressed rapidly and led to the development of databases containing information pertaining to various aspects of the biomolecule separation analysis. However, more comprehensive research is still required to fully comprehend the specific molecular mechanisms and biological effects of LLPS.
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Affiliation(s)
| | - Vladimir N Uversky
- Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Institute for Biological Instrumentation, Pushchino, Moscow, Russia; Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States.
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3
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Claudia MV, Javiera AA, Sebastián NS, José FR, Gloria L. Interplay between desiccation and oxidative stress responses in iron-oxidizing acidophilic bacteria. J Biotechnol 2024; 383:64-72. [PMID: 38311245 DOI: 10.1016/j.jbiotec.2024.01.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 01/15/2024] [Accepted: 01/30/2024] [Indexed: 02/10/2024]
Abstract
Variations in water availability represent a foremost stress factor affecting the growth and survival of microorganisms. Acidophilic bioleaching bacteria are industrially applied for releasing metals from mineral sulphides, and they are considered extremely tolerant to oxidative conditions prevailing in acidic bioleaching environments. Such processes usually are performed in heaps and thus these microorganisms are also exposed to intermittent desiccations or high osmolarity periods that reduce the water availability. However, the tolerance to water stress and the molecular basis of adaptation to it are still largely unknown. The aim of this work was to determine the cellular response to desiccation stress and establish its relationship to oxidative stress response in the acidophilic iron-oxidizing bacteria Acidithiobacillus ferrooxidans ATCC 23270 and Leptospirillum ferriphilum DSM 14647. Results showed that the exposure of cell cultures to desiccation (0-120 min) led to a significant reduction in cell growth, and to an increase in content in reactive oxygen species in both bacteria. However, Leptospirillum ferriphilum turned out to be more tolerant than Acidithiobacillus ferrooxidans. In addition, the pre-treatment of the cell cultures with compatible solutes (trehalose and ectoine), and antioxidants (glutathione and cobalamin) restored all stress parameters to levels exhibited by the control cultures. To evaluate the role of the osmotic and redox homeostasis mechanisms in coping with desiccation stress, the relative expression of a set of selected genes was approached by RT-qPCR experiments in cells exposed to desiccation for 30 min. Results showed a generalized upregulation of genes that code for mechanosensitive channels, and enzymes related to the biosynthesis of compatible solutes and oxidative stress response in both bacteria. These data suggest that acidophiles show variable tolerance to desiccation and allow to establish that water stress can trigger oxidative stress, and thus anti-oxidative protection capability can be a relevant mechanism when cells are challenged by desiccation or other anhydrobiosis states.
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Affiliation(s)
- Muñoz-Villagrán Claudia
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile
| | - Acevedo-Arbunic Javiera
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile
| | - Navarro-Salazar Sebastián
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile
| | - Fuentes-Rubio José
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile
| | - Levicán Gloria
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins, Santiago 3363, Chile.
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4
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Stojowska-Swędrzyńska K, Kuczyńska-Wiśnik D, Laskowska E. Influence of N ε-Lysine Acetylation on the Formation of Protein Aggregates and Antibiotic Persistence in E. coli. Molecules 2024; 29:383. [PMID: 38257296 PMCID: PMC10819833 DOI: 10.3390/molecules29020383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/07/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Numerous studies indicate that reversible Nε-lysine acetylation in bacteria may play a key role in the regulation of metabolic processes, transcription and translation, biofilm formation, virulence, and drug resistance. Using appropriate mutant strains deficient in non-enzymatic acetylation and enzymatic acetylation or deacetylation pathways, we investigated the influence of protein acetylation on cell viability, protein aggregation, and persister formation in Escherichia coli. Lysine acetylation was found to increase protein aggregation and cell viability under the late stationary phase. Moreover, increased lysine acetylation stimulated the formation of persisters. These results suggest that acetylation-dependent aggregation may improve the survival of bacteria under adverse conditions (such as the late stationary phase) and during antibiotic treatment. Further experiments revealed that acetylation-favorable conditions may increase persister formation in Klebsiella pneumoniae clinical isolate. However, the exact mechanisms underlying the relationship between acetylation and persistence in this pathogen remain to be elucidated.
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Affiliation(s)
| | | | - Ewa Laskowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (K.S.-S.); (D.K.-W.)
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5
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Azaiez S, Haenni M, Cheikh AB, Chalbi MS, Messaoudi A, Tilouch L, Bahri S, Drapeau A, Saras E, Mtibâa M, Zouaoui R, Said H, Madec JY, Lupo A, Mansour W. Healthcare Equipment and Personnel Reservoirs of Carbapenem-Resistant Acinetobacter baumannii Epidemic Clones in Intensive Care Units in a Tunisian Hospital. Microorganisms 2023; 11:2637. [PMID: 38004649 PMCID: PMC10672855 DOI: 10.3390/microorganisms11112637] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/18/2023] [Accepted: 10/19/2023] [Indexed: 11/26/2023] Open
Abstract
Carbapenem-resistant Acinetobacter baumannii (CRAB) strains can cause severe and difficult-to-treat infections in patients with compromised general health. CRAB strains disseminate rapidly in nosocomial settings by patient-to-patient contact, through medical devices and inanimate reservoirs. The occurrence of CRAB in patients residing in the intensive care units (ICUs) of the Sahloul University hospital in Sousse, Tunisia is high. The objective of the current study was to determine whether the surfaces of items present in five ICU wards and the medical personnel there operating could serve as reservoirs for CRAB strains. Furthermore, CRAB isolates from patients residing in the ICUs during the sampling campaign were analyzed for genome comparison with isolates from the ICUs environment. Overall, 206 items were screened for CRAB presence and 27 (14%) were contaminated with a CRAB isolate. The items were located in several areas of three ICUs. Eight of the 54 (15%) screened people working in the wards were colonized by CRAB on the hands. Patients residing in the ICUs were infected with CRAB strains sharing extensive genomic similarity with strains recovered in the nosocomial environment. The strains belonged to three sub-clades of the internationally disseminated clone (ST2). A clone emerging in the Mediterranean basin (ST85) was detected as well. The strains were OXA-23 or NDM-1 producers and were also pan-aminoglycoside resistant due to the presence of the armA gene. Hygiene measures are urgent to be implemented in the Sahloul hospital to avoid further spread of difficult-to-treat CRAB strains and preserve health of patients and personnel operating in the ICU wards.
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Affiliation(s)
- Sana Azaiez
- Laboratoire de Recherche Biophysique Métabolique et Pharmacologie Appliquée, LR12ES02, Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia; (S.A.); (A.M.); (S.B.); (M.M.); (R.Z.)
| | - Marisa Haenni
- Unité Antibiorésistance et Virulence Bactériennes, ANSES—Université de Lyon, 69007 Lyon, France; (M.H.); (A.D.); (E.S.); (J.-Y.M.)
| | - Asma Ben Cheikh
- Departement of Prevention and Security of Care, Sahloul University Hospital of Sousse, Sousse 4054, Tunisia; (A.B.C.); (M.S.C.); (H.S.)
- Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia
| | - Mohamed Sahbi Chalbi
- Departement of Prevention and Security of Care, Sahloul University Hospital of Sousse, Sousse 4054, Tunisia; (A.B.C.); (M.S.C.); (H.S.)
- Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia
| | - Aziza Messaoudi
- Laboratoire de Recherche Biophysique Métabolique et Pharmacologie Appliquée, LR12ES02, Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia; (S.A.); (A.M.); (S.B.); (M.M.); (R.Z.)
| | - Lamia Tilouch
- Laboratoire de Microbiologie Sahloul, University Hospital of Sousse, Sousse 4054, Tunisia;
- Faculté de Pharmacie, Université de Monastir, Monastir 5019, Tunisia
| | - Sana Bahri
- Laboratoire de Recherche Biophysique Métabolique et Pharmacologie Appliquée, LR12ES02, Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia; (S.A.); (A.M.); (S.B.); (M.M.); (R.Z.)
| | - Antoine Drapeau
- Unité Antibiorésistance et Virulence Bactériennes, ANSES—Université de Lyon, 69007 Lyon, France; (M.H.); (A.D.); (E.S.); (J.-Y.M.)
| | - Estelle Saras
- Unité Antibiorésistance et Virulence Bactériennes, ANSES—Université de Lyon, 69007 Lyon, France; (M.H.); (A.D.); (E.S.); (J.-Y.M.)
| | - Mariem Mtibâa
- Laboratoire de Recherche Biophysique Métabolique et Pharmacologie Appliquée, LR12ES02, Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia; (S.A.); (A.M.); (S.B.); (M.M.); (R.Z.)
| | - Rania Zouaoui
- Laboratoire de Recherche Biophysique Métabolique et Pharmacologie Appliquée, LR12ES02, Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia; (S.A.); (A.M.); (S.B.); (M.M.); (R.Z.)
| | - Houyem Said
- Departement of Prevention and Security of Care, Sahloul University Hospital of Sousse, Sousse 4054, Tunisia; (A.B.C.); (M.S.C.); (H.S.)
- Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia
| | - Jean-Yves Madec
- Unité Antibiorésistance et Virulence Bactériennes, ANSES—Université de Lyon, 69007 Lyon, France; (M.H.); (A.D.); (E.S.); (J.-Y.M.)
| | - Agnese Lupo
- Unité Antibiorésistance et Virulence Bactériennes, ANSES—Université de Lyon, 69007 Lyon, France; (M.H.); (A.D.); (E.S.); (J.-Y.M.)
| | - Wejdene Mansour
- Laboratoire de Recherche Biophysique Métabolique et Pharmacologie Appliquée, LR12ES02, Faculté de Médecine Ibn Al Jazzar Sousse, Université de Sousse, Sousse 4002, Tunisia; (S.A.); (A.M.); (S.B.); (M.M.); (R.Z.)
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6
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Kuczyńska-Wiśnik D, Stojowska-Swędrzyńska K, Laskowska E. Liquid-Liquid Phase Separation and Protective Protein Aggregates in Bacteria. Molecules 2023; 28:6582. [PMID: 37764358 PMCID: PMC10534466 DOI: 10.3390/molecules28186582] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/09/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) and the formation of membraneless organelles (MLOs) contribute to the spatiotemporal organization of various physiological processes in the cell. These phenomena have been studied and characterized mainly in eukaryotic cells. However, increasing evidence indicates that LLPS-driven protein condensation may also occur in prokaryotes. Recent studies indicate that aggregates formed during proteotoxic stresses may also play the role of MLOs and increase the fitness of bacteria under stress. The beneficial effect of aggregates may result from the sequestration and protection of proteins against irreversible inactivation or degradation, activation of the protein quality control system and induction of dormancy. The most common stress that bacteria encounter in the natural environment is water loss. Therefore, in this review, we focus on protein aggregates formed in E. coli upon desiccation-rehydration stress. In silico analyses suggest that various mechanisms and interactions are responsible for their formation, including LLPS, disordered sequences and aggregation-prone regions. These data support findings that intrinsically disordered proteins and LLPS may contribute to desiccation tolerance not only in eukaryotic cells but also in bacteria. LLPS-driven aggregation may be a strategy used by pathogens to survive antibiotic treatment and desiccation stress in the hospital environment.
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Affiliation(s)
| | | | - Ewa Laskowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (D.K.-W.); (K.S.-S.)
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7
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Knauf G, Groover KE, O’Donnell AC, Davies BW. Generation of Synthetic Acinetobacter baumannii-Specific Nanobodies. ACS Infect Dis 2023; 9:1190-1195. [PMID: 37162304 PMCID: PMC10262196 DOI: 10.1021/acsinfecdis.3c00024] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Indexed: 05/11/2023]
Abstract
The bacterial pathogen Acinetobacter baumannii is a leading cause of drug-resistant infections. Here, we investigated the potential of developing nanobodies that can recognize A. baumannii over other Gram-negative bacteria. Through generation and panning of a synthetic nanobody library, we identified several potential lead candidates. We demonstrate how incorporation of next-generation sequencing analysis can aid in the selection of lead candidate nanobodies. Using monoclonal phage display, we validated the binding of lead nanobodies to A. baumannii. Subsequent purification and biochemical characterization revealed one particularly robust nanobody that specifically bound select A. baumannii strains compared to other common drug-resistant pathogens. These findings support the potential for nanobodies to selectively target A. baumannii and the identification of lead candidates for future investigation.
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Affiliation(s)
- Gregory
A. Knauf
- Department
of Molecular Biosciences, The University
of Texas at Austin, Austin, Texas 78712, USA
| | - Kyra E. Groover
- Department
of Molecular Biosciences, The University
of Texas at Austin, Austin, Texas 78712, USA
| | - Angela C. O’Donnell
- Department
of Molecular Biosciences, The University
of Texas at Austin, Austin, Texas 78712, USA
- John
Ring LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Bryan W. Davies
- Department
of Molecular Biosciences, The University
of Texas at Austin, Austin, Texas 78712, USA
- John
Ring LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, Texas 78712, USA
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8
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Nunez C, Kostoulias X, Peleg A, Short F, Qu Y. A comprehensive comparison of biofilm formation and capsule production for bacterial survival on hospital surfaces. Biofilm 2023; 5:100105. [PMID: 36711324 PMCID: PMC9880390 DOI: 10.1016/j.bioflm.2023.100105] [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: 12/03/2022] [Revised: 01/16/2023] [Accepted: 01/20/2023] [Indexed: 01/23/2023] Open
Abstract
Biofilm formation and capsule production are known microbial strategies used by bacterial pathogens to survive adverse conditions in the hospital environment. The relative importance of these strategies individually is unexplored. This project aims to compare the contributory roles of biofilm formation and capsule production in bacterial survival on hospital surfaces. Representative strains of bacterial species often causing hospital-acquired infections were selected, including Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. The importance of biofilm formation and capsule production on bacterial survival was evaluated by comparing capsule-positive wild-type and capsule-deficient mutant strains, and biofilm and planktonic growth modes respectively, against three adverse hospital conditions, including desiccation, benzalkonium chloride disinfection and ultraviolet (UV) radiation. Bacterial survival was quantitatively assessed using colony-forming unit (CFU) enumeration and the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay and qualitatively by scanning electron microscopy (SEM). Correlations between capsule production and biofilm formation were further investigated. Biofilm formation contributed significantly to bacterial survival on hospital surface simulators, mediating high resistance to desiccation, benzalkonium chloride disinfection and UV radiation. The role of capsule production was minor and species-specific; encapsulated A. baumannii but not K. pneumoniae cells demonstrated slightly increased resistance to desiccation, and neither showed enhanced resistance to benzalkonium chloride. Interestingly, capsule production sensitized K. pneumoniae and A. baumannii to UV radiation. The loss of capsule in K. pneumoniae and A. baumannii enhanced biofilm formation, possibly by increasing cell surface hydrophobicity. In summary, this study confirms the crucial role of biofilm formation in bacterial survival on hospital surfaces. Conversely, encapsulation plays a relatively minor role and may even negatively impact bacterial biofilm formation and hospital survival.
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Affiliation(s)
- Charles Nunez
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Xenia Kostoulias
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Anton Peleg
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Francesca Short
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia,Corresponding author.,
| | - Yue Qu
- Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia,Corresponding author. Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia.
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9
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Wang H, Shen J, Ma K, Zhu C, Fang M, Hou X, Zhang S, Wang W, Xue T. Transcriptome analysis revealed the role of capsular polysaccharides in desiccation tolerance of foodborne Staphylococcus aureus. Food Res Int 2022; 159:111602. [DOI: 10.1016/j.foodres.2022.111602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 11/04/2022]
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10
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Genome-Wide Identification of Pseudomonas aeruginosa Genes Important for Desiccation Tolerance on Inanimate Surfaces. mSystems 2022; 7:e0011422. [PMID: 35469420 PMCID: PMC9239045 DOI: 10.1128/msystems.00114-22] [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] [Indexed: 11/24/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen prevalent in the environment and in health care settings. Transmission in the health care setting occurs through human-human interactions and/or contact with contaminated surfaces. Moist surfaces such as respirators, sink and tub drains, and even disinfectants can serve as reservoirs. Dry surfaces such as plastic and stainless steel could also serve as a reservoir but would necessitate some degree of tolerance to desiccation. Using an assay to measure P. aeruginosa tolerance to desiccation on plastic and stainless-steel surfaces, we found that only 0.05 to 0.1% of the desiccated cells could be recovered 24 h postdesiccation. We took advantage of the strong selection imposed by desiccation to identify genes important for tolerance using Tn-seq. A highly saturated Tn-seq library was desiccated on plastic and stainless-steel surfaces. NexGen sequencing of the recovered cells identified 97 genes important for survival. Comparing cells desiccated under low- and high-nutrient conditions allowed for differentiation of genes important for desiccation tolerance. The 53 genes identified in the latter analysis are involved in maintenance of cell envelope integrity, purine and pyrimidine biosynthesis, tricarboxylic acid (TCA) cycle, and the hydrolysis of misfolded proteins. The Tn-seq findings were validated by competition experiments with wild-type (WT) cells and select Tn insertion mutants. Mutants lacking carB and surA demonstrated the largest fitness defects, indicating that pyrimidine biosynthesis and outer membrane integrity are essential for desiccation tolerance. Increased understanding of desiccation tolerance could provide insight into approaches to control environmental reservoirs of P. aeruginosa. IMPORTANCE Health care-associated infections (HAIs) caused by Pseudomonas aeruginosa result in significant morbidity and mortality and are a significant economic burden. Moist environments that promote biofilm formation are an important reservoir for P. aeruginosa. Dry environments may also serve as a reservoir but would require some degree of desiccation tolerance. Here, we took a genome-wide approach to identify genes important for desiccation tolerance on plastic and stainless-steel surfaces. Genes involved in assembly of outer membrane proteins and pyrimidine biosynthesis were particularly important. Strains lacking these functions were unable to tolerate surface desiccation. These findings suggest that inhibitors of these pathways could be used to prevent P. aeruginosa survival on dry surfaces.
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11
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Bacterial hydrophilins promote pathogen desiccation tolerance. Cell Host Microbe 2022; 30:975-987.e7. [PMID: 35413266 DOI: 10.1016/j.chom.2022.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/14/2022] [Accepted: 03/17/2022] [Indexed: 11/21/2022]
Abstract
Acinetobacter baumannii is a leading cause of hospital-acquired infections, where outbreaks are driven by its ability to persist on surfaces in a desiccated state. Here, we show that A. baumannii causes more virulent pneumonia following desiccation and profile the genetic requirements for desiccation. We find that desiccation tolerance is enhanced upon the disruption of Lon protease, which targets unfolded and aggregated proteins for degradation. Notably, two bacterial hydrophilins, DtpA and DtpB, are transcriptionally upregulated in Δlon via the two-component regulator, BfmR. These proteins, both hydrophilic and intrinsically disordered, promote desiccation tolerance in A. baumannii. Additionally, recombinant DtpA protects purified enzymes from inactivation and improves the desiccation tolerance of a probiotic bacterium when heterologously expressed. These results demonstrate a connection between environmental persistence and pathogenicity in A. baumannii, provide insight into the mechanisms of extreme desiccation tolerance, and reveal potential applications for bacterial hydrophilins in the preservation of protein- and live bacteria-based pharmaceuticals.
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12
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CsrA-Controlled Proteins Reveal New Dimensions of Acinetobacter baumannii Desiccation Tolerance. J Bacteriol 2022; 204:e0047921. [PMID: 35285725 DOI: 10.1128/jb.00479-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Hospital environments are excellent reservoirs for the opportunistic pathogen Acinetobacter baumannii in part because it is exceptionally tolerant to desiccation. We found that relative to other A. baumannii strains, the virulent strain AB5075 was strikingly desiccation resistant at 2% relative humidity (RH), suggesting that it is a good model for studies of the functional basis of this trait. Consistent with results from other A. baumannii strains at 40% RH, we found the global posttranscriptional regulator CsrA to be critically important for desiccation tolerance of AB5075 at 2% RH. Proteomics experiments identified proteins that were differentially present in wild-type and csrA mutant cells. Subsequent analysis of mutants in genes encoding some of these proteins revealed six genes that were required for wild-type levels of desiccation tolerance. These include genes for catalase, a universal stress protein, a hypothetical protein, and a biofilm-associated protein. Two genes of unknown function had very strong desiccation phenotypes, with one of the two genes predicting an intrinsically disordered protein (IDP) that binds to DNA. Intrinsically disordered proteins are widespread in eukaryotes but less so in prokaryotes. Our results suggest there are new mechanisms underlying desiccation tolerance in bacteria and identify several key functions involved. IMPORTANCE Acinetobacter baumannii is found in terrestrial environments but can cause nosocomial infections in very sick patients. A factor that contributes to the prevalence of A. baumannii in hospital settings is that it is intrinsically resistant to dry conditions. Here, we established the virulent strain A. baumannii AB5075 as a model for studies of desiccation tolerance at very low relative humidity. Our results show that this trait depends on two proteins of unknown function, one of which is predicted to be an intrinsically disordered protein. This category of protein is critical for the small animals named tardigrades to survive desiccation. Our results suggest that A. baumannii may have novel strategies to survive desiccation that have not previously been seen in bacteria.
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Santana de Carvalho D, Trovatti Uetanabaro AP, Kato RB, Aburjaile FF, Jaiswal AK, Profeta R, De Oliveira Carvalho RD, Tiwar S, Cybelle Pinto Gomide A, Almeida Costa E, Kukharenko O, Orlovska I, Podolich O, Reva O, Ramos PIP, De Carvalho Azevedo VA, Brenig B, Andrade BS, de Vera JPP, Kozyrovska NO, Barh D, Góes-Neto A. The Space-Exposed Kombucha Microbial Community Member Komagataeibacter oboediens Showed Only Minor Changes in Its Genome After Reactivation on Earth. Front Microbiol 2022; 13:782175. [PMID: 35369445 PMCID: PMC8970348 DOI: 10.3389/fmicb.2022.782175] [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: 09/23/2021] [Accepted: 02/01/2022] [Indexed: 11/23/2022] Open
Abstract
Komagataeibacter is the dominant taxon and cellulose-producing bacteria in the Kombucha Microbial Community (KMC). This is the first study to isolate the K. oboediens genome from a reactivated space-exposed KMC sample and comprehensively characterize it. The space-exposed genome was compared with the Earth-based reference genome to understand the genome stability of K. oboediens under extraterrestrial conditions during a long time. Our results suggest that the genomes of K. oboediens IMBG180 (ground sample) and K. oboediens IMBG185 (space-exposed) are remarkably similar in topology, genomic islands, transposases, prion-like proteins, and number of plasmids and CRISPR-Cas cassettes. Nonetheless, there was a difference in the length of plasmids and the location of cas genes. A small difference was observed in the number of protein coding genes. Despite these differences, they do not affect any genetic metabolic profile of the cellulose synthesis, nitrogen-fixation, hopanoid lipids biosynthesis, and stress-related pathways. Minor changes are only observed in central carbohydrate and energy metabolism pathways gene numbers or sequence completeness. Altogether, these findings suggest that K. oboediens maintains its genome stability and functionality in KMC exposed to the space environment most probably due to the protective role of the KMC biofilm. Furthermore, due to its unaffected metabolic pathways, this bacterial species may also retain some promising potential for space applications.
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Affiliation(s)
- Daniel Santana de Carvalho
- Laboratory of Molecular and Computational Biology of Fungi, Department of Microbiology, Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ana Paula Trovatti Uetanabaro
- Laboratory of Molecular and Computational Biology of Fungi, Department of Microbiology, Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Postgraduate Program in Biology and Biotechnology of Microorganisms, Department of Biological Sciences, State University of Santa Cruz, Ilhéus, Brazil
| | - Rodrigo Bentes Kato
- Laboratory of Molecular and Computational Biology of Fungi, Department of Microbiology, Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Flávia Figueira Aburjaile
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Arun Kumar Jaiswal
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Rodrigo Profeta
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Rodrigo Dias De Oliveira Carvalho
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sandeep Tiwar
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Anne Cybelle Pinto Gomide
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Eduardo Almeida Costa
- Computational Biology and Biotechnological Information Management Center (NBCGIB), State University of Santa Cruz, Ilhéus, Brazil
| | - Olga Kukharenko
- Institute of Molecular Biology and Genetics of NASU, Kyiv, Ukraine
| | - Iryna Orlovska
- Institute of Molecular Biology and Genetics of NASU, Kyiv, Ukraine
| | - Olga Podolich
- Institute of Molecular Biology and Genetics of NASU, Kyiv, Ukraine
| | - Oleg Reva
- Department of Biochemistry, Genetics and Microbiology, Centre for Bioinformatics and Computational Biology, University of Pretoria, Pretoria, South Africa
| | - Pablo Ivan P. Ramos
- Center for Data and Knowledge Integration for Health (CIDACS), Institute Gonçalo Moniz, Oswaldo Cruz Foundation (FIOCRUZ-Bahia), Salvador, Brazil
| | - Vasco Ariston De Carvalho Azevedo
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Bertram Brenig
- Institute of Veterinary Medicine, Burckhardtweg, University of Göttingen, Göttingen, Germany
| | - Bruno Silva Andrade
- Laboratory of Bioinformatics and Computational Chemistry, Department of Biological Sciences, State University of Southwest Bahia (UESB), Jequié, Brazil
| | - Jean-Pierre P. de Vera
- German Aerospace Center (DLR) Berlin, Institute of Planetary Research, Planetary Laboratories, Astrobiological Laboratories, Berlin, Germany
| | | | - Debmalya Barh
- Laboratory of Cellular and Molecular Genetics, Department of Genetics, Ecology and Evolution, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology, Purba Medinipur, India
| | - Aristóteles Góes-Neto
- Laboratory of Molecular and Computational Biology of Fungi, Department of Microbiology, Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Singh R, Capalash N, Sharma P. Vaccine development to control the rising scourge of antibiotic-resistant Acinetobacter baumannii: a systematic review. 3 Biotech 2022; 12:85. [PMID: 35261870 PMCID: PMC8890014 DOI: 10.1007/s13205-022-03148-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 02/11/2022] [Indexed: 03/02/2023] Open
Abstract
Acinetobacter baumannii has emerged as one of major nosocomial pathogen and global emergence of multidrug-resistant strains has become a challenge for developing effective treatment options. A. baumannii has developed resistance to almost all the antibiotics viz. beta-lactams, carbapenems, tigecycline and now colistin, a last resort of antibiotics. The world is on the cusp of post antibiotic era and the evolution of multi-, extreme- and pan–drug-resistant A. baumannii strains is its obvious harbinger. Various combinations of antibiotics have been investigated but no successful treatment option is available. All these failed efforts have led researchers to develop and implement prophylactic vaccination for the prevention of infections caused by this pathogen. In this review, the advantages and disadvantages of active and passive immunization, the types of sub-unit and multi-component vaccine candidates investigated against A. baumannii viz. whole cell organism, outer membrane vesicles, outer membrane complexes, conjugate vaccines and sub-unit vaccines have been discussed. In addition, the benefits of Reverse vaccinology are emphasized here in which the potential vaccine candidates are predicted using bioinformatic online tools prior to in vivo validations.
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Acinetobacter baumannii: An Ancient Commensal with Weapons of a Pathogen. Pathogens 2021; 10:pathogens10040387. [PMID: 33804894 PMCID: PMC8063835 DOI: 10.3390/pathogens10040387] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 12/22/2022] Open
Abstract
Acinetobacter baumannii is regarded as a life-threatening pathogen associated with community-acquired and nosocomial infections, mainly pneumonia. The rise in the number of A. baumannii antibiotic-resistant strains reduces effective therapies and increases mortality. Bacterial comparative genomic studies have unraveled the innate and acquired virulence factors of A. baumannii. These virulence factors are involved in antibiotic resistance, environmental persistence, host-pathogen interactions, and immune evasion. Studies on host–pathogen interactions revealed that A. baumannii evolved different mechanisms to adhere to in order to invade host respiratory cells as well as evade the host immune system. In this review, we discuss current data on A. baumannii genetic features and virulence factors. An emphasis is given to the players in host–pathogen interaction in the respiratory tract. In addition, we report recent investigations into host defense systems using in vitro and in vivo models, providing new insights into the innate immune response to A. baumannii infections. Increasing our knowledge of A. baumannii pathogenesis may help the development of novel therapeutic strategies based on anti-adhesive, anti-virulence, and anti-cell to cell signaling pathways drugs.
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Monem S, Furmanek-Blaszk B, Łupkowska A, Kuczyńska-Wiśnik D, Stojowska-Swędrzyńska K, Laskowska E. Mechanisms Protecting Acinetobacter baumannii against Multiple Stresses Triggered by the Host Immune Response, Antibiotics and Outside-Host Environment. Int J Mol Sci 2020; 21:E5498. [PMID: 32752093 PMCID: PMC7432025 DOI: 10.3390/ijms21155498] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023] Open
Abstract
Acinetobacter baumannii is considered one of the most persistent pathogens responsible for nosocomial infections. Due to the emergence of multidrug resistant strains, as well as high morbidity and mortality caused by this pathogen, A. baumannii was placed on the World Health Organization (WHO) drug-resistant bacteria and antimicrobial resistance research priority list. This review summarizes current studies on mechanisms that protect A. baumannii against multiple stresses caused by the host immune response, outside host environment, and antibiotic treatment. We particularly focus on the ability of A. baumannii to survive long-term desiccation on abiotic surfaces and the population heterogeneity in A. baumannii biofilms. Insight into these protective mechanisms may provide clues for the development of new strategies to fight multidrug resistant strains of A. baumannii.
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Affiliation(s)
- Soroosh Monem
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Beata Furmanek-Blaszk
- Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland;
| | - Adrianna Łupkowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Dorota Kuczyńska-Wiśnik
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Karolina Stojowska-Swędrzyńska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
| | - Ewa Laskowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (S.M.); (A.Ł.); (D.K.-W.); (K.S.-S.)
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