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Characterization of Distinct Biofilm Cell Subpopulations and Implications in Quorum Sensing and Antibiotic Resistance. mBio 2022; 13:e0019122. [PMID: 35695457 PMCID: PMC9239111 DOI: 10.1128/mbio.00191-22] [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: 11/29/2022] Open
Abstract
Bacteria change phenotypically in response to their environment. Free swimming cells transition to biofilm communities that promote cellular cooperativity and resistance to stressors and antibiotics. We uncovered three subpopulations of cells with diverse phenotypes from a single-species Pseudomonas aeruginosa PA14 biofilm, and used a series of steps to isolate, characterize, and map these cell subpopulations in a biofilm. The subpopulations were distinguishable by size and morphology using dynamic light scattering (DLS) and scanning electron microscopy (SEM). Additionally, growth and dispersal of biofilms originating from each cell subpopulation exhibited contrasting responses to antibiotic challenge. Cell subpopulation surface charges were distinctly different, which led us to examine the ionizable surface molecules associated with each subpopulation using mass spectrometry. Matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of cell subpopulations revealed ions unique to each subpopulation of cells that significantly co-localized with ions associated with quorum sensing. Transcript levels of algR, lasR, and rhlI in subpopulations isolated from biofilms differed from levels in planktonic stationary and mid-log cell subpopulations. These studies provide insight into diverse phenotypes, morphologies, and biochemistries of PA14 cell subpopulations for potential applications in combating bacterial pathogenesis, with medical, industrial, and environmental complications.
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Barceló IM, Torrens G, Escobar-Salom M, Jordana-Lluch E, Capó-Bauzá MM, Ramón-Pallín C, García-Cuaresma D, Fraile-Ribot PA, Mulet X, Oliver A, Juan C. Impact of Peptidoglycan Recycling Blockade and Expression of Horizontally Acquired β-Lactamases on Pseudomonas aeruginosa Virulence. Microbiol Spectr 2022; 10:e0201921. [PMID: 35171032 PMCID: PMC8849096 DOI: 10.1128/spectrum.02019-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/24/2022] [Indexed: 01/02/2023] Open
Abstract
In the current scenario of antibiotic resistance magnification, new weapons against top nosocomial pathogens like Pseudomonas aeruginosa are urgently needed. The interplay between β-lactam resistance and virulence is considered a promising source of targets to be attacked by antivirulence therapies, and in this regard, we previously showed that a peptidoglycan recycling blockade dramatically attenuated the pathogenic power of P. aeruginosa strains hyperproducing the chromosomal β-lactamase AmpC. Here, we sought to ascertain whether this observation could be applicable to other β-lactamases. To do so, P. aeruginosa wild-type or peptidoglycan recycling-defective strains (ΔampG and ΔnagZ) harboring different cloned β-lactamases (transferable GES, VIM, and OXA types) were used to assess their virulence in Galleria mellonella larvae by determining 50% lethal doses (LD50s). A mild yet significant LD50 increase was observed after peptidoglycan recycling disruption per se, whereas the expression of class A and B enzymes did not impact virulence. While the production of the narrow-spectrum class D OXA-2 entailed a slight attenuation, its extended-spectrum derivatives OXA-226 (W159R [bearing a change of W to R at position 159]), OXA-161 (N148D), and principally, OXA-539 (D149 duplication) were associated with outstanding virulence impairments, especially in recycling-defective backgrounds (with some LD50s being >1,000-fold that of the wild type). Although their exact molecular bases remain to be deciphered, these results suggest that mutations affecting the catalytic center and, therefore, the hydrolytic spectrum of OXA-2-derived enzymes also drastically impact the pathogenic power of P. aeruginosa. This work provides new and relevant knowledge to the complex topic of the interplay between the production of β-lactamases and virulence that could be useful to build future therapeutic strategies against P. aeruginosa. IMPORTANCE Pseudomonas aeruginosa is one of the leading nosocomial pathogens whose growing resistance makes the development of therapeutic options extremely urgent. The resistance-virulence interplay has classically aroused researchers' interest as a source of therapeutic targets. In this regard, we describe a wide array of virulence attenuations associated with different transferable β-lactamases, among which the production of OXA-2-derived extended-spectrum β-lactamases stood out as a dramatic handicap for pathogenesis, likely as a side effect of mutations causing the expansion of their hydrolytic spectrums. Moreover, our results confirm the validity of disturbing peptidoglycan recycling as a weapon to attenuate P. aeruginosa virulence in class C and D β-lactamase production backgrounds. In the current scenario of dissemination of horizontally acquired β-lactamases, this work brings out new data on the complex interplay between the production of specific enzymes and virulence attenuation that, if complemented with the characterization of the underlying mechanisms, will likely be exploitable to develop future virulence-targeting antipseudomonal strategies.
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Affiliation(s)
- Isabel M. Barceló
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- CIBER de Enfermedades Infecciosas, Madrid, Spain
| | - Gabriel Torrens
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- CIBER de Enfermedades Infecciosas, Madrid, Spain
| | - María Escobar-Salom
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- CIBER de Enfermedades Infecciosas, Madrid, Spain
| | - Elena Jordana-Lluch
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - María Magdalena Capó-Bauzá
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Carlos Ramón-Pallín
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Daniel García-Cuaresma
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Pablo A. Fraile-Ribot
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- CIBER de Enfermedades Infecciosas, Madrid, Spain
| | - Xavier Mulet
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- CIBER de Enfermedades Infecciosas, Madrid, Spain
| | - Antonio Oliver
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- CIBER de Enfermedades Infecciosas, Madrid, Spain
| | - Carlos Juan
- Microbiology Department and Research Unit, University Hospital Son Espases, Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- CIBER de Enfermedades Infecciosas, Madrid, Spain
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Escobar‐Salom M, Torrens G, Jordana‐Lluch E, Oliver A, Juan C. Mammals' humoral immune proteins and peptides targeting the bacterial envelope: from natural protection to therapeutic applications against multidrug‐resistant
Gram
‐negatives. Biol Rev Camb Philos Soc 2022; 97:1005-1037. [PMID: 35043558 PMCID: PMC9304279 DOI: 10.1111/brv.12830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 12/12/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022]
Abstract
Mammalian innate immunity employs several humoral ‘weapons’ that target the bacterial envelope. The threats posed by the multidrug‐resistant ‘ESKAPE’ Gram‐negative pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are forcing researchers to explore new therapeutic options, including the use of these immune elements. Here we review bacterial envelope‐targeting (peptidoglycan and/or membrane‐targeting) proteins/peptides of the mammalian immune system that are most likely to have therapeutic applications. Firstly we discuss their general features and protective activity against ESKAPE Gram‐negatives in the host. We then gather, integrate, and discuss recent research on experimental therapeutics harnessing their bactericidal power, based on their exogenous administration and also on the discovery of bacterial and/or host targets that improve the performance of this endogenous immunity, as a novel therapeutic concept. We identify weak points and knowledge gaps in current research in this field and suggest areas for future work to obtain successful envelope‐targeting therapeutic options to tackle the challenge of antimicrobial resistance.
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Affiliation(s)
- María Escobar‐Salom
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Gabriel Torrens
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Elena Jordana‐Lluch
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Antonio Oliver
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Carlos Juan
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
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Molecular Mechanisms Involved in Pseudomonas aeruginosa Bacteremia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:325-345. [DOI: 10.1007/978-3-031-08491-1_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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Ferraboschi P, Ciceri S, Grisenti P. Applications of Lysozyme, an Innate Immune Defense Factor, as an Alternative Antibiotic. Antibiotics (Basel) 2021; 10:1534. [PMID: 34943746 PMCID: PMC8698798 DOI: 10.3390/antibiotics10121534] [Citation(s) in RCA: 105] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/03/2021] [Accepted: 12/08/2021] [Indexed: 12/18/2022] Open
Abstract
Lysozyme is a ~14 kDa protein present in many mucosal secretions (tears, saliva, and mucus) and tissues of animals and plants, and plays an important role in the innate immunity, providing protection against bacteria, viruses, and fungi. Three main different types of lysozymes are known: the c-type (chicken or conventional type), the g-type (goose type), and the i-type (invertebrate type). It has long been the subject of several applications due to its antimicrobial properties. The problem of antibiotic resistance has stimulated the search for new molecules or new applications of known compounds. The use of lysozyme as an alternative antibiotic is the subject of this review, which covers the results published over the past two decades. This review is focused on the applications of lysozyme in medicine, (the treatment of infectious diseases, wound healing, and anti-biofilm), veterinary, feed, food preservation, and crop protection. It is available from a wide range of sources, in addition to the well-known chicken egg white, and its synergism with other compounds, endowed with antimicrobial activity, are also summarized. An overview of the modified lysozyme applications is provided in the form of tables.
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Affiliation(s)
- Patrizia Ferraboschi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Via C. Saldini 50, 20133 Milano, Italy;
| | - Samuele Ciceri
- Department of Pharmaceutical Sciences, University of Milan, Via L. Mangiagalli 25, 20133 Milano, Italy;
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Torrens G, Escobar-Salom M, Oliver A, Juan C. Activity of mammalian peptidoglycan-targeting immunity against Pseudomonas aeruginosa. J Med Microbiol 2020; 69:492-504. [PMID: 32427563 DOI: 10.1099/jmm.0.001167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pseudomonas aeruginosa is one of the most important opportunistic pathogens, whose clinical relevance is not only due to the high morbidity/mortality of the infections caused, but also to its striking capacity for antibiotic resistance development. In the current scenario of a shortage of effective antipseudomonal drugs, it is essential to have thorough knowledge of the pathogen's biology from all sides, so as to find weak points for drug development. Obviously, one of these points could be the peptidoglycan, given its essential role for cell viability. Meanwhile, immune weapons targeting this structure could constitute an excellent model to be taken advantage of in order to design new therapeutic strategies. In this context, this review gathers all the information regarding the activity of mammalian peptidoglycan-targeting innate immunity (namely lysozyme and peptidoglycan recognition proteins), specifically against P. aeruginosa. All the published studies were considered, from both in vitro and in vivo fields, including works that envisage these weapons as options not only to potentiate their innate effects within the host or for use as exogenously administered treatments, but also harnessing their inflammatory and immune regulatory capacity to finally reduce damage in the patient. Altogether, this review has the objective of anticipating and discussing whether these innate immune resources, in combination or not with other drugs attacking certain P. aeruginosa targets leading to its increased sensitization, could be valid therapeutic antipseudomonal allies.
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Affiliation(s)
- Gabriel Torrens
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Maria Escobar-Salom
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Antonio Oliver
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitari Son Espases-Institut de Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
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Torrens G, Sánchez-Diener I, Jordana-Lluch E, Barceló IM, Zamorano L, Juan C, Oliver A. In Vivo Validation of Peptidoglycan Recycling as a Target to Disable AmpC-Mediated Resistance and Reduce Virulence Enhancing the Cell-Wall-Targeting Immunity. J Infect Dis 2020; 220:1729-1737. [PMID: 31325363 DOI: 10.1093/infdis/jiz377] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/16/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Searching for new strategies to defeat Pseudomonas aeruginosa is of paramount importance. Previous works in vitro showed that peptidoglycan recycling blockade disables AmpC-dependent resistance and enhances susceptibility against cell-wall-targeting immunity. Our objective was to validate these findings in murine models.This study shows for the first time in different murine models of infection that blocking the peptidoglycan recycling in Pseudomonas aeruginosa causes an important virulence impairment and disables AmpC-mediated resistance, being hence validated as a promising therapeutic target. METHODS Wildtype PAO1, recycling-defective AmpG and NagZ mutants, an AmpC hyperproducer dacB mutant, and their combinations were used to cause systemic/respiratory infections in mice. Their survival, bacterial burden, inflammation level, and effectiveness of ceftazidime or subtherapeutic colistin to treat the infections were assessed. RESULTS Inactivation of AmpG or NagZ significantly attenuated the virulence in terms of mice mortality, bacterial load, and inflammation. When inactivating these genes in the dacB-defective background, the β-lactam resistance phenotype was abolished, disabling the emergence of ceftazidime-resistant mutants, and restoring ceftazidime for treatment. Subtherapeutic colistin was shown to efficiently clear the infection caused by the recycling-defective strains, likely due to the combined effect with the mice cell-wall- targeting immunity. CONCLUSIONS This study brings us one step closer to new therapies intended to disable P. aeruginosa AmpC-mediated resistance and dampen its virulence, and strongly support the interest in developing efficient AmpG and/or NagZ inhibitors.
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Affiliation(s)
- Gabriel Torrens
- Servicio de Microbiología and Unidad de Investigación, Hospital Son Espases, Instituto de Investigación Sanitaria de Baleares, Palma, Spain
| | - Irina Sánchez-Diener
- Servicio de Microbiología and Unidad de Investigación, Hospital Son Espases, Instituto de Investigación Sanitaria de Baleares, Palma, Spain
| | - Elena Jordana-Lluch
- Servicio de Microbiología and Unidad de Investigación, Hospital Son Espases, Instituto de Investigación Sanitaria de Baleares, Palma, Spain
| | - Isabel María Barceló
- Servicio de Microbiología and Unidad de Investigación, Hospital Son Espases, Instituto de Investigación Sanitaria de Baleares, Palma, Spain
| | - Laura Zamorano
- Servicio de Microbiología and Unidad de Investigación, Hospital Son Espases, Instituto de Investigación Sanitaria de Baleares, Palma, Spain
| | - Carlos Juan
- Servicio de Microbiología and Unidad de Investigación, Hospital Son Espases, Instituto de Investigación Sanitaria de Baleares, Palma, Spain
| | - Antonio Oliver
- Servicio de Microbiología and Unidad de Investigación, Hospital Son Espases, Instituto de Investigación Sanitaria de Baleares, Palma, Spain
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Torrens G, Escobar-Salom M, Pol-Pol E, Camps-Munar C, Cabot G, López-Causapé C, Rojo-Molinero E, Oliver A, Juan C. Comparative Analysis of Peptidoglycans From Pseudomonas aeruginosa Isolates Recovered From Chronic and Acute Infections. Front Microbiol 2019; 10:1868. [PMID: 31507543 PMCID: PMC6719521 DOI: 10.3389/fmicb.2019.01868] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 07/29/2019] [Indexed: 12/20/2022] Open
Abstract
Pseudomonas aeruginosa is one of the first causes of acute nosocomial and chronic infections in patients with underlying respiratory pathologies such as cystic fibrosis (CF). It has been proposed that P. aeruginosa accumulates mutations driving to peptidoglycan modifications throughout the development of the CF-associated infection, as a strategy to lower the immune detection hence ameliorating the chronic persistence. As well, some studies dealing with peptidoglycan modifications driving to a better survival within the host have been published in other gram-negatives. According to these facts, the gram-negative peptidoglycan could be considered as a pathogen-associated molecular pattern with very important implications regarding the host’s detection-response, worthy to dissect in detail. For this reason, in this work we characterized for the first time the peptidoglycans of three large collections [early CF, late CF and acute infection (bloodstream) P. aeruginosa strains] from qualitative (HPLC), quantitative and inflammatory capacity-related perspectives. The final goal was to identify composition trends potentially supporting the cited strategy of evasion/resistance to the immune system and providing information regarding the differential intrinsic adaptation depending on the type of infection. Although we found several punctual strain-specific particularities, our results indicated a high degree of inter-collection uniformity in the peptidoglycan-related features and the absence of trends amongst the strains studied here. These results suggest that the peptidoglycan of P. aeruginosa is a notably conserved structure in natural isolates regardless of transitory changes that some external conditions could force. Finally, the inverse correlation between the relative amount of stem pentapeptides within the murein sacculus and the resistance to immune lytic attacks against the peptidoglycan was also suggested by our results. Altogether, this work is a major step ahead to understand the biology of peptidoglycan from P. aeruginosa natural strains, hopefully useful in future for therapeutic alternatives design.
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Affiliation(s)
- Gabriel Torrens
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - María Escobar-Salom
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Elisabet Pol-Pol
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Cristina Camps-Munar
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Gabriel Cabot
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Carla López-Causapé
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Estrella Rojo-Molinero
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Antonio Oliver
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
| | - Carlos Juan
- Servicio de Microbiología-Unidad de Investigación, Hospital Universitari Son Espases-Institut d'Investigació Sanitària Illes Balears (IdISBa), Palma, Spain
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