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Zuniga K, Thompson M, Muire PJ, Clay N, Karna SLR, Leatherman L, Lopez R, You T, Harm K, Brammer J, Wenke J, Christy R, Kowalczewski C. Development and Characterization of a Collagen-Based Three-Dimensional In Vitro Model to Mimic Biofilm Formation in a Wound Bed. ACS APPLIED BIO MATERIALS 2025. [PMID: 40433975 DOI: 10.1021/acsabm.5c00100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2025]
Abstract
Current studies using in vitro biofilm culturing systems have been instrumental at elucidating wound biofilm formation but fail to account for the diverse environment that bacteria are exposed to within the host. In the current study, we recapitulated this wound biofilm microenvironment by creating a hydrogel composed of collagen, thrombin, fibrinogen, meat broth, and FBS and subsequently infected the scaffolds with UAMS-1. We characterized the material properties of the hydrogel (noninfected) and found no significant differences in the storage modulus when fibrin was added to the collagen hydrogel. When infected with UAMS-1, temporal growth and polysaccharide formation were observed through plating, SEM, and histological staining, indicative of biofilm formation. PCR analysis revealed heightened expression of adhesion-associated genes with no increase in expression of metabolic genes, indicating significant increase in the formation of a robust biofilm over time. Vancomycin was ineffective in eradicating the already-developed biofilm, whereas the total CFUs in rifampin-treated models decreased significantly compared to those in the untreated group. Although it was not significant, an increase in SCVs was observed in the rifampin-treated group, suggesting that rifampin may create a harsher environment against the Staphylococcus aureus, allowing the increase in more resistant bacteria. The persistence of an infection in our rifampin-treated 3D in vitro wound model indicates an increased similarity to the host environment compared to that of a static biofilm model.
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Affiliation(s)
- Kameel Zuniga
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Marc Thompson
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Preeti J Muire
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Nicholas Clay
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - S L Rajasekhar Karna
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Logan Leatherman
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Rebecca Lopez
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Tao You
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Krystle Harm
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Jerod Brammer
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Joseph Wenke
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Robert Christy
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
| | - Christine Kowalczewski
- Combat Wound Care, U.S. Army Institute of Surgical Research, JBSA, Ft. Sam Houston, Texas 78234-7767, United States
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De S, Hakansson AP. Measuring Niche-Associated Metabolic Activity in Planktonic and Biofilm Bacteria. Methods Mol Biol 2023; 2674:3-32. [PMID: 37258957 DOI: 10.1007/978-1-0716-3243-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Most pathobionts of the respiratory tract form biofilms during asymptomatic colonization to survive and persist in this niche. Environmental changes of the host niche, often resulting from infection with respiratory viruses, changes of the microbiota composition, or other host assaults, can result in biofilm dispersion and spread of bacteria to other host niches, resulting in infections, such as otitis media, pneumonia, sepsis, and meningitis. The niches that these bacteria encounter during colonization and infection vary markedly in nutritional availability and contain different carbon sources and levels of other essential nutrients needed for bacterial growth and survival. As these niche-related nutritional variations regulate bacterial behavior and phenotype, a better understanding of bacterial niche-associated metabolic activity is likely to provide a broader understanding of bacterial pathogenesis. In this chapter, we use Streptococcus pneumoniae as a model respiratory pathobiont. We describe methods and models used to grow bacteria planktonically or to form biofilms in vitro by incorporating crucial host environmental factors, including the various carbon sources associated with specific niches, such as the nasopharynx or bloodstream. We then present methods describing how these models can be used to study bacterial phenotypes and their association with metabolic energy production and the generation of fermentation products.
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Affiliation(s)
- Supradipta De
- Department of Translational Medicine, Division of Experimental Infection Medicine, Wallenberg Laboratory, Lund University, Malmö, Sweden
| | - Anders P Hakansson
- Department of Translational Medicine, Division of Experimental Infection Medicine, Wallenberg Laboratory, Lund University, Malmö, Sweden.
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Rathore SS, Cheepurupalli L, Gangwar J, Raman T, Ramakrishnan J. Biofilm of Klebsiella pneumoniae minimize phagocytosis and cytokine expression by macrophage cell line. AMB Express 2022; 12:122. [PMID: 36121578 PMCID: PMC9485320 DOI: 10.1186/s13568-022-01465-z] [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: 06/07/2022] [Accepted: 09/10/2022] [Indexed: 12/05/2022] Open
Abstract
Infectious bacteria in biofilm mode are involved in many persistent infections. Owing to its importance in clinical settings, many in vitro and in vivo studies are being conducted to study the structural and functional properties of biofilms, their drug resistant mechanism and the s urvival mechanism of planktonic and biofilm cells. In this regard, there is not sufficient information on the interaction between Klebsiella biofilm and macrophages. In this study, we have attempted to unravel the interaction between Klebsiella biofilm and macrophages in terms of phagocytic response and cytokine expression. In vitro phagocytosis assays were performed for heat inactivated and live biofilms of K. pneumoniae, together with the expression analysis of TLR2, iNOS, inflammatory cytokines such as IL-β1, IFN-γ, IL-6, IL-12, IL-4, TNF-α and anti-inflammatory cytokine, IL-10. A phagocytic rate of an average of 15% was observed against both heat inactivated and live biofilms when LPS + IFN-γ activated macrophages were used. This was significantly higher than non-activated macrophages when tested against heat inactivated and live biofilms (average 8%). Heat-inactivated and live biofilms induced similar phagocytic responses and up-regulation of pro-inflammatory genes in macrophages, indirectly conveying that macrophage responses are to some extent dependent on the biofilm matrix.
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Affiliation(s)
- Sudarshan Singh Rathore
- Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology (SCBT), SASTRA Deemed University, Tamil Nadu, Tirumalaisamudram, Thanjavur, 613401, India
| | - Lalitha Cheepurupalli
- Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology (SCBT), SASTRA Deemed University, Tamil Nadu, Tirumalaisamudram, Thanjavur, 613401, India
| | - Jaya Gangwar
- Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology (SCBT), SASTRA Deemed University, Tamil Nadu, Tirumalaisamudram, Thanjavur, 613401, India
| | - Thiagarajan Raman
- Department of Advanced Zoology and Biotechnology, Ramakrishna Mission Vivekananda College, Mylapore, Chennai, 600004, India.
| | - Jayapradha Ramakrishnan
- Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology (SCBT), SASTRA Deemed University, Tamil Nadu, Tirumalaisamudram, Thanjavur, 613401, India.
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Krol A, Kokotkiewicz A, Luczkiewicz M. White Sage (Salvia apiana)-a Ritual and Medicinal Plant of the Chaparral: Plant Characteristics in Comparison with Other Salvia Species. PLANTA MEDICA 2022; 88:604-627. [PMID: 33890254 DOI: 10.1055/a-1453-0964] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Salvia apiana, commonly known as white sage, is an aromatic evergreen subshrub of the chaparral, commonly found in coastal plains in California and Baja California. It has been traditionally used by the Chumash people as a ritual and medicinal plant and used as a calmative, a diuretic, and a remedy for the common cold. However, until recently, relatively little has been known about the composition and biological activity of white sage. Phytochemical studies on S. apiana revealed the presence of substantial amounts of essential oil, accompanied by a variety of triterpenes, C23 terpenoids, diterpenes, and flavonoids. Extracts of the plant have been shown to exhibit antioxidative, antimicrobial, and cytotoxic effects. The influence of white sage constituents on the nervous system, including GABA, opioid, and cannabinoid receptors, has also been documented. The review aimed to compile information on the taxonomy, botany, chemical composition, and biological activities of S. apiana. White sage was compared with other representatives of the genus in terms of chemical composition. The differences and similarities between S. apiana and other sage species were noted and discussed in the context of their therapeutic applications. Reports on ethnomedicinal uses of white sage were confronted with reports on chemistry, bioactivity, and bioavailability of S. apiana constituents. Finally, a critical assessment of the available data was made and perspectives for the use of white sage preparations in modern phytomedicine were discussed.
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Affiliation(s)
- Agata Krol
- Department of Pharmacognosy, Faculty of Pharmacy, Medical University of Gdańsk, Gdańsk, Poland
| | - Adam Kokotkiewicz
- Department of Pharmacognosy, Faculty of Pharmacy, Medical University of Gdańsk, Gdańsk, Poland
| | - Maria Luczkiewicz
- Department of Pharmacognosy, Faculty of Pharmacy, Medical University of Gdańsk, Gdańsk, Poland
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Mirzaei R, Ranjbar R. Hijacking host components for bacterial biofilm formation: An advanced mechanism. Int Immunopharmacol 2022; 103:108471. [PMID: 34952466 DOI: 10.1016/j.intimp.2021.108471] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022]
Abstract
Biofilm is a community of bacteria embedded in the extracellular matrix that accounts for 80% of bacterial infections. Biofilm enables bacterial cells to provide particular conditions and produce virulence determinants in response to the unavailability of micronutrients and local oxygen, resulting in their resistance to various antibacterial agents. Besides, the human immune reactions are not completely competent in the elimination of biofilm. Most importantly, the growing body of evidence shows that some bacterial spp. use a variety of mechanisms by which hijack the host components to form biofilm. In this regard, host components, such as DNA, hyaluronan, collagen, fibronectin, mucin, oligosaccharide moieties, filamentous polymers (F-actin), plasma, platelets, keratin, sialic acid, laminin, vitronectin, C3- and C4- binding proteins, antibody, proteases, factor I, factor H, and acidic proline-rich proteins have been reviewed. Hence, the characterization of interactions between bacterial biofilm and the host would be critical to effectively address biofilm-associated infections. In this paper, we review the latest information on the hijacking of host factors by bacteria to form biofilm.
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Affiliation(s)
- Rasoul Mirzaei
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Reza Ranjbar
- Molecular Biology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran.
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6
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Mirzaei R, Sabokroo N, Ahmadyousefi Y, Motamedi H, Karampoor S. Immunometabolism in biofilm infection: lessons from cancer. Mol Med 2022; 28:10. [PMID: 35093033 PMCID: PMC8800364 DOI: 10.1186/s10020-022-00435-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 01/10/2022] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Biofilm is a community of bacteria embedded in an extracellular matrix, which can colonize different human cells and tissues and subvert the host immune reactions by preventing immune detection and polarizing the immune reactions towards an anti-inflammatory state, promoting the persistence of biofilm-embedded bacteria in the host. MAIN BODY OF THE MANUSCRIPT It is now well established that the function of immune cells is ultimately mediated by cellular metabolism. The immune cells are stimulated to regulate their immune functions upon sensing danger signals. Recent studies have determined that immune cells often display distinct metabolic alterations that impair their immune responses when triggered. Such metabolic reprogramming and its physiological implications are well established in cancer situations. In bacterial infections, immuno-metabolic evaluations have primarily focused on macrophages and neutrophils in the planktonic growth mode. CONCLUSION Based on differences in inflammatory reactions of macrophages and neutrophils in planktonic- versus biofilm-associated bacterial infections, studies must also consider the metabolic functions of immune cells against biofilm infections. The profound characterization of the metabolic and immune cell reactions could offer exciting novel targets for antibiofilm therapy.
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Affiliation(s)
- Rasoul Mirzaei
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
- Venom and Biotherapeutics Molecules Lab, Medical Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
| | - Niloofar Sabokroo
- Department of Microbiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Yaghoub Ahmadyousefi
- Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Hamadan University of Medical Sciences, Hamadan, Iran
- Research Center for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hamid Motamedi
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Sajad Karampoor
- Gastrointestinal and Liver Diseases Research Center, Iran University of Medical Sciences, Tehran, Iran.
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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Selvaraj C, Selvaraj G, Mohamed Ismail R, Vijayakumar R, Baazeem A, Wei DQ, Singh SK. Interrogation of Bacillus anthracis SrtA active site loop forming open/close lid conformations through extensive MD simulations for understanding binding selectivity of SrtA inhibitors. Saudi J Biol Sci 2021; 28:3650-3659. [PMID: 34220215 PMCID: PMC8241892 DOI: 10.1016/j.sjbs.2021.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 04/25/2021] [Accepted: 05/02/2021] [Indexed: 02/07/2023] Open
Abstract
Bacillus anthracis is a gram positive, deadly spore forming bacteria causing anthrax and these bacteria having the complex mechanism in the cell wall envelope, which can adopt the changes in environmental conditions. In this, the membrane bound cell wall proteins are said to progressive drug target for the inhibition of Bacillus anthracis. Among the cell wall proteins, the SrtA is one of the important mechanistic protein, which mediate the ligation with LPXTG motif by forming the amide bonds. The SrtA plays the vital role in cell signalling, cell wall formation, and biofilm formations. Inhibition of SrtA leads to rupture of the cell wall and biofilm formation, and that leads to inhibition of Bacillus anthracis and thus, SrtA is core important enzyme to study the inhibition mechanism. In this study, we have examined 28 compounds, which have the inhibitory activity against the Bacillus anthracis SrtA for developing the 3D-QSAR and also, compounds binding selectivity with both open and closed SrtA conformations, obtained from 100 ns of MD simulations. The binding site loop deviate in forming the open and closed gate mechanism is investigated to understand the inhibitory profile of reported compounds, and results show the closed state active site conformations are required for ligand binding specificity. Overall, the present study may offer an opportunity for better understanding of the mechanism of action and can be aided to further designing of a novel and highly potent SrtA inhibitors.
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Affiliation(s)
- Chandrabose Selvaraj
- Department of Bioinformatics, Computer Aided Drug Design and Molecular Modelling Lab, Science Block, Alagappa University, Karaikudi, Tamil Nadu, India
| | - Gurudeeban Selvaraj
- Centre for Research in Molecular Modelling, Concordia University, 5618 Montreal, Quebec, Canada
| | - Randa Mohamed Ismail
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia
- Department of Microbiology and Immunology, Veterinary Research Division, National Research Center (NRC), Giza, Egypt
| | - Rajendran Vijayakumar
- Department of Biology, College of Science in Zulfi, Majmaah University, Majmaah 11952, Saudi Arabia
| | - Alaa Baazeem
- Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Dong-Qing Wei
- Department of Bioinformatics and Biological Statistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Sanjeev Kumar Singh
- Department of Bioinformatics, Computer Aided Drug Design and Molecular Modelling Lab, Science Block, Alagappa University, Karaikudi, Tamil Nadu, India
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Lebov JF, Bohannan BJM. Msh Pilus Mutations Increase the Ability of a Free-Living Bacterium to Colonize a Piscine Host. Genes (Basel) 2021; 12:genes12020127. [PMID: 33498301 PMCID: PMC7909257 DOI: 10.3390/genes12020127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/12/2021] [Accepted: 01/18/2021] [Indexed: 02/07/2023] Open
Abstract
Symbioses between animals and bacteria are ubiquitous. To better understand these relationships, it is essential to unravel how bacteria evolve to colonize hosts. Previously, we serially passaged the free-living bacterium, Shewanella oneidensis, through the digestive tracts of germ-free larval zebrafish (Danio rerio) to uncover the evolutionary changes involved in the initiation of a novel symbiosis with a vertebrate host. After 20 passages, we discovered an adaptive missense mutation in the mshL gene of the msh pilus operon, which improved host colonization, increased swimming motility, and reduced surface adhesion. In the present study, we determined that this mutation was a loss-of-function mutation and found that it improved zebrafish colonization by augmenting S. oneidensis representation in the water column outside larvae through a reduced association with environmental surfaces. Additionally, we found that strains containing the mshL mutation were able to immigrate into host digestive tracts at higher rates per capita. However, mutant and evolved strains exhibited no evidence of a competitive advantage after colonizing hosts. Our results demonstrate that bacterial behaviors outside the host can play a dominant role in facilitating the onset of novel host associations.
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Affiliation(s)
- Jarrett F. Lebov
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403-5289, USA;
- Correspondence:
| | - Brendan J. M. Bohannan
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403-5289, USA;
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9
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Mukherjee G, Mukhopadhyay B, Sil AK. Edible marine algae: a new source for anti-mycobacterial agents. Folia Microbiol (Praha) 2020; 66:99-105. [PMID: 32975727 DOI: 10.1007/s12223-020-00823-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 09/15/2020] [Indexed: 10/23/2022]
Abstract
Tuberculosis is a dreaded disease, which causes innumerable death worldwide. The emergence of drug resistance strains makes the situation devastating. Therefore, for better management of public health, it is mandatory to search for new anti-mycobacterial agents. In this context, the current study investigated two edible marine algae, Ulva lactuca and Ulva intestinalis, for the probable source of new anti-mycobacterial agents. To test the anti-mycobacterial activity, alcoholic extracts of these two algae were spotted on the Mycobacterium smegmatis lawn. Upon incubation, clear zone was observed at the spots. It indicated that these two extracts have anti-mycobacterial activity. In addition, their anti-biofilm property was also tested. It was found that both the extracts inhibit the mycobacterial biofilm development as well as they can disperse the preformed mycobacterial biofilm. Since these two are capable of dispersing preformed mycobacterial biofilm, it is possible that in the presence of either of these two extracts, isoniazid and rifampicin can kill biofilm encapsulated mycobacterium in combinatorial therapy. Consistent with the hypothesis, rifampicin and isoniazid killed mycobacteria that were present in biofilm. Thus, these two extracts augment the activity of rifampicin and isoniazid upon biofilm dispersal. Moreover, treatment of different cell lines with these two extracts exhibited no or little cytotoxic effects. Thus, these two agents have the potential to be good therapeutic agents against mycobacterial diseases.
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Affiliation(s)
- Goutam Mukherjee
- Department of Microbiology, University of Calcutta, Kolkata, West Bengal, India
| | - Balaram Mukhopadhyay
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
| | - Alok Kumar Sil
- Department of Microbiology, University of Calcutta, Kolkata, West Bengal, India.
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10
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Phenotypic Parallelism during Experimental Adaptation of a Free-Living Bacterium to the Zebrafish Gut. mBio 2020; 11:mBio.01519-20. [PMID: 32817106 PMCID: PMC7439477 DOI: 10.1128/mbio.01519-20] [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] [Indexed: 12/20/2022] Open
Abstract
Although animals encounter many bacterial species throughout their lives, only a subset colonize vertebrate digestive tracts, and these bacteria can profoundly influence the health and development of their animal hosts. We used experimental evolution to study a free-living bacterium as it adapts to a novel vertebrate host by serially passaging replicate populations of Shewanella oneidensis through the intestines of larval zebrafish (Danio rerio). Our results demonstrate that adaptation to the zebrafish gut is complex, with multiple evolutionary pathways capable of improving colonization, but that motility plays an important role during the onset of host association. Although animals encounter a plethora of bacterial species throughout their lives, only a subset colonize vertebrate digestive tracts, and these bacteria can profoundly influence the health and development of their animal hosts. However, our understanding of how bacteria initiate symbioses with animal hosts remains underexplored, and this process is central to the assembly and function of gut bacterial communities. Therefore, we used experimental evolution to study a free-living bacterium as it adapts to a novel vertebrate host by serially passaging replicate populations of Shewanella oneidensis through the intestines of larval zebrafish (Danio rerio). After approximately 200 bacterial generations, isolates from evolved populations improved their ability to colonize larval zebrafish during competition against their unpassaged ancestor. Genome sequencing revealed unique sets of mutations in the two evolved isolates exhibiting the highest mean competitive fitness. One isolate exhibited increased swimming motility and decreased biofilm formation compared to the ancestor, and we identified a missense mutation in the mannose-sensitive hemagglutinin pilus operon that is sufficient to increase fitness and reproduce these phenotypes. The second isolate exhibited enhanced swimming motility but unchanged biofilm formation, and here the genetic basis for adaptation is less clear. These parallel enhancements in motility and fitness resemble the behavior of a closely related Shewanella strain previously isolated from larval zebrafish and suggest phenotypic convergence with this isolate. Our results demonstrate that adaptation to the zebrafish gut is complex, with multiple evolutionary pathways capable of improving colonization, but that motility plays an important role during the onset of host association.
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11
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Hakansson AP, Orihuela CJ, Bogaert D. Bacterial-Host Interactions: Physiology and Pathophysiology of Respiratory Infection. Physiol Rev 2018; 98:781-811. [PMID: 29488821 PMCID: PMC5966719 DOI: 10.1152/physrev.00040.2016] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 09/08/2017] [Accepted: 09/11/2017] [Indexed: 02/06/2023] Open
Abstract
It has long been thought that respiratory infections are the direct result of acquisition of pathogenic viruses or bacteria, followed by their overgrowth, dissemination, and in some instances tissue invasion. In the last decades, it has become apparent that in contrast to this classical view, the majority of microorganisms associated with respiratory infections and inflammation are actually common members of the respiratory ecosystem and only in rare circumstances do they cause disease. This suggests that a complex interplay between host, environment, and properties of colonizing microorganisms together determines disease development and its severity. To understand the pathophysiological processes that underlie respiratory infectious diseases, it is therefore necessary to understand the host-bacterial interactions occurring at mucosal surfaces, along with the microbes inhabiting them, during symbiosis. Current knowledge regarding host-bacterial interactions during asymptomatic colonization will be discussed, including a plausible role for the human microbiome in maintaining a healthy state. With this as a starting point, we will discuss possible disruptive factors contributing to dysbiosis, which is likely to be a key trigger for pathobionts in the development and pathophysiology of respiratory diseases. Finally, from this renewed perspective, we will reflect on current and potential new approaches for treatment in the future.
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Affiliation(s)
- A P Hakansson
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University , Lund , Sweden ; Department of Microbiology, University of Alabama at Birmingham , Birmingham, Alabama ; and Center for Inflammation Research, Queens Medical Research Institute, University of Edinburgh , Edinburgh , United Kingdom
| | - C J Orihuela
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University , Lund , Sweden ; Department of Microbiology, University of Alabama at Birmingham , Birmingham, Alabama ; and Center for Inflammation Research, Queens Medical Research Institute, University of Edinburgh , Edinburgh , United Kingdom
| | - D Bogaert
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University , Lund , Sweden ; Department of Microbiology, University of Alabama at Birmingham , Birmingham, Alabama ; and Center for Inflammation Research, Queens Medical Research Institute, University of Edinburgh , Edinburgh , United Kingdom
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12
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Adenoid bacterial colonization in a paediatric population. Eur Arch Otorhinolaryngol 2017; 274:1933-1938. [PMID: 28213779 DOI: 10.1007/s00405-017-4493-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 02/02/2017] [Indexed: 12/17/2022]
Abstract
Adenoids play a key role in both respiratory and ear infection in children. It has also been shown that adenoidectomy improves these symptoms in this population. The main goal of the present study was to evaluate adenoid bacterial colonization and document a possible relation with infectious respiratory disease. A prospective observational study was designed to evaluate the proposed hypothesis in a paediatric population submitted to adenoidectomy by either infectious or non-infectious indications and compare these two cohorts. A total of 62 patients with ages ranging from 1 to 12 years old were enrolled in the study. Adenoid surface, adenoid core and middle meatus microbiota were compared. A close association between adenoid colonization and nasal infection was found, supporting that adenoids may function as bacterial reservoir for upper airway infection. The obtained results also contribute to explain the success of adenoidectomy in patients with infectious indications.
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13
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Pandin C, Le Coq D, Canette A, Aymerich S, Briandet R. Should the biofilm mode of life be taken into consideration for microbial biocontrol agents? Microb Biotechnol 2017; 10:719-734. [PMID: 28205337 PMCID: PMC5481536 DOI: 10.1111/1751-7915.12693] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 01/19/2017] [Accepted: 01/20/2017] [Indexed: 11/26/2022] Open
Abstract
Almost one‐third of crop yields are lost every year due to microbial alterations and diseases. The main control strategy to limit these losses is the use of an array of chemicals active against spoilage and unwanted pathogenic microorganisms. Their massive use has led to extensive environmental pollution, human poisoning and a variety of diseases. An emerging alternative to this chemical approach is the use of microbial biocontrol agents. Biopesticides have been used with success in several fields, but a better understanding of their mode of action is necessary to better control their activity and increase their use. Very few studies have considered that biofilms are the preferred mode of life of microorganisms in the target agricultural biotopes. Increasing evidence shows that the spatial organization of microbial communities on crop surfaces may drive important bioprotection mechanisms. The aim of this review is to summarize the evidence of biofilm formation by biocontrol agents on crops and discuss how this surface‐associated mode of life may influence their biology and interactions with other microorganisms and the host and, finally, their overall beneficial activity.
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Affiliation(s)
- Caroline Pandin
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Dominique Le Coq
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.,Micalis Institute, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Alexis Canette
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Stéphane Aymerich
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Romain Briandet
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
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Walker RE, Bartley J, Flint D, Thompson JMD, Mitchell EA. Determinants of chronic otitis media with effusion in preschool children: a case-control study. BMC Pediatr 2017; 17:4. [PMID: 28056905 PMCID: PMC5217332 DOI: 10.1186/s12887-016-0767-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 12/21/2016] [Indexed: 02/17/2023] Open
Abstract
Background Chronic otitis media with effusion (COME) is a prevalent upper airway infection resulting in hearing loss. The aim of this research was to determine risk factors for COME in preschool children. Methods A case–control design was conducted in Auckland, New Zealand from May 2011 until November 2013. The cases were children aged 3 and 4 years referred for tympanostomy tube placement due to a diagnosis of COME (n = 178). The controls were a random sample of healthy children aged 3 and 4 years from primary care practices (n = 209). The children’s guardians completed an interviewer-administered questionnaire that covered topics including socio-demographic information, pregnancy and birth, infant feeding practices, home environment, and respiratory health. In addition, skin prick tests for atopy were performed. Odds ratios (OR) estimating the risk of COME independently associated with the exposures were calculated using a logistic regression model. Results Children with COME frequently had nasal obstruction (OR: 4.38 [95% CI: 2.37–8.28]), always snored (OR: 3.64 [95% CI: 1.51–9.15]) or often snored (OR: 2.45 [95% CI: 1.04–5.96]), spent more hours per week in daycare (OR per hour/week: 1.03 [95% CI: 1.00–1.05]), had frequent colds (OR: 2.67 [95% CI: 1.59–4.53]), had siblings who had undergone tympanostomy tube placement (OR: 2.68 [95% CI: 1.22–6.02]), underwent long labour (OR: 2.59 [95% CI: 1.03–6.79]), and had early introduction of cow’s milk (OR: 1.76 [95% CI: 1.05–2.97]). Asian ethnicity (OR: 0.20 [95% CI: 0.07–0.53]) and having older siblings (OR: 0.54 [95% CI: 0.31–0.93]) were inversely associated with COME. Conclusion COME in preschool children was associated with pathogen exposure, respiratory infection, and nasal obstruction. Strategies to prevent pathogen transmission warrant investigation. The novel findings of long labour and early cow’s milk introduction require replication in future studies.
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Affiliation(s)
- Rebecca E Walker
- Department of Paediatrics: Child and Youth Health, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
| | - Jim Bartley
- Division of Otolaryngology-Head and Neck Surgery, Counties-Manukau District Health Board, Manukau SuperClinic™, PO Box 98743, Manukau City, Auckland, 2241, New Zealand
| | - David Flint
- Division of Otolaryngology-Head and Neck Surgery, Counties-Manukau District Health Board, Manukau SuperClinic™, PO Box 98743, Manukau City, Auckland, 2241, New Zealand
| | - John M D Thompson
- Department of Paediatrics: Child and Youth Health, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Edwin A Mitchell
- Department of Paediatrics: Child and Youth Health, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
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15
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Abstract
Streptococcus pneumoniae is an opportunistic pathogen globally associated with significant morbidity and mortality. It is capable of causing a wide range of diseases including sinusitis, conjunctivitis, otitis media, pneumonia, bacteraemia, sepsis, and meningitis. While its capsular polysaccharide is indispensible for invasive disease, and opsonising antibodies against the capsule are the basis for the current vaccines, a long history of biomedical research indicates that other components of this Gram-positive bacterium are also critical for virulence. Herein we review the contribution of pneumococcal virulence determinants to survival and persistence in the context of distinct anatomical sites. We discuss how these determinants allow the pneumococcus to evade mucociliary clearance during colonisation, establish lower respiratory tract infection, resist complement deposition and opsonophagocytosis in the bloodstream, and invade secondary tissues such as the central nervous system leading to meningitis. We do so in a manner that highlights both the critical role of the capsular polysaccharide and the accompanying and necessary protein determinants. Understanding the complex interplay between host and pathogen is necessary to find new ways to prevent pneumococcal infection. This review is an attempt to do so with consideration for the latest research findings.
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16
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Domenech M, Ruiz S, Moscoso M, García E. In vitro biofilm development of Streptococcus pneumoniae and formation of choline-binding protein-DNA complexes. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:715-727. [PMID: 25950767 DOI: 10.1111/1758-2229.12295] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 04/08/2015] [Indexed: 06/04/2023]
Abstract
Extracellular deoxyribonucleic acid (eDNA) is an essential component of bacterial biofilm matrices, and is required in their formation and maintenance. Extracellular DNA binds to exopolysaccharides or extracellular proteins, affording biofilms greater structural integrity. Recently, we reported evidence of intercellular eDNA-LytC complexes in pneumococcal biofilms. The LytC lysozyme is a member of the choline-binding family of proteins (CBPs) located on the pneumococcal surface. The present work shows that other CBPs, i.e. LytA, LytB, Pce, PspC and CbpF, which have a pI between 5 and 6, can bind DNA in vitro. This process requires the presence of divalent cations other than Mg(2+). This DNA binding capacity of CBPs appears to be independent of their enzymatic activity and, at least in the case of LytA, does not require the choline-binding domain characteristic of CBPs. Positively charged, surface-exposed, 25 amino acid-long peptides derived from the catalytic domain of LytB, were also found capable of DNA binding through electrostatic interactions. Confocal laser scanning microcopy revealed the existence of cell-associated LytB-eDNA complexes in Streptococcus pneumoniae biofilms. These and other findings suggest that these surface-located proteins of S. pneumoniae could play roles of varying importance in the colonization and/or invasion of human host where different environmental conditions exist.
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Affiliation(s)
- Mirian Domenech
- Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, 28040, Spain
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Susana Ruiz
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Miriam Moscoso
- Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, 28040, Spain
| | - Ernesto García
- Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, 28040, Spain
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
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17
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Rana A, Ahmed M, Rub A, Akhter Y. A tug-of-war between the host and the pathogen generates strategic hotspots for the development of novel therapeutic interventions against infectious diseases. Virulence 2015; 6:566-80. [PMID: 26107578 PMCID: PMC4720223 DOI: 10.1080/21505594.2015.1062211] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 06/02/2015] [Accepted: 06/10/2015] [Indexed: 12/30/2022] Open
Abstract
Microbial pathogens are known to express an array of specific signaling molecules referred as Pathogen Associated Molecular Patterns (PAMPs), which are recognized by Pattern Recognition Receptors (PRRs), present on the surface of the host cells. Interactions between PAMPs and PRRs on the surface of the host cells lead to signaling events which could culminate into either successful infection or clearance of the pathogens. Here, we summarize how these events may generate novel host based as well as pathogen based molecular targets for designing effective therapeutic strategies against infections.
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Affiliation(s)
- Aarti Rana
- School of Life Sciences; Central University of Himachal Pradesh; Shahpur, District-Kangra, Himachal Pradesh, India
| | - Mushtaq Ahmed
- School of Earth and Environmental Sciences; Central University of Himachal Pradesh; Shahpur, District-Kangra, Himachal Pradesh, India
| | - Abdur Rub
- Infection and Immunity Lab; Department of Biotechnology; Jamia Millia Islamia (A Central University); New Delhi, India
| | - Yusuf Akhter
- School of Life Sciences; Central University of Himachal Pradesh; Shahpur, District-Kangra, Himachal Pradesh, India
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18
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Gilley RP, Orihuela CJ. Pneumococci in biofilms are non-invasive: implications on nasopharyngeal colonization. Front Cell Infect Microbiol 2014; 4:163. [PMID: 25414838 PMCID: PMC4222220 DOI: 10.3389/fcimb.2014.00163] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 10/21/2014] [Indexed: 11/21/2022] Open
Abstract
Streptococcus pneumoniae (the pneumococcus) is an opportunistic pathogen that colonizes the human nasopharynx asymptomatically. Invasive pneumococcal disease develops following bacterial aspiration into the lungs. Pneumococci within the nasopharynx exist as biofilms, a growth phenotype characterized by surface attachment, encasement within an extracellular matrix, and antimicrobial resistance. Experimental evidence indicates that biofilm pneumococci are attenuated vs. their planktonic counterpart. Biofilm pneumococci failed to cause invasive disease in experimentally challenged mice and in vitro were shown to be non-invasive despite being hyper-adhesive. This attenuated phenotype corresponds with observations that biofilm pneumococci elicit significantly less cytokine and chemokine production from host cells than their planktonic counterparts. Microarray and proteomic studies show that pneumococci within biofilms have decreased metabolism, less capsular polysaccharide, and reduced production of the pore-forming toxin pneumolysin. Biofilm pneumococci are predominately in the transparent phenotype, which has elevated cell wall phosphorylcholine, an adhesin subject to C-reactive protein mediated opsonization. Herein, we review these changes in virulence, interpret their impact on colonization and transmission, and discuss the notion that non-invasive biofilms are principal lifestyle of S. pneumoniae.
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Affiliation(s)
- Ryan P Gilley
- Department of Microbiology and Immunology, Center for Airway Inflammation Research, The University of Texas Health Science Center at San Antonio San Antonio, TX, USA
| | - Carlos J Orihuela
- Department of Microbiology and Immunology, Center for Airway Inflammation Research, The University of Texas Health Science Center at San Antonio San Antonio, TX, USA
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19
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Cardile AP, Sanchez CJ, Samberg ME, Romano DR, Hardy SK, Wenke JC, Murray CK, Akers KS. Human plasma enhances the expression of Staphylococcal microbial surface components recognizing adhesive matrix molecules promoting biofilm formation and increases antimicrobial tolerance In Vitro. BMC Res Notes 2014; 7:457. [PMID: 25034276 PMCID: PMC4110374 DOI: 10.1186/1756-0500-7-457] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/30/2014] [Indexed: 12/24/2022] Open
Abstract
Background Microbial biofilms have been associated with the development of chronic human infections and represent a clinical challenge given their increased antimicrobial tolerance. Staphylococcus aureus is a major human pathogen causing a diverse range of diseases, of which biofilms are often involved. Staphylococcal attachment and the formation of biofilms have been shown to be facilitated by host factors that accumulate on surfaces. To better understand how host factors enhance staphylococcal biofilm formation, we evaluated the effect of whole human plasma on biofilm formation in clinical isolates of S. aureus and the expression of seven microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) known to be involved in biofilm formation by quantitative real-time PCR. We also evaluated whether plasma augmented changes in S. aureus biofilm morphology and antimicrobial resistance. Results Exposure of clinical isolates of S. aureus to human plasma (10%) within media, and to a lesser extent when coated onto plates, significantly enhanced biofilm formation in all of the clinical isolates tested. Compared to biofilms grown under non-supplemented conditions, plasma-augmented biofilms displayed significant changes in both the biofilm phenotype and cell morphology as determined by confocal scanning laser microscopy (CLSM) and scanning electron microscopy (SEM), respectively. Exposure of bacteria to plasma resulted in a significant fold-increase in MSCRAMM expression in both a time and isolate-dependent manner. Additionally, plasma-augmented biofilms displayed an increased tolerance to vancomycin compared to biofilms grown in non-supplemented media. Conclusions Collectively, these studies support previous findings demonstrating a role for host factors in biofilm formation and provide further insight into how plasma, a preferred growth medium for staphylococcal biofilm formation enhances as well as augments other intrinsic properties of S. aureus biofilms. Consequently, these findings indicate that incorporation of host factors may be necessary to better replicate in vivo conditions and for the best utility of a clinical biofilm assay to evaluate the process of biofilm formation and treatments.
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Affiliation(s)
- Anthony P Cardile
- Department of Medicine, Infectious Disease Service, Brooke Army Medical Center, 3551 Roger Brooke Drive, JBSA Fort Sam Houston, TX 78234, USA.
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