1
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Biology and Regulation of Staphylococcal Biofilm. Int J Mol Sci 2023; 24:ijms24065218. [PMID: 36982293 PMCID: PMC10049468 DOI: 10.3390/ijms24065218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/15/2023] [Accepted: 03/03/2023] [Indexed: 03/11/2023] Open
Abstract
Despite continuing progress in medical and surgical procedures, staphylococci remain the major Gram-positive bacterial pathogens that cause a wide spectrum of diseases, especially in patients requiring the utilization of indwelling catheters and prosthetic devices implanted temporarily or for prolonged periods of time. Within the genus, if Staphylococcus aureus and S. epidermidis are prevalent species responsible for infections, several coagulase-negative species which are normal components of our microflora also constitute opportunistic pathogens that are able to infect patients. In such a clinical context, staphylococci producing biofilms show an increased resistance to antimicrobials and host immune defenses. Although the biochemical composition of the biofilm matrix has been extensively studied, the regulation of biofilm formation and the factors contributing to its stability and release are currently still being discovered. This review presents and discusses the composition and some regulation elements of biofilm development and describes its clinical importance. Finally, we summarize the numerous and various recent studies that address attempts to destroy an already-formed biofilm within the clinical context as a potential therapeutic strategy to avoid the removal of infected implant material, a critical event for patient convenience and health care costs.
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2
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Rohokale R, Guo Z. Development in the Concept of Bacterial Polysaccharide Repeating Unit-Based Antibacterial Conjugate Vaccines. ACS Infect Dis 2023; 9:178-212. [PMID: 36706246 PMCID: PMC9930202 DOI: 10.1021/acsinfecdis.2c00559] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The surface of cells is coated with a dense layer of glycans, known as the cell glycocalyx. The complex glycans in the glycocalyx are involved in various biological events, such as bacterial pathogenesis, protection of bacteria from environmental stresses, etc. Polysaccharides on the bacterial cell surface are highly conserved and accessible molecules, and thus they are excellent immunological targets. Consequently, bacterial polysaccharides and their repeating units have been extensively studied as antigens for the development of antibacterial vaccines. This Review surveys the recent developments in the synthetic and immunological investigations of bacterial polysaccharide repeating unit-based conjugate vaccines against several human pathogenic bacteria. The major challenges associated with the development of functional carbohydrate-based antibacterial conjugate vaccines are also considered.
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Dollery SJ, Harro JM, Wiggins TJ, Wille BP, Kim PC, Tobin JK, Bushnell RV, Tasker NJPER, MacLeod DA, Tobin GJ. Select Whole-Cell Biofilm-Based Immunogens Protect against a Virulent Staphylococcus Isolate in a Stringent Implant Model of Infection. Vaccines (Basel) 2022; 10:vaccines10060833. [PMID: 35746441 PMCID: PMC9231243 DOI: 10.3390/vaccines10060833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/13/2022] [Accepted: 05/19/2022] [Indexed: 12/12/2022] Open
Abstract
Many microbes of concern to human health remain without vaccines. We have developed a whole-microbe inactivation technology that enables us to rapidly inactivate large quantities of a pathogen while retaining epitopes that were destroyed by previous inactivation methods. The method that we call UVC-MDP inactivation can be used to make whole-cell vaccines with increased potency. We and others are exploring the possibility of using improved irradiation-inactivation technologies to develop whole-cell vaccines for numerous antibiotic-resistant microbes. Here, we apply UVC-MDP to produce candidate MRSA vaccines which we test in a stringent tibia implant model of infection challenged with a virulent MSRA strain. We report high levels of clearance in the model and observe a pattern of protection that correlates with the immunogen protein profile used for vaccination.
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Affiliation(s)
- Stephen J. Dollery
- Biological Mimetics, Inc., Frederick, MD 21702, USA; (T.J.W.); (J.K.T.); (R.V.B.); (N.J.P.E.R.T.); (D.A.M.); (G.J.T.)
- Correspondence:
| | - Janette M. Harro
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; (J.M.H.); (B.P.W.); (P.C.K.)
| | - Taralyn J. Wiggins
- Biological Mimetics, Inc., Frederick, MD 21702, USA; (T.J.W.); (J.K.T.); (R.V.B.); (N.J.P.E.R.T.); (D.A.M.); (G.J.T.)
| | - Brendan P. Wille
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; (J.M.H.); (B.P.W.); (P.C.K.)
| | - Peter C. Kim
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; (J.M.H.); (B.P.W.); (P.C.K.)
| | - John K. Tobin
- Biological Mimetics, Inc., Frederick, MD 21702, USA; (T.J.W.); (J.K.T.); (R.V.B.); (N.J.P.E.R.T.); (D.A.M.); (G.J.T.)
| | - Ruth V. Bushnell
- Biological Mimetics, Inc., Frederick, MD 21702, USA; (T.J.W.); (J.K.T.); (R.V.B.); (N.J.P.E.R.T.); (D.A.M.); (G.J.T.)
| | - Naomi J. P. E. R. Tasker
- Biological Mimetics, Inc., Frederick, MD 21702, USA; (T.J.W.); (J.K.T.); (R.V.B.); (N.J.P.E.R.T.); (D.A.M.); (G.J.T.)
| | - David A. MacLeod
- Biological Mimetics, Inc., Frederick, MD 21702, USA; (T.J.W.); (J.K.T.); (R.V.B.); (N.J.P.E.R.T.); (D.A.M.); (G.J.T.)
| | - Gregory J. Tobin
- Biological Mimetics, Inc., Frederick, MD 21702, USA; (T.J.W.); (J.K.T.); (R.V.B.); (N.J.P.E.R.T.); (D.A.M.); (G.J.T.)
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4
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Leshem T, Schnall BS, Azrad M, Baum M, Rokney A, Peretz A. Incidence of biofilm formation among MRSA and MSSA clinical isolates from hospitalized patients in Israel. J Appl Microbiol 2022; 133:922-929. [PMID: 35503533 PMCID: PMC9540986 DOI: 10.1111/jam.15612] [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: 01/25/2022] [Revised: 04/25/2022] [Accepted: 04/29/2022] [Indexed: 12/01/2022]
Abstract
Aim To assess the biofilm‐producing capacities of Staphylococcus aureus strains isolated from hospitalized patients in Israel. Methods and Results A total of 16 S. aureus (80 MRSA and 83 MSSA) from screening (nasal swab) and clinical samples (blood and wounds) were characterized. Biofilm‐producing capacities were determined using two different biofilm detection assays: Congo Red agar (CRA) and microtiter plate (MtP). In addition, a real‐time PCR analysis was performed to detect the presence of biofilm‐associated genes (icaA and icaD) and mecA gene. The two assays showed similar biofilm production pattern (28.2% agreement). MRSA strains tended to be greater biofilm‐producers than MSSA strains. The presence of mecA was associated with biofilm production (p = 0.030). Additionally, bacteria isolated from blood samples produced less biofilm compared to those from other sources. Finally, no association was found between icaA and icaD presence and biofilm production. Conclusion This study supports earlier assumptions that biofilm formation depends strongly on environmental conditions. Significance and Impact of Study This study significantly improved our knowledge on the biofilm production capacity of S. aureus strains in Israel. Moreover, it revealed an association between the mecA gene and biofilm production. Finally, this study underscores the importance of further research to evaluate risk factors for biofilm production.
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Affiliation(s)
- Tamar Leshem
- Baruch Padeh Medical Center, Clinical Microbiology Laboratory, Poriya, Tiberias, 1528001, Israel
| | | | - Maya Azrad
- Baruch Padeh Medical Center, Clinical Microbiology Laboratory, Poriya, Tiberias, 1528001, Israel
| | - Motti Baum
- Staphylococcus aureus National Reference Center, Israel Ministry of Health, Jerusalem, Israel
| | - Assaf Rokney
- Staphylococcus aureus National Reference Center, Israel Ministry of Health, Jerusalem, Israel
| | - Avi Peretz
- Baruch Padeh Medical Center, Clinical Microbiology Laboratory, Poriya, Tiberias, 1528001, Israel.,Azrieli Faculty of Medicine, Bar Ilan University, Safed, 1311502, Israel
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5
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Kaur H, Kaur A, Soni SK, Rishi P. Microbially-derived cocktail of carbohydrases as an anti-biofouling agents: a 'green approach'. BIOFOULING 2022; 38:455-481. [PMID: 35673761 DOI: 10.1080/08927014.2022.2085566] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 05/12/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Enzymes, also known as biocatalysts, display vital properties like high substrate specificity, an eco-friendly nature, low energy inputs, and cost-effectiveness. Among their numerous known applications, enzymes that can target biofilms or their components are increasingly being investigated for their anti-biofouling action, particularly in healthcare, food manufacturing units and environmental applications. Enzymes can target biofilms at different levels like during the attachment of microorganisms, formation of exopolymeric substances (EPS), and their disruption thereafter. In this regard, a consortium of carbohydrases that can target heterogeneous polysaccharides present in the EPS matrix may provide an effective alternative to conventional chemical anti-biofouling methods. Further, for complete annihilation of biofilms, enzymes can be used alone or in conjunction with other antimicrobial agents. Enzymes hold the promise to replace the conventional methods with greener, more economical, and more efficient alternatives. The present article explores the potential and future perspectives of using carbohydrases as effective anti-biofilm agents.
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Affiliation(s)
- Harmanpreet Kaur
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Arashdeep Kaur
- Department of Microbiology, Panjab University, Chandigarh, India
| | | | - Praveen Rishi
- Department of Microbiology, Panjab University, Chandigarh, India
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Synthetic carbohydrate-based cell wall components from Staphylococcus aureus. DRUG DISCOVERY TODAY. TECHNOLOGIES 2021; 38:35-43. [PMID: 34895639 DOI: 10.1016/j.ddtec.2021.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/17/2020] [Accepted: 01/19/2021] [Indexed: 12/12/2022]
Abstract
Glycopolymers are found surrounding the outer layer of many bacterial species. The first uses as immunogenic component in vaccines are reported since the beginning of the XX century, but it is only in the last decades that glycoconjugate based vaccines have been effectively applied for controlling and preventing several infectious diseases, such as H. influenzae type b (Hib), N. meningitidis, S. pneumoniae or group B Streptococcus. Methicillin resistant S. aureus (MRSA) strains has been appointed by the WHO as one of those pathogens, for which new treatments are urgently needed. Herein we present an overview of the carbohydrate-based cell wall polymers associated with different S. aureus strains and the related affords to deliver well-defined fragments through synthetic chemistry.
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7
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Rumpf C, Lange J, Schwartbeck B, Kahl BC. Staphylococcus aureus and Cystic Fibrosis-A Close Relationship. What Can We Learn from Sequencing Studies? Pathogens 2021; 10:pathogens10091177. [PMID: 34578208 PMCID: PMC8466686 DOI: 10.3390/pathogens10091177] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 01/13/2023] Open
Abstract
Staphylococcus aureus is next to Pseudomonas aeruginosa the most isolated pathogen from the airways of cystic fibrosis (CF) patients, who are often infected by a dominant S. aureus clone for extended periods. To be able to persist, the pathogen has to adapt to the hostile niche of the airways to counteract host defence, antibiotic therapy and the competition with coinfecting pathogens. S. aureus is equipped with many virulence factors including adhesins, toxins that are localized on the chromosome, on plasmids or are phage-related. S. aureus is especially versatile and adaptation and evolution of the pathogen occurs by the acquisition of new genes by horizontal gene transfer (HGT), changes in nucleotides (single nucleotide variations, SNVs) that can cause a selective advantage for the bacteria and become fixed in subpopulations. Methicillin-resistant S. aureus are a special threat to CF patients due to the more severe lung disease occurring in infected patients. Today, with decreasing costs for sequencing, more and more studies using S. aureus isolates cultured from CF patients are being published, which use whole genome sequencing (WGS), multilocus sequence typing (MLST) or spa-sequence typing (spa-typing) to follow the population dynamics of S. aureus, elucidate the underlying mechanisms of phenotypic variants, newly acquired resistance or adaptation to the host response in this particular niche. In the first part of this review, an introduction to the genetic make-up and the pathogenesis of S. aureus with respect to CF is provided. The second part presents an overview of recent studies and their findings using genotypic methods such as single or multilocus sequencing and whole genome sequencing, which identify factors contributing to the adaptation of S. aureus and its evolution in the airways of individuals with CF.
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8
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Bai X, Nakatsu CH, Bhunia AK. Bacterial Biofilms and Their Implications in Pathogenesis and Food Safety. Foods 2021; 10:2117. [PMID: 34574227 PMCID: PMC8472614 DOI: 10.3390/foods10092117] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 08/21/2021] [Accepted: 08/30/2021] [Indexed: 12/28/2022] Open
Abstract
Biofilm formation is an integral part of the microbial life cycle in nature. In food processing environments, bacterial transmissions occur primarily through raw or undercooked foods and by cross-contamination during unsanitary food preparation practices. Foodborne pathogens form biofilms as a survival strategy in various unfavorable environments, which also become a frequent source of recurrent contamination and outbreaks of foodborne illness. Instead of focusing on bacterial biofilm formation and their pathogenicity individually, this review discusses on a molecular level how these two physiological processes are connected in several common foodborne pathogens such as Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica and Escherichia coli. In addition, biofilm formation by Pseudomonas aeruginosa is discussed because it aids the persistence of many foodborne pathogens forming polymicrobial biofilms on food contact surfaces, thus significantly elevating food safety and public health concerns. Furthermore, in-depth analyses of several bacterial molecules with dual functions in biofilm formation and pathogenicity are highlighted.
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Affiliation(s)
- Xingjian Bai
- Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, IN 47907, USA;
| | - Cindy H. Nakatsu
- Department of Agronomy, Purdue University, West Lafayette, IN 47907, USA;
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
| | - Arun K. Bhunia
- Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, IN 47907, USA;
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
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9
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Sweeney E, Harrington NE, Harley Henriques AG, Hassan MM, Crealock-Ashurst B, Smyth AR, Hurley MN, Tormo-Mas MÁ, Harrison F. An ex vivo cystic fibrosis model recapitulates key clinical aspects of chronic Staphylococcus aureus infection. MICROBIOLOGY-SGM 2021; 167. [PMID: 33186093 DOI: 10.1099/mic.0.000987] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Staphylococcus aureus is the most prevalent organism isolated from the airways of people with cystic fibrosis (CF), predominantly early in life. Yet its role in the pathology of lung disease is poorly understood. In mice, and many experiments using cell lines, the bacterium invades cells or interstitium, and forms abscesses. This is at odds with the limited available clinical data: interstitial bacteria are rare in CF biopsies and abscesses are highly unusual. Bacteria instead appear to localize in mucus plugs in the lumens of bronchioles. We show that, in an established ex vivo model of CF infection comprising porcine bronchiolar tissue and synthetic mucus, S. aureus demonstrates clinically significant characteristics including colonization of the airway lumen, with preferential localization as multicellular aggregates in mucus, initiation of a small colony variant phenotype and increased antibiotic tolerance of tissue-associated aggregates. Tissue invasion and abscesses were not observed. Our results may inform ongoing debates relating to clinical responses to S. aureus in people with CF.
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Affiliation(s)
- Esther Sweeney
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | | | | | - Marwa M Hassan
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.,Department of Pathology and Infectious Diseases, School of Veterinary Medicine, University of Surrey, Guildford, UK
| | | | - Alan R Smyth
- Division of Child Health, Obstetrics and Gynecology, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Matthew N Hurley
- Paediatric Respiratory Medicine, Nottingham Children's Hospital, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - María Ángeles Tormo-Mas
- Instituto de Investigación Sanitaria La Fe, Avenida Fernando Abril Martorell, 106 Torre A Lab. 6.13, 46026 Valencia, Spain
| | - Freya Harrison
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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10
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Antistaphylococcal Activity of the FtsZ Inhibitor C109. Pathogens 2021; 10:pathogens10070886. [PMID: 34358036 PMCID: PMC8308607 DOI: 10.3390/pathogens10070886] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/08/2021] [Accepted: 07/10/2021] [Indexed: 01/22/2023] Open
Abstract
Staphylococcus aureus infections represent a great concern due to their versatility and involvement in different types of diseases. The shortage of available clinical options, especially to treat multiresistant strains, makes the discovery of new effective compounds essential. Here we describe the activity of the previously described cell division inhibitor C109 against methicillin-sensitive and -resistant S. aureus strains. Antibiofilm activity was assessed using microtiter plates, confocal microscopy, and in an in vitro biofilm wound model. The ability of C109 to block FtsZ GTPase activity and polymerization was tested in vitro. Altogether, the results show that the FtsZ inhibitor C109 has activity against a wide range of S. aureus strains and support its use as an antistaphylococcal compound.
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11
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Seeberger PH. Discovery of Semi- and Fully-Synthetic Carbohydrate Vaccines Against Bacterial Infections Using a Medicinal Chemistry Approach. Chem Rev 2021; 121:3598-3626. [PMID: 33794090 PMCID: PMC8154330 DOI: 10.1021/acs.chemrev.0c01210] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Indexed: 12/13/2022]
Abstract
The glycocalyx, a thick layer of carbohydrates, surrounds the cell wall of most bacterial and parasitic pathogens. Recognition of these unique glycans by the human immune system results in destruction of the invaders. To elicit a protective immune response, polysaccharides either isolated from the bacterial cell surface or conjugated with a carrier protein, for T-cell help, are administered. Conjugate vaccines based on isolated carbohydrates currently protect millions of people against Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitides infections. Active pharmaceutical ingredients (APIs) are increasingly discovered by medicinal chemistry and synthetic in origin, rather than isolated from natural sources. Converting vaccines from biologicals to pharmaceuticals requires a fundamental understanding of how the human immune system recognizes carbohydrates and could now be realized. To illustrate the chemistry-based approach to vaccine discovery, I summarize efforts focusing on synthetic glycan-based medicinal chemistry to understand the mammalian antiglycan immune response and define glycan epitopes for novel synthetic glycoconjugate vaccines against Streptococcus pneumoniae, Clostridium difficile, Klebsiella pneumoniae, and other bacteria. The chemical tools described here help us gain fundamental insights into how the human system recognizes carbohydrates and drive the discovery of carbohydrate vaccines.
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12
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Recent chemical syntheses of bacteria related oligosaccharides using modern expeditious approaches. Carbohydr Res 2021; 507:108295. [PMID: 34271477 DOI: 10.1016/j.carres.2021.108295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/15/2021] [Accepted: 03/16/2021] [Indexed: 12/22/2022]
Abstract
Apart from some essential and crucial roles in life processes carbohydrates also are involved in a few detrimental courses of action related to human health, like infections by pathogenic microbes, cancer metastasis, transplanted tissue rejection, etc. Regarding management of pathogenesis by microbes, keeping in mind of multi drug-resistant bacteria and epidemic or endemic incidents, preventive measure by vaccination is the best pathway as also recommended by the WHO; by vaccination, eradication of bacterial diseases is also possible. Although some valid vaccines based on attenuated bacterial cells or isolated pure polysaccharide-antigens or the corresponding conjugates thereof are available in the market for prevention of several bacterial diseases, but these are not devoid of some disadvantages also. In order to develop improved conjugate T-cell dependent vaccines oligosaccharides related to bacterial antigens are synthesized and converted to the corresponding carrier protein conjugates. Marketed Cuban Quimi-Hib is such a vaccine being used since 2004 to resist Haemophilus influenza b infections. During nearly the past two decades research is going on worldwide for improved synthesis of bacteria related oligosaccharides or polysaccharides towards development of such semisynthetic or synthetic glycoconjugate vaccines. The present dissertation is an endeavour to encompass the recent syntheses of several pathogenic bacterial oligosaccharides or polysaccharides, made during the past ten-eleven years with special reference to modern expeditious syntheses.
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13
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Jasińska E, Bogut A, Magryś A, Olender A. Evaluation of the role of staphylococci in the pathomechanism of conjunctivitis. Int Ophthalmol 2021; 41:2585-2600. [PMID: 33778922 PMCID: PMC8238708 DOI: 10.1007/s10792-021-01818-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/16/2021] [Indexed: 11/27/2022]
Abstract
Purpose Determination of the association between ica genes and phenotypic biofilm formation in staphylococcal isolates involved in conjunctivitis, their antibiotic resistance as well as detection of selected virulence characteristics: adhesion to epithelial cells and in vitro cytotoxicity. Methods The study included 26 Staphylococcus aureus (SA) and 26 Staphylococcus epidermidis (SE) isolates. The presence of icaAD genes and ica operon was determined by the PCR assay. Phenotypic biofilm formation was verified using the microtitre plate assay. Antibiotic resistance was performed using the disc diffusion method. Staphylococcal ability to attach to host cells was assessed by flow cytometry. Cytotoxicity on epithelial cells was evaluated by LDH assay. Results The ica genes were detected in 26.9% of SE and in 42.3% of SA isolates. Only 15.3% of isolates (SE) were positive for both the icaAD and the ica operon. Phenotypically, 19.2% of SE isolates were strong biofilm producers, among which three were both icaAD- and ica operon-positive. About 26.9% of SA isolates were strong biofilm producers. Methicillin resistance (MR) was detected in 34.6% of SE and 26.9% of SA isolates. About 75% of MR isolates were multidrug resistant. SA isolates adhered to host cells more extensively than SE. SA isolates released higher level of LDH than SE. Conclusions Adherence abilities were commonly observed in staphylococci associated with conjunctivitis. However, low prevalence of isolates positive for a complete and functional ica locus and low prevalence of strong biofilm producers was detected. SA adhered to a greater extent to eukaryotic cells than SE and were more cytotoxic.
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Affiliation(s)
- Ewa Jasińska
- Department of General Ophthalmology, Medical University of Lublin, Lublin, Poland
| | - Agnieszka Bogut
- Chair and Department of Medical Microbiology, Medical University of Lublin, Lublin, Poland.
| | - Agnieszka Magryś
- Chair and Department of Medical Microbiology, Medical University of Lublin, Lublin, Poland
| | - Alina Olender
- Chair and Department of Medical Microbiology, Medical University of Lublin, Lublin, Poland
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14
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Loera-Muro A, Guerrero-Barrera A, Tremblay D N Y, Hathroubi S, Angulo C. Bacterial biofilm-derived antigens: a new strategy for vaccine development against infectious diseases. Expert Rev Vaccines 2021; 20:385-396. [PMID: 33606569 DOI: 10.1080/14760584.2021.1892492] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Microorganisms can develop into a social organization known as biofilms and these communities can be found in virtually all types of environment on earth. In biofilms, cells grow as multicellular communities held together by a self-produced extracellular matrix. Living within a biofilm allows for the emergence of specific properties for these cells that their planktonic counterparts do not have. Furthermore, biofilms are the cause of several infectious diseases and are frequently inhabited by multi-species. These interactions between microbial species are often critical for the biofilm process. Despite the importance of biofilms in disease, vaccine antigens are typically prepared from bacteria grown as planktonic cells under laboratory conditions. Vaccines based on planktonic bacteria may not provide optimal protection against biofilm-driven infections. AREAS COVERED In this review, we will present an overview of biofilm formation, what controls this mode of growth, and recent vaccine development targeting biofilms. EXPERT OPINION Previous and ongoing research provides evidence that vaccine formulation with antigens derived from biofilms is a promising approach to prevent infectious diseases and can enhance the protective efficacy of existing vaccines. Therefore, research focusing on the identification of biofilm-derived antigens merits further investigations.
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Affiliation(s)
- Abraham Loera-Muro
- CONACYT-CIBNOR, Centro de Investigaciones Biológicas del Noroeste, SC. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, BCS, México
| | - Alma Guerrero-Barrera
- Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, Colonia Ciudad Universitaria, Aguascalientes, AGS, México
| | - Yannick Tremblay D N
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Skander Hathroubi
- Cluster of Excellence "Matters of Activity.Image Space Material", Humboldt-Universität zu Berlin, Unter den Liden 6, 10099, Berlin, Germany.,Institüt Für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Carlos Angulo
- Immunology & Vaccinology Group. Centro de Investigaciones Biológicas del Noroeste, SC. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, BCS, México
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15
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Pidwill GR, Gibson JF, Cole J, Renshaw SA, Foster SJ. The Role of Macrophages in Staphylococcus aureus Infection. Front Immunol 2021; 11:620339. [PMID: 33542723 PMCID: PMC7850989 DOI: 10.3389/fimmu.2020.620339] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/02/2020] [Indexed: 12/23/2022] Open
Abstract
Staphylococcus aureus is a member of the human commensal microflora that exists, apparently benignly, at multiple sites on the host. However, as an opportunist pathogen it can also cause a range of serious diseases. This requires an ability to circumvent the innate immune system to establish an infection. Professional phagocytes, primarily macrophages and neutrophils, are key innate immune cells which interact with S. aureus, acting as gatekeepers to contain and resolve infection. Recent studies have highlighted the important roles of macrophages during S. aureus infections, using a wide array of killing mechanisms. In defense, S. aureus has evolved multiple strategies to survive within, manipulate and escape from macrophages, allowing them to not only subvert but also exploit this key element of our immune system. Macrophage-S. aureus interactions are multifaceted and have direct roles in infection outcome. In depth understanding of these host-pathogen interactions may be useful for future therapeutic developments. This review examines macrophage interactions with S. aureus throughout all stages of infection, with special emphasis on mechanisms that determine infection outcome.
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Affiliation(s)
- Grace R Pidwill
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom.,Florey Institute, University of Sheffield, Sheffield, United Kingdom
| | - Josie F Gibson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom.,Florey Institute, University of Sheffield, Sheffield, United Kingdom.,The Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Joby Cole
- Florey Institute, University of Sheffield, Sheffield, United Kingdom.,Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Stephen A Renshaw
- Florey Institute, University of Sheffield, Sheffield, United Kingdom.,The Bateson Centre, University of Sheffield, Sheffield, United Kingdom.,Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Simon J Foster
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom.,Florey Institute, University of Sheffield, Sheffield, United Kingdom
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16
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Nguyen HTT, Nguyen TH, Otto M. The staphylococcal exopolysaccharide PIA - Biosynthesis and role in biofilm formation, colonization, and infection. Comput Struct Biotechnol J 2020; 18:3324-3334. [PMID: 33240473 PMCID: PMC7674160 DOI: 10.1016/j.csbj.2020.10.027] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/23/2020] [Accepted: 10/25/2020] [Indexed: 12/20/2022] Open
Abstract
PIA is a key extracellular matrix component in staphylococci and other bacteria. PIA is a cationic, partially deacetylated N-acetylglucosamine polymer. PIA has a major role in bacterial biofilms and biofilm-associated infection.
Exopolysaccharide is a key part of the extracellular matrix that contributes to important mechanisms of bacterial pathogenicity, most notably biofilm formation and immune evasion. In the human pathogens Staphylococcus aureus and S. epidermidis, as well as in many other staphylococcal species, the only exopolysaccharide is polysaccharide intercellular adhesin (PIA), a cationic, partially deacetylated homopolymer of N-acetylglucosamine, whose biosynthetic machinery is encoded in the ica locus. PIA production is strongly dependent on environmental conditions and controlled by many regulatory systems. PIA contributes significantly to staphylococcal biofilm formation and immune evasion mechanisms, such as resistance to antimicrobial peptides and ingestion and killing by phagocytes, and presence of the ica genes is associated with infectivity. Due to its role in pathogenesis, PIA has raised considerable interest as a potential vaccine component or target.
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Affiliation(s)
- Hoai T T Nguyen
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda 20814, MD, USA.,School of Biotechnology, International University, Vietnam National University of Ho Chi Minh City, Khu Pho 6, Thu Duc, Ho Chi Minh City, Viet Nam
| | - Thuan H Nguyen
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda 20814, MD, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda 20814, MD, USA
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18
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Schilcher K, Horswill AR. Staphylococcal Biofilm Development: Structure, Regulation, and Treatment Strategies. Microbiol Mol Biol Rev 2020. [PMID: 32792334 DOI: 10.1128/mmbr.00026-19/asset/e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
In many natural and clinical settings, bacteria are associated with some type of biotic or abiotic surface that enables them to form biofilms, a multicellular lifestyle with bacteria embedded in an extracellular matrix. Staphylococcus aureus and Staphylococcus epidermidis, the most frequent causes of biofilm-associated infections on indwelling medical devices, can switch between an existence as single free-floating cells and multicellular biofilms. During biofilm formation, cells first attach to a surface and then multiply to form microcolonies. They subsequently produce the extracellular matrix, a hallmark of biofilm formation, which consists of polysaccharides, proteins, and extracellular DNA. After biofilm maturation into three-dimensional structures, the biofilm community undergoes a disassembly process that leads to the dissemination of staphylococcal cells. As biofilms are dynamic and complex biological systems, staphylococci have evolved a vast network of regulatory mechanisms to modify and fine-tune biofilm development upon changes in environmental conditions. Thus, biofilm formation is used as a strategy for survival and persistence in the human host and can serve as a reservoir for spreading to new infection sites. Moreover, staphylococcal biofilms provide enhanced resilience toward antibiotics and the immune response and impose remarkable therapeutic challenges in clinics worldwide. This review provides an overview and an updated perspective on staphylococcal biofilms, describing the characteristic features of biofilm formation, the structural and functional properties of the biofilm matrix, and the most important mechanisms involved in the regulation of staphylococcal biofilm formation. Finally, we highlight promising strategies and technologies, including multitargeted or combinational therapies, to eradicate staphylococcal biofilms.
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Affiliation(s)
- Katrin Schilcher
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
- Department of Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado, USA
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19
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Staphylococcal Biofilm Development: Structure, Regulation, and Treatment Strategies. Microbiol Mol Biol Rev 2020; 84:84/3/e00026-19. [PMID: 32792334 DOI: 10.1128/mmbr.00026-19] [Citation(s) in RCA: 262] [Impact Index Per Article: 65.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In many natural and clinical settings, bacteria are associated with some type of biotic or abiotic surface that enables them to form biofilms, a multicellular lifestyle with bacteria embedded in an extracellular matrix. Staphylococcus aureus and Staphylococcus epidermidis, the most frequent causes of biofilm-associated infections on indwelling medical devices, can switch between an existence as single free-floating cells and multicellular biofilms. During biofilm formation, cells first attach to a surface and then multiply to form microcolonies. They subsequently produce the extracellular matrix, a hallmark of biofilm formation, which consists of polysaccharides, proteins, and extracellular DNA. After biofilm maturation into three-dimensional structures, the biofilm community undergoes a disassembly process that leads to the dissemination of staphylococcal cells. As biofilms are dynamic and complex biological systems, staphylococci have evolved a vast network of regulatory mechanisms to modify and fine-tune biofilm development upon changes in environmental conditions. Thus, biofilm formation is used as a strategy for survival and persistence in the human host and can serve as a reservoir for spreading to new infection sites. Moreover, staphylococcal biofilms provide enhanced resilience toward antibiotics and the immune response and impose remarkable therapeutic challenges in clinics worldwide. This review provides an overview and an updated perspective on staphylococcal biofilms, describing the characteristic features of biofilm formation, the structural and functional properties of the biofilm matrix, and the most important mechanisms involved in the regulation of staphylococcal biofilm formation. Finally, we highlight promising strategies and technologies, including multitargeted or combinational therapies, to eradicate staphylococcal biofilms.
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20
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Bernardy EE, Petit RA, Raghuram V, Alexander AM, Read TD, Goldberg JB. Genotypic and Phenotypic Diversity of Staphylococcus aureus Isolates from Cystic Fibrosis Patient Lung Infections and Their Interactions with Pseudomonas aeruginosa. mBio 2020; 11. [PMID: 32576671 DOI: 10.31234/osf.io/9whp4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023] Open
Abstract
Staphylococcus aureus has recently overtaken Pseudomonas aeruginosa as the most commonly recognized bacterial pathogen that infects the respiratory tracts of individuals with the genetic disease cystic fibrosis (CF) in the United States. Most studies of S. aureus in CF patient lung infections have focused on a few isolates, often exclusively laboratory-adapted strains, and how they are killed by P. aeruginosa Less is known about the diversity of S. aureus CF patient lung isolates in terms of both their virulence and their interaction with P. aeruginosa To begin to address this gap, we recently sequenced 64 clinical S. aureus isolates and a reference isolate, JE2. Here, we analyzed the antibiotic resistance genotypes, sequence types, clonal complexes, spa types, agr types, and presence/absence of other known virulence factor genes of these isolates. We hypothesized that virulence phenotypes of S. aureus, namely, toxin production and the mucoid phenotype, would be lost in these isolates due to adaptation in the CF patient lung. In contrast to these expectations, we found that most isolates can lyse both rabbit and sheep blood (67.7%) and produce polysaccharide (69.2%), suggesting that these phenotypes were not lost during adaptation to the CF lung. We also identified three distinct phenotypic groups of S. aureus based on their survival in the presence of nonmucoid P. aeruginosa laboratory strain PAO1 and its mucoid derivative. Altogether, our work provides greater insight into the diversity of S. aureus isolates from CF patients, specifically the distribution of important virulence factors and their interaction with P. aeruginosa, all of which have implications in patient health.IMPORTANCEStaphylococcus aureus is now the most frequently detected recognized pathogen in the lungs of individuals who have cystic fibrosis (CF) in the United States, followed closely by Pseudomonas aeruginosa When these pathogens are found to coinfect the CF lung, patients have a significantly worse prognosis. While P. aeruginosa has been rigorously studied in the context of bacterial pathogenesis in CF, less is known about S. aureus Here, we present an in-depth study of 64 S. aureus clinical isolates from CF patients, for which we investigated genetic diversity utilizing whole-genome sequencing, virulence phenotypes, and interactions with P. aeruginosa We found that S. aureus isolated from CF lungs are phylogenetically diverse; most retain known virulence factors and vary in their interactions with P. aeruginosa (i.e., they range from being highly sensitive to P. aeruginosa to completely tolerant to it). Deepening our understanding of how S. aureus responds to its environment and other microbes in the CF lung will enable future development of effective treatments and preventative measures against these formidable infections.
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Affiliation(s)
- Eryn E Bernardy
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Robert A Petit
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
| | - Vishnu Raghuram
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Ashley M Alexander
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Timothy D Read
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
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21
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Bernardy EE, Petit RA, Raghuram V, Alexander AM, Read TD, Goldberg JB. Genotypic and Phenotypic Diversity of Staphylococcus aureus Isolates from Cystic Fibrosis Patient Lung Infections and Their Interactions with Pseudomonas aeruginosa. mBio 2020; 11:mBio.00735-20. [PMID: 32576671 PMCID: PMC7315118 DOI: 10.1128/mbio.00735-20] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Staphylococcus aureus has recently overtaken Pseudomonas aeruginosa as the most commonly recognized bacterial pathogen that infects the respiratory tracts of individuals with the genetic disease cystic fibrosis (CF) in the United States. Most studies of S. aureus in CF patient lung infections have focused on a few isolates, often exclusively laboratory-adapted strains, and how they are killed by P. aeruginosa Less is known about the diversity of S. aureus CF patient lung isolates in terms of both their virulence and their interaction with P. aeruginosa To begin to address this gap, we recently sequenced 64 clinical S. aureus isolates and a reference isolate, JE2. Here, we analyzed the antibiotic resistance genotypes, sequence types, clonal complexes, spa types, agr types, and presence/absence of other known virulence factor genes of these isolates. We hypothesized that virulence phenotypes of S. aureus, namely, toxin production and the mucoid phenotype, would be lost in these isolates due to adaptation in the CF patient lung. In contrast to these expectations, we found that most isolates can lyse both rabbit and sheep blood (67.7%) and produce polysaccharide (69.2%), suggesting that these phenotypes were not lost during adaptation to the CF lung. We also identified three distinct phenotypic groups of S. aureus based on their survival in the presence of nonmucoid P. aeruginosa laboratory strain PAO1 and its mucoid derivative. Altogether, our work provides greater insight into the diversity of S. aureus isolates from CF patients, specifically the distribution of important virulence factors and their interaction with P. aeruginosa, all of which have implications in patient health.IMPORTANCEStaphylococcus aureus is now the most frequently detected recognized pathogen in the lungs of individuals who have cystic fibrosis (CF) in the United States, followed closely by Pseudomonas aeruginosa When these pathogens are found to coinfect the CF lung, patients have a significantly worse prognosis. While P. aeruginosa has been rigorously studied in the context of bacterial pathogenesis in CF, less is known about S. aureus Here, we present an in-depth study of 64 S. aureus clinical isolates from CF patients, for which we investigated genetic diversity utilizing whole-genome sequencing, virulence phenotypes, and interactions with P. aeruginosa We found that S. aureus isolated from CF lungs are phylogenetically diverse; most retain known virulence factors and vary in their interactions with P. aeruginosa (i.e., they range from being highly sensitive to P. aeruginosa to completely tolerant to it). Deepening our understanding of how S. aureus responds to its environment and other microbes in the CF lung will enable future development of effective treatments and preventative measures against these formidable infections.
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Affiliation(s)
- Eryn E Bernardy
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Robert A Petit
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
| | - Vishnu Raghuram
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Ashley M Alexander
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Timothy D Read
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
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22
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Eddenden A, Kitova EN, Klassen JS, Nitz M. An Inactive Dispersin B Probe for Monitoring PNAG Production in Biofilm Formation. ACS Chem Biol 2020; 15:1204-1211. [PMID: 31917539 DOI: 10.1021/acschembio.9b00907] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The bacterial exopolysaccharide poly-β-1,6-N-acetylglucosamine is a major extracellular matrix component in biofilms of both Gram-positive and Gram-negative organisms. We have leveraged the specificity of the biofilm-dispersing glycoside hydrolase Dispersin B (DspB) to generate a probe (Dispersin B PNAG probe, DiPP) for monitoring PNAG production and localization during biofilm formation. Mutation of the active site of Dispersin B gave DiPP, which was an effective probe despite its low affinity for PNAG oligosaccharides (KD ∼ 1-10 mM). Imaging of PNAG-dependent and -independent biofilms stained with a fluorescent-protein fusion of DiPP (GFP-DiPP) demonstrated the specificity of the probe for the structure of PNAG on both single-cell and biofilm levels, indicating a high local concentration of PNAG at the bacterial cell surface. Through quantitative bacterial cell binding assays and confocal microscopy analysis using GFP-DiPP, discrete areas of local high concentrations of PNAG were detected on the surface of early log phase cells. These distinct areas were seen to grow, slough from cells, and accumulate in interbacterial regions over the course of several cell divisions, showing the development of a PNAG-dependent biofilm. A potential helical distribution of staining was also noted, suggesting some degree of organization of PNAG production at the cell surface prior to cell aggregation. Together, these experiments shed light on the early stages of PNAG-dependent biofilm formation and demonstrate the value of a low-affinity-high-specificity probe for monitoring the production of bacterial exopolysaccharides.
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Affiliation(s)
- Alexander Eddenden
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, Ontario, Canada M5S 3H6
| | - Elena N. Kitova
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr. Edmonton, Alberta, Canada T6G 2G2
| | - John S. Klassen
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr. Edmonton, Alberta, Canada T6G 2G2
| | - Mark Nitz
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, Ontario, Canada M5S 3H6
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Flannery A, Le Berre M, Pier GB, O’Gara JP, Kilcoyne M. Glycomics Microarrays Reveal Differential In Situ Presentation of the Biofilm Polysaccharide Poly- N-acetylglucosamine on Acinetobacter baumannii and Staphylococcus aureus Cell Surfaces. Int J Mol Sci 2020; 21:ijms21072465. [PMID: 32252300 PMCID: PMC7177611 DOI: 10.3390/ijms21072465] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 03/30/2020] [Accepted: 04/01/2020] [Indexed: 02/06/2023] Open
Abstract
The biofilm component poly-N-acetylglucosamine (PNAG) is an important virulence determinant in medical-device-related infections caused by ESKAPE group pathogens including Gram-positive Staphylococcus aureus and Gram-negative Acinetobacter baumannii. PNAG presentation on bacterial cell surfaces and its accessibility for host interactions are not fully understood. We employed a lectin microarray to examine PNAG surface presentation and interactions on methicillin-sensitive (MSSA) and methicillin-resistant S. aureus (MRSA) and a clinical A. baumannii isolate. Purified PNAG bound to wheatgerm agglutinin (WGA) and succinylated WGA (sWGA) lectins only. PNAG was the main accessible surface component on MSSA but was relatively inaccessible on the A. baumannii surface, where it modulated the presentation of other surface molecules. Carbohydrate microarrays demonstrated similar specificities of S. aureus and A. baumannii for their most intensely binding carbohydrates, including 3' and 6'sialyllactose, but differences in moderately binding ligands, including blood groups A and B. An N-acetylglucosamine-binding lectin function which binds to PNAG identified on the A. baumannii cell surface may contribute to biofilm structure and PNAG surface presentation on A. baumannii. Overall, these data indicated differences in PNAG presentation and accessibility for interactions on Gram-positive and Gram-negative cell surfaces which may play an important role in biofilm-mediated pathogenesis.
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Affiliation(s)
- Andrea Flannery
- Carbohydrate Signalling Group, Discipline of Microbiology, National University of Ireland Galway, H91 TK33 Galway, Ireland;
- Infectious Disease Laboratory, Discipline of Microbiology, National University of Ireland Galway, H91 TK33 Galway, Ireland;
| | - Marie Le Berre
- Advanced Glycoscience Research Cluster, School of Natural Sciences, National University of Ireland Galway, H91 TK33 Galway, Ireland;
| | - Gerald B. Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | - James P. O’Gara
- Infectious Disease Laboratory, Discipline of Microbiology, National University of Ireland Galway, H91 TK33 Galway, Ireland;
| | - Michelle Kilcoyne
- Carbohydrate Signalling Group, Discipline of Microbiology, National University of Ireland Galway, H91 TK33 Galway, Ireland;
- Advanced Glycoscience Research Cluster, School of Natural Sciences, National University of Ireland Galway, H91 TK33 Galway, Ireland;
- Correspondence:
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24
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Riquelme SA, Wong Fok Lung T, Prince A. Pulmonary Pathogens Adapt to Immune Signaling Metabolites in the Airway. Front Immunol 2020; 11:385. [PMID: 32231665 PMCID: PMC7082326 DOI: 10.3389/fimmu.2020.00385] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/18/2020] [Indexed: 12/17/2022] Open
Abstract
A limited number of pulmonary pathogens are able to evade normal mucosal defenses to establish acute infection and then adapt to cause chronic pneumonias. Pathogens, such as Pseudomonas aeruginosa or Staphylococcus aureus, are typically associated with infection in patients with underlying pulmonary disease or damage, such as cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD). To establish infection, bacteria express a well-defined set of so-called virulence factors that facilitate colonization and activate an immune response, gene products that have been identified in murine models. Less well-understood are the adaptive changes that occur over time in vivo, enabling the organisms to evade innate and adaptive immune clearance mechanisms. These colonizers proliferate, generating a population sufficient to provide selection for mutants, such as small colony variants and mucoid variants, that are optimized for long term infection. Such host-adapted strains have evolved in response to selective pressure such as antibiotics and the recruitment of phagocytes at sites of infection and their release of signaling metabolites (e.g., succinate). These metabolites can potentially function as substrates for bacterial growth and but also generate oxidant stress. Whole genome sequencing and quantified expression of selected genes have helped to explain how P. aeruginosa and S. aureus adapt to the presence of these metabolites over the course of in vivo infection. The serial isolation of clonally related strains from patients with cystic fibrosis has provided the opportunity to identify bacterial metabolic pathways that are altered under this immune pressure, such as the anti-oxidant glyoxylate and pentose phosphate pathways, routes contributing to the generation of biofilms. These metabolic pathways and biofilm itself enable the organisms to dissipate oxidant stress, while providing protection from phagocytosis. Stimulation of host immune signaling metabolites by these pathogens drives bacterial adaptation and promotes their persistence in the airways. The inherent metabolic flexibility of P. aeruginosa and S. aureus is a major factor in their success as pulmonary pathogens.
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Affiliation(s)
- Sebastián A Riquelme
- Department of Pediatrics, Columbia University Medical Center, New York, NY, United States
| | - Tania Wong Fok Lung
- Department of Pediatrics, Columbia University Medical Center, New York, NY, United States
| | - Alice Prince
- Department of Pediatrics, Columbia University Medical Center, New York, NY, United States
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25
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Forman A, Pfoh R, Eddenden A, Howell PL, Nitz M. Synthesis of defined mono-de-N-acetylated β-(1→6)-N-acetyl-d-glucosamine oligosaccharides to characterize PgaB hydrolase activity. Org Biomol Chem 2019; 17:9456-9466. [PMID: 31642455 DOI: 10.1039/c9ob02079a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many clinically-relevant biofilm-forming bacterial strains produce partially de-N-acetylated poly-β-(1→6)-N-acetyl-d-glucosamine (dPNAG) as an exopolysaccharide. In Gram-negative bacteria, the periplasmic protein PgaB is responsible for partial de-N-acetylation of PNAG prior to its export to the extracellular space. In addition to de-N-acetylase activity found in the N-terminal domain, PgaB contains a C-terminal hydrolase domain that can disrupt dPNAG-dependent biofilms and hydrolyzes dPNAG but not fully acetylated PNAG. The role of this C-terminal domain in biofilm formation has yet to be determined in vivo. Further characterization of the enzyme's hydrolase activity has been hampered by a lack of specific dPNAG oligosaccharides. Here, we report the synthesis of a defined mono de-N-acetylated dPNAG penta- and hepta-saccharide. Using mass spectrometry analysis and a fluorescence-based thin-layer chromatography (TLC) assay, we found that our defined dPNAG oligosaccharides are hydrolase substrates. In addition to the expected cleavage site, two residues to the reducing side of the de-N-acetylated residue, minor cleavage products on the non-reducing side of the de-N-acetylation site were observed. These findings provide quantitative data to support how PNAG is processed in Gram-negative bacteria.
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Affiliation(s)
- Adam Forman
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, Canada M5S 3H6.
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26
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σ B Inhibits Poly- N-Acetylglucosamine Exopolysaccharide Synthesis and Biofilm Formation in Staphylococcus aureus. J Bacteriol 2019; 201:JB.00098-19. [PMID: 30858304 DOI: 10.1128/jb.00098-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 03/07/2019] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus clinical strains are able to produce at least two distinct types of biofilm matrixes: biofilm matrixes made of the polysaccharide intercellular adhesin (PIA) or poly-N-acetylglucosamine (PNAG), whose synthesis is mediated by the icaADBC locus, and biofilm matrixes built of proteins (polysaccharide independent). σB is a conserved alternative sigma factor that regulates the expression of more than 100 genes in response to changes in environmental conditions. While numerous studies agree that σB is required for polysaccharide-independent biofilms, controversy persists over the role of σB in the regulation of PIA/PNAG-dependent biofilm development. Here, we show that genetically unrelated S. aureus σB-deficient strains produced stronger biofilms under both static and flow conditions and accumulated higher levels of PIA/PNAG exopolysaccharide than their corresponding wild-type strains. The increased accumulation of PIA/PNAG in the σB mutants correlated with a greater accumulation of the IcaC protein showed that it was not due to adjustments in icaADBC operon transcription and/or icaADBC mRNA stability. Overall, our results reveal that in the presence of active σB, the turnover of Ica proteins is accelerated, reducing the synthesis of PIA/PNAG exopolysaccharide and consequently the PIA/PNAG-dependent biofilm formation capacity.IMPORTANCE Due to its multifaceted lifestyle, Staphylococcus aureus needs a complex regulatory network to connect environmental signals with cellular physiology. One particular transcription factor, named σB (SigB), is involved in the general stress response and the expression of virulence factors. For many years, great confusion has existed about the role of σB in the regulation of the biofilm lifestyle in S. aureus Our study demonstrated that σB is not necessary for exopolysaccharide-dependent biofilms and, even more, that S. aureus produces stronger biofilms in the absence of σB The increased accumulation of exopolysaccharide correlates with higher stability of the proteins responsible for its synthesis. The present findings reveal an additional regulatory layer to control biofilm exopolysaccharide synthesis under stress conditions.
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Mohamed N, Timofeyeva Y, Jamrozy D, Rojas E, Hao L, Silmon de Monerri NC, Hawkins J, Singh G, Cai B, Liberator P, Sebastian S, Donald RGK, Scully IL, Jones CH, Creech CB, Thomsen I, Parkhill J, Peacock SJ, Jansen KU, Holden MTG, Anderson AS. Molecular epidemiology and expression of capsular polysaccharides in Staphylococcus aureus clinical isolates in the United States. PLoS One 2019; 14:e0208356. [PMID: 30641545 PMCID: PMC6331205 DOI: 10.1371/journal.pone.0208356] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 11/15/2018] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus capsular polysaccharides (CP) are important virulence factors under evaluation as vaccine antigens. Clinical S. aureus isolates have the biosynthetic capability to express either CP5 or CP8 and an understanding of the relationship between CP genotype/phenotype and S. aureus epidemiology is valuable. Using whole genome sequencing, the clonal relatedness and CP genotype were evaluated for disease-associated S. aureus isolates selected from the Tigecycline Evaluation and Surveillance Trial (T.E.S.T) to represent different geographic regions in the United States (US) during 2004 and 2009–10. Thirteen prominent clonal complexes (CC) were identified, with CC5, 8, 30 and 45 representing >80% of disease isolates. CC5 and CC8 isolates were CP type 5 and, CC30 and CC45 isolates were CP type 8. Representative isolates from prevalent CC were susceptible to in vitro opsonophagocytic killing elicited by anti-CP antibodies, demonstrating that susceptibility to opsonic killing is not linked to the genetic lineage. However, as not all S. aureus isolates may express CP, isolates representing the diversity of disease isolates were assessed for CP production. While approximately 35% of isolates (primarily CC8) did not express CP in vitro, CP expression could be clearly demonstrated in vivo for 77% of a subset of these isolates (n = 20) despite the presence of mutations within the capsule operon. CP expression in vivo was also confirmed indirectly by measuring an increase in CP specific antibodies in mice infected with CP5 or CP8 isolates. Detection of antigen expression in vivo in relevant disease states is important to support the inclusion of these antigens in vaccines. Our findings confirm the validity of CP as vaccine targets and the potential of CP-based vaccines to contribute to S. aureus disease prevention.
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Affiliation(s)
- Naglaa Mohamed
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Yekaterina Timofeyeva
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Dorota Jamrozy
- The Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Eduardo Rojas
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Li Hao
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | | | - Julio Hawkins
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Guy Singh
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Bing Cai
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Paul Liberator
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Shite Sebastian
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Robert G. K. Donald
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Ingrid L. Scully
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - C. Hal Jones
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - C. Buddy Creech
- Vanderbilt Vaccine Research Program, Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Isaac Thomsen
- Vanderbilt Vaccine Research Program, Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Julian Parkhill
- The Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Sharon J. Peacock
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kathrin U. Jansen
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | | | - Annaliesa S. Anderson
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
- * E-mail:
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Little DJ, Pfoh R, Le Mauff F, Bamford NC, Notte C, Baker P, Guragain M, Robinson H, Pier GB, Nitz M, Deora R, Sheppard DC, Howell PL. PgaB orthologues contain a glycoside hydrolase domain that cleaves deacetylated poly-β(1,6)-N-acetylglucosamine and can disrupt bacterial biofilms. PLoS Pathog 2018; 14:e1006998. [PMID: 29684093 PMCID: PMC5933820 DOI: 10.1371/journal.ppat.1006998] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 05/03/2018] [Accepted: 03/29/2018] [Indexed: 11/24/2022] Open
Abstract
Poly-β(1,6)-N-acetyl-D-glucosamine (PNAG) is a major biofilm component of many pathogenic bacteria. The production, modification, and export of PNAG in Escherichia coli and Bordetella species require the protein products encoded by the pgaABCD operon. PgaB is a two-domain periplasmic protein that contains an N-terminal deacetylase domain and a C-terminal PNAG binding domain that is critical for export. However, the exact function of the PgaB C-terminal domain remains unclear. Herein, we show that the C-terminal domains of Bordetella bronchiseptica PgaB (PgaBBb) and E. coli PgaB (PgaBEc) function as glycoside hydrolases. These enzymes hydrolyze purified deacetylated PNAG (dPNAG) from Staphylococcus aureus, disrupt PNAG-dependent biofilms formed by Bordetella pertussis, Staphylococcus carnosus, Staphylococcus epidermidis, and E. coli, and potentiate bacterial killing by gentamicin. Furthermore, we found that PgaBBb was only able to hydrolyze PNAG produced in situ by the E. coli PgaCD synthase complex when an active deacetylase domain was present. Mass spectrometry analysis of the PgaB-hydrolyzed dPNAG substrate showed a GlcN-GlcNAc-GlcNAc motif at the new reducing end of detected fragments. Our 1.76 Å structure of the C-terminal domain of PgaBBb reveals a central cavity within an elongated surface groove that appears ideally suited to recognize the GlcN-GlcNAc-GlcNAc motif. The structure, in conjunction with molecular modeling and site directed mutagenesis led to the identification of the dPNAG binding subsites and D474 as the probable catalytic acid. This work expands the role of PgaB within the PNAG biosynthesis machinery, defines a new glycoside hydrolase family GH153, and identifies PgaB as a possible therapeutic agent for treating PNAG-dependent biofilm infections. From plaque on teeth to infections in the lungs of cystic fibrosis patients, biofilms are a serious health concern and difficult to eradicate. One of the key building blocks involved in biofilm formation are polymeric sugar compounds that are secreted by the bacteria. Our work focuses on the biopolymer poly-β(1,6)-N-acetyl-D-glucosamine (PNAG), which is produced by numerous pathogenic organisms. Deacetylation of PNAG by the N-terminal domain of PgaB is a critical step in polymer maturation and is required for the formation of robust biofilms. Herein, we show that the C-terminal domain of PgaB is a glycoside hydrolase active on partially deacetylated PNAG, and that the enzyme disrupts PNAG-dependent biofilms and potentiates killing by antibiotics. Only deacetylated PNAG could be cleaved, suggesting that PgaB deacetylates and hydrolyses the polymer in sequential order. Analyzing the chemical structure of the cleaved dPNAG fragments revealed a distinct motif of sugar units. Structural and functional studies identify key amino acids positioned in an elongated polymer-binding groove that potentially recognize the sugar motif during cleavage. Our study provides further insight into the mechanism of periplasmic PNAG modification, and suggests PgaB could be utilized as a therapeutic agent to eliminate biofilms.
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Affiliation(s)
- Dustin J Little
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Roland Pfoh
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - François Le Mauff
- Departments of Medicine and of Microbiology and Immunology, McGill University, Montréal, QC, Canada.,Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montréal, QC, Canada
| | - Natalie C Bamford
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Christina Notte
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Perrin Baker
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Manita Guragain
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, United States of America.,Department of Microbial Infection and Immunity, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
| | - Howard Robinson
- Photon Sciences Division, Brookhaven National Laboratory, Upton, NY, United States of America
| | - Gerald B Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Mark Nitz
- Department of Chemistry, University of Toronto, Toronto, ON, Canada
| | - Rajendar Deora
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, United States of America.,Department of Microbial Infection and Immunity, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
| | - Donald C Sheppard
- Departments of Medicine and of Microbiology and Immunology, McGill University, Montréal, QC, Canada.,Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montréal, QC, Canada
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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Blanchette KA, Wenke JC. Current therapies in treatment and prevention of fracture wound biofilms: why a multifaceted approach is essential for resolving persistent infections. J Bone Jt Infect 2018; 3:50-67. [PMID: 29761067 PMCID: PMC5949568 DOI: 10.7150/jbji.23423] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/16/2018] [Indexed: 12/13/2022] Open
Abstract
Traumatic orthopedic injuries, particularly extremity wounds, are a significant cause of morbidity. Despite prophylactic antibiotic treatment and surgical intervention, persistent infectious complications can and do occur. Persistent bacterial infections are often caused by biofilms, communities of antibiotic tolerant bacteria encased within a matrix. The structural and metabolic differences in this mode of growth make treatment difficult. Herein, we describe both established and novel, experimental treatments targeted at various stages of wound healing that are specifically aimed at reducing and eliminating biofilm bacteria. Importantly, the highly tolerant nature of these bacterial communities suggests that most singular approaches could be circumvented and a multifaceted, combinatorial approach will be the most effective strategy for treating these complicated infections.
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Affiliation(s)
| | - Joseph C Wenke
- US Army Institute of Surgical Research, Ft Sam Houston, TX
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The Bordetella Bps Polysaccharide Is Required for Biofilm Formation and Enhances Survival in the Lower Respiratory Tract of Swine. Infect Immun 2017; 85:IAI.00261-17. [PMID: 28559403 DOI: 10.1128/iai.00261-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 05/18/2017] [Indexed: 12/21/2022] Open
Abstract
Bordetella bronchiseptica is pervasive in swine populations and plays multiple roles in respiratory disease. Additionally, B. bronchiseptica is capable of establishing long-term or chronic infections in swine. Bacterial biofilms are increasingly recognized as important contributors to chronic bacterial infections. Recently the polysaccharide locus bpsABCD has been demonstrated to serve a critical role in the development of mature biofilms formed by the sequenced laboratory strain of B. bronchiseptica We hypothesized that swine isolates would also have the ability to form mature biofilms and the bpsABCD locus would serve a key role in this process. A mutant containing an in-frame deletion of the bpsABCD structural genes was constructed in a wild-type swine isolate and found to be negative for poly-N-acetylglucosamine (PNAG)-like material by immunoblot assay. Further, the bpsABCD locus was found to be required for the development and maintenance of the three-dimensional structures under continuous-flow conditions. To investigate the contribution of the bpsABCD locus to the pathogenesis of B. bronchiseptica in swine, the KM22Δbps mutant was compared to the wild-type swine isolate for the ability to colonize and cause disease in pigs. The bpsABCD locus was found to not be required for persistence in the upper respiratory tract of swine. Additionally, the bpsABCD locus did not affect the development of anti-Bordetella humoral immunity, did not contribute to disease severity, and did not mediate protection from complement-mediated killing. However, the bpsABCD locus was found to enhance survival in the lower respiratory tract of swine.
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Zmantar T, Ben Slama R, Fdhila K, Kouidhi B, Bakhrouf A, Chaieb K. Modulation of drug resistance and biofilm formation of Staphylococcus aureus isolated from the oral cavity of Tunisian children. Braz J Infect Dis 2016; 21:27-34. [PMID: 27916605 PMCID: PMC9425528 DOI: 10.1016/j.bjid.2016.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 09/12/2016] [Accepted: 10/26/2016] [Indexed: 11/30/2022] Open
Abstract
Objectives This study aims to investigate the antimicrobial and the anti-biofilm activities of Lactobacillus plantarum extract (LPE) against a panel of oral Staphylococcus aureus (n = 9) and S. aureus ATCC 25923. The in vitro ability of LPE to modulate bacterial resistance to tetracycline, benzalchonium chloride, and chlorhexidine were tested also. Methods The minimum inhibitory concentrations (MICs) and the minimal bactericidal concentrations of Lactobacillus plantarum extract, tetracycline, benzalchonium chloride and clohrhexidine were determined in absence and in presence of a sub-MIC doses of LPE (1/2 MIC). In addition, the LPE potential to inhibit biofilm formation was assessed by microtiter plate and atomic force microscopy assays. Statistical analysis was performed on SPSS v. 17.0 software using Friedman test and Wilcoxon signed ranks test. These tests were used to assess inter-group difference (p < 0.05). Results Our results revealed that LPE exhibited a significant antimicrobial and anti-biofilm activities against the tested strains. A synergistic effect of LPEs and drug susceptibility was observed with a 2–8-fold reduction. Conclusion LPE may be considered to have resistance-modifying activity. A more detailed investigation is necessary to determine the active compound responsible for therapeutic and disinfectant modulation.
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Affiliation(s)
- Tarek Zmantar
- Faculty of Pharmacy, Laboratory of Analysis, Treatment and Valorization of Pollutants of the Environment and Products, Monastir University, Tunisia
| | - Rihab Ben Slama
- Faculty of Pharmacy, Laboratory of Analysis, Treatment and Valorization of Pollutants of the Environment and Products, Monastir University, Tunisia
| | - Kais Fdhila
- Faculty of Pharmacy, Laboratory of Analysis, Treatment and Valorization of Pollutants of the Environment and Products, Monastir University, Tunisia
| | - Bochra Kouidhi
- College of Applied Medical Sciences, Medical Laboratory Technology Department, Yanbu al Bahr, Taibah University, Al Madinah Al Monawarah, Saudi Arabia
| | - Amina Bakhrouf
- Faculty of Pharmacy, Laboratory of Analysis, Treatment and Valorization of Pollutants of the Environment and Products, Monastir University, Tunisia
| | - Kamel Chaieb
- College of Sciences, Biology Department, Yanbu al Bahr, Taibah University, Al Madinah Al Monawarah, Saudi Arabia.
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32
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Schwartbeck B, Birtel J, Treffon J, Langhanki L, Mellmann A, Kale D, Kahl J, Hirschhausen N, Neumann C, Lee JC, Götz F, Rohde H, Henke H, Küster P, Peters G, Kahl BC. Dynamic in vivo mutations within the ica operon during persistence of Staphylococcus aureus in the airways of cystic fibrosis patients. PLoS Pathog 2016; 12:e1006024. [PMID: 27902784 PMCID: PMC5130281 DOI: 10.1371/journal.ppat.1006024] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/25/2016] [Indexed: 11/18/2022] Open
Abstract
Cystic fibrosis (CF) is associated with chronic bacterial airway infections leading to lung insufficiency and decreased life expectancy. Staphylococcus aureus is one of the most prevalent pathogens isolated from the airways of CF patients. Mucoid colony morphology has been described for Pseudomonas aeruginosa, the most common pathogen in CF, but not for S. aureus. From the airways of 8 of 313 CF patients (2.5%) mucoid S. aureus isolates (n = 115) were cultured with a mean persistence of 29 months (range 1 month, 126 months). In contrast to non-mucoid S. aureus, mucoid isolates were strong biofilm formers. The upstream region of the ica operon, which encodes the proteins responsible for the synthesis of the polysaccharide intercellular adhesin (PIA), of mucoid isolates was sequenced. Spa-types of mucoid and non-mucoid strains were identical, but differed between patients. Mucoid isolates carried a 5 bp deletion in the intergenic region between icaR and icaA. During long-term persistence, from two patients subsequent non-mucoid isolates (n = 12) with 5 bp deletions were cultured, which did not produce biofilm. Sequencing of the entire ica operon identified compensatory mutations in various ica-genes including icaA (n = 7), icaD (n = 3) and icaC (n = 2). Six sequential isolates of each of these two patients with non-mucoid and mucoid phenotypes were subjected to whole genome sequencing revealing a very close relationship of the individual patient’s isolates. Transformation of strains with vectors expressing the respective wild-type genes restored mucoidy. In contrast to the non-mucoid phenotype, mucoid strains were protected against neutrophilic killing and survived better under starvation conditions. In conclusion, the special conditions present in CF airways seem to facilitate ongoing mutations in the ica operon during S. aureus persistence. Staphylococcus aureus is one of the most common pathogens isolated from the airways of cystic fibrosis (CF) patients. In this study, we identified unusual mucoid S. aureus isolates in 8 of 313 (2.5%) CF patients. All mucoid isolates carried a 5 bp deletion upstream of the ica operon, which resulted in increased expression of PIA/PNAG biofilm. In three patients, mucoid isolates were recovered for extended periods up to 126 months. Surprisingly, later sequential non-mucoid isolates (n = 12) of two patients also carried the 5 bp deletion. Sequencing of the entire ica operon identified compensatory mutations in different ica genes (icaA, icaD, icaC) in these isolates. A close relationship of these isolates and of the first mucoid and closest non-mucoid isolate without 5 bp deletion were confirmed by whole genome sequencing. Transformation with expression vectors with respective wild-type genes restored mucoidy. Mucoid isolates were protected against neutrophil killing and survived better under starvation conditions. In conclusion, the special conditions present in CF airways seem to facilitate ongoing mutations in the ica operon during persistence of S. aureus.
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Affiliation(s)
| | - Johannes Birtel
- Institute of Medical Microbiology, University Clinics Münster, Germany
- Channing Laboratory, Brigham and Women’s Hospital, Harvard Medical School Boston, United States of America
| | - Janina Treffon
- Institute of Medical Microbiology, University Clinics Münster, Germany
| | - Lars Langhanki
- Institute for Hygiene, University Clinics Münster, Germany
| | | | - Devika Kale
- Institute of Medical Microbiology, University Clinics Münster, Germany
| | - Janina Kahl
- Institute of Medical Microbiology, University Clinics Münster, Germany
| | - Nina Hirschhausen
- Institute of Medical Microbiology, University Clinics Münster, Germany
| | - Claudia Neumann
- Institute of Medical Microbiology, University Clinics Münster, Germany
| | - Jean C. Lee
- Channing Laboratory, Brigham and Women’s Hospital, Harvard Medical School Boston, United States of America
| | - Friedrich Götz
- Department of Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Hanae Henke
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Peter Küster
- Pediatric Department Clemenshospital Münster, Münster, Germany
| | - Georg Peters
- Institute of Medical Microbiology, University Clinics Münster, Germany
| | - Barbara C. Kahl
- Institute of Medical Microbiology, University Clinics Münster, Germany
- * E-mail:
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Crosby HA, Kwiecinski J, Horswill AR. Staphylococcus aureus Aggregation and Coagulation Mechanisms, and Their Function in Host-Pathogen Interactions. ADVANCES IN APPLIED MICROBIOLOGY 2016; 96:1-41. [PMID: 27565579 DOI: 10.1016/bs.aambs.2016.07.018] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human commensal bacterium Staphylococcus aureus can cause a wide range of infections ranging from skin and soft tissue infections to invasive diseases like septicemia, endocarditis, and pneumonia. Muticellular organization almost certainly contributes to S. aureus pathogenesis mechanisms. While there has been considerable focus on biofilm formation and its role in colonizing prosthetic joints and indwelling devices, less attention has been paid to nonsurface-attached group behavior like aggregation and clumping. S. aureus is unique in its ability to coagulate blood, and it also produces multiple fibrinogen-binding proteins that facilitate clumping. Formation of clumps, which are large, tightly packed groups of cells held together by fibrin(ogen), has been demonstrated to be important for S. aureus virulence and immune evasion. Clumps of cells are able to avoid detection by the host's immune system due to a fibrin(ogen) coat that acts as a shield, and the size of the clumps facilitates evasion of phagocytosis. In addition, clumping could be an important early step in establishing infections that involve tight clusters of cells embedded in host matrix proteins, such as soft tissue abscesses and endocarditis. In this review, we discuss clumping mechanisms and regulation, as well as what is known about how clumping contributes to immune evasion.
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Affiliation(s)
- H A Crosby
- University of Iowa, Iowa City, IA, United States
| | - J Kwiecinski
- University of Iowa, Iowa City, IA, United States
| | - A R Horswill
- University of Iowa, Iowa City, IA, United States
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Skurnik D, Cywes-Bentley C, Pier GB. The exceptionally broad-based potential of active and passive vaccination targeting the conserved microbial surface polysaccharide PNAG. Expert Rev Vaccines 2016; 15:1041-53. [PMID: 26918288 PMCID: PMC4985264 DOI: 10.1586/14760584.2016.1159135] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/24/2016] [Indexed: 11/08/2022]
Abstract
A challenging component of vaccine development is the large serologic diversity of protective antigens. Remarkably, there is a conserved surface/capsular polysaccharide, one of the most effective vaccine targets, expressed by a large number of bacterial, fungal and eukaryotic pathogens: poly-N-acetyl glucosamine (PNAG). Natural antibodies to PNAG are poorly effective at mediating in vitro microbial killing or in vivo protection. Removing most of the acetate substituents to produce a deacetylated glycoform, or using synthetic oligosaccharides of poly-β-1-6-linked glucosamine conjugated to carrier proteins, results in vaccines that elicit high levels of broad-based immunity. A fully human monoclonal antibody is highly active in laboratory and preclinical studies and has been successfully tested in a phase-I setting. Both the synthetic oligosaccharide conjugate vaccine and MAb will be further tested in humans starting in 2016; but, even if effective against only a fraction of the PNAG-producing pathogens, a major advance in vaccine-preventable diseases will occur.
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Affiliation(s)
- David Skurnik
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
| | - Colette Cywes-Bentley
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
| | - Gerald B. Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
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35
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Guillard T, Pons S, Roux D, Pier GB, Skurnik D. Antibiotic resistance and virulence: Understanding the link and its consequences for prophylaxis and therapy. Bioessays 2016; 38:682-93. [PMID: 27248008 DOI: 10.1002/bies.201500180] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
"Antibiotic resistance is usually associated with a fitness cost" is frequently accepted as common knowledge in the field of infectious diseases. However, with the advances in high-throughput DNA sequencing that allows for a comprehensive analysis of bacterial pathogenesis at the genome scale, including antibiotic resistance genes, it appears that this paradigm might not be as solid as previously thought. Recent studies indicate that antibiotic resistance is able to enhance bacterial fitness in vivo with a concomitant increase in virulence during infections. As a consequence, strategies to minimize antibiotic resistance turn out to be not as simple as initially believed. Indeed, decreased antibiotic use may not be sufficient to let susceptible strains outcompete the resistant ones. Here, we put in perspective these findings and review alternative approaches, such as preventive and therapeutic anti-bacterial immunotherapies that have the potential to by-pass the classic antibiotics.
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Affiliation(s)
- Thomas Guillard
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Laboratoire de Bactériologie-Virologie-Hygiène hospitalière, Hôpital Robert Debré - CHU de Reims, UFR de Médecine, Université de Reims Champagne-Ardenne, Reims, France
| | - Stéphanie Pons
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Damien Roux
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,INSERM, IAME, UMR 1137, Paris, France.,Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.,AP-HP, Hôpital Louis Mourier, Service de Réanimation Médico-Chirurgicale, Colombes, France
| | - Gerald B Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - David Skurnik
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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36
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Abstract
Microbes produce a biofilm matrix consisting of proteins, extracellular DNA, and polysaccharides that is integral in the formation of bacterial communities. Historical studies of polysaccharides revealed that their overproduction often alters the colony morphology and can be diagnostic in identifying certain species. The polysaccharide component of the matrix can provide many diverse benefits to the cells in the biofilm, including adhesion, protection, and structure. Aggregative polysaccharides act as molecular glue, allowing the bacterial cells to adhere to each other as well as surfaces. Adhesion facilitates the colonization of both biotic and abiotic surfaces by allowing the bacteria to resist physical stresses imposed by fluid movement that could separate the cells from a nutrient source. Polysaccharides can also provide protection from a wide range of stresses, such as desiccation, immune effectors, and predators such as phagocytic cells and amoebae. Finally, polysaccharides can provide structure to biofilms, allowing stratification of the bacterial community and establishing gradients of nutrients and waste products. This can be advantageous for the bacteria by establishing a heterogeneous population that is prepared to endure stresses created by the rapidly changing environments that many bacteria encounter. The diverse range of polysaccharide structures, properties, and roles highlight the importance of this matrix constituent to the successful adaptation of bacteria to nearly every niche. Here, we present an overview of the current knowledge regarding the diversity and benefits that polysaccharide production provides to bacterial communities within biofilms.
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37
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Gogoi-Tiwari J, Williams V, Waryah CB, Mathavan S, Tiwari HK, Costantino P, Mukkur T. Intramammary Immunization of Pregnant Mice with Staphylococcal Protein A Reduces the Post-Challenge Mammary Gland Bacterial Load but Not Pathology. PLoS One 2016; 11:e0148383. [PMID: 26862761 PMCID: PMC4749186 DOI: 10.1371/journal.pone.0148383] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 01/18/2016] [Indexed: 11/25/2022] Open
Abstract
Protein A, encoded by the spa gene, is one of the major immune evading MSCRAMM of S. aureus, demonstrated to be prevalent in a significant percentage of clinical bovine mastitis isolates in Australia. Given its’ reported significance in biofilm formation and the superior performance of S. aureus biofilm versus planktonic vaccine in the mouse mastitis model, it was of interest to determine the immunogenicity and protective potential of Protein A as a potential vaccine candidate against bovine mastitis using the mouse mastitis model. Pregnant Balb/c mice were immunised with Protein A emulsified in an alum-based adjuvant by subcutaneous (s/c) or intramammary (i/mam) routes. While humoral immune response of mice post-immunization were determined using indirect ELISA, cell-mediated immune response was assessed by estimation of interferon-gamma (IFN-γ) produced by protein A-stimulated splenocyte supernatants. Protective potential of Protein A against experimental mastitis was determined by challenge of immunized versus sham-vaccinated mice by i/mam route, based upon manifestation of clinical symptoms, total bacterial load and histopathological damage to mammary glands. Significantly (p<0.05) higher levels of IgG1 isotype were produced in mice immunized by the s/c route. In contrast, significantly higher levels of the antibody isotype IgG2a were produced in mice immunized by the i/mam route (p<0.05). There was significant reduction (p<0.05) in bacterial loads of the mammary glands of mice immunized by Protein A regardless of the route of immunization, with medium level of clinical symptoms observed up to day 3 post-challenge. However, Protein A vaccine failed to protect immunized mice post-challenge with biofilm producing encapsulated S. aureus via i/mam route, regardless of the route of immunization, as measured by the level of mammary tissue damage. It was concluded that, Protein A in its’ native state was apparently not a suitable candidate for inclusion in a cell-free vaccine formulation against mastitis.
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Affiliation(s)
- Jully Gogoi-Tiwari
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, 6102, Australia
- College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Selesih, Aizawl, Mizoram, 796014, India
| | - Vincent Williams
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, 6102, Australia
| | - Charlene Babra Waryah
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, 6102, Australia
- Department of Medicine and Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY, 10461, United States of America
| | - Sangeetha Mathavan
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, 6102, Australia
| | - Harish Kumar Tiwari
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Perth, Western Australia, 6150, Australia
| | - Paul Costantino
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, 6102, Australia
| | - Trilochan Mukkur
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, 6102, Australia
- * E-mail:
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38
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Kim BR, Bae YM, Lee SY. Effect of Environmental Conditions on Biofilm Formation and Related Characteristics of Staphylococcus Aureus. J Food Saf 2016. [DOI: 10.1111/jfs.12263] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bo-Ram Kim
- Department of Food Science and Technology; Chung-Ang University; 72-1 Nae-ri Daedeok-myeon, Anseong-si Gyeonggi-do 456-756 South Korea
| | - Young-Min Bae
- Department of Food Science and Technology; Chung-Ang University; 72-1 Nae-ri Daedeok-myeon, Anseong-si Gyeonggi-do 456-756 South Korea
| | - Sun-Young Lee
- Department of Food Science and Technology; Chung-Ang University; 72-1 Nae-ri Daedeok-myeon, Anseong-si Gyeonggi-do 456-756 South Korea
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39
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Giguère D. Surface polysaccharides from Acinetobacter baumannii : Structures and syntheses. Carbohydr Res 2015; 418:29-43. [DOI: 10.1016/j.carres.2015.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 09/30/2015] [Accepted: 10/03/2015] [Indexed: 12/31/2022]
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40
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Abdulamir AS, Jassim SAA, Hafidh RR, Bakar FA. The potential of bacteriophage cocktail in eliminating Methicillin-resistant Staphylococcus aureus biofilms in terms of different extracellular matrices expressed by PIA, ciaA-D and FnBPA genes. Ann Clin Microbiol Antimicrob 2015; 14:49. [PMID: 26558683 PMCID: PMC4642773 DOI: 10.1186/s12941-015-0106-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 10/05/2015] [Indexed: 11/26/2022] Open
Abstract
Background This study assessed novel approach of using highly lytic phages against methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) biofilms with and without biofilm extracellular matrix- disrupting chemical. Method The resultant phage-based control was assessed in relation to the type of biofilm extracellular matrix namely, polysaccharide intercellular adhesion (PIA) or proteinacious fibronectin-binding protein A (FnBPA). The biofilms were formed in vitro by 24 h incubation of bacteria in 96 wells microtiter plates at room temperature. The formed biofilms were assessed by tissue culture plate (TCP). Moreover, the nature of the biofilm was assessed by scanning electron microscopy (SEM) and PCR assay for detecting PIA genes, ciaA-D and FnBPA genes. Results this study showed that applied phages with 0.08 % benezenthonium chloride, for PIA biofilms, and 0.06 % ethanol, for proteinacious FnBPA biofilms, exerted 100 % eradication for MSSA biofilms and about 78 % of MRSA biofilms. The phage-based control of biofilms with chemical adjuvant showed significantly higher efficiency than that without adjuvant (P < 0.05). Moreover, FnBPA biofilms were more common in MRSA than in MSSA while PIA biofilms were more common in MSSA than in MRSA. And the most resistant type of biofilms to phage-based control was FnBPA in MRSA where 50 % of biofilms were reduced but not eradicated completely. Conclusions It is concluded that PIA-disturbing agent and protein denaturing alcohol can increase the efficiency of attacking phages in accessing host cell walls and lysing them which in turn lead to much more efficient MRSA and MSSA biofilm treatment and prevention.
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Affiliation(s)
- Ahmed Sahib Abdulamir
- Microbiology Department, College of Medicine, Alnahrain University, 14222, Baghdad, Iraq.
| | - Sabah A A Jassim
- Applied Bio Research Inc., Windsor, Canada. .,Environmental Engineering, University of Windsor, Windsor, Canada.
| | - Rand R Hafidh
- Microbiology Department, College of Medicine, Baghdad University, Baghdad, Iraq.
| | - Fatimah Abu Bakar
- Faculty of Food Science, University Putra Malaysia, Serdang, 43400, Selangor, Malaysia.
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Little DJ, Milek S, Bamford NC, Ganguly T, DiFrancesco BR, Nitz M, Deora R, Howell PL. The protein BpsB is a poly-β-1,6-N-acetyl-D-glucosamine deacetylase required for biofilm formation in Bordetella bronchiseptica. J Biol Chem 2015. [PMID: 26203190 DOI: 10.1074/jbc.m115.672469] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Bordetella pertussis and Bordetella bronchiseptica are the causative agents of whooping cough in humans and a variety of respiratory diseases in animals, respectively. Bordetella species produce an exopolysaccharide, known as the Bordetella polysaccharide (Bps), which is encoded by the bpsABCD operon. Bps is required for Bordetella biofilm formation, colonization of the respiratory tract, and confers protection from complement-mediated killing. In this report, we have investigated the role of BpsB in the biosynthesis of Bps and biofilm formation by B. bronchiseptica. BpsB is a two-domain protein that localizes to the periplasm and outer membrane. BpsB displays metal- and length-dependent deacetylation on poly-β-1,6-N-acetyl-d-glucosamine (PNAG) oligomers, supporting previous immunogenic data that suggests Bps is a PNAG polymer. BpsB can use a variety of divalent metal cations for deacetylase activity and showed highest activity in the presence of Ni(2+) and Co(2+). The structure of the BpsB deacetylase domain is similar to the PNAG deacetylases PgaB and IcaB and contains the same circularly permuted family four carbohydrate esterase motifs. Unlike PgaB from Escherichia coli, BpsB is not required for polymer export and has unique structural differences that allow the N-terminal deacetylase domain to be active when purified in isolation from the C-terminal domain. Our enzymatic characterizations highlight the importance of conserved active site residues in PNAG deacetylation and demonstrate that the C-terminal domain is required for maximal deacetylation of longer PNAG oligomers. Furthermore, we show that BpsB is critical for the formation and complex architecture of B. bronchiseptica biofilms.
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Affiliation(s)
- Dustin J Little
- From the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Sonja Milek
- the Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, and
| | - Natalie C Bamford
- From the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Tridib Ganguly
- the Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, and
| | | | - Mark Nitz
- the Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Rajendar Deora
- the Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, and
| | - P Lynne Howell
- From the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada,
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Roux D, Cywes-Bentley C, Zhang YF, Pons S, Konkol M, Kearns DB, Little DJ, Howell PL, Skurnik D, Pier GB. Identification of Poly-N-acetylglucosamine as a Major Polysaccharide Component of the Bacillus subtilis Biofilm Matrix. J Biol Chem 2015; 290:19261-72. [PMID: 26078454 DOI: 10.1074/jbc.m115.648709] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 12/22/2022] Open
Abstract
Bacillus subtilis is intensively studied as a model organism for the development of bacterial biofilms or pellicles. A key component is currently undefined exopolysaccharides produced from proteins encoded by genes within the eps locus. Within this locus are four genes, epsHIJK, known to be essential for pellicle formation. We show they encode proteins synthesizing the broadly expressed microbial carbohydrate poly-N-acetylglucosamine (PNAG). PNAG was present in both pellicle and planktonic wild-type B. subtilis cells and in strains with deletions in the epsA-G and -L-O genes but not in strains deleted for epsH-K. Cloning of the B. subtilis epsH-K genes into Escherichia coli with in-frame deletions in the PNAG biosynthetic genes pgaA-D, respectively, restored PNAG production in E. coli. Cloning the entire B. subtilis epsHIJK locus into pga-deleted E. coli, Klebsiella pneumoniae, or alginate-negative Pseudomonas aeruginosa restored or conferred PNAG production. Bioinformatic and structural predictions of the EpsHIJK proteins suggest EpsH and EpsJ are glycosyltransferases (GT) with a GT-A fold; EpsI is a GT with a GT-B fold, and EpsK is an α-helical membrane transporter. B. subtilis, E. coli, and pga-deleted E. coli carrying the epsHIJK genes on a plasmid were all susceptible to opsonic killing by antibodies to PNAG. The immunochemical and genetic data identify the genes and proteins used by B. subtilis to produce PNAG as a significant carbohydrate factor essential for pellicle formation.
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Affiliation(s)
- Damien Roux
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
| | - Colette Cywes-Bentley
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
| | - Yi-Fan Zhang
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and Harvard School of Dental Medicine, Boston, Massachusetts 02115
| | - Stephanie Pons
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
| | - Melissa Konkol
- the Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Daniel B Kearns
- the Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Dustin J Little
- the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - P Lynne Howell
- the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - David Skurnik
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
| | - Gerald B Pier
- From the Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and
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43
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Merghni A, Ben Nejma M, Helali I, Hentati H, Bongiovanni A, Lafont F, Aouni M, Mastouri M. Assessment of adhesion, invasion and cytotoxicity potential of oral Staphylococcus aureus strains. Microb Pathog 2015; 86:1-9. [PMID: 26055540 DOI: 10.1016/j.micpath.2015.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/30/2015] [Accepted: 05/04/2015] [Indexed: 10/23/2022]
Abstract
The oral cavity is regarded as a relevant site for Staphylococcus aureus colonization. However, characterization of virulence mechanisms of oral S. aureus remains to be uncovered. In this study, twenty one S. aureus strains isolated from the oral cavity of Tunisian patients were screened for adherence, invasion and cytotoxicity against HeLa cells. In addition, the presence of adhesins (icaA, icaD, can, fnbA and fnbB) and α-hemolysin (hla) genes in each strain was achieved by polymerase chain reaction (PCR). Our finding revealed that oral S. aureus strains were able to adhere and invade epithelial cells, with variable degrees (P < 0.05). Moreover they exhibited either low (23.8%) or moderate (76.2%) cytotoxic effects. In addition 76.2% of strains were icaA and icaD positive and 90.5% harbor both the fnbA and the fnbB gene. While the cna gene was detected in 12 strains (57.2%). Furthermore, the hla gene encoding the α-toxin was found in 52.4% of the isolates. All these virulence factors give to S. aureus the right qualities to become a redoubtable pathogen associated to oral infections.
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Affiliation(s)
- Abderrahmen Merghni
- Laboratoire des Maladies Transmissible et Substances Biologiquement Actives, LR99ES27, Faculté de Pharmacie de Monastir, Université de Monastir, Tunisia.
| | - Mouna Ben Nejma
- Laboratoire des Maladies Transmissible et Substances Biologiquement Actives, LR99ES27, Faculté de Pharmacie de Monastir, Université de Monastir, Tunisia
| | - Imen Helali
- Laboratoire des Maladies Transmissible et Substances Biologiquement Actives, LR99ES27, Faculté de Pharmacie de Monastir, Université de Monastir, Tunisia
| | - Hajer Hentati
- Service de Médecine et chirurgie buccales, Clinique universitaire de médecine dentaire, Monastir, Tunisia
| | | | - Frank Lafont
- BioImaging Center Lille-Nord de France, Lille, France; Cellular Microbiology and Physics of Infection Group, Center for Infection and Immunity of Lille-CNRS UMR8204, INSERM U1019, Institut Pasteur de Lille, Lille University, France
| | - Mahjoub Aouni
- Laboratoire des Maladies Transmissible et Substances Biologiquement Actives, LR99ES27, Faculté de Pharmacie de Monastir, Université de Monastir, Tunisia
| | - Maha Mastouri
- Laboratoire des Maladies Transmissible et Substances Biologiquement Actives, LR99ES27, Faculté de Pharmacie de Monastir, Université de Monastir, Tunisia; Laboratoire de Microbiologie, CHU Fatouma Bourguiba de Monastir, Tunisia
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Whitfield GB, Marmont LS, Howell PL. Enzymatic modifications of exopolysaccharides enhance bacterial persistence. Front Microbiol 2015; 6:471. [PMID: 26029200 PMCID: PMC4432689 DOI: 10.3389/fmicb.2015.00471] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/29/2015] [Indexed: 12/25/2022] Open
Abstract
Biofilms are surface-attached communities of bacterial cells embedded in a self-produced matrix that are found ubiquitously in nature. The biofilm matrix is composed of various extracellular polymeric substances, which confer advantages to the encapsulated bacteria by protecting them from eradication. The matrix composition varies between species and is dependent on the environmental niche that the bacteria inhabit. Exopolysaccharides (EPS) play a variety of important roles in biofilm formation in numerous bacterial species. The ability of bacteria to thrive in a broad range of environmental settings is reflected in part by the structural diversity of the EPS produced both within individual bacterial strains as well as by different species. This variability is achieved through polymerization of distinct sugar moieties into homo- or hetero-polymers, as well as post-polymerization modification of the polysaccharide. Specific enzymes that are unique to the production of each polymer can transfer or remove non-carbohydrate moieties, or in other cases, epimerize the sugar units. These modifications alter the physicochemical properties of the polymer, which in turn can affect bacterial pathogenicity, virulence, and environmental adaptability. Herein, we review the diversity of modifications that the EPS alginate, the Pel polysaccharide, Vibrio polysaccharide, cepacian, glycosaminoglycans, and poly-N-acetyl-glucosamine undergo during biosynthesis. These are EPS produced by human pathogenic bacteria for which studies have begun to unravel the effect modifications have on their physicochemical and biological properties. The biological advantages these polymer modifications confer to the bacteria that produce them will be discussed. The expanding list of identified modifications will allow future efforts to focus on linking these modifications to specific biosynthetic genes and biofilm phenotypes.
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Affiliation(s)
- Gregory B Whitfield
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children Toronto, ON, Canada ; Department of Biochemistry, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Lindsey S Marmont
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children Toronto, ON, Canada ; Department of Biochemistry, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - P Lynne Howell
- Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children Toronto, ON, Canada ; Department of Biochemistry, Faculty of Medicine, University of Toronto Toronto, ON, Canada
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Causes of mortality of captive Arabian gazelles (Gazella Arabica) at King Khalid Wildlife Research Centre, Kingdom of Saudi Arabia, from 1988 to 2011. J Zoo Wildl Med 2015; 46:1-8. [PMID: 25831570 DOI: 10.1638/2013-0012r2.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We investigated the causes of mortality of the Arabian gazelle (Gazella arabica) based on the necropsy records of 1218 captive animals at King Khalid Wildlife Research Centre, Saudi Arabia, from 1988 to 2011. The largest number of deaths was attributed to trauma (391, 32.1%). Trauma was subdivided into the following three categories: collisions with fences (144, 11.8%); predator activity (91, 7.5%), and exhibit-mate aggression (156, 12.8%). Respiratory infection was another important cause of mortality, accounting for 186 (15.3%) deaths. Respiratory infection was more prevalent during the winter season (November to March). Other causes of death included gastrointestinal diseases, such as clostridiosis and salmonellosis (108, 8.9%). Maternal neglect (104, 8.5%), chronic renal fibrosis (34, 2.8%), and stress-related pathologies (35, 2.9%), in particular, capture myopathy, were also important causes of mortality. Here, the importance of these findings for improvement of the captive management of this vulnerable Arabian species is discussed, and for the first time, salmonellosis in Arabian gazelles is reported.
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46
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Gogoi-Tiwari J, Williams V, Waryah CB, Eto KY, Tau M, Costantino P, Tiwari HK, Mukkur T. Comparative studies of the immunogenicity and protective potential of biofilm vs planktonic Staphylococcus aureus vaccine against bovine mastitis using non-invasive mouse mastitis as a model system. BIOFOULING 2015; 31:543-554. [PMID: 26293793 DOI: 10.1080/08927014.2015.1074681] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study was undertaken to compare the immunogenicity and protective potential of biofilm vs planktonic Staphylococcus aureus vaccine for the prevention of mastitis using the mouse as a model system. Mice immunized with formalin-killed whole cell vaccine of S. aureus residing in a biofilm when delivered via an intramammary route produced a cell mediated immune response. Mice immunized with this biofilm vaccine showed significant reductions in colonization by S. aureus in mammary glands, severity of clinical symptoms and tissue damage in mammary glands in comparison with the mice immunized with formalin-killed whole cells of planktonic S. aureus. The planktonic vaccine administered by a subcutaneous route produced a significantly higher humoral immune response (IgG1 and IgG) than the biofilm vaccine. However, considering the host response, tissue damage, the clinical severity and colonization of S. aureus in mammary glands, the biofilm vaccine performed better in immunogenicity and protective potential when administered by the intramammary route.
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Affiliation(s)
- Jully Gogoi-Tiwari
- a Faculty of Health Sciences, School of Biomedical Sciences, Curtin Health Innovation Research Institute , Curtin University , Bentley, Perth , Australia
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Weidenmaier C, Lee JC. Structure and Function of Surface Polysaccharides of Staphylococcus aureus. Curr Top Microbiol Immunol 2015; 409:57-93. [PMID: 26728067 DOI: 10.1007/82_2015_5018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The major surface polysaccharides of Staphylococcus aureus include the capsular polysaccharide (CP), cell wall teichoic acid (WTA), and polysaccharide intercellular adhesin/poly-β(1-6)-N-acetylglucosamine (PIA/PNAG). These glycopolymers are important components of the staphylococcal cell envelope, but none of them is essential to S. aureus viability and growth in vitro. The overall biosynthetic pathways of CP, WTA, and PIA/PNAG have been elucidated, and the functions of most of the biosynthetic enzymes have been demonstrated. Because S. aureus CP and WTA (but not PIA/PNAG) utilize a common cell membrane lipid carrier (undecaprenyl-phosphate) that is shared by the peptidoglycan biosynthesis pathway, there is evidence that these processes are highly integrated and temporally regulated. Regulatory elements that control glycopolymer biosynthesis have been described, but the cross talk that orchestrates the biosynthetic pathways of these three polysaccharides remains largely elusive. CP, WTA, and PIA/PNAG each play distinct roles in S. aureus colonization and the pathogenesis of staphylococcal infection. However, they each promote bacterial evasion of the host immune defences, and WTA is being explored as a target for antimicrobial therapeutics. All the three glycopolymers are viable targets for immunotherapy, and each (conjugated to a carrier protein) is under evaluation for inclusion in a multivalent S. aureus vaccine. Future research findings that increase our understanding of these surface polysaccharides, how the bacterial cell regulates their expression, and their biological functions will likely reveal new approaches to controlling this important bacterial pathogen.
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Affiliation(s)
- Christopher Weidenmaier
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen and German Center for Infection Research, Tübingen, Germany
| | - Jean C Lee
- Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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The role of pgaC in Klebsiella pneumoniae virulence and biofilm formation. Microb Pathog 2014; 77:89-99. [PMID: 25450884 DOI: 10.1016/j.micpath.2014.11.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 09/19/2014] [Accepted: 11/05/2014] [Indexed: 11/23/2022]
Abstract
BACKGROUND Klebsiella pneumoniae has emerged as one of the major pathogens for community-acquired and nosocomial infections. A four-gene locus that had a high degree similarity with Escherichia coli pgaABCD and Yersinia pestis hmsHFRS was identified in K. pneumoniae genomes. The pgaABCD in E. coli encodes the envelope-spanning Pga machinery for the synthesis and secretion of poly-β-linked N-acetylglucosamine (PNAG). In a limited number of phylogenetically diverse bacteria, PNAG was demonstrated to mediate biofilm formation and had a role in the host-bacteria interactions. The presence of conserved pgaABCD locus among various K. pneumoniae strains suggested a putative requirement of PNAG for this bacterium. RESULTS In this study, an in-frame deletion of pgaC was generated in K. pneumoniae CG43 and named ΔpgaC. The loss of pgaC affected the production of PNAG and attenuated the enhancement of in vitro biofilm formation upon the addition of bile salts mixture. In mouse models, ΔpgaC exhibited a weakened ability to colonize the intestine, to disseminate extraintestinally, and to induce a systemic infection when compared to K. pneumoniae CG43. CONCLUSIONS Our study demonstrated that pgaC participated in the bile salts induced biofilm formation and was required for K. pneumoniae virulence in vivo.
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49
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Little DJ, Bamford NC, Pokrovskaya V, Robinson H, Nitz M, Howell PL. Structural basis for the De-N-acetylation of Poly-β-1,6-N-acetyl-D-glucosamine in Gram-positive bacteria. J Biol Chem 2014; 289:35907-17. [PMID: 25359777 DOI: 10.1074/jbc.m114.611400] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Exopolysaccharides are required for the development and integrity of biofilms produced by a wide variety of bacteria. In staphylococci, partial de-N-acetylation of the exopolysaccharide poly-β-1,6-N-acetyl-d-glucosamine (PNAG) by the extracellular protein IcaB is required for biofilm formation. To understand the molecular basis for PNAG de-N-acetylation, the structure of IcaB from Ammonifex degensii (IcaBAd) has been determined to 1.7 Å resolution. The structure of IcaBAd reveals a (β/α)7 barrel common to the family four carbohydrate esterases (CE4s) with the canonical motifs circularly permuted. The metal dependence of IcaBAd is similar to most CE4s showing the maximum rates of de-N-acetylation with Ni(2+), Co(2+), and Zn(2+). From docking studies with β-1,6-GlcNAc oligomers and structural comparison to PgaB from Escherichia coli, the Gram-negative homologue of IcaB, we identify Arg-45, Tyr-67, and Trp-180 as key residues for PNAG binding during catalysis. The absence of these residues in PgaB provides a rationale for the requirement of a C-terminal domain for efficient deacetylation of PNAG in Gram-negative species. Mutational analysis of conserved active site residues suggests that IcaB uses an altered catalytic mechanism in comparison to other characterized CE4 members. Furthermore, we identified a conserved surface-exposed hydrophobic loop found only in Gram-positive homologues of IcaB. Our data suggest that this loop is required for membrane association and likely anchors IcaB to the membrane during polysaccharide biosynthesis. The work presented herein will help guide the design of IcaB inhibitors to combat biofilm formation by staphylococci.
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Affiliation(s)
- Dustin J Little
- From the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada, Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Natalie C Bamford
- From the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada, Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Varvara Pokrovskaya
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada, and
| | - Howard Robinson
- Photon Sciences Division, Brookhaven National Laboratory, Upton, New York 11973-5000
| | - Mark Nitz
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada, and
| | - P Lynne Howell
- From the Program in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada, Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada,
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Abstract
The definition of the heterogeneous group of coagulase-negative staphylococci (CoNS) is still based on diagnostic procedures that fulfill the clinical need to differentiate between Staphylococcus aureus and those staphylococci classified historically as being less or nonpathogenic. Due to patient- and procedure-related changes, CoNS now represent one of the major nosocomial pathogens, with S. epidermidis and S. haemolyticus being the most significant species. They account substantially for foreign body-related infections and infections in preterm newborns. While S. saprophyticus has been associated with acute urethritis, S. lugdunensis has a unique status, in some aspects resembling S. aureus in causing infectious endocarditis. In addition to CoNS found as food-associated saprophytes, many other CoNS species colonize the skin and mucous membranes of humans and animals and are less frequently involved in clinically manifested infections. This blurred gradation in terms of pathogenicity is reflected by species- and strain-specific virulence factors and the development of different host-defending strategies. Clearly, CoNS possess fewer virulence properties than S. aureus, with a respectively different disease spectrum. In this regard, host susceptibility is much more important. Therapeutically, CoNS are challenging due to the large proportion of methicillin-resistant strains and increasing numbers of isolates with less susceptibility to glycopeptides.
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Affiliation(s)
- Karsten Becker
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Christine Heilmann
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Georg Peters
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
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