1
|
Mintz KP, Danforth DR, Ruiz T. The Trimeric Autotransporter Adhesin EmaA and Infective Endocarditis. Pathogens 2024; 13:99. [PMID: 38392837 PMCID: PMC10892112 DOI: 10.3390/pathogens13020099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024] Open
Abstract
Infective endocarditis (IE), a disease of the endocardial surface of the heart, is usually of bacterial origin and disproportionally affects individuals with underlying structural heart disease. Although IE is typically associated with Gram-positive bacteria, a minority of cases are caused by a group of Gram-negative species referred to as the HACEK group. These species, classically associated with the oral cavity, consist of bacteria from the genera Haemophilus (excluding Haemophilus influenzae), Aggregatibacter, Cardiobacterium, Eikenella, and Kingella. Aggregatibacter actinomycetemcomitans, a bacterium of the Pasteurellaceae family, is classically associated with Aggressive Periodontitis and is also concomitant with the chronic form of the disease. Bacterial colonization of the oral cavity serves as a reservoir for infection at distal body sites via hematological spreading. A. actinomycetemcomitans adheres to and causes disease at multiple physiologic niches using a diverse array of bacterial cell surface structures, which include both fimbrial and nonfimbrial adhesins. The nonfimbrial adhesin EmaA (extracellular matrix binding protein adhesin A), which displays sequence heterogeneity dependent on the serotype of the bacterium, has been identified as a virulence determinant in the initiation of IE. In this chapter, we will discuss the known biochemical, molecular, and structural aspects of this protein, including its interactions with extracellular matrix components and how this multifunctional adhesin may contribute to the pathogenicity of A. actinomycetemcomitans.
Collapse
Affiliation(s)
- Keith P. Mintz
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA;
| | - David R. Danforth
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA;
| | - Teresa Ruiz
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA;
| |
Collapse
|
2
|
Huang X, Xie M, Lu X, Mei F, Song W, Liu Y, Chen L. The Roles of Periodontal Bacteria in Atherosclerosis. Int J Mol Sci 2023; 24:12861. [PMID: 37629042 PMCID: PMC10454115 DOI: 10.3390/ijms241612861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/05/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
Atherosclerosis (AS) is an inflammatory vascular disease that constitutes a major underlying cause of cardiovascular diseases (CVD) and stroke. Infection is a contributing risk factor for AS. Epidemiological evidence has implicated individuals afflicted by periodontitis displaying an increased susceptibility to AS and CVD. This review concisely outlines several prevalent periodontal pathogens identified within atherosclerotic plaques, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. We review the existing epidemiological evidence elucidating the association between these pathogens and AS-related diseases, and the diverse mechanisms for which these pathogens may engage in AS, such as endothelial barrier disruption, immune system activation, facilitation of monocyte adhesion and aggregation, and promotion of foam cell formation, all of which contribute to the progression and destabilization of atherosclerotic plaques. Notably, the intricate interplay among bacteria underscores the complex impact of periodontitis on AS. In conclusion, advancing our understanding of the relationship between periodontal pathogens and AS will undoubtedly offer invaluable insights and potential therapeutic avenues for the prevention and management of AS.
Collapse
Affiliation(s)
- Xiaofei Huang
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (X.H.); (M.X.); (X.L.); (F.M.); (W.S.)
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan 430022, China
| | - Mengru Xie
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (X.H.); (M.X.); (X.L.); (F.M.); (W.S.)
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan 430022, China
| | - Xiaofeng Lu
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (X.H.); (M.X.); (X.L.); (F.M.); (W.S.)
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan 430022, China
| | - Feng Mei
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (X.H.); (M.X.); (X.L.); (F.M.); (W.S.)
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan 430022, China
| | - Wencheng Song
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (X.H.); (M.X.); (X.L.); (F.M.); (W.S.)
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan 430022, China
| | - Yang Liu
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (X.H.); (M.X.); (X.L.); (F.M.); (W.S.)
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan 430022, China
| | - Lili Chen
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (X.H.); (M.X.); (X.L.); (F.M.); (W.S.)
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan 430022, China
| |
Collapse
|
3
|
Fu Y, Maaβ S, Cavallo FM, de Jong A, Raangs E, Westra J, Buist G, Becher D, van Dijl JM. Differential Virulence of Aggregatibacter actinomycetemcomitans Serotypes Explained by Exoproteome Heterogeneity. Microbiol Spectr 2023; 11:e0329822. [PMID: 36541765 PMCID: PMC9927298 DOI: 10.1128/spectrum.03298-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative bacterial pathogen associated with periodontitis and nonoral diseases like rheumatoid arthritis and Alzheimer´s disease. Aa isolates with the serotypes a, b, and c are globally most prevalent. Importantly, isolates displaying these serotypes have different clinical presentations. While serotype b isolates are predominant in severe periodontitis, serotypes a and c are generally encountered in mild periodontitis or healthy individuals. It is currently unknown how these differences are reflected in the overall secretion of virulence factors. Therefore, this study was aimed at a comparative analysis of exoproteomes from different clinical Aa isolates with serotypes a, b, or c by mass spectrometry, and a subsequent correlation of the recorded exoproteome profiles with virulence. Overall, we identified 425 extracellular proteins. Significant differences in the exoproteome composition of isolates with different serotypes were observed in terms of protein identification and abundance. In particular, serotype a isolates presented more extracellular proteins than serotype b or c isolates. These differences are mirrored in their virulence in infection models based on human salivary gland epithelial cells and neutrophils. Remarkably, serotype a isolates displayed stronger adhesive capabilities and induced more lysis of epithelial cells and neutrophils than serotype b or c isolates. Conversely, serotype c isolates showed relatively low leukotoxicity, while provoking NETosis to similar extents as serotype a and b isolates. Altogether, we conclude that the differential virulence presentation by Aa isolates with the dominant serotypes a, b, or c can be explained by their exoproteome heterogeneity. IMPORTANCE Periodontitis is an inflammatory disease that causes progressive destruction of alveolar bone and supporting tissues around the teeth, ultimately resulting in tooth loss. The bacterium Aggregatibacter actinomycetemcomitans (Aa) is a prevalent causative agent of periodontitis, but this oral pathogen is also associated with serious extraoral diseases like rheumatoid arthritis and Alzheimer's disease. Clinical Aa isolates are usually distinguished by serotyping, because of known serotype-specific differences in virulence. Aa with serotype b is associated with aggressive forms of periodontitis, while isolates with serotypes a or c are usually encountered in cases of mild periodontitis or healthy individuals. The molecular basis for these differences in virulence was so far unknown. In the present study, we pinpoint serotype-specific differences in virulence factor production by clinical Aa isolates. We consider these findings important, because they provide new leads for future preventive or therapeutic approaches to fight periodontitis and associated morbidities.
Collapse
Affiliation(s)
- Yanyan Fu
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Sandra Maaβ
- University of Greifswald, Institute of Microbiology, Department of Microbial Proteomics, Greifswald, Germany
| | - Francis M. Cavallo
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Anne de Jong
- University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Department of Molecular Genetics, Groningen, the Netherlands
| | - Erwin Raangs
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Johanna Westra
- University of Groningen, University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, Groningen, the Netherlands
| | - Girbe Buist
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Dörte Becher
- University of Greifswald, Institute of Microbiology, Department of Microbial Proteomics, Greifswald, Germany
| | - Jan Maarten van Dijl
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| |
Collapse
|
4
|
Tang-Siegel GG. Human Serum Mediated Bacteriophage Life Cycle Switch in Aggregatibacter actinomycetemcomitans Is Linked to Pyruvate Dehydrogenase Complex. Life (Basel) 2023; 13:436. [PMID: 36836793 PMCID: PMC9959103 DOI: 10.3390/life13020436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
Antimicrobial resistance is rising as a major global public health threat and antibiotic resistance genes are widely spread among species, including human oral pathogens, e.g., Aggregatibacter actinomycetemcomitans. This Gram-negative, capnophilic, facultative anaerobe is well recognized as a causative agent leading to periodontal diseases, as well as seriously systemic infections including endocarditis. A. actinomycetemcomitans has also evolved mechanisms against complement-mediated phagocytosis and resiliently survives in serum-rich in vivo environments, i.e., inflamed periodontal pockets and blood circulations. This bacterium, however, demonstrated increasing sensitivity to human serum, when being infected by a pseudolysogenic bacteriophage S1249, which switched to the lytic state as a response to human serum. Concomitantly, the pyruvate dehydrogenase complex (PDHc), which is composed of multiple copies of three enzymes (E1, E2, and E3) and oxidatively decarboxylates pyruvate to acetyl-CoA available for tricarboxylic acid (TCA) cycle, was found up-regulated 10-fold in the bacterial lysogen after human serum exposure. The data clearly indicated that certain human serum components induced phage virion replication and egress, resulting in bacterial lysis. Phage manipulation of bacterial ATP production through regulation of PDHc, a gatekeeper linking glycolysis to TCA cycle through aerobic respiration, suggests that a more efficient energy production and delivery system is required for phage progeny replication and release in this in vivo environment. Insights into bacteriophage regulation of bacterial fitness in a mimic in vivo condition will provide alternative strategies to control bacterial infection, in addition to antibiotics.
Collapse
Affiliation(s)
- Gaoyan Grace Tang-Siegel
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont and State Agricultural College, Burlington, VT 05405, USA
| |
Collapse
|
5
|
Betancur D, Muñoz C, Oñate A. Expression of Macrophage Polarization Markers against the Most Prevalent Serotypes of Aggregatibacter actinomycetemomitans. Microorganisms 2022; 10:1384. [PMID: 35889103 DOI: 10.3390/microorganisms10071384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 11/25/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans, a Gram-negative bacterium with seven serotypes (a–g) according to the structure of its LPS, has been defined as one of the most important pathogens in the development of a dysbiotic periodontal biofilm and the onset of periodontitis (an inflammatory chronic disease of the tissues around the teeth), where the serotype b is characterized as the most virulent compared with the other serotypes. The aim of this study was to evaluate the expression of the macrophage polarization markers M0, M1, and M2 against A. actinomycetemcomitans. Methods: THP-1 cells were infected with A. actinomycetemcomitans serotypes a, b, and c. The expression of CD11b, CD4, CD14, and CD68 for M0; IL-6, HLA/DRA, and CXCL10 for M21, and IL-10, CD163, fibronectin-1 or FN1, and CCL17 was evaluated by qPCR at 2 and 24 h after infection. Results: An increase in the expression of these molecules was induced by all serotypes at both times of infection, showing higher levels of expression to the M1 panel at 2 and 24 h compared to other markers. Conclusions: A. actinomycetemcomitans has a role in the macrophage polarization to the M1 phenotype in a non-serotype-dependent manner.
Collapse
|
6
|
Fu Y, Maaβ S, du Teil Espina M, Wolters AHG, Gong Y, de Jong A, Raangs E, Buist G, Westra J, Becher D, van Dijl JM. Connections between Exoproteome Heterogeneity and Virulence in the Oral Pathogen Aggregatibacter actinomycetemcomitans. mSystems 2022; 7:e0025422. [PMID: 35695491 DOI: 10.1128/msystems.00254-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacterial pathogen associated with severe periodontitis and nonoral diseases. Clinical isolates of A. actinomycetemcomitans display a rough (R) colony phenotype with strong adherent properties. Upon prolonged culturing, nonadherent strains with a smooth (S) colony phenotype emerge. To date, most virulence studies on A. actinomycetemcomitans have been performed with S strains of A. actinomycetemcomitans, whereas the virulence of clinical R isolates has received relatively little attention. Since the extracellular proteome is the main bacterial reservoir of virulence factors, the present study was aimed at a comparative analysis of this subproteome fraction for a collection of R isolates and derivative S strains, in order to link particular proteins to the virulence of A. actinomycetemcomitans with serotype b. To assess the bacterial virulence, we applied different infection models based on larvae of the greater wax moth Galleria mellonella, a human salivary gland-derived epithelial cell line, and freshly isolated neutrophils from healthy human volunteers. A total number of 351 extracellular A. actinomycetemcomitans proteins was identified by mass spectrometry, with the S strains consistently showing more extracellular proteins than their parental R isolates. A total of 50 known extracellular virulence factors was identified, of which 15 were expressed by all investigated bacteria. Importantly, the comparison of differences in exoproteome composition and virulence highlights critical roles of 10 extracellular proteins in the different infection models. Together, our findings provide novel clues for understanding the virulence of A. actinomycetemcomitans and for development of potential preventive or therapeutic avenues to neutralize this important oral pathogen. IMPORTANCE Periodontitis is one of the most common inflammatory diseases worldwide, causing high morbidity and decreasing the quality of life of millions of people. The bacterial pathogen Aggregatibacter actinomycetemcomitans is strongly associated with aggressive forms of periodontitis. Moreover, it has been implicated in serious nonoral infections, including endocarditis and brain abscesses. Therefore, it is important to investigate how A. actinomycetemcomitans can cause disease. In the present study, we applied a mass spectrometry approach to make an inventory of the virulence factors secreted by different clinical A. actinomycetemcomitans isolates and derivative strains that emerged upon culturing. We subsequently correlated the secreted virulence factors to the pathogenicity of the investigated bacteria in different infection models. The results show that a limited number of extracellular virulence factors of A. actinomycetemcomitans have central roles in pathogenesis, indicating that they could be druggable targets to prevent or treat oral disease.
Collapse
|
7
|
Cabo ML, Rodríguez A, Herrera JR. Exploring communication signals inside the microbial community of a Listeria monocytogenes-carrying biofilm contamination site. Int J Food Microbiol 2022. [DOI: 10.1016/j.ijfoodmicro.2022.109773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/19/2022]
|
8
|
Nedergaard S, Jensen AB, Haubek D, Nørskov-Lauritsen N. Multilocus Sequence Typing of Aggregatibacter actinomycetemcomitans Competently Depicts the Population Structure of the Species. Microbiol Spectr 2021; 9:e0108521. [PMID: 34908433 DOI: 10.1128/Spectrum.01085-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We developed a multilocus sequence typing scheme (MLST) for Aggregatibacter actinomycetemcomitans based on seven housekeeping genes, adk, atpG, frdB, mdh, pgi, recA, and zwf. A total of 188 strains of seven serotypes were separated into 57 sequence types. Whole-genome sequences were available for 140 strains, and in contrast to comparison of 16S rRNA genes, phylogenetic analysis of concatenated MLST gene fragments was in accordance with the population structure revealed by alignment of 785 core genes. MLST could not decisively identify the so-called JP2 clone associated with rapidly progressing periodontitis in adolescents, but noticeable clustering of JP2 genotype strains was revealed. The MLST scheme of A. actinomycetemcomitans can be assessed at www.pubmlst.org. IMPORTANCE Accurate diagnosis of infectious disease comprise identification, typing, and antimicrobial resistance of the infective agent. Bacteria are sometimes grouped within their species according to expression of specific toxins or particular antimicrobial resistance traits, but explicit typing for infection control and survey of pathogenesis necessitates genetic analysis such as multilocus sequence typing (MLST). Schemes for the most prevalent human pathogens have been available for more than 10 years, and time has come to extend the scrutiny to second-line infectious agents. One such pathogen is Aggregatibacter actinomycetemcomitans, which is commonly involved in periodontitis, and more rarely as the cause of infective endocarditis or spontaneous brain abscess. A MLST scheme for A. actinomycetemcomitans is now available at www.pubmlst.org. Whole-genome sequencing of a large number of isolates confirms that MLST competently depicts the population structure of the species.
Collapse
|
9
|
Betancur D, Muñoz Grez C, Oñate A. Comparative Analysis of Cytokine Expression in Oral Keratinocytes and THP-1 Macrophages in Response to the Most Prevalent Serotypes of Aggregatibacter actinomycetemcomitans. Microorganisms 2021; 9:622. [PMID: 33802988 PMCID: PMC8002688 DOI: 10.3390/microorganisms9030622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/12/2021] [Accepted: 03/14/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Periodontitis is a chronic inflammatory disease associated with a dysbiotic biofilm. Many pathogens have been related with its progression and severity, one of which is Aggregatibacter actinomycetemcomitans, a Gram-negative bacteria with seven serotypes (a-g) according with the structure of its LPS, with serotype b defined as the most virulent compared with the other serotypes. The aim of this study was to evaluate the response of oral keratinocytes and macrophages to A. actinomycetemcomitans. METHODS Oral keratinocytes (OKF6/TERT2) and macrophages (THP-1) were infected with A. actinomycetemcomitans serotypes a, b and c. The expression of IL-1β, IL-6, IL-8, IL-18, TNF-α, MMP-9, RANKL, TLR-2, TLR-4, TLR-6, thymic stromal lymphopoietin (TSLP), and ICAM-1 was evaluated by qPCR at 2 and 24 h after infection. RESULTS An increase in the expression of these molecules was induced by all serotypes at both times of infection, with macrophages showing higher levels of expression at 24 h compared to epithelial cells in which the highest levels were observed in the first hours after infection. CONCLUSIONS Keratinocytes and macrophages contribute to the inflammation in periodontitis from the early stages of infection, producing the first waves of cytokines, acting as the first signal for professional immune cell recruitment and modulation of more specific immune responses.
Collapse
Affiliation(s)
| | | | - Angel Oñate
- Laboratory of Molecular Immunology, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción 4030000, Chile; (D.B.); (C.M.G.)
| |
Collapse
|
10
|
Cortelli JR, Cortelli SC, Aquino DR, Miranda TB, Jardim JCM, Costa FO. Aggregatibacter actinomycetemcomitans serotypes and JP2 outcomes related to clinical status over 6 years under periodontal maintenance therapy. Arch Oral Biol 2020; 116:104747. [PMID: 32422332 DOI: 10.1016/j.archoralbio.2020.104747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVE This 6-year study evaluatedAggregatibacter actinomycetemcomitans outcomes and their relationship to clinical status. DESIGN From the eligible individuals (23-70 years of age), 31 regular compliers (between-visit interval < 6 months) were randomly selected and matched for age/sex with 31 irregular compliers (between-visit interval > 6 months). Periodontal clinical examination and subgingival samples were obtained 5 times: T1 (baseline), T2 (after active periodontal therapy), T3 (2 years), T4 (4 years), and T5 (6 years). Total bacteria load, A. actinomycetemcomitans, and red complex species Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola levels were determined by qPCR while PCR was used to determine the occurrence of the a-b-c-d-e-f-g serotypes and the JP2 clone of A. actinomycetemcomitans. Data between groups was compared over time. RESULTS At baseline PCR revealed A. actinomycetemcomitans prevalence of 9.7 % and JP2 prevalence of 6.7 %. A. actinomycetemcomitans qPCR levels were higher among individuals < 35 years of age and increased at T2 in irregular compliers. At in irregular compliers at the three follow-up visits. Serotypes a, d, and f showed greater values in at least one follow-up visit in regular compliers. A. actinomycetemcomitans showed negative correlation with probing depth (PD) while serotype b showed negative correlations with PD, PI, clinical attachment level and red complex. CONCLUSIONS Longitudinally, compliance during PMT contributed to lower A. actinomycetemcomitans levels with some degree of correlation with clinical status. However, this study failed to report any positive effect on the occurrence of the most virulent representatives, i.e. serotype b and the JP2 clone.
Collapse
|
11
|
Stähli A, Sculean A, Eick S. JP2 Genotype of Aggregatibacter actinomycetemcomitans in Caucasian Patients: A Presentation of Two Cases. Pathogens 2020; 9:E178. [PMID: 32121596 DOI: 10.3390/pathogens9030178] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/25/2020] [Accepted: 02/25/2020] [Indexed: 12/31/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a key pathogen that has been associated with periodontal disease. Its most important virulence factor is a leukotoxin capable of inactivating immune cells. The JP2 genotype of Aggregatibacter actinomycetemcomitans shows enhanced leukotoxic activity and is mostly present in individuals of North and West African origin with severe periodontitis. In this paper, two cases of Caucasians diagnosed with the JP2 genotype are presented. A 50-year-old female patient had three approximal sites with ≥ 6 mm clinical attachment loss (CAL) and eight sites with probing depth (PD) ≥ 5 mm. Microbiological diagnostics revealed A. actinomycetemcomitans JP2 genotype, but not Porphyromonas gingivalis. This JP2 genotype was highly leukotoxic to monocytic cells. The second case was a 55-year-old female patient with CAL of > 5 mm at all molars and PD of up to 12 mm. A. actinomycetemcomitans JP2 was identified, but not P. gingivalis. Her husband originated from North-Africa. In him, no A. actinomycetemcomitans was detected, but their 17-year-old daughter was diagnosed with periodontitis and was found to be positive for the JP2 genotype. Both patients were successfully treated with adjunctive antibiotics and the JP2 genotype was eliminated. In summary, here, the microbiological diagnosis was key for the treatment with adjunctive antibiotics.
Collapse
|
12
|
Christensen H, Bossé J, Angen Ø, Nørskov-lauritsen N, Bisgaard M. Immunological and molecular techniques used for determination of serotypes in Pasteurellaceae. J Microbiol Methods 2020. [DOI: 10.1016/bs.mim.2020.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
13
|
Rojas L, Melgar-Rodríguez S, Díaz-Zúñiga J, Alvarez C, Monasterio G, Rojas C, Cafferata EA, Hernández M, Cortéz C, Carvajal P, Vernal R. Inhibitory effect of serotype a of Aggregatibacter actinomycetemcomitans on the increased destructive potential of serotype b. Oral Dis 2019; 26:409-418. [PMID: 31738464 DOI: 10.1111/odi.13237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/03/2019] [Accepted: 11/10/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The serotype b of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) induces higher cytokine production in dendritic cells (DCs) compared with the other serotypes. However, this increased immunostimulatory potential was modified when DCs were co-infected with the other A. actinomycetemcomitans serotypes. This study aimed to analyze whether the production of interferon gamma (IFN-γ), C-reactive protein (CRP), matrix metalloproteinase (MMP)-2, and MMP-9, as well as the activity of osteoclasts, also varies when DCs are co-infected with the A. actinomycetemcomitans serotypes. MATERIALS AND METHODS Human DCs were stimulated with the A. actinomycetemcomitans serotypes using the following stimulatory conditions: serotype a/b/c/a+b/a+c/b+c/a+b+c. The IFN-γ, CRP, and MMP-2 levels were quantified by ELISA. The active form of MMP-9 was quantified using fluorescent functional assays. The MMP-2 gelatinolytic activity was identified by zymogram. The osteoclast activity was determined by quantifying the TRAP expression and resorption-pit formation using cytochemistry and osteoassays. RESULTS Higher levels of IFN-γ, CRP, MMP-2, MMP-9, and osteoclast activity were detected when DCs were stimulated with the serotype b of A. actinomycetemcomitans compared with the others. This increased immunostimulatory potential attributed to serotype b diminished when DCs were co-infected with the serotype a. CONCLUSIONS This study provides new insights into the virulence of A. actinomycetemcomitans and reveals important differences in the immunostimulatory and pro-destructive potential among its serotypes.
Collapse
Affiliation(s)
- Leticia Rojas
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | | | - Jaime Díaz-Zúñiga
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Carla Alvarez
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Gustavo Monasterio
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Carolina Rojas
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Emilio A Cafferata
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Department of Periodontology, School of Dentistry, Universidad Científica del Sur, Lima, Peru
| | - Marcela Hernández
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Dentistry Unit, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| | - Cristian Cortéz
- Center for Genomics and Bioinformatics, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Paola Carvajal
- Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Rolando Vernal
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Dentistry Unit, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| |
Collapse
|
14
|
Nørskov-Lauritsen N, Claesson R, Jensen AB, Åberg CH, Haubek D. Aggregatibacter Actinomycetemcomitans: Clinical Significance of a Pathobiont Subjected to Ample Changes in Classification and Nomenclature. Pathogens 2019; 8:E243. [PMID: 31752205 PMCID: PMC6963667 DOI: 10.3390/pathogens8040243] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/10/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium that is part of the oral microbiota. The aggregative nature of this pathogen or pathobiont is crucial to its involvement in human disease. It has been cultured from non-oral infections for more than a century, while its portrayal as an aetiological agent in periodontitis has emerged more recently. A. actinomycetemcomitans is one species among a plethora of microorganisms that constitute the oral microbiota. Although A. actinomycetemcomitans encodes several putative toxins, the complex interplay with other partners of the oral microbiota and the suppression of host response may be central for inflammation and infection in the oral cavity. The aim of this review is to provide a comprehensive update on the clinical significance, classification, and characterisation of A. actinomycetemcomitans, which has exclusive or predominant host specificity for humans.
Collapse
Affiliation(s)
| | - Rolf Claesson
- Department of Odontology, Division of Oral Microbiology, Umeå University, S-901 87 Umeå, Sweden;
| | - Anne Birkeholm Jensen
- Department of Dentistry and Oral Health, Aarhus University, DK-8000 Aarhus C, Denmark;
| | - Carola Höglund Åberg
- Department of Odontology, Division of Molecular Periodontology, Umeå University, S-901 87 Umeå, Sweden
| | - Dorte Haubek
- Department of Dentistry and Oral Health, Aarhus University, DK-8000 Aarhus C, Denmark;
| |
Collapse
|
15
|
Jensen AB, Haubek D, Claesson R, Johansson A, Nørskov‐Lauritsen N. Comprehensive antimicrobial susceptibility testing of a large collection of clinical strains ofAggregatibacter actinomycetemcomitansdoes not identify resistance to amoxicillin. J Clin Periodontol 2019; 46:846-854. [DOI: 10.1111/jcpe.13148] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 03/21/2019] [Accepted: 05/20/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Anne B. Jensen
- Department of Dentistry and Oral Health Aarhus University Aarhus Denmark
- Department of Clinical Microbiology Aarhus University Hospital Aarhus Denmark
| | - Dorte Haubek
- Department of Dentistry and Oral Health Aarhus University Aarhus Denmark
| | - Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Faculty of Medicine and Odontology Umeå University Umeå Sweden
| | - Anders Johansson
- Division of Periodontology, Department of Odontology, Faculty of Medicine and Odontology Umeå University Umeå Sweden
| | | |
Collapse
|
16
|
Pietiäinen M, Liljestrand JM, Kopra E, Pussinen PJ. Mediators between oral dysbiosis and cardiovascular diseases. Eur J Oral Sci 2019; 126 Suppl 1:26-36. [PMID: 30178551 DOI: 10.1111/eos.12423] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2018] [Indexed: 12/11/2022]
Abstract
Clinical periodontitis is associated with an increased risk for cardiovascular diseases (CVDs) through systemic inflammation as the etiopathogenic link. Whether the oral microbiota, especially its quality, quantity, serology, and virulence factors, plays a role in atherogenesis is not clarified. Patients with periodontitis are exposed to bacteria and their products, which have access to the circulation directly through inflamed oral tissues and indirectly (via saliva) through the gastrointestinal tract, resulting in systemic inflammatory and immunologic responses. Periodontitis is associated with persistent endotoxemia, which has been identified as a notable cardiometabolic risk factor. The serology of bacterial biomarkers for oral dysbiosis is associated with an increased risk for subclinical atherosclerosis, prevalent and future coronary artery disease, and incident and recurrent stroke. In addition to species-specific antibodies, the immunologic response includes persistent, cross-reactive, proatherogenic antibodies against host-derived antigens. Periodontitis may affect lipoprotein metabolism at all levels, and all lipoprotein classes are affected. Periodontitis or its bacterial signatures may be involved not only in increased storage of proatherogenic lipids but also in attenuation of the anti-atherogenic processes, thereby putatively increasing the net risk of atherosclerosis. In this review we summarize possible molecular mediators between the dysbiotic oral microbiota and atherosclerotic processes.
Collapse
Affiliation(s)
- Milla Pietiäinen
- Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - John M Liljestrand
- Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Elisa Kopra
- Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Pirkko J Pussinen
- Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| |
Collapse
|
17
|
Abstract
Various gram-negative species sequester host cytokines using outer membrane proteins or surface modulation by sulfated polysaccharides. An outer membrane lipoprotein (BilRI) of the periodontal pathogen Aggregatibacter actinomycetemcomitans binds several cytokines, including interleukin (IL)-8. Because IL-8 is positively charged at physiological pH, we aimed to determine whether IL-8 interacts with negatively charged lipopolysaccharide (LPS). Binding was investigated using electrophoretic mobility shift assays and microwell-based time-resolved fluorometric immunoassay. LPS from each tested strain of A. actinomycetemcomitans (N = 13), Pseudomonas aeruginosa (N = 1) and Escherichia coli (N = 1) bound IL-8. The Kd value of the A. actinomycetemcomitans LPS-IL-8 interaction varied between 1.2–17 μM irrespective of the serotype and the amount of phosphorus in LPS and was significantly lower than that of the BilRI-IL-8 interaction. Moreover, IL-8 interacted with whole A. actinomycetemcomitans cells and outer membrane vesicles. Hence, LPS might be involved in binding of IL-8 to the outer membrane of A. actinomycetemcomitans. This raises an interesting question regarding whether other gram-negative periodontal pathogens use LPS for IL-8 sequestering in vivo.
Collapse
Affiliation(s)
- Tuuli Ahlstrand
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Laura Kovesjoki
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Terhi Maula
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Jan Oscarsson
- Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Riikka Ihalin
- Department of Biochemistry, University of Turku, Turku, Finland
| |
Collapse
|
18
|
Pietiäinen M, Kopra KAE, Vuorenkoski J, Salminen A, Paju S, Mäntylä P, Buhlin K, Liljestrand JM, Nieminen MS, Sinisalo J, Hyvärinen K, Pussinen PJ. Aggregatibacter actinomycetemcomitansserotypes associate with periodontal and coronary artery disease status. J Clin Periodontol 2018; 45:413-421. [DOI: 10.1111/jcpe.12873] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Milla Pietiäinen
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - K. A. Elisa Kopra
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Juha Vuorenkoski
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Aino Salminen
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
- Department of Dental Medicine Huddinge; Division of Periodontology; Karolinska Institutet; Huddinge Sweden
| | - Susanna Paju
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Päivi Mäntylä
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
- Institute of Dentistry; University of Eastern Finland; Kuopio Finland
- Oral and Maxillofacial Diseases; Kuopio University Hospital; Kuopio Finland
| | - Kåre Buhlin
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
- Department of Dental Medicine Huddinge; Division of Periodontology; Karolinska Institutet; Huddinge Sweden
| | - John M. Liljestrand
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Markku S. Nieminen
- Department of Cardiology, Heart and Lung Center; Helsinki University Hospital; Helsinki Finland
| | - Juha Sinisalo
- Department of Cardiology, Heart and Lung Center; Helsinki University Hospital; Helsinki Finland
| | - Kati Hyvärinen
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| | - Pirkko J. Pussinen
- Oral and Maxillofacial Diseases; University of Helsinki and Helsinki University Hospital; Helsinki Finland
| |
Collapse
|
19
|
Konig MF, Abusleme L, Reinholdt J, Palmer RJ, Teles RP, Sampson K, Rosen A, Nigrovic PA, Sokolove J, Giles JT, Moutsopoulos NM, Andrade F. Aggregatibacter actinomycetemcomitans-induced hypercitrullination links periodontal infection to autoimmunity in rheumatoid arthritis. Sci Transl Med 2017; 8:369ra176. [PMID: 27974664 DOI: 10.1126/scitranslmed.aaj1921] [Citation(s) in RCA: 351] [Impact Index Per Article: 50.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 09/09/2016] [Accepted: 11/09/2016] [Indexed: 12/16/2022]
Abstract
A bacterial etiology of rheumatoid arthritis (RA) has been suspected since the beginnings of modern germ theory. Recent studies implicate mucosal surfaces as sites of disease initiation. The common occurrence of periodontal dysbiosis in RA suggests that oral pathogens may trigger the production of disease-specific autoantibodies and arthritis in susceptible individuals. We used mass spectrometry to define the microbial composition and antigenic repertoire of gingival crevicular fluid in patients with periodontal disease and healthy controls. Periodontitis was characterized by the presence of citrullinated autoantigens that are primary immune targets in RA. The citrullinome in periodontitis mirrored patterns of hypercitrullination observed in the rheumatoid joint, implicating this mucosal site in RA pathogenesis. Proteomic signatures of several microbial species were detected in hypercitrullinated periodontitis samples. Among these, Aggregatibacter actinomycetemcomitans (Aa), but not other candidate pathogens, induced hypercitrullination in host neutrophils. We identified the pore-forming toxin leukotoxin A (LtxA) as the molecular mechanism by which Aa triggers dysregulated activation of citrullinating enzymes in neutrophils, mimicking membranolytic pathways that sustain autoantigen citrullination in the RA joint. Moreover, LtxA induced changes in neutrophil morphology mimicking extracellular trap formation, thereby releasing the hypercitrullinated cargo. Exposure to leukotoxic Aa strains was confirmed in patients with RA and was associated with both anticitrullinated protein antibodies and rheumatoid factor. The effect of human lymphocyte antigen-DRB1 shared epitope alleles on autoantibody positivity was limited to RA patients who were exposed to Aa These studies identify the periodontal pathogen Aa as a candidate bacterial trigger of autoimmunity in RA.
Collapse
Affiliation(s)
- Maximilian F Konig
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Loreto Abusleme
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jesper Reinholdt
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
| | - Robert J Palmer
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ricardo P Teles
- Department of Periodontology, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Applied Oral Sciences, Forsyth Institute, Cambridge, MA 02142, USA
| | - Kevon Sampson
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Antony Rosen
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Peter A Nigrovic
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA 02115, USA.,Division of Immunology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Jeremy Sokolove
- Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jon T Giles
- Division of Rheumatology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Niki M Moutsopoulos
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Felipe Andrade
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
| |
Collapse
|
20
|
Narayanan AM, Ramsey MM, Stacy A, Whiteley M. Defining Genetic Fitness Determinants and Creating Genomic Resources for an Oral Pathogen. Appl Environ Microbiol 2017; 83:e00797-17. [PMID: 28476775 DOI: 10.1128/AEM.00797-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/02/2017] [Indexed: 11/20/2022] Open
Abstract
Periodontitis is a microbial infection that destroys the structures that support the teeth. Although it is typically a chronic condition, rapidly progressing, aggressive forms are associated with the oral pathogen Aggregatibacter actinomycetemcomitans One of this bacterium's key virulence traits is its ability to attach to surfaces and form robust biofilms that resist killing by the host and antibiotics. Though much has been learned about A. actinomycetemcomitans since its initial discovery, we lack insight into a fundamental aspect of its basic biology, as we do not know the full set of genes that it requires for viability (the essential genome). Furthermore, research on A. actinomycetemcomitans is hampered by the field's lack of a mutant collection. To address these gaps, we used rapid transposon mutant sequencing (Tn-seq) to define the essential genomes of two strains of A. actinomycetemcomitans, revealing a core set of 319 genes. We then generated an arrayed mutant library comprising >1,500 unique insertions and used a sequencing-based approach to define each mutant's position (well and plate) in the library. To demonstrate its utility, we screened the library for mutants with weakened resistance to subinhibitory erythromycin, revealing the multidrug efflux pump AcrAB as a critical resistance factor. During the screen, we discovered that erythromycin induces A. actinomycetemcomitans to form biofilms. We therefore devised a novel Tn-seq-based screen to identify specific factors that mediate this phenotype and in follow-up experiments confirmed 4 mutants. Together, these studies present new insights and resources for investigating the basic biology and disease mechanisms of a human pathogen.IMPORTANCE Millions suffer from gum disease, which often is caused by Aggregatibacter actinomycetemcomitans, a bacterium that forms antibiotic-resistant biofilms. To fully understand any organism, we should be able to answer: what genes does it require for life? Here, we address this question for A. actinomycetemcomitans by determining the genes in its genome that cannot be mutated. As for the genes that can be mutated, we archived these mutants into a library, which we used to find genes that contribute to antibiotic resistance, leading us to discover that antibiotics cause A. actinomycetemcomitans to form biofilms. We then devised an approach to find genes that mediate this process and confirmed 4 genes. These results illuminate new fundamental traits of a human pathogen.
Collapse
|
21
|
Tang-Siegel G, Bumgarner R, Ruiz T, Kittichotirat W, Chen W, Chen C. Human Serum-Specific Activation of Alternative Sigma Factors, the Stress Responders in Aggregatibacter actinomycetemcomitans. PLoS One 2016; 11:e0160018. [PMID: 27490177 PMCID: PMC4973924 DOI: 10.1371/journal.pone.0160018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/12/2016] [Indexed: 01/08/2023] Open
Abstract
Aggregatibacter actinomycetemcomitans, a known pathogen causing periodontal disease and infective endocarditis, is a survivor in the periodontal pocket and blood stream; both environments contain serum as a nutrient source. To screen for unknown virulence factors associated with this microorganism, A. actinomycetemcomitans was grown in serum-based media to simulate its in vivo environment. Different strains of A. actinomycetemcomitans showed distinct growth phenotypes only in the presence of human serum, and they were grouped into high- and low-responder groups. High-responders comprised mainly serotype c strains, and showed an unusual growth phenomenon, featuring a second, rapid increase in turbidity after 9-h incubation that reached a final optical density 2- to 7-fold higher than low-responders. Upon further investigation, the second increase in turbidity was not caused by cell multiplication, but by cell death. Whole transcriptomic analysis via RNA-seq identified 35 genes that were up-regulated by human serum, but not horse serum, in high-responders but not in low-responders, including prominently an alternative sigma factor rpoE (σE). A lacZ reporter construct driven by the 132-bp rpoE promoter sequence of A. actinomycetemcomitans responded dramatically to human serum within 90 min of incubation only when the construct was carried by a high responder strain. The rpoE promoter is 100% identical among high- and low-responder strains. Proteomic investigation showed potential interactions between human serum protein, e.g. apolipoprotein A1 (ApoA1) and A. actinomycetemcomitans. The data clearly indicated a different activation process for rpoE in high- versus low-responder strains. This differential human serum-specific activation of rpoE, a putative extra-cytoplasmic stress responder and global regulator, suggests distinct in vivo adaptations among different strains of A. actinomycetemcomitans.
Collapse
Affiliation(s)
- Gaoyan Tang-Siegel
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, VT, United States of America
| | - Roger Bumgarner
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Teresa Ruiz
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, VT, United States of America
| | - Weerayuth Kittichotirat
- Systems Biology and Bioinformatics Research Group, Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Weizhen Chen
- Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, United States of America
| | - Casey Chen
- Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, United States of America
- * E-mail:
| |
Collapse
|
22
|
Saito M, Hirasawa M, Kuwahara N, Okada T, Umezawa K, Kobayashi T, Okamoto M, Naito M, Hirasawa M, Takada K. Complete Genome Sequence of Aggregatibacter actinomycetemcomitans Serotype g Strain NUM4039 (JCM 30399). Genome Announc 2016; 4:e00158-16. [PMID: 26988057 DOI: 10.1128/genomeA.00158-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Aggregatibacter actinomycetemcomitans is considered to be a major etiological agent of aggressive periodontitis and includes serotype a to g strains. We herein report the first complete genome sequence of A. actinomycetemcomitans serotype g strain NUM4039. The genome is 2,382,853 bp in length with a G+C content of 44.34%.
Collapse
|
23
|
Abstract
Periodontitis is an infection-induced inflammatory disease that causes loss of the tooth supporting tissues. Much focus has been put on comparison of the microbial biofilm in the healthy periodontium with the diseased one. The information arising from such studies is limited due to difficulties to compare the microbial composition in these two completely different ecological niches. A few longitudinal studies have contributed with information that makes it possible to predict which individuals who might have an increased risk of developing aggressive forms of periodontitis, and the predictors are either microbial or/and host-derived factors. The most conspicuous condition that is associated with disease risk is the presence of Aggregatibacter actinomycetemcomitans at the individual level. This Gram-negative bacterium has a great genetic variation with a number of virulence factors. In this review we focus in particular on the leukotoxin that, based on resent knowledge, might be one of the most important virulence factors of A. actinomycetemcomitans.
Collapse
Affiliation(s)
- Carola Höglund Åberg
- a Division of Molecular Periodontology; Department of Odontology; Faculty of Medicine; Umeå University ; Umeå , Sweden
| | | | | |
Collapse
|
24
|
Maraghehpour B, Khayamzadeh M, Najafi S, Kharazifard M. Traditionally used herbal medicines with antibacterial effect on Aggegatibacter actinomycetemcomitans: Boswellia serrata and Nigella sativa. J Indian Soc Periodontol 2016; 20:603-607. [PMID: 29238140 PMCID: PMC5713083 DOI: 10.4103/jisp.jisp_12_17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background: Since bacterial strains developed resistance against commonly used antibiotics and side effects became more serious, other alternatives have been postulated. There is an answer for this issue in ancient medicine. Many plants have been proved to provide antibacterial effect. In this study, Boswellia serrata (BS) and Nigella sativa (NS) were assessed to evaluate the antibacterial effect on Aggregatibacter actinomycetemcomitans (A.a) known as main pathogen of aggressive periodontitis. Materials and Methods: Broth microdilution method was used to obtain minimum inhibitory concentration (MIC) of crude extract of BS and NS. Furthermore, the logarithm of colony forming units grown in fresh brain heart infusion bacterial culture was assessed. Three groups including BS+ (containing only BS), NS+ (containing only NS), and BS-NS− (control group) were defined. For each group, the experiment was repeated 12 times. Results: MIC of BS and NS were 512 μg/mL and 128 μg/mL, respectively. No growth was observed in our negative control group. The mean ± standard deviation of logarithm of CFU/mL for BS, NS, and control group was 4.32 ± 0.36, 3.61 ± 0.3, and 5.57 ± 0.19, respectively. ANOVA test revealed significant difference (P values < 0.0001) of these groups which was later confirmed using the post hoc test of Tukey's honest significant difference (all P < 0.0001). Conclusions: Both BS and NS are effective against A.a which should be taken into account as appropriate ingredient for oral hygiene products.
Collapse
Affiliation(s)
- Bita Maraghehpour
- Department of Oral Medicine, International Campus, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Mina Khayamzadeh
- Department of Oral Medicine, International Campus, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Shamsoulmolouk Najafi
- Department of Oral Medicine, International Campus, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.,Department of Oral Medicine, Dental Research Center, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammadjavad Kharazifard
- Department of Oral Medicine, International Campus, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
25
|
Abstract
For decades, Aggregatibacter actinomycetemcomitans has been considered the most likely etiologic agent in aggressive periodontitis. Implementation of DNA-based microbiologic methodologies has considerably improved our understanding of the composition of subgingival biofilms, and advanced open-ended molecular techniques even allow for genome mapping of the whole bacterial spectrum in a sample and characterization of both the cultivable and not-yet-cultivable microbiota associated with periodontal health and disease. Currently, A. actinomycetemcomitans is regarded as a minor component of the resident oral microbiota and as an opportunistic pathogen in some individuals. Its specific JP2 clone, however, shows properties of a true exogenous pathogen and has an important role in the development of aggressive periodontitis in certain populations. Still, limited data exist on the impact of other microbes specifically in aggressive periodontitis. Despite a wide heterogeneity of bacteria, especially in subgingival samples collected from patients, bacteria of the red complex in particular, and those of the orange complex, are considered as potential pathogens in generalized aggressive periodontitis. These types of bacterial findings closely resemble those found for chronic periodontitis, representing a mixed polymicrobial infection without a clear association with any specific microorganism. In aggressive periodontitis, the role of novel and not-yet-cultivable bacteria has not yet been elucidated. There are geographic and ethnic differences in the carriage of periodontitis-associated microorganisms, and they need to be taken into account when comparing study reports on periodontal microbiology in different study populations. In the present review, we provide an overview on the colonization of potential periodontal pathogens in childhood and adolescence, and on specific microorganisms that have been suspected for their role in the initiation and progression of aggressive forms of periodontal disease.
Collapse
|
26
|
Tsuzukibashi O, Saito M, Kobayashi T, Umezawa K, Nagahama F, Hiroi T, Hirasawa M, Takada K. A gene cluster for the synthesis of serotype g-specific polysaccharide antigen in Aggregatibacter actinomycetemcomitans. Arch Microbiol 2014; 196:261-5. [PMID: 24562973 DOI: 10.1007/s00203-014-0965-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 02/10/2014] [Indexed: 11/29/2022]
Abstract
Aggregatibacter actinomycetemcomitans is an important pathogen related to aggressively progressive periodontal breakdown in adolescents and adults. The species can be divided into six serotypes (a-f) according to their surface carbohydrate antigens. Recently, a new serotype g of A. actinomycetemcomitans was proposed. The aim of the present study was to sequence the gene cluster associated with the biosynthesis of the serotype g-specific polysaccharide antigen and develop serotype-specific primers for PCR assay to identify serotype g strains of A. actinomycetemcomitans. The serotype-specific polysaccharide (SSPS) gene cluster of the NUM-Aa 4039 strain contained 21 genes in 21,842-bp nucleotides. The similarity of the SSPS gene cluster sequence was 96.7 % compared with that of the serotype e strain. Seventeen serotype g genes showed more than 90 % homology both in nucleotide and amino acids to the serotype e strain. Three additional genes with 1,579 bp in NUM-Aa 4039 were inserted into the corresponding ORF13 of the serotype e strain. The serotype g-specific primers were designed from the insertion region of NUM-Aa 4039. Serotypes of the a-f strains were not amplified by serotype-specific g primers; only NUM-Aa 4039 showed an amplicon band. The NUM-Aa 4039 strain was three genes in the SSPS gene cluster different from those of serotype e strain. The specific primers derived from these different regions are useful for identification and distribution of serotype g strain among A. actinomycetemcomitans from clinical samples.
Collapse
Affiliation(s)
- Osamu Tsuzukibashi
- Department of Oral Microbiology, Nihon University School of Dentistry at Matsudo, 2-870-1 Sakaecho-Nishi, Matsudo, Chiba, 271-8587, Japan
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Sol A, Ginesin O, Chaushu S, Karra L, Coppenhagen-Glazer S, Ginsburg I, Bachrach G. LL-37 opsonizes and inhibits biofilm formation of Aggregatibacter actinomycetemcomitans at subbactericidal concentrations. Infect Immun 2013; 81:3577-85. [PMID: 23836819 PMCID: PMC3811755 DOI: 10.1128/iai.01288-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 07/02/2013] [Indexed: 12/26/2022] Open
Abstract
Host defense peptides are immediate responders of the innate immunity that express antimicrobial, immunoregulatory, and wound-healing activities. Neutrophils are a major source for oral host defense peptides, and phagocytosis by neutrophils is a major mechanism for bacterial clearance in the gingival tissue. Dysfunction of or reduction in the numbers of neutrophils or deficiency in the LL-37 host defense peptide was each previously linked with proliferation of oral Aggregatibacter actinomycetemcomitans which resulted in an aggressive periodontal disease. Surprisingly, A. actinomycetemcomitans shows resistance to high concentrations of LL-37. In this study, we demonstrated that submicrocidal concentrations of LL-37 inhibit biofilm formation by A. actinomycetemcomitans and act as opsonins and agglutinins that greatly enhance its clearance by neutrophils and macrophages. Improved uptake of A. actinomycetemcomitans by neutrophils was mediated by their opsonization with LL-37. Enhanced phagocytosis and killing of A. actinomycetemcomitans by murine macrophage-like RAW 264.7 cells were dependent on their preagglutination by LL-37. Although A. actinomycetemcomitans is resistant to the bactericidal effect of LL-37, our results offer a rationale for the epidemiological association between LL-37 deficiency and the expansion of oral A. actinomycetemcomitans and indicate a possible therapeutic use of cationic peptides for host defense.
Collapse
Affiliation(s)
| | | | - Stella Chaushu
- Department of Orthodontics, The Hebrew University—Hadassah School of Dental Medicine
| | - Laila Karra
- Department of Pharmacology and Experimental Therapeutics, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | | | | |
Collapse
|
28
|
Young RE, Twelkmeyer B, Vitiazeva V, Power PM, Schweda EK, Hood DW. Haemophilus parainfluenzae expresses diverse lipopolysaccharide O-antigens using ABC transporter and Wzy polymerase-dependent mechanisms. Int J Med Microbiol 2013; 303:603-17. [PMID: 24035104 DOI: 10.1016/j.ijmm.2013.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/09/2013] [Accepted: 08/18/2013] [Indexed: 12/11/2022] Open
Abstract
Lipopolysaccharide O-antigens are the basis of serotyping schemes for Gram negative bacteria and help to determine the nature of host–bacterial interactions. Haemophilus parainfluenzae is a normal commensal of humans but is also an occasional pathogen. The prevalence, diversity and biosynthesis of O-antigens were investigated in this species for the first time. 18/18 commensal H. parainfluenzae isolates contain a O-antigen biosynthesis gene cluster flanked by glnA and pepB, the same position as the hmg locus for tetrasaccharide biosynthesis in Haemophilus influenzae. The O-antigen loci show diverse restriction digest patterns but fall into two main groups: (1) those encoding enzymes for the synthesis and transfer of FucNAc4N in addition to the Wzy-dependent mechanism of O-antigen synthesis and transport and (2) those encoding galactofuranose synthesis/transfer enzymes and an ABC transporter. The other glycosyltransferase genes differ between isolates. Three H. parainfluenzae isolates fell outside these groups and are predicted to synthesise O-antigens containing ribitol phosphate or deoxytalose. Isolates using the ABC transporter system encode a putative O-antigen ligase, required for the synthesis of O-antigen-containing LPS glycoforms, at a separate genomic location. The presence of an O-antigen contributes significantly to H. parainfluenzae resistance to the killing effect of human serum in vitro. The discovery of O-antigens in H. parainfluenzae is striking, as its close relative H. influenzae lacks this cell surface component.
Collapse
|
29
|
Sun R, Kittichotirat W, Wang J, Jan M, Chen W, Asikainen S, Bumgarner R, Chen C. Genomic Stability of Aggregatibacter actinomycetemcomitans during Persistent Oral Infection in Human. PLoS One 2013; 8:e66472. [PMID: 23824402 PMCID: PMC3688926 DOI: 10.1371/journal.pone.0066472] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 05/07/2013] [Indexed: 01/22/2023] Open
Abstract
The genome of periodontal pathogen Aggregatibacter actinomycetemcomitans exhibits substantial variations in gene content among unrelated strains primarily due to the presence or absence of genomic islands. This study examined the genomic stability of A. actinomycetemcomitans during its persistent infection in the same host. Four pairs of A. actinomycetemcomitans strains, each pair isolated from an individual over time (0–10 years), were examined for their gains/losses of genes by whole genome sequencing, comparative genomic hybridization by microarray and PCR analysis. Possible effects due to genomic changes were further assessed by comparative transcriptome analysis using microarrays. The results showed that each pair of strains was clonally identical based on phylogenetic analysis of 150 core genes. A novel 24.1-Kb plasmid found in strain S23A was apparently lost in the sibling strain I23C. A 353-bp inversion affecting two essential genes of the serotype-specific gene cluster was found in the serotype antigen-nonexpressing strain I23C, while the same gene cluster was intact in the serotype-expressing sibling strain S23A. A 2,293-bp deletion affecting a gene encoding oxaloacetate decarboxylase and its neighbor region was found in strain SCC2302 but not in the sibling strain AAS4a. However, no evidence of gains or losses of genomic islands was found in the paired strains. Transcriptome profiles showed little or no difference in the paired strains. In conclusion, the genome of A. actinomycetemcomitans appears to be relatively stable during short-term infection. Several types of genomic changes were observed in the paired strains of A. actinomycetemcomitans recovered from the same subjects, including a mutation in serotype-specific gene cluster that may allow the bacteria to evade host immune response.
Collapse
Affiliation(s)
- Ruoxing Sun
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Herman Ostrow School of Dentistry of the University of Southern California, Los Angeles, California, United States of America
| | - Weerayuth Kittichotirat
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- Systems Biology and Bioinformatics Research Group, Pilot Plant, Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok, Thailand
| | - Justin Wang
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Herman Ostrow School of Dentistry of the University of Southern California, Los Angeles, California, United States of America
| | - Minnie Jan
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Herman Ostrow School of Dentistry of the University of Southern California, Los Angeles, California, United States of America
| | - Weizhen Chen
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Herman Ostrow School of Dentistry of the University of Southern California, Los Angeles, California, United States of America
| | | | - Roger Bumgarner
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Casey Chen
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Herman Ostrow School of Dentistry of the University of Southern California, Los Angeles, California, United States of America
- * E-mail:
| |
Collapse
|
30
|
Höglund Åberg C, Antonoglou G, Haubek D, Kwamin F, Claesson R, Johansson A. Cytolethal distending toxin in isolates of Aggregatibacter actinomycetemcomitans from Ghanaian adolescents and association with serotype and disease progression. PLoS One 2013; 8:e65781. [PMID: 23922633 PMCID: PMC3683020 DOI: 10.1371/journal.pone.0065781] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 04/28/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The cytolethal distending toxin (Cdt) is a highly conserved exotoxin that are produced by a number of Gram negative bacteria, including Aggregatibacter actinomycetemcomitans, and affects mammalian cells by inhibiting cell division and causing apoptosis. A complete cdt-operon is present in the majority of A. actinomycetemcomitans, but the proportion of isolates that lack cdt-encoding genes (A, B and C) varies according to the population studied. The objectives of this study were to examine serotype, Cdt-genotype, and Cdt-activity in isolates of A. actinomycetemcomitans collected from an adolescent West African population and to examine the association between the carrier status of A. actinomycetemcomitans and the progression of attachment loss (AL). MATERIALS AND METHODS A total of 249 A. actinomycetemcomitans isolates from 200 Ghanaian adolescents were examined for serotype and cdt-genotype by PCR. The activity of the Cdt-toxin was examined by DNA-staining of exposed cultured cells and documented with flow cytometry. The periodontal status of the participants was examined at baseline and at a two-year follow-up. RESULTS Presence of all three cdt-encoding genes was detected in 79% of the examined A. actinomycetemcomitans isolates. All these isolates showed a substantial Cdt-activity. The two different cdt-genotypes (with and without presence of all three cdt-encoding genes) showed a serotype-dependent distribution pattern. Presence of A. actinomycetemcomitans was significantly associated with progression of AL (OR = 5.126; 95% CI = [2.994-8.779], p<0.001). CONCLUSION A. actinomycetemcomitans isolated from the Ghanaian adolescents showed a distribution of serotype and cdt-genotype in line with results based on other previously studied populations. Presence of A. actinomycetemcomitans was significantly associated with disease progression, in particular the b serotype, whereas the association with disease progression was not particularly related to cdt-genotype, and Cdt-activity.
Collapse
Affiliation(s)
- Carola Höglund Åberg
- Division of Molecular Periodontology, Department of Odontology, Faculty of Medicine, Umeå University, Umeå, Sweden
| | - Georgios Antonoglou
- Division of Molecular Periodontology, Department of Odontology, Faculty of Medicine, Umeå University, Umeå, Sweden
| | - Dorte Haubek
- Section for Pediatric Dentistry, Department of Dentistry, Health, Aarhus University, Aarhus, Denmark
| | | | - Rolf Claesson
- Division of Oral Microbiology, Department of Odontology, Faculty of Medicine, Umeå University, Umeå, Sweden
| | - Anders Johansson
- Division of Molecular Periodontology, Department of Odontology, Faculty of Medicine, Umeå University, Umeå, Sweden
- * E-mail:
| |
Collapse
|
31
|
|
32
|
Kilár A, Dörnyei Á, Kocsis B. Structural characterization of bacterial lipopolysaccharides with mass spectrometry and on- and off-line separation techniques. Mass Spectrom Rev 2013; 32:90-117. [PMID: 23165926 DOI: 10.1002/mas.21352] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 03/27/2012] [Accepted: 03/27/2012] [Indexed: 06/01/2023]
Abstract
The focus of this review is the application of mass spectrometry to the structural characterization of bacterial lipopolysaccharides (LPSs), also referred to as "endotoxins," because they elicit the strong immune response in infected organisms. Recently, a wide variety of MS-based applications have been implemented to the structure elucidation of LPS. Methodological improvements, as well as on- and off-line separation procedures, proved the versatility of mass spectrometry to study complex LPS mixtures. Special attention is given in the review to the tandem mass spectrometric methods and protocols for the analyses of lipid A, the endotoxic principle of LPS. We compare and evaluate the different ionization techniques (MALDI, ESI) in view of their use in intact R- and S-type LPS and lipid A studies. Methods for sample preparation of LPS prior to mass spectrometric analysis are also described. The direct identification of intrinsic heterogeneities of most intact LPS and lipid A preparations is a particular challenge, for which separation techniques (e.g., TLC, slab-PAGE, CE, GC, HPLC) combined with mass spectrometry are often necessary. A brief summary of these combined methodologies to profile LPS molecular species is provided.
Collapse
Affiliation(s)
- Anikó Kilár
- Department of Analytical and Environmental Chemistry, Institute of Chemistry, Faculty of Sciences, University of Pécs, Pécs, Hungary.
| | | | | |
Collapse
|
33
|
Kikuchi H, Fujise O, Miura M, Tanaka A, Hisano K, Haraguchi A, Hamachi T, Maeda K. Serotype-dependent expression patterns of stabilized lipopolysaccharide aggregates inAggregatibacter actinomycetemcomitansstrains. Microbiol Immunol 2012; 56:680-91. [DOI: 10.1111/j.1348-0421.2012.00492.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
34
|
Ganeshnarayan K, Velliyagounder K, Furgang D, Fine DH. Human salivary cystatin SA exhibits antimicrobial effect against Aggregatibacter actinomycetemcomitans. J Periodontal Res 2012; 47:661-73. [DOI: 10.1111/j.1600-0765.2012.01481.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
35
|
Chen C, Kittichotirat W, Chen W, Downey JS, Bumgarner R. Genome sequence of a serotype b non-JP2 aggregatibacter actinomycetemcomitans strain, ANH9381, from a periodontally healthy individual. J Bacteriol 2012; 194:1837. [PMID: 22408240 DOI: 10.1128/JB.06770-11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gram-negative Aggregatibacter actinomycetemcomitans can be distinguished (based on the promoter structure of the leukotoxin operon) into JP2 and non-JP2 genotypes, with the former found to be more pathogenic than the latter. Here we report the first complete genome sequence of a serotype b non-JP2 strain of A. actinomycetemcomitans.
Collapse
|
36
|
Bandhaya P, Saraithong P, Likittanasombat K, Hengprasith B, Torrungruang K. Aggregatibacter actinomycetemcomitans serotypes, the JP2 clone and cytolethal distending toxin genes in a Thai population. J Clin Periodontol 2012; 39:519-25. [PMID: 22471788 DOI: 10.1111/j.1600-051x.2012.01871.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2012] [Indexed: 11/27/2022]
Abstract
AIM To examine the genetic diversity of Aggregatibacter actinomycetemcomitans in Thai adults. MATERIALS AND METHODS Subgingival plaque samples from 453 subjects were analysed for A. actinomycetemcomitans serotypes, the presence of the high leukotoxin-producing JP2 clone and cytolethal distending toxin genes (cdtABC) using the polymerase chain reaction technique. In subjects who were positive for cdtABC, restriction fragment length polymorphism analysis was used to identify a single nucleotide polymorphism (SNP) in the cdtB gene at amino acid position 281. The extent and severity of periodontal disease were compared between subjects harbouring different A. actinomycetemcomitans genotypes. RESULTS Eighty six subjects (19%) were positive for A. actinomycetemcomitans. The JP2 clone was not detected. Serotype c was the most prevalent (57%), followed by serotypes a (33%) and b (7%). Among A. actinomycetemcomitans-positive subjects, 27% were positive for cdtABC. All cdtABC-positive subjects possessed the SNP in the cdtB, which is involved with increased toxin activity. The presence of A. actinomycetemcomitans, but not a specific genotype, was significantly related to increased probing depth and periodontal attachment loss. CONCLUSIONS Our results confirm the previous findings that genotype distribution of A. actinomycetemcomitans varies between ethnic groups. However, no clear relationship between a specific genotype and periodontal conditions was observed.
Collapse
Affiliation(s)
- Panwadee Bandhaya
- Section of Periodontology, Department of Restorative Dentistry and Periodontology, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand
| | | | | | | | | |
Collapse
|
37
|
Jentsch H, Cachovan G, Guentsch A, Eickholz P, Pfister W, Eick S. Characterization of Aggregatibacter actinomycetemcomitans strains in periodontitis patients in Germany. Clin Oral Investig 2012; 16:1589-97. [DOI: 10.1007/s00784-012-0672-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Accepted: 01/02/2012] [Indexed: 11/30/2022]
|
38
|
Abstract
We previously reported that lipopolysaccharide (LPS) -related sugars are associated with the glycosylation of the collagen adhesin EmaA, a virulence determinant of Aggregatibacter actinomycetemcomitans. In this study, the role of LPS in the secretion of other virulence factors was investigated. The secretion of the epithelial adhesin Aae, the immunoglobulin Fc receptor Omp34 and leukotoxin were examined in a mutant strain with inactivated TDP-4-keto-6-deoxy-d-glucose 3,5-epimerase (rmlC), which resulted in altered O-antigen polysaccharides (O-PS) of LPS. The secretion of Aae and Omp34 was not affected. However, the leukotoxin secretion, which is mediated by the TolC-dependent type I secretion system, was altered in the rmlC mutant. The amount of secreted leukotoxin in the bacterial growth medium was reduced nine-fold, with a concurrent four-fold increase of the membrane-bound toxin in the mutant compared with the wild-type strain. The altered leukotoxin secretion pattern was restored to the wild-type by complementation of the rmlC gene in trans. Examination of the ltxA mRNA levels indicated that the leukotoxin secretion was post-transcriptionally regulated in the modified O-PS containing strain. The mutant strain also showed increased resistance to vancomycin, an antibiotic dependent on TolC for internalization, indicating that TolC was affected. Overexpression of TolC in the rmlC mutant resulted in an increased TolC level in the outer membrane but did not restore the leukotoxin secretion profile to the wild-type phenotype. The data suggest that O-PS mediate leukotoxin secretion in A. actinomycetemcomitans.
Collapse
Affiliation(s)
- G Tang
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
| | | | | | | |
Collapse
|
39
|
Castillo-Ruiz M, Vinés ED, Montt C, Fernández J, Delgado JM, Hormazábal JC, Bittner M. Isolation of a novel Aggregatibacter actinomycetemcomitans serotype b bacteriophage capable of lysing bacteria within a biofilm. Appl Environ Microbiol 2011; 77:3157-9. [PMID: 21378052 DOI: 10.1128/AEM.02115-10] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A bacteriophage specific for Aggregatibacter actinomycetemcomitans serotype b, able to kill the bacterium within a biofilm, was isolated. Random mutagenesis of this phage rendered a bacteriophage able to kill 99% of the bacteria within a biofilm. This is the first report of a biocontrol experiment against A. actinomycetemcomitans.
Collapse
|
40
|
Elamin A, Albandar JM, Poulsen K, Ali RW, Bakken V. Prevalence of Aggregatibacter actinomycetemcomitans in Sudanese patients with aggressive periodontitis: a case-control study. J Periodontal Res 2011; 46:285-91. [DOI: 10.1111/j.1600-0765.2010.01337.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|