Leukotoxin A Production and Release by JP2 and Non-JP2 Genotype in Relation to Culture Conditions.

Aggressive forms of periodontitis, especially in young patients, are often associated with an increased proportion of the Gram-negative bacterium of the microbiota of the affected periodontal sites. One of the virulence factors of is a leukotoxin (LtxA) that induces a pro-inflammatory cell death process in leukocytes. exhibits a large genetic diversity and different genotypes vary in LtxA production capacity.

Association of and its RTX toxin gene with periodontal attachment loss, and in synergy with .

The Gram-positive bacterium, is an oral pathogen, and approximately 50% of known strains encode a recently identified repeat-in-toxin (RTX) protein, FtxA. By assessing a longitudinal Ghanaian study population of adolescents (10-19 years of age; mean age 13.2 years), we recently discovered a possible correlation between deep periodontal pockets measured at the two-year follow-up, presence of the gene, and a high quantity of .

Age-Related Subgingival Colonization of , and -A Pragmatic Microbiological Retrospective Report.

The aim of this study was to compare data about the prevalence and proportions of the bacterial species , , and in periodontitis pocket samples collected from young, <35 years, and old, >35-year-old patients, YP and OP, respectively. The results from the analyses of a total of 3447 subgingival plaque samples analyzed for clinical diagnosis purposes by cultivation regarding the proportions of these species were collected from a database and elucidated. The prevalence of A.

and as Associated with Periodontal Attachment Loss in a Cohort of Ghanaian Adolescents.

The aims of the present study were to document the presence of and the emerging oral pathogen , as well as to identify genotypes of these bacterial species with enhanced virulence. In addition, these data were analyzed in relation to periodontal pocket depth (PPD) and the progression of PPD from the sampled periodontal sites during a two-year period. Subgingival plaque samples were collected from 172 periodontal pockets of 68 Ghanaian adolescents.

Radiographic and clinical signs of periodontitis and associated bacterial species in a Swedish adolescent population.

Background: Periodontitis in adolescents has historically been rare in the Nordic countries but could be expected to increase due to changing demographics. The primary aim was to cross-sectionally examine the presence of radiographic bone loss in adolescents in Västerbotten County, Sweden. The secondary aim was to compare periodontal and microbial parameters, as well as demographic patterns, between controls without bone loss and cases with bone loss.

Carriage of the JP2 Genotype of by Periodontitis Patients of Various Geographic Origin, Living in Sweden.

The JP2 genotype of Aggregatibacter actinomycetemcomitans serotype b is associated with aggressive forms of periodontitis and was initially identified as affecting adolescents in North and West Africa. The dissemination of this genotype follows the migration routes and can today be detected in samples from periodontitis patients in a high number of countries. In the present study, we aim to describe findings of the JP2 genotype A.

Clinical laboratory diagnostics in dentistry: Application of microbiological methods.

Diagnosis and treatment in dentistry are based on clinical examination of the patients. Given that the major oral diseases are of microbial biofilm etiology, it can be expected that performing microbiological analysis on samples collected from the patient could deliver supportive evidence to facilitate the decision-making process by the clinician. Applicable microbiological methods range from microscopy, to culture, to molecular techniques, which can be performed easily within dedicated laboratories proximal to the clinics, such as ones in academic dental institutions.

Extracellular Vesicle Subproteome Differences among Clinical Isolates.

is a Gram-positive asaccharolytic, obligate anaerobic rod of the Firmicutes phylum, which has recently been implicated in oral infections. Extracellular vesicles (EVs) are crucial conveyors of microbial virulence in bacteria and archaea. Previously, in highly purified EVs from the reference strain ATCC 35896 (CCUG 47790), 28 proteins were identified.

Proteomic Characterization of the Oral Pathogen Reveals Key Inter-Protein Interactions of Its RTX Toxin: FtxA.

is a Gram-positive asaccharolytic, obligate anaerobic rod that has been isolated from a variety of oral infections including periodontitis, peri-implantitis, and odontogenic abscesses. As a newly emerging pathogen, its type strain has been investigated for pathogenic properties, yet little is known about its virulence variations among strains. We previously screened the whole genome of nine clinical oral isolates and a reference strain of , and they expressed a novel RTX toxin, FtxA.

The Highly Leukotoxic JP2 Genotype of Is Present in the Population of the West African Island, Sal in Cape Verde: A Pilot Study.

is strongly associated with severe periodontitis, possibly due to its production of a potent leukotoxin. A genetic variant, the JP2 genotype, was found to produce more leukotoxin than the wild type because of a mutation in the leukotoxin gene, and this genotype is frequently found in African populations. The aim of this study was to investigate whether this JP2 genotype can be found in a randomly selected group of inhabitants of Sal, Cape Verde.

Discrepancies in Antimicrobial Susceptibility between the JP2 and the Non-JP2 Genotype of .

The Aggregatibacter actinomycetemcomitans JP2 genotype is associated with high leukotoxin production and severe (aggressive) periodontitis. The aim of this study was to compare the antimicrobial susceptibility of JP2 and non-JP2 genotype strains. Minimal inhibitory concentrations (MICs) of 11 antimicrobials were determined for 160 A.

Multilocus Sequence Typing of Non-JP2 Serotype b Strains of Ghanaian and Swedish Origin.

Objective And Methods: The Gram-negative bacterium, is associated with periodontitis affecting young individuals. The geographic dissemination of the highly leukotoxic JP2 genotype of serotype b of this species was previously studied by multilocus sequence typing (MLST). Here, we have used MLST to genetically characterize non-JP2 genotype strains of serotype b, isolated from individuals living in Ghana (n=41), and in Sweden (n=13), respectively.

and in a Kenyan Maasai Adolescent Population and Inhibition of Leukotoxic Activity by Herbal Plants Used as Part of Oral Hygiene Procedures.

Background: A virulent genotype (JP2) of the periodonto-pathogen, (), is widespread in North and West Africa, while its presence in East Africa has not been thoroughly investigated. This JP2 genotype is associated with periodontitis in adolescents and has a high leukotoxicity. The aim of the study was to examine the prevalence of and its JP2 genotype, the prevalence of the oral, commensal in a Maasai adolescent population, and the effect of herbal plants for inhibition of leukotoxicity.

Porphyromonas gingivalis fimbrial protein Mfa5 contains a von Willebrand factor domain and an intramolecular isopeptide.

The Gram-negative bacterium Porphyromonas gingivalis is a secondary colonizer of the oral biofilm and is involved in the onset and progression of periodontitis. Its fimbriae, of type-V, are important for attachment to other microorganisms in the biofilm and for adhesion to host cells. The fimbriae are assembled from five proteins encoded by the mfa1 operon, of which Mfa5 is one of the ancillary tip proteins.

Phylogenetic Analysis of Strains Isolated from Several Oral Infections Identified a Novel RTX Toxin, FtxA.

is a Gram-positive asaccharolytic, obligate anaerobic rod of the phylum Firmicutes, and is considered an emerging pathogen in various oral infections, including periodontitis. We here aimed to perform phylogenetic analysis of a genome-sequenced type strain (ATCC 35896; CCUG 47790), as well as nine clinical oral strains that we have independently isolated and sequenced, for identification and deeper characterization of novel genomic elements of virulence in this species. We identified that 60% of the strains carried a gene encoding a hitherto unrecognized member of the large repeats-in-toxins (RTX) family, which we have designated as FtxA.

Characterization of Serotype b Strains with Five Different, Including Two Novel, Leukotoxin Promoter Structures.

The JP2 genotype of , serotype b has attracted much interest during the past three decades due to its close association with periodontitis in young individuals and the enhanced expression of a leukotoxin (LtxA). A typical feature of this genotype is a 530-base pair (bp) deletion in the promoter region controlling leukotoxin expression. In the present work, we have characterized serotype b strains with four additional promoter types.

43-Year Temporal Trends in Immune Response to Oral Bacteria in a Swedish Population.

Bacteria colonizing the mouth induce an adaptive immune response with the systemic and local presence of species or strain-specific immunoglobulins. Few studies have addressed global antibody patterns for oral bacteria or potential population time trends. We assessed these aspects in relation to a panel of oral bacteria.

Chemical Composition, Antimicrobial activity, in Vitro Cytotoxicity and Leukotoxin Neutralization of Essential Oil from against .

In this study, the essential oil of was evaluated for putative antibacterial activity against six clinical strains and five reference strains of , in comparison with some antimicrobials. The chemical composition of the essential oil was analyzed, using chromatography (CG) and gas chromatography-mass spectrometry coupled (CG-MS). The major compounds in the oil were Carvacrol (32.

: Clinical Significance of a Pathobiont Subjected to Ample Changes in Classification and Nomenclature.

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.

Differential Cell Lysis Among Periodontal Strains of JP2 and Non-JP2 Genotype of Serotype B Is Not Reflected in Dissimilar Expression and Production of Leukotoxin.

Leukotoxic potential of strains has been studied by the use of several methods, and results differ depending on the methods used. The aim of the present study was to perform a comprehensive examination of the leukotoxic potential of a collection of strains by use of three quantitative methods, Western blotting, ELISA, and mRNA expression assay and compare these results with previous data obtained by a cell lysis assay. A higher leukotoxic potential among JP2 genotype strains compared to non-JP2 genotype strains of was found by Western blotting, ELISA and mRNA expression assay.

Genetic Profiling of Serotype B Isolated from Periodontitis Patients Living in Sweden.

The bacterium is associated with aggressive forms of periodontitis and with systemic diseases, such as endocarditis. By assessing a Ghanaian longitudinal adolescent cohort, we earlier recognized the gene as a possible diagnostic marker for a subgroup of JP2 and non-JP2 genotype serotype b strains, associated with high leukotoxicity as determined in a semi-quantitative cell assay. This group of is associated with the progression of attachment loss.

Tools of to Evade the Host Response.

Periodontitis is an infection-induced inflammatory disease that affects the tooth supporting tissues, i.e., bone and connective tissues.

Comprehensive antimicrobial susceptibility testing of a large collection of clinical strains of Aggregatibacter actinomycetemcomitans does not identify resistance to amoxicillin.

Aim: The present study aims to determine the susceptibility of Aggregatibacter actinomycetemcomitans to amoxicillin by investigating a large collection of oral strains of diverse geographical origin.

Methods: Two hundred and fifty-seven A. actinomycetemcomitans strains were serotyped using a multiplex polymerase chain reaction, and minimal inhibitory concentration (MIC) values of amoxicillin were determined using the agar dilution method (range 0.

High salivary levels of JP2 genotype of Aggregatibacter actinomycetemcomitans is associated with clinical attachment loss in Moroccan adolescents.

It has previously been shown that the presence of in subgingival plaque is significantly associated with increased risk for clinical attachment loss. The highly leukotoxic JP2 genotype of this bacterium is frequently detected in adolescents with aggressive forms of periodontitis. The aims of the study were to quantify the levels of JP2 and non-JP2 genotypes of in saliva of Moroccan adolescents with the JP2 genotype earlier detected in the subgingival plaque.

Evasion of Immune Surveillance in Low Oxygen Environments Enhances Candida albicans Virulence.

Microbial colonizers of humans have evolved to adapt to environmental cues and to sense nutrient availability. Oxygen is a constantly changing environmental parameter in different host tissues and in different types of infection. We describe how , an opportunistic fungal pathogen, can modulate the host response under hypoxia and anoxia.