Actinomyces israelii has long been recognized as a causative agent of actinomycosis. During the past 3 decades, a large number of novel Actinomyces species have been described. Their detection and ...identification in clinical microbiology laboratories and recognition as pathogens in clinical settings can be challenging. With the introduction of advanced molecular methods, knowledge about their clinical relevance is gradually increasing, and the spectrum of diseases associated with Actinomyces and Actinomyces-like organisms is widening accordingly; for example, Actinomyces meyeri, Actinomyces neuii, and Actinomyces turicensis as well as Actinotignum (formerly Actinobaculum) schaalii are emerging as important causes of specific infections at various body sites. In the present review, we have gathered this information to provide a comprehensive and microbiologically consistent overview of the significance of Actinomyces and some closely related taxa in human infections.
Periodontitis is an infection-driven inflammatory disease in which the composition of biofilms plays a significant role. Dental plaque accumulation at the gingival margin initiates an inflammatory ...response that, in turn, causes microbial alterations and may lead to drastic consequences in the periodontium of susceptible individuals. Chronic inflammation affects the gingiva and can proceed to periodontitis, which characteristically results in irreversible loss of attachment and alveolar bone. Periodontitis appears typically in adult-aged populations, but young individuals can also experience it and its harmful outcome. Advanced disease is the major cause of tooth loss in adults. In addition, periodontitis is associated with many chronic diseases and conditions affecting general health.
is recognized as one of the core anaerobic genera in the oral microbiome. In addition, members of this genus belong to microbial communities of the gastrointestinal and respiratory tracts. Several ...novel
species, most of them of oral origin, have been described, but limited knowledge is still available of their clinical relevance.
is among the anaerobic commensals on oral mucosae from early months of life onward, and other early colonizing
species in the oral cavity include
and
. Oral
species get constant access to the gastrointestinal tract via saliva swallowing and to lower airways via microaspiration. At these extra-oral sites, they play a role as commensals but also as potentially harmful agents on mucosal surfaces. The aim of this narrative review is to give an updated overview on the involvement of oral
species in gastrointestinal and respiratory health and disease.
organisms reside on mucosal surfaces of the oropharynx and the genitourinary tract. Polymicrobial infections with
organisms are increasingly being reported in the literature. Since these infections ...differ from classical actinomycosis, lacking of specific clinical and imaging findings, slow-growing
organisms can be regarded as contaminants or insignificant findings. In addition, only limited knowledge is available about novel
species and their clinical relevance. The recent reclassifications have resulted in the transfer of several
species to novel genera
,
,
,
, or
. The spectrum of diseases associated with specific members of
and these related genera varies. In human infections, the most common species are Actinomyces
,
, and
, which are typical inhabitants of the mouth, and
,
, and
. In this narrative review, the purpose was to gather information on the emerging role of specific organisms within the
and related genera in polymicrobial infections. These include
in pulmonary infections,
in brain abscesses and infections in the lower respiratory tract,
in skin-related infections,
in necrotizing fasciitis and skin abscesses, and
in infected tissues around prostheses and devices. Increased understanding of the role of
and related species in polymicrobial infections could provide improved outcomes for patient care. Key messages Due to the reclassification of the genus, many former
species belong to novel genera
,
,
,
, or
.Some of the species play emerging roles in specific infection types in humans.Increasing awareness of their clinical relevance as an established or a putative pathogen in polymicrobial infections brings about improved outcomes for patient care.
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.
Background and Aims
The scope of this working group was to review (1) ecological interactions at the dental biofilm in health and disease, (2) the role of microbial communities in the pathogenesis of ...periodontitis and caries, and (3) the innate host response in caries and periodontal diseases.
Results and Conclusions
A health‐associated biofilm includes genera such as Neisseria, Streptococcus, Actinomyces, Veillonella and Granulicatella. Microorganisms associated with both caries and periodontal diseases are metabolically highly specialized and organized as multispecies microbial biofilms. Progression of these diseases involves multiple microbial interactions driven by different stressors. In caries, the exposure of dental biofilms to dietary sugars and their fermentation to organic acids results in increasing proportions of acidogenic and aciduric species. In gingivitis, plaque accumulation at the gingival margin leads to inflammation and increasing proportions of proteolytic and often obligately anaerobic species. The natural mucosal barriers and saliva are the main innate defence mechanisms against soft tissue bacterial invasion. Similarly, enamel and dentin are important hard tissue barriers to the caries process. Given that the present state of knowledge suggests that the aetiologies of caries and periodontal diseases are mutually independent, the elements of innate immunity that appear to contribute to resistance to both are somewhat coincidental.
Large, general population-based data on carriage rates of periodontal pathogens hardly exist in the current literature. The objectives of the present study were to examine the salivary detection of ...Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, Campylobacter rectus, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Treponema denticola in a representative sample of the adult population living in southern Finland and to clarify which determinants are associated with the presence of these pathogens in saliva. 16S rRNA-based PCR methods with species-specific primers were employed to determine the presence of the six target bacteria in stimulated saliva samples, which were available from 1,294 subjects aged >=30 years. The age group, gender, level of education, marital status, smoking history, number of teeth, and number of teeth with deepened pockets were included in the statistical analysis. In general, the carriage of periodontal pathogens was common, since at least one of the examined pathogens was found in 88.2% of the subjects. In descending order, the total detection rates were 56.9%, 38.2%, 35.4%, 31.3%, 20.0%, and 13.9% for T. forsythensis, T. denticola, P. gingivalis, C. rectus, A. actinomycetemcomitans, and P. intermedia, respectively. Age per se was strongly associated with the carriage of P. gingivalis (P = 0.000), and the level of education with that of T. denticola (P = 0.000). There was an association between the number of teeth with deepened pockets and carriage of P. gingivalis (P = 0.000), P. intermedia (P = 0.000), T. denticola (P = 0.000), and A. actinomycetemcomitans (P = 0.004). The data suggest that distinct species have a different carriage profile, depending on variables such as age, educational level, and periodontal status.
Reproducibility and quality of MALDI-TOF MS spectra are critical in the identification process, however, information on the factors affecting the identification scores are scarce. Here, we studied ...the influence of various factors during the identification process of human oral Capnocytophaga species. The influence of two incubation times, plate-spotting reproducibility of two examiners, extraction technique, storage period of plates, and different laser repetition rates on the quality of MALDI-TOF MS identification of 34 human Capnocytophaga strains (including C. gingivalis, C. granulosa, C. haemolytica, C. leadbetteri, C. ochracea, C. sputigena, and Capnocytophaga genospecies AHN8471) was examined. The identification rate did not show a significant difference (P = 0.05) between the two incubation times, except that C. haemolytica needed a longer incubation time to be recognized at the genus level. The reproducibility of spotting between two examiners was ensured by following the manufacturer's instructions. At the species level, formic acid extraction improved the identification of species with limited representation in the database, such as C. haemolytica and C. granulosa. The storage of plates for one week decreased the identification scores. No significant difference (P = 0.39) was observed between the 60 Hz and 120 Hz laser repetition rates for identifying Capnocytophaga species to the genus or species level. In conclusion, the MALDI TOF MS offers a reliable Capnocytophaga identification after following the universal protocol, while the formic acid extraction is restricted to species with a limited number of strains in the database.
•Following the universal protocol of anaerobes ensured the quality of Capnocytophaga identification.•Incubation time and related colony differences did not affect the identification rate.•Formic acid extraction is necessary for C. haemolytica and C. granulosa identification.•Expanding MALDI Biotyper database to cover all Capnocytophaga spp. is still needed.
Matrix metalloproteinase-8 is a promising candidate biomarker for oral fluid (gingival crevicular fluid, peri-implant sulcular fluid and saliva) and mouthrinse chair-side/point-of-care diagnostics to ...predict, diagnose and determine the progressive phases of episodic periodontitis and peri-implantitis, as well as to monitor the treatments and medications. Matrix metalloproteinase-8 can be used alone or together with interleukin-1beta and Porphyromonas gingivalis to calculate cumulative risk score at the subject level as a successful diagnostic tool, especially in large-scale public health surveys, in which a thorough periodontal examination is not feasible.
Background
Monocyte chemoattractant protein‐1 (MCP‐1), macrophage migration inhibitory factor (MIF), and fractalkine are chemokines that are expressed by a variety of cell types to regulate ...macrophage inflammatory response. The aim of the study was to examine the effects of periodontitis and rheumatoid arthritis (RA) on their serum and salivary concentrations.
Methods
Adults with either periodontitis (P, n = 21), or with rheumatoid arthritis (RA, n = 23), or with both diseases (RA+P, n = 23) were included in the study. Systemically and periodontally healthy individuals (n = 22) served as controls. Saliva and serum samples were collected from all participants before the medical and periodontal examinations. Salivary and serum MCP‐1, MIF, and fractalkine concentrations were measured by the Luminex technique. Total salivary protein levels were determined by the Bradford assay.
Results
Salivary MCP‐1, MIF, and fractalkine concentrations were elevated in both RA groups (RA+P and RA) in comparison with systemically healthy controls. As related to total salivary protein levels, higher MCP‐1 (P = 0.003) and fractalkine (P = 0.045) concentrations were found in controls compared with the P group. In serum, MCP‐1 concentrations in the RA+P group were higher (P = 0.003) than those of group P. Elevated serum fractalkine concentrations were observed in both periodontitis groups (RA+P, P = 0.014; and P, P = 0.013) compared with controls.
Conclusions
In RA, MCP‐1, MIF, and fractalkine concentrations are elevated in saliva. These chemokines may disrupt oral macrophage responses and potentially take part in the interaction between periodontitis and RA.
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