Cellular fatty acid and soluble protein composition of Actinobacillus actinomycetemcomitans and related organisms

Can presence or absence of periodontal pathogens distinguish between subjects with chronic and aggressive periodontitis? A systematic review

OBJECTIVES

The purpose of this study was to determine to what extent the presence or absence of periodontal pathogens can distinguish between subjects with chronic and aggressive periodontitis.

MATERIAL AND METHODS

A systematic review of cross sectional and longitudinal studies providing microbiological data both from patients with chronic periodontitis (ChP) and aggressive periodontitis (AgP) at a subject level. Strict inclusion criteria were applied. The presence or absence of five microorganisms was selected as primary study parameters: Actinobacillus actinomycetemcomitans (AA), Porphyromonas gingivalis (PG), Prevotella intermedia (PI), Bacteroides forsythus (BF), and Campylobacter rectus (CR).

RESULTS

The presence or absence of AA could be evaluated in 11 papers. In seven papers the presence or absence of PG could be analysed. Subject specific data on PI were available from six studies. Two studies could be used regarding the presence or absence of BF, and two regarding CR. Sensitivity and specificity of every microbiological test were individually calculated for each selected study, assuming that the clinical diagnosis of AgP or ChP was the true status the tests attempted to detect. AgP was considered to be the condition of interest and ChP was considered equivalent to 'non-AgP'. Receiver Operator Characteristic (ROC) diagrams were constructed using these data. ROC diagrams indicated the limited discriminatory ability of all of the test parameters to identify subjects with AgP. An additional assessment showed that the highly leukotoxic variant of AA was uniquely associated with patients suffering from aggressive periodontitis. However, in a high proportion of patients diagnosed with AgP the presence of this variant could not be detected.

CONCLUSION

The presence or absence of AA, PG, PI, BF or CR could not discriminate between subjects with AgP from those with ChP.

Routine analysis of short-chain fatty acids for anaerobic bacteria identification using capillary electrophoresis and indirect ultraviolet detection

The diagnosis of anaerobes can be difficult to perform, using classical biochemical tests. Characterization of metabolic end-products such as short-chain fatty acids (SCFA) was often used because of their reproducible biosynthesis. Despite this, SCFA are difficult to study using gas chromatography, due to their high volatility. Furthermore, the treatment of the samples are long and fastidious. Capillary electrophoresis and indirect UV detection (CE-indirect UV) is a well-known analytical method to study inorganic or organic anions. In this work, we validate the analysis of SCFA using CE-indirect UV detection. To do this, we studied the culture media of 98 anaerobic strains for the detection and quantitation of the following acids: succinic, pyruvic, acetic, lactic, propionic, 2-hydroxybutyric, butyric, 2-hydroxyvaleric, isovaleric, isocaproic, and 3-phenylpropionic. We verified that the CE-indirect UV detection analysis of SCFA for taxonomical data can be used as a mean for rapid identification for the study of anaerobes.

Virulence factors of Actinobacillus actinomycetemcomitans

A. actinomycetemcomitans has clearly adapted well to its environs; its armamentarium of virulence factors (Table 2) ensures its survival in the oral cavity and enables it to promote disease. Factors that promote A. actinomycetemcomitans colonization and persistence in the oral cavity include adhesins, bacteriocins, invasins and antibiotic resistance. It can interact with and adhere to all components of the oral cavity (the tooth surface, other oral bacteria, epithelial cells or the extracellular matrix). The adherence is mediated by a number of distinct adhesins that are elements of the cell surface (outer membrane proteins, vesicles, fimbriae or amorphous material). A. actinomycetemcomitans enhances its chance of colonization by producing actinobacillin, an antibiotic that is active against both streptococci and Actinomyces, primary colonizers of the tooth surface. The fact that A. actinomycetemcomitans resistance to tetracyclines, a drug often used in the treatment of periodontal disease, is on the rise is an added weapon. Periodontal pathogens or their pathogenic products must be able to pass through the epithelial cell barrier in order to reach and cause destruction to underlying tissues (the gingiva, cementum, periodontal ligament and alveolar bone). A. actinomycetemcomitans is able to elicit its own uptake into epithelial cells and its spread to adjacent cells by usurping normal epithelial cell function. A. actinomycetemcomitans may utilize these remarkable mechanisms for host cell infection and migration to deeper tissues. A. actinomycetemcomitans also orchestrates its own survival by elaborating factors that interfere with the host's defense system (such as factors that kill phagocytes and impair lymphocyte activity, inhibit phagocytosis and phagocyte chemotaxis or interfere with antibody production). Once the organisms are firmly established in the gingiva, the host responds to the bacterial onslaught, especially to the bacterial lipopolysaccharide, by a marked and continual inflammatory response, which results in the destruction of the periodontal tissues. A. actinomycetemcomitans has at least three individual factors that cause bone resorption (lipopolysaccharide, proteolysis-sensitive factor and GroEL), as well as a number of activities (collagenase, fibroblast cytotoxin, etc.) that elicit detrimental effects on connective tissue and the extracellular matrix. It is of considerable interest to know that A. actinomycetemcomitans possesses so many virulence factors but unfortunate that only a few have been extensively studied. If we hope to understand and eradicate this pathogen, it is critical that in-depth investigations into the biochemistry, genetic expression, regulation and mechanisms of action of these factors be initiated.

Growth medium affects the cellular fatty acid composition of Pasteurellaceae

We studied the cellular fatty acid composition of 10 Actinobacillus (A.) and Pasteurella (P.) reference strains grown on 2 types of agar by the MIDI Microbial Identification System (MIS). A. capsulatus, A. equuli, A. lignieresii, A. ureae, A. dagmatis, P. gallinarum, P. haemolytica, P. multocida, P. pneumotropica biotypes Heyl and Jawetz were grown on GC agar supplemented with ascitic fluid and X and V factor (Levinthal's agar = LA agar) or GC agar supplemented with vitox and hemoglobin (VH agar) on 3 to 7 and 7 to 16 occasions respectively and fatty acid methylester (FAME) profiles were submitted to principal component analysis (PCA). All Pasteurellaceae strains showed FAME profiles typical for the family. Maximum coefficients of variation of the percentage of the 3 major FAMEs 14:0, 16:0, and 16:1 cis were 0.03, 0.03 and 0.03 for Pasteurellaceae strains grown on VH agar and 0.09, 0.17 and 0.09 respectively for strains grown on LA agar. PCA of FAME profiles obtained with growth from LA agar generally did not allow species separation of the Pasteurellaceae but most species were clearly discriminated by PCA when they were grown on VH agar. Our findings indicate that the growth medium had a significant effect on the reproducibility of fatty acid profiling in Pasteurellaceae and that PCA of fatty acid data obtained under standardized growth conditions may discriminate Pasteurellaceae species.

Cellular fatty acid composition, soluble-protein profile, and antimicrobial resistance pattern of Eubacterium lentum

Phenotypic heterogeneity among isolates of Eubacterium lentum has been recognized for many years. To better delineate their taxonomic relatedness, 29 clinical isolates of E. lentum were examined for soluble-protein content, cellular fatty acid profile, and antimicrobial resistance pattern in order to ascertain whether differences in these characteristics could be correlated with differences in biochemical activities. Among 29 isolates we could identify 6 that were different from all the others. These strains were coccobacilli with translucent colonies; they were catalase and H2S negative, not fluorescent under UV light, and susceptible to beta-lactam drugs; growth was not stimulated by arginine; and fatty acid analysis revealed the presence of straight-chain fatty acids. The remainder of the strains, including the type species, were pleomorphic bacilli with speckled colonies and were catalase and H2S positive; all but two were fluorescent under UV light; they were resistant to beta-lactam antibiotics; growth was greatly stimulated by arginine; and they demonstrated saturated branched-chain fatty acids. Our data suggest that E. lentum can be further differentiated into different types.

Recent approaches to the chemotaxonomy of the Actinobacillus-Haemophilus-Pasteurella group (family Pasteurellaceae)

Many members of the Actinobacillus-Haemophilus-Pasteurella group (family Pasteurellaceae) have been misclassified. This article reviews the chemotaxonomic characters that recently have been provided to improve the taxonomy of Pasteurellaceae. These include fatty acids of whole cells, of lipopolysaccharides and of single colonies, together with sugar contents of whole cells, of whole defatted cells, of lipopolysaccharides and of single colonies. This article also reviews taxonomy aided by distribution of proteins in whole cells and outer membranes, distribution of enzymes in outer membrane vesicles and in whole cells, bacteriolysis induced by ethylenediaminetetraacetic acid and hen eggwhite lysozyme and the distribution of respiratory quinones. Furthermore, an overview of characters obtained through studies on genetic transformation, restriction enzyme analysis, restriction fragment length polymorphism, DNA-DNA hybridization, DNA-rRNA hybridization, and 16S rRNA sequencing is given.

Multivariate chemosystematics demonstrate two groups of Actinobacillus actinomycetemcomitans strains

Chemical analysis by us has indicated that Actinobacillus actinomycetemcomitans is not a homogeneous species. The present study used chemometric methods and a multitude of chemical characters to examine this further. Strains were characterized by cell sugar and fatty acid contents, lysis kinetics during EDTA and EDTA plus lysozyme exposure, methylene blue reduction, and API ZYM enzymatic assessment of whole cells and outer membrane vesicles/fragments. In total, 41 quantitative variables were analyzed from each of 9 strains and treated with principal component analysis and soft independent modeling of class analogy. These methods divided A. actinomycetemcomitans into 2 strain groups. One group contained ATCC 33384, ATCC 29522, FDC 2112 and FDC 2043; the other comprised ATCC 29524, ATCC 29523, FDC 2097, FDC 511 and FDC Y4. With an F-test, the groups (classes) of A. actinomycetemcomitans strains could be distinguished at 95% confidence limits. Both groups were distinct from members of the genera Haemophilus and Pasteurella (Haemophilus aphrophilus, Haemophilus paraphrophilus, Haemophilus influenzae, Pasteurella multocida and Pasteurella haemolytica).

Review of chemosystematics: multivariate approaches to oral bacteria and yeasts

There are several problems related to the classification and identification of bacterial and yeast species assigned to the genera Actinobacillus, Haemophilus, Pasteurella, Bacteroides, Prevotella, Porphyromonas, Campylobacter, Wolinella, Treponema, Candida, Torulopsis, and Saccharomyces, most of which belong to the resident oral microflora. The present review was written to demonstrate how multivariate analyses of data on cellular fatty acids, sugars, enzyme activities, and lysis kinetics during ethylenediaminetetraacetic acid (EDTA) and EDTA plus lysozyme treatment can be used to distinguish closely related species of these bacterial and yeast genera. With the exception of the Actinobacillus-Haemophilus-Pasteurella group, fatty acids were more discriminating than sugars. Enzymes from whole cells and outer membrane vesicles also contributed to taxonomic distinction. Apparently, chemosystematics, involving multivariate analyses, is a useful adjunct in oral microbial taxonomy.

Outer membrane proteins of Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus studied by SDS-PAGE and immunoblotting

This investigation characterized and compared outer membrane proteins (OMP) of the closely related Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus by means of SDS-PAGE patterns and reactions on immunoblots with rabbit antiserum against A. actinomycetemcomitans FDC Y4. Reactions with serum from a patient with Papillon Lefévre syndrome (PLS), from whom periodontal wild strains of A. actinomycetemcomitans had been isolated, were also studied. OMP were purified with selective solubilization from lyophilized cells of 10 wild and 4 reference strains of A. actinomycetemcomitans and 4 reference strains of H. aphrophilus. OMP profiles from wild and reference strains of A. actinomycetemcomitans were similar while those from A. actinomycetemcomitans and H. aphrophilus differed. The most prominent difference was absence of a heat modifiable protein in H. aphrophilus strains. Immunoblotting revealed strong common antigens in most strains, including a heat modifiable protein with mol wt 34 kDa, as well as a 29 kDa and a 16.5 kDa protein. Treatment with pronase and sodium periodate confirmed the protein nature of the major OMP antigens.

Characterization of selected gram-negative oral microorganisms by SDS-PAGE

SDS-PAGE analysis of bacterial cell proteins was used to examine a diverse group of oral microorganisms. Most of the species examined, including physiologically similar microorganisms, produced distinct protein patterns which are characterized by the distribution of their major protein bands. The SDS-PAGE system described provides a rapid, simple and standardized identification technique to be used in consort with routine taxonomic procedures.

Protein patterns, serotyping and plasmid DNA profiles in the epidemiologic fingerprinting of Pseudomonas aeruginosa

The epidemiological typing schemes based on serotyping, antibiotic susceptibility pattern, plasmid DNA profile, and protein patterns determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were evaluated for their usefulness in typing clinical isolates of Pseudomonas aeruginosa. The serotypability was lower (45%) than reported in the literature (85-95%). The most commonly found serotypes were O:1 (19%), O:11 (25%), O:6 (35%). The electrophoretic analysis of plasmid DNAs showed plasmids (molecular weight = 1 to greater than 40 megadaltons). Two plasmids of Mr 2 and 38 megadaltons were found in various serotypes. The restriction enzyme analysis of plasmid DNA showed identical DNA fragment patterns among distinct serotypes. The SDS-PAGE protein banding patterns of whole-cell proteins showed homogeneity among the strains. However, analysis of the soluble protein patterns of the strains showed sufficiently distinct protein profiles that can be used to differentiate between various strains. The results of this study demonstrate that the electrophoretic patterns of soluble proteins, in combination with plasmid DNA profile or serotyping, can be of value in the epidemiologic fingerprinting of clinical isolates of Pseudomonas aeruginosa.

Determination of monounsaturated double-bond position and geometry in the cellular fatty acids of the pathogenic bacterium Francisella tularensis

The nonhydroxy fatty acid composition of Francisella tularensis is reported in detail. The double-bond configuration of the monounsaturated acids has been determined by capillary gas chromatography-mass spectrometry of the derivatized fatty acids. The monounsaturated fatty acids detected, in decreasing order of abundance, were 24:1 omega 15c, 18:1 omega 9c, 22:1 omega 13c, 20:1 omega 11c, 16:1 omega 7c, 26:1 omega 17c, and 14:1 omega 7c. The fatty acid profile found in F. tularensis, in particular the double-bond positions, represents a valuable taxonomic characteristic of this pathogenic bacterium.

Actinobacillus actinomycetemcomitans in human periodontal disease

Recent evidence implicates Actinobacillus actinomycetemcomitans in the etiology of localized juvenile periodontitis. This paper reviews the morphological, biochemical and serological charcteristics of A. actinomycetemcomitans, evidence incriminating it as a periodontopathogen, its importance in human nonoral infections, and virulence factors which may be involved in the pathogenesis of A. actinomycetemcomitans infections. A. actinomycetemcomitans is a non-motile, gram-negative, capnophilic, fermentative coccobacillus which closely resembles several Haemophilus species but which does not require X or V growth factors. The organism has been categorized into 10 biotypes based on the variable fermentation of dextrin, maltose, mannitol, and xylose and into 3 serotypes on the basis of heat stable, cell surface antigens. A. actinomycetemcomitans' primary human ecologic niche is the oral cavity. It is found in dental plaque, in periodontal pockets, and buccal mucosa in up to 36% of the normal population. The organism can apparently seed from these sites to cause severe infections throughout the human body such as brain abscesses and endocarditis. There is a large body of evidence which implicates A. actinomycetemcomitans as an important micro-organism in the etiology of localized juvenile periodontitis including: (1) an increased prevalence of the organism in almost all localized juvenile periodontitis patients and their families compared to other patient groups; (2) the observation that localized juvenile periodontitis patients exhibit elevated antibody levels to A. actinomycetemcomitans in serum, saliva and gingival crevicular fluid; (3) the finding that localized juvenile periodontitis can be successfully treated by eliminating A. actinomycetemcomitans from periodontal pockets; (4) histopathologic investigations showing that A. actinomycetemcomitans invades the gingival connective tissue in localized juvenile periodontitis lesions; (5) the demonstration of several pathogenic products from A. actinomycetemcomitans including factors which may: (a) facilitate its adherence to mucosal surfaces such as capsular polysaccharides; (b) inhibit host defense mechanisms including leukotoxin, a polymorphonuclear leukocyte chemotaxis inhibiting factor, and a lymphocyte suppressing factor (c) cause tissue destruction such as lipopolysaccharide endotoxin, a bone resorption-inducing toxin, acid and alkaline phosphatases, collagenase, a fibroblast inhibiting factor and an epitheliotoxin.(ABSTRACT TRUNCATED AT 400 WORDS)

Differentiation between Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus based on carbohydrates in lipopolysaccharide

In the present study, the closely related facultative, Gram-negative rods, Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus, were distinguished taxonomically by means of their carbohydrate composition in phenol-extracted lipopolysaccharide. Both A. actinomycetemcomitans and H. aphrophilus lipopolysaccharide contained rhamnose, fucose, galactose, glucose, L-glycero-D-mannoheptose, galactosamine, and glucosamine. The content of galactose was approximately twice as high in lipopolysaccharide from H. aphrophilus as in lipopolysaccharide from A. actinomycetemcomitans. D-Glycero-D-mannoheptose was detected exclusively in lipopolysaccharide from A. actinomycetemcomitans where it constituted 11.8-16.7% of the sugar content. This aldoheptose may therefore serve as a marker for chemotaxonomic differentiation between A. actinomycetemcomitans and H. aphrophilus. The present study also describes fragmentation of methylheptoside derivatives of trifluoroacetic acid (D-glycero- and L-glycero-D-mannoheptose) from A. actinomycetemcomitans as suggested by mass spectrometry.

Differentiation of Campylobacter species by protein banding patterns in polyacrylamide slab gels

Soluble protein extracts of 37 catalase-positive strains of Campylobacter species were examined by polyacrylamide slab gel electrophoresis (PAGE). Electrophoretic banding patterns showed good correlation with biochemical tests and with available DNA homology data in distinguishing species of Campylobacter but did not differentiate subspecies or biotypes. PAGE patterns indicated that Campylobacter coli is a distinct species. Furthermore, the PAGE patterns indicated that C. jejuni and nalidixic acid-resistant thermophilic Campylobacter species (C. laridis) are each distinct species. The protein banding patterns of C. fetus subsp. venerealis and C. fetus subsp. fetus strains were distinctly different from those of the three thermophilic species.

Cellular fatty acid and soluble protein profiles of oral fusobacteria

We compared the cellular fatty acid and protein content of 43 strains of oral fusobacteria isolated from patients with chronic gingivitis, acute necrotizing ulcerative gingivitis, and juvenile and adult periodontitis, as well as from the stump-tailed macaque, to that of eight reference strains of oral and non-oral Fusobacterium species. A gas-liquid chromatographic examination of trimethylsilyl derivatives of the fatty acid methyl esters revealed n14:0, 3-OH-14:0, n16:0, 16:1, 3-OH-16:0, n18:0, and 18:1 in each of the 51 study strains, and a variable occurrence of 14 other fatty acids. The n16:0 to 3-OH-16:0 ratio distinguished between Fusobacterium nucleatum and the non-oral species Fusobacterium varium, Fusobacterium necrophorum, Fusobacterium russii, Fusobacterium necrogenes, Fusobacterium mortiferum, and Fusobacterium naviforme. The soluble protein content, as determined by polyacrylamide gel electrophoresis, varied considerably among the oral fusobacterial strains studied, and underscored the heterogenous nature of these organisms. "Fingerprinting" of oral fusobacteria may be readily accomplished by polypeptide analysis.

Electrophoretic study of Clostridium species

Polyacrylamide gel electrophoretic analysis of soluble cellular proteins (without sodium dodecyl sulfate) of 70 Clostridium species indicated that the procedure was readily applicable to the differentiation of species in the genus. The protein patterns correlated well with the available DNA homology data and with most accepted differential tests. Results indicated that several earlier names for species were synonyms of those of accepted species and that two accepted species may be synonymous.

Salient Biochemical Characters of Actinobacillus actinomycetemcomitans

A total of 136 strains of Actinobacillus actinomycetemcomitans were studied for 135 features. All isolates were small nonmotile capnophilic gram-negative rods which grew with no requirement of X or V growth factors. They all decomposed hydrogen peroxide, were oxidase-negative and benzidine-positive, reduced nitrate, produced strong alkaline and acid phosphatases, and fermented fructose, glucose and mannose. Variable fermentation results were obtained with dextrin, maltose, mannitol and xylose. Some isolates produced small amounts of gas. Representative strains of Haemophilus aphrophilus were morphologically and biochemically quite similar to A. actinomycetemcomitans. Characters which should prove to be useful to identify and distinguish these two species include catalase reaction. fermentation of lactose, starch, sucrose and trehalose, and resistance to sodium fluoride. This information allows a rapid diagnosis by species and may be helpful in studies of infections involving these organisms.