Actinotignum schaalii subcutaneous abscesses in a patient with hidradenitis suppurativa: Case report and literature review.

Actinotignum schaalii (formerly Actinobaculum schaalii) is a Gram-positive, facultative anaerobic rod that is typically involved in urinary tract infections in elderly patients or those with underlying urological pathologies. In contrast, abscess formation caused by A. schaalii is very rare. We present a case of multiple abscesses in the perineal area in a young patient with hidradenitis suppurativa associated with A. schaalii and Prevotella melaninogenica and review the relevant literature on the topic.

Evaluation of the microbiota of primary endodontic infections using checkerboard DNA-DNA hybridization.

BACKGROUND/AIMS: The aim of this study was to evaluate the composition of the microbiota of primary endodontic infections in 111 selected cases of single-rooted teeth with necrotic pulp. METHODS: Samples were collected from the root canals using #15 Hedströen-type files and two sterile paper points, which were introduced 1 mm short of the apical foramen. The presence, levels, and proportions of 40 different bacterial species in each sample were determined using DNA probes and checkerboard DNA-DNA hybridization techniques. RESULTS: The mean number of species per sample was 22. Enterococcus faecalis (89.3%), Campylobacter gracilis (89.3%), Leptotrichia buccalis (89.3%), Neisseria mucosa (87.5%), Prevotella melaninogenica (86.6%), Fusobacterium nucleatum ssp. vincentii (85.7%), Eubacterium saburreum (75.9%), Streptococcus anginosus (75%), and Veillonella parvula (74.1%) were the most prevalent species. The species found in highest mean counts (over 10(5)) were F. nucleatum ssp. vincentii (13.14 x 10(5)), E. saburreum (5.67 x 10(5)), E. faecalis (5.38 x 10(5)), N. mucosa (4.19 x 10(5)), V. parvula (3.63 x 10(5)), C. gracilis (3.46 x 10(5)), Treponema socranskii (3.34 x 10(5)), Porphyromonas endodontalis (2.96 x 10(5)), Porphyromonas gingivalis (2.85 x 10(5)), Micromonas micros (2.81 x 10(5)), Prevotella nigrescens (2.68 x 10(5)) and Fusobacterium nucleatum ssp. nucleatum (2.64 x 10(5)). Most of these species were also found in high proportions. CONCLUSIONS: Our results suggest that several bacterial species considered to be oral pathogens seem to be implicated in the etiology of primary endodontic infections.

Phototargeting oral black-pigmented bacteria.

We have found that broadband light (380 to 520 nm) rapidly and selectively kills oral black-pigmented bacteria (BPB) in pure cultures and in dental plaque samples obtained from human subjects with chronic periodontitis. We hypothesize that this killing effect is a result of light excitation of their endogenous porphyrins. Cultures of Prevotella intermedia and P. nigrescens were killed by 4.2 J/cm2, whereas P. melaninogenica required 21 J/cm2. Exposure to light with a fluence of 42 J/cm2 produced 99% killing of P. gingivalis. High-performance liquid chromatography demonstrated the presence of various amounts of different porphyrin molecules in BPB. The amounts of endogenous porphyrin in BPB were 267 (P. intermedia), 47 (P. nigrescens), 41 (P. melaninogenica), and 2.2 (P. gingivalis) ng/mg. Analysis of bacteria in dental plaque samples by DNA-DNA hybridization for 40 taxa before and after phototherapy showed that the growth of the four BPB was decreased by 2 and 3 times after irradiation at energy fluences of 4.2 and 21 J/cm2, respectively, whereas the growth of the remaining 36 microorganisms was decreased by 1.5 times at both energy fluences. The present study suggests that intraoral light exposure may be used to control BPB growth and possibly benefit patients with periodontal disease.

A hemagglutinating variant of Prevotella melaninogenica isolated from the oral cavity.

Strains resembling Prevotella melaninogenica were isolated from healthy subjects and patients with periodontal disease and were identified using: a 5-test phenotypic screen; commercial identification kits; and a 16S rRNA-based polymerase chain reaction (PCR) method. Eleven clinical isolates closely resembling P. melaninogenica, and all from patients with periodontitis, were able to agglutinate erythrocytes. In the electron microscope, hemagglutinating isolates showed fimbria-like structures, that were not seen on non-hemagglutinating isolates. Some strains were further classified with PCR-restriction fragment-length polymorphism (RFLP) of 16S rRNA genes. Amplified 16S rDNA was digested using five different endonucleases, separated with agarose gel electrophoresis, stained and photographed. Photographs were then scanned, digitized and a distance matrix calculated using Dice coefficient, where the presence or absence of a band was used as a character. The distance matrix was plotted as a phenogram. At 70% similarity six clusters were seen. Type strains of separate Prevotella species did not fall into any cluster. Hemagglutinating isolates fell into three clusters: four clustered with the type strains of P. melaninogenica and Prevotella veroralis; four with other P. melaninogenica isolates and two hemagglutinating isolates clustered together Prevotella loescheii. The PCR-RFLP results showed that the hemagglutinating strains did not form a homogenous group inside the Prevotella genus.

Rapid presumptive identification of human black pigmented Bacteroides species.

A simple and reliable technique is described for the rapid presumptive identification of black pigmented Bacteroides species of human origin. This method involved a microtitration technique that detected the hydrolysis of specific chromogenic enzyme substrates and haemagglutination of sheep erythrocytes. Pure cultures of black pigmented Bacteroides strains, representing the eight human species, were successfully differentiated and identified within 4 h by the identification scheme developed with this method. This is a highly reproducible method and the scheme should be useful in laboratories lacking the sophisticated equipment often needed for the identification of black pigmented Bacteroides.

[The correlation of black-pigmented bacteroides spp to symptoms associated with apical periodontitis].

The quantitative analysis of the incidence of black-pigmented Bacteroides (B.P.B.) spp. in 80 human dental root canal infections (56 with acute symptoms and 24 clinically asymptomatic) in 79 adults were studied. Altogether 101 strains including 7 species of B. P. B. were identified. It was found that the infection rate of B. P. B. in symptomatic group (192.86%) was higher than that in asymptomatic group (41.67%). The means of quantity of cultivable B. P. B. (CFU/ml) and percentage of B.P.B. (CFU/ml) in total CFU/ml of bacteria were not significant. But the percentage of asacchrolytic B.P.B. species in B.P.B. positive samples in symptomatic group (73.08%) was higher than that in B.P.B. positive samples in asymptomatic group (40%). These results suggest that there is a close correlation between symptoms and the asacchrolytic species of B. endodontalis and B. gingivalis.

The use of whole-cell DNA probes for the identification of Bacteroides intermedius isolates in a dot blot assay.

Bacteroides intermedius includes two distinct groups of organisms that are phenotypically indistinguishable by conventional methods. These two groups are represented by the type strain of the species ATCC 25611T (B. intermedius type I) and by ATCC 33563 (B. intermedius type II). Members of each group can be distinguished from each other by analysis of the cellular protein composition by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and by DNA-DNA homology studies, because they share less than 40% homology. The purpose of this study was to prepare specific DNA probes for the two groups of Bacteroides intermedius and to test them against field isolates. Whole-cell DNA probes were prepared from B. intermedius types I and II and tested against 253 field strains of Bacteroides which had been identified by conventional phenotypic tests as B. intermedius. Of these, 170 (67%) hybridized with the B. intermedius type I DNA probe, 28 (11%) with the type II, and 23 (9%) failed to react with the B. intermedius probes but did hybridize with either B. melaninogenicus, B. loescheii, or B. corporis whole-cell DNA probes. The 32 (13%) remaining isolates failed to hybridize with any of the five Bacteroides probes or with probes to B. asaccharolyticus, B. buccae, B. buccalis, B. denticola, B. gingivalis, B. oralis, or B. oris. These data demonstrate the usefulness of whole-cell DNA probes for the identification of phenotypically similar or identical field isolates.

Use of the RapID-ANA System to screen for enzyme activities that differ among species of bile-inhibited Bacteroides.

The RapID-ANA System (Innovative Diagnostics Systems, Inc., Atlanta, Ga.) was used to test 102 strains of 14 species of phenotypically similar bile-inhibited Bacteroides from humans. Bacteroides oris, Bacteroides veroralis, Bacteroides buccalis, Bacteroides melaninogenicus, Bacteroides loescheii, and Bacteroides denticola had very similar enzyme activity profiles. Clear differentiation of these six species by the RapID-ANA System was not possible, but tests for arginine aminopeptidase and beta-glucosidase were helpful. Bacteroides oralis, Bacteroides intermedius, Bacteroides corporis, Bacteroides disiens, Bacteroides bivius, Bacteroides gingivalis, Bacteroides asaccharolyticus, and Bacteroides buccae each had unique enzyme activity profiles. No consistent differences in enzyme activities were found between the two DNA homology groups within Bacteroides melaninogenicus, Bacteroides loescheii, or Bacteroides intermedius. Tests for glycine aminopeptidase, alpha-galactosidase, arginine aminopeptidase, alpha-fucosidase, N-acetylglucosaminidase, reduction of triphenyltetrazolium, and production of indole were helpful in the differentiation of the species studied.

Numerical taxonomy of some non-saccharolytic and saccharolytic Bacteroides species.

Various Bacteroides spp. were examined by physiological tests, presence of specific enzymes, antibiotic sensitivity, menaquinone composition and a few miscellaneous tests. The data matrix containing 58 strains and 55 unit characters was examined using Gower's similarity coefficients (SG) and included matching negative character states and multistate characters. The highly saccharolytic strains were separated from the less saccharolytic and non-fermentative strains at the 55% similarity level; while at the slightly higher level of 63% strains of Capnocytophaga (formerly Bact. ochraceus) were recovered as a compact phenon distinct from other saccharolytic species. The phenogram was divided into 6 clusters at 72% similarity level. Most of the 'Bact. fragilis group' of species clustered in one phenon while Bact. melaninogenicus ssp. melaninogenicus, Bact. bivius and a new species, Bact. denticola, formed another group. Another phenon comprised the saccharolytic non-pigmented species closely related to Bact. oralis such as Bact. buccalis and Bact. pentosaceus. The less saccharolytic strains of Bact. melaninogenicus ssp. intemedius and Bact. disiens were recovered in a distinct phenon. The low affinity (less than 55% similarity) between the two subspecies of Bact. melaninogenicus emphasised the need for reclassifying these taxa into separate species. The non-fermentative and very weakly saccharolytic strains formed good taxospecies. The separation of this cluster into three subclusters is in excellent agreement with chemotaxonomic data now available.

Production of phenylacetic acid by Bacteroides melaninogenicus ssp. intermedius serogroup C-1.

The methyl derivatives of broth cultures of black-pigmented Bacteroides were examined by gas chromatography for production of phenylacetic acid. Two serogroups of B. melaninogenicus ssp. intermedius described by Lambe differed in the ability to produce phenylacetate. Serogroup C failed to produce phenylacetic acid while serogroup C-1 produced small amounts of phenylacetate, which contributed 2.2-5.7% to the total nonvolatile acid profile. Holdeman's newly proposed species "B. intermedius" and "B. corporis" correspond to serogroups C and C-1, respectively. These data support the elevation of the two serogroups of B. melaninogenicus ssp. intermedius to species status. Bacteroides gingivalis produced phenylacetate in significantly larger quantities than B. corporis. Bacteroides melaninogenicus ssp. melaninogenicus, "B. melaninogenicus ssp. levii," and B. asaccharolyticus did not produce phenylacetic acid. These results indicate that phenylacetic acid production may be useful in distinguishing "B. corporis" and B. gingivalis from the other black-pigmented Bacteroides.

A bacteriocin typing scheme for Bacteroides.

Epidemiological studies of Bacteroides spp. have been hindered because a suitable typing method is not available. In preliminary studies, 50 strains of Bacteroides were screened against each other for bacteriocin production and sensitivity; 54% of them produced bacteriocin(s) and more than 90% were sensitive to at least one bacteriocin. After calculation of similarity values for these 50 isolates, a typing set of six bacteriocinogenic strains was selected for a typing method based on bacteriocin sensitivity. With this typing set c. 90% of strains could be typed and tests of reproducibility suggested that acceptable accuracy and discrimination could be obtained without applying any one-reaction or two-reaction difference rules. Isolates from four hospitals gave a similar spectrum of typing patterns with 18 bacteriocin types being demonstrated. There was not correlation between bacteriocin type and species of Bacteroides.

The direct immunofluorescence in the presumptive identification of Bacteroides species.

Two kits containing fluorescein labeled-polyvalent antisera to Bacteroides fragilis, Bacteroides distasonis, Bacteroides ovatus, Bacteroides thetaiotaomicron, Bacteroides vulgatus (Fluoretec-F) and to Bacteroides melaninogenicus subsp. melaninogenicus and intermedius and to Bacteroides asaccharolyticus (non-oral strains) (Fluoretec-M) were evaluated for the identification of the respective organisms in bacterial cultures and clinical specimens. In both cases immunofluorescent tests were compared to the bacteriological data. The results clearly demonstrated that Fluoretec-F has a specificity 97% and a sensitivity 96%. The corresponding values for Fluoretec-M were 99% and 87.5% respectively, either clinical specimens or pure cultures were examined. The presence of aerobic of facultative anaerobic bacteria and obligate anaerobic bacteria other than those to which antisera were included in the test kits did not seem to influence the test result. No cross-reactivity between Fluoretec-F and -M were observed. Also, no positive fluorescence was obtained when other anaerobic bacteria than Bacteroides spp. were tested. The same was also the case with various aerobic or facultative anaerobic bacteria. The use of Fluoretec-F and -M is considered as a useful tool for the early accurate identification of the Bacteroides species mentioned, which may serve as a guide for an appropriate prompt therapy which is especially needed in serious anaerobic infections.