Capnocytophaga haemolytica sp. nov. and Capnocytophaga granulosa sp. nov., from human dental plaque

A Co-Association of Streptococcus mutans and Veillonella parvula/dispar in Root Caries Patients and In Vitro Biofilms

Root caries in geriatric patients is a growing problem as more people are maintaining their natural teeth into advanced age. We determined the levels of various bacterial species previously implicated in root caries disease or health using quantitative real-time PCR in a pilot study of 7 patients with 1 to 4 root caries lesions per person. Levels of 12 different species on diseased roots compared to healthy (contralateral control) roots were measured. Four species were found at significantly higher levels on diseased roots (Streptococcus mutans, Veillonella parvula/dispar, Actinomyces naeslundii/viscosus, and Capnocytophaga granulosa) compared across all plaque samples. The level of colonization by these species varied dramatically (up to 1,000-fold) between patients, indicating different patients have different bacteria contributing to root caries disease. Neither of the two species previously reported to correlate with healthy roots (C. granulosa and Delftia acidovorans) showed statistically significant protective roles in our population, although D. acidovorans showed a trend toward higher levels on healthy teeth (P = 0.08). There was a significant positive correlation between higher levels of S. mutans and V. parvula/dispar on the same diseased teeth. In vitro mixed biofilm studies demonstrated that co-culturing S. mutans and V. parvula leads to a 50 to 150% increase in sucrose-dependent biofilm mass compared to S. mutans alone, depending on the growth conditions, while V. parvula alone did not form in vitro biofilms. The presence of V. parvula also decreased the acidification of S. mutans biofilms when grown in artificial saliva and enhanced the health of mixed biofilms.

Capnocytophaga periodontitidis sp. nov., isolated from subgingival plaque of periodontitis patient

Two carbon dioxide-requiring, gliding, Gram-stain-negative strains, designated p1a2^T and 051621, were isolated from subgingival plaque in association with severe periodontitis. The 16S rRNA gene sequence analysis revealed that they represented members of the genus Capnocytophaga and had less than 96.4 % pairwise similarity with species with validly published names in this genus. The whole-genome sequences of those strains had less than 91.9 % average nucleotide identity and 48.4 % digital DNA-DNA hybridization values with the other type strains of species of the genus Capnocytophaga, both below the species delineation threshold. The results of pan-genomic analysis indicated that p1a2^T and 051621 shared 765 core gene families with the other ten species in this genus, and the numbers of strain-specific gene families were 493 and 455, respectively. The major fatty acids were iso-C_15 : 0 and C_16 : 0. A combination of phenotypic, chemotaxonomic, phylogenetic and genotypic data clearly indicate that p1a2^T and 051621 should be considered to represent a novel species of the genus Capnocytophaga, for which the name Capnocytophaga periodontitidis sp. nov. is proposed. The type strain is p1a2^T (=CGMCC 1.17337^T=JCM 34126^T).

Isolation and Characterization of Capnocytophaga bilenii sp. nov., a Novel Capnocytophaga Species Detected in a Gingivitis Subject

Capnocytophaga species are commensal gliding bacteria that are found in human and animal oral microbiota and are involved in several inflammatory diseases, both in immunocompromised and immunocompetent subjects. This study contributes to increased knowledge of this genus by characterizing a novel species isolated from a dental plaque sample in a male with gingivitis. We investigated morphological and chemotaxonomic characteristics using different growth conditions, temperature, and pH. Cellular fatty acid methyl ester (FAME) analysis was employed with gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI), and digital DNA–DNA hybridization (dDDH) relatedness were performed. The Marseille-Q4570^T strain was found to be a facultative aerobic, Gram-negative, elongated, round-tipped bacterium that grew at 25–56 °C and tolerated a pH of 5.5 to 8.5 and an NaCl content ranging from 5 to 15 g/L. The most abundant fatty acid was the branched structure 13-methyl-tetradecanoic acid (76%), followed by hexadecanoic acid (6%) and 3-hydroxy-15-methyl-hexadecanoic acid (4%). A 16S rDNA-based similarity analysis showed that the Marseille-Q4570^T strain was closely related to Capnocytophaga leadbetteri strain AHN8855^T (97.24% sequence identity). The OrthoANI and dDDH values between these two strains were, respectively, 76.81% and 25.6%. Therefore, we conclude that the Marseille-Q4570^T strain represents a novel species of the genus Capnocytophaga, for which the name Capnocytophaga bilenii sp. nov. is proposed (=CSUR Q4570).

The Herbal Formula CWBSD Improves Sleep Quality Dependent on Oral Microbial Type and Tongue Diagnostic Features in Insomnia

Cheonwangbosim-dan (CWBSD) is a traditional Korean herb formula that has been widely prescribed for insomnia patients with a heart-yin deficiency (HYD) pattern. Several studies have reported that heart function and insomnia are interrelated, and few have explored associations between insomnia, oral microbiota, and tongue diagnosis. This study aimed to evaluate the effects of CWBSD on primary insomnia, tongue diagnosis, and oral microbiota. At baseline, 56 patients with primary insomnia were assigned to two groups, a HYD group and a non-HYD (NHYD) group and they took CWBSD for 6 weeks. During the study, Pittsburgh Sleep Quality Indices (PSQIs) and Insomnia Severity Indices (ISIs) decreased significantly in both groups. However, the PSQI reduction observed in the HYD group was greater than in the NHYD group and sleep times increased only in the HYD group. As sleep quality improved, the amount of tongue coating increased at the posterior tongue, where heart function appears. At baseline, the HYD and NHYD group had a specific oral microbiota (Veillonella at genus level), but no significant change was observed after taking CWBSD. Additionally, subjects were divided into two oral microbiota types ("orotypes"). The genera Prevotella, Veillonella, or Neisseria were abundant in each orotype. The reduction in PSQI in orotype 1 during the 6-week treatment period was greater than in orotype 2. In conclusion, this study shows that CWBSD could be used to treat primary insomnia in patients with a HYD pattern as determined using tongue diagnosis and oral microbiota distributional patterns.

Molecular identification of Capnocytophaga species from the oral cavity of patients with chronic periodontitis and healthy individuals

Introduction:

Capnocytophaga species are recognized as part of human oral microbiota and implicated as periodontal pathogens associated with various periodontal diseases. The three original Capnocytophaga species - Capnocytophaga ochracea, Capnocytophaga sputigena and Capnocytophaga gingivalis were initially isolated from periodontitis in adults, but subsequent studies demonstrated their presence also at periodontally healthy sites in both children and adults. Their association with periodontal disease is a matter of controversy. Considering the differing virulence features of the respective isolate, it is crucial to identify these isolates to species level.

Aims:

The aim of this study is to investigate the prevalence of Capnocytophaga species by polymerase chain reaction (PCR) through restriction fragment length polymorphism in healthy individuals and patients with periodontal disease.

Material and Methods:

The study included a total of 300 individuals, 100 each with Gingivitis, Chronic periodontitis, and Healthy individuals. The plaque samples were collected using sterile curette in reduced transport fluid. DNA extraction was carried out for PCR analysis.

Results:

Of 300 individuals, Capnocytophaga species were identified from 237 (79%) participants in all groups. The prevalence was statistically analyzed using Chi-square test. The prevalence was more in males in gingivitis and healthy individuals (42% and 49% respectively), and females in periodontitis (40%). C. ochracea was observed in a higher proportion (36.33%), followed by C. granulosa (32.66%) and C. gingivalis (10%). They were identified more in the age group of 30–40 years in gingivitis and periodontitis, (30 and 21 individuals, respectively) and 39 individuals in 18–29 years in healthy individuals. They were present in 87% in healthy individuals, 77% in gingivitis and 73% in periodontitis.

Conclusion:

Capnocytophaga species are commonly present in healthy individuals and may be associated with periodontal disease. There is a need for further study to know the prevalence of other species of Capnocytophaga in health and disease.

Capnocytophaga felis sp. nov. isolated from the feline oral cavity

Four strains, KC07070^T, KC07105, 11 025B-8C and 11 026B-8-C, were isolated from the oral cavity of cats in 2007 or 2011 in Japan. These strains were Gram-stain-negative rods, exhibited gliding motility, grew in air with 5 % CO₂ and showed catalase and oxidase activity. The sequences of 16S rRNA genes of the four strains were 100 % identical. Additionally, the sequences of 16S rRNA genes of KC07070^T had identity to those of the type strains of Capnocytophaga canimorsus (97.7 %), Capnocytophaga cynodegmi (97.8 %) and Capnocytophaga canis (97.4 %) and 91.2-93.8% identity to those of other species of the genus Capnocytophaga. The major cellular fatty acids of KC07070^T were iso-C_15 : 0 (56.2 %) and summed feature 11 (14.9 %). The G+C content of the DNA from KC07070^T was 35.6 mol%, and the genome size was 2.88 Mbp. KC07070^T had digital DNA-DNA hybridization (dDDH) values of 26.2-27.6% and average nucleotide identity (ANI) values of 75.4-83.3 % to the type strains of the closest relatives, C. canimorsus, C. cynodegmi and C. canis. These results of phylogenetic analysis of 16S rRNA gene sequence, cellular fatty acids compositions and dDDH and ANI values indicate that strain KC07070^T represents a novel species, for which we propose the name Capnocytophaga felis sp. nov., with type strain KC07070^T (=JCM 32681^T=DSM 107251^T).

Characterization of three strains of Capnocytophaga canis isolated from patients with sepsis

Capnocytophaga canimorsus and Capnocytophaga cynodegmi, both commensal bacteria in the oral cavities of dogs and cats, are zoonotic pathogens. In particular, C. canimorsus causes sepsis and fatal septic shock. Recently, a novel Capnocytophaga species, C. canis, was isolated from the oral cavities of healthy dogs. It is reportedly oxidase-negative and therefore considered avirulent in humans. In the present study, three strains of C. canis were isolated from Japanese patients with sepsis. All three strains, HP20001, HP33001 and HP40001, were oxidase-positive. Nucleotide sequence identities of the 16S rRNA gene of the three strains to the C. canimorsus type strain ATCC35979, C. cynodegmi type strain ATCC49044 and C. canis type strain LMG29146 were 96.9-97.0%, 96.9-97.0% and 99.7-99.8%, respectively. Multi-locus sequence analysis based on seven house-keeping genes, dnaJ, fumC, glyA, gyrB, murG, trpB and tuf, revealed that the oxidase-positive C. canis strains isolated in Japan and oxidase-negative strains of C. canis from canine oral cavities in Switzerland were clustered in different genetic subgroups. These results indicate that the virulence of C. canis strains in humans is associated with oxidase activity.

Twelve Complete Reference Genomes of Clinical Isolates in the Capnocytophaga Genus

We report here 1 near-complete genome sequence and 12 complete genome sequences for clinical Capnocytophaga isolates. Total read coverages ranged from 211× to 737×, and genome sizes ranged from 2.41 Mb to 3.10 Mb. These genomes will enable a more comprehensive taxonomic evaluation of the Capnocytophaga genus.

Citreitalea marina gen. nov., sp. nov., a novel member of the family Flavobacteriaceae isolated from a marine red alga and emended description of the genus Gangjinia

A Gram-negative, strictly aerobic, pale-yellow pigmented, rod-shaped bacterium designated A4O-5(T) was isolated from a red coloured marine alga (Chondrus ocellatus Holmes). Phylogenetic analyses based on the 16S rRNA gene sequence indicated that the new strain was affiliated with the family Flavobacteriaceae and shared approximately 90 % sequence similarity with Leptobacterium flavescens YM3-0301(T) and Gangjinia marincola GJ16(T). The strain could be differentiated phenotypically from the related members of the family Flavobacteriaceae. The major fatty acids of strain A4O-5(T) were identified as iso-C15:0, iso-C17:0 3-OH and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). A complex polar lipid profile was present consisting of phosphatidylethanolamine, an unidentified phospholipid, three unidentified amino lipids and an unidentified lipid. The DNA G+C content of the strain was determined to be 41.9 mol% and the major respiratory quinone was identified as menaquinone 6 (MK-6). From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel genus in the family Flavobacteriaceae, for which the name Citreitalea marina gen. nov., sp. nov. is proposed. The type strain of C. marina is A4O-5(T) (=KCTC 32483(T)=NBRC 109918(T)).

Integrating next-generation sequencing and traditional tongue diagnosis to determine tongue coating microbiome

Tongue diagnosis is a unique method in traditional Chinese medicine (TCM). This is the first investigation on the association between traditional tongue diagnosis and the tongue coating microbiome using next-generation sequencing. The study included 19 gastritis patients with a typical white-greasy or yellow-dense tongue coating corresponding to TCM Cold or Hot Syndrome respectively, as well as eight healthy volunteers. An Illumina paired-end, double-barcode 16S rRNA sequencing protocol was designed to profile the tongue-coating microbiome, from which approximately 3.7 million V6 tags for each sample were obtained. We identified 123 and 258 species-level OTUs that were enriched in patients with Cold/Hot Syndromes, respectively, representing "Cold Microbiota" and "Hot Microbiota". We further constructed the tongue microbiota-imbalanced networks associated with Cold/Hot Syndromes. The results reveal an important connection between the tongue-coating microbiome and traditional tongue diagnosis, and illustrate the potential of the tongue-coating microbiome as a novel holistic biomarker for characterizing patient subtypes.

Aortic valve endocarditis by Capnocytophaga haemolytica

We report a case of a 51-year-old patient with suspected prosthetic valve endocarditis. Capnocytophaga haemolytica was isolated in blood cultures and the repeated echocardiograms showed growth of vegetations and disruption of the proximal prosthetic valve suture line with progressive aortic regurgitation. The patient underwent a root debridement and replacement with a stentless bioprosthesis.

Antimicrobial treatment of Capnocytophaga infections

Capnocytophaga spp. are normal inhabitants of the oropharyngeal flora. They are also involved in periodontal diseases or animal bites, complicated by septicaemia with dissemination to a great variety of sites, both in immunocompetent and immunocompromised hosts. This review will focus on their pathogenesis, spectrum of clinical infections and susceptibility to disinfectants and antibiotics. The spread of beta-lactamase-producing strains limits the use of beta-lactams as first-line treatments, underlying the necessity to test the in vitro susceptibility of clinical strains. Many antimicrobial treatments have been used, despite an absence of randomised studies and guidelines regarding the duration of treatment according to infected sites. Imipenem/cilastatin, clindamycin or beta-lactamase inhibitor combinations are always effective and their use can be recommended in all infections.

Capnocytophaga in the dental plaque of immunocompromised children with cancer

OBJECTIVES

(i) To compare the prevalence and levels of Capnocytophaga, a known systemic pathogen in immunocompromised patients, in the dental plaque of healthy children and children with cancer, and (ii) to determine the susceptibility of strains isolated from cancer patients to a range of antibiotics.

PATIENTS AND METHODS

Thirty-one children with cancer undergoing a first course of immunosuppressive chemotherapy and 30 healthy control children were included in the study. Samples were collected on days 0, 7, 14, and 21 of the cure (and equivalent dates in controls). Susceptibility to antibiotics was tested using an agar dilution method and galleries with predefined concentrations of selected antibiotics.

RESULTS

There was a significant drop in the total anaerobic cultivable flora on day 14 and in the prevalence of Capnocytophaga on days 14 and 21 in the children with cancer. The proportion of Capnocytophaga in the anaerobic flora, however, was high in certain cancer patients. Beta-lactam/beta-lactamase inhibitor combinations, imipenem, clindamycin, and tetracycline were the most effective against Capnocytophaga.

CONCLUSION

This study showed that Capnocytophaga decreased in prevalence and proportion in the dental plaque of cancer patients during chemotherapy but became predominant in some cases. It is recommended that imipenem or beta-lactam/beta-lactamase inhibitor combinations be used to treat Capnocytophaga bacteraemia.

Isolation and characterization of aminopeptidase from Capnocytophaga granulosa ATCC 51502

There is evidence that enzymes from the genus Capnocytophaga play a role in dental calculus formation. Although most of the species in the genus produce aminopeptidases, there is a paucity of data on the purification and characterization of the enzyme, except in the case of Capnocytophaga gingivalis. The aim of this study was to purify aminopeptidase from culture supernatant of Capnocytophaga granulosa ATCC 51502, a new species of the genus. Purification was performed using ammonium sulfate fractionation and two chromatographic steps. The aminopeptidase was purified 158,433-fold with a yield of 12.0%. The enzyme appeared to be a trimer with a molecular mass of 270 kDa. The optimal pH of the aminopeptidase was 6.5 and its activity was completely inhibited by incubation at 50 degrees C for 10 min. The enzyme showed maximum specificity for basic amino acids (Arg and Lys) and also hydrolyzed noncharged amino acids (Met, Leu and Ala). Ca(2+), Zn(2+) and Fe(3+) activated the enzyme, while EDTA, Ag(+), Hg(+) and Cu(2+) inhibited it. These results suggest that aminopeptidase of C. granulosa is different from that of C. gingivalis but similar to aminopeptidase B.

Capnocytophaga granulosa and Capnocytophaga haemolytica: novel species in subgingival plaque

BACKGROUND

The oral cavity accommodates one of the most diverse microfloras in the human body. Knowledge of this microflora, and of the periodontal microflora in particular, proves crucial towards an understanding of the bacterial-host interactions which lead to the development of infectious inflammatory periodontal diseases. Capnocytophaga species have been implicated as putative periodontal pathogens. To date, only 3 members of this genus (C. gingivalis, C. ochracea and C. sputigena) have been isolated from subgingival plaque.

AIM

This communication reports the isolation of 2 recently-speciated strains, namely C. granulosa and C. haemolytica, from subgingival plaque collected from adult periodontitis patients.

MATERIAL AND METHODS

Subgingival plaque was collected from 29 patients with chronic adult periodontitis. Plaque samples were inoculated onto fastidious anaerobe agar and incubated anaerobically for 5 days. Routine identification of clinical isolates was performed by 16S rRNA PCR-RFLP analysis, using Cfo I as restriction enzyme and corroborated by 16S rRNA gene sequencing.

RESULTS

16 of 29 patients (55%) tested positive for either C. granulosa and or C. haemolytica. A total of 70 isolates (63 C. granulosa and 7 C. haemolytica) were cultivated from subgingival plaque. 15 (51%) patients tested positive for C. granulosa, and 3 (10%) patients tested positive for C. haemolytica.

CONCLUSION

This is the 1st report which recounts the presence of C. granulosa and C. haemolytica in subgingival plaque. Further research is required to establish the relative proportions of these species subgingivally in health and disease.

DNA-probes for the differentiation of Capnocytophaga species

We designed oligonucleotides to differentiate between the seven currently known Capnocytophaga species. The oligonucleotides were labelled non-radioactively at the 3' end with digoxigenin. The specificity could be demonstrated in a dot-blot hybridization assay by using the type strains, reference strains, and 37 clinical Capnocytophaga isolates as well as 11 representative strains of other taxa as a template. The sensitivity of the assay was calculated with 10(3) bacteria per dot.

Generation of DNA probes for detection of microorganisms by polymerase chain reaction fingerprinting

Identification of medically relevant microorganisms is important for diagnosis, treatment and prevention of infectious diseases. This has initiated the development of a large number of identification and typing techniques based on phenotypic and genetic characteristics. In general, these last mentioned nucleic acid-mediated techniques provide more detailed and consistent information on strain-specific characteristics. However, the development of clinically useful microbial DNA/RNA probes requires nucleotide sequence information and a set of well defined reference organisms for test validation in comparison with the current gold standard. This is a requirement for the development of accurate nucleic acid hybridisation and/or amplification tests. Recently, it has been demonstrated that polymerase chain reaction (PCR)-mediated genetic typing of microorganisms can lead to the immediate isolation of species-specific DNA probes by comparison of DNA fingerprints. This combines the sensitivity of PCR with the specificity of DNA probing without the need to generate nucleic acid sequence information prior to probe development. The implications of this procedure for clinical microbiology and epidemiological surveillance will be discussed. It is shown that specific probes can be developed for various taxonomic levels and that detection and identification can be combined into a single, fast procedure. The versatility and widely applicable principles of this procedure will be highlighted and exemplified by some newly developed tests and a review of the current literature.

Differentiation of human Capnocytophaga species by multilocus enzyme electrophoretic analysis and serotyping of immunoglobulin A1 proteases

As part of a larger taxonomic investigation of the genus Capnocytophaga, 50 strains, including reference strains as well as clinical isolates, were subjected to multilocus enzyme electrophoretic (MLEE) analysis of 12 intracellular metabolic enzymes and characterization of their immunoglobulin A1 (IgA1) proteases by enzyme-neutralizing antibodies raised in rabbits. The dendrogram derived from cluster analysis of the MLEE data discriminated between the five known human Capnocytophaga species and separated the strains into two major divisions. Division A comprised C. gingivalis and C. granulosa strains, and division B comprised C. ochracea, C. sputigena and C. haemolytica strains. Immunoglobulin A1 (IgA1) protease activity, a known feature of C. ochracea, C. sputigena and C. gingivalis, was present in all strains except the type strain of C. haemolytica and two clinical isolates. Inhibition typing of IgA1 proteases of all active strains with enzyme-neutralizing antibodies against protease preparations of the type strains of C. ochracea, C. sputigena and C. gingivalis separated the strains into two major groups identical to the two divisions based on the MLEE data. Thus, the IgA1 proteases of C. granulosa and C. gingivalis seemed to be antigenically similar to one another, and different from the IgA1 proteases of C. ochracea and C. sputigena, which had similar characteristics. The clustering of the clinical isolates based on the MLEE analyses, which was confirmed by the antigenic characterization of IgA1 proteases, was in good agreement with the results of previous studies.