Characterization of isolates of members of the genus Actinomyces from Marmota himalayana: description of Actinomyces faecalis sp. nov., Actinomyces respiraculi sp. nov., and Actinomyces trachealis sp. nov.

Six novel strains (ZJ34T, ZJ561, ZJ750T, ZJ1629, zg-993T and zg-987) isolated from faeces and respiratory tracts of Marmota himalayana from the Qinghai-Tibet Plateau of PR China were characterized comprehensively. The results of analyses of the 16S rRNA gene and genome sequences indicated that the six strains represent three novel species of the genus Actinomyces, and are closely related to Actinomyces urogenitalis DSM 15434T (16S rRNA gene sequences similarities, 94.9-98.7 %), Actinomyces weissii CCUG 61299T (95.6-96.6 %), Actinomyces bovis CCTCC AB2010168T (95.7 %) and Actinomyces bowdenii DSM 15435T (95.2-96.4 %), with values of digital DNA-DNA hybridization less than 30.1 % when compared with their closest relatives but higher than 70 % within each pair of novel strains (ZJ34T/ZJ561, ZJ750T/ZJ1629 and zg-993T/zg-987). All the novel strains had C18 : 1 ω9c and C16 : 0 as the two most abundant major fatty acids. MK-9(H4) or MK-8(H4) was the sole or predominant respiratory quinone of strains ZJ34T, ZJ750T and zg-993T and their polar lipid profiles differed, but all had diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and phosphatidyl inositol mannoside as major components. ZJ750T shared identical peptidoglycan amino acid profile with ZJ34T (alanine, glutamic acid, lysine and ornithine) and the same whole-cell sugar composition with zg-993T (glucose, rhamnose and ribose). Strain zg-993T contained alanine, aspartic acid, glutamic acid, glycine and lysine in the peptidoglycan, and the only sugar in ZJ34T was ribose. The DNA G+C contents of the novel strains were within the range of 65.8-70.1 mol%. On the basis of the results from the aforementioned analyses, the six novel strains were classified as representing three novel species of genus Actinomyces, for which the names Actinomyces faecalis sp. nov. [type strain ZJ34T (=GDMCC 1.1952T=JCM 34355T)], Actinomyces respiraculi sp. nov. [type strain ZJ750T (=GDMCC 1.1950T=JCM 34356T)] and Actinomyces trachealis sp. nov. [type strain zg-993T (=GDMCC 1.1956T=JCM 34357T)] were proposed, respectively.

Molecular identification and antibiotic resistance pattern of actinomycetes isolates among immunocompromised patients in Iran, emerging of new infections.

Recent advancements in DNA-based approaches have led to the identification of uncommon and rare bacterial pathogens. In this study, by utilizing a DNA-based approach, a total of 1043 clinical specimens were processed for the identification of actinobacteria targeting the 16S rRNA and gyrB genes. Drug susceptibility testing was also conducted using micro-broth dilution and PCR. Two isolates of Nocardia flavorosea and Rhodococcus erythropolis were reported for the first time in Iran. Also, Nocardiopsis dassonvillei, Streptomyces olivaceus, and Streptomyces griseus were reported for the first time in Asia. Infections caused by Nocardia caishijiensis and Prauserella muralis have also been reported in this study. The first Asian case of pulmonary infection caused by Nocardia ignorata and the first global case of brain abscess caused by Nocardia ninae and Nocardia neocaledoniensis have been reported in this study. Overall 30 isolates belonging to 6 genera (Nocardia, Streptomyces, Rodoccoccus, Nocardiopsis, Rothia, and Prauserella) were detected in 30 patients. All 30 isolates were susceptible to amikacin and linezolid. Three isolates including Nocardia otitidiscaviarum (n = 2) and Nocardia flavorosea (n = 1) were resistant to trimethoprim-sulfamethoxazole which were the first trimethoprim-sulfamethoxazole resistant clinical actinomycetes in Iran. Isolation of rare species of actinomycetes particularly Nocardia spp. requires urgent action before they spread clinically particularly among immunocompromised patients.

Kibdelosporangium persicum sp. nov., a new member of the Actinomycetes from a hot desert in Iran.

Isolate 4NS15T was isolated from a neglected arid habitat in Kerman, Iran. The strain showed 16S rRNA gene sequence similarity values of 98.9 % to the type strains of Kibdelosporangium aridum subsp. aridum, Kibdelosporangium phytohabitans and Kibdelosporangium philippinense and 98.6 % to the type strain K. aridum subsp. largum, respectively. Genome-based phylogenetic analysis revealed that isolate 4NS15T is closely related to Kibdelosporangium aridum subsp. aridum DSM 43828T. The digital DNA-DNA hybridization value between the genome sequences of 4NS15T and strain DSM 43828T is 29.8 %. Strain 4NS15T produces long chains of spores without a sporangium-like structure which can be distinguished from other Kibdelosporangium species. Isolate 4NS15T has a genome size of 10.35 Mbp with a G+C content of 68.1 mol%. Whole-cell hydrolysates of isolate 4NS15T are rich in meso-diaminopimelic acid and cell-wall sugars such as arabinose, galactose, glucose and ribose. Major fatty acids (>10 %) are C16 : 0, iso-C16 : 0 and iso-C15 : 0. The phospholipid profile contains diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylhydroxyethanolamine, aminolipid and glycoaminolipid. The predominant menaquinone is MK-9(H4). Based on its phenotypic and genotypic characteristics, isolate 4NS15T (NCCB 100701=CIP 111705=DSM 110728) merits recognition as representing a novel species of the genus Kibdelosporangium, for which the name Kibdelosporangium persicum sp. nov. is proposed.

Pulmonary actinomycosis diagnosed by radial endobronchial ultrasound coupled with metagenomic next-generation sequencing: A case report and brief literature review.

Pulmonary actinomycosis (PA) is an uncommon pulmonary infectious disease that often is misdiagnosed. Metagenomic next-generation sequencing (mNGS) is a highly sensitive and culture-independent new molecular technology for precise infectious disease diagnosis. Here we report a PA case diagnosed by the combination of a radial endobronchial-ultrasonography guide sheath (R-EBUS-GS) and mNGS, along with a brief review of the literature.

Actinomyces wuliandei sp. nov., Corynebacterium liangguodongii sp. nov., Corynebacterium yudongzhengii sp. nov. and Oceanobacillus zhaokaii sp. nov., isolated from faeces of Tibetan antelope in the Qinghai-Tibet plateau of China.

Eight Gram-stain-positive, rod-shaped bacterial strains were isolated from faeces of Tibetan antelopes on the Tibet-Qinghai Plateau of China. Genomic sequence analysis showed that the strains belong to the genera Actinomyces (strains 299T and 340), Corynebacterium (strains 2184T, 2185, 2183T and 2189) and Oceanobacillus (strains 160T and 143), respectively, with a percentage of similarity for the 16S rRNA gene under the species threshold of 98.7 % except for strains 160T and 143 with Oceanobacillus arenosus CAU 1183T (98.8 %). The genome sizes (and genomic G+C contents) were 3.1 Mb (49.4 %), 2.5 Mb (64.9 %), 2.4 Mb (66.1 %) and 4.1 Mb (37.1 %) for the type strains 299T, 2183T, 2184T and 160T, respectively. Two sets of the overall genome relatedness index values between our isolates and their corresponding closely related species were under species thresholds (95 % for average nucleotide identity, and 70 % for digital DNA-DNA hybridization). These results, together with deeper genotypic, genomic, phenotypic and biochemical analyses, indicate that these eight isolates should be classified as representing four novel species. Strain 299T (=CGMCC 1.16320T=JCM 33611T) is proposed as representing Actinomyces wuliandei sp. nov.; strain 2184T (=CGMCC 1.16417T=DSM 106203T) is proposed as representing Corynebacterium liangguodongii sp. nov.; strain 2183T (=CGMCC 1.16416T=DSM 106264T) is proposed as representing Corynebacterium yudongzhengii sp. nov.; and strain 160T (=CGMCC 1.16367T=DSM 106186T) is proposed as representing Oceanobacillus zhaokaii sp. nov.

Actinomyces qiguomingii sp. nov., isolated from the Pantholops hodgsonii.

Two previously undescribed, Gram-stain-positive, rod-shaped strains, 410T and 553, were isolated from faeces of the Tibetan antelope (Pantholops hodgsonii) from the Tibet-Qinghai Plateau, PR China. The optimum growth conditions of the two novel strains were 1 % (w/v) NaCl, 37 °C and pH 7. The end products from glucose fermentation included ethanol and lactic acid. Based on results of 16S rRNA gene sequence comparison and phylogenetic and phylogenomic analyses, strains 410T and 553 were classified into the genus Actinomyces, and were closely related to Actinomyces ruminicola (97.6 %), Actinomyces oricola (93.5 %) and Actinomyces dentalis (90.8 %). The genomic G+C content of strain 410T was 67.4 mol%. Digital DNA-DNA hybridization values between strain 410T and each of the closely related species were under 70 %. The respiratory quinones were MK-10 (68 %) and MK-9 (32 %). The main cellular fatty acids of the isolates were C16 : 0, followed by C18 : 1 ω9c. The major polar lipids were diphosphatidylglycerol and phosphatidylinositol-mannoside. The whole-cell sugars contained rhamnose, ribose and glucose. The diagnostic amino acids of cell-wall peptidoglycan included alanine, glutamic acid, lysine and ornithine. The results of biochemical, chemotaxonomic and genotypic analyses revealed that the two novel strains represent a novel species of genus Actinomyces, for which the name Actinomyces qiguomingii sp. nov. is proposed. The type strain is 410T (=CGMCC 1.16361T= DSM 106201T).

Actinomyces lilanjuaniae sp. nov., isolated from the faeces of Tibetan antelope (Pantholops hodgsonii) on the Qinghai-Tibet Plateau.

Two novel, Gram-stain-positive, non-motile, facultatively anaerobic, rod-shaped bacteria (strains 2129T and 2119) were isolated from the faeces of Tibetan antelopes (Pantholops hodgsonii) on the Qinghai-Tibet Plateau, PR China. The 16S rRNA gene sequences of the strains showed highest similarity values to Actinomyces timonensis DSM 23838T (92.9 and 92.8 %, respectively), and phylogenetic analysis based on 16S rRNA gene and genomic sequences indicated that strains 2129T and 2119 represent a new lineage. Strains 2129T and 2119 could ferment d-adonitol and d-xylose, but were unable to utilize d-mannose and d-melibiose nor produce esterase (C4) and proline arylamidase. The G+C contents of the two strains were both 69.0 mol%. Their genomes exhibited less than 40.4 % relatedness in DNA-DNA hybridization tests (below 70 % as the recommended threshold for new species) with all available genomes of the genus Actinomyces in the NCBI database. The major fatty acids of the two strains were C18 : 1ω9c and C16 : 0, and the major polar lipids were diphosphatidylglycerol, glycolipid, phosphatidylinositol, phosphatidyl inositol mannoside and phosphoglycolipid. Based on the results of genotypic, phenotypic and biochemical analyses, it is proposed that the two unidentified bacteria be classified as representing a novel species, Actinomyces lilanjuaniae sp. nov. The type strain is 2129T (=CGMCC 4.7483T=DSM 106426T).

Modulation of Candida albicans virulence in in vitro biofilms by oral bacteria.

Candida-associated denture stomatitis presents as erythema of the palatal mucosa and is caused by biofilms containing the fungus Candida albicans that co-reside with oral bacteria on the denture-fitting surface. This study aimed to assess the effect of several frequently encountered oral bacteria on the expression of C. albicans virulence factors in in vitro polymicrobial biofilms. Biofilms containing C. albicans and selected bacterial species were grown on denture acrylic, and analysed by microscopy and by qPCR for expression of putative virulence genes. Candida albicans-only biofilms showed limited hyphal production. Hyphal development was significantly (P < 0·001) increased when biofilms also contained four species of oral bacteria (Streptococcus sanguinis, Streptococcus gordonii, Actinomyces odontolyticus and Actinomyces viscosus), as was the expression of virulence genes (P < 0·05). Importantly, inclusion of Porphyromonas gingivalis in the biofilm consortium resulted in significant (P < 0·05) inhibition of virulence gene expression and production of hyphae. The in vitro expression of C. albicans virulence factors was modulated in polymicrobial biofilms. The complexity of this modulation was highlighted by the reversal of effects following introduction of a single bacterial species into a biofilm community. SIGNIFICANCE AND IMPACT OF THE STUDY: The impact of individual bacterial species on Candida albicans virulence highlights both the complexity of predicting infection mediated by polymicrobial communities and the potential for management through pro- or prebiotic therapy. The possibility to selectively modulate microbial virulence by addition of, or treatment with pro- or prebiotics avoids the use of conventional antimicrobial compounds, thus reducing the contribution to potential drug resistance. Understanding which bacterial species modulate virulence, and the mechanisms by which this occurs, particularly in biofilms, provides excellent foundations for further research questions, and the potential for novel clinical interventions.

Actinomyces turicensis Necrotizing Soft-Tissue Infection of the Thigh in a Diabetic Male.

Background: Necrotizing soft-tissue infections are a devastating infection that is rarely caused by Actinomyces spp. Case Report: A 45-year-old obese previously healthy male presented to the emergency department with diabetic ketoacidosis. The patient developed systemic signs of infections and right medial thigh pain subsequently diagnosed as a necrotizing soft-tissue infection. Successful treatment included prompt surgical intervention and initiation of broad-spectrum antimicrobial drugs. Conclusion: Actinomyces turicensis may be the pathogen causing certain necrotizing soft-tissue infections. Clinicians should consider the possibility that this organism represents a true pathogen and not colonization/contamination.

A comparative assessment of the antibacterial activity of root canal sealers on 2 Actinomyces species: An in vitro study.

BACKGROUND: Actinomyces species have a low virulence and pathogenicity, but under specific circumstances they may be involved in root canal and periapical tissue infections. OBJECTIVES: The aim of the study was to investigate the antibacterial activity of various root canal sealers on standardized strains of Actinomyces. MATERIAL AND METHODS: The materials tested in this study included AH Plus™ Jet (AH), Apexit® Plus (AP), Endomethasone N (EN), GuttaFlow® (GF), Hybrid Root SEAL (HB), MTA Fillapex (FL), Real® Seal (RCS), Roeko Seal Automix (RSA), Sealapex™ (SP), and Tubli-Seal™ (TS). The antibacterial effect of the freshly mixed sealers on standardized strains of Actinomyces israelii NCTC 8047 and Actinomyces viscosus ATCC 15987 was evaluated with the use of the agar diffusion test (ADT). The results were obtained by measuring the diameter of the growth inhibition zone at 96 h and 1, 2, 3, and 4 weeks, and were analyzed in time using repeated measures analysis of variance (ANOVA). Statistically significant differences among the materials were determined by using one-way ANOVA and Tukey's post hoc testing. A paired Student's t-test was applied to compare the susceptibility of particular strains to each sealer. The critical level of significance for all tests was p < 0.05. RESULTS: Most sealers demonstrated growth inhibition zones against both tested bacteria, except for RSA and GF. Actinomyces viscosus was significantly more susceptible than A. israelii to AP, RCS (p < 0.001) and TS (p = 0.012). Actinomyces israelii was significantly more susceptible than A. viscosus to EN, HB and SP (p < 0.001). CONCLUSIONS: The antimicrobial effect of the examined materials varied considerably depending on the type of material and bacterial species tested. Most of the tested root canal sealers exhibited antibacterial activity on standardized strains of Actinomyces, with FL showing the highest antibacterial effect on both bacterial strains. Importantly, both standardized strains of Actinomyces were characterized by varied sensitivity to root canal sealers.

Case Report: Cervicovaginal Co-Colonization with Entamoeba gingivalis and Entamoeba polecki in Association with an Intrauterine Device.

Amoebic trophozoites were identified in the cervicovaginal smear of a U.S. patient without travel history at the time of intrauterine device (IUD) removal. Subsequent morphologic analysis and DNA sequencing identified a mixed cervicovaginal colonization of the female genital tract with both Entamoeba gingivalis and Entamoeba polecki in association with Actinomyces species bacteria. This highlights to the potential for colonization of the genital tract with E. gingivalis, particularly in association with IUD placement, and represents the first report of E. polecki in this context.

Actinomyces tangfeifanii sp. nov., isolated from the vulture Aegypius monachus.

A novel, Gram-stain-positive, catalase-positive, non-spore-forming, short rod-shaped strain (VUL4_3T) was isolated from rectal swabs of Old World vultures (Aegypius monachus) from the Tibet-Qinghai Plateau, China. Based on the results of biochemical tests and 16S rRNA gene sequence comparison, strain VUL4_3T was determined to be a member of the genus Actinomyces that is closely related to the type strains of Actinomyces liubingyangii (97.7 % 16S rRNA gene sequence similarity) and Actinomyces marimammalium (96.5 %). Optimal growth occurred at 37 °C, pH 6-7 and with 1 % (w/v) NaCl. The typical major cellular fatty acids of strain VUL4_3T were C18 : 1ω9c, C16 : 0 and C18 : 0. The VUL4_3T genome contained 2 207 832 bp with an average G+C content of 51.9 mol%. DNA-DNA hybridization values between strain VUL4_3T and the above two species of the genus Actinomyces showed less than 32 % DNA-DNA relatedness, supporting a novel species status of strain VUL4_3T. Based on the phenotypic data and phylogenetic inference, the novel species Actinomycestangfeifanii sp. nov. is proposed. The type strain is VUL4_3T (=CGMCC 4.7369T=DSM 103436T).

Actinomyces denticolens as a causative agent of actinomycosis in animals.

The name "Actinomyces suis" was applied to each actinomycete isolate from swine actinomycosis by Grässer in 1962 and Franke in 1973. Nevertheless, this specific species was not included in the "Approved List of Bacterial Name" due to absence of the type cultures. Therefore, "Actinomyces suis" based on the description of Franke 1973 has been considered as "species incertae sedis". We isolated a number of Actinomyces strains from swine. The representative strains of them was designated as Chiba 101 that was closely similar to the description in "Actinomyces suis" reported by Franke in 1973. Interestingly, it was found that the biological characteristics of these strains were also very similar to those of Actinomyces denticolens. Furthermore, the average nucleotide identity (ANI) value between strain Chiba 101 and the type-strain of Actinomyces denticolens (=DSM 20671T) was found to be 99.95%. Sequences of the housekeeping genes and 16S rRNA gene showed 100% homology. These results strongly suggested that "Actinomyces suis" Franke 1973 is the same species as Actinomyces denticolens. Since actinomycosis caused by Actinomyces denticolens have been demonstrated in horses recently, it is necessary to recognize that Actinomyces denticolens is the pathogenic actinomycetes in broader range of animals.

Identification and diversity of Actinomyces species in a clinical microbiology laboratory in the MALDI-TOF MS era.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a reliable tool for bacterial identification. This study compared the Bruker MALDI-TOF BioTyper MS (MBT) and 16S rRNA gene sequencing for the identification of Actinomyces and Actinotignum spp. The MBT identified 68/77 (88.3%) of Actinomyces isolates to the genus-level and 44/77 (57.1%) of Actinomyces isolates to the species-level using the manufacturer's identification criteria. The MBT did not yield reliable identification for only 1/77 (1.3%) and generated no identification for 8/77 (10.4%) of the isolates. No misidentifications were found. Discordance at the species level was observed for eight isolates. Overall, the MBT demonstrated good concordance with the 16S rRNA gene sequencing with the exception of the closely related species A. naeslundii, A. viscosus and A. oris. A variety of Actinomyces spp. were isolated from orocervicofacial/dental specimens, but only a limited number of species were isolated from urine or intra-abdominal specimens. This study confirms the utility of MBT in the identification of Actinomyces spp. and describes the diversity and anatomic niche of species in human clinical specimens from various body sites.

Characterization of a xylanolytic bacterial strain C10 isolated from the rumen of a red deer (Cervus elaphus) closely related of the recently described species Actinomyces succiniciruminis, A. glycerinitolerans, and A. ruminicola.

Gram-stain-positive, catalase and oxidase-negative and short rod-shaped bacterium C10 with occasional branching was isolated under strictly anaerobic conditions from the rumen fluid of a red deer (Cervus elaphus) in the course of study attempting to uncover new xylanolytic and cellulolytic rumen bacteria inhabiting the digestive tract of wild ruminants in the Czech Republic. The anaerobic M10 medium containing bovine rumen fluid and carboxymethylcellulose as a defined source of organic carbon was used in the process of bacterial isolation. The 16S rRNA gene similarity revealed recently characterized new species Actinomyces succiniciruminis Am4T (GenBank accession number of the gene retrieved from the complete genome: LK995506) and Actinomyces glycerinitolerans G10T (GenBank accession number from the complete genome: NZFQTT01000017) as the closest relatives (99.7 and 99.6% gene pairwise identity, respectively), followed by the Actinomyces ruminicola DSM 27982T (97.2%, in all compared fragment of 41468 pb). Due to the taxonomic affinity of the examined strain to both species A. succiniciruminis and A. glycerinitolerans, its taxonomic status towards these species was evaluated using variable regions of rpsA (length of 519 bp) and rplB (597 bp) gene sequences amplified based on specific primers designed so as to be applicable in differentiation, classification, and phylogeny of Actinomyces species/strains. Comparative analyses using rpsA and rplB showed 98.5 and 97.9% similarities of C10 to A. succiniciruminis, respectively, and 97.5 and 97.6% similarities to A. glycerinitolerans, respectively. Thus, gene identities revealed that the evaluated isolate C10 (=DSM 100236 = LMG 28777) is a little more related to the species A. succiniciruminis isolated from the rumen of a Holstein-Friesian cow than A. glycerinitolerans. Phylogenetic analyses confirmed affinity of strain C10 to both recently characterized species. Unfortunately, they did not allow the bacterial strain to be classified into a particular species. Phenotypic characterization suggested similar conclusions. This brief contribution is aimed at classification and detailed phenotypic characterization of bacterial strain C10 isolated from the rumen of a wild red deer exhibiting, from the point of view of Actinomyces species, noteworthy cellulolytic and xylanolytic activities.

Actinomyces gaoshouyii sp. nov., isolated from plateau pika (Ochotona curzoniae).

Two strains (pika_113T and pika_114) of a previously undescribed Actinomyces-like bacterium were recovered from the intestinal contents of plateau pika (Ochotona curzoniae) on the Tibet-Qinghai Plateau, China. Results from biochemical characterization indicated that the two strains were phenotypically homogeneous and distinct from other previously described species of the genus Actinomyces. Based on the comparison of 16S rRNA gene sequences and genome analysis, the bacteria were determined to be a hitherto unknown subline within the genus Actinomyces, being most closely related to type strains of Actinomyces denticolens and Actinomyces timonensis with a respective 97.2 and 97.1 % similarity in their 16S rRNA gene sequences. Phylogenetic analyses confirmed that pika_113T was well separated from any other recognized species of the genus Actinomyces and within the cluster with A. denticolens and A. timonensis. The genome of strain pika_113T displayed less than 42 % relatedness in DNA-DNA hybridization with all the available genomes of existing species of the genus Actinomyces in the NCBI database. Collectively, based on the phenotypic characteristics and phylogenetic analyses results, we propose the novel isolates as representatives of Actinomyces gaoshouyii sp. nov. The type strain of Actinomyces gaoshouyii is pika_113T (=CGMCC 4.7372T=DSM 104049T), with a genomic DNA G+C content of 71 mol%.

Detection of Actinomyces spp. in cervical exudates from women with cervical intraepithelial neoplasia or cervical cancer.

PURPOSE: Under certain circumstances, Actinomyces behaves as an opportunistic microorganism and can cause actinomycosis, a chronic and inflammatory granulomatous infection. The purpose of this project was to detect the presence of Actinomyces in cervical exudates from women with cervical intraepithelial neoplasia (CIN) and women with cervical cancer. METHODOLOGY: Cervical samples from 92 women were divided into three groups: CIN, cervical cancer and healthy women. Metagenomic DNA extraction was performed following the Qiagen QIAamp Mini Kit protocol. A specific fragment (675 bp) was amplified by PCR in order to detect the presence of Actinomycetales. Samples in which Actinomycetales was detected were subjected to separate amplification reactions with primer pairs for A. israelii, A. viscosus, A. meyeri and A. odontolyticus. Amplified products were observed by 2 % agarose gel electrophoresis. RESULTS: Actinomyces were found in 10 % of women with CIN, 36.6 % of women with cervical cancer and 9 % of healthy women. The species identified in this study were A. meyeri in 14/92 samples (15.2 %), A. viscosus in 10/92 samples (10.8 %), A. odontolyticus in 4/92 samples (4.3 %) and A. israelii in 6/92 samples (6.5 %). CONCLUSION: Patients with cervical cancer had a higher prevalence of the presence of Actinomyces compared to the CIN and control groups. This is the first study in which a deliberate search of this genus has been performed in women with cervical pathologies. The use of specific primers for each species facilitated their detection in comparison with traditional isolation methods. More information is necessary to understand the molecular mechanisms involved in the complex role that bacterial communities may play in the development of cancer (and vice versa).

Actinomyces radicidentis and Actinomyces haliotis, coccoid Actinomyces species isolated from the human oral cavity.

There are few reports on the bacterial species Actinomyces radicidentis in the literature. In this study, putative A. radicidentis isolates were collected from 16 root canal samples from 601 examined patients. The isolates were examined by biochemical tests, 16S rRNA gene sequencing, Arbitrarily-primed (AP-) PCR, antibiotic susceptibility testing, and MALDI-TOF analyses. In parallel, two A. radicidentis reference strains and two putative A. radicidentis isolates from United Kingdom were tested. Sixteen of the 18 isolates were confirmed as A. radicidentis. The remaining two isolates, both of which were isolated from root canals (one from Sweden and the other from the UK), but were identified as Actinomyces haliotis by sequencing âˆ¼ 1300 base pairs of the 16S rRNA-gene. This isolates had a divergent, but between them similar, AP-PCR pattern, and a common distribution of sequence signatures in the 16S rRNA gene, but were not identified by MALDI-TOF. A. haliotis is a close relative to A. radicidentis, hitherto only been described from a sea-snail. The identity of A. haliotis was confirmed by a phylogenetic tree based on 16S rRNA gene sequences with species specific sequences included, and by additional biochemical tests. The examined bacteria exhibited similar antibiotic susceptibility patterns when tested for 10 separate antibiotic classes with E-tests (bioMérieux). The MIC90 for ß-lactams (benzylpenicillin and cefuroxime) and vancomycin was 0.5 mg/L, for colistin and ciprofloxacin 8 mg/mL and for the other antibiotic classes ≤ 25 mg/mL The isolation of A. haliotis from infected dental root canals cast doubt on the accepted opinion that all Actinomyces infections have an endogenous source.