Choclo virus (CHOV) recovered from deep metatranscriptomics of archived frozen tissues in natural history biorepositories.

BACKGROUND: Hantaviruses are negative-stranded RNA viruses that can sometimes cause severe disease in humans; however, they are maintained in mammalian host populations without causing harm. In Panama, sigmodontine rodents serve as hosts to transmissible hantaviruses. Due to natural and anthropogenic forces, these rodent populations are having increased contact with humans. METHODS: We extracted RNA and performed Illumina deep metatranscriptomic sequencing on Orthohantavirus seropositive museum tissues from rodents. We acquired sequence reads mapping to Choclo virus (CHOV, Orthohantavirus chocloense) from heart and kidney tissue of a two-decade old frozen museum sample from a Costa Rican pygmy rice rat (Oligoryzomys costaricensis) collected in Panama. Reads mapped to the CHOV reference were assembled and then validated by visualization of the mapped reads against the assembly. RESULTS: We recovered a 91% complete consensus sequence from a reference-guided assembly to CHOV with an average of 16X coverage. The S and M segments used in our phylogenetic analyses were nearly complete (98% and 99%, respectively). There were 1,199 ambiguous base calls of which 93% were present in the L segment. Our assembled genome varied 1.1% from the CHOV reference sequence resulting in eight nonsynonymous mutations. Further analysis of all publicly available partial S segment sequences support a clear relationship between CHOV clinical cases and O. costaricensis acquired strains. CONCLUSIONS: Viruses occurring at extremely low abundances can be recovered from deep metatranscriptomics of archival tissues housed in research natural history museum biorepositories. Our efforts resulted in the second CHOV genome publicly available. This genomic data is important for future surveillance and diagnostic tools as well as understanding the evolution and pathogenicity of CHOV.

Great diversity of KSα sequences from bat-associated microbiota suggests novel sources of uncharacterized natural products.

Polyketide synthases (PKSs) are multidomain enzymes in microorganisms that synthesize complex, bioactive molecules. PKS II systems are iterative, containing only a single representative of each domain: ketosynthase alpha (KS[Formula: see text]), ketosynthase beta and the acyl carrier protein. Any gene encoding for one of these domains is representative of an entire PKS II biosynthetic gene cluster (BGC). Bat skin surfaces represent an extreme environment prolific in Actinobacteria that may constitute a source for bioactive molecule discovery. KS[Formula: see text] sequences were obtained from culturable bacteria from bats in the southwestern United States. From 467 bat bacterial isolates, we detected 215 (46%) had KS[Formula: see text] sequences. Sequencing yielded 210 operational taxonomic units, and phylogenetic placement found 45 (21%) shared <85% homology to characterized metabolites. Additionally, 16 Actinobacteria genomes from the bat microbiome were analyzed for biosynthetic capacity. A range of 69-93% of the BGCs were novel suggesting the bat microbiome may contain valuable uncharacterized natural products. Documenting and characterizing these are important in understanding the susceptibility of bats to emerging infectious diseases, such as white-nose syndrome. Also noteworthy was the relationship between KS [Formula: see text] homology and total BGC novelty within each fully sequenced strain. We propose amplification and detection of KS[Formula: see text] could predict a strain's global biosynthetic capacity.

Breathing can be dangerous: Opportunistic fungal pathogens and the diverse community of the small mammal lung mycobiome.

Human lung mycobiome studies typically sample bronchoalveolar lavage or sputum, potentially overlooking fungi embedded in tissues. Employing ultra-frozen lung tissues from biorepositories, we obtained fungal ribosomal RNA ITS2 sequences from 199 small mammals across 39 species. We documented diverse fungi, including common environmental fungi such as Penicillium and Aspergillus, associates of the human mycobiome such as Malassezia and Candida, and others specifically adapted for lungs (Coccidioides, Blastomyces, and Pneumocystis). Pneumocystis sequences were detected in 83% of the samples and generally exhibited phylogenetic congruence with hosts. Among sequences from diverse opportunistic pathogens in the Onygenales, species of Coccidioides occurred in 12% of samples and species of Blastomyces in 85% of samples. Coccidioides sequences occurred in 14 mammalian species. The presence of neither Coccidioides nor Aspergillus fumigatus correlated with substantial shifts in the overall mycobiome, although there was some indication that fungal communities might be influenced by high levels of A. fumigatus. Although members of the Onygenales were common in lung samples (92%), they are not common in environmental surveys. Our results indicate that Pneumocystis and certain Onygenales are common commensal members of the lung mycobiome. These results provide new insights into the biology of lung-inhabiting fungi and flag small mammals as potential reservoirs for emerging fungal pathogens.

A Review of Coccidioides Research, Outstanding Questions in the Field, and Contributions by Women Scientists.

PURPOSE OF REVIEW: Coccidioidomycosis is an infectious disease that gained clinical significance in the early 20th century. Many of the foundational contributions to coccidioidomycosis research, including the discovery of the fungal disease agent, Coccidioides spp., were made by women. We review recent progress in Coccidioides research and big questions remaining in the field, while highlighting some of the contributions from women. RECENT FINDINGS: New molecular-based techniques provide a promising method for detecting Coccidioides, which can help determine the dominate reservoir host and ideal environmental conditions for growth. Genetic and genomic analyses have allowed an understanding of population structure, species level diversity, and evolutionary histories. We present a current, comprehensive genome list, where women contributed many of these entries. Several efforts to develop a coccidioidomycosis vaccine are underway. SUMMARY: Women continue to pioneer research on Coccidioides, including the relationships between the fungi and the environment, genetics, and clinical observations. Significant questions remain in the field of Coccidioides, including the main host reservoir, the relationships between genotypic and phenotypic variation, and the underlying cause for chronic clinical coccidioidomycosis cases.

Proximal caries infiltration - Pragmatic RCT with 4 years of follow-up.

OBJECTIVES: Efficacy of proximal caries infiltration to arrest lesion progression has been shown in university settings, but only once in a practice-based pragmatic design with a follow-up of 18 months. The aim of this randomized split-mouth placebo-controlled study was to follow-up this cohort for 3 years and those with high caries risk for 4 years. METHODS: Originally, in 87 children and young adults pairs of 238 proximal caries lesions, radiographically extending into inner half of enamel (E2) or outer third of dentin (D1), were randomly allocated to two groups: infiltration (Icon; DMG) or mock (control) treatment by five dentists in four private practices. All subjects received risk-related instructions for diet, flossing and fluoridation. The primary outcome was radiographic lesion progression (pairwise comparison) evaluated by two evaluators independently being blinded to treatment allocation. RESULTS: After 36 months [mean (SD): 1152 (166) days] 165 lesion pairs in 64 patients as well as after 48 months [mean (SD): 1496 (121) days] 71 lesion pairs in 20 high caries risk patients could be re-evaluated clinically as well as radiographically using individualized bitewing holders as at baseline. No adverse events could be observed. After 36 months, progression was recorded in 23/165 test (14%) and 64/165 control lesions (39%) [McNemar/Obuchowski test; p<0.001; relative risk reduction (CI95%): 64 (45-77%)]. After 48 months lesion progression was recorded in 13/71 test (18%) and 34/71 control lesions (48%) [p = 0.003; relative risk reduction (CI95%): 62 (34-78%)] of high caries risk patients. CONCLUSIONS: It can be concluded that also in a practice-setting proximal caries infiltration is more efficacious in reducing lesion progression compared with individualized non-invasive measures alone over a period of four years.

Differential Thermotolerance Adaptation between Species of Coccidioides.

Coccidioidomycosis, or Valley fever, is caused by two species of dimorphic fungi. Based on molecular phylogenetic evidence, the genus Coccidioides contains two reciprocally monophyletic species: C. immitis and C. posadasii. However, phenotypic variation between species has not been deeply investigated. We therefore explored differences in growth rate under various conditions. A collection of 39 C. posadasii and 46 C. immitis isolates, representing the full geographical range of the two species, was screened for mycelial growth rate at 37 °C and 28 °C on solid media. The radial growth rate was measured for 16 days on yeast extract agar. A linear mixed effect model was used to compare the growth rate of C. posadasii and C. immitis at 37 °C and 28 °C, respectively. C. posadasii grew significantly faster at 37 °C, when compared to C. immitis; whereas both species had similar growth rates at 28 °C. These results indicate thermotolerance differs between these two species. As the ecological niche has not been well-described for Coccidioides spp., and disease variability between species has not been shown, the evolutionary pressure underlying the adaptation is unclear. However, this research reveals the first significant phenotypic difference between the two species that directly applies to ecological research.

Streptomyces buecherae sp. nov., an actinomycete isolated from multiple bat species.

A putative novel clade within the genus Streptomyces was discovered following antifungal screening against Pseudogymnoascus destructans, the causative agent of white-nose syndrome, and described using multi-locus sequencing analysis. Swabs from both the cave myotis bat (Myotis velifer) and the Brazilian free-tailed bat (Tadarida brasiliensis) in southern New Mexico bore isolates AC536, AC541T and AC563, which were characterised using phylogenetic, morphological, and phenotypic analyses. Multi-locus sequence analysis positions AC541T with neighbors Streptomyces rubidus (NRRL B-24619T), Streptomyces guanduensis (NRRL B-24617T), and Streptomyces yeochonensis (NRRL B-24245T). A complete genome of the type strain was assembled to determine its taxonomy and secondary metabolite potential. ANI comparisons between all closely related types strains are shown to be well below the 95-96% species delineation. DNA-DNA relatedness between AC541T and its nearest neighbors ranged between 23.7 and 24.1% confirming novelty. Approximately 1.49 Mb or 17.76% of the whole genome is devoted to natural product biosynthesis. The DNA G + C content of the genomic DNA of the type strain is 73.13 mol %. Micromorphology depicts ovoid spores with smooth surfaces in flexuous chains. Strains presented an ivory to yellow hue on most ISP media except inorganic salts-starch agar (ISP4) and can grow on D-glucose, mannitol, and D-fructose, but exhibited little to no growth on L-arabinose, sucrose, D-xylose, inositol, L-rhamnose, D-raffinose, and cellulose. This clade possesses the capability to grow from 10 to 45 °C and 12.5% (w/v) NaCl. There was strain growth variation in pH, but all isolates thrive at alkaline levels. Based on our polyphasic study of AC541T, the strain warrants the assignment to a novel species, for which the name Streptomyces buecherae sp. nov. is proposed. The type strain is AC541T (= JCM 34263T, = ATCC TSD201T).

Keratinophilic fungi: Specialized fungal communities in a desert ecosystem identified using cultured-based and Illumina sequencing approaches.

Soil fungi in desert ecosystems are adapted to harsh environmental conditions such as high soil surface temperatures and limited organic matter and water. Given limited carbon inputs from plant material, heterotrophic fungi likely use unconventional sources of carbon in these systems. A baiting method was used to culture keratinophilic fungi from biocrust and rhizosphere soils in an arid grassland in Utah, USA. Fungi were baited using llama and sheep wool, horsehair, and snakeskin on two media, and pure cultures were identified using ITS and LSU rRNA sequences. One hundred-eighteen fungal colonies were grown, representing a total of 32 Operational Taxonomic Units (OTUs) at 97 % similarity. Cultures were dominated by the phylum Ascomycota (88 %) followed by Mucoromycota (8.6 %) and Basidiomycota (3.4 %). The orders Pleosporales, Eurotiales, Hypocreales, and Sordariales were commonly isolated, with the dominant taxa Alternaria (27 %), Aspergillus (22 %), Fusarium (11 %), and Chaetomium (8%). Thirty percent of the fungi isolated have the capacity to degrade keratin in vitro using a keratin azure assay, with Penicillium showing the highest degradation followed by Geomyces, Alternaria, and Fusarium. Although keratin degraders can be infectious, dermatophytes associated with skin infections were not isolated in culture or detected in Illumina sequencing. Illumina sequencing was used to determine general patterns in seasonal variation and habitat preference of keratinophiles. Alternaria was the most abundant genus with >70 % of the sequences. The combination of Illumina data with culture-dependent approaches facilitated the characterization of a specialized community and confirmed the low abundance of dermatophytes in this arid site.

Seven-year-efficacy of proximal caries infiltration - Randomized clinical trial.

OBJECTIVES: We report efficacy of resin infiltration to arrest progression of caries lesions as compared with non-invasive measures and oral hygiene education alone after a mean observation time of seven years. MATERIALS AND METHODS: This randomized split-mouth placebo-controlled clinical trial included 22 young adults having 29 pairs of interproximal non-cavitated caries lesions with radiographic extensions into inner half of enamel (E2) or outer third of dentin (D1). Lesion pairs were randomly allocated to two treatment groups: infiltration (Icon, pre-product; DMG) or mock (control) treatment. All subjects received risk-related instructions for diet, flossing and fluoridation. The primary outcome was radiographic (digital subtraction radiography) lesion progression after seven years. Secondly, Kaplan-Meier-analyses were applied to analyze time-to-failure additionally including patients followed up for less than 54 months as well. RESULTS: Two lesion pairs were excluded due to invasive treatment decision by another dentist, five lesion pairs were lost to follow-up prior to 54 months but included in the survival analysis. No unwanted effects could be observed. For the primary outcome in 17 patients followed up in mean for 84 months 2/22 infiltrated lesions (9 %) compared with 10/22 control lesions (45 %) progressed (p = 0.018). The relative risk reduction for test in relation to control was 80 % (CI 95 % = 19-95 %). For the survival analysis within a mean (SD) observation time of 73 (25) months mean failure rates of 1.3 % and 7.8 % could be observed for test and controls, respectively. Hazard risk (95 % CI) for caries progression was 6.6 (2-22) for the control compared with the test lesions (p = 0.002). CONCLUSIONS: We conclude that resin infiltration of proximal caries lesions extending radiographically around the enamel dentin junction is efficacious to reduce lesion progression after a mean observation time of seven years. CLINICAL SIGNIFICANCE: This randomized clinical trial proves that caries infiltration is highly efficacious compared with non-invasive measures and oral hygiene education alone after a considerably longer observation time of 7 years than studied so far before.

First Analysis of Human Coccidioides Isolates from New Mexico and the Southwest Four Corners Region: Implications for the Distributions of C. posadasii and C. immitis and Human Groups at Risk.

Coccidioidomycosis (Valley Fever) is a disease caused by species of Coccidioides. The disease is endemic to arid regions of the Southwestern US and while most common in CA and AZ is also present in NM. We present the first genetic analysis of clinical isolates from NM. Travel and demographic information was available for a number of patients, which included individuals from NM and the Southwestern US Four Corners region. Multi-gene phylogenetic analyses revealed the presence of both C. posadasii and C. immitis. While NM is predicted to be within the endemic range for C. posadasii, our results expand the known range of C. immitis, often considered to be the "California species". Five of eight infections for which patient ethnicity existed occurred in Native Americans, and two occurred in African Americans. Several isolates came from the northwestern part of NM-outside the predicted "highly-endemic" region. Our study suggests Native Americans represent an unrecognized at-risk group, and it provides a foundation for better defining the geographic distribution of the Coccidioides species and for preventing exposure among populations at risk. In the course of this study, we developed a reliable PCR-based method to distinguish species targeting regions of the mitochondrial genome.

Streptomyces corynorhini sp. nov., isolated from Townsend's big-eared bats (Corynorhinus townsendii).

Four bacterial strains, with the capability of inhibiting Pseudogymnoascus destructans, the causative agent of white-nose syndrome, were isolated from male Townsend's big-eared bats (Corynorhinus townsendii, Family: Vespertilionidae) in New Mexico. Isolates AC161, AC162, AC208, and AC230T were characterised as a novel clade using morphological, phenotypic and phylogenetic analysis. A draft genome of the type strain was completed to determine its taxonomy and secondary metabolite biosynthetic potential. Multi-locus sequence analysis nests AC230T with neighbours Streptomyces scopuliridis (NRRL B-24574T), Streptomyces lushanensis (NRRL B-24994T), Streptomyces odonnellii (NRRL B-24891T) and Streptomyces niveus (NRRL 2466T). Further phylogenetic analysis showed the MLSA distances between AC230T and its near neighbours are much greater than the generally accepted threshold (> 0.007) for bacterial species delineation. DNA-DNA relatedness between AC230T and its near neighbours ranged between 25.7 ± 2.1 and 29.9 ± 2.4%. The DNA G+C content of the genomic DNA of the type strain is 71.7 mol%. Isolate AC230T presents a white to ivory hue on most ISP media and its micromorphology exhibits ovoid spores with smooth surfaces in flexuous chains. Based on our study of AC230T, the strain warrants the assignment to a novel species, for which the name Streptomyces corynorhini sp. nov. is proposed. The type strain is AC230T (= JCM 33171T, = ATCC TSD155T).

Accuracy of tactile assessment in order to detect proximal cavitation of caries lesions in vitro.

OBJECTIVES: Discriminating non-cavitated from cavitated proximal lesions without tooth separation is only limitedly possible using visual-radiographic assessment alone. We evaluated how additional tactile assessment might increase the accuracy of this discrimination in vitro. METHODS: Surface integrity of 46 primary molars with proximal lesions extending radiographically into outer third of dentin (ICDAS-codes: 2 n = 34, 3 n = 8 and 5 n = 4) were mounted in groups of two in manikin heads and independently assessed by three examiners using visual-radiographic and additional tactile assessment using a cow-horn-ended explorer with or without gingival displacement. After examination, lesion surfaces were evaluated for possible damage using scanning-electronic microscopy. Analysis of variance (ANOVA) was performed for evaluating if tactile assessment and gingival displacement significantly affected accuracy. RESULTS: Tactile assessment significantly increased sensitivity of detecting cavities (p < 0.001, ANOVA), but decreased specificity (p < 0.05). Sensitivities/specificities varied between 33 (8)%/96 (1)% and 86 (6)%/84 (5)%. Gingival displacement had no significant impact on accuracy (p > 0.05). Scanning-electron microscopy revealed no cavitation. CONCLUSIONS: In vitro, tactile assessment of proximal surfaces was useful and safe. CLINICAL RELEVANCE: Analysis of the cavitation level by using a cow-horn-ended probe might be leading to useful information in addition to bitewing assessment under clinical circumstances.

Modified resin infiltration of non-, micro- and cavitated proximal caries lesions in vitro.

OBJECTIVE: Infiltrant resin (IR) is currently indicated for non-cavitated caries lesions. However, modifying the technique might expand its indication spectrum to micro-cavitated lesions. The present study aimed to evaluate the penetration/filling ability of a newly developed micro-filled infiltrant resin (MFIR) in non-, micro- and cavitated natural caries lesions. MATERIALS AND METHODS: Proximal lesions in 120 extracted human teeth with ICDAS-2 (n = 30), 3 (n = 45) and 5 (n = 45) lesions were etched with 15% hydrochloric acid gel for 2 min and allocated to one of the following treatments; IR: lesions (ICDAS-2, 3 and 5; each n = 15) were treated with commercial infiltrant resin for 3 min. MFIR: experimental MFIR [55 wt% IR plus 45 wt% organic fillers] was applied to lesions (ICDAS-2, 3 and 5; each n = 15) for 3 min. IR + FC: IR was applied for 3 min, light-cured, and cavities (ICDAS-3 and 5; each n = 15) filled with flowable composite (FC). Percentage infiltration of the demineralized enamel (Inf.%) and percentage filling of the cavity (Fill.%) were analyzed using dual-fluorescence staining and confocal microscopy. RESULTS: No significant differences in Inf.% (range of medians: 57%-100%) were observed between different treatments (p > 0.05; Kruskal-Wallis) within each ICDAS-code. Fill.% of cavities was significantly higher in groups MFIR (median in ICDAS-3/-5: 100%/100%) and IR + FC (100%/100%) than IR (25%/38%) (p < 0.05). CONCLUSION: MFIR showed similar penetration into natural lesions as the commercial infiltrant, but better ability to fill cavitated areas. CLINICAL RELEVANCE: MFIR and IR + FC might provide a new micro-invasive treatment for small cavitated proximal lesions.

Micro-filled resin infiltration of fissure caries lesions in vitro.

OBJECTIVES: The aim of this in vitro study was to evaluate three treatment modalities [infiltrant resin (IR), micro-filled infiltrant resin (MFIR), infiltrant-sealant-combination (ISC)] regarding both their abilities to penetrate lesions differing in ICDAS-codes and to fill fissures and cavities. MATERIALS AND METHODS: Extracted human molars (n=90) showing fissure caries lesions with and without cavitations were etched with 15% hydrochloric acid (HCl) that was mixed with abrasives and a 15% HCl-solution (1:1). The etching gel was rubbed for 30s within the fissure and, if eligible, within the cavity using a brush. After this pretreatment an infiltrant (Icon; DMG; IR) or an infiltrant mixed with microfillers (MFIR) was applied. ISC included the application of an infiltrant followed by a fissure sealant (Helioseal; Ivoclar Vivadent) From each tooth slices showing a non-cavitated (based on ICDAS-2) or cavitated lesion part (based on ICDAS-3/5) were prepared. Lesion (LA) and penetration areas (PA) as well as the completeness of fissure and cavity filling were analyzed using dual staining and confocal laser scanning microscopy. RESULTS: Percentage penetration (PP) was calculated as 100×PA/LA. PP [median (25th/75th)] did not differ significantly between IR [95 (86/100)%], MFIR [93 (62/100)%] or ISC [89 (67/97)%] (p>0.05; Kruskal-Wallis test). All three materials filled about 90% of the dimensions of fissures and cavities (p>0.05; Kruskal-Wallis test). CONCLUSION: It can be concluded that MFIR seems to be suitable to fill fissures and cavities like a fissure sealant and that it penetrates fissure caries lesions similarly deep as the conventional infiltrant after an experimental etching regime. CLINICAL SIGNIFICANCE: The MFIR seems to combine advantages of the fissure sealing and the caries infiltration procedure.

Effects of dentifrices differing in fluoride compounds on artificial enamel caries lesions in vitro.

The aim of this study was to compare the caries-preventive effect of a stabilized stannous fluoride/sodium fluoride dentifrice containing sodium hexametaphosphate with those of a regular, solely sodium fluoride-containing and amine fluoride-containing dentifrice on pre-demineralized bovine enamel specimens using a pH-cycling model. Bovine enamel specimens with two artificial lesions each were prepared. Baseline mineral loss of both lesions was analyzed using transversal microradiography (TMR). Eighty-five specimens with a mean (SD) baseline mineral loss of 3393 (683) vol% × µm were selected and randomly allocated to five groups (n = 13/15). Treatments during pH-cycling (28 days and 2 × 20 min demineralization/day) were: brushing twice daily with slurries of AmF (1400 ppm F-), NaF (1450 ppm F-), SnF2/NaF (1100 ppm F-/350 ppm F-), and fluoride-free (FF) dentifrices or they were immersed in distilled water and remained unbrushed (NB). Subsequently, from each specimen one lesion was covered with acid-resistant varnish, while the remaining lesion was demineralized for another 14 days. Differences in integrated mineral loss (∆∆Z) were calculated between values before and after pH-cycling (∆∆Z E1) as well as before pH-cycling and after second demineralization (∆∆Z E2) using TMR. Treatments AmF and NaF induced a significantly higher mineral gain (∆∆Z E1/∆∆Z E2) compared to treatments FF and NB (p < 0.05; ANOVA test). Except for treatments AmF and NaF no significant differences in mineral loss between before and after pH-cycling could be observed (p < 0.05; t test) [∆∆Z E1: AmF:1563 (767); NaF:1222 (1246); SnF2/NaF:258 (1259); FF:-52 (1223); NB:-151 (834)]. Both dentifrices with either AmF or NaF promoted remineralization, whereas SnF2/NaF dentifrice did not promote remineralization in a biofilm-free pH-cycling model.

Western Bats as a Reservoir of Novel Streptomyces Species with Antifungal Activity.

At least two-thirds of commercial antibiotics today are derived from Actinobacteria, more specifically from the genus Streptomyces Antibiotic resistance and new emerging diseases pose great challenges in the field of microbiology. Cave systems, in which actinobacteria are ubiquitous and abundant, represent new opportunities for the discovery of novel bacterial species and the study of their interactions with emergent pathogens. White-nose syndrome is an invasive bat disease caused by the fungus Pseudogymnoascus destructans, which has killed more than six million bats in the last 7 years. In this study, we isolated naturally occurring actinobacteria from white-nose syndrome (WNS)-free bats from five cave systems and surface locations in the vicinity in New Mexico and Arizona, USA. We sequenced the 16S rRNA region and tested 632 isolates from 12 different bat species using a bilayer plate method to evaluate antifungal activity. Thirty-six actinobacteria inhibited or stopped the growth of P. destructans, with 32 (88.9%) actinobacteria belonging to the genus Streptomyces Isolates in the genera Rhodococcus, Streptosporangium, Luteipulveratus, and Nocardiopsis also showed inhibition. Twenty-five of the isolates with antifungal activity against P. destructans represent 15 novel Streptomyces spp. based on multilocus sequence analysis. Our results suggest that bats in western North America caves possess novel bacterial microbiota with the potential to inhibit P. destructansIMPORTANCE This study reports the largest collection of actinobacteria from bats with activity against Pseudogymnoascus destructans, the fungal causative agent of white-nose syndrome. Using multigene analysis, we discovered 15 potential novel species. This research demonstrates that bats and caves may serve as a rich reservoir for novel Streptomyces species with antimicrobial bioactive compounds.

Margin Integrity and Secondary Caries of Lined or Non-lined Composite and Glass Hybrid Restorations After Selective Excavation In Vitro.

OBJECTIVES: For deep carious lesions, selective carious tissue removal (leaving soft dentin close to the pulp) is suggested. Afterward, different restoration materials, such as resin composites or glass hybrids (GHs), can be placed. Many dentists also apply setting or non-setting calcium hydroxide liners before restoration. We compared margin integrity and susceptibility for secondary caries in differently restored premolars in vitro. METHODS: In 48 extracted human premolars, artificial residual lesions were induced on pulpo-axial walls of standardized cavities. Teeth were restored using a GH (Equia Forte) or adhesively placed resin composite restoration (OptiBond FL and Tetric EvoCeram) without any liner (RC), resin composite restoration with a non-setting calcium hydroxide liner (RC_NCH), or resin composite restoration with a setting calcium hydroxide liner (RC_SCH). After thermomechanical cycling, groups (n=12) were compared regarding their gingivocervical margin integrity (proportion of irregularities, microgaps, gaps >5 µm, overhangs). Teeth were then submitted to a continuous culture Lactobacillus rhamnosus biofilm model. After 14 days, bacterial numbers in biofilms, along tooth-restoration margins and mineral loss (ΔZ) of secondary lesions, were determined. RESULTS: GH and RC_NCH showed significantly higher proportions of irregularities than RC and RC_SCH (p<0.05/Mann-Whitney). GH also showed significantly more gaps than alternative restorations (p<0.05). Bacterial numbers and ΔZ did not differ significantly between groups (p>0.05). CONCLUSIONS: GH and composites lined with non-setting calcium hydroxide showed reduced margin integrity compared with non-lined composites or composites lined with setting calcium hydroxide. This did not increase susceptibility for secondary caries.

Observations of mineralised tissues of teeth in X-ray micro-computed tomography.

BACKGROUND: The one of the most recent imaging technology is X-ray microtomography which allows non-invasive three-dimensional visualisation of structures. It also offers the opportunity to conduct a comprehensive quantitative analysis of the tested objects such as measuring the shares of the various phases, determining the material density and distribution of the size of pores and particles. The aim of the paper was to present an overview on the applicability and relevance of X-ray microtomography in the study of mineralised tissues of the teeth. MATERIALS AND METHODS: The article is based on the most recent and significant literature and own observations. RESULTS: The use of X-ray microtomography in dentistry has recently increased and includes, inter alia, the assessment of the density of minerals in enamel and dentin, the detection of demineralisation in an artificially and a naturally induced caries, the automatic measurement of the depth of cavities in dentin, the measurement of the amount of removed dentin in preparation of carious lesions by various methods, the assessment of microleakage around fillings and fissure sealants, cortical bone density measurement, evaluation of root canal morphology, comparison of the accuracy of root canal working and filling by various methods. CONCLUSIONS: X-ray microtomography offers within the analysis of mineralised tissues - complex structures of bone, teeth and biomedical materials, turn out to be indispensable since it opens new opportunities for cognitive and implementation research.

When and How to Intervene in the Caries Process.

The decrease in caries prevalence in many industrialized countries and the improved knowledge about the etiology and pathogenesis of caries have shifted the focus of caries therapy over the past decades toward less invasive approaches. Studies on caries progression indicate that it is generally quite slow in most patients today which should lead to a reconsideration of the practice of early invasive intervention. Today noninvasive (eg, fluorides) and microinvasive (occlusal sealing, proximal infiltration) therapeutic options that address etiological factors are gaining importance. The goal of these therapies is to heal or at least to slow down the progress of the disease. Noninvasive treatments are mainly related to controlling pathogenic factors (ie, sugar consumption) and enhancing protective factors (mainly oral hygiene and fluorides). Microinvasive treatments do not rely on the compliance of the patient as much, since these treatments include a resinous material that is applied to serve as a diffusion barrier for acids formed by cariogenic bacteria in the overlying plaque. To establish a minimum intervention treatment strategy for caries, the disease must be diagnosed at an early stage. In addition to assessing caries lesions in single teeth, individual risk factors need to be identified so that the underlying causes related to patients' behavioral patterns that led to the disease can be addressed as well. The patient should be informed about the scientific evidence related to the treatment choices in a participative atmosphere. Decision trees may help to make the range of findings comprehensible and the therapeutic shared decision-making process understandable to the patients.