Cariogenic actinomyces identified with a beta-glucosidase-dependent green color reaction to Gardenia jasminoides extract

The Comprehensive Profiling of the Chemical Components in the Raw and Processed Roots of Scrophularia ningpoensis by Combining UPLC-Q-TOF-MS Coupled with MS/MS-Based Molecular Networking

Scrophulariae Radix (SR), the dried root of Scrophularia ningpoensis Hemsl (S. ningpoensis), has been extensively used as traditional Chinese medicine for thousands of years. However, since the mid-20th century, the traditional processing technology of S. ningpoensis has been interrupted. Therefore, ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry technology, together with a Global Natural Product Social Molecular Networking (GNPS) method, was applied to comprehensively analyze the characteristic changes and mutual transformation of chemical constituents in the differently processed roots of S. ningpoensis, as well as to scientifically elucidate the processing mechanism of differently processed SR. As a result, a total of 149 components were identified. Notably, with the help of the GNPS data platform and MS2 fragment ions, the possible structures of four new compounds (47, 48, 50, and 73) were deduced in differently processed SR samples, in which 47, 48, and 50 are iridoid glycosides, and 73 is a phenylpropanoid glycoside. Five cyclopeptides (78, 86, 97, 99, and 104) derived from leucine (isoleucine) were identified in SR for the first time. The heatmaps analysis results indicated that leucine or isoleucine may be converted to cyclopeptides under the prolonged high-temperature conditions. Moreover, it is found that short-time steaming can effectively prevent the degradation of glycosides by inactivating enzymes. This study provides a new and efficient technical strategy for systematically identifying the chemical components, rapidly discovering the components, and preliminarily clarifying the processing mechanism of S. ningpoensis, as well as also providing a scientific basis for the improvement of the quality standards and field processing of S. ningpoensis.

Optimization of Extraction of Four Components from Radix Scrophulariae with Natural Deep Eutectic Solvents and Evaluation of Extract's Antioxidant Activity

In this research, eight natural deep eutectic solvents (NaDESs) consisting of food-grade ingredients were screened for the extraction of four bioactive compounds (acteoside, cinnamic acid, angoroside C and harpagoside) from radix scrophulariae (RS). Among these NaDESs, Proline-Glycerol NaDES with higher comprehensive score was selected. The Criteria Importance Through Intercriteria Correlation (CRITIC) was applied to calculate the information entropy and the weight of indexes, and figured out a comprehensive score. The weights of acteoside, cinnamic acid, angoroside C and harpagoside were 0.369, 0.172, 0.241 and 0.218, respectively. Response surface methodology (RSM) mathematical model was used to optimize the extraction parameters. The optimal extraction parameters were as follows: extraction time with 42.21 min, NaDES concentration with 52.89%, solid-to-liquid ratio with 1 : 37.05 g/mL and the predicted value of comprehensive score was 0.885. Under the optimal condition, the comprehensive score was 0.903 ± 0.005. Finally, the antioxidant activity experiment revealed that the 1,1-Diphenyl-2-picrylhydrazyl · radical scavenging activity and hydroxyl radical scavenging activity of the extract at 2.0 mg/mL and 1.5 mg/mL were approximately equal to those of ascorbic acid, respectively. The results showed that the extraction condition optimized by RSM combined with CRITIC was reasonable and dependable, and the extract of radix scrophulariae exhibited good antioxidant activity.

The role of Actinomyces spp. and related organisms in cervicofacial infections: Pathomechanism, diagnosis and therapeutic aspects

Members of the Actinomyces genus and Actinomyces-like organisms (ALOs; namely Actinotignum, Arcanobacterium, Schaalia and Varibaculum) are Gram-positive, non-spore-forming rods that are commensal members of the human oral cavity, gastrointestinal tract, female genital tract and skin microbiota. Cervicofacial actinomycosis or "lumpy jaw syndrome" - the chronic, suppurative granulomatous disease caused by Actinomyces spp. And ALOs - is characterized by an initially slow and unspecific disease-presentation, which often mimics other pathologies, followed by the formation of painful abscesses and severe tissue destruction. Actinomycosis has been described as a rare disease, however, reliable epidemiological data are lacking. In addition, there is increasing awareness regarding the role of Actinomyces spp. in the development of osteoradionecrosis and medication-related osteonecrosis of the jaw. The aim of this narrative review is to succinctly summarize the current advances regarding the microbiological, clinical, diagnostic and therapeutic aspects of cervicofacial actinomycosis, in addition to the roles of Actinomyces species and ALOs as members of the oral microbiota and in dental biofilm, in other dental infections (caries, root canal infection, periapical infection, periodontitis) and osteonecrosis of the jaw, in the context of recent taxonomic changes affecting the genus. Our paper aims to be a blueprint for dentists, other physicians, microbiologists and researchers regarding the multifaceted field of cervicofacial actinomycosis.

One-Pot Preparation of Cetylpyridinium Chloride-Containing Nanoparticles for Biofilm Eradication

Quaternary ammonium compounds (QACs) have been widely used due to their excellent antimicrobial activity. However, using the technology where nanomaterials are employed as drug carriers to deliver QAC drugs has not been fully explored. In this study, mesoporous silica nanoparticles (MSNs) with short rod morphology were synthesized in a one-pot reaction using an antiseptic drug cetylpyridinium chloride (CPC). CPC-MSN were characterized via various methods and tested against three bacterial species (Streptococcus mutans, Actinomyces naeslundii, and Enterococcus faecalis), which are associated with oral infections, caries, and endodontic pathology. The nanoparticle delivery system used in this study prolonged the release of CPC. The manufactured CPC-MSN effectively killed the tested bacteria within the biofilm, and their size allowed them to penetrate into dentinal tubules. This CPC-MSN nanoparticle delivery system demonstrates potential for applications in dental materials.

Meta-analysis of caries microbiome studies can improve upon disease prediction outcomes

As one of the most prevalent infective diseases worldwide, it is crucial that we not only know the constituents of the oral microbiome in dental caries but also understand its functionality. Herein, we present a reproducible meta-analysis to effectively report the key components and the associated functional signature of the oral microbiome in dental caries. Publicly available sequencing data were downloaded from online repositories and subjected to a standardized analysis pipeline before analysis. Meta-analyses identified significant differences in alpha and beta diversities of carious microbiomes when compared to healthy ones. Additionally, machine learning and receiver operator characteristic analysis showed an ability to discriminate between healthy and disease microbiomes. We identified from importance values, as derived from random forest analyses, a group of genera, notably containing Selenomonas, Aggregatibacter, Actinomyces and Treponema, which can be predictive of dental caries. Finally, we propose the most appropriate study design for investigating the microbiome of dental caries by synthesizing the studies, which had the most accurate differentiation based on random forest modelling. In conclusion, we have developed a non-biased, reproducible pipeline, which can be applied to microbiome meta-analyses of multiple diseases, but importantly we have derived from our meta-analysis a key group of organisms that can be used to identify individuals at risk of developing dental caries based on oral microbiome inhabitants.

Nitric oxide-releasing hyperbranched polyaminoglycosides for antibacterial therapy

Hyperbranched polyaminoglycosides were prepared by the polymerization of kanamycin, gentamicin, and neomycin, and N,N'-methylenebis(acrylamide) via a one-pot reaction. The secondary amines at the linear units of the hyperbranched polymers were subsequently reacted with NO gas at high pressure under alkaline conditions to form N-diazeniumdiolate NO donors. The resulting NO-releasing hyperbranched polyaminoglycosides exhibited a wide range of NO payloads (~0.4-1.3 µmol mg-1) and release kinetics (half-lives ~70-180 min). The therapeutic utility of these materials was evaluated by examining their bactericidal activity against common dental pathogens and toxicity to human gingival fibroblast cells. The antibacterial efficacy of NO-releasing hyperbranched polyaminoglycosides was dependent on specific physiochemical properties, with greater degrees of branching and aminoglycoside terminal groups correlating to enhanced action. Nitric oxide-releasing hyperbranched polykanamycin and polyneomycin elicited the least cytotoxicity at bactericidal concentrations, indicating the greatest therapeutic index for future biomedical applications.

Genetics and Cell Morphology Analyses of the Actinomyces oris srtA Mutant

Sortase is a cysteine-transpeptidase that anchors LPXTG-containing proteins on the Gram-positive bacterial cell wall. Previously, sortase was considered to be an important factor for bacterial pathogenesis and fitness, but not cell growth. However, the Actinomyces oris sortase is essential for cell viability, due to its coupling to a glycosylation pathway. In this chapter, we describe the methods to generate conditional srtA deletion mutants and identify srtA suppressors by Tn5 transposon mutagenesis. We also provide procedures for analyzing cell morphology of this mutant by thin-section electron microscopy. These techniques can be applied for analyses of other essential genes in A. oris.

A correlative study of the levels of salivary Streptococcus mutans, lactobacilli and Actinomyces with dental caries experience in subjects with mixed and permanent dentition

Purpose:

The aim of the study was to estimate the salivary levels of Streptococcus mutans, Lactobacilli and Actinomyces and to correlate it with dental caries experience in mixed and permanent dentition.

Materials and Methods:

The sample size comprised 110 subjects. The decayed, missing and filled teeth (DMFT) index of all the individuals participating in the study was calculated. Saliva samples were collected from patients and samples were inoculated on specific culture media and incubated for a period of 48 h. Based on colony characteristics, S. mutans, Lactobacilli and Actinomyces were identified.

Results:

A positive correlation exists between DMFT and S. mutans, Lactobacilli and Actinomyces in mixed dentition and permanent dentition group samples (P < 0.001).

Conclusion:

The conclusion from the results obtained was that S. Mutans, lactobacilli and Actinomyces which are the components of the normal microbial flora of the oral cavity play an important role in the pathogenesis of dental caries and increased number of microorganisms is associated with an increased caries frequency.