Cell-free nucleic acids (cf-NAs) represent a promising biomarker of various pathological and physiological conditions. Since its discovery in 1948, cf-NAs gained prognostic value in oncology, immunology, and other relevant fields. In peritoneal dialysis (PD), blood purification is performed by exposing the peritoneal membrane. Relevant sections: Complications of PD such as acute peritonitis and peritoneal membrane aging are often critical in PD patient management. In this review, we focused on bacterial DNA, cell-free DNA, mitochondrial DNA (mtDNA), microRNA (miRNA), and their potential uses as biomarkers for monitoring PD and its complications. For instance, the isolation of bacterial DNA in early acute peritonitis allows bacterial identification and subsequent therapy implementation. Cell-free DNA in peritoneal dialysis effluent (PDE) represents a marker of stress of the peritoneal membrane in both acute and chronic PD complications. Moreover, miRNA are promising hallmarks of peritoneal membrane remodeling and aging, even before its manifestation. In this scenario, with multiple cytokines involved, mtDNA could be considered equally meaningful to determine tissue inflammation.
This review explores the relevance of cf-NAs in PD, demonstrating its promising role for both diagnosis and treatment. Further studies are necessary to implement the use of cf-NAs in PD clinical practice.

The practice of naming elements from the natural world after notable individuals stretches back to ancient times. This practice of creating eponyms-terms derived from personal names-has been carried forward into prokaryotic nomenclature, where the International Code of Nomenclature of Prokaryotes (ICNP) sets guidelines for creating scientific names from personal names. However, these guidelines can be seen as culturally biased, disjointed and, on occasion, misguided. Here, with the goal of modernizing these recommendations to render them more user-friendly, coherent and inclusive, I review current practice in the light of precedents and key linguistic and cultural principles, while questioning the applicability of the first-name/last-name paradigm for many cultural traditions. Procedural challenges include romanization of the personal name (including handling of diacritics), creation of a short and agreeable latinized stem, assignment of the stem to a declension and addition of suffixes or compound word components to create genus names or species epithets, customizing the approach for names and stems that end in a vowel. I review the pros and cons of stem augmentation, which involves addition of an extra \'i\' to the original stem. Next, I formulate a coherent workflow, which I incorporate into a Python script to enable computer-based automation of name creation. Rather than following the ICNP in limiting discussion to a few dozen mainly European names, I examine how these principles work out when applied to the tens of thousands of last names under which scientists publish in the PubMed database, focusing on edge cases where conventional approaches fail, particularly very short and very long names. Drawing on these explorations and analyses, I propose emendations to the advice currently presented in the ICNP to usher in a modern, consistent, pragmatic and globally inclusive approach to the creation of prokaryotic eponyms.

The existence of a placental microbiota is debated. The human placenta has historically been considered sterile and microbial colonization was associated with adverse pregnancy outcomes. Yet, recent DNA sequencing investigations reported a microbiota in typical human term placentas. However, this detected microbiota could represent background DNA or delivery-associated contamination. Using fifteen publicly available 16S rRNA gene datasets, existing data were uniformly re-analyzed with DADA2 to maximize comparability. While Amplicon Sequence Variants (ASVs) identified as Lactobacillus, a typical vaginal bacterium, were highly abundant and prevalent across studies, this prevalence disappeared after applying likely  DNA contaminant removal to placentas from term cesarean deliveries. A six-study sub-analysis targeting the 16S rRNA gene V4 hypervariable region demonstrated that bacterial profiles of placental samples and technical controls share principal bacterial ASVs and that placental samples clustered primarily by study origin and mode of delivery. Contemporary DNA-based evidence does not support the existence of a placental microbiota.ImportanceEarly-gestational microbial influences on human development are unclear. By applying DNA sequencing technologies to placental tissue, bacterial DNA signals were observed, leading some to conclude that a live bacterial placental microbiome exists in typical term pregnancy. However, the low-biomass nature of the proposed microbiome and high sensitivity of current DNA sequencing technologies indicate that the signal may alternatively derive from environmental or delivery-associated bacterial DNA contamination. Here we address these alternatives with a re-analysis of 16S rRNA gene sequencing data from 15 publicly available placental datasets. After identical DADA2 pipeline processing of the raw data, subanalyses were performed to control for mode of delivery and environmental DNA contamination. Both environment and mode of delivery profoundly influenced the bacterial DNA signal from term-delivered placentas. Aside from these contamination-associated signals, consistency was lacking across studies. Thus, placentas delivered at term are unlikely to be the original source of observed bacterial DNA signals.

The intestinal microbiota plays a major role in infant health and development. However, the role of the breastmilk microbiota in infant gut colonisation remains unclear. A systematic review was performed to evaluate the composition of the breastmilk microbiota and evidence for transfer to/colonisation of the infant gut. Searches were performed using PUBMED, OVID, LILACS and PROQUEST from inception until 18th March 2020 with a PUBMED update to December 2021. 88 full texts were evaluated before final critique based on study power, sample contamination avoidance, storage, purification process, DNA extraction/analysis, and consideration of maternal health and other potential confounders. Risk of skin contamination was reduced mainly by breast cleaning and rejecting the first milk drops. Sample storage, DNA extraction and bioinformatics varied. Several studies stored samples under conditions that may selectively impact bacterial DNA preservation, others used preculture reducing reliability. Only 15 studies, with acceptable sample size, handling, extraction, and bacterial analysis, considered transfer of bacteria to the infant. Three reported bacterial transfer from infant to breastmilk. Despite consistent evidence for the breastmilk microbiota, and recent studies using improved methods to investigate factors affecting its composition, few studies adequately considered transfer to the infant gut providing very little evidence for effective impact on gut colonisation.

DNA recombination repair systems are essential for organisms to maintain genomic stability. In recent years, we have improved our understanding of the mechanisms of RecBCD/AddAB family-mediated DNA double-strand break repair. In E. coli, it is RecBCD that plays a central role, and in Firmicute Bacillus subtilis it is the AddAB complex that functions. However, there are open questions about the mechanism of DNA repair in bacteria. For example, how bacteria containing crossover hotspot instigator (Chi) sites regulate the activity of proteins. In addition, we still do not know the exact process by which the RecB nuclease or AddA nuclease structural domains load RecA onto DNA. We also know little about the mechanism of DNA repair in the industrially important production bacterium Corynebacterium glutamicum (C. glutamicum). Therefore, exploring DNA repair mechanisms in bacteria may not only deepen our understanding of the DNA repair process in this species but also guide us in the targeted treatment of diseases associated with recombination defects, such as cancer. In this paper, we firstly review the classical proteins RecBCD and AddAB involved in DNA recombination repair, secondly focus on the novel helical nuclease AdnAB found in the genus Mycobacterium.

Members of the anaerobic gut fungi (Neocallimastigomycota) reside in the rumen and alimentary tract of larger mammalian and some reptilian, marsupial and avian herbivores. The recent decade has witnessed a significant expansion in the number of described Neocallimastigomycota genera and species. However, the difficulties associated with the isolation and maintenance of Neocallimastigomycota strains has greatly complicated comparative studies to resolve inter- and intra-genus relationships. Here, we provide an updated outline of Neocallimastigomycota taxonomy. We critically evaluate various morphological, microscopic and phylogenetic traits previously and currently utilized in Neocallimastigomycota taxonomy, and provide an updated key for quick characterization of all genera. We then synthesize data from taxa description manuscripts, prior comparative efforts and molecular sequence data to present an updated list of Neocallimastigomycota genera and species, with an emphasis on resolving relationships and identifying synonymy between recent and historic strains. We supplement data from published manuscripts with information and illustrations from strains in the authors\' collections. Twenty genera and 36 species are recognized, but the status of 10 species in the genera Caecomyces, Piromyces, Anaeromyces and Cyllamyces remains uncertain due to the unavailability of culture and conferre (cf.) strains, lack of sequence data, and/or inadequacy of available microscopic and phenotypic data. Six cases of synonymy are identified in the genera Neocallimastix and Caecomyces, and two names in the genus Piromyces are rejected based on apparent misclassification.

Paenibacilli are gram-variable, endospore-forming bacteria that occupy various ecologic niches. These microorganisms have been known to infect humans occasionally at various anatomic sites. However, in humans, as well as in other vertebrate animals, the relationship between disease and isolation of Paenibacillus spp. remains poorly understood. We report here a case of infection in an adult Poodle dog. The animal had nodules in the lungs and multifocal osteolytic expansile bone lesions. From bone, Paenibacillus amylolyticus was recovered by culture and identified by MALDI-TOF mass spectroscopy and 16S rDNA sequencing; pyogranulomatous inflammation was observed in lung and bone specimens. The microorganism was resistant to clindamycin and imipenem. Four-month treatment with amoxicillin-clavulanate resulted in clinical resolution of disease in this dog. Nevertheless, therapy for more prolonged periods should be considered because recurrent infections can occur as a result of the transition of Paenibacillus spores to vegetative cells. Disease caused by a Paenibacillus species has not been reported previously in dogs, to our knowledge.

DNA barcodes are regarded as hereditary succession codes that serve as a recognition marker to address several queries relating to the identification, classification, community ecology, and evolution of certain functional traits in organisms. The mitochondrial cytochrome c oxidase 1 (CO1) gene as a DNA barcode is highly efficient for discriminating vertebrate and invertebrate animal species. Similarly, different specific markers are used for other organisms, including ribulose bisphosphate carboxylase (rbcL), maturase kinase (matK), transfer RNA-H and photosystem II D1-ApbsArabidopsis thaliana (trnH-psbA), and internal transcribed spacer (ITS) for plant species; 16S ribosomal RNA (16S rRNA), elongation factor Tu gene (Tuf gene), and chaperonin for bacterial strains; and nuclear ITS for fungal strains. Nevertheless, the taxon coverage of reference sequences is far from complete for genus or species-level identification. Applying the next-generation sequencing approach to the parallel acquisition of DNA barcode sequences could greatly expand the potential for library preparation or accurate identification in biodiversity research. Overall, this review articulates on the DNA barcoding technology as applied to different organisms, its universality, applicability, and innovative approach to handling DNA-based species identification.

Approximately 1.41 million people die annually due to tuberculosis. One of the main problems in Tuberculosis eradication is the development of resistance to various antibiotics. However, current efforts to detect resistances face challenges such as limited equipment, budget, and time. This evidence-based review investigated loop-mediated isothermal amplification, an alternative molecular diagnostic tool with promising performance and applicability in developing countries, and its use combined with Au-Nanoprobe to detect antibiotic resistance in tuberculosis. The literature search was conducted through four databases (Proquest, EBSCOhost, Scopus, and Pubmed) for useful articles on loop-mediated isothermal amplification and Au-Nanoprobe in detecting tuberculosis and tuberculosis resistance. After filtering the result with inclusion and exclusion criteria, the search produced three papers that best answer the clinical question. Loop-mediated isothermal amplification amplifies a target sequence, and Au-Nanoprobe responds to the DNA specific to the target mutant, producing an observable color change. Loop-mediated isothermal amplification and Au-Nanoprobe showed 100% sensitivity and specificity in detecting rifampicin and isoniazid resistance. Another study investigated its viability to detect tuberculosis and found 98.2% sensitivity and 88.2% specificity. Combining loop-mediated isothermal amplification and Au-Nanoprobe had a shorter time to get results and should also be relatively cheaper because it does not need a high temperature to work and requires less equipment. In conclusion, loop-mediated isothermal amplification and Au-Nanoprobe can be used as an efficient and accurate method to detect isoniazid and rifampicin-resistant tuberculosis strains. The new technology is promising for developing countries due to their high disease burden but facing several healthcare barriers.

Nontuberculous mycobacteria (NTM) infection is similar to Mycobacterium tuberculosis (MTB) infection. Early clinical identification and differentiation of NTM and MTB infections continues to be a major challenge. Nucleic acid amplification tests (NAATs) have the ability to efficiently and rapidly detect pathogens and are widely used in mycobacterial infections. The objective of this study is to estimate the diagnostic accuracy of NAATs for NTM.
We will search candidate studies that assessing the accuracy of NAATs for diagnosis of NTM through PubMed, Embase and the Cochrane Library until May 2021. Studies with full text that meet the inclusion criteria will be included. Following a revised tool for Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2), two researchers will independently evaluate the study quality. The STATA software (version 15.0) will be used to carry out meta-analyses. When heterogeneity is observed, subgroup analyses and meta-regression analyses will be used to explore sources of heterogeneity. Sensitivity analyses will be used to check the robustness of analyses.
We hope that this study will provide meaningful evidence for the early and rapid diagnosis of NAATs for NTM, which will help to guide the treatment of NTM and improve the prognosis of patients.