Ribosomal DNA Sequences Research Articles

Microbiota in patients with cefuroxime resistance and anal fistula revealed by 16S ribosomal DNA.

Anal fistula is increasingly prevalent due to modern lifestyle factors, and surgery remains the primary treatment. However, the rising incidence of antibiotic resistance, particularly to cefuroxime, complicates perioperative management. The role of gut microbiota in influencing this resistance is not well understood. To investigate the relationship between gut microbiota composition and cefuroxime resistance in anal fistula patients and to assess probiotic intervention impact. This study included 30 anal fistula patients categorized into cefuroxime-sensitive (Cefur-S) and cefuroxime-resistant (Cefur-NS) groups. Gut microbiota samples were collected during colonoscopy, and 16S ribosomal DNA sequencing was performed to analyze microbial diversity. Patients in the Cefur-NS group received a 7-day course of Clostridium butyricum tablets. Post-intervention, microbial composition and cefuroxime resistance were reassessed. Alpha and beta diversity analyses showed no significant differences in microbial diversity between the Cefur-S and Cefur-NS groups. However, effect size analysis identified Roseburia and Butyricicoccus as dominant genera in the Cefur-S group, with higher butyrate production potentially protecting against cefuroxime resistance. Post-intervention, the Cefur-NS group showed a significant reduction in cefuroxime resistance, improved stool consistency, and reduced bowel movement frequency. This study suggests that specific gut microbiota, particularly Butyricicoccus and Roseburia, may mitigate cefuroxime resistance in anal fistula patients by increasing butyrate production. Probiotic intervention targeting gut microbiota composition presents a promising strategy for reducing antibiotic resistance and improving clinical outcomes.

Decoding the chicken gastrointestinal microbiome

Metataxonomic studies have underpinned a vast understanding of microbial communities residing within livestock gastrointestinal tracts, albeit studies have often not been combined to provide a global census. Consequently, in this study we characterised the overall and common ‘core’ chicken microbiota associated with the gastrointestinal tract (GIT), whilst assessing the effects of GIT site, bird breed, age and geographical location on the GIT resident microbes using metataxonomic data compiled from studies completed across the world. Specifically, bacterial 16S ribosomal DNA sequences from GIT samples associated with various breeds, differing in age, GIT sites (caecum, faeces, ileum and jejunum) and geographical location were obtained from the Sequence Read Archive and analysed using the MGnify pipeline. Metataxonomic profiles produced across the 602 datasets illustrated the presence of 3 phyla, 25 families and 30 genera, of which core genera (defined by presence in over 90% of datasets) belonged to Lactobacillus, Faecalibacterium, Butyricicoccus, Eisenbergiella, Subdoligranulum, Oscillibacter, Clostridium & Blautia. PERMANOVA analysis also showed that GIT site, bird breed, age and geographical location all had a significant effect on GIT microbial diversity, regardless of dietary factors, which were not considered in this study. On a genus level, Faecalibacterium was most abundant in the caeca, Lactobacillus was most abundant in the faeces, ileum and jejunum, with the data showing that the caeca and faeces were most diverse. AIL F8 progeny, Ross 308 and Cobb 500 breeds GIT bacteria were dominated by Lactobacillus, and Eisenbergiella, Megamonas and Bacteroides were most abundant amongst Sasso-T451A and Tibetan chicken breeds. Microbial communities within each GIT site develop with age, from a Lactobacillus and Streptococcus dominated community during the earlier stages of growth, towards a Faecalibacterium, Eisenbergiella, Bacteroides, Megamonas, and Lactobacillus dominated community during the later stages of life. Geographical locations, and thus environmental effectors, also impacted upon gastrointestinal tract microbiota, with Canadian and European datasets being dominated by Lactobacillus, whilst UK and Chinese datasets were dominated by Eisenbergiella and Bacteroides respectively. This study aids in defining what ‘normal’ is within poultry gastrointestinal tract microbiota globally, which is imperative to enhancing the microbiome for productive and environmental improvements.

Molecular Epidemiology and Antifungal Susceptibility Profile of Candidozyma Isolates From Argentina.

Epidemiological surveillance of Candidozyma sp. has become important because many species of this new genus have been reported to be responsible for nosocomial outbreaks and to exhibit elevated minimal inhibitory concentrations (MIC) to one or more classes of antifungal drugs. To describe the genetic relationships among Argentinian clinical isolates belonging to the Candidozyma genus and to study the molecular mechanisms associated with antifungal resistance. We performed whole-genome sequencing of 41 isolates. Identification was based on ribosomal DNA sequencing and susceptibility testing was determined according to the EUCAST document. Phylogenetic analysis, non-synonymous mutations in genes associated with antifungal resistance and the presence of copy number variations (CNVs) were investigated. We identified 12 Candidozyma haemuli, 11 Candidozyma haemuli var. vulneris, 5 Cz. haemuli/ Cz. haemuli var. vulneris ITS hybrids, 8 Candidozyma duobushaemuli and 5 Candidozyma cf. pseudohaemuli. Phylogenetic analysis, together with clinical data, demonstrated nosocomial transmission events. In addition, Cz. haemuli and Cz. haemuli var. vulneris were not separated in the phylogenetic tree; the Cz. cf. pseudohaemuli isolates clustered distantly from the Cz. pseudohaemuli type strain. Most isolates were resistant to amphotericin B, and two Cz. haemuli isolates showed fluconazole resistance and Y132F mutation in ERG11. We did not find CNV in genes associated with antifungal resistance. These findings highlight the need for epidemiological surveillance of these species and the study of molecular mechanisms associated with antifungal resistance. Furthermore, we propose a taxonomic revision for Cz. haemuli var. vulneris and Cz. pseudohaemuli based on genomic data.

Electroacupuncture Alleviates Neuropathic Pain and Negative Emotion in Mice by Regulating Gut Microbiota.

Neuropathic pain (NP) is a prevalent chronic condition frequently accompanied by adverse emotional states. Previous research has demonstrated the clinical efficacy of electroacupuncture (EA) in mitigating neuropathic pain and its associated mood disorders. Recent studies have underscored a correlation between gut microbiota and both NP and negative emotional states. Nevertheless, the relationship between the modulation of gut microbiota by EA and the amelioration of NP remains inadequately understood. Mice were randomly assigned to one of the three groups: the Control (Con) group, the EA group, and the Chronic Constrictive Injury (CCI) group (n = 12 each). Starting from the 8th day post-CCI induction, the EA group underwent EA treatment once every two days, for a total of 20 sessions. To investigate the impact of gut microbiota on CCI mice, we employed a variety of methods, including various behavioral tests and 16S ribosomal DNA (rDNA) sequencing. The results indicated that EA significantly ameliorated mechanical allodynia and emotional dysfunction induced by CCI in mice. Analysis through 16S rDNA sequencing revealed that the gut microbiota of NP model mice exhibited a marked increase in diversity. However, EA could partially reverse changes in the diversity of gut microbiota. The abundance of Alloprevotella, A2, Roseburia, Muribaculum, Ruminiclostridium, and Rikenella was increased, and the abundance levels of Bacteroides were decreased at the genus level in CCI mice. Following EA treatment, the relative abundance of Alistipes, A2, Roseburia, and Rikenella was decreased, whereas the relative abundance of Alloprevotella and Parabacteroides was increased in EA group when compared with the CCI group. These findings suggested that EA exerted a significant therapeutic effect on NP, potentially through modulation of the gut microbiota.

Two new myxozoan parasites, Myxobolus mayarum n. sp. and Kudoa mayarum n. sp., infecting the neotropical fish Mayan Cichlid, Mayaheros urophthalmus (Günther, 1862) in the Yucatán Peninsula, Mexico.

The biodiversity of freshwater fishes is extensive in Mexico; however, knowledge of their associated myxozoan parasites is limited. This study aimed to recognize myxozoan parasites in the endemic fish Mayaheros urophthalmus. Two new species, Myxobolusmayarum n. sp. and Kudoamayarum n. sp. were described from M. urophthalmus collected in the Celestún Coastal Lagoon and Baldiosera Freshwater Spring from the Yucatán Peninsula. Myxobolusmayarum n. sp. was found in 100% of the examined fish, infecting the gills, kidney, pectoral fins, and spleen. The spores were round, 11.34 ± 0.67 μm length, 10.03 ± 0.44 μm width, and 7.22 ± 0.45 μm thickness. The polar capsules were pyriform and equal in size, 3.85 ± 0.29 μm length and 2.27 ± 0.20 μm width. The polar tubule 30.71 ± 2.10 μm long and coiled 5-6 times. Kudoamayarum n. sp. was found in 30% of fish, infecting the heart, oesophagus, and stomach. The spores were subspherical, 5.40 ± 0.40 μm length and 5.76 ± 0.37 μm width. The polar capsules were ellipsoidal and equal in size, 1.90 ± 0.27 μm length and 1.46 ± 0.20 μm width. The phylogenetic analyses based on the small and large subunits ribosomal DNA (18S rDNA and 28S rDNA) sequences demonstrated that these two species are distinct from other published myxozoans, providing evidence to support the description of two new species. This study constitutes the first record of myxozoans from the Yucatán Peninsula, contributing to increase the knowledge about the biodiversity of myxozoans in neotropical regions.

First Case of Vulvovaginal Trichosporonosis Due to <i>Trichosporon coremiiforme</i> and Review of Recent Literature

Introduction: Trichosporon spp. are emerging basidiomycetous yeasts that can cause both superficial and invasive infections. Trichosporon coremiiforme is phylogenetically closely related to T. asahii. It has been isolated from various clinical samples; however, to date, there have been no reports of vulvovaginal infections caused by T. coremiiforme. This case report contributes to our understanding of T. coremiiforme infections and its potential to cause invasive infections in immunocompetent patients. Case Presentation: A 35-year-old woman with vulvovaginitis, a history of recurrent infections, and menorrhagia was referred to Babol Medical Center. The infection was confirmed through recultivation at two different sampling times, and the strain was identified as T. coremiiforme using ribosomal DNA sequencing. The patient was treated with voriconazole and miconazole. Conclusions: This is the first reported case of vulvovaginal trichosporonosis caused by T. coremiiforme in an immunocompetent patient. It underscores the importance of prompt and accurate identification of infections, even in immunocompetent individuals, for timely treatment.

Elucidation of intragenomic variation of ribosomal DNA sequences in the enigmatic fungal genus Ceraceosorus, including a newly described species Ceraceosorus americanus

AbstractMulticopy nuclear ribosomal DNA (rDNA) genes have been used as markers for fungal identification for three decades. The rDNA sequences in a genome are thought to be homogeneous due to concerted evolution. However, intragenomic variation of rDNA sequences has recently been observed in many fungi, which may make fungal identification and species abundance estimation based on these loci problematic. Ceraceosorus is an enigmatic genus in the smut lineage Ustilaginomycotina for which very limited distribution data exist. Our previous research demonstrated intragenomic variation in the internal transcribed spacer (ITS1-5.8S-ITS2) region of two Ceraceosorus species. In this study, we described the fourth known species of Ceraceosorus, C. americanus, isolated from an asymptomatic rosemary leaf collected in Louisiana, USA. This is the first report of this genus in the Americas. We then selected all four known Ceraceosorus species, plus exemplar smut fungi representing all major lineages of subphylum Ustilaginomycotina, to examine sequence heterogeneity in three regions of the rDNA repeat (partial 18S, ITS, and partial 28S regions). Three methods were used: PCR-cloning-Sanger sequencing, targeted amplicon high-throughput sequencing, and whole-genome shotgun high-throughput sequencing. Our results show that Ceraceosorus is the only sampled fungal genus in Ustilaginomycotina with significant intragenomic variation at the ITS, with up to 25 nucleotide variant sites in the ITS1–5.8S–ITS2 region and 2.6% divergence among analyzed ITS haplotypes. We found many conflicting patterns across the three detection methods, with up to 27 conflicting variant sites recorded from a single individual. At least 40% of the conflicting patterns are possibly due to PCR-cloning-sequencing errors, as the corresponding variant sites were not observed in the other detection methods. Based on our data and the literature, we evaluated the characteristics and advantages/disadvantages of each detection method. Finally, a model for how intragenomic variation in the rDNA copies within a genome may arise is presented.

Botryobasidium bambusinum (Botryobasidiaceae, Cantharellales): a new species from Yunnan, Southwest China, based on morphology and phylogeny

ABSTRACT Botryobasidium bambusinum sp. nov. was collected in Yunnan Province, China, is described here as a new species based on its morphology and phylogeny. In this study, the taxon Botryobasidium bambusinum is characterised by its resupinate, coriaceous conidiomata with a smooth, hypochnoid, rubiginous to slightly reddish-brown hymenial surface, a slightly thick-walled basal hyphae with simple septa, subcylindrical, septate subglobose to globose, slightly thick-walled conidia measuring as 7.2–9.5 × 7–9 µm. Phylogenetic analyses of the new species were based on the internal transcribed spacer (ITS) and large subunit (nrLSU) of ribosomal DNA (rDNA) sequences. The phylogenetic tree indicated that the new species belonged to the genus Botryobasidium, and was closely related to B. gossypirubiginosum, B. rubiginosum and B. simile. Botryobasidium gossypirubiginosum differs from B. bambusinum by having a floccose to cotton conidiomata. Botryobasidium rubiginosum differentiates from B. bambusinum by having a cottony conidiomata, and ovoid to ellipsoid, larger conidia (14.5–16 × 10.5–12.5 µm vs 7.2–9.5 × 7–9 µm). Botryobasidium simile can be distinguished from B. bambusinum by having an ochraceous to fulvous conidiomata, and larger conidia (21.5–27 × 16–18 µm vs 7.2–9.5 × 7–9 µm). A detailed description, illustrations and phylogenetic analysis of the new species are provided.

Dissemination of antibiotic-resistant bacteria associated with microplastics collected from Monastir and Mahdia coasts (Tunisia)

The exponential use of plastics and their recalcitrant nature leads to their significant accumulation in the environment. The occurrence of plastic wastes is considered as a serious environmental problem. Additionally, plastic wastes can break down into smaller pieces called microplastics (MPs), leading to further interactions with the environment and living organisms. In this study, sixty-six strains were isolated from microplastic particles collected on different coastal areas of Monastir and Mahdia (Tunisia). The different bacterial isolates were identified according to some biochemical tests such as catalase, oxidase, and were subjected to molecular characterization. Amplification of the internal transcribed spacer (ITS) revealed the presence of 31 ITS haplotypes. The partial sequencing of the 16S ribosomal DNA of representative strains was analyzed. The majority of bacterial isolates (84.31 %) belonged to Gamma-proteobacteria (84.78 %), while the remaining isolates were affiliated to Firmicutes (15.21 %). The microplastic-associated bacterial isolates belonged to 10 genera, namely Acinetobacter, Pseudomonas, Bacillus, Staphylococcus, Shewanella, Aeromonas, Vibrio, Stutzerimonas, Exiguobacterium, Enterobacter. Among the well-represented Acinetobacter genus, the most common species identified was Acinetobacter johnsonii. Susceptibility patterns of these strains were studied against 21 antibiotics commonly used in Tunisia. A high level of antibiotic resistance was observed for Penicillin G (97.82 %) and Temocillin (86.95 %). S26 strain presented the highest multidrug resistance with a multiple antibiotic resistance (MAR) index of 0.71.

Mahonia nanlingensis (Berberidaceae), a new species from China

Mahonia nanlingensis (Berberidaceae), a new species from Nanling Mountains in China, is described and illustrated. It is distinguished morphologically from allied species by its 7–9 fine-toothed leaflets, the rounded or cordate apex of the outer sepals, narrowly incised apex of petals, truncate stamen anthers and broadly discoid stigma. Phylogenetic analysis based on chloroplast and nuclear ribosomal DNA (nrDNA) sequences further supports its recognition as a new species. Due to habitat disturbance and medicinal use, M. nanlingensis is assessed as “Vulnerable” (VU) according to the IUCN Red List categories and criteria.

NAMERS: a purpose-built reference DNA sequence database to support applied eDNA metabarcoding

Applied eDNA metabarcoding is increasingly being considered as a tool to inform management decisions, regulations, or policy development. Because these downstream considerations are coming to the forefront of eDNA applications, optimizing workflow elements is essential to increasing standardization, efficiency, and competency of metabarcoding results. Reference DNA sequences are critical workflow elements that currently lack consistent approaches to generating, curating, or publishing. We present a complete mitochondrial genome and nuclear ribosomal DNA cistron reference DNA sequence library for 92% of the freshwater fish species of British Columbia, Canada. This resource is published as the Novel Applied eDNA Metabarcoding Reference Sequences (NAMERS) repository (https://namers.ca), a user-friendly and interactive website for specialists and non-specialists alike to explore and generate custom reference libraries for taxa and genes of interest. We demonstrate the power of NAMERS for optimization of applied eDNA metabarcoding study design by analyzing the number of primer mismatches and species resolution power of existing metabarcoding markers. NAMERS demonstrates that high quality curated genomic information is within a reasonable reach to meet the increasing demand for actionable eDNA metabarcoding applications. The framework used here incorporating the pillars of accuracy, completeness and accessibility can be applied for new iterations of other reference sequence databases to bring DNA-based monitoring into a new era.

Hemicycliophora potteri n. sp. (Tylenchida: Hemicycliophoridae) infesting highbush blueberry (Vaccinium corymbosum) in Ontario, Canada

Summary Highbush blueberry is a blueberry species native to North America and is a food crop of significant economic importance for Canada. Plant-parasitic nematodes are known to infest this crop. Species of Hemicycliophora, commonly known as sheath nematodes, are obligatory plant-parasites, and some cause diseases on a wide range of crops. A population of Hemicycliophora of high number was found in highbush blueberry fields in Norfolk and Middlesex counties of southwestern Ontario. Following through morphological and molecular studies, this population was determined a new species as Hemicycliophora potteri n. sp. This species is characterised by its outer sheath adpressed fitting to the body, lateral fields with diagonal connections of transverse striae, amphid apertures covered by lateral plates, lip region slightly set-off with four annuli; excretory pore anterior to the base of the pharynx, stylet knob cavity moderate, vulva lips modified, tail tapering gradually and more abruptly towards the last one-third, and no males were found. Molecularly, the 18S, and 28S ribosomal DNA sequences are most similar to those of H. thienemanni, H. similis, H. gracilis, and a few unidentified species. A dichotomous key for the diagnostic of the species of Hemicycliophora in Canada was presented. To the best of our knowledge, Hemicycliophora potteri n. sp. is the first recorded species of the genus to be named and fully described from highbush blueberry.

Occurrence of Chiorchis fabaceus (Trematoda: Cladorchiidae) in a wild Antillean manatee (Trichechus manatus manatus): New parasitological data for this imperilled sirenian

Parasites impact wildlife populations and ecosystem health, thereby demanding regular monitoring. As part of the national conservation effort to preserve the free-ranging sirenians in Colombia, a parasitological survey was conducted between 2011 and 2023 on naturally deceased Antillean manatees (Trichechus manatus manatus). A total of 17 stranded carcasses were analysed for the occurrence of parasites. Herein, trematode adult stages were recovered from the stomach, small intestine, caecum and colon of an adult male manatee and microscopically analysed. Additionally, molecular analysis was conducted based on an almost complete coding sequence of the ITS1–5.8S-ITS2, partial sequence of 18S and 28S ribosomal DNA (rDNA) genes. Phylogenetic analysis clustered the trematode sequences within Chiorchis fabaceus species, thus constituting the first adult-based sequences isolated for the species. Presented data contribute to a better understanding of the sirenian parasite diversity.

Molecular phylogeny, phenolics content, and antimicrobial activity of some potential medicinal plant species of the Fabaceae family collected from different geographical regions of Saudi Arabia

The molecular identification and taxonomic classification of medicinal plants are essential using various molecular markers for their accurate identification, safe utilization, and genetic conservation. The internal transcribed spacer sequence of nuclear ribosomal DNA (nrDNA-ITS) revealed the clustering of collected plant species into various clades according to their sequence similarity. The estimated total phenolic content (TPC) and total flavonoid content (TFC) in the leaves of different plant species ranged from 29.98 to 80.28 mg GAE/g DW, and 26.39 to 60.45 mg QE/g DW, respectively. Among the plant species, the content of bioactive compounds, luteolin 7-rutinoside and quercetin 3-β-D-glucoside were observed to be highest in Anagyris foetida, whereas p-coumaric acid was observed to be greatest in Astragalus spinosus. Among all plant species extracts tested, Anagyris foetida extract (AFE), Astragalus spinosus extract (ASPE), and Astragalus sieberi extract (ASIE) exhibited significant activities against the Escherichia coli (E. coli) strain, mainly AFE showed more effective activity against the E. coli pathogen (MIC-6.25 µg/mL and MBC-12.50 µg/mL). Thus, screened plant extracts of different species could be tested on other microorganisms to explore their medicinal properties to cure various diseases against pathogens as well as their application in the food industry as a food preservative.

Fasciolopsis buski isolated from human host, India has distinct clade based on nuclear ribosomal DNA sequences

Fasciolopsiasis caused by Fasciolopsis buski, is a significant cause of morbidity. In the present study F. buski detected during endoscopy of a 50-year-old male patient form Uttar Pradesh, India was used for phylogenetic analysis based on 28S rDNA and ITS2 regions. The parasite was genetically similar to an isolate of pig from Meghalaya. The intra-species genetic variation for 28S rDNA was 1–3% (India), 5% (Vietnam) and for ITS2, 1–2% (India) while 17 % from Vietnam. Thus, F. buski from humans or pigs from India were closely related than those from Vietnam and China which were grouped into separate clades.

New insights into the phylogenetic relationships within the Lauraceae from mitogenomes

BackgroundThe family Lauraceae is subdivided into six main lineages: Caryodaphnopsideae, Cassytheae, Cryptocaryeae, Hypodaphnideae, Laureae, and Neocinnamomeae. However, phylogenetic relationships among these lineages have been debatable due to incongruence between trees constructed using nuclear ribosomal DNA (nrDNA) sequences and chloroplast (cp) genomes. As with cp DNA, the mitochondrial (mt) DNA of most flowering plants is maternally inherited, so the phylogenetic relationships recovered with mt genomes are expected to be consistent with that from cp genomes, rather than nrDNA sequences.ResultsThe mitogenome of Machilus yunnanensis, with a length of 735,392 bp, has a very different genome size and gene linear order from previously published magnoliid mitogenomes. Phylogenomic reconstructions based on 41 mt genes from 92 Lauraceae mitogenomes resulted in highly supported relationships: sisterhood of the Laureae and a group containing Neocinnamomeae and Caryodaphnopsideae, with Cassytheae being the next sister group, followed by Cryptocaryeae. However, we found significant incongruence among the mitochondrial, chloroplast, and nuclear phylogenies, especially for the species within the Caryodaphnopsideae and Neocinnamomeae lineages. Time-calibrated phylogenetic analyses showed that the split between Caryodaphnopsideae and Neocinnamomeae dated to the later Eocene, around 38.5 Ma, Laureae originated in the Late Cretaceous, around 84.9 Ma, Cassytheae originated in the mid-Cretaceous around 102 Ma, and Cryptocaryeae originated in the Early Cretaceous around 116 Ma. From the Late Cretaceous to the Paleocene, net diversification rates significantly increased across extant clades of major lineages, and both speciation rates and net diversification rates continued steady growth towards the present.ConclusionsThe topology obtained here for the first time shows that mt genes can be used to support relationships among lineages of Lauraceae. Our results highlight that both Caryodaphnopsideae and Neocinnamomeae lineages are younger than previously thought, likely first diversifying in the Eocene, and species in the other extant lineages of Lauraceae dates in a long-time span from the Early Cretaceous to the Eocene, and the climate of a period of about 90 million years was relatively warm, while the extant species of Lauraceae then continuously diversified with global cooling from the Eocene to the present day.

Morphological and molecular identification of Asterostroma roseoalbum sp. nov. (Peniophoraceae, Russulales), from southwestern China

ABSTRACT Asterostroma roseoalbum sp. nov. was found in Yunnan Province, China, is described here as a new species based on its morphology and phylogeny. Asterostroma roseoalbum is characterised by its felted-membranous to pellicular, fimbriate basidiomata with a smooth hymenophore and a dimitic hyphal system bearing generative hyphae with simple-septate and echinulate, subglobose to globose basidiospores measuring as 8–9.5 × 7–9 µm. Phylogenetic analyses of the new species were based on the internal transcribed spacer (ITS) and large subunit (nrLSU) of ribosomal DNA (rDNA) sequences. The phylogenetic analysis indicated that the new species belongs to the genus Asterostroma, and is closely related to two species A. macrosporum and A. muscicola. A full description, illustrations and phylogenetic analysis results of the new species are provided. Furthermore, a key to the genus Asterostroma in China is provided.

Impact of periodontal therapy on oral bacterial composition in individuals diagnosed with advanced periodontal disease.

Introduction. Negative changes in the microbial composition have been extensively studied in individuals with periodontal disease.Gap Statement. The changes in the oral microbiota after treating this disease are still unknown.Aim. We sought to elucidate the distinctive traits of salivary microbiota in individuals displaying healthy gums and those with severe periodontitis (SP) and examine the influence of periodontal therapy.Methodology. Periodontal pocket depths were examined to determine disease severity. The presence and quantity of oral Helicobacter pylori (associated with periodontal disease) were determined. Sequencing of 16S ribosomal DNA and bioinformatic analyses were performed to assess oral bacterial compositions in patients.Results. Sequencing analysis of 16S ribosomal DNA revealed a significant reduction in the abundance of operational taxonomic units (OTUs) and Chao1 and Abundance coverage-based estimator(ACE) indices in the oral cavities of individuals with SP compared to those of the healthy controls. However, these parameters showed significant recovery after appropriate treatment severe periodontitis after treatment (TSP). Additionally, the levels of harmful Bacillales and Spirochetes significantly increased, whereas the presence of beneficial Euryarchaeota significantly decreased in the SP group. The TSP group exhibited considerably augmented abundances of Burkholderiaceae and Veillonella, while noteworthy reductions in the pathogenic microbiota (Clostridia, Fusobacteria and Spirochaetes) were noticed compared to those of the SP group. Functionally, these modified OTUs were extensively implicated in 41 metabolic pathways.Conclusion. Our study demonstrates that nonsurgical periodontal therapy can effectively reduce the diversity of the oral microbiota, thereby potentially enhancing the treatment efficacy in patients with periodontal disease.

Stability of Gastric Fluid and Fecal Microbial Populations in Healthy Horses under Pasture and Stable Conditions.

Equine gastrointestinal microbial communities vary across the gastrointestinal tract and in response to diet or disease. Understanding the composition and stability of gastric fluid microbiota in healthy horses is a prerequisite to understanding changes associated with the development of disease. The objective of this study was to describe microbial communities in the gastric fluid and feces of healthy horses longitudinally. Horses were maintained on pasture (6 weeks), stabled (5 weeks), then returned to pasture. A consistent forage diet was provided throughout. Native gastric fluid and feces were collected weekly for full-length 16S ribosomal DNA sequencing and microbial profiling analysis. Fewer taxa were identified in the gastric fluid (770) than in the feces (5284). Species richness and diversity were significantly different between sample types (p < 0.001), but not between housing locations (p = 0.3). There was a significant effect of housing and horse on the Bray-Curtis compositional diversity of gastric (p = 0.005; p = 0.009) and fecal (p = 0.001; p = 0.001) microbiota. When horses moved from pasture to stable, the relative proportions of gastric fluid Lactobacillaceae increased and Streptococcaceae decreased, while fecal Firmicutes increased and Bacteriodota decreased. Within each housing condition, there was no significant week-to-week variation in gastric (p = 0.9) or fecal (p = 0.09) microbiota. Overall, these findings support the maintenance of stable gastric and fecal microbial populations under each management condition, providing a basis for further investigation of gastric fluid microbiota in diseases of the foregut.

First European records of Puccinia modiolae and P. platyspora, two native South American rust fungi, and new observations on their life cycle and morphology

ABSTRACT This paper reports the South American rust fungi Puccinia modiolae and P. platyspora (Pucciniales/Uredinales) as new alien species of the European rust funga. Puccinia modiolae is presently known from Switzerland and Germany, P. platyspora from Switzerland, Germany, and France. The records of P. platyspora are the first ones from outside South America. The specimens were identified by teliospore characters and sequences of the nuclear ribosomal DNA (internal transcribed spacer 2 and domains D1–D2 of the nuclear ribosomal large subunit) and the mitochondrial CO3 (cytochrome c oxidase III) gene. Puccinia modiolae and P. platyspora have been recorded so far in Europe on members of the genera Alcea, predominantly on Alcea rosea, Althaea, and Malva of the Malvaceae, subfam. Malvoideae. Alcea rosea is host of both species and shared also with the common mallow rust, P. malvacearum, allowing for mixed infections. The plant is commonly grown as an ornamental and may play a major role for the spread of the alien Malvaceae rust fungi. It was observed for the first time that P. platyspora can produce spermogonia and aecidium-type aecia, suggesting phenotypic plasticity regarding the formation of spore states. The observed spermogonia mainly remained closed and did not liberate spermatia. They produced telio- and aeciospores besides spermatia in their cavity and eventually converted entirely into telia or, rarely, into aecidium-like sori. Small clusters of aeciospores and peridial cells were commonly found hidden in the telial plectenchyma, and well-developed aecidium-type aecia provided with a peridium developed rarely in the center of mature telia. Spermogonia belonging to group V type 4 were found in P. malvacearum, which is generally supposed to lack spermogonia. Some spermogonia produced only spermatia in their cavity; others formed spermatia and teliospores, and some eventually converted into telia.