16S rRNA Gene Analysis Research Articles

From ctenophores to scyphozoans: parasitic spillover of a burrowing sea anemone

Most host-parasite associations are explained by phylogenetically conservative capabilities for host utilization, and therefore parasite switches between distantly related hosts are rare. Here we report the first evidence of a parasitic spillover of the burrowing sea anemone Edwardsiella carnea from the invasive ctenophore Mnemiopsis leidyi to two scyphozoan hosts: the native Mediterranean barrel jellyfish Rhizostoma pulmo and the invasive Indo-Pacific nomad jellyfish Rhopilema nomadica, collected from the Eastern Mediterranean Sea. Edwardsiella carnea planulae found in these jellyfish were identified using molecular analyses of the mitochondrial 16S and nuclear 18S rRNA genes. Overall, 93 planulae were found on tentacles, oral arms, and inside of the gastrovascular canals of the scyphomedusae, whereas no infection was observed in co-occurring ctenophores. DNA metabarcoding approach indicated seasonal presence of Edwardsiella sp. in the Eastern Mediterranean mesozooplankton, coinciding with jellyfish blooms in the region. Our findings suggest a non-specific parasitic relationship between Edwardsiella carnea and various gelatinous hosts based on shared functionality rather than evolutionary history, potentially driven by shifts in host availability due to jellyfish blooms. This spillover raises questions about the ecological impacts of parasitism on native and invasive scyphozoan hosts and the potential role of Edwardsiella in controlling their populations.

Reclassification of Butyrivibrio crossotus Moore et al. 1976 (Approved Lists 1980) into a novel genus as Eshraghiella crossota gen. nov., comb. nov.

The reclassification of Butyrivibrio crossotus Moore et al. 1976 (Approved Lists 1980) as Eshraghiella crossota gen. nov., comb. nov. is proposed within the family Lachnospiraceae. This reclassification is based on differences revealed through the analysis of 16S rRNA, groEL, recA, and rpoB genes, as well as genome sequences, distinguishing it from other Butyrivibrio species. Comparative analysis showed that B. crossotus exhibited digital DNA-DNA hybridization (dDDH) values of 19.40-27.20% and average nucleotide identities based on blast (ANIb) values of 67.06-67.64% with other Butyrivibrio species. These values are significantly below the species delineation thresholds (dDDH, 70%; ANIb, 95-96%), justifying the proposed reclassification. Additionally, the results of the average amino acid identity (AAI) analysis indicated that this species shares 59.22-60.17% AAI with the other species of the genus Butyrivibrio, which is below the AAI threshold (65%) for a genus boundary. In addition, biochemical and morphological characteristics also support the proposal that this species is different from other species of the genus Butyrivibrio. The type strain is ATCC 29175T (DSM 2876T=T9-40AT).

Exploring Indonesian actinomycete extracts for anti-tubercular compounds: Integrating inhibition assessment, genomic analysis, and prediction of its target by molecular docking

Tuberculosis (TB) is the foremost cause of infectious fatality globally. The primary global challenge in combatting TB lies in addressing the emergence of drug-resistant variants of the disease. However, the number of newly approved agents for treating TB has remained remarkably low over recent decades. Hence, research endeavors for discovering novel anti-TB agents are always needed. In the present study, we screened over 1,500 culture extracts from actinomycetes isolated in Indonesia for their inhibitory activity against Mycobacterium smegmatis used as a surrogate in the primary screening. The initial screening yielded approximately 6.2 % hit extracts, with a selection criterion of >80 % growth inhibition. The confirmed hit extracts were subsequently subjected to growth inhibition assay against Mycobacterium bovis and Mycobacterium tuberculosis. Approximately 20 % of the hit extracts that showed growth inhibition also exhibited efficacy against M. bovis BCG and M. tuberculosis H37Rv pathogenic strain. An active compound was successfully purified from a large-scale culture of the most potent representative extract by high-performance liquid chromatography and thin-layer chromatography. The structure of the active compound was elucidated by mass spectrometry and nuclear magnetic resonance. This compound displayed structural similarities to actinomycin group and exhibited robust inhibition, with IC50 values of 0.74, 0.02, and 0.07 μg/mL against M. smegmatis, M. bovis, and M. tuberculosis, respectively. The Actinomycetes strain A612, which produced the active compound, was taxonomically classified by phylogenetic analysis of 16s rRNA gene and whole genome sequencing data as Streptomyces parvus. Computational genome analysis utilizing anti-SMASH 7.0 unveiled that S. parvus A612 strain harbors 40 biosynthetic gene clusters with the potential to produce 16 known (with >70 % similarity) and 24 unknown compounds. A non-ribosomal peptide synthesis (NRPS) gene cluster associated with actinomycin D biosynthesis was also identified, boasting an 85 % similarity. Molecular docking analysis of actinomycin D and 21 potential M. tuberculosis targets revealed possible interactions with multiple targets. The purified active compound inhibited recombinant M. tuberculosis shikimate kinase (MtSK), which validated the results obtained from the docking analysis.

Distinct changes in tomato-associated multi-kingdom microbiomes during Meloidogyne incognita parasitism

BackgroundThe interplay between root-knot nematode (RKN) parasitism and the complex web of host-associated microbiota has been recognized as pivotal for effective management of the pest. However, studies assessing this relationship have focussed on the bacterial and fungal communities, neglecting the unicellular eukaryotic members. Here, we employed amplicon sequencing analysis of the bacterial 16S rRNA, fungal ITS and eukaryotic 18S rRNA genes, and comprehensively examined how the microbiome composition, diversity and networking developed with time in the rhizospheres and roots of RKN-inoculated and non-inoculated tomato plants.ResultsAs expected, infection with the RKN Meloidogyne incognita decreased plant growth. At individual timepoints, we found distinct bacterial, fungal and eukaryote community structures in the RKN-inoculated and non-inoculated rhizospheres and roots, and RKN inoculation affected several taxa in the root-associated microbiome differentially. Correlation analysis revealed several bacterial and fungal and few protist taxa that correlated negatively or positively with M. incognita. Moreover, network analysis using bacterial, fungal and eukaryotic data revealed more dynamic networks with higher robustness to disturbances in the RKN-inoculated than in the non-inoculated rhizospheres/roots. Hub taxa displayed a noticeable successional pattern that coincided with different phases of M. incognita parasitism. We found that fungal hubs had strong negative correlations with bacteria and eukaryotes, while positive correlations characterized hub members within individual kingdoms.ConclusionOur results reveal dynamic tomato-associated microbiomes that develop along different trajectories in plants suffering M. incognita infestation and non-infested plants. Overall, the results identify stronger associations between RKN and bacterial and fungal taxa than between eukaryotic taxa and RKN, suggesting that fungal and bacterial communities could play a larger role in the regulation of RKN. The study identifies several putative RKN-antagonistic bacterial and fungal taxa and confirms the antagonistic potential previously identified in other taxa.

Ubiquity of methanogenic archaea in the trunk of coniferous and broadleaved tree species in a mountain forest.

Wetwood of living trees is a habitat of methanogenic archaea, but the ubiquity of methanogenic archaea in the trunk of various trees has not been revealed. The present study analysed methanogenic archaeal communities inside coniferous and broadleaved trees in a cold temperate mountain forest by culture-dependent or independent techniques. Heartwood and sapwood segments were obtained from the trunk of seven tree species, Cryptomeria japonica, Quercus crispula, Fraxinus mandshurica, Acer pictum, Aesculus turbinata, Magnolia obovata, and Populus tremula. Amplicon sequencing analysis of 16S rRNA genes showed that Methanobacteriaceae predominated the archaeal communities and Methanomassiliicoccaceae also inhabited some trees. Real-time PCR analysis detected methanogenic archaeal mcrA genes from all the tree species, with a maximum of 107copiesg-1 dry wood. Digital PCR analysis also detected mcrA genes derived from Methanobacterium spp. and Methanobrevibacter spp. from several samples, with a maximum of 105 and 104copiesg-1 dry wood. The enumeration by the most probable number method demonstrated the inhabitation of viable methanogenic archaea inside the trees; 106cellsg-1 dry wood was enumerated from a heartwood sample of C. japonica. Methanogenic archaea related to Methanobacterium beijingense were cultivated from a heartwood sample of Q. crispula and F. mandshurica. The present study demonstrated that the inside of various trees is a common habitat for methanogenic archaeal communities and a potential source of methane in forest ecosystems.

Methane-Driven Perchlorate Reduction by a Microbial Consortium.

The phenomenon of methane oxidation linked to perchlorate reduction has been reported in multiple studies; yet, the underlying microbial mechanisms remain unclear. Here, we enriched suspended cultures by performing methane-driven perchlorate reduction under oxygen-limiting conditions in a membrane bioreactor (MBR). Batch test results proved that perchlorate reduction was coupled to methane oxidation, in which acetate was predicted as the potential intermediate and oxygen played an essential role in activating methane. By combining DNA-based stable isotope probing incubation and high-throughput sequencing analyses of 16S rRNA gene and functional genes (pmoA, pcrA, and narG), we found that synergistic interactions between aerobic methanotrophs (Methylococcus and Methylocystis) and perchlorate-reducing bacteria (PRB; Denitratisoma and Dechloromonas) played active roles in mediating methane-driven perchlorate reduction. This partnership was further demonstrated by coculture experiments in which the aerobic methanotroph could produce acetate to support PRB to complete perchlorate reduction. Our findings advance the understanding of the methane-driven perchlorate reduction process and have implications for similar microbial consortia linking methane and chlorine biogeochemical cycles in natural environments.

Description of Babesiacoryicola sp. nov. from Florida pumas (Puma concolor coryi) from southern Florida, USA

Previously, a high prevalence of piroplasms has been reported from Florida pumas (Puma concolor coryi) from southern Florida. In the current study, we describe the biological characteristics of a novel Babesia species in Florida pumas. Ring-stage trophozoites were morphologically similar to trophozoites of numerous small babesids of felids including B. leo, B. felis, and Cytauxzoon felis. Parasitemias in Florida pumas were very low (<1%) and hematologic values of 25 Babesia-infected Florida pumas were within normal ranges for P. concolor. Phylogenetic analysis of near full-length 18S rRNA gene, β-tubulin, cytochrome c oxidase subunit I, cytochrome c oxidase subunit III, and cytochrome b gene sequences indicated that this Babesia species is a member of the Babesia sensu stricto clade and is related to groups of Babesia spp. from carnivores or ungulates, although the closest group varied by gene target. Internal transcribed spacer (ITS)-1 region sequences from this Babesia sp. from 19 Florida pumas were 85.7–99.5% similar to each other and ∼88% similar to B. odocoilei. Similarly, an ITS-2 sequence from one puma was 96% similar to B. bigemina and 92% similar to a Babesia sp. from a red panda (Ailurus fulgens). Infected pumas were positive for antibodies that reacted with B. odocoilei, B. canis, and B. bovis antigens with titers of 1:256, 1:128, and 1:128, respectively. No serologic reactivity was noted for Theileria equi. No molecular evidence of congenital infection was detected in 24 kittens born to 11 Babesia-infected female pumas. Pumas from other populations in the United States [Louisiana (n = 1), North Dakota (n = 5) and Texas (n = 28)], British Columbia, Canada (n = 9), and Costa Rica (n = 2) were negative for this Babesia sp. Collectively, these data provide morphologic, serologic, genetic, and natural history data for this novel Babesia sp. which we propose the name Babesia coryicola sp. nov. sp. This is the first description of a felid-associated Babesia species in North America.

Incidence and pathological effects during encysted progenetic Euclinostomum heterostomum metacercariae infection in the freshwater fish spotted snakehead (Channa punctatus)

Aim: To assess the incidence and pathological effects during encysted progenetic Euclinostomum heterostomum metacercariae infestation in the freshwater fish spotted snakehead (Channa punctatus). Methodology: Samples of Channa punctatus were collected from Tilaiya Reservoir, Koderma, Jharkhand, India, during pre-monsoon, monsoon, and post-monsoon seasons. The encysted metacercariae trematodes were isolated from Channa punctatus. Characterization was performed based on the morphology and sequencing analysis of a partial 18S rRNA gene. Further, the kidney and liver samples from infected fish were subjected to histopathological studies. Prevalence, abundance, and Intensity of infection were further determined. Results: Morphological identification suggests that the encysted metacercariae belonged to Digenean trematodes of genera Euclinostomum, and amplification of partial sequence of 18S rRNA, and phylogenetic analysis revealed the isolated metacercariae were Euclinostomum heterostomum. The histopathological study of the kidney showed hepatocyte degeneration, cytoplasmic vacuolation, and nuclear transformations. Liver fibrosis was observed in Channa punctatus. The prevalence during pre-monsoon, monsoon, and post-monsoon season ranged from 66.1% to 81.1%, abundance from 0.74 to 0.92, and intensity ranged from 1 to 1.14 using the Margolis formula. Interpretation: The study highlights the infestation of Euclinostomum heterostomum in Channa punctatus during the pre- monsoon climate appears favorable for the abundance of parasites. Hence, a proper inspection before consumption is necessary. Key words: Euclinostomum heterostomum, Infestation, Metacercariae, Parasites, Progenetic infection

Winter cover crop suppression methods influence on sunflower growth and rhizosphere communities.

Sunflower (Helianthus annuus L.), a vital crop for global vegetable oil production, encounters sustainability challenges in its cultivation. This study assesses the effects of incorporating a winter cover crop (CC), Avena sativa (L.), on the subsequent growth of sunflower crops and the vitality of their rhizosphere microbial communities over a two-year period. It examines the impact of two methods for suppressing winter CC-chemical suppression using glyphosate and mechanical suppression via rolling-both with and without the addition of phosphorus (P) starter fertilizer. These approaches are evaluated in comparison to the regional best management practices for sunflower cultivation, which involve a preparatory chemical fallow period and the subsequent application of starter P fertilizer. The methodology utilized Illumina sequencing for the analysis of rhizosphere bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) amplicons. Findings indicate a significant improvement (9-37%) in sunflower growth parameters (plant height, stem diameter, head diameter, and head dry weight) when cultivated after glyphosate-suppressed winter CC compared to the chemical fallows. Conversely, rolling of winter CC generally negatively affected sunflower growth. Rhizosphere bacterial communities following chemical suppression of winter CC showed greater Pielou's evenness, indicating a uniform distribution of species. In general, this treatment had more detrimental effects on beneficial sunflower rhizosphere bacteria such as Hymenobacter and Pseudarthrobacter than rolling of the winter CC, suggesting that the overall effect on sunflower growth may be mitigated by the redundancy within the bacterial community. As for fungal diversity, measured by the Chao-1 index, it increased in sunflowers planted after winter CC and receiving P fertilization, underscoring nutrient management's role in microbial community structure. Significant positive correlations between fungal diversity and sunflower growth parameters at the reproductive stage were observed (r = 0.41-0.72; p < 0.05), highlighting the role of fungal communities in plant fitness. The study underscores the positive effects of winter CC inclusion and management for enhancing sunflower cultivation while promoting beneficial microbes in the crop's rhizosphere. We advocate for strategic winter CC species selection, optimization of mechanical suppression techniques, and tailored phosphorus fertilization of sunflower to foster sustainable agriculture.

Sequencing approaches to identify distal jejunum microbial community composition and function in broiler chickens fed anti-interleukin-10 during coccidiosis and necrotic enteritis challenge

Strategies to counteract interleukin (IL)-10-mediated immune evasion by Eimeria spp. during coccidiosis- like anti-IL-10 antibodies- may protect broiler chicken health and reduce incidence of secondary necrotic enteritis (Clostridium perfringens) via undetermined mechanisms. Objectives were to use sequencing techniques to evaluate jejunal microbial community composition and function in anti-IL-10-fed broilers during coccidiosis and necrotic enteritis. On d0, Ross 308 chicks were placed in 32 cages (15 chicks/ cage) for a 25-d study and randomly assigned to diets ± 0.03% anti-IL-10. Six chicks/ diet were euthanized for distal jejunum content and tissue collection on d 14 (baseline) before inoculating the remainder with saline or 15,000 E. maxima oocysts (M6 strain). Half the chicks challenged with E. maxima were challenged with C. perfringens (1×108 colony forming units) on d 18 and 19. Follow-up samples (6 chicks/treatment) were collected at 7 and 11 d postinoculation (pi) for the E. maxima-only group, or 3 and 7 dpi for the E. maxima + C. perfringens group with 3/7 dpi being designated as peak and 7/11dpi as postpeak challenge. DNA was extracted from digesta for microbiota composition analysis (16S rRNA gene sequencing) while RNA was extracted from tissue to evaluate the metatranscriptome (RNA sequencing). Alpha diversity and genus relative abundances were analyzed using the diet or challenge main effects with associated interactions (SAS 9.4; P ≤ 0.05). No baseline microbial changes were associated with dietary anti-IL-10. At peak challenge, a diet main effect reduced observed species 36.7% in chicks fed anti-IL-10 vs. control; however, the challenge effect reduced observed species and Shannon diversity 51.2-58.3% and 33.0 to 35.5%, respectively, in chicks challenged with E. maxima ± C. perfringens compared to their unchallenged counterparts (P ≤ 0.05). Low sequencing depth limited metatranscriptomic analysis of jejunal microbial function via RNA sequencing. This study demonstrates that challenge impacted the broiler distal jejunum microbiota more than anti-IL-10 while future research to characterize the microbial metatranscriptome may benefit from investigating other intestinal compartments.

D-Pinitol Improves Diabetic Sarcopenia by Regulation of the Gut Microbiome, Metabolome, and Proteome in STZ-Induced SAMP8 Mice.

d-Pinitol (DP) is primarily found in Vigna sinensis, which has been shown to have hypoglycemic and protective effects on target organs. However, the mechanism of DP in treating diabetic sarcopenia (DS) is still unclear. To explore the underlying mechanism of DS and the protective targets of DP by high-throughput analysis of 16S rRNA gene, metabolome, and the proteome. Streptozotocin-induced SAMP8 mice were intragastrically administrated DP (150 mg/kg) for 8 weeks. Fecal 16S rRNA gene sequencing and gastrocnemius muscle metabolomic and proteomic analyses were completed to investigate the gut-muscle axis interactions. DP significantly alleviated the muscle atrophy in diabetic mice. Dysfunction of the gut microbiota was observed in the DS mice. DP significantly reduced the Parabacteroides, Akkermansia, and Enterobacteriaceae, while it increased Lachnospiraceae_NK4A136. Metabolome and proteome revealed that 261 metabolites and 626 proteins were significantly changed in the gastrocnemius muscle of diabetic mice. Among these, DP treatment restored 44 metabolites and 17 proteins to normal levels. Functional signaling pathways of DP-treated diabetic mice included nucleotide metabolism, β-alanine, histidine metabolism, ABC transporters, and the calcium signaling pathway. We systematically explored the molecular mechanism of DS and the protective effect of DP, providing new insights that may advance the treatment of sarcopenia.

Analysis of Oral and Gut Microbiome Composition and Its Impact in Patients with Oral Squamous Cell Carcinoma.

The impact of gut and oral microbiota on the clinical outcomes of patients with oral squamous cell carcinoma (OSCC) is unknown. We compared the bacterial composition of dental plaque and feces between patients with OSCC and healthy controls (HCs). Fecal and dental plaque samples were collected from 7 HCs and 18 patients with OSCC before treatment initiation. Terminal restriction fragment-length polymorphism analysis of 16S rRNA genes was performed. Differences in bacterial diversity between the HC and OSCC groups were examined. We compared the occupancy of each bacterial species in samples taken from patients with OSCC and HCs and analyzed the correlation between PD-L1 expression in the tumor specimens and the occupancy of each bacterial species. The gut and oral microbiota of patients with OSCC were more varied than those of HCs. Porphyromonas and Prevotella were significantly more abundant in patients with OSCC than in HCs. The abundance of Clostridium subcluster XIVa in the gut microbiota of the PD-L1-positive group was significantly greater than that in the PD-L1-negative group. The oral and gut microbiomes of patients with OSCC were in a state of dysbiosis. Our results suggest the possibility of new cancer therapies targeting these disease-specific microbiomes using probiotics and synbiotics.

Pseudomonas and Pseudarthrobacter are the key players in synergistic phenanthrene biodegradation at low temperatures

Hydrocarbon contamination, including contamination with polycyclic aromatic hydrocarbons (PAHs), is a major concern in Antarctica due to the toxicity, recalcitrance and persistence of these compounds. Under the Antarctic Treaty, nonindigenous species are not permitted for use in bioremediation at polluted sites in the Antarctic region. In this study, three bacterial consortia (C13, C15, and C23) were isolated from Antarctic soils for phenanthrene degradation. All isolated bacterial consortia demonstrated phenanthrene degradation percentages ranging from 45 to 85% for 50 mg/L phenanthrene at 15 ℃ within 5 days. Furthermore, consortium C13 exhibited efficient phenanthrene degradation potential across a wide range of environmental conditions, including different temperature (4–30 ℃) and water availability (without polyethylene glycol (PEG) 6000 or 30% PEG 6000 (w/v)) conditions. Sequencing analysis of 16S rRNA genes revealed that Pseudomonas and Pseudarthrobacter were the dominant genera in the phenanthrene-degrading consortia. Moreover, six cultivable strains were isolated from these consortia, comprising four strains of Pseudomonas, one strain of Pseudarthrobacter, and one strain of Paeniglutamicibacter. These isolated strains exhibited the ability to degrade 50 mg/L phenanthrene, with degradation percentages ranging from 4 to 22% at 15 ℃ within 15 days. Additionally, the constructed consortia containing Pseudomonas spp. and Pseudarthrobacter sp. exhibited more effective phenanthrene degradation (43–52%) than did the individual strains. These results provide evidence that Pseudomonas and Pseudarthrobacter can be potential candidates for synergistic phenanthrene degradation at low temperatures. Overall, our study offers valuable information for the bioremediation of PAH contamination in Antarctic environments.

Host factors are associated with vaginal microbiome structure in pregnancy in the ECHO Cohort Consortium

Using pooled vaginal microbiota data from pregnancy cohorts (N = 683 participants) in the Environmental influences on Child Health Outcomes (ECHO) Program, we analyzed 16S rRNA gene amplicon sequences to identify clinical and demographic host factors that associate with vaginal microbiota structure in pregnancy both within and across diverse cohorts. Using PERMANOVA models, we assessed factors associated with vaginal community structure in pregnancy, examined whether host factors were conserved across populations, and tested the independent and combined effects of host factors on vaginal community state types (CSTs) using multinomial logistic regression models. Demographic and social factors explained a larger amount of variation in the vaginal microbiome in pregnancy than clinical factors. After adjustment, lower education, rather than self-identified race, remained a robust predictor of L. iners dominant (CST III) and diverse (CST IV) (OR = 8.44, 95% CI = 4.06–17.6 and OR = 4.18, 95% CI = 1.88–9.26, respectively). In random forest models, we identified specific taxonomic features of host factors, particularly urogenital pathogens associated with pregnancy complications (Aerococcus christensenii and Gardnerella spp.) among other facultative anaerobes and key markers of community instability (L. iners). Sociodemographic factors were robustly associated with vaginal microbiota structure in pregnancy and should be considered as sources of variation in human microbiome studies.

Comparative characterization of supragingival plaque microbiomes in malocclusion adult female patients undergoing orthodontic treatment with removable aligners or fixed appliances: a descriptive cross-sectional study.

This study aimed to explore the effects of removable aligners and fixed appliances on the supragingival bacterial communities in adult female patients undergoing orthodontic treatment. Supragingival plaque samples from 48 female individuals underwent microbiome analysis (16S rRNA gene sequencing) using PacBio Sequel sequencing. The study included 13 adults without orthodontic treatment needs as the control group (Group C), and 35 patients with comparable initial orthodontic conditions who received treatment at a university clinic in Beijing, China. The treatment involved either traditional fixed brackets (Group B, n = 17) or Invisalign® aligners (Group AT, n = 18). Bioinformatics methods were used for data analysis. From the 48 plaque samples, a total of 334,961 valid reads were obtained, averaging 6,978 sequences per sample. The 16S rDNA sequences were classified into 25,727 amplicon sequence variants (ASVs). Significant variances in alpha and beta diversity among the groups were noted. Group B microbiome exhibited an increased presence of Gram-negative bacteria. At the phylum level, Actinobacteriota was significantly more prevalent in Group C samples, while Bacteroidota was enriched in Group B samples. Family-level relative abundance analysis showed a notable increase in Saccharibacteria (formerly TM7) and Prevotellaceae in Group B. Genus-level analysis revealed a significant rise in Lautropia in Group AT. Fixed orthodontic appliances were linked to oral microbiome changes, notably an enhanced relative abundance of anaerobes, including periodontal pathogens. The observation points to the impact of orthodontic appliance on the oral microbial community, highlighting the difference between traditional braces (Group B) and clear aligners (Group AT)in terms of the predominance of anaerobic and gram negative bacteria. This emphasizes the importance of considering the microbiological effects when choosing orthodontic appliance and underscores the need for tailored oral hygiene practices for individuals undergoing these treatments. This research might provide insights that could assist in the development of innovative cleaning techniques and antibacterial materials.

Serratia montpellierensis sp. nov., Isolated from Laboratory-Reared Parasitic Wasps Psyttalia lounsburyii Silvestri and Psyttalia ponerophaga Silvestri (Hymenoptera: Braconidae).

Two strains of bacteria, PsyLou2AT and PsyPon4B, were isolated from adult braconid wasps Psyttalia lounsburyii and Psyttalia ponerophaga, respectively. These laboratory-reared wasps were investigated as agents for biological control of the olive fruit fly, Bactrocera oleae. Analysis of 16S rRNA genes of the two isolates demonstrated that they were highly related and belonged to the genus Serratia. Genomic sequencing of these isolates revealed genomes of 5,152,551bp and 5,154,385bp for PsyLou2AT and PsyPon4B, respectively, and both genomes had a mol% G+C content of 59.6%. Phylogenetic analyses using BLAST-based average nucleotide identity (ANIb), and digital DNA-DNA hybridization methods indicated that PsyLou2AT was most closely related to Serratia nevei S15T, producing ANIb and dDDH values of 96.11% and 70.2%, respectively. Since these values were literally on the species cutoff threshold, additional S. nevei genome assemblies were analyzed using ANIb and dDDH calculations. This revealed that among assemblies that were clearly identifiable as S. nevei, S. nevei S15T was the most closely related to PsyLou2AT, and that a majority of assemblies produced dDDH values of 68.3-68.7% relative to PsyLou2AT. Additionally, PsyLou2AT differed biochemically from S. nevei S15T in that it produced positive Voges Proskauer tests, produced protease, lacked arginine dihydrolase, and did not utilize D-lactose. Hence, PsyLou2AT represents a novel taxon within the Serratia, for which we propose the name Serratia montpellierensis sp. nov. The type strain is PsyLou2AT (=LMG 32817T =NRRL B-65689T).

Methanooceanicella nereidis gen. nov., sp. nov., the first oceanic Methanocellaceae methanogen, isolated from potential methane hydrate bearing area offshore southwestern Taiwan.

A novel mesophilic, hydrogenotrophic methanogen, strain CWC-04T, was obtained from a sediment sample extracted from a gravity core retrieved at station 22 within the KP-9 area off the southwestern coast of Taiwan during the ORIII-1368 cruise in 2009. Cells of strain CWC-04T were rod-shaped, 1.4-2.9 µm long by 0.5-0.6 µm wide, and occurred singly. Strain CWC-04Tutilized formate, H2/CO2, 2-propanol/CO2 or 2-butanol/CO2 as catabolic substrates. The optimal growth conditions were 42 °C, 0.17 M NaCl and pH 5.35. The genomic DNA G+C content calculated from the genome sequence of strain CWC-04T was 46.19 mol%. Phylogenetic analysis of 16S rRNA gene revealed that strain CWC-04T is affiliated with the genus Methanocella. The 16S rRNA gene sequences similarities within strains Methanocella arvoryzae MRE50T, Methanocella paludicola SANAET and Methanocella conradii HZ254T were 93.7, 93.0 and 91.3 %, respectively. In addition, the optical density of CWC-04T culture dropped abruptly upon entering the late-log growth phase, with virus-like particles (150 nm in diameter) being observed on and around the cells. This observation suggests that strain CWC-04T harbours a lytic virus. Based on these phenotypic, phylogenetic and genomic results, we propose that strain CWC-04T represents a novel species of a novel genus in the family Methanocellaceae, for which the name Methanooceanicella nereidis gen. nov., sp. nov. is proposed. The type strain is CWC-04T (=BCRC AR10050T=NBRC 113165T).

Microbiome and mitogenomics of the chigger mite Pentidionis agamae: potential role as an Orientia vector and associations with divergent clades of Wolbachia and Borrelia.

Trombiculid mites are globally distributed, highly diverse arachnids that largely lack molecular resources such as whole mitogenomes for the elucidation of taxonomic relationships. Trombiculid larvae (chiggers) parasitise vertebrates and can transmit bacteria (Orientia spp.) responsible for scrub typhus, a zoonotic febrile illness. Orientia tsutsugamushi causes most cases of scrub typhus and is endemic to the Asia-Pacific Region, where it is transmitted by Leptotrombidium spp. chiggers. However, in Dubai, Candidatus Orientia chuto was isolated from a case of scrub typhus and is also known to circulate among rodents in Saudi Arabia and Kenya, although its vectors remain poorly defined. In addition to Orientia, chiggers are often infected with other potential pathogens or arthropod-specific endosymbionts, but their significance for trombiculid biology and public health is unclear. Ten chigger species were collected from rodents in southwestern Saudi Arabia. Chiggers were pooled according to species and screened for Orientia DNA by PCR. Two species (Microtrombicula muhaylensis and Pentidionis agamae) produced positive results for the htrA gene, although Ca. Orientia chuto DNA was confirmed by Sanger sequencing only in P. agamae. Metagenomic sequencing of three pools of P. agamae provided evidence for two other bacterial associates: a spirochaete and a Wolbachia symbiont. Phylogenetic analysis of 16S rRNA and multi-locus sequence typing genes placed the spirochaete in a clade of micromammal-associated Borrelia spp. that are widely-distributed globally with no known vector. For the Wolbachia symbiont, a genome assembly was obtained that allowed phylogenetic localisation in a novel, divergent clade. Cytochrome c oxidase I (COI) barcodes for Saudi Arabian chiggers enabled comparisons with global chigger diversity, revealing several cases of discordance with classical taxonomy. Complete mitogenome assemblies were obtained for the three P. agamae pools and almost 50 SNPs were identified, despite a common geographic origin. P. agamae was identified as a potential vector of Ca. Orientia chuto on the Arabian Peninsula. The detection of an unusual Borrelia sp. and a divergent Wolbachia symbiont in P. agamae indicated links with chigger microbiomes in other parts of the world, while COI barcoding and mitogenomic analyses greatly extended our understanding of inter- and intraspecific relationships in trombiculid mites.

Description of Corynebacterium hiratae sp. nov. isolated from a human tissue bone a novel member of Corynebacterium Genus.

Corynebacterium spp. are widely disseminated in the environment, and they are part of the skin and mucosal microbiota of animals and humans. Reports of human infections by Corynebacterium spp. have increased considerably in recent years and the appearance of multidrug resistant isolates around the world has drawn attention. To describe a new species of Corynebacterium from human tissue bone is described after being misidentified using available methods. For taxonomic analyses, phylogenetic analysis of 16S rRNA and rpoB genes, in silico DNA-DNA hybridization, average nucleotide and amino acid identity, multilocus sequence analysis, and phylogenetic analysis based on the complete genome were used. Genomic taxonomic analyzes revealed values of in silico DNA-DNA hybridization, average nucleotide and amino acids identity below the values necessary for species characterization between the analyzed isolates and the closest phylogenetic relative Corynebacterium aurimucosum DSM 44532T. Genomic taxonomic analyzes indicate that the isolates analyzed comprise a new species of the Corynebacterium genus, which we propose to name Corynebacterium hiratae sp. nov. with isolate 332T (= CBAS 826T = CCBH 35,014T) as the type strain.

Domestic dogs in indigenous Amazonian communities: Key players in Leptospira cycling and transmission?

Leptospirosis is the world's most common zoonotic disease. Mitigation and control rely on pathogen identification and understanding the roles of potential reservoirs in cycling and transmission. Underreporting and misdiagnosis obscure the magnitude of the problem and confound efforts to understand key epidemiological components. Difficulties in culturing hamper the use of serological diagnostics and delay the development of DNA detection methods. As a result, especially in complex ecosystems, we know very little about the importance of different mammalian host species in cycling and transmission to humans. We sampled dogs from five indigenous Kichwa communities living in the Yasuní National Park in the Ecuadorian Amazon basin. Blood and urine samples from domestic dogs were collected to assess the exposure of these animals to Leptospira and to identify the circulating species. Microscopic Agglutination Tests with a panel of 22 different serovars showed anti-leptospira antibodies in 36 sampled dogs (75%), and 7 serogroups were detected. Two DNA-based detection assays revealed pathogenic Leptospira DNA in 18 of 19 dog urine samples (94.7%). Amplicon sequencing and phylogenetic analysis of 16S rRNA and SecY genes from 15 urine samples revealed genetic diversity within two of three different Leptospira species: noguchii (n = 7), santarosai (n = 7), and interrogans (n = 1). The high prevalence of antibodies and Leptospira DNA provides strong evidence for high rates of past and current infections. Such high prevalence has not been previously reported for dogs. These dogs live in the peridomestic environment in close contact with humans, yet they are free-ranging animals that interact with wildlife. This complex web of interactions may explain the diverse types of pathogenic Leptospira observed in this study. Our results suggest that domestic dogs are likely to play an important role in the cycling and transmission of Leptospira. Future studies in areas with complex ecoepidemiology will enable better parsing of the significance of genotypic, environmental, and host characteristics.