16S rDNA Research Articles

ISOLATION AND CHARACTERIZATION OF BIOFILM FORMING ESCHERICHIA COLI FROM CHICKEN MEAT SAMPLES

The present study was aimed to investigate the presence of Escherichia coli (E.coli) in raw chicken meat samples collected from retail shops, as well as the biofilm-forming ability of field isolates, and to characterize different adhesion genes. Out of 20 chicken meat samples, 17 (85%) were positive for E. coli. Fifteen E. coli strains were characterized by PCR using the 16S rDNA primers and all the isolates were positive which confirmed that all the isolates were E.coli. Out of the 15 confirmed E.coli field isolates which were subjected to biofilm-forming assay, 46% of them were found to be strong biofilm producers. While all the isolates were screened for the presence of adhesion genes viz. luxS, csgA, fimH, fimA, and papC, the adhesion gene luxS was detected in all the strains (100%). The other adhesion genes csgA, fimH and fimA were detected in 93%, 93%, and 73% of the isolates, respectively. The E. coli field isolates were screened blaTEM gene was detected in only four strains, which was categorized under strong biofilm producers. This study demonstrated the presence of biofilm forming E. coli in the raw chicken meat samples as contaminants, causing spoilage and potentially posing risk to consumer’s health and safety.

Damage-associated molecular patterns in bacteraemic infection, including a comparative analysis with bacterial DNA, a pathogen-associated molecular pattern

Damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) are key triggers of inflammation in sepsis. However, they have rarely been studied simultaneously. Thus, in the present study of patients with bacteraemic infection, we aimed to study how DAMP dynamics are linked to disease severity and outcome and to compare diagnostic and prognostic properties of a DAMP and a previously analysed PAMP (16S rDNA). In a prospective study of adult patients hospitalized with culture-proven community-onset bacteraemic infection, caused by Streptococcus pneumonia (n = 30), Staphylococcus aureus (n = 27), or Escherichia coli (n = 26), dynamics of a PAMP, i.e. 16S rDNA, have previously been presented. For the present study, blood samples obtained on hospital days 1–2 (when blood culture was positive), 3–4, 7 ± 1, 14 ± 2, and 28 ± 4 were analysed for four different DAMPs, i.e., nuclear DNA (nDNA), mitochondrial DNA (mtDNA), heat shock protein 90 alpha (HSP90α), and extracellular high mobility group box 1 (HMGB1). Sepsis was defined according to the Sepsis-3 criteria. The study outcomes were sepsis at admission and negative outcome, defined as intensive care unit (ICU) admission and/or death within 60 days. Of 83 study patients, sepsis was noted in 41 patients (49%) and a negative outcome was noted in 17 patients (20%). nDNA had areas under the receiver operating characteristic (ROC) curves of 0.78 for sepsis and 0.76 for negative outcome, which were higher than those of the other DAMPs and additional biomarkers (CRP, IL-6, IL-8, and IL-10). The nDNA and positive 16S rDNA results on day 1–2 were correlated with each other (r = 0.68, p < 0.001). Multivariate analyses showed that high day 1–2 concentrations of both nDNA and 16S rDNA were independently associated with sepsis. In addition, high day 1–2 concentration of nDNA was independently associated with negative outcomes. While 16S rDNA dissipated from the circulation within days, nDNA concentrations remained elevated throughout the follow-up period in patients with negative outcome. In conclusion, nDNA outperformed the other DAMPs regarding sepsis detection and outcome prediction. Both nDNA (a DAMP) and 16S rDNA (a PAMP) were independently linked to sepsis; nDNA was also associated with negative outcomes and persisted elevated in such cases. This highlights nDNA as an interesting marker within sepsis pathogenesis and as a promising clinical biomarker, warranting further studies.

Research on the Mechanism of Root Endophytes of Morus alba L. and Fraxinus mandshurica Rupr., Two Host Plants Growing Inonotus hispidus (Bull.) P. Karst., with Metabarcoding and Metabolomics

Inonotus hispidus (Bull.) P. Karst., is a medicinal fungus, which parasitizes broad-leaved tree such as Morus alba L., Fraxinus mandshurica Rupr., and Ulmus macrocarpa Hance. To elucidate the internal relationship between I. hispidus and its hosts, this study analyzed endophytic bacteria and fungi in the roots of M. alba and F. mandshurica growing I. hispidus using the 16S rDNA and ITS high-throughput sequencing technologies; and conducted widely targeted metabolomics research using UPLC-MS/MS. The results showed that Cyanobacteria and unidentified chloroplasts had the highest relative abundance at the phylum and genus levels, respectively. For endophytic fungi, Ascomycota was dominant at the phylum level, while Pleosporales gen Incertae sedis and Oncopodiella were the dominant genera in the roots of M. alba and F. mandshurica, respectively. Widely targeted metabolomics identified 562 differential metabolites and 46 metabolic pathways. Correlation analysis revealed that Xanthobacteraceae, Pseudorhodoplanes, and Bauldia were potential regulators of phenolic acids and phenylpropanoids biosynthesis. Additionally, the genus Oncopodiella was primarily associated with the enrichment of lipids, amino acids, sugars, phenolic acids, and other compounds. This result provides significant insights into the size of the fruiting body, resource development, and active ingredients of I. hispidus from different tree sources.

High increase of Nichols-like clade circulating Treponema pallidum subsp. pallidum in Barcelona from 2021 to 2023.

Worldwide, more than 90% of contemporary syphilis strains belong to SS14-like clade. This study aimed to describe the molecular profile of circulating Treponema pallidum subsp. pallidum (TPA) strains in Barcelona, Spain, from 2021 to 2023 building upon our report in 2015 which showed that 94.8% of typed strains belonged to the SS14 clade. Multilocus sequence typing (MLST) was conducted on TPA-positive samples obtained from swab samples by sequencing the tp0136, tp0548, and tp0705 loci. Strains were classified as Nichols-like or SS14-like clade. Macrolide and tetracycline resistance‑associated mutations were determined through analysis of 23S rDNA and 16S rRNA gene sequences. Of the 96 typeable samples, 47.9% belonged to SS14-like and 52.1% to the Nichols-like. Fourteen haplotypes were identified, with ST26 representing 43.8% of the samples, distributed across 11 haplotypes in the SS14-like and 3 haplotypes in the Nichols-like. All the samples showed macrolide resistance-associated mutations, while none exhibited tetracycline-associated mutations. Our findings revealed a substantial shift in the proportion of TPA clades within the Barcelona population from 2021 to 2023, characterized by a higher proportion of Nichols-like strains compared to 2015 and international trends. The varying temporal and geographical trends underscore the need for regular surveillance to understand regional variations in syphilis and strengthen control programs.

First isolation of Campylobacter vicugnae sp. nov. in humans suffering from gastroenteritis.

The present study describes the first isolation of a recently described Campylobacter species, Campylobacter vicugnae, in humans. The isolates were recovered by two independent French laboratories in 2020 and 2022 from a man and a woman suffering from gastroenteritis. Biochemical and growth characteristics, and electron microscopy for these two strains indicated that they belong to Campylobacter genus. 16S rDNA and GyrA-based phylogeny, as well as average nucleotide identity and in silico DNA-DNA Hybridization analyses revealed that both strains belong to the Campylobacter vicugnae species. Both isolates possess a complete cytolethal distending toxin (CDT) locus with cdtA, cdtB, and cdtC, and features of CDT activity were demonstrated in vitro with Caco-2 intestinal epithelial cells. Our data suggest that these two isolates of C. vicugnae were associated with gastroenteritis in humans and induced major cytopathogenic effects in vitro. C. vicugnae is likely to be a novel human pathogen, with a source of foodborne infection that needs to be determined.IMPORTANCECampylobacter species that display toxicity features are a worldwide public health issue. In clinical contexts, it is crucial to identify which isolate could be an urgent threat to a patient. Actual and widely used laboratory methods such as mass spectrometry or PCR may be flawed in the field of species identification. In contrast, the present study shows that next-generation sequencing allows to precisely identify isolates to species level that may have been omitted otherwise. Moreover, it helps to identify emerging species before they become a threat to human health. Recovery of a new Campylobacter species in human sample, such as the new species "Campylobacter vicugnae," is an important step for the identification of emerging pathogens posing threat to global health.

Study on effect of plant growth promoting rhizobacteria on sorghum (Sorghum bicolor L.) under gnotobiotic conditions.

The rhizosphere is enriched with diverse microflora, allowing for delving prospective microorganisms to enhance crop growth and yield for varied soil conditions. Demand for millet growth-promoting microorganisms is a contemporary need for dryland agriculture. Therefore, a detailed survey was conducted in northern Karnataka, India, to identify the millet growing areas, particularly sorghum. The rhizobacteria from the sorghum (Sorghum bicolor L.) were assessed for promoting seed germination using the paper towel method and classified based on their efficiency. The elite isolates were positive for indole-3-acetic acid (IAA), gibberellic acid (GA), phosphate, zinc oxide solubilization, and hydrogen cyanide (HCN) production. The test isolates were antagonistic to Macrophomina phaseolina and Fusarium sp. and inhibited completely. Further evaluation of the cultures on sorghum growth-promoting attributes under pot culture conditions showed that the plants inoculated with PG-152 (Bacillus subtilis) recorded the highest plant height, chlorophyll content, root dry weight, shoot dry weight, and total dry weight under ideal conditions of fertilization. Two isolates, namely, PG-152 and PG-197, performing superior under pot culture conditions, were identified as Bacillus subtilis and PG-197 as Enterobacter sp., respectively, using 16S rDNA analysis. The sequences were allowed to screen open reading frames (ORF) and found several ORFs in Enterobacter cloacae and Bacillus subtilis, respectively. This study found that the rhizosphere is vital for identifying prospective isolates for biocontrol and plant growth-improving microorganisms.

Rifaximin alleviates MCD diet-induced NASH in mice by restoring the gut microbiota and intestinal barrier

AimsDue to the increasing global incidence rate of nonalcoholic steatohepatitis (NASH) combined with the lack of effective treatment methods for this disease, there is an urgent need to find new treatment strategies. The aim of this study was to investigate the efficacy of rifaximin in preventing and treating NASH and the related mechanism. Materials and methodsA NASH model was constructed by feeding male C57BL/6 mice a methionine-choline-deficient (MCD) diet for 4 weeks. Rifaximin was administered for 1 week before MCD diet feeding or during the last week of MCD diet feeding to investigate its preventive or therapeutic effects. Liver pathology, hepatic enzyme levels and metabolic indices were measured to evaluate the effects of rifaximin on NASH. Intestinal barrier integrity was measured via the Ussing chamber system and western blotting. 16S rDNA sequencing was conducted to investigate the fecal microbiota composition. Western blotting was performed to evaluate peroxisome proliferator activated receptor (PPAR)α and PPARγ protein levels. Key findingsRifaximin effectively alleviated MCD diet-induced NASH. The microbiota composition in MCD diet-fed mice was significantly altered, and intestinal barrier integrity was disrupted. Dysbiosis and intestinal barrier dysfunction were reversed by rifaximin. In addition, rifaximin modulated PPARα and PPARγ expression in the liver. SignificanceRifaximin effectively alleviated MCD diet-induced NASH by restoring the gut microbiota and reversing intestinal barrier dysfunction, suggesting that rifaximin treatment is a new approach for preventing and treating NASH.

Description of a new Ornithodoros (Pavlovskyella) (Ixodida: Argasidae) tick species from Pakistan.

The genus Ornithodoros is notably diverse within the family Argasidae, comprising approximately 134 species distributed among 4 subgenera, 1 of which is the subgenus Pavlovskyella. In an earlier study, we identified distinct soft ticks as Ornithodoros (Pavlovskyella) sp., which were collected from animal shelters in Khyber Pakhtunkhwa, Pakistan. Providing additional collections from that same locality and a comprehensive analysis involving detailed morphological and mitogenome-based comparisons with closely related species, this study formally designates a novel species for these specimens. Adults and late-instar nymphs of the new species display a dorsoventral groove, small cheeks not covering the capitulum, 5 small even humps on tarsus I and a transverse postanal groove intersecting the median postanal groove perpendicularly. It also lacks a tuft of setae on the ventral surface of the hood which separates the novel species from Ornithodoros papillipes. Ventral chaetotaxy of tarsus IV indicates 4–7 setal pairs in nymphs and 5–7 pairs in adults that separate the new species from Ornithodoros tholozani sensu stricto and Ornithodoros crossi, 2 morphologically closely related species that occur in geographical proximity. Phylogenetic analyses of the full-length mitochondrial genome and the 18S and 28S ribosomal RNA genes, combined with pairwise nucleotide comparisons of cox1, cox2, atp8, atp6, cox3, nad3, nad5, nad4, nad4L, nad6, cytb, nad1, nad2, 12S rDNA, 16S rDNA, 18S rDNA and 28S rDNA further support that the new species belongs to the Pavlovskyella subgenus, clustering with O. tholozani, Ornithodoros verrucosus and Ornithodoros tartakovskyi.

Dihydromyricetin ameliorate postmenopausal osteoporosis in ovariectomized mice: Integrative microbiomic and metabolomic analysis.

The gut microbiota may help mitigate bone loss linked to postmenopausal osteoporosis by affecting the immune and inflammatory responses and the gut-bone axis. Dihydromyricetin (DMY), a natural flavonoid, has some anti-inflammatory and antioxidant properties. This study aimed to investigate the mechanisms underlying the amelioration of bone loss in ovariectomized (OVX) mice treated with various doses of DMY. Eight-week-old C57/BL6 mice underwent ovariectomy and received varying DMY doses over 8 weeks. Thereafter, femoral bone microarchitecture, serum biomarker levels, and colon samples were analyzed to assess bone metabolism and inflammatory and hormonal responses. Fecal samples were subjected to 16S rDNA sequencing, and short-chain fatty acids were quantified. An untargeted metabolomics approach was applied to both serum and fecal samples to investigate alterations in the intestinal microbiota and metabolic profiles following DMY treatment in the OVX mice. The results show high-dose DMY has anti-osteoporotic effects. Compared to the OVX group, the DMY-treated group showed enhanced bone mineral density and reduced inflammation and colonic damage levels. The DMY treatment altered the gut microbiota composition, including the relative abundances at both the phylum and genus levels. In addition, DMY treatment increased the production of acetate and propionate. Metabolomic analysis revealed differential regulation of 37 and 70 metabolites in the serum and feces samples, respectively, in the DMY-treated group compared to those in the OVX group, affecting the serotonergic signaling, arachidonic acid metabolism, and unsaturated fatty acid biosynthesis pathways. In conclusion, these findings indicate that DMY can ameliorate bone loss in OVX mice via the gut-bone axis.

Chromosomal mapping of 5S rDNA in two species of the genus Acanthocephalus (Echinorhynchida)

Chromosomal mapping of 5S rDNA in two Acanthocephala species was performed for the first time using fluorescence in situ hybridization (FISH) with a 5S rDNA probe. The 5S rDNA PCR products from the genomes of both species were sequenced and aligned and an identical 141 bp long coding region was determined. The same patterns of 5S rDNA gene cluster distribution were observed, with FISH signal restricted to a single autosomal chromosome pair. A preference for distal positioning on the chromosomes (subtelomeric position) was observed in both species. In addition, two-color FISH was performed to examine the mutual positions of 5S and 18S rDNA on the chromosomes. Our knowledge of the organization of the Acanthocephala genome is extremely limited and its chromosomes are poorly studied. Any new information about the location of chromosomal markers as important features of the respective karyotype may be useful in solving evolutionary questions.

Integrating fecal metabolomics and gut microbiome to reveal the mechanism of Schisandra chinensis-Acorus tatarinowii Schott treatment in Alzheimer’s disease rats

BackgroundSchisandra chinensis (Turcz.) Baill (Schisandraceae) and Acorus tatarinowii Schott (Araceae Juss) (Sc-At) are two traditional Chinese medicinal herbs that are widely used in the treatment of neurological disorders such as insomnia. In our previous study, we found that Sc-At could improve the therapeutic efficacy of Alzheimer’s disease by affecting aromatase activity and estrogen levels, among other pathways. Material and methodsIn this study, first, the ameliorative effect of Sc-At on cognitive dysfunction in Alzheimer’s disease model rats was verified by Y-maze test together with Elisa assay. Second, fecal untargeted metabolomics analysis was performed using a UPLC-Q-TOF/MS-based metabolomics approach. 16S rDNA sequencing was utilized to screen the differential flora between groups, and linear discriminantan alysis effect size (LEfSe) was used to find the target flora. Finally, Spearman correlation analysis was combined to find the relationship between differential flora and differential metabolites in feces. Results(1) The results of Y-maze test and Elisa assay indicated that Sc-At could improve the cognitive dysfunction of AD model rats. (2) Metabolomics results showed that fecal metabolite levels were significantly different from those of rats in the blank group, and 18 potential biomarkers in feces were screened, mainly affecting linoleic acid metabolism, steroid hormone biosynthesis, sphingomyelin metabolism, riboflavin metabolism, etc. The 16S rDNA results showed that the abundance and diversity of intestinal flora in AD rats were destroyed, and the Sc-At treatment was able to reverse these changes. (3) Spearman’s correlation analysis showed a significant correlation between differential metabolites in feces and intestinal flora, further suggesting that Sc-At treats Alzheimer’s disease through the gut-brain axis. ConclusionsIn this study, we explored the mechanism of Sc-At in the treatment of Alzheimer’s disease by integrating fecal untargeted metabolomics and 16S rDNA gene sequencing, and the results showed that Sc-At exerts therapeutic effects on Alzheimer’s disease by improving the intestinal flora and related metabolic pathways.

Effect of exclusive enteral nutrition on gut microbiota in Malaysian children with Crohn’s disease

Abstract Paediatric Crohn’s disease (pCD), once primarily observed in Western countries, is now experiencing a global increase in incidence rates. Southeast Asian nations, including Malaysia, are now witnessing a gradual increase in incidence of pCD. In addition to clinical symptoms, children with Crohn’s disease (CD) also have mental and emotional impairments. Children with CD experience gut microbiota dysbiosis. Exclusive enteral nutrition (EEN) is the recommended first line treatment for mild-to-moderate pCD due to its multifaceted disease-modulating effects, including positive re-modulation of the diseased gut microbiota. However, there exists a critical knowledge gap regarding the understanding of gut microbiota dynamics in individuals with CD treated with EEN, particularly in Southeast Asian regions like Malaysia. This study aimed to fill this void by investigating the gut microbiota profile of Malaysian children with CD, making it the first of its kind in Malaysia. Using targeted 16S ribosomal DNA (16S rDNA) next-generation sequencing, the study identified a microbiota profile dominated by Fusobacterium nucleatum, Haemophilus parainfluenzae, Fusobacterium mortiferum, Acidaminococcus, and Monoglobus among patients with pCD, with the latter three being newly identified in relation to pCD. Following successful EEN treatment, enrichment was observed in bacterial groups such as Lachnoclostridium, Parabacteroides, and Eubacterium fissicatena group. The groups of Clostridium sensu stricto 13 subterminale, Acetivibrio ethanolgignens group, and Robinsoniella peoriensis, which have not been previously associated with pCD, were also found to be increased following EEN treatment. While some similarities with previous literature were noted, Malaysians with pCD treated with EEN exhibited several novel bacterial groups associated both during disease and treatment. This study sheds light on the interplay between gut microbiota and pCD pathology, emphasising the versatility of nutritional therapy approaches in diverse populations. Further research in this area holds promise for refining treatment strategies and improving outcomes for pCD individuals, not only in Malaysia but globally.

Auricularia auricula polysaccharide alleviates cyclophosphamide-induced liver injury in mice involving remodeling of the gut bacteriome, mycobiome, and metabolome

In this study, a novel polysaccharide (AHP) from Auricularia auricula was isolated and purified, showing protective effects against CTX-induced liver injury in mice. To study the action mechanism of AHP, a liver injury model was established by intraperitoneally injection 80 mg/kg of CTX for 3 consecutive days. The focus was on how AHP regulated the gut bacteriome and mycobiome to help alleviate metabolic disorders associated with liver injury. Results showed that AHP amended liver injury by improving liver function, stabilizing oxidative stress homeostasis, reducing inflammatory invasion and activating Akt/GSK3β/Nrf-2/HO-1 signaling pathway. The 16S ribosomal DNA (16S rDNA) and Internal Transcribed Spacer-1 (ITS1) sequencing results demonstrated that AHP supplementation significantly restored the gut bacteriome and mycobiome composition in CTX-induced liver injury mice, by enriching the abundance of beneficial bacteriome (unclassified_Muribaculaceae, Faecalibaculum and Alloprevotella) and mycobiome (Fusarium), reducing the abundance of harmful bacteriome (Akkermanisa) and mycobiome (Fusicolla and Cladosporium). Analysis of untargeted metabolomics indicated that AHP altered the levels of metabolites associated with both bile acid and arachidonic acid metabolism, showing a significant connection to the AHP-regulated bacteriome and mycobiome. To conclude, the findings suggested that AHP was a viable and secure candidate for use as a hepatoprotective medication.

The gut microbiotas with metabolites regulate the protective role of miR-30a-5p in myocardial infarction

IntroductionGut microbial homeostasis is closely associated with myocardial infarction (MI). However, little is known about how gut microbiota influences miRNAs-regulated MI. ObjectivesThis study aims to elucidate the connections between miR-30a-5p, MI, gut microbiota, and gut microbial metabolite-related pathways, to explore potential strategy for preventing and treating MI. MethodsWe evaluated the effects of knocking out (KO) or overexpressing (OE) miR-30a-5p on MI by assessing cardiac structure and function, myocardial enzyme levels, and apoptosis. Then, we applied 16S rDNA sequencing and metabolomics to explore how intestinal microecology and its microorganisms affect miR-30a-5p-regulated MI. ResultsThe results showed that KO exacerbated MI, whereas OE improved MI damage, compared to the wild-type (WT) mice. KO exacerbated intestinal barrier structure deterioration and further downregulated the expression of Cloudin-1, Occludin, and ZO-1 in MI mice. 16S rDNA sequencing-analyzed gut microbiome of KO and WT mice found that KO mainly reduced g_Lactobacillus. Transplanting fecal microorganisms from KO mice aggravated MI damage in WT mice. However, administering probiotics (mainly containing Lactobacillus) helped neutralize these damages. Intriguingly, fecal microbiota transplantation from OE mice reduced MI damage. Analysis of intestinal microbial metabolites in KO and WT mice found that KO may mainly affect ABC transporters. ABCC1 was identified as the target of KO-aggravated MI. Furthermore, fecal transplantation microorganisms of MI patients aggravated MI injury in mice and miR-30a-5p and ABCC1 were involved in the process. ConclusionsOur findings demonstrate that miR-30a-5p regulates MI by affecting intestinal microbiota homeostasis and targeting ABCC1. This highlights the critical importance of maintaining a healthy gut microbiota homeostasis in MI management.

Unambiguous chromosome identification reveals the factors impacting irregular chromosome behaviors in allotriploid AAC Brassica.

The major irregular chromosome pairing and mis-segregation were detected during meiosis through unambiguous chromosome identification and found that allotriploid Brassica can undergo meiosis successfully and produce mostly viable aneuploid gametes. Triploids have played a crucial role in the evolution of species by forming polyploids and facilitating interploidy gene transfer. It is widely accepted that triploids cannot undergo meiosis normally and predominantly produce nonfunctional aneuploid gametes, which restricts their role in species evolution. In this study, we demonstrated that natural and synthetic allotriploid Brassica (AAC), produced by crossing natural and synthetic Brassica napus (AACC) with Brassica rapa (AA), exhibits basically normal chromosome pairing and segregation during meiosis. Homologous A chromosomes paired faithfully and generally segregated equally. Monosomic C chromosomes were largely retained as univalents and randomly entered daughter cells. The primary irregular meiotic behaviors included associations of homoeologs and 45S rDNA loci at diakinesis, as well as homoeologous chromosome replacement and premature sister chromatid separation at anaphase I. Preexisting homoeologous arrangements altered meiotic behaviors in both chromosome irregular pairing and mis-segregation by increasing the formation of A-genomic univalents and A-C bivalents, as well as premature sister chromatid separation and homologous chromosome nondisjunction. Meiotic behaviors depended significantly on the genetic background and heterozygous homoeologous rearrangement. AAC triploids mainly generated aneuploid gametes, most of which were viable. These results demonstrate that allotriploid Brassica containing an intact karyotype can proceed through meiosis successfully, broadening our current understanding of the inheritance and role in species evolution of allotriploid.

A NEW SPECIES OF ACANTHOBOTHRIUM (CESTODA: ONCHOPROTEOCEPHALIDEA), PARASITE OF THE GIANT ELECTRIC RAY NARCINE ENTEMEDOR JORDAN AND STARKS, 1895 (BATOIDEA: TORPEDINIFORMES) FROM MEXICO.

Spiral valves from specimens of the giant electric ray Narcine entemedor Jordan & Starks, 1895 were examined in search of tapeworms at 2 localities of the Mexican tropical Pacific Ocean. Acanthobothrium oceguerai n. sp. is described herein based on material from Ventanilla, Oaxaca and from Acapulco Bay, Guerrero. The new species is a category 6 species, distinguished by being apolytic, retaining proglottids on the strobila until they are gravid, having strobila of 166-322 proglottids, having a small scolex and very long bothridia relative to the scolex, and having abaxial prongs that are short and thin in comparison to the axial prongs, which are longer and more robust. Acanthobothrium oceguerai n. sp. can be differentiated from other members of category 6 by the hooks, which are shorter, more robust, and smaller than those of the other members of this category. The phylogenetic analysis based on the 28S rRNA locus placed Acanthobothrium oceguerai n. sp. as sister to an unidentified species of larval Acanthobothrium from Philadelphia, Pennsylvania. In addition, sequences of the mitochondrial cytochrome oxidase subunit I gene and nuclear 18S rDNA were generated to provide support for future taxon sampling. Acanthobothrium oceguerai n. sp. is the fifth species of cestode reported from N. entemedor in the tropical eastern Pacific.

A new species of the Trichia botrytis complex from the cloud forest in Ecuador

The paper describes a new myxomycete species, Trichia tuberculata, from the Ecuadorian cloud forest. The phylogeny constructed with nuclear 18S rDNA and mitochondrial 17S rDNA sequences indicates that the taxon is closely related to the recently described species T. acetocorticola, T. nubila, and T. pinicola, all within the T. botrytis complex. The morphology of the inner peridium surface and capillitium also aligns T. tuberculata with these species. However, the distinctive tuberculate peridium, short elater tips, and perhaps the distribution range (so far found in the equatorial zone only) distinguish T. tuberculata from related taxa.

Identification and characterisation of dextran produced by a novel high yielding Weissella cibaria Fiplydextran strain

An exopolysaccharide (EPS)-producing bacterial strain was isolated from fermented soy milk and identified as Weissella cibaria strain Fiplydextran through morphological, biochemical and 16S rDNA sequence analysis. Here, we report the optimisation of cultural conditions for the organism to achieve maximum EPS production, along with its molecular characterisation, functional properties, and prebiotic potential. The exceptionally high EPS yield (0.61 g per g of sucrose) was obtained from the optimised medium (200 g/L of sucrose, 15 g/L of yeast extract) at 30 °C after 48 h. HPAEC-PAD analysis revealed that the EPS is homopolymer of glucose having Mw as 3.23 × 107 Da determined using viscosity method. Methylation analysis and NMR results confirmed the EPS as dextran with α (1 → 6)-linkage (96.5 %) as main chain and α (1 → 3)- as branch chain linkage (3.5 %). Thermogravimetric analysis exhibited higher thermal stability of EPS. The EPS was observed to support the growth of Bacteroides spp. in pure culture form but not that of Lactobacillus or Bifidobacterium spp. However, a low level of bifidogenic activity was observed upon use of mixed culture of B. fragilis and B. longum. The research implies industrial applications of W. cibaria Fiplydextran for the production of high molecular weight dextran with better yield.

Disordered Gut Microbiome and Alterations in Metabolic Patterns Are Associated With Hypertensive Left Ventricular Hypertrophy.

Left ventricular hypertrophy (LVH) is most common when driven by hypertension, and it is a strong independent risk factor for adverse cardiovascular events and death. Some animal models support a role for gut microbiota and metabolites in the development of LVH, but cohort studies confirming these findings in populations are lacking. We investigated the alterations of gut microbiota and metabolites in 30 patients with hypertension, 30 patients with hypertensive LVH, and 30 matched controls on the basis of 16S rDNA and metabolomic analyses. Thirty stool and 90 serum samples were collected in fasting conditions. ANOVA/Kruskal-Wallis/Pearson's χ2/Fisher's exact test and Bonferroni's correction were used (P<0.0167) for comparison among the 3 groups. A regression analysis and subgroup analysis were performed between gut microbiota and left ventricular mass index (LVMI) and metabolites and LVMI, respectively. Spearman correlation analysis was performed between metabolites and flora and metabolites and LVMI. We observed LVH-enriched Faecalitalea (β=6758.55 [95% CI, 2080.92-11436.18]; P=0.009), Turicibacter (β=8424.76 [95% CI, 2494.05-14355.47]; P=0.01), Ruminococcus torques group (β=840.88 [95% CI, 223.1-1458.67]; P=0.013), and Erysipelotrichaceae UCG-003 (β=856.37 [95% CI, 182.76-1529.98]; P=0.019) were positively correlated with LVMI. A total of 1141 (in sera) and 2657 (in feces) metabolites were identified. There was a sex-specific association between metabolites and LVMI. Significant changes in metabolic pathways in LVH were also observed, especially bile acid and lipid metabolism pathways. Our study demonstrated the disordered gut microbiota and microbial metabolite profiles in LVH. This highlights the roles of gut bacteria and metabolite in this disease and could lead to new intervention, diagnostic, or management paradigms for LVH. URL: https://www.chictr.org.cn; Unique Identifier: ChiCTR2200055603.

Comparative analysis of intestinal structure, enzyme activity, intestinal microbiota and gene expression in different segments of pufferfish (Takifugu Obscurus)

The structure of fish intestines does not have a clear regional division, while the function of the intestines may be related to their structure. Therefore, in this study, the delimitation of intestinal segments in pufferfish (Takifugu obscurus) was achieved by morphological analysis. Subsequently, enzyme activity, intestinal microbiota, and gene expression were examined to compare the differences among the pufferfish various segments. According to four morphological parameters: height of mucosa folds (HF), width of mucosa folds (WF), thickness of muscularis (TM), and cross-sectional area (CSA), the pufferfish's intestine was divided into anterior intestine (AI), middle intestine (MI), and posterior intestine (PI). The activity levels of amylase, lipase, and trypsin in the AI and MI were significantly higher than these in the PI. According to the analysis of 16S rDNA, the dominant microbiota at the phylum level in the different segments were Epsilonbacteraeota, Spirochaetes, and Proteobacteria. At the genus level, there were variations observed in the relative abundance of Brevinema, Mycobacterium, Bradyrhizobium, and Microvirga. α diversity analysis revealed that the richness indexes (Ace and Chao1) were the lowest in the MI, while β diversity analysis revealed significant difference in intestinal microbial community composition among the three intestinal segments. Furthermore, RNA-Seq was used to identify differential expression genes (DEGs) and biological pathways among the different intestinal segments. The DEGs between the AI and MI were enriched in pancreatic secretion and protein digestion and absorption, those between AI and PI were involved in ascorbate and aldarate metabolism and glutathione metabolism, and those between MI and PI were involved in steroid biosynthesis, fat digestion and absorption, vitamin digestion and absorption, and glycine, serine and threonine metabolism. In conclusion, the presented results compare and analyze the differences in various intestinal segments of pufferfish, which will be conductive to future exploration of the functions of these different segments.