rDNA Gene Research Articles

Morphological and Molecular Analyses of Aponurus laguncula Looss, 1907 (Digenea: Lecithasteridae) Parasitic in Atlantic Spadefish Chaetodipterus faber (Broussonet, 1782) (Acanthuriformes: Ephippidae) from Brazilian Coastal Zone.

An integrative taxonomic description of Aponurus laguncula (Lecithasteridae), a digenean parasitic species of Chaetodipterus faber (Acanthuriformes) from Brazilian Southeast, is provided. Morphological techniques, as whole mounted slides, histology and scanning electron microscopy, and molecular analyses supported that integrative description. Fifteen digenean specimens were stained in hydrochloric carmine and mounted on permanent slides. Two specimens were stained in hematoxylin and eosin following histological routine processing. Four parasites were dehydrated through a graded ethanol series, critical point dried with carbon dioxide and coated with gold to scanning electron microscopy analysis. Sequence of the large ribosomal subunit (28S rDNA) gene was generated and used to construct a phylogeny based on maximum likelihood and Bayesian inference analyses. Morphological description and morphometric data obtained in present study were in accordance with previous studies of the species. Use of another morphological techniques, as scanning electron microscopy and histology, corroborated the observed features of whole mounted slides. Also, they provided a better observation of previous reported characteristics and new features reporting, such as an elongated hermaphroditic duct, a smooth tegument and cells that compose the prostatic gland. The molecular sequence obtained in the present study formed a robust clade with available sequences of species of Aponurus. The integrative taxonomic approach successfully combined morphological observations, including both previously reported features and new descriptions from histological and electron microscopy analyses, with molecular data to identify these specimens as A. laguncula. Moreover, the detailed characterization of structures, such as the gonads in A. laguncula, that would be challenging to analyze using a single technique, was possible. Further molecular studies with less conserved genetic markers should be conducted to understand phylogenetic relationships between Aponurus species.

Modifications in the Composition of the Gut Microbiota in Rats Induced by Chronic Sleep Deprivation: Potential Relation to Mental Disorders.

Sleep deprivation(SD) has numerous negative effects on mental health. A growing body of research has confirmed the implication of gut microbiota in mental disorders. However, the specific modifications in mammalian gut microbiota following SD exhibit variations across different studies. Male specific-pathogen-free Wistar rats were given a modified multiple-platform exposure for 7 days of SD. Fecal samples were obtained from the control and SD groups both at baseline and after 7 days of SD. We utilized 16S rDNA gene sequencing to investigate the gut microbial composition and functional pathways in rats. Analysis of the microbiota composition revealed a significant change in gut microbial composition after chronic SD, especially at the phylum level. The relative abundances of p_Firmicutes, g_Romboutsia, and g_Enterococcus increased, whereas those of p_Bacteroidetes, p_Verrucomicrobia, p_Fusobacteria, g_Akkermansia, and g_Cetobacterium decreased in animals after chronic SD compared with controls or animals before SD. The ratio of Firmicutes to Bacteroidetes exhibited an increase following SD. The relative abundance of gut microbiota related to the functional pathways of GABAergic and glutamatergic synapses was observed to be diminished in rats following SD compared to pre-SD. Collectively, these findings suggest that chronic SD causes significant alterations in both the structural composition and functional pathways of the gut microbiome. Further researches are necessary to investigate the chronological and causal connections among SD, the gut microbiota and mental disorders.

Development and evaluation of a TaqMan® real-time PCR assay for species-specific detection of Ehrlichia canis

The aim of this work was to develop a real-time PCR assay with a TaqMan® probe that detects a species-specific part of the 16S rDNA gene of Ehrlichia canis. Canine blood samples (n = 207), collected and tested by a conventional PCR assay within a study conducted by De Salvo et al., were simultaneously analyzed with the novel designed real-time PCR, and the results of both assays were compared. The agreement between the two methods was 97.6 % with a kappa value of 0.92186. Hereby, the standard error was 0.034416 and the 95 % confidence interval from 0.8544 to 0.98931. While the conventional PCR assay showed false negative results (2.42 %; 5/207), the real-time PCR assays showed a specificity of 100 %. The results of the current study showed that the developed assay presents sensitivity and specificity for the detection of E. canis in blood samples, adding a new tool for the diagnosis of this pathogen.

A New Species of Creptotrematina (Trematoda: Allocreadiidae) from the Red Minor Tetra, Hyphessobrycon eques (Steindachner, 1882) (Characidae) from Brazil, with Comments on the Genetic Divergence of C. Aguirrepequenoi Jiménez-Guzmán, 1973 across a Wide Geographical Range in Middle America.

Allocreadiids are relatively small digeneans that appear to be restricted to freshwater systems distributed across the world. Allocreadiids are highly diverse in the Americas, particularly in the Neotropical biogeographical region. Their taxonomic history has been rather controversial, with several taxonomic reassessments and the description of new genera and species. We sampled Creptotrematina specimens from a characid collected in the Pardo River, Paranapanema River basin in Brazil, and specimens of C. aguirrepequenoi, from Astyanax spp. in several localities between northern Mexico and Costa Rica. The specimens were studied through integrative approaches using morphological and molecular analyses of the 28S rDNA gene and two different regions of the COI mtDNA gene. We describe a new species of Creptotrematina which is differentiated from other congeners by the overall body size, but in particular by the size and position of the cirrus-sac, distribution of the vitelline follicles, and extension of uterine loops in the posterior end of body. Phylogenetic analyses of the 28S rDNA and COI mtDNA genes placed the new species in a monophyletic clade together with all other sequenced species of Creptotrematina, and as a sister species of C. batalhensis. Genetic divergences between the new species and other Creptotrematina spp. varied from 1.1 to 1.2% for the 28S rDNA and 12.4-14.3% for the COI mtDNA. Phylogenetic analysis based on COI mtDNA showed the isolates of C. aguirrepequenoi grouped in four monophyletic clades representing populations geographically separated along a wide geographical range spanning between northern Mexico and Costa Rica, with an estimated genetic divergence between 3.9% and 8.9%. Our findings based on integrative analyses recognize Creptotrematina saltograndensis n. sp. from a characid collected in the Pardo River, Paranapanema River basin in Brazil and provide validation of the wide geographical distribution of C. aguirrepequenoi across Middle-America parasitizing Astyanax spp.; the genetic divergence of the species through the analysis of two regions of COI mtDNA points towards considering it represent a species complex, although we refrain at the moment on describing a new species, awaiting for further verification using other molecular markers, and obtaining fresh material for a more detailed taxonomic analyses. This study increases the known diversity of allocreadiids and contributes to the understanding of evolutionary relationships, host-parasite relationships, and biogeographic history of the group.

Strong Activation of ID1, ID2, and ID3 Genes Is Coupled with the Formation of Vasculogenic Mimicry Phenotype in Melanoma Cells.

Gene expression patterns are very sensitive to external influences and are reflected in phenotypic changes. It was previously described that transferring melanoma cells from a plastic surface to Matrigel led to formation of de novo vascular networks-vasculogenic mimicry-that are characteristic to a stemness phenotype in aggressive tumors. Up to now there was no detailed data about the gene signature accompanying this process. Here, we show that this transfer shortly led to extremely strong epigenetic changes in gene expression in the melanoma cells. We observed that on Matrigel numerous genes controlling ribosome biogenesis were upregulated. However, most of the activated genes were inhibitors of the differentiation genes (ID1, ID2, and ID3). At the same time, the genes that control differentiation were downregulated. Both the upregulated and the downregulated genes are simultaneously targeted by different transcription factors shaping sets of co-expressed genes. The specific group of downregulated genes shaping contacts with rDNA genes are also associated with the H3K27me3 mark and with numerous lincRNAs and miRNAs. We conclude that the stemness phenotype of melanoma cells is due to the downregulation of developmental genes and formation of dedifferentiated cells.

Genetic Differentiation Between Sympatric Crustacean Decapods Inhabiting the Mediterranean Sea: Implications to Avoid Larval and Adult Misidentification

ABSTRACTThe conservation of species, especially those with high levels of exploitation and economic interest, relies on the knowledge of their biology and geographical distribution. In the marine realm, similar morphology between species is a common difficulty in identifying sympatric species, especially in early stages of development. Therefore, genetic identification of crustacean species has been shown to be the only way to identify the species. We used a 451‐bp fragment of the 16S rDNA gene to differentiate nine species of decapod crustaceans, five of which are sympatric and heavily exploited in the Mediterranean Sea: Aristeus antennatus (blue and red shrimp), A. virilis (stout red shrimp), A. varidens (striped red shrimp), Aristaeomorpha foliacea (giant red shrimp), Aristaeopsis edwardsiana (scarlet shrimp), Gennadas elegans (graceful blunt‐tail prawn), Gennadas valens (valuable blunt‐tail prawn), Parapenaeus longirostris (deep‐water rose shrimp) and Penaeus kerathurus (camarote prawn). Analysis of the 16S rDNA gene provides clear evidence of genetic differentiation to be used as an easy method to identify these species.

PCR identification of Enterococcus Species as a Primary Pathogen in Neonatal Bloodstream Infections at Damascus University Paediatric Hospital

Bacterial septicaemia is one of the most common causes of death in newborns throughout the globe. Recently, gram positive bacteria have been detected as a main responsible of hospital acquired blood infection in developed country especially Enterococcus sp. and Staphylococcus sp. This preliminary study aimed to identify Enterococcus species and Staphylococcus species isolated form acquired blood infection in the department of premature and neonates at paediatric university hospital in Damascus, based on PCR technology. the antibiotic sensitivity these pathogens was also investigated against common antibiotics usually used to treat septicaemia in this hospital. Bacterial gDNA was extracted directly from blood samples of children with acquired Septicemia. The bacterial infection was confirmed in 50 samples based on the amplification of 16srDNA gene. Genus Enterococcus sp. and Staphylococcus species were identified as source of infection in samples using specific primers via PCR technique. The antibiotic sensitivity of isolated bacterial strains was studied using Kirby-Bauer disc method. Our study showed that 47 of the 50 samples of the infection were bacterial. The rate of blood infection caused by Enterococcus species was 24%, and 4% for Staphylococcus sp. the isolated bacteria showed a high sensitivity to Amikacin, medium sensitivity to Vancomycin, and less sensitivity to Ampicillin and Gentamycin. Enterococcus species Showed good sensitivity to Amikacin and Vancomycin and low sensitivity to Gentamycin, while was resistant to Ampicillin. Furthermore, the two isolated stains Enterococcus sp and Staphylococcus species showed a good sensitivity against chlorhexidine. This study confirmed the importance of molecular technologies in diagnosing the acquired septicaemia and identifying the specific infectious agent. The molecular test showed that Enterococcus sp. was an important cause of acquired blood infection in neonates respect to ampicillin resistant staphylococcus species.

Unraveling microbial community variation along a salinity gradient and indicative significance to groundwater salinization in the coastal aquifer

Saltwater intrusion poses a global environmental challenge in coastal regions, profoundly influencing groundwater microbial communities and biogeochemical processes. This study aims to elucidate the origin of groundwater salinity and understand the response of microbial interactions to groundwater salination through stable isotopes and 16S rDNA gene sequencing. The findings reveal a significant increase in groundwater TDS from inland to the coastline, ranging from 0.5 g/L to 144.6 g/L. Ionic relationship and isotopic fractionation indicate that the high salinity in groundwater originates not only from paleo–seawater but also from the dissolution of halite. Salty groundwater exhibits lower species richness and diversity than fresh groundwater. TDS, SO42–, and NO2– are the pivotal factors shaping the microbial community of salty groundwater, while NO3– and H2SiO3 are dominant variables influencing fresh groundwater community. This study identifies the order Alteromonadales, family Alteromonadaceae, and genus Marinobacter as potential biomarkers of seawater or paleo–seawater sources. Phylogenetic molecular network analysis of microbial communities illustrates that groundwater salinization results in a more compact microbial network but enhances microbial interactions. Predicted functional genes indicate that sulfate reduction genes (sat, met3, aprA, aprB, dsrA, and dsrB) are more abundant in salty groundwater than in fresh groundwater, suggesting a high metabolic potential for sulfate. These results elucidate the pivotal role of groundwater salinization in microbial community evolution, shaping specific functional zones in coastal groundwater.

Analysis of the microbial community diversity in various regions of the healthy oral cavity

BackgroundMicrobiomics offers new methods for conducting epidemiological surveys of oral microbiota in large populations. Compared to curette sampling, swab sampling is more convenient and less technically sensitive, making it more suitable for such surveys. To verify the feasibility of using swabs for buccal mucosa sampling in large-scale studies, we collected samples from the buccal mucosa and tooth surfaces of healthy individuals using both swabs and curettes. Microbiomics was employed to analyze and compare microbial abundance and diversity between these two methods.MethodsFour sites were assessed: the buccal mucosa on both sides and the buccal surfaces of the left and right mandibular first molars. Two sampling methods, swab and curette, were used to collect bacterial communities from healthy individuals. Specifically, buccal mucosa samples (n = 10) and tooth surface samples (n = 20) were analyzed using 16 S rDNA gene sequencing. Bacterial signals were detected through fluorescence in situ hybridization (FISH), targeting the bacterial 16 S rDNA gene. Metastats analysis and Wilcoxon test were used.ResultsA total of 383 OTUs were detected in the 30 samples, which belonged to 1 kingdom (bacteria), 11 phyla, 23 classes, 40 orders, 75 families, 143 genus, and 312 species. Among them, 223 OTUs were found on both the buccal mucosa and tooth surfaces. The statistics suggest that although there were no significant differences in colony composition, there were differences in the abundance and distribution of colonies on the dental and buccal mucosal surfaces. When detecting oral disease-causing pathogens such as Enterococcus faecalis and Porphyromonas gingivalis, the efficiency of detection is higher when using curette sampling. Compared to right tooth sampling with a curette, the swab sampling group had higher levels of Firmicutes, while Fusobacteria and Bacteroidetes were more prevalent in the curette tissues.ConclusionsIn oral health individuals, there is no difference in the bacterial composition of the oral buccal mucosa and the dental surface, differing only in abundance. Thus, the buccal mucosa can act as a substitute for the teeth in epidemiological investigations exploring the bacterial composition of the oral cavity.

Fecal Microbiota Transplantation Regulates Blood Pressure by Altering Gut Microbiota Composition and Intestinal Mucosal Barrier Function in Spontaneously Hypertensive Rats.

Hypertension is accompanied by gut microbiota imbalance, but the role of bacteria in the pathogenesis of hypertension requires further study. In this study, we used fecal microbiota transplantation to determine the impact of microbiota composition on blood pressure in spontaneous hypertensive rats (SHRs), using normotensive Wistar Kyoto (WKY) rats as controls. SHRs were randomly divided into two groups (n = 10/group), SHR and SHR-T (SHR plus fecal transplantation) and WKY into WKY and WKY-T (WKY plus fecal transplantation). SHR-T received fecal transplantation from WKY, while WKY-T received fecal transplantation from SHR. Blood pressure was measured from the tail artery in conscious rats. 16S rDNA gene amplicon sequencing was used to analyze bacterial composition. Circulating levels of diamine oxidase, D-lactate, FITC-Dextrans, and lipopolysaccharide were determined. Hematoxylin and eosin (H&E) staining was used to observe structural changes in the intestinal mucosa. Immunofluorescence, Western blot, and RT-PCR were utilized to determine changes in the expression of tight junction proteins. Following cross fecal transplantation, blood pressure decreased in SHR and increased in WKY. Significant differences in gut microbial composition were found between hypertensive and normotensive rats, specifically regarding the relative abundance of lactic and butyric acid-producing bacteria. Changes in gut microbiota composition also impacted the intestinal mucosal barrier integrity. Moreover, fecal transplantation affected the expression of tight junction proteins that may impact intestinal mucosal permeability and structural integrity. Blood pressure may be associated with butyric acid-producing intestinal microbiota and its function in regulating the integrity of intestinal mucosal barrier.

Morphological and molecular identification of metacestodes infecting teleost fishes of Moreton Bay, Australia

In a parasitological survey of fishes from Moreton Bay (southeastern Queensland, Australia), 169 teleost fishes, representing 54 species from 28 families, were examined for larval cestodes. Of these 54 species, 36 were found to be infected by metacestodes. Metacestodes were characterised by morphological and molecular data (the D1-D3 region of the 28S rDNA gene); these data were analysed in parallel to inform larval type allocation. Metacestodes collected represented eight morphological types, seven previously reported (Types I, II, IV, V, VI, VII, and X) and one novel type (Type XVI). Phylogenetic analyses were conducted to genetically match larval types to adult cestodes. Six of the eight larval types found were matched to adult forms: Type I metacestodes matched species of Phoreiobothrium Linton, 1889 (Onchobothriidae); Type II metacestodes matched species of Acanthobothrium van Beneden, 1849 (Onchobothriidae); Type IV metacestodes matched species of Scyphophyllidium Woodland, 1927 and Alexandercestus Ruhnke & Workman, 2013 (Phyllobothriidae); Type VI metacestodes matched species of Anthobothrium van Beneden, 1850 (Tetraphyllidea incertae sedis); Type X metacestodes matched species of Ambitalveolus Caira & Jensen, 2022 (Tetraphyllidea incertae sedis); and Type XVI metacestodes matched species of Platybothrium Linton, 1890 (Onchobothriidae). Based on phylogenetic topology, Type V metacestodes are inferred to match Pedibothrium Linton, 1909 (Balanobothriidae) and Type VII metacestodes are inferred to match Spongiobothrium Linton, 1889 (Rhinebothriidae). These findings support and extend the unified morphological type system proposed previously, but suggest that morphological types will ultimately be informative to identify metacestodes to a group of related genera rather than any distinct genus.

Analysis of nasopharyngeal microbiota revealing microbial disturbance associated with ovine respiratory complex

The ovine respiratory complex (ORC) is a complex respiratory disease process in ovine causing a significant health concern with substantial morbidity and mortality. It poses a significant threat of impacting animal health, leading to severe health consequences and considerable economic loss. Research on the upper respiratory tract (URT) microbiota is critical for offering insights into pathogenesis, prevention, and treatment strategies of ORC. The goal of this study is to compare the nasopharyngeal microbiota of clinically healthy Hu sheep (Group H) and sheep with ORC (Group P). The 16S rDNA gene amplicon high-throughput sequencing technique was applied to identify the microbial composition in the nasopharyngeal samples. The results showed that there was no significant difference in the microbiota diversity and richness between ORC and healthy sheep. However, there were significant differences in microbial composition, such as the relative abundance of Enterobacteriaceae, Moraxellaceae, Pasteurellaceae, and Streptococcaceae between the two groups. The abundance of aerobes in sheep with ORC increased significantly, while the abundance of anaerobes and facultative anaerobes decreased significantly. There were also differences in the taxa phenotypes associated with biofilm forming, mobile element-containing, oxidative stress-tolerance, and potential pathogens between the two groups. Our study showed the nasopharyngeal microbiota composition and its associated shifts between clinically healthy sheep and ORC sheep in China. These findings suggest that shifts in the nasopharyngeal microbiota could be a contributing factor to the pathogenesis of ORC, offering a potential avenue for the development of targeted interventions and treatments for this condition in sheep.

The Morphological and Molecular Characterization of the Avian Trematodes Harrahium obscurum and Morishitium dollfusi (Digenea: Cyclocoelidae) from the Middle Volga Region (European Russia).

The taxonomic status of many species of the family Cyclocoelidae is still unclear. Two species of cyclocoelids, Harrahium obscurum and Morishitium dollfusi, were collected from the air sacs of birds (Turdus merula and Tringa ochropus) inhabiting the Middle Volga region (European Russia). Here, we provide the first detailed morphological description of these cyclocoelids and combine it with the first molecular phylogenetic analysis of Cyclocoelidae from birds in Russia based on partial sequences of their 28s rDNA and coI mtDNA genes. Specimens of both flatworm species from different host individuals differ slightly in body shape and size, which probably reflects host-induced intraspecific variability. For the first time, we have shown that a stable morphological character such as the length of the vitelline fields in the studied digeneans is variable at the species level and cannot be used in their morphological diagnosis.

Development of a TaqMan-based multiplex real-time PCR for simultaneous detection of porcine epidemic diarrhea virus, Brachyspira hyodysenteriae, and Lawsonia intracellularis.

PEDV, Brachyspira hyodysenteriae, and Lawsonia intracellularis, are highly contagious diarrheal pathogens that have caused significant harm to the global swine industry. Co-infections with multiple pathogens are common, making it challenging to identify the actual causative agents depending only on clinical information. It is crucial to develop a reliable method to simultaneously detect and differentiate these pathogens. Based on the conserved regions of the M gene of PEDV, NADH oxidase gene of B. hyodysenteriae, and the 16S rDNA gene of L. intracellularis, specific probes and primers for the multiplex real-time PCR assay were designed. The concentrations of primers and probes were optimized using a matrix method. The approach demonstrated high specificity and no cross-reactivity with major pathogens related to diarrheal diseases. It showed high sensitivity with a detection limit of 10 copies/μL for B. hyodysenteriae and L. intracellularis, and 100 copies/μL for PEDV, respectively. It also demonstrated high reproducibility and stability with low coefficients of variation. Results from the multiplex real-time PCR method were in complete agreement with the commercial singleplex real-time PCR kit for detecting PEDV, B. hyodysenteriae and L. intracellularis. Clinical data revealed single infection rates of 31.46% for PEDV, 58.43% for B. hyodysenteriae, and 98.6% for L. intracellularis. The co-infection rates were 16.85% for PEDV + B. hyodysenteriae, 31.46% for PEDV + L. intracellularis, 57.86% for B. hyodysenteriae + L. intracellularis, and 16.85% for PEDV + B. hyodysenteriae + L. intracellularis, respectively. The new multiplex real-time PCR method can simultaneously differentiate PEDV, B. hyodysenteriae and L. intracellularis, making it a valuable diagnostic tool for preventing and controlling infectious diseases, as well as aiding in epidemiological investigations.

Neopestalotiopsis rosae, a novel pathogen causing leaf blight and crown rot of strawberries in India

Neopestalotiopsis have been reported to affect sustainable strawberry production across the world. Strawberry leaves with leaf blight symptoms were collected in January 2023 from the nurseries and fields of Department of Horticulture, Gandhi Krishi Vigyan Kendra, GKVK, Bangalore, India. Black conidiomata with slimy black conidial mass was produced upon incubating at 28 ± 2 °C. Conidia were fusoid to ellipsoidal, and comprised five cells. The middle three cells were versicolored. Whereas, the apical and basal cells harboured three to four and one appendages, respectively. Neopestalotiopsis rosae was confirmed based on sequencing of internal transcribed spacer (ITS) region of rDNA, β-tubulin (TUB2) and translation elongation factor 1-alpha (EF1-α) gene regions and phylogenetic analysis. Pathogenicity tests confirmed that Neopestalotiopsis rosae as the inciting agent of leaf blight and crown rot disease in strawberry posing a threat to strawberry production in India.

The first report of Bathynellacea in the subterranean water of Mongolia: A new species of Altainella Camacho, 2020 (Crustacea, Bathynellidae).

We report the first finding of Bathynellacea, discovered in Mongolia. We also report a new species of the genus Altainella Camacho, 2020, which was previously recorded only in the western edge of Russia. Altainellamongoliensis sp. nov. was found in the interstitial hyporheic region of the Onon River Basin, Mongolia, by inserting a core approximately 1.2 m deep and extracting the underground interstitial water. The new species exhibited sexual dimorphism in thoracopod VII, uniquely observed within the genus Altainella. We provide a morphological description and remarks on the new species with molecular information based on the 18S rDNA and partial CO1 gene sequences. We emphasise the need for continued research on the subterranean biodiversity in previously neglected regions by reporting the first discovery of macro-stygobionts in Mongolia.

Morphology and multigene phylogeny revealed four new species of Xylodon (Schizoporaceae, Basidiomycota) from southern China.

Fungi are one of the most diverse groups of organisms on Earth, amongst which wood-inhabiting fungi play a crucial role in ecosystem processes and functions. Four new wood-inhabiting fungi, Xylodoncremeoparinaceus, X.luteodontioides, X.poroides and X.wumengshanensis are proposed, based on morphological features and molecular evidence. Xylodoncremeoparinaceus is distinguished by a cream hymenial surface with a pruinose hymenophore, a monomitic hyphal system with clamped generative hyphae and ellipsoid basidiospores. Xylodonluteodontioides is characterised by flavescens hymenophore surface with odontioid hymenophore, monomitic hyphal system with clamped generative hyphae and ellipsoid basidiospores. Xylodonporoides bears coriaceous basidiomata with a poroid hymenophore surface, monomitic hyphal system with clamped generative hyphae and ellipsoid basidiospores. Xylodonwumengshanensis is a distinct taxon by its grandinoid hymenophore surface, monomitic hyphal system with clamped generative hyphae and ellipsoid basidiospores. Sequences of ITS and nLSU rRNA markers of the studied samples were generated and phylogenetic analyses were performed using the Maximum Likelihood, Maximum Parsimony, and Bayesian Inference methods. The phylogram, based on the ITS+nLSU rDNA gene regions, included three genera within the Schizoporaceae as Fasciodontia, Lyomyces and Xylodon. The four new species were grouped into the genus Xylodon. The topology, based on the ITS sequences, revealed that Xylodoncremeoparinaceus was grouped closely with X.pruinosus, X.detriticus and X.ussuriensis. The taxon X.luteodontioides was sister to X.nesporii. The species X.poroides separated from X.pseudotropicus, while X.wumengshanensis was grouped with four taxa: X.patagonicus, X.radula, X.subtropicus and X.taiwanianus.

Effect of crowding stress on liver health, gut permeability and gut microbiota of genetically improved farmed tilapia (GIFT, Oreochromis niloticus)

This study investigated the effects of crowding stress on liver and gut health in genetically improved farmed tilapia (GIFT, Oreochromis niloticus). Fish averaging 18.90 ± 0.01 g were reared at low (LD, 5 g/L) or high densities (HD, 100 g/L) for 14 days. The analysis revealed that the HD group significantly increased serum cortisol, glucose and adrenocorticotropic hormone (ACTH) levels in GIFT (P < 0.05). Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were elevated in the HD group (P < 0.05). TUNEL staining of liver tissues revealed that the fluorescence intensity indicating apoptosis was significantly higher in the HD group (P < 0.05). Additionally, the HD group exhibited increased expression of p53 and Caspase3 in the liver (P < 0.05). In comparison to the LD group, the HD group showed a significant increase in gut superoxide dismutase (SOD) and catalase (CAT) activities, as well as malondialdehyde (MDA) content (P < 0.05). The expressions of inflammatory-related genes (tnfα, il-1β, il-8, and il-6) and pro-apoptotic genes (p53 and Caspase7) were significantly upregulated in the gut of the HD group (P < 0.05). Serum contents of D-lactate and diamine oxidase (DAO) were significantly elevated in HD group as comparison to LD group (P < 0.05), and significantly higher serum FITC-CM-dextran was observed in HD group versus LD group following oral gavage (P < 0.05). Furthermore, the HD group down-regulated the expressions of gut tight junction proteins (tjp2a, hif-1a, and zo-1) (P < 0.05), and significantly up-regulated the protein expression of phosphorylated myosin light chain 2 (P-MLC2) (P < 0.05). The 16S rDNA gene sequencing results indicated that the relative abundance of Cetobacterium was significantly lower (P < 0.05), and Enterovibrio and Weissella were significantly higher in the HD group (P < 0.05). Overall, crowding stress negatively affects GIFT liver and gut health, which is caused by inducing hepatic and intestinal apoptosis, impairing intestinal barrier function, and disrupting the gut microbiota.

Ethnicity-based analysis of supragingival plaque composition and dental health behaviours in healthy subjects without caries

ObjectiveThe primary objective of this study was to scrutinise the disparities in the diversity, structure, and function of the oral microbiome among caries-free children from the Zhuang and Han ethnic groups with a focus on the influence of ethnically distinct oral health behaviours on the composition of the oral microbiota. MethodsA questionnaire survey was conducted to assess oral health behaviours and dental plaque samples were collected from 96 Zhuang and Han children aged 4–5 years living in Guangxi, southern China for high-throughput sequencing. PCR amplification was performed for sequencing of the V4 region of the 16S rDNA gene, and second-generation sequencing was performed using the Illumina MiSeq platform to compare and analyse the diversity, structure and function of the microbiota. ResultsSingle-factor analysis revealed significant differences between the Zhuang and Han ethnic groups regarding juice consumption, the frequency of consuming sugar-sweetened food or beverages before bedtime, the age that individuals started toothbrushing, the frequency of toothbrushing and the frequency of parental assistance with toothbrushing (p < 0.001). The dominant phyla were Proteobacteria, Firmicutes, etc., and the dominant genera included Streptococcus and Neisseria. The dental plaques of the caries-free Zhuang and Han ethnic groups had similar core microbiomes, with no significant differences in the diversity and structure of the microbiota and no significant differences in the abundance of the dominant genera. In addition, no significant difference in metabolic function was observed between the Zhuang and Han ethnic groups. ConclusionThe core oral microbiota was consistent in caries-free Zhuang and Han children. Despite differences in dietary habits and oral hygiene behaviours between the Zhuang and Han ethnic groups, with a high frequency of sugary food intake but better oral health behaviours in the Zhuang group, there were no significant differences in the diversity, structure and function of the oral microbiota of caries-free children in the Zhuang and Han ethnic groups.

NEW INSIGHTS BASED ON MORPHOLOGICAL AND MOLECULAR DATA REVEAL THE TAXONOMIC STATUS OF HALIOTREMA PTEROISI (MONOGENOIDEA: DACTYLOGYRIDAE) INFECTING DEVIL FIREFISH PTEROIS MILES (PERCIFORMES: SCORPAENOIDEI: SCORPAENIDAE) IN THE RED SEA OFF EGYPT.

Paperna, 1972 (Monogenoidea: Dactylogyridae) was found parasitizing the gill lamellae of devil firefish, Pterois miles (Bennet) (Perciformes: Scorpaenidae), in the Red Sea off Safaga (26°44'N, 33°56'E), Egypt. The parasite species was described based on morphological features of available specimens and transferred to PlatycephalotremaKritsky and Nitta, 2019 (Dactylogyridae) as Platycephalotrema pteroisi (Paperna, 1972) n. comb. The occurrence of Pl. pteroisi off Safaga, Egypt, represented a range extension for the helminth of about 160 km to the southwest of the southern end of the Gulf of Aqaba. The transfer of the species to Platycephalotrema based on an evaluation of morphological features was supported by an analysis of molecular sequences of the 28S rDNA gene of Pl. pteroisi and 49 other dactylogyrid species. Maximum-likelihood, Bayesian inference, and maximum parsimony analyses of this dactylogyrid sequence data revealed H. pteroisi to nest with significant support within the clade of Platycephalotrema spp. During the literature review of dactylogyrid species infecting scorpionfishes, it was determined that Ancyrocephalus sp. of Dyer et al. from luna lion fish Pterois lunulata Temminck and Schlegel collected off Okinawa-jima, Japan represented an undescribed species of Platycephalotrema.