rDNA Gene Research Articles

Study on the protective effect of Aronia melanocarpa extract on type 2 diabetes by regulating glucose and lipid metabolism through intestinal flora.

Aronia melanocarpa, a plant rich in anthocyanins, has been studied for its potential to regulate blood sugar and blood lipids, although the specific mechanism is not yet understood. This research aims to identify the differential bacterial flora and elucidate the mechanism by which it improves glucose and lipid metabolism disorders through 16S rDNA gene sequencing. The study reveals the protective effect of Aronia melanocarpa extract (AME) on liver damage in type 2 diabetic rats. Experimental results demonstrate that AME can effectively modulate the abundance of intestinal flora, reduce colon tissue damage, enhance the weight of diabetic rats, and lower levels of fasting blood sugar, low-density lipoprotein (LDL), and triglycerides (TG). Additionally, liver morphology analysis shows that AME can effectively mitigate liver tissue structural damage in type 2 diabetic rats. In conclusion, AME regulates glucose and lipid metabolism by influencing intestinal flora, ultimately regulating glucose and lipid metabolism in type 2 diabetic rats.

Alterations in the Salivary Microbiome and Metabolism in Patients With Carotid Atherosclerosis from Rural Northeast China.

Periodontitis and atherosclerosis are both chronic inflammatory diseases with a high prevalence. Increasing evidence supports the independent association between severe periodontitis and atherosclerotic cardiovascular disease, in which oral microorganisms may play an important role. We aimed to evaluate the characteristic changes of salivary microbiome and metabolome in patients with carotid atherosclerosis (CAS) and periodontitis. The subjects were obtained from a cross-sectional study that included 1933 participants aged 40 years or older from rural northeast China. The study enrolled 48 subjects with CAS and 48 controls without CAS matched by sex, age, body mass index, and prevalence of hypertension, diabetes, and dyslipidemia. We performed full-length 16S rDNA gene sequencing and untargeted metabolomics of saliva samples from 96 subjects. We found that CAS was closely associated with an increased abundance of Streptococcus, Lactobacillus, and Cutibacterium. Furthermore, patients with CAS had higher prevalence of severe periodontitis than the control group. Notably, periodontal pathogens such as Tannerella and Anaeroglobus were not only associated with periodontitis but also enriched in patients with CAS, whereas periodontal health-associated Neisseria was more abundant in those without CAS. We also identified 2 lipid metabolism pathways, including glycerophospholipid and sphingolipid metabolism, as associated with CAS. The levels of trimethylamine N-oxide and inflammatory mediator leukotriene D4 were significantly higher in patients with CAS, whereas the levels of carnosine were significantly lower, than those in controls. Additionally, serum levels of inflammatory marker high-sensitivity C-reactive protein were significantly increased in CAS and positively correlated with the abundance of Anaeroglobus and leukotriene D4 in saliva. Our study suggests that characteristic changes in salivary microbiota and metabolites are closely related to CAS, and periodontitis and associated microorganisms may be involved in the initiation and progression of CAS.

Bacterial Communities across Multiple Ecological Niches (Water, Sediment, Plastic, and Snail Gut) in Mangrove Habitats.

Microbial composition across substrates in mangroves, particularly in the Middle East, remains unclear. This study characterized bacterial communities in sediment, water, Terebralia palustris snail guts, and plastic associated with Avicennia marina mangrove forests in two coastal lagoons in the Sea of Oman using 16S rDNA gene MiSeq sequencing. The genus Vibrio dominated all substrates except water. In the gut of snails, Vibrio is composed of 80-99% of all bacterial genera. The water samples showed a different pattern, with the genus Sunxiuqinia being dominant in both Sawadi (50.80%) and Qurum (49.29%) lagoons. There were significant differences in bacterial communities on different substrata, in particular plastic. Snail guts harbored the highest number of unique Operational Taxonomic Units (OTUs) in both lagoons, accounting for 30.97% OTUs in Sawadi and 28.91% OTUs in Qurum, compared to other substrates. Plastic in the polluted Sawadi lagoon with low salinity harbored distinct genera such as Vibrio, Aestuariibacter, Zunongwangia, and Jeotgalibacillus, which were absent in the Qurum lagoon with higher salinity and lower pollution. Sawadi lagoon exhibited higher species diversity in sediment and plastic substrates, while Qurum lagoon demonstrated lower species diversity. The principal component analysis (PCA) indicates that environmental factors such as salinity, pH, and nutrient levels significantly influence bacterial community composition across substrates. Variations in organic matter and potential anthropogenic influences, particularly from plastics, further shape bacterial communities. This study highlights the complex microbial communities in mangrove ecosystems, emphasizing the importance of considering multiple substrates in mangrove microbial ecology studies. The understanding of microbial dynamics and anthropogenic impacts is crucial for shaping effective conservation and management strategies in mangrove ecosystems, particularly in the face of environmental changes.

Identification and biological control of bacterial leaf spot disease of cucurbits

Objective: The present study was conducted for isolation and detection of the phyto-pathogen responsible for bacterial leaf spot disease of cucurbits as well as evaluation of its biological control techniques. Methods: The pathogen of the disease was isolated from infected leaf of bitter gourd and cultured on Luria-Bertani (LB) growth medium. The morphological tests and biochemical tests revealed the isolated bacteria as gram negative. Furthermore, advanced molecular technique was applied to facilitate proper detection of the isolated bacteria. The PCR of the bacterial genomic DNA using specific primers generated clear band of approximately 1450 bp in gel electrophoresis. Results: In gram staining test, the bacterial strain was found to be rod shaped and pinkish in color and Gram-negative. All the biochemical test showed positive without mannitol salt agar. The nucleotide sequencing of 16S rDNA gene of the bacterial isolate showed 86.02% similarities with the original sequence of Xanthomonas cucurbitae. In antibiotic sensitivity assay, the antibiotic cefixime showed highest 28.0±0.7 mm diameter of inhibition zone against the tested bacteria. The highest antibacterial activity was 8.0±0.5 mm zone of inhibition by of Allium sativum. Conclusion: The present findings may be benevolent for the detection, characterization and development of biological control techniques to prevent the leaf spot disease of cucurbits crops in Bangladesh. It may help to find out the specific signaling pathway techniques for plant microbes relationship for disease formation in future.

Probiotic Potential of Lactobacillus and Enterococcus Strains Isolated From the Faecal Microbiota of Critically Endangered Hangul Deer (Cervus hanglu hanglu): Implications for Conservation Management.

The mammalian gut microbiota plays a crucial role in promoting host health, and lactic acid bacteria (LAB) are commonly employed as probiotics for their beneficial effects. The Hangul deer (Cervus hanglu hanglu), a critically endangered red deer subspecies found in the Indian subcontinent, requires meticulous health management for its conservation. This pioneering study aimed to isolate, identify, and evaluate the in-vitro probiotic functional properties of LAB strains from the faeces of Hangul deer. A total of 27 LAB strains were isolated and identified using 16S rDNA gene sequencing, followed by comprehensive probiotic characterization and safety assessment. Remarkably, four species exhibited robust resistance and survivability against varying pH levels and bile salts, along with high aggregation and co-aggregation capacities. Notably, Lactobacillus acidophilus and Enterococcus mundtii strains displayed antibacterial activities. Safety assessment revealed the absence of hemolytic activity and virulence genes in all four strains. Antibiotic susceptibility testing showed that Lactobacillus acidophilus and Enterococcus casseliflavus were susceptible to all tested antibiotics, while Enterococcus mundtii exhibited resistance to clindamycin, and Enterococcus gallinarum exhibited resistance to erythromycin. These findings suggest that the isolated LAB strains possess advantageous probiotic characteristics and hold potential as dietary supplements for promoting the health and disease management of Hangul deer.

Pathogenic Leptospira interrogans in Jos North Abattoir, Nigeria: Occurrence, serology, and molecular characterization

Leptospirosis, a neglected zoonotic disease, adversely affects animal, human health, and socioeconomic conditions, particularly in developing countries like Nigeria. This study aimed to determine the occurrence and molecular identification of pathogenic Leptospira spp. among abattoir workers, cattle, and rats in Jos North, Plateau State, Nigeria. Using a cross-sectional study design, a total of 394 samples were collected, including 149 urine samples from abattoir workers, 125 urine samples from cattle bladders, and 120 bladders from trapped rats. Samples were processed and cultured in Ellinghausen McCullough Johnson Harrison (EMJH) medium and examined under a darkfield microscope. Positive cultures were confirmed using the Microscopic Agglutination Test (MAT) and nested Polymerase Chain Reaction (N-PCR) targeted the 16 S rDNA gene. Results revealed a prevalence of 33.76 % for Leptospira spp. across all samples, with the highest occurrence in abattoir workers (13.96 %), followed by rats (13.45 %), and cattle (6.35 %). The MAT showed L. interrogans serovar Hardjo str. Hardjoprajitno as the most prevalent serotype (41.61 %), followed by L. interrogans serovar Icterohaemorrhagiae str. RGA (34.31 %). N-PCR confirmed the presence of pathogenic Leptospira spp., showing bands of 1200 bp. Phylogenetic analysis of the 16 S rDNA gene sequences revealed close similarities to known pathogenic Leptospira strains from Brazil and the USA. The study underscores the significant public health risk posed by leptospirosis in Jos North and highlights the need for improved diagnostic capabilities, increased awareness, and effective control measures to mitigate the disease burden. Enhanced surveillance and preventive strategies are crucial to protect both animal and human health in the region.

Molecular identification of Mymarothecium viatorum and Anacanthorus penilabiatus in extensive native fish farming systems of the Peruvian Amazon

Piaractus brachypomus (Pacú) is the main native fish species cultivated in Peru and holds great potential for growth in aquaculture from the Peruvian Amazon. Between October 2021 and January 2022 in two fish producing farms in the Amazon region of San Martín in Peru, P. brachypomus individuals were examined for parasite evaluation. A total of 6366 monogeneans were isolated from the gills of 30 fish, revealing a prevalence of 100%, with an abundance and mean intensity of 212 parasites per fish. Monogeneans were morphologically identified as Mymarothecium viatorum and Anacanthorus penilabiatus. The genetic divergence in the 28S rDNA gene found among A. penilabiatus sequences was 0.1% and among Anacanthorus spp. it ranged from 0.9% to 7.5%. The genetic divergence found among the M. viatorum sequences was 0.3%. These finding represents the first molecular data of M. viatorum and A. penilabiatus in Peru using the 28S rDNA gene of these monogeneans. The new sequences obtained will contribute to future studies on the phylogenetic relationships among dactylogyrids. However, further research with a broader range of host-parasite samples and additional genetic markers is needed to clarify these relationships and provide stronger support for the phylogenetic positions.

Metabolism of quercitrin in the colon and its beneficial regulatory effects on gut microbiota.

Quercitrin is a dietary flavonoid widely found in plants with various physiological activities. However, whether quercitrin alters gut microbiota in vivo is not well understood. The aim of this study was to investigate metabolism of quercitrin in the colon and its regulation on gut microbiota in mice. Herein, 22 flavonoids related to quercitrin metabolism were identified based on ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS). Gas chromatography and 16S rDNA gene sequencing were used to investigate short-chain fatty acid (SCFA) content and diversity of composition of gut microbiota, respectively. The results showed that quercitrin significantly alters the beta-diversity of the gut microbiota, probiotics such as Akkermansia and Lactococcus were significantly increased, and the production of propanoate, isovalerate and hexanoate of the quercitrin group were enhanced significantly. The Spearman's association analysis provided evidence that Gardnerella and Akkermansia have obvious correlations with most of quercitrin metabolites and SCFAs. Quercitrin and its metabolites in the colon altered the structure of the mice gut microbiota and increased the content of SCFAs. Our experiments provide valuable insights into quercitrin research and application. © 2024 Society of Chemical Industry.

Isolation and Identification of Isolate, S1 with High Biotransformation Potential of Ferulic Acid to Vanillin

Nine actinobacterial isolates were purified from the sediment sample of Kogilvai village, Warangal, Telangana, based on their capability to grow on the minimal medium with Ferulic acid (FA) as only Carbon (C) source. FA to Vanillin conversion capacity of these isolates was identified by Thin-layer chromatography (TLC). Biotransformation of FA to Vanillin was high by four isolates, S1, S3, O3 and O4 when compared to other five isolates (O1, O2, S2, S4 and S5) with initial pH 7 in basal medium. Among these four isolates, optimal and rapid FA to Vanillin bioconversion of 140 mg/L was shown by isolate S1 with UV-spectrophotometry. Its conversion was confirmed by High Performance Liquid Chromatography (HPLC) analysis with retention time of 2.9 min after 28hrs of incubation at 37°C with 1g/L ferulic acid in the medium with 150 rpm. Isolate S1 could utilize Lactose, Maltose, Glycerol, Fructose, Galactose, Sucrose, Dextrose, L-Arabinose, ONPG, Esculin and not other carbohydrates present in the Himedia Hicarbo kit. Molecular characterization showed that 16S rDNA gene sequence of isolate S1 was 98.27% similar to Limosilactobacillus fermentum CECT 562 with completeness of 96.7% and was identified as Limosilactobacillus sp. 16S rDNA gene sequence of isolate S1 was submitted to NCBI GenBank and its accession number was OR136396. As this isolate has high potential of FA to Vanillin biotransformation capacity, it can be further explored to be used for industrial setups for commercial exploitation.

Dasyrhynchus giganteus plerocercoids encysting in the musculature of Indian halibut (Psettodes erumei): seasonal prevalence, morpho-molecular characterization, and histopathological alterations

This study investigated the prevalence, morphology, molecular identification, and histopathological effects of larval tapeworms (plerocercoids) infecting the skeletal muscles of the Indian halibut (Psettodes erumei) collected from the coastal waters of the Arabian Gulf. Numerous oval or round blastocysts, measuring 13–26 mm, were found embedded within the muscular tissues of the Indian halibut, rendering the fish unsuitable for human consumption. Morphological and molecular analyses identified the plerocercoids as Dasyrhynchus giganteus (family Dasyrhynchidae), with an overall prevalence of 15.4%. The seasonal prevalence was the highest in summer (14.6%), followed by spring (10.6%), winter (4.4%), and autumn (3.5%). Infection rates increased with fish size. Histopathological examination revealed fibrous connective tissue capsules surrounding the larvae, causing muscular atrophy and degenerative changes, with few inflammatory eosinophilic cells. Molecular and phylogenetic analysis of the 28S rDNA gene sequences confirmed the specimens as D. giganteus, clustered closely with other sequences of D. giganteus with 100% bootstrap values. This study provided valuable insights into the parasitic infection dynamics, seasonal variation, molecular identification, and histopathological effects, highlighting the importance of monitoring fish for food safety and public health implications.

DNA barcoding and phylogenetic relationships of ecologically and commercially important seaweed species from the Azores (NE Atlantic)

Marine natural resources are increasingly demanded to support the livelihoods and wellbeing of humans facing multiple and simultaneous crises across the planet. Seaweeds, in particular, are renowned sources of bioactive marine compounds used for various purposes, including human and animal nutrition, soil fertilization, and healthcare markets. DNA-based tools are being adopted in integrative taxonomy and ecological research, as well as to monitor the supply chain of commercially important species. This research provides novel insights into the population genetics, phylogenetic relationships, and haplotype network of six commercially significant seaweed species that are abundant in the Azores archipelago and currently traded for industrial applications. This study provides a detailed assessment of the genetic diversity of the red seaweeds Asparagopsis armata, Asparagopsis taxiformis, and Pterocladiella capillacea, and the brown seaweeds Halopteris scoparia, Zonaria tournefortii, and Cystoseira pustulata, contributing with 17 newly generated barcodes of COI, rbcL, and 28S rDNA gene records from the Azores region to the reference databases. Understanding the species identification and population dynamics is critical for understanding species composition in biodiversity hotspots. This knowledge supports taxonomy, conservation, environmental protection, and the sustainable use of marine resources.

Isolation, Selection, and Identification of Keratinolytic Bacteria for Green Management of Keratin Waste.

The volume of difficult-to-process keratin waste is increasing as a result of rising global meat production. If not properly managed, this waste can contribute to environmental pollution and pose a threat to human and animal welfare. An interesting and more sustainable alternative is therefore the bioconversion of keratin using microorganisms and their enzymes. This work aimed to isolate bacteria from soil samples and zoonotic keratins and to evaluate their enzymatic capacity to degrade α- and β-keratin wastes. A total of 113 bacterial strains were isolated from environmental samples and subjected to taxonomic identification using the MALDI-TOF MS technique and to a two-step screening for proteolytic and keratinolytic activity. The ability to degrade a β-rich keratin substrate was observed in almost all of the strains isolated from soil and horsehairs. In contrast, when an α-rich keratin substrate was used, the highest levels of hydrolysis were observed only for Ker39, Ker66, Ker85, Ker100, and Ker101. Strains with the highest biodegradation potential were identified using molecular biology methods. Phylogenetic analysis of 16S rDNA gene sequences allowed the assignment of selected keratinolytic microorganisms to the genera Exiguobacterium, Priestia, Curtobacterium, Stenotrophomonas, Bacillus, Kocuria, or Pseudomonas. The results of this study are a promising precursor for the development of new, more sustainable methods of managing keratin waste to produce high-value hydrolysates.

Different ploidy-level hybrids derived from female common carp × male topmouth culter

Distant hybridization is an effective strategy for creating polyploids in fish genetic breeding. In this study, the cross of common carp (Cyprinus carpio, 2n = 100, COC, ♀) and topmouth culter (Culter alburnus, 2n = 48, TC, ♂), which belonged to different subfamilies, was conducted and obtained surviving hybrid offspring (CT hybrids). Based on the measurement of DNA content and chromosomal numbers, three ploidy levels of CT hybrids were identified: diploid hybrids (2n = 74, 2nCT), triploid hybrids (3n = 124, 3nCT), and tetraploid hybrids (4n = 148, 4nCT). Analyses of countable traits and measurable traits indicated a significant similarity between CT hybrids and COC in comparison to TC. The genetic variation analysis of 5S rDNA and HoxD10a gene in CT hybrids revealed the retention of all COC genotypes and the partial elimination of TC genotypes, as well as the generation of novel variant genotypes (derived from TC genotypes) and recombinant genotypes (derived from parental genotypes), which suggested that in CT hybrids, the paternal subgenome exhibited greater instability than the maternal subgenome. In addition, the droplet digital PCR (ddPCR) method, combining allele-specific probes targeting the EPHX2 gene, was employed for the first time to investigate the genome composition of hybrids. The results showed that the ratios of COC-allele number to TC-allele number were approximately 1 in 2nCT, 2 in 3nCT, and 1.5 in 4nCT, respectively, which confirmed the hybridization origins for each type and effectively distinguished between the three CT hybrids. The obtainment of CT hybrids harbors potential benefits and application in aquaculture and provides an ideal model for understanding the influence of hybridization and polyploidization on the genomic composition of fish species.

Assessing the role of field isolated Pseudomonas and Bacillus as growth‐promoting rizobacteria on avocado (Persea americana) seedlings

AbstractIntroductionThis research aims to assess the efficacy of two genera of rhizobacteria from avocado field isolated: Pseudomonas and Bacillus, as plant growth‐promoting microorganisms in Hass avocado trees grafted onto Zutano rootstock.Materials and MethodsThe siderophore‐producing and phosphate‐solubilizing capacity of each isolated strain was determined and plant growth‐promoting activity, nutrient accumulation, and nutrient use efficiency in Zutano variety avocado seedlings were evaluated. Molecular identification was carried out by amplification of the 16S rDNA gene of the isolated strains.ResultsPseudomonas putida, Lysinibacillus macroides, Lysinibacillus xylanilyticus, Lysinibacillus fusiformis, Bacillus subtilis and Pseudomonas plecoglossicida, were identified as the PGPR of the Bacillus and Pseudomonas genera, predominant in the avocado rhizosphere. There was found 11 phosphate solubilizing strains and 2 siderophore‐producing strains. The phosphate‐solubilizing strains, B. subtilis and P. plecoglossicida, stimulated the growth of Zutano seedlings, increasing their root dry weight (g), stem dry weight (g), leaf dry weight (g) and leaf area (cm2). Significant differences were found in nutrient uptake efficiency between inoculated plants and noninoculated plants. The increase in root biomass responded to greater phosphorus and potassium absorption in plants inoculated with P. plecoglossicida, due to this strain's high phosphate solubilization efficiency (266%).ConclusionsThe highest plant growth promotion strains were Bac F (B. subtilis), Bac M (P. plecoglossicida) and P1 (P. putida), which achieved the highest increase in root and leaf dry weight, as well as the highest nutrient extractions and nutrient uptake efficiency.

Valorization of Sugarcane Bagasse for Co-Production of Poly(3-hydroxybutyrate) and Bacteriocin Using Bacillus cereus Strain S356.

Poly(3-hydroxybutyrate) (P(3HB)) is an attractive biodegradable plastic alternative to petroleum-based plastic. However, the cost of microbial-based bioplastic production mainly lies in the cultivation medium. In this study, we screened the isolates capable of synthesizing P(3HB) using sugarcane bagasse (SCB) waste as a carbon source from 79 Bacillus isolates that had previously shown P(3HB) production using a commercial medium. The results revealed that isolate S356, identified as Bacillus cereus using 16S rDNA and gyrB gene analysis, had the highest P(3HB) accumulation. The highest P(3HB) yield (5.16 g/L, 85.3% of dry cell weight) was achieved by cultivating B. cereus S356 in an optimal medium with 1.5% total reducing sugar with SCB hydrolysate as the carbon source and 0.25% yeast extract as the nitrogen source. Transmission electron microscopy analysis showed the accumulation of approximately 3-5 P(3HB) granules in each B. cereus S356 cell. Proton nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy analyses confirmed that the polymer extracted from B. cereus S356 was P(3HB). Notably, during cultivation for P(3HB) plastic production, B. cereus S356 also secreted bacteriocin, which had high antibacterial activity against the same species (Bacillus cereus). Overall, this work demonstrated the possibility of co-producing eco-friendly biodegradable plastic P(3HB) and bacteriocin from renewable resources using the potential of B. cereus S356.

Characterization of CO1 and 18S rDNA Gene from The Domesticated Indonesian Native Ornamental Shrimp Caridina boehmei

Characterization of CO1 and 18S rDNA Gene from The Domesticated Indonesian Native Ornamental Shrimp Caridina boehmei

Identification of entomopathogenic nematodes in Hainan Province, China and their efficacy against Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a notorious migratory pest native to tropical and subtropical America. It invaded China in 2018 and can reproduce annually in Hainan Province. Entomopathogenic nematodes (EPNs) have gained interest as potential bioagent due to as an alternative to conventional pesticides are EPNs. We isolated 19 EPNs out of 155 soil samples using the Galleria-baiting method. This was the first comprehensive survey of EPNs in Hainan Province. Phylogenetic analyses of the ITS and D2D3 expansion region of the 28S rDNA gene were performed, and 19 strains belonging to Steinernema aciari, Steinernema sp., Heterorhabditis sp., Oscheius sp., Oscheius myriophilus and O. amsactae were identified. It was shown that S. aciari 22,000 caused 100% and 96% mortality to the third and sixth instar larvae of S. frugiperda, respectively. When the pupae of S. frugiperda were exposed to S. aciari 22,000, the pupae died after emergence. Our study suggests S. aciari 22,000 is a promising indigenous biocontrol agent against S. frugiperda in the future. These findings underscore the importance of continued investigation into the potential of indigenous EPNs for sustainable management strategies of S. frugiperda in agricultural areas.

Highly Diverse Symbiodiniaceae Types Hosted by Corals in a Global Hotspot of Marine Biodiversity

Symbiotic dinoflagellates in the genus Symbiodiniaceae play vital roles in promoting resilience and increasing stress tolerance in their coral hosts. While much of the world’s coral succumb to the stresses associated with increasingly severe and frequent thermal bleaching events, live coral cover in Papua New Guinea (PNG) remains some of the highest reported globally despite the historically warm waters surrounding the country. Yet, in spite of the high coral cover in PNG and the acknowledged roles Symbiodiniaceae play within their hosts, these communities have not been characterized in this global biodiversity hotspot. Using high-throughput sequencing of the ITS2 rDNA gene, we profiled the endosymbionts of four coral species, Diploastrea heliopora, Pachyseris speciosa, Pocillopora acuta, and Porites lutea, across six sites in PNG. Our findings reveal patterns of Cladocopium and Durusdinium dominance similar to other reefs in the Coral Triangle, albeit with much greater intra- and intergenomic variation. Host- and site-specific variations in Symbiodiniaceae type profiles were observed across collection sites, appearing to be driven by environmental conditions. Notably, the extensive intra- and intergenomic variation, coupled with many previously unreported sequences, highlight PNG as a potential hotspot of symbiont diversity. This work represents the first characterization of the coral-symbiont community structure in the PNG marine biodiversity hotspot, serving as a baseline for future studies.

Profiles of Antibiotic Resistance Genes in the Coastal Aquatic Environment of Xiamen City

The coastal areas and the adjacent islands are the hotspots of human economic and social activities, including urbanization, industrialization, and agricultural practices, which have profound impacts on the ecological environment of the coastal environment. Antibiotic resistance genes （ARGs）, as emerging contaminants, have become hot topics in water ecological security and public concern. However, the profiles of antibiotic resistome in the costal water remain largely unknown, impeding resistome risk assessment associated with coastal environments. In this study, the high-throughput quantitative PCR technique was used to investigate the abundance and distribution of ARGs in the coastal environment of Xiamen City. Combined with the 16S rDNA gene amplicon sequencing method, the structure and composition of the microbial community in a water environment were investigated, and the influencing factors and associated mechanism of ARGs in seawater were deeply explained. The results of this study showed that a total of 187 ARGs were detected in the coastal water environment, and the abundance level was up to 1.29×1010 copies·L-1. Multidrug resistance, aminoglycosides, and β lactamase resistance genes were the three main classes of antibiotic resistance genes in the water environment of the Xiamen coastal zone. On the whole, the profile of ARGs was of high abundance, great diversity, and common co-existence, and the coastal water environment was an important hot area and reservoir for antibiotic resistance genes. Twenty-two microbes, including Nautella, Candidatus, Tenacibaculum, Rubripirellula, and Woeseia, were potential carriers of the corresponding 16 antibiotic resistance genes. The mobile genetic elements （MGEs） and microbial community structure accounted for 93.9% of the variation in environmental resistance genes in water. Therefore, microbial community and its mobile genetic elements were the most important driving forces for the occurrence and evolution of ARGs in coastal waters. Based on the results, it is implied that the environmental antibiotic resistance genes in the waters near Xiamen Island have potential risks to water ecological security and human health and highlight the necessity for comprehensive surveillance of ARGs associated with microbial contamination in the coastal aquatic environment.

Morphological and molecular characterization of Eimeria magna infecting local rabbit (Oryctolagus cuniculus) in Alkarg City, Saudi Arabia.

Coccidiosis is one of the most prevalent diseases found in local rabbits (Oryctolagus cuniculus), which is caused by the Eimeria. The study aimed to more reliably identify Eimeria species (Eimeria magna) infecting Local Rabbits in Alkarg City, Saudi Arabia, based the method on the molecular properties and morphological and molecular biological techniques. Sub-spheroidal oocysts measuring 21-27 × 12-16 (24 × 14.4) μm (20 n) and with a length/width (L/W) ratio of 0.9-1.1 (1.0) were identified by microscopic analysis of a fecal sample. Oocysts feature a bi-layered wall that is 1.0-1.2 (1.1) μm thick. About two-thirds of the wall's thickness is made up of a smooth outer layer. A polar granule is present, but neither a micropyle nor an oocyst residuum is present. The ovoidal sporozoites measure 15-18 × 8-11 (16.5 × 9.5) μm, have an L/W ratio of 1.6-1.8 (1.7), and take up around 21% of the oocyst's total surface. The mean size of the sub-Stieda body is 1.4 × 2.3 μm, while the average size of the Stieda body is 0.9 × 1.8 μm. The para-Stieda body is lacking. Sporocyst residuum appears membrane-bound and has an uneven form made up of several granules. With two refractile bodies below the striations and pronounced striations at the more pointed end, sporozoites are vermiform, measuring an average of 11.6 × 4.0 μm. The results of the sequencing for the 18S rDNA gene confirmed the species of Eimeria parasites found in the host (rabbits). The current parasite species is closely related to the previously described and deposited E. magna and deeply embedded in the genus Eimeria (family Eimeriidae). According to the findings, single oocyst molecular identification of Eimeria may be accomplished through consistent use of the morphological and molecular results. It is possible to draw the conclusion that the current research supplies relevant facts that help assess the potential infection and future control measures against rabbit coccidiosis to reduce the financial losses that can be incurred by the rabbit industry in Saudi Arabia.