Preliminary Study on Microplastic Contamination in Black Sea Cetaceans: Gastrointestinal Analysis of Phocoena phocoena relicta and Tursiops truncatus ponticus.

Plastic pollution is a global concern that has a significant impact on marine life. Plastic is widely used and has become a pervasive pollutant in marine environments. Plastic contamination has been documented both in marine environments and biota. Plastic contamination in cetacean gastro-intestinal tract (GIT) content has received limited attention, especially in the Black Sea. This study aims to investigate plastic contamination in the GITs of bottlenose dolphins and harbour porpoises, introducing a novel methodology. Given the limited exploration of this issue in the Black Sea, the research predominantly focuses on microplastic contamination. The GITs were sampled through necropsy from stranded and by-caught cetaceans, and content was washed through a multi-sieves tool. The material retained on each sieve was analysed following specific protocols. All (100%) of the GITs contained plastics (meso- and microplastics). In total, 1059 items (fibres, fragments, and beads) ranging from 22.86 µm to 5776 µm were found, suggesting a high contamination level in the Black Sea cetaceans. Future efforts should concentrate on increasing the number of samples and using the results for the implementation of the Marine Strategy Framework Directive (MSFD).

Piezo channels in the intestinal tract.

The intestine is the largest mechanosensitive organ in the human body whose epithelial cells, smooth muscle cells, neurons and enteroendocrine cells must sense and respond to various mechanical stimuli such as motility, distension, stretch and shear to regulate physiological processes including digestion, absorption, secretion, motility and immunity. Piezo channels are a newly discovered class of mechanosensitive ion channels consisting of two subtypes, Piezo1 and Piezo2. Piezo channels are widely expressed in the intestine and are involved in physiological and pathological processes. The present review summarizes the current research progress on the expression, function and regulation of Piezo channels in the intestine, with the aim of providing a reference for the future development of therapeutic strategies targeting Piezo channels.

Transporter-mediated Nano-delivery System in Promoting Oral Absorption of Drugs：A Review / 中国实验方剂学杂志

Oral administration is the most convenient way of drug delivery， but due to the existence of intestinal barrier， the oral bioavailability of drugs is generally low， especially for drugs with low water solubility， poor permeability and macromolecules. For decades， researchers have demonstrated that nano-delivery system is one of the most effective strategies to solve this problem， but nano-delivery systems have shown limited improvement in the oral bioavailability of drugs. Therefore， researchers have proposed to use transporter-mediated nano-delivery systems to promote the oral absorption of drugs. The intestinal tract were highly expressed as a transporter for ingesting various nutrients（such as glucose， oligopeptides and bile acids）， which was an excellent target of oral drug delivery system. Its substrate were modified on the nano-delivery system， and the loaded drugs could cross the intestinal barrier and enter the systemic circulation more efficiently through the targeting effect of transporters. At present， more and more evidences supported the potential of transporters in the field of oral drug delivery system. Therefore， this paper reviewed the research on intestinal transporters-mediated nano-delivery system to promote oral absorption of drugs， including the distribution of intestinal transporters， three strategies of transporter substrate modification， the transport properties of different types of transporters and their effects of mediating the nano-delivery system for promoting the oral absorption of drugs or treating diseases， with the aim of providing an important theoretical reference for the development of intestinal targeted nano-delivery systems.

Arctium lappa L. roots inhibit the intestinal inflammation of dietary obese rats through TLR4/NF-κB pathway.

Long-term consumption of Arctium lappa L. roots can lead to weight loss. To explore the relationship between anti-obesity and anti-inflammation, the effects and mechanism of A. lappa L. root powder (ARP) on intestinal inflammation in obese rats were investigated. Dietary obese rats were successfully established by feeding a high-fat and high-sugar diet. The control group (n = 6) consumed a normal diet. The intestines were compared among the groups (each n = 6) with and without the administration of ARP (intragastric 7.5 g/kg·bw/d). Real-time quantitative reverse transcription-polymerase chain reaction and western blotting analysis revealed that ARP effectively inhibited the expression of pro-inflammatory and inflammatory cytokines in the colons of obese rats. These cytokines included interleukin (IL)-1ß, IL-8, IL-6, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1. The inhibition rates for all these cytokines exceeded 88 %. Moreover, ARP demonstrated the ability to down-regulate key genes involved in Toll-like receptor 4 (TLR4) complexes, namely Tlr4, myeloid differentiation protein-2 (Md2), and myeloid differentiation factor 88 (Myd88), along with downstream signaling molecules such as tumor necrosis factor receptor associated factor 6 (TRAF6) and nuclear factor-κB (NF-κB), with inhibition rates over 81 %. Additionally, ARP was observed to inhibit protein levels of TLR4, NF-κB, IL-1ß, and TNF-α in the colons of obese rats, with inhibition rates of 65.6 ± 10.9 %, 84.4 ± 19.9 %, 80.8 ± 14.4 %, and 68.4 ± 17.5 %, respectively. This study confirmed the effectiveness of ARP in inhibiting intestinal inflammation through the blockade of the TLR4/NF-κB signaling pathway. It also suggested that ARP holds potential in improving intestinal health in the context of obesity, implying its possible application in the prevention and treatment of obesity and related metabolic diseases.

[Analysis and Modeling of Risk Factors for Children with Intestinal Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To analyze factors associated with intestinal acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation(allo-HSCT) in children and to develop a prediction model for intestinal aGVHD after allo-HSCT in children. METHODS: The clinical data of 62 children who underwent allo-HSCT at the Department of Hematology of the People's Hospital of Xinjiang Uygur Autonomous Region from February 2018 to September 2021 were retrospectively analyzed. Intestinal aGVHD was evaluated according to the Mount Sinai Acute GVHD International Consortium (MAGIC) grading criteria, the variables were screened by LASSO (least absolute shrinkage and selection operator) regression analysis with 10-fold cross-validation, and developed a model for predicting intestinal aGVHD after allo-HSCT in children. RESULTS: A total of 33 (53.2%) of the 62 children developed intestinal aGVHD, of which 25 were degree II and 8 were degree III-IV. The results of screening variables by 10-fold cross-validated LASSO regression showed that the significant variables included ethnic minorities (OR =7.229; 95%CI: 2.337-22.354), platelet (PLT) (OR =0.971; 95%CI: 0.932-0.993), uric acid (UA) (OR =0.971; 95%CI: 0.935-0.988), C-reactive protein (CRP) (OR =1.217; 95%CI: 1.053-1.545), and viral infection (OR =10; 95%CI: 3.021-32.668), and these variables were independently associated with intestinal aGVHD in children (all P <0.05). A prediction model was constructed based on above variables. The area under the receiver operating characteristic (ROC) curve (AUC) of the model was calculated, and the AUC value was 0.985 (0.966-1), the Brier score was 0.055. The evaluation showed that the model has a high degree of discrimination and calibration. CONCLUSION: Ethnic minorities, low PLT, low UA, high CRP, and viral infections are independently associated with intestinal aGVHD in children, and early attention should be paid to these high-risk children.

Archaeome structure and function of the intestinal tract in healthy and H1N1 infected swine.

Background: Methanogenic archaea represent a less investigated and likely underestimated part of the intestinal tract microbiome in swine. Aims/Methods: This study aims to elucidate the archaeome structure and function in the porcine intestinal tract of healthy and H1N1 infected swine. We performed multi-omics analysis consisting of 16S rRNA gene profiling, metatranscriptomics and metaproteomics. Results and discussion: We observed a significant increase from 0.48 to 4.50% of archaea in the intestinal tract microbiome along the ileum and colon, dominated by genera Methanobrevibacter and Methanosphaera. Furthermore, in feces of naïve and H1N1 infected swine, we observed significant but minor differences in the occurrence of archaeal phylotypes over the course of an infection experiment. Metatranscriptomic analysis of archaeal mRNAs revealed the major methanogenesis pathways of Methanobrevibacter and Methanosphaera to be hydrogenotrophic and methyl-reducing, respectively. Metaproteomics of archaeal peptides indicated some effects of the H1N1 infection on central metabolism of the gut archaea. Conclusions/Take home message: Finally, this study provides the first multi-omics analysis and high-resolution insights into the structure and function of the porcine intestinal tract archaeome during a non-lethal Influenza A virus infection of the respiratory tract, demonstrating significant alterations in archaeal community composition and central metabolic functions.

Preparation of chitosan-coated hollow tin dioxide nanoparticles and their application in improving the oral bioavailability of febuxostat.

The aim of this study was to design a chitosan-coated hollow tin dioxide nanosphere (CS-HSn) for loading febuxostat (FEB) using an adsorption method to obtain a sustained-release system (CS-HSn-FEB) to improve the oral bioavailability of FEB. The morphological characteristics of hollow tin dioxide nanospheres (HSn) and CS-HSn were analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The hemolysis test and CCK-8 test were used to assess the biosafety of HSn and CS-HSn. Powder X-ray diffraction (PXRD) and differential scanning thermal analysis (DSC) were performed on CS-HSn-FEB to analyze the drug presence status. The dissolution behavior and changes in plasma drug concentration of CS-HSn-FEB were evaluated in vitro and in vivo. Sections of intestinal tissues from SD rats were obtained to observe whether chitosan could increase the distribution of nanoparticles in the intestinal tissues. The results showed that FEB was present in CS-HSn in an amorphous state. Moreover, CS-HSn, with good biosafety, significantly improved the water solubility and oral absorption of FEB, indicating that CS-HSn has great potential to improve the intestinal absorption and oral bioavailability of insoluble drugs.

The Gastrointestinal Tract Is Pinpointed as a Reservoir of Candida albicans, Candida parapsilosis, and Candida tropicalis Genotypes Found in Blood and Intra-Abdominal Samples.

BACKGROUND: Candida spp., as part of the microbiota, can colonise the gastrointestinal tract. We hypothesised that genotyping Candida spp. isolates from the gastrointestinal tract could help spot genotypes able to cause invasive infections. MATERIALS/METHODS: A total of 816 isolates of C. albicans (n = 595), C. parapsilosis (n = 118), and C. tropicalis (n = 103) from rectal swabs (n = 754 patients) were studied. Genotyping was conducted using species-specific microsatellite markers. Rectal swab genotypes were compared with previously studied blood (n = 814) and intra-abdominal (n = 202) genotypes. RESULTS: A total of 36/754 patients had the same Candida spp. isolated from blood cultures, intra-abdominal samples, or both; these patients had candidemia (n = 18), intra-abdominal candidiasis (n = 11), both clinical forms (n = 1), and non-significant isolation (n = 6). Genotypes matching the rectal swab and their blood cultures (84.2%) or their intra-abdominal samples (92.3%) were found in most of the significant patients. We detected 656 genotypes from rectal swabs, 88.4% of which were singletons and 11.6% were clusters. Of these 656 rectal swab genotypes, 94 (14.3%) were also detected in blood cultures and 34 (5.2%) in intra-abdominal samples. Of the rectal swab clusters, 62.7% were previously defined as a widespread genotype. CONCLUSIONS: Our study pinpoints the gastrointestinal tract as a potential reservoir of potentially invasive Candida spp. genotypes.

Effects of dosing non-toxigenic Clostridia on the bacterial populations and immunological responses in the intestinal tract of lactating dairy cows.

Understanding the effects of dosing non-toxigenic Clostridia to cows is rare and has received little attention so far. In the present study, a total of eight lactating dairy cows were divided in two groups: control (n = 4) or Clostridia challenged (oral supplementation of five diverse strains of Paraclostridium bifermentans, n = 4). Bacterial communities were analyzed by qPCR and next-generation sequencing (NGS) in the buccal mucosa as well as digesta and mucosal samples of the gastrointestinal (GI) tract from rumen to rectum (10 compartments), as well as fecal samples. Transcriptomic analysis of barrier and immune-related gene expression was performed on rumen, jejunum, and liver samples. We observed increased microbial populations with the Clostridial challenge in the buccal tissues and the proximal GI tract (forestomach), correlating with Clostridial loads in the feed. Otherwise, there were no significant differences in microbial populations (p > 0.05) throughout the distal part of the GI tract. The NGS approach, however, revealed that the Clostridial challenge changed the relative abundance of gut and fecal microbiota. In particular, in the challenge group, no Bifidobacterium was observed in the mucosa-associated microbiota and abundance of Pseudomonadota increased in the feces. These results indicated potential adverse effects of Clostridia to cow health. In general, immune responses to the Clostridial challenge were weak. However, transcriptional analysis revealed the down-regulation of junction adhesion molecule encoding gene (-1.44 of log2 fold-change), which might impact intestinal permeability.

Nothobranchius as a model for anorexia of aging research: an evolutionary, anatomical, histological, immunohistochemical, and molecular study.

BACKGROUND: Anorexia of aging, defined as a decrease in appetite and a preponderant loss of body weight occurring in late life, is one of the most common diseases affecting older people. The peptide hormone cholecystokinin (Cck) is known to play a key role in regulating food intake and satiety in higher vertebrates. In humans as well as in rats, an increased concentration of Cck was described as the basis of appetite loss in elderly. However, the role of increased plasma Cck concentrations in mediating the age-related decrease in appetite remains to be established. Although in vitro studies are an excellent resource for investigating aging, the use of a model organism that shares and imitates the human physiological processes guarantees a better understanding of the in vivo mechanisms. African annual fishes from the genus Nothobranchius are emerging as a prominent model organism in biogerontology and developmental biology due to their short captive lifespan. Therefore, in the current study, we aimed to investigate the possibility of using the genus Nothobranchius to model the anorexia of aging and their potential contribution to better understanding the pathway by which Cck induce appetite loss in older people providing a comparative/evolutionary localization of the current study model among the aging canonicals models, the morphology of its gastrointestinal tract and its Cck expression pattern. METHODS: The comparative/evolutionary investigation was conducted using the NCBI blastp (protein-protein BLAST) and NCBI Tree Viewer. The macroscopic morphology, histological features, ultrastructural organization of Nothobranchius rachovii gastrointestinal tract were investigated using stereomicroscope, Masson's trichrome and alcian blue-PAS staining, and transmission electron microscopy, respectively. The cck expression pattern was studied through immunofluorescence labeling, western blotting, and quantitative RT-PCR. RESULTS: The intestine was folded into different segments divided into an anterior intestine made of a rostral intestinal bulb and an intestinal annex of lower diameter, mid and posterior intestine. The gradual transition from the rostral intestinal bulb to the posterior intestine sections's epithelium is characterized by a gradual reduction in the striated muscular bundles, villi height, and goblet mucous cells count. The lining epithelium of the intestinal villi was characterized by a typical brush border enterocytes full of mitochondria. Moreover, Cck expression was detected in scattered intraepithelial cells concentrated in the anterior tract of the intestine. CONCLUSIONS: Our study introduces Nothobranchius rachovii as a model for anorexia of aging, giving the first bases on the gastrointestinal tract morphology and cck expression pattern. Future studies on young and elderly Notobranchius can divulge the contribution of cck in the mechanisms of anorexia associated with aging.

Short-Term Alternate Feeding between Terrestrially Sourced Oil- and Fish Oil-Based Diets Modulates the Intestinal Microecology of Juvenile Turbot.

A nine-week feeding trial was conducted to investigate changes in the intestinal microbiota of turbot in response to alternate feeding between terrestrially sourced oil (TSO)- and fish oil (FO)-based diets. The following three feeding strategies were designed: (1) continuous feeding with the FO-based diet (FO group); (2) weekly alternate feeding between soybean oil (SO)- and FO-based diets (SO/FO group); and (3) weekly alternate feeding between beef tallow (BT)- and FO-based diets (BT/FO group). An intestinal bacterial community analysis showed that alternate feeding reshaped the intestinal microbial composition. Higher species richness and diversity of the intestinal microbiota were observed in the alternate-feeding groups. A PCoA analysis showed that the samples clustered separately according to the feeding strategy, and among the three groups, the SO/FO group clustered relatively closer to the BT/FO group. The alternate feeding significantly decreased the abundance of Mycoplasma and selectively enriched specific microorganisms, including short-chain fatty acid (SCFA)-producing bacteria, digestive bacteria (Corynebacterium and Sphingomonas), and several potential pathogens (Desulfovibrio and Mycobacterium). Alternate feeding may maintain the intestinal microbiota balance by improving the connectivity of the ecological network and increasing the competitive interactions within the ecological network. The alternate feeding significantly upregulated the KEGG pathways of fatty acid and lipid metabolism, glycan biosynthesis, and amino acid metabolism in the intestinal microbiota. Meanwhile, the upregulation of the KEGG pathway of lipopolysaccharide biosynthesis indicates a potential risk for intestinal health. In conclusion, short-term alternate feeding between dietary lipid sources reshapes the intestinal microecology of the juvenile turbot, possibly resulting in both positive and negative effects.

Localisation and identification of polystyrene particles in tissue sections using Raman spectroscopic imaging.

The uptake of microplastic particles (MPP) by organisms is frequently described and poses a potential risk for these organisms and ultimately for humans either through direct uptake or trophic transfer. Currently, the in-situ detection of MPP in organisms is typically based on histological examination of tissue sections after uptake of fluorescently-labelled MPP and is thus not feasible for environmental samples. The alternative approach is purification of MPP from whole organisms or organs by chemical digestion and subsequent spectroscopic detection (FT-IR or Raman). While this approach is feasible for un-labelled particles it goes along with loss of any spatial information related to the location in the tissue. In our study we aimed at providing a workflow for the localisation and identification of non-fluorescent and fluorescent polystyrene (PS) particles (fragments, size range 2-130 µm) in tissue sections of the model organism Eisenia fetida with Raman spectroscopic imaging (RSI). We provide methodological approaches for the preparation of the samples, technical parameters for the RSI measurements and data analysis for PS differentiation in tissue sections. The developed approaches were combined in a workflow for the in-situ analysis of MPP in tissue sections. The spectroscopic analysis requires differentiation of spectra of MPP and interfering compounds, which is challenging given the complexity of tissue. Therefore, a classification algorithm was developed to differentiate PS particles from haem, intestinal contents and surrounding tissue. It allows the differentiation of PS particles from protein in the tissue of E. fetida with an accuracy of 95%. The smallest PS particle detected in the tissue was 2 µm in diameter. We show that it is possible to localise and identify non-fluorescent and fluorescent ingested PS particles directly in tissue sections of E. fetida in the gut lumen and the adjacent tissue.

Comparison study of protective effects of porcine bile acids and sheep bile acids against heat stress in chickens.

BACKGROUND: Heat stress (HS) is known to exert negative effects on the poultry and breeding industry, resulting in severe economic losses. Bile acids (BAs), an important component of bile, play a crucial role in improving the production performance of livestock and poultry, alleviating stress injury, and ensuring the health of livestock and poultry. At present, porcine BAs are widely used because of their therapeutic effects on HS; however, it remains unclear whether the same effects are exerted by sheep BAs, which are different from porcine BAs and have different compositions. In this study, we compared the anti-HS effects of porcine BAs and sheep BAs in the diet by establishing an HS model of chicks and investigating the chicken performance, HS-related genes' expression, oxidative stress markers, jejunal histoarchitecture, inflammatory cytokines' expression, jejunal secreted immunoglobulin A concentration, and cecal bacterial flora. RESULTS: The results showed that the addition of sheep BAs to the diet increased the average daily weight gain and the feed conversion ratio of chicks. Under HS, sheep BAs were more effective than porcine BAs in improving the activities of lactate dehydrogenase and glutamic pyruvic transaminase in serum and the content/activity of malondialdehyde, superoxide dismutase, and reduced glutathione in serum and tissue, in reducing the messenger RNA (mRNA) expression of heat shock proteins (HSP60, HSP70, and HSP90) in the liver and jejunum, and in improving the histological structure and the expression of tight junction proteins (occludin and zonula occludens-1) and enriching intestinal bacterial flora. However, porcine BAs were significantly inferior to sheep BAs in reducing the mRNA expression of inflammatory factors (interleukin-6, interleukin-1ß, and tumor necrosis factor-α). CONCLUSION: The effect of sheep BAs was more significant than porcine BAs was in alleviating HS injury in chicks, suggesting that sheep BAs have great potential as new feed nutrition and health additive to improve poultry production performance and prevent HS. © 2023 Society of Chemical Industry.

Maribacter litopenaei sp. nov., isolated from the intestinal tract of the Pacific white shrimp Litopenaeus vannamei.

A Gram-stain-negative, aerobic, rod-shaped bacterial strain, designated HL-LV01T, was isolated from the intestinal tract content of the Pacific white shrimp Litopenaeus vannamei. The 16S rRNA gene sequence of strain HL-LV01T showed that the strain was clearly a member of the genus Maribacter. According to the phylogenetic analyses, strain HL-LV01T was most closely related to the species Maribacter flavus KCTC 42508T with 98.2 % sequence similarity. The average nucleotide identity and digital DNA-DNA hybridization values between strain HL-LV01T and M. flavus KCTC 42508T were 80.6 % and 23.0 %, respectively, indicating different genomic species in the genus Maribacter. Strain HL-LV01T showed optimal growth at 35 °C, pH 7.0, and 2.5 % (w/v) sea salts. The major cellular fatty acids were iso-C15 : 0 (32.5 %), iso-C17 : 0 3-OH (22.3 %), and iso-C15 : 1 G (15.5 %). The major respiratory quinone was menaquinone-6. The polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids, and seven unidentified lipids. The genomic DNA G+C content of the strain was 39.8 mol%. The comprehensive phylogenetic, genomic, phenotypic, and chemotaxonomic results indicate that strain HL-LV01T is distinct from validly published species of the genus Maribacter. Hence, we propose strain HL-LV01T as a novel species belonging to the genus Maribacter, for which the name Maribacter litopenaei sp. nov. is proposed. The type strain is HL-LV01T (= KCCM 90498T = JCM 35709T).

The potential role of molecular mimicry by the anaerobic microbiota in the aetiology of autoimmune disease.

Autoimmune diseases are thought to develop as a consequence of various environmental and genetic factors, each of which contributes to dysfunctional immune responses and/or a breakdown in immunological tolerance towards native structures. Molecular mimicry by microbial components is among the environmental factors thought to promote a breakdown in immune tolerance, particularly through the presence of cross-reactive epitopes shared with the human host. While resident members of the microbiota are essential promoters of human health through immunomodulation, defence against pathogenic colonisation and conversion of dietary fibre into nutritional resources for host tissues, there may be an underappreciated role of these microbes in the aetiology and/or progression of autoimmune disease. An increasing number of molecular mimics are being identified amongst the anaerobic microbiota which structurally resemble endogenous components and, in some cases, for example the human ubiquitin mimic of Bacteroides fragilis and DNA methyltransferase of Roseburia intestinalis, have been associated with promoting antibody profiles characteristic of autoimmune diseases. The persistent exposure of molecular mimics from the microbiota to the human immune system is likely to be involved in autoantibody production that contributes to the pathologies associated with immune-mediated inflammatory disorders. Here-in, examples of molecular mimics that have been identified among resident members of the human microbiota and their ability to induce autoimmune disease through cross-reactive autoantibody production are discussed. Improved awareness of the molecular mimics that exist among human colonisers will help elucidate the mechanisms involved in the breakdown of immune tolerance that ultimately lead to chronic inflammation and downstream disease.

Citrus limon phytocompounds decorated nanoparticles control poultry pathogens.

Antibiotic resistance poses a significant threat to the global health, food security, and environment. In poultry and livestock, antibiotics are beneficial since they improve poultry performance and are economically effective. Therefore, it is crucial to search for alternatives that can be environmentally safe and successful in treating these infections. In this study, we employed molecular docking to evaluate lemon peel phytochemical's protein binding capability against various poultry pathogens. The nanoparticles (LP AgNPs) obtained from the lemon peel were characterized and tested for their antibacterial activity against more poultry pathogens. LP AgNPs were characterized by using UV-Visible absorption spectra, which revealed an absorption peak at a wavelength of 420-440 nm. The FT-IR analysis demonstrated that flavonoids and phenolic acids acted as capping, reducing, and stabilizing agents during the biosynthesis of AgNPs. EDAX showed a strong peak was observed at 3 keV which revealed the absorption of metallic silver nanoparticles. The mean diameter was from 2 to 20 nm through HRTEM. Zeta potential of the LP AgNps at - 17.2 mV showed the high stability of the green synthesized AgNps. Maximum inhibitory concentrations of LP AgNps against the isolated poultry pathogens were 50 µg/ml concentration. The toxicity tests were performed in the Vigna radiata seedlings and Artemia nauplii, which showed less toxic effects and eco-friendly nature of the LP AgNps. LP AgNps have the potential to treat antibiotic resistant poultry pathogens, thereby paving the way for the development of value-added novel products incorporated with nanoparticles for treating various infection caused by antibiotic-resistant poultry pathogens.

Prevalence and molecular characteristics of community-associated methicillin-resistant Staphylococcus aureus in the respiratory tracts of Chinese adults with community-acquired pneumonia.

BACKGROUND: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is an important pathogen causing healthcare-associated infections. In recent years, an increasing number of CA-MRSA clones have emerged and rapidly spread in the community and hospital settings in China. OBJECTIVES: To investigate the molecular epidemiology and resistance of CA-MRSA in the respiratory tracts of Chinese adults with community-acquired pneumonia (CAP). METHODS: A total of 243 sputum samples were collected from adult patients with CAP at the Nantong Hospital in China between 2018 and 2021. S. aureus was identified using PCR, and its susceptibility to 14 antimicrobials was tested using the broth dilution method. Genomic characterization of respiratory CA-MRSA and our previously collected intestinal CA-MRSA isolates was performed using whole-genome sequencing, and the evolutionary relationships of these isolates were assessed using phylogenetic analysis. RESULTS: The CA-MRSA colonization rate among adults with CAP in China was 7.8 % (19/243). Antimicrobial resistance analysis revealed that the proportion of multidrug-resistant respiratory CA-MRSA isolates (100 %) was higher than that of intestinal CA-MRSA isolates (6.3 %). Among the 35 CA-MRSA isolates, 10 MLST types were identified and clustered into five clone complexes (CCs). CC5 (48.6 %) and CC88 (20 %) were predominant CA-MRSA clones. Notably, the CC5 clone ST764/ST6292-MRSA-II-t002 was identified as the major lineage causing respiratory tract infections in Chinese adults with CAP. CONCLUSIONS: The prevalence of CA-MRSA among Chinese adults with CAP is high and often involves ST764/ST6292-MRSA-II-t002 as the causal pathogen.

Comparative analysis of two nonlethal methods for the study of the gut bacterial communities in wild lizards.

Fecal samples or cloacal swabs are preferred over lethal dissections to study vertebrate gut microbiota for ethical reasons, but it remains unclear which nonlethal methods provide more accurate information about gut microbiota. We compared the bacterial communities of three gastrointestinal tract (GIT) segments, that is, stomach, small intestine (midgut), and rectum (hindgut) with the bacterial communities of the cloaca and feces in the mesquite lizard Sceloporus grammicus. The hindgut had the highest taxonomic and functional alpha diversity, followed by midgut and feces, whereas the stomach and cloaca showed the lowest diversities. The taxonomic assemblages of the GIT segments at the phylum level were strongly correlated with those retrieved from feces and cloacal swabs (rs > 0.84 in all cases). The turnover ratio of Amplicon Sequence Variants (ASVs) between midgut and hindgut and the feces was lower than the ratio between these segments and the cloaca. More than half of the core-ASVs in the midgut (24 of 32) and hindgut (58 of 97) were also found in feces, while less than 5 were found in the cloaca. At the ASVs level, however, the structure of the bacterial communities of the midgut and hindgut were similar to those detected in feces and cloaca. Our findings suggest that fecal samples and cloacal swabs of spiny lizards provide a good approximation of the taxonomic assemblages and beta diversity of midgut and hindgut microbiota, while feces better represent the bacterial communities of the intestinal segments at a single nucleotide variation level than cloacal swabs.

Orchestration of MUC2 - The key regulatory target of gut barrier and homeostasis: A review.

The gut mucosa of human is covered by mucus, functioning as a crucial defense line for the intestine against external stimuli and pathogens. Mucin2 (MUC2) is a subtype of secretory mucins generated by goblet cells and is the major macromolecular component of mucus. Currently, there is an increasing interest on the investigations of MUC2, noting that its function is far beyond a maintainer of the mucus barrier. Moreover, numerous gut diseases are associated with dysregulated MUC2 production. Appropriate production level of MUC2 and mucus contributes to gut barrier function and homeostasis. The production of MUC2 is regulated by a series of physiological processes, which are orchestrated by various bioactive molecules, signaling pathways and gut microbiota, etc., forming a complex regulatory network. Incorporating the latest findings, this review provided a comprehensive summary of MUC2, including its structure, significance and secretory process. Furthermore, we also summarized the molecular mechanisms of the regulation of MUC2 production aiming to provide developmental directions for future researches on MUC2, which can act as a potential prognostic indicator and targeted therapeutic manipulation for diseases. Collectively, we elucidated the micro-level mechanisms underlying MUC2-related phenotypes, hoping to offer some constructive guidance for intestinal and overall health of mankind.