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Virulence Dec 2023spp. are the causative agent of shigellosis (or bacillary dysentery), a diarrhoeal disease characterized for the bacterial invasion of gut epithelial cells. Among the 4... (Review)
Review
spp. are the causative agent of shigellosis (or bacillary dysentery), a diarrhoeal disease characterized for the bacterial invasion of gut epithelial cells. Among the 4 species included in the genus, is principally responsible for the disease in the developing world while is the main causative agent in high-income countries. Remarkably, as more countries improve their socioeconomic conditions, we observe an increase in the relative prevalence of . To date, the reasons behind this change in aetiology depending on economic growth are not understood. has been widely used as a model to study the pathogenesis of the genus, but as more research data are collected, important discrepancies with have come to light. In comparison to can be differentiated in numerous aspects; it presents a characteristic O-antigen identical to that of one serogroup of the environmental bacterium , a group 4 capsule, antibacterial mechanisms to outcompete and displace gut commensal bacteria, and a poorer adaptation to an intracellular lifestyle. In addition, the World Health Organization (WHO) have recognized the significant threat posed by antibiotic-resistant strains of , demanding new approaches. This review gathers knowledge on what is known about within the context of other spp. and aims to open the door for future research on understanding the increasing spread of this pathogen.
Topics: Humans; Shigella sonnei; Virulence; Prevalence; Anti-Bacterial Agents; Cell Differentiation; Dysentery, Bacillary
PubMed: 37994877
DOI: 10.1080/21505594.2023.2280838 -
International Journal of Molecular... Sep 2023The pyruvate dehydrogenase complex regulator (PdhR) was originally identified as a repressor of the operon, which encodes the pyruvate dehydrogenase complex (PDHc) and...
The pyruvate dehydrogenase complex regulator (PdhR) was originally identified as a repressor of the operon, which encodes the pyruvate dehydrogenase complex (PDHc) and PdhR itself. According to previous reports, PdhR plays a regulatory role in the physiological and metabolic pathways of bacteria. At present, the function of PdhR in is still poorly understood. In this study, RNA sequencing (RNA-Seq) of the wild-type strain and the Δ mutant strains was performed for comparison to identify the PdhR-controlled pathways, revealing that PdhR regulates ~7.38% of the transcriptome. We found that the deletion of resulted in the downregulation of practically all polar and lateral flagella genes in ; meanwhile, motility assay and transmission electron microscopy (TEM) confirmed that the Δ mutant was non-motile and lacked flagella. Moreover, the results of RNA-seq and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) showed that PdhR positively regulated the expression of the T3SS cluster, and the Δ mutant significantly reduced the ability of to infect Caco-2 cells compared with the WT. Consistent with previous research, pyruvate-sensing PdhR directly binds to its promoter and inhibits -- operon expression. In addition, we identified two additional downstream genes, and , that are directly negatively regulated by PdhR. Furthermore, we also demonstrated that ArcA was identified as being located upstream of and and directly negatively regulating their expression. Overall, we revealed the function and regulatory pathway of PdhR, which will allow for a more in-depth investigation into pathogenicity as well as the complex regulatory network.
Topics: Humans; Pyruvate Dehydrogenase Complex; Escherichia coli Proteins; Plesiomonas; Escherichia coli; Repressor Proteins; Caco-2 Cells; Gene Expression Profiling
PubMed: 37833920
DOI: 10.3390/ijms241914473 -
Aquaculture Nutrition 2023Citric acid is an organic acid extensively used in feed industry, and AZOMITE is a hydrated aluminosilicate compound rich in rare earth elements and trace mineral...
Citric acid is an organic acid extensively used in feed industry, and AZOMITE is a hydrated aluminosilicate compound rich in rare earth elements and trace mineral elements. This study investigated the supplemental effects of AZOMITE and citric acid individual or in combination on the growth performance, intestinal microbiota, morphology, digestive enzyme activity, serum indexes, and disease resistance of juvenile largemouth bass. Six diets were designed, including the control diet (CON) and the five additive-supplemented diets with the addition of 4 or 8 g/kg citric acid (CA4, CA8), 3 g/kg AZOMITE (A3), and their combined addition as 4 g/kg citric acid + 1.5 g/kg AZOMITE) (C4A1.5) and 8 g/kg citric acid + 3 g/kg AZOMITE (C8A3). Juvenile largemouth bass with initial body weight of 22.01 ± 0.09 g were fed the six diets for 56 days. The results revealed that the combined addition of 4 g/kg citric acid and 1.5 g/kg AZOMITE (C4A1.5) increased weight gain by 7.99% ( < 0.05), and decreased feed conversion ratio by 0.07 ( < 0.05). The protein retention in the C4A1.5 group and the lipid retention in all additive-supplemented groups were significantly higher than those in the control group ( < 0.05). In serum, all additive-supplemented groups showed significantly higher glutathione peroxidase activity than the control group ( < 0.05). The activities of superoxide dismutase and catalase in the CA8, A3, C4A1.5, and C8A3 groups were significantly higher ( < 0.05), while the concentration of malondialdehyde was significantly lower than those in the control group ( < 0.05). Moreover, the total antioxidant capacity in the A3 and C4A1.5 groups, and lysozyme activity in the A3, C4A1.5, and C8A3 groups were significantly increased when compared to the control group ( < 0.05). In digestive enzyme, the protease activity in the A3, C4A1.5 groups, and amylase activity in the CA4, CA8, and C4A1.5 groups were significantly higher than those in the control group ( < 0.05). In intestinal microbiota, abundance was elevated in all additive groups, while the and abundance were decreased. In the intestinal histology, the CA8, A3, and C4A1.5 groups showed significantly higher villus height than the control group ( < 0.05). After the infection with , the cumulative mortality of all additive-supplemented groups was significantly lower ( < 0.05), and the C4A1.5 group demonstrated the lowest mortality. In conclusion, the combined supplementation of 4 g/kg citric acid + 1.5 g/kg AZOMITE increased the growth, antioxidant, immune capacity, improved the intestinal morphology and microbial flora of juvenile largemouth bass, and promoted the resistance against infection.
PubMed: 37881475
DOI: 10.1155/2023/5022456 -
Microbiology Spectrum Jun 2023Poplar anthracnose caused by Colletotrichum gloeosporioides is a common disease affecting poplars globally that causes the destruction and alteration of poplar...
Poplar anthracnose caused by Colletotrichum gloeosporioides is a common disease affecting poplars globally that causes the destruction and alteration of poplar phyllosphere microbial communities; however, few studies have investigated these communities. Therefore, in this study, three species of poplar with different resistances were investigated to explore the effects of and poplar secondary metabolites on the composition of poplar phyllosphere microbial communities. Evaluation of the phyllosphere microbial communities before and after inoculation of the poplars with revealed that both bacterial and fungal OTUs decreased after inoculation. Among bacteria, the most abundant genera were , , Pseudomonas, , , Streptococcus, , and for all poplar species. Among fungi, the most abundant genera before inoculation were , Aspergillus, Fusarium, , and , while was the main genus after inoculation. The inoculation of pathogens may regulate the phyllosphere microorganisms by affecting the secondary metabolites of plants. We investigated metabolite contents in the phyllosphere before and after the inoculation of the three poplar species, as well as the effects of flavonoids, organic acids, coumarins, and indoles on poplar phyllosphere microbial communities. We speculated that coumarin had the greatest recruitment effect on phyllosphere microorganisms, followed by organic acids through regression analysis. Overall, our results provide a foundation for subsequent screening of antagonistic bacteria and fungi against poplar anthracnose and investigations of the mechanism by which poplar phyllosphere microorganisms are recruited. Our findings revealed that the inoculation of has a greater effect on the fungal community than the bacterial community. In addition, coumarins, organic acids, and flavonoids may have recruitment effects on phyllosphere microorganisms, while indoles may have inhibitory effects on these organisms. These findings may provide the theoretical basis for the prevention and control of poplar anthracnose.
Topics: Colletotrichum; Bacteria; Bacillus; Microbiota; Plant Diseases
PubMed: 37219434
DOI: 10.1128/spectrum.04603-22 -
European Journal of Medical Research Sep 2023Gallstone disease is a prevalent biliary disease worldwide, and bacteria play vital roles in the disease development and progression, as well as the prognosis after...
Gallstone disease is a prevalent biliary disease worldwide, and bacteria play vital roles in the disease development and progression, as well as the prognosis after endoscopic surgery. However, there have been limited studies to explore the key taxa involved. In this study, bile samples from healthy controls (HCs, liver donors without hepatobiliary disease) and three diseased groups, namely patients with gallbladder stones (GBS), patients with common bile duct stones (CBDS), and patients with stricture in the common bile duct (SCBD), were collected and analyzed. Bacterial community characterization based on 16S rRNA amplicon sequencing showed that bacterial diversities did not change significantly alongside gallstone disease development and progression. The predominant phyla in each group were Proteobacteria, Firmicutes, Bacteroidota, and Fusobacteriota, representing over 80% in abundance of the biliary bacteria community. Specifically, the abundance of Proteobacteria decreased greatly while that of Firmicutes and Bacteroidota increased greatly in the diseased groups when compared to that in HCs. Moreover, linear discriminant analysis identified several genera highly represented in the diseased groups. Among them, Klebsiella, Prevotella, Pseudomonas and Veillonella are persistent in both the HCs group and the diseased groups, indicating an enrichment of local bile bacteria in the diseased bile; while Lachnoanerobaculum, Atopobium, Oribacterium, and Stomatobaculum, those aligned to oral cavity taxa, are persistent in the diseased groups but are transient in the HCs group, and their abundances sequentially increased with the disease development and progression (HCs→GBS→CBDS→SCBD), implying a translocation and colonization of the oral cavity bacteria in the diseased bile. Moreover, co-occurrence network analysis revealed that bacterial infection (e.g., Photobacterium and Plesiomonas) from the intestine was developed during endoscopic surgery with reduced bile bacteria diversity. The results of this study revealed that the bile bacterial community is relatively stable and dominated by a few persistent taxa. Moreover, we hypothesized that translocation and colonization of specific bacteria from the oral cavity happens alongside gallstone disease development and progression, and bacterial infection from the intestinal tract results in poor outcomes after endoscopic surgery.
Topics: Humans; Gallstones; Bile; RNA, Ribosomal, 16S; Bacteria; Constriction, Pathologic; Disease Progression
PubMed: 37660138
DOI: 10.1186/s40001-023-01308-y -
Drug Design, Development and Therapy 2024Willd. (PT), a traditional Chinese medicinal plant extensively employed in managing Alzheimer's disease, exhibits notable gastrointestinal side effects as highlighted...
Magnolia Officinalis Alcohol Extract Alleviates the Intestinal Injury Induced by Polygala Tenuifolia Through Regulating the PI3K/AKT/NF-κB Signaling Pathway and Intestinal Flora.
PURPOSE
Willd. (PT), a traditional Chinese medicinal plant extensively employed in managing Alzheimer's disease, exhibits notable gastrointestinal side effects as highlighted by prior investigations. In contrast, Rehd. et Wils (MO), a traditional remedy for gastrointestinal ailments, shows promising potential for ameliorating this adverse effect of PT. The objective of this study is to examine the underlying mechanism of MO in alleviating the side effects of PT.
METHODS
Hematoxylin-eosin (H&E) staining was used to observe the structural damage of zebrafish intestine, and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors and oxidative stress. The integrity of the intestinal tight junctions was examined using transmission electron microscope (TEM). Moreover, the expression of intestinal barrier genes and PI3K/AKT/NF-κB signaling pathway-related genes was determined through quantitative real-time PCR. The changes in intestinal microbial composition were analyzed using 16S rRNA and metagenomic techniques.
RESULTS
MO effectively ameliorated intestinal pathological damage and barrier gene expression, and significantly alleviated intestinal injury by reducing the expression of inflammatory cytokines IL-1β, IL-6, TNF-α, and inhibiting the activation of PI3K/AKT/NF-κB pathway. Furthermore, MO could significantly increase the relative abundance of beneficial microorganisms ( and ), and reduce the relative abundance of pathogenic bacteria ( and ).
CONCLUSION
MO alleviated PT-induced intestinal injury, and its mechanism may be related to the inhibition of PI3K/AKT/NF-κB pathway activation and regulation of intestinal flora.
Topics: Magnolia; Polygala; Animals; Gastrointestinal Microbiome; NF-kappa B; Signal Transduction; Proto-Oncogene Proteins c-akt; Phosphatidylinositol 3-Kinases; Zebrafish; Plant Extracts; Intestines
PubMed: 38799799
DOI: 10.2147/DDDT.S461152 -
Antioxidants (Basel, Switzerland) Dec 2023A 10-week growth experiment was conducted to assess the physiological response of spotted seabass () raised at moderate (27 °C) and high temperatures (33 °C) to...
Physiological Response of Spotted Seabass () to Different Dietary Available Phosphorus Levels and Water Temperature: Changes in Growth, Lipid Metabolism, Antioxidant Status and Intestinal Microbiota.
A 10-week growth experiment was conducted to assess the physiological response of spotted seabass () raised at moderate (27 °C) and high temperatures (33 °C) to different dietary available phosphorus (P) levels. Five diets with available P levels of 0.35, 0.55, 0.71, 0.82 and 0.92% were formulated, respectively. A water temperature of 33 °C significantly decreased growth performance and feed utilization, and increased oxidative stress and lipid deposition of spotted seabass compared with 27 °C. A second-order polynomial regression analysis based on weight gain (WG) showed that the available P requirement of spotted seabass raised at 27 °C and 33 °C was 0.72% and 0.78%, respectively. The addition of 0.71-0.82% P to the diet improved the growth performance, feed utilization, and antioxidant capacity of spotted seabass and alleviated the excessive lipid deposition compared with the low-P diet (0.35% P). Moreover, the addition of 0.71-0.92% P to diets increased the diversity of intestinal microbiota and the relative abundance of and decreased the relative abundance of compared with the low-P diet. Thus, dietary supplementation with 0.71-0.82% P improved the growth performance, antioxidant capacity and microbial composition of spotted seabass, and alleviated the disturbance of lipid metabolism caused by high temperature or low-P diet.
PubMed: 38136247
DOI: 10.3390/antiox12122128 -
PloS One 2024This study aimed to investigate the cause of a foodborne disease outbreak in Huzhou on August 14, 2023. Multiple enteropathogens were detected using FilmArray, and the...
This study aimed to investigate the cause of a foodborne disease outbreak in Huzhou on August 14, 2023. Multiple enteropathogens were detected using FilmArray, and the pathogen was subsequently isolated and cultured from anal swabs of the cases and stream water. The isolated strains were identified using VITEK MS, and antimicrobial susceptibility test, pulsed field gel electrophoresis (PFGE) molecular typing, and whole genome sequencing (WGS) were performed on the isolates of Plesiomonas shigelloides. Gene annotation and sequence alignment were used to analyze the virulence genes and drug resistance genes of the strains. A phylogenetic tree was constructed based on single nucleotide polymorphism (SNP), and homology analysis was conducted to trace the origin of P. shigelloides. A total of 7 strains of P.shigelloides were isolated, with 3 from stream water and 4 from anal swabs. All 7 strains exhibited the same PFGE pattern and showed resistance to amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, tetracycline, cefazolin, streptomycin, and florfenicol. The isolated strains carried the same resistance genes and virulence factors. In the sequences of the isolated strains from this outbreak, 11 mutation sites were detected. The phylogenetic tree based on SNP sites showed that these strains were homologous. This foodborne disease outbreak caused by P.shigelloides was the first reported in Huzhou. WGS can be used as a complementary method to PFGE for epidemiological investigations of disease outbreaks.
Topics: Humans; Plesiomonas; Rivers; Phylogeny; Diarrhea; Foodborne Diseases; Water
PubMed: 38574097
DOI: 10.1371/journal.pone.0301623 -
PeerJ 2023The Andean condor () is the largest scavenger in South America. This predatory bird plays a crucial role in their ecological niche by removing carcasses. We report the...
BACKGROUND
The Andean condor () is the largest scavenger in South America. This predatory bird plays a crucial role in their ecological niche by removing carcasses. We report the first metagenomic analysis of the Andean condor gut microbiome.
METHODS
This work analyzed shotgun metagenomics data from a mixture of fifteen captive Chilean Andean condors. To filter eukaryote contamination, we employed BWA-MEM v0.7. Taxonomy assignment was performed using Kraken2 and MetaPhlAn v2.0 and all filtered reads were assembled using IDBA-UD v1.1.3. The two most abundant species were used to perform a genome reference-guided assembly using MetaCompass. Finally, we performed a gene prediction using Prodigal and each gene predicted was functionally annotated. InterproScan v5.31-70.0 was additionally used to detect homology based on protein domains and KEGG mapper software for reconstructing metabolic pathways.
RESULTS
Our results demonstrate concordance with the other gut microbiome data from New World vultures. In the Andean condor, Firmicutes was the most abundant phylum present, with , a potentially pathogenic bacterium for other animals, as dominating species in the gut microbiome. We assembled all reads corresponding to the top two species found in the condor gut microbiome, finding between 94% to 98% of completeness for and , respectively. Our work highlights the ability of the Andean condor to act as an environmental reservoir and potential vector for critical priority pathogens which contain relevant genetic elements. Among these genetic elements, we found 71 antimicrobial resistance genes and 1,786 virulence factors that we associated with several adaptation processes.
Topics: Animals; Gastrointestinal Microbiome; Metagenomics; Falconiformes; Acclimatization; Chile; Clostridium perfringens
PubMed: 37434868
DOI: 10.7717/peerj.15235 -
Antioxidants (Basel, Switzerland) Jun 2023This study aimed to investigate the potential adverse effects of the practical application of copper sulfate on yellow catfish () and to provide insights into the gill...
This study aimed to investigate the potential adverse effects of the practical application of copper sulfate on yellow catfish () and to provide insights into the gill toxicity induced by copper sulphate. Yellow catfish were exposed to a conventional anthelmintic concentration of copper sulphate (0.7 mg/L) for seven days. Oxidative stress biomarkers, transcriptome, and external microbiota of gills were examined using enzymatic assays, RNA-sequencing, and 16S rDNA analysis, respectively. Copper sulphate exposure led to oxidative stress and immunosuppression in the gills, with increased levels of oxidative stress biomarkers and altered expression of immune-related differentially expressed genes (DEGs), such as IL-1β, IL4Rα, and CCL24. Key pathways involved in the response included cytokine-cytokine receptor interaction, NOD-like receptor signaling pathway, and Toll-like receptor signaling pathway. The 16S rDNA analysis revealed copper sulphate altered the diversity and composition of gill microbiota, as evidenced by a significant decrease in the abundance of Bacteroidotas and Bdellovibrionota and a significant increase in the abundance of Proteobacteria. Notably, a substantial 8.5-fold increase in the abundance of was also observed at the genus level. Our findings demonstrated that copper sulphate induced oxidative stress, immunosuppression, and gill microflora dysbiosis in yellow catfish. These findings highlight the need for sustainable management practices and alternative therapeutic strategies in the aquaculture industry to mitigate the adverse effects of copper sulphate on fish and other aquatic organisms.
PubMed: 37372018
DOI: 10.3390/antiox12061288