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Food Science & Nutrition Feb 2020, an inhabitant in the aquatic ecosystem is considered as an important foodborne bacterial zoonotic pathogen in aquaculture. The present study aimed to identify virulent...
, an inhabitant in the aquatic ecosystem is considered as an important foodborne bacterial zoonotic pathogen in aquaculture. The present study aimed to identify virulent from naturally infected in river Cauvery and in vitro evaluation of shrimp chitosan. Rimler Shotts (RS) and blood agar medium identified the presence of pathogenic sp. from the infected . Ah17 was identified using 16S rRNA nucleotide sequence. Extracellular enzymes such as amylase, lipase, and protease were screened in Ah17. Antibiotic susceptibility tests showed Ah17 was highly resistant against -lactam, glycopeptide, macrolides, phosphonic, fucidin, and oxazolidinone classes of antibiotics. Virulent genes such as hemolysin ( and , heat-labile enterotoxin (), cytotonic heat-stable enterotoxin (), elastase (), and lipase () were identified. Growth and the viable cell population of virulent Ah17 were significantly reduced in a dose-dependent manner against shrimp chitosan (CHS) from (). Thus, the present study isolated virulent Ah17 from the environmental source and characterized in vitro with shrimp chitosan.
PubMed: 32148833
DOI: 10.1002/fsn3.1416 -
Virulence Dec 2022The molecular mechanisms underlying -pathogenesis are not well understood. Using head kidney macrophages (HKM) of , we previously reported the role of ER-stress in...
The molecular mechanisms underlying -pathogenesis are not well understood. Using head kidney macrophages (HKM) of , we previously reported the role of ER-stress in -induced pathogenesis. Here, we report that PI3K/PLC-induced cytosolic-Ca imbalance induces the expression of pro-apoptotic ER-stress marker, CHOP in infected HKM. CHOP promotes HKM apoptosis by inhibiting AKT activation and enhancing JNK signaling. Elevated mitochondrial ROS (mtROS) was recorded which declined significantly by ameliorating ER-stress and in the presence of ER-Ca release modulators (2-APB and dantrolene) and mitochondrial-Ca uptake inhibitor, Ru360, together suggesting the role of ER-mitochondrial Ca dynamics in mtROS generation. Inhibiting mtROS production reduced HKM death implicating the pro-apoptotic role of mtROS in -pathogenesis. The expression of autophagic proteins (LC3B, beclin-1, and atg 5) was suppressed in the infected HKM. Our results with autophagy-inducer rapamycin demonstrated that impaired autophagy favored the cytosolic accumulation of mitochondrial DNA (mtDNA) and the process depended on mtROS levels. Enhanced caspase-1 activity and IL-1β production was detected and transfection studies coupled with pharmacological inhibitors implicated mtROS/mtDNA axis to be crucial for activating the caspase-1/IL-1β cascade in infected HKM. RNAi studies further suggested the involvement of IL-1β in generating pro-apoptotic NO in -infected HKM. Our study suggests a novel role of ER-mitochondria cross-talk in regulating pathogenesis. Based on our observations, we conclude that induces ER-stress and inhibits mitophagy resulting in mitochondrial dysfunction which leads to mtROS production and translocation of mtDNA into cytosol triggering the activation of caspase-1/IL-1β-mediated NO production, culminating in HKM apoptosis.
Topics: Aeromonas hydrophila; Animals; Apoptosis; Autophagy; Caspase 1; Cytosol; DNA, Mitochondrial; Interleukin-1beta; Macrophages; Mitochondria; Nitric Oxide; Reactive Oxygen Species
PubMed: 34967692
DOI: 10.1080/21505594.2021.2018767 -
Frontiers in Immunology 2022In China, channel catfish () is an important aquaculture species; however, haemorrhagic disease ( induced disease) in these fish has caused tremendous economic loss due...
In China, channel catfish () is an important aquaculture species; however, haemorrhagic disease ( induced disease) in these fish has caused tremendous economic loss due to high morbidity and mass mortality in the breeding industry. The role of cortisol in bacterial diseases, particularly in the acute phase, remains unclear. In this study, liver transcriptome (RNA-seq) and chromatin accessibility (ATAC-seq) analyses were employed to investigate the early functional role of cortisol in -stimulated responses. Our experiments confirmed that infection can initially significantly increase serum cortisol levels at 1 h after infection. At this time point, the increased serum cortisol levels can significantly regulate -regulated genes by affecting both transcriptome and chromatin accessibility. Cross-analysis of RNA-seq and ATAC-seq revealed that a certain gene group (92 target_DEGs) was regulated at an early time point by cortisol. KEGG enrichment analysis revealed that the top three pathways according to target_DEGs were cancer, glutathione metabolism, and the Notch signalling pathway. The protein-protein interaction analysis of target_DEGs revealed that they may be primarily involved in cell proliferation, CD8 T cell function, glutathione synthesis, and activation of the NF-κB signalling pathway. This suggests that after the emergence of immune stress, the early regulation of cortisol is positive against the immune response. It is possible that in this situation, the animal is attempting to avoid dangerous situations and risks and then cope with the imbalance produced by the stressor to ultimately restore homeostasis. Our results will contribute to future research on fish and provide valuable insight regarding the mechanism of immune regulation by cortisol and the study of bacterial haemorrhagic disease in channel catfish.
Topics: Animals; Aeromonas hydrophila; Hydrocortisone; Transcriptome; Chromatin; Gram-Negative Bacterial Infections; Fish Diseases; Ictaluridae; Liver; Glutathione
PubMed: 36532002
DOI: 10.3389/fimmu.2022.989075 -
Microbiological Research Apr 2023Aeromonas hydrophila (Ah) is a zoonotic pathogen of great importance to aquaculture and human health. This study systematically evaluated the impact of salinity, sugar,...
Aeromonas hydrophila (Ah) is a zoonotic pathogen of great importance to aquaculture and human health. This study systematically evaluated the impact of salinity, sugar, ammonia nitrogen, and nitric nitrogen levels on the fitness of Ah by using Luria-Bertani (LB) broth supplemented with different concentrations of NaCl, sucrose, NHCl, urea, NaNO or NaNO. Results showed that the static biofilm formation of Ah was higher at 28 °C compared to 37 °C (P < 0.05). At 28 °C, as the NaCl (>1 %) and sucrose levels increased, the Ah biofilm formation and the binding between Ah cells and monoclonal antibodies (mAbs, for immunodetection) decreased. Elevated ammonia nitrogen and nitric nitrogen levels generated no significant impact on Ah biofilm formation or immunodetection (P > 0.05). The expression of mAbs-targeted Omp remained unchanged under high NaCl or sucrose conditions. Further analysis showed that high sucrose conditions led to the over-expression of the extracellular polysaccharides (PS) and promoted the formation of capsule-like structures. These over-expressed PS and capsule structures might be one reason explaining the inhibited immunodetection efficacy. Results generated from this study provide crucial insights for the design of recovery and detection protocols for Ah present in food or environmental samples.
Topics: Humans; Aeromonas hydrophila; Osmotic Pressure; Sodium Chloride; Ammonia; Biofilms; Sucrose
PubMed: 36689842
DOI: 10.1016/j.micres.2023.127301 -
Frontiers in Microbiology 2021The prevalence of -positive bacteria in 5,169 domestic animal-derived samples collected by USDA Food Safety and Inspection Service between October 2018 and May 2019 was...
The prevalence of -positive bacteria in 5,169 domestic animal-derived samples collected by USDA Food Safety and Inspection Service between October 2018 and May 2019 was investigated. A procedure including enriched broth culture and real-time PCR targeting to were used for the screening. Fifteen positive isolates were identified, including one plasmid-borne -positive strain, EC2492 (reported elsewhere) and 14 -positive strains from poultry (1), catfish (2), and chicken rinse (11) samples, resulting in an overall prevalence of -positive bacteria 0.29% in all meat samples tested. Analysis of 16S rRNA and whole genome sequences revealed that all 14 strains belonged to . Data from phylogenetic analysis of seven housekeeping genes, including , and , indicated that nine strains belonged to and five strains belonged to . Antimicrobial tests showed that almost all -positive strains exhibited high resistance to colistin with MICs ≥ 128mg/L, except for one strain, which showed a borderline resistance with a MIC of 2 mg/L. A segment containing two adjacent and lik genes was found in two and one strains and a variety of IS-like elements were found in the flanking regions of this segment. A -related lipid A phosphoethanolamine transferase gene was present in all 14 strains, while an additional -related lipid A phosphoethanolamine transferase gene was found in 5 strains only. In addition to genes, other antimicrobial resistance genes, including , , , , , , , , and were observed in chromosomes of some strains. The relative high prevalence of chromosome-borne genes and the close proximity of various IS elements to these genes highlights the need for continued vigilance to reduce the mobility of these colistin-resistance genes among food animals.
PubMed: 33995332
DOI: 10.3389/fmicb.2021.667406 -
Veterinary World May 2020This study aimed to examine the intestinal histopathological lesions and mucous cell responses in the entire intestines of Nile tilapia administered with GG (LGG)-mixed...
AIM
This study aimed to examine the intestinal histopathological lesions and mucous cell responses in the entire intestines of Nile tilapia administered with GG (LGG)-mixed feed, after challenge.
MATERIALS AND METHODS
Intestinal samples from fish fed with control normal diet or LGG-mixed feed (10 colony-forming unit [CFU]/g feed) with or without in phosphate-buffered saline challenge (7.46 × 10 CFU/mL/fish) were collected and processed for histopathological study. The mucous cell responses were evaluated using histochemistry, using Alcian blue (AB) at pH 2.5, AB at pH 1.0, and periodic acid-Schiff-AB at pH 2.5. The quantification of the intestinal mucous cell size and the staining character of each mucin type from the entire intestine were recorded and counted.
RESULTS
Histopathological study showed remarkable lesions only in the proximal intestine in fish infected with , while LGG-fed fish had less intestinal damage, perhaps resulting from heterophil infiltration. Furthermore, a significant (p<0.01) increase in mixed mucous cell numbers was observed mainly in the proximal intestine of all challenged fish, compared with normal diet-fed fish without challenge, and also in LGG-fed fish with challenge compared with LGG-fed fish without challenge.
CONCLUSION
Dietary LGG-fed Nile tilapia showed improvements in host innate immunity. In addition, LGG was effective in decreasing intestinal lesions from a-induced intestinal damage. Moreover, increasing numbers of mixed mucous cells in the proximal intestine might be indicative of certain pathological conditions in Nile tilapia after infection.
PubMed: 32636595
DOI: 10.14202/vetworld.2020.967-974 -
Genes Nov 2022() is an important regulator of the p38 mitogen-activated protein kinase (p38 MAPK) pathway, which is involved in a plethora of cellular processes concluding the...
() is an important regulator of the p38 mitogen-activated protein kinase (p38 MAPK) pathway, which is involved in a plethora of cellular processes concluding the development of gamete cells in meiosis and resisting pathogenic bacterial infestation. is a significant mussel resource in China and a good material for pearl breeding. To explore the role of in was identified and cloned, whose full-length cDNA was 1568 bp, including 87 bp in 5' UTR, 398 bp in 3' UTR, and 1083 bp in the open reading frame (ORF) region, encoding 360 amino acids. The expression of was the highest in the gills. Meanwhile, there was a significant difference in the gonads. After and (LPS) infestation, the transcript level of the was upregulated in the gills. It indicated that might be involved in the innate immune response of after a pathogenic attack. After quantifying of different ages, it was found that the expression of was highest at 1 year old. In situ hybridization (ISH) results showed that the blue-purple hybridization signal was very significant in the oocytes and egg membranes of the female gonads of . The expression of increased gradually at the age of 1 to 5 months and showed a downward trend at the age of 5 to 8 months. It was suggested that might play an important role in the formation of primitive germ cells in . To sum up, might not only be involved in the immune response against pathogenic bacterial infection but also might play an important role in the development of the gonads in .
Topics: Female; Animals; Amino Acid Sequence; Base Sequence; Cloning, Molecular; Unionidae
PubMed: 36360298
DOI: 10.3390/genes13112060 -
International Journal of Molecular... Sep 2022is an important pathogen that mainly harms aquatic animals and has exhibited resistance to a variety of antibiotics. Here, to seek an effective alternative for...
is an important pathogen that mainly harms aquatic animals and has exhibited resistance to a variety of antibiotics. Here, to seek an effective alternative for antibiotics, the effects of umbelliferone (UM) at sub-MICs on virulence factors and the quorum-sensing system were studied. Subsequently, RNA sequencing was employed to explore the potential mechanisms for the antivirulence activity of umbelliferone. Meanwhile, the protective effect of umbelliferone on grass carp infected with was studied in vivo. Our results indicated that umbelliferone could significantly inhibit virulence such as hemolysis, biofilm formation, swimming and swarming motility, and their quorum-sensing signals AHL and AI-2. Transcriptomic analysis showed that umbelliferone downregulated expression levels of genes related to exotoxin, the secretory system (T2SS and T6SS), iron uptake, etc. Animal studies demonstrated that umbelliferone could significantly improve the survival of grass carps infected with , reduce the bacterial load in the various tissues, and ameliorate cardiac, splenic, and hepatopancreas injury. Collectively, umbelliferone can reduce the pathogenicity of and is a potential drug for treating infection.
Topics: Aeromonas hydrophila; Animals; Anti-Bacterial Agents; Carps; Exotoxins; Fish Diseases; Gram-Negative Bacterial Infections; Iron; Umbelliferones; Virulence Factors
PubMed: 36232424
DOI: 10.3390/ijms231911119 -
Microorganisms Mar 2023Widespread and inappropriate use of antibiotics has been shown to increase the spread of antibiotics and antimicrobial resistance genes (ARGs) in aquatic environments...
Widespread and inappropriate use of antibiotics has been shown to increase the spread of antibiotics and antimicrobial resistance genes (ARGs) in aquatic environments and organisms. Antibiotic use for the treatment of human and animal diseases is increasing continuously globally. However, the effects of legal antibiotic concentrations on benthic consumers in freshwater environments remain unclear. In the present study, we tested the growth response of to florfenicol (FF) for 84 days under high and low concentrations of sediment organic matter (carbon [C] and nitrogen [N]). We characterized FF and sediment organic matter impact on the bacterial community, ARGs, and metabolic pathways in the intestine using metagenomic sequencing and analysis. The high concentrations of organic matter in the sediment impacted the growth, intestinal bacterial community, intestinal ARGs, and microbiome metabolic pathways of . growth increased significantly following exposure to high organic matter content sediment. Proteobacteria, at the phylum level, and at the genus level, were enriched in the intestines. In particular, fragments of four opportunistic pathogens enriched in the intestine of high organic matter content sediment groups, , , , and , carried 14 ARGs. The metabolic pathways of the intestine microbiome were activated and showed a significant positive correlation with sediment organic matter concentrations. In addition, genetic information processing and metabolic functions may be inhibited by the combined exposure to sediment C, N, and FF. The findings of the present study suggest that antibiotic resistance dissemination from benthic animals to the upper trophic levels in freshwater lakes should be studied further.
PubMed: 36985338
DOI: 10.3390/microorganisms11030765 -
BioMed Research International 2021The main aim of this study was to develop a set of functions that can analyze the genomic data with less time consumption and memory. Epi-gene is presented as a solution...
The main aim of this study was to develop a set of functions that can analyze the genomic data with less time consumption and memory. Epi-gene is presented as a solution to large sequence file handling and computational time problems. It uses less time and less programming skills in order to work with a large number of genomes. In the current study, some features of the Epi-gene R-package were described and illustrated by using a dataset of the 14 genomes. The joining, relabeling, and conversion functions were also included in this package to handle the FASTA formatted sequences. To calculate the subsets of core genes, accessory genes, and unique genes, various Epi-gene functions have been used. Heat maps and phylogenetic genome trees were also constructed. This whole procedure was completed in less than 30 minutes. This package can only work on Windows operating systems. Different functions from other packages such as dplyr and ggtree were also used that were available in R computing environment.
Topics: Aeromonas hydrophila; Databases, Genetic; Genome, Bacterial; Genomics; Multigene Family; Phylogeny; Principal Component Analysis; Software
PubMed: 34595238
DOI: 10.1155/2021/5585586