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Frontiers in Immunology 2024, a bacterium widely distributed in the natural environment, causes multiple diseases in various animals. Exploring the mechanism of the host defense against can help...
Integrated time-series biochemical, transcriptomic, and metabolomic analyses reveal key metabolites and signaling pathways in the liver of the Chinese soft-shelled turtle () against infection.
INTRODUCTION
, a bacterium widely distributed in the natural environment, causes multiple diseases in various animals. Exploring the mechanism of the host defense against can help develop efficient strategies against infection.
METHODS
Herein, we investigated the temporal influence of A. hydrophila on the Chinese soft-shelled turtle, an economically important species, at the biochemical, transcriptomic, and metabolomic levels. Plasma parameters were detected with the test kits. Transcriptome and metabolome were respectively applied to screen the differentially expressed genes and metabolites.
RESULTS
The contents or activities of these plasma parameters were significantly increased at 24 hpi and declined at 96 hpi, indicating that 24 and 96 hpi were two important time points during infection. Totals of 3121 and 274 differentially expressed genes (DEGs) from the transcriptome while 74 and 91 differentially abundant metabolites (DAMs) from the metabolome were detected at 24 and 96 hpi. The top DEGs at 24 hpi included and while and were the most abundant at 96 hpi. The predominant DAMs included O-phospho-L-serine, γ-Aminobutyric acid, orotate, L-tyrosine, and L-tryptophan at 24 hpi, as well as L-glutamic acid, L-arginine, glutathione, glutathione disulfide, and citric acid at 96 hpi.
DISCUSSION
The combined analysis of DEGs and DAMs revealed that tryptophan metabolism, nicotinate and nicotinamide metabolism, as well as starch and sucrose metabolism, were the most important signaling pathways at the early infective stage while tyrosine metabolism, pyrimidine metabolism, as well as alanine, aspartate and glutamate metabolism were the most crucial pathways at the later stage. In general, our results indicated that the Chinese soft-shelled turtle displays stage-specific physiological responses to resist infection.
Topics: Animals; Turtles; Aeromonas hydrophila; Gram-Negative Bacterial Infections; Signal Transduction; Metabolomics; Liver; Metabolome; Transcriptome; Gene Expression Profiling
PubMed: 38799475
DOI: 10.3389/fimmu.2024.1376860 -
Foods (Basel, Switzerland) Oct 2022, an opportunistic aquatic pathogen widely spread in aquatic environments, is responsible for a number of infectious diseases in freshwater aquaculture. In addition,...
, an opportunistic aquatic pathogen widely spread in aquatic environments, is responsible for a number of infectious diseases in freshwater aquaculture. In addition, can transmit from diseased fish to humans and results in health problems. The occurrence of antibiotic-resistant bacterial strains restricts the application of antibiotics and is responsible for failure of the treatment. Moreover, residues of antibiotics in aquatic products often threaten the quality and safety. Therefore, alternative strategies are called to deal with infections caused by antibiotic-resistant bacteria. Aerolysin, one of the most important virulence factors of , is adopted as a unique anti-virulence target on the basis of the anti-virulence strategy to battling infections caused by . Palmatine, an isoquinoline alkaloid from a variety of herbal medicines that showed no anti- activity, could reduce hemolysis of the bacterium by decreasing aerolysin production. The results of the qPCR assay demonstrated that the transcription of the gene was suppressed. Moreover, cell viability and in vivo study showed that palmatine treatment could decrease the pathogenicity of both in vitro and in vivo. In summary, palmatine is a leading compound against -associated infection in aquaculture by inhibiting the expression of aerolysin.
PubMed: 37430999
DOI: 10.3390/foods11203250 -
MSphere Aug 2022Bacterial pathogens are well equipped to adhere to and initiate infection in teleost fish. Fish skin mucus serves as the first barrier against environmental pathogens....
Bacterial pathogens are well equipped to adhere to and initiate infection in teleost fish. Fish skin mucus serves as the first barrier against environmental pathogens. The mucus harbors commensal microbes that impact host physiological and immunological responses. However, how the skin mucosal microbiota responds to the presence of pathogens remains largely unexplored. Thus, little is known about the status of skin mucus prior to infection with noticeable symptoms. In this study, we investigated the interactions between pathogens and the skin mucosal microbiota as well as the fish skin immune responses in the presence of pathogens. Striped catfish (Pangasianodon hypophthalmus) were challenged with different concentrations of the bacterial pathogen Aeromonas hydrophila (AH), and the skin immune response and the mucosal microbiota were examined by quantitative PCR (qPCR) and 16S rRNA gene sequence analysis. We determined that the pathogen concentration needed to stimulate the skin immune response was associated with significant mucosal microbiota changes, and we reconfirmed these observations using an fish skin model. Further analysis indicated that changes in the microbiota were attributed to a significant increase in opportunistic pathogens over AH. We concluded that the presence and increase of AH result in dysbiosis of the mucosal microbiota that can stimulate skin immune responses. We believe that our work sheds light on host-pathogen-commensal microbiota interactions and therefore contributes to aquaculture fish health. The fish skin mucosal microbiota is essential in modulating the host response to the presence of pathogens. Our study provides a platform to study both the correlation and causation of the interactions among the pathogen, fish skin, and the skin mucosal microbiota. Based on these findings, we provide the first mechanistic information on how mucosal microbiota changes induced by the pathogen AH result in skin disturbance with immune stimulation in striped catfish in the natural state and a potential direction for early-infection screening. Thus, this study is highly significant in the prevention of fish disease.
Topics: Aeromonas hydrophila; Animals; Catfishes; Dysbiosis; Microbiota; RNA, Ribosomal, 16S
PubMed: 35766485
DOI: 10.1128/msphere.00194-22 -
F1000Research 2023Strategies to increase body resistance and prevent disease in aquaculture include using vaccines, antibiotics, and probiotics. Today, the use of antibiotics with...
Strategies to increase body resistance and prevent disease in aquaculture include using vaccines, antibiotics, and probiotics. Today, the use of antibiotics with natural ingredients is becoming a trend. One of the natural ingredients that contain high antioxidants and antibiotics is sp. This research was conducted from March to May 2022 at the Biotechnology Laboratory, Faculty of Fisheries and Marine, Universitas Riau, in two stages: 1) the sensitivity of extracts of sp. and 2) the application of sp. extract orally in tilapia ( ). The parameters measured were clear zone, minimum inhibitory concentration, LD test of leaf extract of sp. in tilapia ( ), hemoglobin levels, hematocrit, total leukocytes, total erythrocytes, leukocyte differentiation, and survival rate. Data on hematology parameters were tabulated and analyzed using a One-Way ANOVA followed by a Student Newman Keuls (SNK) test when deemed necessary. The results showed that the extract of sp. inhibited the growth of bacteria with a clear zone of 6.5-15.0 mm, which is classified as resistant. At doses of 2000, 2500, and 3000 ppm, it did not cause death in fish for 96 hours (LD ). Hematological parameters can be a sign of the health status of fish. Tilapia given sp. in different doses gave an effect between treatments, both after 30 days of rearing and post-test against bacteria (p<0.05). The results showed that the hematology of fish fed with sp. extract was in the normal or healthy range. Healthy tilapia had erythrocyte counts ranging from 1.34-2.11×10 cells/mm , hematocrit 26.17-33.19%, hemoglobin 6.26-11.2 g/dL and total leukocytes 1.01-1.50×10 cells/mm and total erythrocytes 5.88-9.13×10 cells/ mm . A dose of 3000 ppm provided the highest health improvement against bacterial infection.
Topics: Animals; Sargassum; Cichlids; Aeromonas hydrophila; Microbial Sensitivity Tests; Anti-Bacterial Agents; Fish Diseases
PubMed: 38817412
DOI: 10.12688/f1000research.128819.2 -
GE Portuguese Journal of... Jan 2023are Gram-negative rods known to cause a spectrum of diseases. Inflammatory bowel disease (IBD) is an idiopathic complex condition resulting from interaction of multiple...
BACKGROUND AND AIM
are Gram-negative rods known to cause a spectrum of diseases. Inflammatory bowel disease (IBD) is an idiopathic complex condition resulting from interaction of multiple factors. Aeromonas infection in association with IBD is still largely unknown. We aim to look for the significance of infection and for significant differences between IBD and non-IBD patients.
METHODS
A retrospective observational analysis was performed of all patients positive for in stool cultures, during a 10-year period, from a tertiary and university hospital.
RESULTS
Fifty patients were included, 56% male with a mean age of 42.1 years. Thirty-eight (76%) were non-IBD and 12 (24%) IBD patients. IBD patients were more frequently under immunosuppressors. Two patients were asymptomatic and 44% developed mild, 44% moderate, and 16.7% severe infection. The main strains isolated were . Bacterial co-isolation was found in 4 non-IBD and histological findings of cytomegalovirus in 2 IBD patients. Non-IBD patients presented more frequently with fever and IBD patients with bloody diarrhea and abdominal pain. There was higher tendency for severe infection rate in IBD patients with higher antimicrobial therapy use. Steroids were exclusively used in the IBD group. From IBD, 4 patients had the diagnosis of ulcerative colitis and 9 of Crohn's disease with colonic involvement. Of these patients, 5 received IBD diagnosis after the acute episode of infection.
CONCLUSIONS
Clinical presentation of infection differs between IBD and non-IBD patients. Non-IBD patients had milder severity of infection with less use of antibiotics. infection seems to greatly contribute to IBD manifestation.
PubMed: 36743987
DOI: 10.1159/000520272 -
Frontiers in Microbiology 2021Quorum sensing (QS) and biofilm formation inhibition activity of esculetin on SHAe 115 were evaluated. Exposure to esculetin at 25, 50, and 100μg/ml significantly...
Quorum sensing (QS) and biofilm formation inhibition activity of esculetin on SHAe 115 were evaluated. Exposure to esculetin at 25, 50, and 100μg/ml significantly inhibited the production of protease and hemolysin, the formation of biofilms and attenuated the swarming motility of SHAe 115. Biofilm forming inhibition was also observed through confocal laser scanning microscopy and scanning electron microscope. Quantitative real-time PCR analysis indicated that genes positively related to QS and biofilm formation were downregulated to varying degrees, while gene () negatively related to biofilm formation was significantly upregulated. The phenotypic results were in good agreement with gene expression levels. These results indicated that esculetin would be a potential QS inhibitor for .
PubMed: 34630364
DOI: 10.3389/fmicb.2021.737626 -
Veterinary World Jul 2022Motile Aeromonas septicemia is a crucial disease in freshwater fish. Aeromonas hydrophila is a disease agent associated with sporadic fish mortality, food safety, and...
BACKGROUND AND AIM
Motile Aeromonas septicemia is a crucial disease in freshwater fish. Aeromonas hydrophila is a disease agent associated with sporadic fish mortality, food safety, and public health. This study aimed to estimate the prevalence and the presence of the aerolysin gene and antimicrobial resistance profile of A. hydrophila isolated from milkfish in Gresik, Indonesia.
MATERIALS AND METHODS
A total of 153 milkfish gill samples were collected from 16 locations in Gresik and then cultured and identified using biochemical tests. The aerolysin gene was investigated using a polymerase chain reaction, and antimicrobial resistance profiles of the recovered isolates were investigated.
RESULTS
Of the 153 examined samples, 35 (22.9%) were confirmed positive for A. hydrophila and 22 (62.9%) presented the aerolysin gene. The recovered isolates were resistant to the following antibiotics: Amoxicillin (62.9%), tetracycline (60%), streptomycin (54.3%), cefotaxime (51.4%), gentamycin (31.4%), kanamycin (28.6%), erythromycin (25.7%), chloramphenicol (20%), and trimethoprim (14.3%). Meanwhile, only ciprofloxacin, nalidixic acid, and imipenem were indicated as susceptible.
CONCLUSION
The presence of the aerolysin gene is vital in determining the virulence of A. hydrophila. The study results indicated a high aerolysin gene prevalence. In addition, this study emphasized antibiotic use monitoring, food safety improvement, and negative impact reduction on human health and the environment.
PubMed: 36185507
DOI: 10.14202/vetworld.2022.1759-1764 -
Biocontrol Science 2021Aeromonas hydrophila is a major waterborne pathogen, which induces various diseases in freshwater fish with the capability for zoonotic potential. This study was applied...
Virulent and Multiple Antimicrobial Resistance Aeromonas hydrophila Isolated from Diseased Nile Tilapia Fish (Oreochromis niloticus) in Egypt with Sequencing of Some Virulence-Associated Genes.
Aeromonas hydrophila is a major waterborne pathogen, which induces various diseases in freshwater fish with the capability for zoonotic potential. This study was applied to investigate the prevalence of A. hydrophila in diseased Nile tilapia fish, genetic characterization of the virulence encoding genes (act, aerA, alt, and ast genes), and antibiotic susceptibility. Out of the 500 diseased Nile tilapia fish samples, 70% (350/500) Aeromonas species were isolated. From which 53.4% (187/350) of Aeromonas hydrophila strains were identified. A. hydrophila was detected in kidneys, followed by liver, spleen, intestine, and gills. The results of virulotyping displayed the presence of act, and aerA genes in a high percentage of 40%, followed by alt gene (30%), but ast gene was not detected (0%) in A. hydrophila strains. Based on DNA sequence analysis of three virulence associated-genes (act, aerA, and alt genes), the phylogenetic tree showed the genetic relationship with related species. Finally, the antibiotic susceptibility tests revealed high resistance toward chloramphenicol (67.4%), followed by amikacin (51.9%) and gentamicin (47.1%), whereas a high sensitivity was exhibited toward meropenem (90.9%), followed by ciprofloxacin (84.2%), amoxicillin-clavulanic acid (73.3%) and trimethoprim-sulfamethoxazole (64.2%). The multidrug-resistant A. hydrophila strains were observed in 69.0% of strains with six resistance patterns.
Topics: Aeromonas hydrophila; Animals; Anti-Bacterial Agents; Cichlids; Drug Resistance, Bacterial; Egypt; Fish Diseases; Phylogeny; Virulence
PubMed: 34556619
DOI: 10.4265/bio.26.167 -
PeerJ 2021Motile septicaemia (MAS), caused by , is one of the most significant bacterial disease responsible for mortality in Indian catfish, , a potential aquaculture species in...
Motile septicaemia (MAS), caused by , is one of the most significant bacterial disease responsible for mortality in Indian catfish, , a potential aquaculture species in the Indian subcontinent. In fish, innate immunity elicited by pathogen recognition receptors (PRRs) plays an important role in providing protection against bacterial infection. Information on PRRs including Toll-like receptors () and their response to bacterial pathogens remains unexplored in magur. Toll-like receptor 2 (), a phylogenetically conserved germ-line encoded PRR recognizes specific microbial structure and trigger MyD88-dependent signaling pathway to induce release of various cytokines responsible for innate immune response. In the present study, gene of magur was characterized and downstream signaling was studied following challenge with . The full-length cDNA of () comprised of 3,066 bp with a single open reading frame of 2,373 bp encoding 790 amino acids having a theoretical pI value of 6.11 and molecular weight of 90 kDa. Structurally, it comprised of signal peptide (1-42aa), one leucine-rich repeat region (LRR) at N-terminal (LRR1-NT: 50-73 aa) and C-terminal (LRR-CT: 588-608 aa), twenty LRRs in between, one trans-membrane (Tm) domain (609-631aa) followed by cytoplasmic TIR domain (670-783aa). Phylogenetically, is closely related to pangasius and channel catfish. Highest basal expression of , and in spleen, in anterior kidney was observed. Lowest basal expression of in skin and 88, - and in muscle was detected. Significant up-regulation of and downstream expression occurred at 3, 8, 24 h post infection to in important immune organs such as liver, spleen, intestine and kidney. These findings highlight the vital role of in eliciting innate immune defence against infection.
PubMed: 34909268
DOI: 10.7717/peerj.12411 -
BMC Research Notes Jun 2024The aim of this study was to quantify and identify metabolites of Ice Nucleation Active (INA) bacteria as an anti-biofilm agent against biofilms of fish pathogens such...
OBJECTIVES
The aim of this study was to quantify and identify metabolites of Ice Nucleation Active (INA) bacteria as an anti-biofilm agent against biofilms of fish pathogens such as Aeromonas hydrophila and Streptococcus agalactiae.
RESULTS
Ice nucleation active bacteria, which have the ability to catalyze ice nucleation, isolated from rainwater in previous studies, were used. All INA isolates were tested in several assays, including the antimicrobial test, which uses streptomycin as the positive control and none of the isolates were found positive in the antimicrobial test. As for the quorum quenching assay, it was found that four out of ten isolates were able to disturb the communication system in Chromobacterium violaceum wild type, which was used as the indicator bacteria. On the next assay, all ten isolates were tested for Biofilm Inhibition and Destruction and showed anti-biofilm activity with the highest percentage inhibition of 33.49% by isolate A40 against A. hydrophila and 77.26% by isolate A19 against S. agalactiae. C1 performed the highest destruction against A. hydrophila and S. agalactiae, with percentages of 32.11% and 51.88%, respectively. As for the GC-MS analysis, supernatants of INA bacteria contain bioactive compounds such as sarcosine and fatty acids, which are known to have antibiofilm activity against several biofilm-forming bacteria. Through 16s rRNA sequencing, identified bacteria are from the Pantoea, Enterobacter, and Acinetobacter genera. As for the conclusion, ice nucleation active bacteria metabolites tested showed positive results against pathogenic bacteria Aeromonas hydrophila and Streptococcus agalactiae in destructing and inhibiting biofilm growth.
Topics: Biofilms; Aeromonas hydrophila; Streptococcus agalactiae; Anti-Bacterial Agents; Aquaculture; Fish Diseases; Animals; RNA, Ribosomal, 16S; Microbial Sensitivity Tests; Gram-Negative Bacterial Infections; Ice; Streptococcal Infections; Quorum Sensing
PubMed: 38886828
DOI: 10.1186/s13104-024-06821-9