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PloS One 2024Aeromonas hydrophila is one of the major pathogenic bacteria responsible for causing severe outbreaks at fish farms and is also a major global public health concern....
Aeromonas hydrophila is one of the major pathogenic bacteria responsible for causing severe outbreaks at fish farms and is also a major global public health concern. This bacterium harbors many virulence genes. The current study was designed to evaluate the antidrug and virulence potential of A. hydrophila by amplifying its antimicrobial resistance and virulence genes using PCR and examining their effects on fish tissues and organs. A total of 960 fish samples of Channa marulius and Sperata sarwari were collected from four sites of the rivers of the Punjab, Pakistan. A. hydrophila isolates were subjected to biochemical identification and detection of virulence and antimicrobial resistance (AMR) genes by PCR. We retrieved 181 (6.46%) A. hydrophila isolates from C. marulius and 177 (6.25%) isolates from S. sarwari. Amplification through PCR revealed the incidence of virulence genes in 95.7% of isolates in C. marulius and 94.4% in S. sarwari. Similarly, amplification through PCR also revealed occurrence of AMR genes in 87.1% of isolates in C. marulius and 83.9% in S. sarwari. Histopathological examination revealed congestion (5.2%) and hepatocyte necrosis (4.6%) in liver, lamellar fusion (3.3%) and the presence of bacterial colonies (3.7%) in gills, fin erosion (6%), and the presence of biofilms (3.5%) in tail fins of infected fish. Phylogenetic tree analysis of 16S rRNA and gyrB gene of A. hydrophila revealed 100% and 97% similarity, respectively, with 16S rRNA gene and gyrB of A. hydrophila isolated in previous studies. The results of antimicrobial susceptibility testing showed that all isolates demonstrated resistance to sulfamethoxazole, ampicillin, neomycin, and norfloxacin, while susceptibility to gentamicin, chloramphenicol, and tetracycline, and intermediate resistance was observed against cefotaxime. The results concluded that examined fish samples were markedly contaminated with virulent and multidrug strains of A. hydrophila which may be of a potential health risk. The study emphasizes the responsible antimicrobial use in aquaculture and the urgent need for effective strategies to control the spread of virulence and antimicrobial resistance genes in A. hydrophila.
Topics: Animals; Aeromonas hydrophila; Phylogeny; Pakistan; RNA, Ribosomal, 16S; Anti-Bacterial Agents; Catfishes; Aeromonas; Gram-Negative Bacterial Infections
PubMed: 38551906
DOI: 10.1371/journal.pone.0297979 -
Microorganisms Feb 2024Antibiotic resistance remains one of the most pressing public health issues facing the world today. At the forefront of this battle lies the ever-increasing...
Antibiotic resistance remains one of the most pressing public health issues facing the world today. At the forefront of this battle lies the ever-increasing identification of extended-spectrum beta-lactamases and carbapenemases within human pathogens, conferring resistance towards broad-spectrum and last-resort antimicrobials. This study was prompted due to the identification of a pathogenic isolate (strain MAH-4) collected from abdominal fluid, which presented a robust resistance pattern against second-, third-, and fourth-generation cephalosporins, ertapenem, ciprofloxacin, gentamicin, levofloxacin and moxifloxacin, and beta lactam/beta-lactamase inhibitor combinations. Whole genome sequencing was performed and identified a 328 kb plasmid (pMAH4) encoding 10 antibiotic resistance genes, including , , and of MAH-4. This is the first report of beta-lactamase SFO-1 within a clinical strain of . Due to the remarkable sequence identity of pMAH4 to plasmids associated with genera like and the extensive capabilities of for horizontal gene transfer, our identification of a clinical isolate encoding SFO-1 on a plasmid suggests antibiotic resistance gene mobility between and non- species.
PubMed: 38543545
DOI: 10.3390/microorganisms12030494 -
Microorganisms Feb 2024Fenofibrate is a fibric acid derivative used as an antihyperlipidemic drug in humans. Its active metabolite, fenofibric acid, acts as an agonist to the peroxisome...
Fenofibrate is a fibric acid derivative used as an antihyperlipidemic drug in humans. Its active metabolite, fenofibric acid, acts as an agonist to the peroxisome proliferator-activated receptor alpha (PPAR-α), a transcription factor involved in different metabolic pathways. Some studies have reported the potential protective role of this drug in cell lines and in vivo models against bacterial and viral infections. The aim of this study was to assess the in vitro effect of fenofibrate in the macrophage cell line J744A.1 against infections produced by , a pathogen for humans whose resistance to antibiotics has increased in recent decades. Macrophages were infected at MOI 10 with four strains of and isolated from human clinical samples and subsequently treated with fenofibrate. It was observed that fenofibrate-treated macrophages showed lower levels of cytotoxicity and intracellular bacteria compared to non-treated macrophages. In addition, the viability of treated macrophages was dependent on the dose of fenofibrate used. Furthermore, transcriptional analysis by RT-qPCR revealed significant differences in the expression of the gene and immune-related genes , , and in fenofibrate-treated macrophages compared to the macrophages without treatment. This study provides evidence that fenofibrate offered some protection in vitro in macrophages against infection. However, further studies are needed with other bacteria to determine its potential antibacterial effect and the route by which this protection is achieved.
PubMed: 38543516
DOI: 10.3390/microorganisms12030465 -
Veterinary Medicine and Science May 2024Doxycycline (DO) has been used in fish for a long time, but there are some factors that have not yet been clarified regarding its pharmacokinetic (PK) and...
Pharmacokinetic behaviour and pharmacokinetic-pharmacodynamic integration of doxycycline in rainbow trout (Oncorhynchus mykiss) after intravascular, intramuscular and oral administrations.
OBJECTIVE
Doxycycline (DO) has been used in fish for a long time, but there are some factors that have not yet been clarified regarding its pharmacokinetic (PK) and pharmacodynamic (PD) properties. Therefore, the aim of this study was to investigate the PK and PK/PD targets of DO after 20 mg/kg intravascular (IV), intramuscular (IM) and oral (OR) gavage administration in rainbow trout (Oncorhynchus mykiss).
METHODS
Plasma samples were collected at specific time points and subsequently analysed by HPLC-ultraviolet. The PK/PD indices were calculated based on the MIC (Aeromonas hydrophila and Aeromonas sobria) values obtained for the respective bacteria and the PK parameters obtained for DO following both IM and OR administration.
RESULTS
After IV administration, the elimination half-life (t ), area under the concentration vs. time curve (AUC), apparent volume of distribution at steady-state and total body clearance of DO were 34.81 h, 723.82 h µg/mL, 1.24 L/kg and 0.03 L/kg/h, respectively. The t of the DO was found to be 37.39 and 39.78 h after IM, and OR administration, respectively. The bioavailability was calculated 57.02% and 32.29%, respectively, after IM and OR administration. The MIC of DO against A. hydrophila and A. sobria was 4 µg/mL. The PK/PD integration showed that DO (20 mg/kg dose) for A. hydrophila and A. sobria with MIC ≤4 µg/mL achieved target AUC/MIC value after IM administration.
CONCLUSIONS
These results suggest that when rainbow trout was treated with 20 mg/kg IV and IM administered DO, therapeutically effective concentrations were reached in the control of infections caused by A. hydrophila and A. sobria.
Topics: Animals; Doxycycline; Oncorhynchus mykiss; Administration, Oral; Biological Availability
PubMed: 38520701
DOI: 10.1002/vms3.1419 -
Frontiers in Cellular and Infection... 2024This investigation delves into elucidating the mechanism by which resveratrol (Res), a natural polyterpenoid renowned for its antimicrobial properties, exerts its...
This investigation delves into elucidating the mechanism by which resveratrol (Res), a natural polyterpenoid renowned for its antimicrobial properties, exerts its effects on , a ubiquitous waterborne pathogen. Our findings underscore the dose-dependent manifestation of resveratrol in exhibiting antibacterial and antibiofilm formation activities against . Employing a Data-independent acquisition (DIA) based quantitative proteomics methodology, we systematically compared differentially expressed proteins in subjected to varying concentrations of Res. Subsequent bioinformatics analyses revealed key proteins and pathways pivotal in resveratrol's antimicrobial action, encompassing oxidative stress, energy metabolism, and cell membrane integrity. Validation of the proteomics outcomes was meticulously conducted using the qPCR method at the mRNA level. Dynamic trend analysis unveiled alterations in biological processes, notably the correlation between the cell division-related protein ZapC and resveratrol content. Furthermore, scanning electron microscopy corroborated a significant elongation of cells, affirming resveratrol's capability to inhibit cell division. In concert, resveratrol emerges as a participant in the cell membrane integrity pathway, biofilm formation, and potentially, the regulation of genes associated with cell division, resulting in morphological elongation. These revelations position resveratrol as a promising natural alternative to conventional antibiotics for treating infections.
Topics: Humans; Aeromonas hydrophila; Resveratrol; Proteomics; Bacterial Proteins; Anti-Bacterial Agents
PubMed: 38510959
DOI: 10.3389/fcimb.2024.1378094 -
Fish & Shellfish Immunology May 2024The global aquaculture industry has significant losses each year due to disease outbreaks. Antibiotics are one of the common methods to treat fish infections, but...
The global aquaculture industry has significant losses each year due to disease outbreaks. Antibiotics are one of the common methods to treat fish infections, but prolonged use can lead to the emergence of resistant strains. Aeromonas spp. Infections are a common and problematic disease in fish, and members of this genera can produce antibiotic resistant strains. Antimicrobial peptides (AMPs) have emerged as an alternative method to treat and prevent infections and pituitary adenylate cyclase activating polypeptide (PACAP) is a prominent member of this family. The objective of this research was to study PACAP's direct antimicrobial activity and its toxicity in fish cells. Four synthetic variants of the natural PACAP from Clarias gariepinus were tested in addition to the natural variant. The experimental results show a different antimicrobial activity against A. salmonicida and A. hydrophila of each PACAP variant, and for the first time show dependence on the culture broth used. Furthermore, the results suggest that the underlying mechanism of PACAP antimicrobial activity includes a bacterial membrane permeabilizing effect, classifying PACAP as a membrane disruptive AMP. This study also demonstrated that the five PACAP variants evaluated showed low toxicity in vitro, at concentrations relevant for in vivo applications. Therefore, PACAP could be a promising alternative to antibiotics in the aquaculture sector.
Topics: Animals; Pituitary Adenylate Cyclase-Activating Polypeptide; Bacteria; Anti-Infective Agents; Anti-Bacterial Agents; Aquaculture
PubMed: 38499216
DOI: 10.1016/j.fsi.2024.109512 -
Frontiers in Immunology 2024, a gram-negative coccobacillus bacterium, can cause various infections in humans, including septic arthritis, diarrhea (traveler's diarrhea), gastroenteritis, skin and...
, a gram-negative coccobacillus bacterium, can cause various infections in humans, including septic arthritis, diarrhea (traveler's diarrhea), gastroenteritis, skin and wound infections, meningitis, fulminating septicemia, enterocolitis, peritonitis, and endocarditis. It frequently occurs in aquatic environments and readily contacts humans, leading to high infection rates. This bacterium has exhibited resistance to numerous commercial antibiotics, and no vaccine has yet been developed. Aiming to combat the alarmingly high infection rate, this study utilizes techniques to design a multi-epitope vaccine (MEV) candidate against this bacterium based on its aerolysin toxin, which is the most toxic and highly conserved virulence factor among the species. After retrieval, aerolysin was processed for B-cell and T-cell epitope mapping. Once filtered for toxicity, antigenicity, allergenicity, and solubility, the chosen epitopes were combined with an adjuvant and specific linkers to create a vaccine construct. These linkers and the adjuvant enhance the MEV's ability to elicit robust immune responses. Analyses of the predicted and improved vaccine structure revealed that 75.5%, 19.8%, and 1.3% of its amino acids occupy the most favored, additional allowed, and generously allowed regions, respectively, while its ERRAT score reached nearly 70%. Docking simulations showed the MEV exhibiting the highest interaction and binding energies (-1,023.4 kcal/mol, -923.2 kcal/mol, and -988.3 kcal/mol) with TLR-4, MHC-I, and MHC-II receptors. Further molecular dynamics simulations demonstrated the docked complexes' remarkable stability and maximum interactions, i.e., uniform RMSD, fluctuated RMSF, and lowest binding net energy. models also predict the vaccine will stimulate a variety of immunological pathways following administration. These analyses suggest the vaccine's efficacy in inducing robust immune responses against . With high solubility and no predicted allergic responses or toxicity, it appears safe for administration in both healthy and -infected individuals.
Topics: Humans; Artificial Intelligence; Aeromonas hydrophila; Diarrhea; Travel; Machine Learning; Vaccines; Epitopes, T-Lymphocyte; Adjuvants, Immunologic; Adjuvants, Pharmaceutic; Bacterial Toxins; Pore Forming Cytotoxic Proteins
PubMed: 38495891
DOI: 10.3389/fimmu.2024.1369890 -
BMC Veterinary Research Mar 2024In the present study, Aeromonas hydrophila was isolated from Tilapia zillii and Mugil cephalus samples collected during different seasons from various Suez Canal areas...
In the present study, Aeromonas hydrophila was isolated from Tilapia zillii and Mugil cephalus samples collected during different seasons from various Suez Canal areas in Egypt. The prevalence of A. hydrophila, virulence genes, and antibiotic resistance profile of the isolates to the commonly used antibiotics in aquaculture were investigated to identify multiple drug resistance (MDR) and extensive drug-resistant (XDR) strains. In addition, a pathogenicity test was conducted using A. hydrophila, which was isolated and selected based on the prevalence of virulence and resistance genes, and morbidity of natural infected fish. The results revealed that A. hydrophila was isolated from 38 of the 120 collected fish samples (31.6%) and confirmed phenotypically and biochemically. Several virulence genes were detected in retrieved A. hydrophila isolates, including aerolysin aerA (57.9%), ser (28.9%), alt (26.3%), ast (13.1%), act (7.9%), hlyA (7.9%), and nuc (18.4%). Detection of antibiotic-resistant genes revealed that all isolates were positive for bla (100%), bla (42.1%), tetA (60.5%), and sul1 (42.1%). 63.1% of recovered isolates were considered MDR, while 28.9% of recovered isolates were considered XDR. Some isolates harbor both virulence and MDR genes; the highest percentage carried 11, followed by isolates harboring 9 virulence and resistance genes. It could be concluded that the high prevalence of A. hydrophila in aquaculture species and their diverse antibiotic resistance and virulence genes suggest the high risk of Aeromonas infection and could have important implications for aquaculture and public health.
Topics: Animals; Aeromonas hydrophila; Tilapia; Anti-Bacterial Agents; Drug Resistance, Microbial; Drug Resistance, Multiple
PubMed: 38459543
DOI: 10.1186/s12917-024-03942-y -
Microbiology Spectrum Apr 2024, an aquatic pathogenic bacterium, has been found to infect many fish species and cause huge aquaculture losses. Antibiotics are the most common drugs used to treat...
, an aquatic pathogenic bacterium, has been found to infect many fish species and cause huge aquaculture losses. Antibiotics are the most common drugs used to treat these infections. However, antibiotic abuse can lead to the development of antibiotic resistance. Probiotics have the potential to replace antibiotics for preventing infections. Zebrafish () is a model organism used to study the innate immune system and host-pathogen interactions. Currently, there is little information on how the fish immune system responds to and probiotic treatment. To increase the understanding of the molecular mechanisms behind the zebrafish defense against and provide evidence that antibiotics can be replaced by probiotics, a transcriptome analysis of the zebrafish spleen was conducted 48 hours after infection by , as well as after treatment using KUST48 4 hours after infection. A total of 36,499 genes were obtained. There were 3,337 genes found to have significant differential expression between treatment and control groups. According to further annotation and enrichment analysis, differentially expressed genes (DEGs) were involved in signal transduction, endocrine system cancer, and the immune system. Insulin resistance disappeared in the zebrafish after treatment. Quantitative real-time PCR was performed to confirm the significant regulation of immune defense DEGs, the results of which were consistent with the RNA-sequencing data. These results could serve as a basis for future studies on the immune response to and provide suggestions for probiotic alternatives to antibiotics, which will be of great significance to aquaculture and environmental protection.IMPORTANCEIn recent years, the unreasonable use of antibiotics has led to the emergence of drug-resistant pathogenic bacteria, antibiotic residues, cross infection, toxic side effects, and so on, which has caused a serious threat to human food safety and life health. In recent years, many studies have demonstrated the potential of probiotics as a substitute for antibiotics, but there is still a lack of understanding of the molecular mechanisms underlying probiotic therapy. We conduct a research on the impact of KUST48 on the transcription profile of -infected zebrafish spleen. Mortality of zebrafish infected with was significantly reduced after treatment with KUST48. Our results can help to strengthen our understanding of the pathogenic mechanisms of zebrafish and provide a valuable reference for the molecular mechanisms of probiotic therapy.
Topics: Animals; Humans; Zebrafish; Aeromonas hydrophila; Lactococcus lactis; Spleen; Anti-Bacterial Agents; Gram-Negative Bacterial Infections; Fish Diseases
PubMed: 38441470
DOI: 10.1128/spectrum.03927-23 -
Antimicrobial Resistance and Infection... Mar 2024Aeromonas hydrophila infections can cause gastrointestinal symptoms such as diarrhea; however, deep infections are rarely reported. Outbreaks of A. hydrophila are...
BACKGROUND
Aeromonas hydrophila infections can cause gastrointestinal symptoms such as diarrhea; however, deep infections are rarely reported. Outbreaks of A. hydrophila are reported more frequently in fish, poultry, and snakes than in humans. This study aimed to track clonal relatedness of deep infections caused by A. hydrophila using whole genome sequencing (WGS).
METHODS
We collected three isolates of A. hydrophila in July 19 to August 29, 2019, from patients that underwent spine surgery. Accurate species identification was performed using whole-genome average nucleotide identity (ANI). Antimicrobial susceptibility testing was performed using a VITEK 2 automated AST-N334 Gram-negative susceptibility card system. Antimicrobial resistance and virulence genes were identified using the Comprehensive Antibiotic Resistance Database and Virulence Factor Database VFanalyzer.
RESULTS
All three isolates were identified as A. hydrophila based on ANI and multilocus sequence typing analysis revealed that A. hydrophila belonged to a novel sequence type (ST1172). All three isolates were susceptible to amikacin and levofloxacin; however, they were resistant to piperacillin/tazobactam, ceftriaxone, cefuroxime, cefoxitin, and imipenem. Isolate 19W05620 (patient 3) showed increased ceftazidime resistance (minimum inhibitory concentration ≥ 64 µg/mL). All three isolates possessed the same chromosomally encoded β-lactamases, including bla (β-lactamase), imiH (metallo-β-lactamase), and bla (AmpC) in plasmids.
CONCLUSIONS
Our study validated the transmission of a novel carbapenem-resistant A. hydrophila sequence type (ST1172) in patients that underwent spine surgery. Control measures should be developed to prevent dissemination of A. hydrophila in the hospital setting.
Topics: Animals; Humans; Aeromonas hydrophila; Amikacin; Carbapenems; beta-Lactamases; Anti-Infective Agents
PubMed: 38433212
DOI: 10.1186/s13756-023-01339-4