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Fish & Shellfish Immunology Nov 2023There is a long-standing debate on the attributes of temperature for fish health. We recently showed that thermoregulatory programs exerted through natural behavioural...
There is a long-standing debate on the attributes of temperature for fish health. We recently showed that thermoregulatory programs exerted through natural behavioural fever drive molecular and cellular responses that contribute to pathogen clearance, inflammation control, and tissue repair. These offered a mechanistic basis for the survival advantage conferred through fever. Herein, we show the attributes of mechanical replication of this fever response. Central to our approach was consideration of both, the maximal temperatures naturally selected by fish after infection, as well as the dynamics of thermal changes induced through this response. Coarse replication of the febrile thermal program as well as shorter truncated thermal schedules offered immune-regulatory capacity. Most notably, these promoted induction of acute inflammation and significant enhancements to pathogen clearance. However, the coarse protocols tested only partially recapitulated enhancements to induction and control of tissue repair. Our findings highlight a promising new alternative to combat infections in fish using a natural, drug-free, sustainable approach.
Topics: Animals; Aeromonas veronii; Gram-Negative Bacterial Infections; Fishes; Inflammation; Fish Diseases; Aeromonas
PubMed: 37832750
DOI: 10.1016/j.fsi.2023.109157 -
Journal of Agricultural and Food... Nov 2023Lactic acid bacteria (LAB) were screened from (red sea bass), and their antimicrobial activities were evaluated against two species isolated from the , namely, (AV)...
Lactic acid bacteria (LAB) were screened from (red sea bass), and their antimicrobial activities were evaluated against two species isolated from the , namely, (AV) and (AJ). Three LAB isolates, MU8 (EF_8), MU2 (EFL_2), and MU9 (EFL_9), were found to inhibit both AV and AJ; however, their cell-free supernatant (CFS) did not do so. Interestingly, bacteriocin-like substances (BLS) induced by cocultures of EF_8 with AV exhibited the highest antimicrobial activity against both sp. The size of BLS was less than 1.0 kDa; the purified BLS were susceptible to proteinase K digestion, indicating that they are peptides. BLS contained 13 identified peptides derived from as determined by liquid chromatography-tandem mass spectrometry. Cocultures of Gram-positive-producing and -inducing LAB strains have been used to increase bacteriocin yields. To our knowledge, this is the first report describing inducible BLS produced by cocultures of Gram-positive-producing and Gram-negative-inducing strains.
Topics: Enterococcus faecium; Bacteriocins; Aeromonas veronii; Coculture Techniques; Aeromonas; Peptides; Anti-Infective Agents; Anti-Bacterial Agents
PubMed: 37779478
DOI: 10.1021/acs.jafc.3c04019 -
Clinical Microbiology Reviews Oct 1991Over the past decade, the emergence of Aeromonas species as bona fide human pathogens and their probable role as etiologic agents of bacterial gastroenteritis have... (Review)
Review
Over the past decade, the emergence of Aeromonas species as bona fide human pathogens and their probable role as etiologic agents of bacterial gastroenteritis have resulted in an explosion of scientific interest in the genus. Major accomplishments occurring in this field during that interval include a more refined taxonomy, identification of new cell-associated factors (surface layers, pili), and the molecular analysis of selected extracellular gene products that may play a critical role in pathogenesis (hemolysins, enterotoxins). This review provides an updated overview of recent systematic, clinical, and pathophysiologic advances and defines key areas of medical and scientific interest in which major questions remain unanswered.
Topics: Aeromonas; Animals; Gram-Negative Bacterial Infections; Humans; Syndrome; Virulence
PubMed: 1747858
DOI: 10.1128/CMR.4.4.397 -
Virology Nov 2023Aeromonas hydrophila, a Gram-negative pathogenic bacterium, is responsible for huge economic losses in aquaculture. In this study, we evaluated the efficacy of...
Aeromonas hydrophila, a Gram-negative pathogenic bacterium, is responsible for huge economic losses in aquaculture. In this study, we evaluated the efficacy of bacteriophage AHPMCC7 which was isolated by using A. hydrophila MTCC 1739 as a host. This bacteriophage exhibited 10 min latent period and burst size was 275. In liquid culture, bacteriophage AHPMCC7 could completely lyse A. hydrophila MTCC 1739 after 2 h. AHPMCC7 genome was 42,277 bp long with 58.9% G + C content. The genome consisted of 48 CDSs and no tRNA. The comparative genomic analyses clearly implied that AHPMCC7 might represent a novel species of the genus Aphunavirus under Autographiviridae family. Bacteriophage AHPMCC7 could survive at broad pH (3-10), temperature (4-37 °C), and salinity (0-40 ppt). In aquarium trial, AHPMCC7 could control A. hydrophila MTCC 1739 without affecting the survivability of Litopenaeus vannamei. Clearly, the bacteriophage AHPMCC7 might be used in shrimp aquaculture as a biocontrol agent.
Topics: Bacteriophages; Aeromonas; Aeromonas hydrophila; Caudovirales; Sequence Analysis
PubMed: 37774603
DOI: 10.1016/j.virol.2023.109887 -
FEMS Immunology and Medical Microbiology Apr 1997Most putative virulence determinants of Aeromonas species are chromosomally encoded. However, several recent reports have indicated that some may be carried on or...
Most putative virulence determinants of Aeromonas species are chromosomally encoded. However, several recent reports have indicated that some may be carried on or regulated by plasmids. Therefore, we examined the plasmid carriage rate of a total of 140 clinical and environmental Aeromonas isolates. Plasmid carriage was compared with the ability of an isolate to produce toxins and adhere to HEp-2 cells. Overall, plasmid incidence in Aeromonas species was low (23/140, 16%) and independent of the source of the isolate. Plasmids were, however, more common in environmental isolates of A. veronii biovar sobria than in clinical isolates of this species (P < 0.05). We could find no evidence to support the recent literature findings that plasmids may have a role in Aeromonas virulence.
Topics: Aeromonas; Bacterial Adhesion; Exotoxins; Plasmids; Virulence
PubMed: 9143879
DOI: 10.1111/j.1574-695X.1997.tb01015.x -
Microbial Drug Resistance (Larchmont,... Aug 2022and other closely related species cause motile aeromonad septicemia, a common fish disease. The disease affects many aquaculture sectors potentially requiring...
and other closely related species cause motile aeromonad septicemia, a common fish disease. The disease affects many aquaculture sectors potentially requiring antimicrobial treatments. Therefore, researchers and laboratory diagnosticians need criteria called epidemiological cutoff values (ECVs) to determine whether a bacterial isolate has developed decreased susceptibility to an antimicrobial. To generate ECVs for this bacterium, we assembled a diverse collection of 245 isolates previously identified as from fish. Using sequencing, we confirmed that 97 of the 245 isolates were . We allocated the isolates among three laboratories and tested their susceptibility against eight antimicrobials using standard Clinical and Laboratory Standards Institute (CLSI) disk diffusion and broth microdilution methods. The resulting frequency distributions were statistically analyzed to determine wild-type cutoff estimates, which, along with scatterplots, were used to estimate potential ECVs. In collaboration with the CLSI, aquaculture working group, we proposed ECVs for six of the eight antimicrobials tested. Subsequently, the CLSI Subcommittee on Veterinary Antimicrobial Susceptibility Testing reviewed our data and approved the ECVs to be added to the 2020 edition of the VET04 performance standards for antimicrobial susceptibility testing of aquatic bacteria.
Topics: Aeromonas; Aeromonas hydrophila; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Fishes; Microbial Sensitivity Tests
PubMed: 35972765
DOI: 10.1089/mdr.2021.0316 -
Microbiologia (Madrid, Spain) Feb 1993This review deals with several aspects of Aeromonas hydrophila and other motile Aeromonas species associated with foodborne illness. Although it is mainly dedicated to... (Review)
Review
This review deals with several aspects of Aeromonas hydrophila and other motile Aeromonas species associated with foodborne illness. Although it is mainly dedicated to the factors affecting growth and survival of this species in foods of animal origin, information on other topics is also provided. This paper includes sections on: Taxonomy, diseases caused by Aeromonas, virulence factors, reservoirs and prevalence in foods and water, factors affecting growth and survival, isolation and identification, and control measures.
Topics: Aeromonas; Aeromonas hydrophila; Animals; Animals, Domestic; Dairy Products; Disease Reservoirs; Environment; Food Contamination; Food Microbiology; Foodborne Diseases; Humans; Meat; Opportunistic Infections; Shellfish; Virulence; Water Microbiology
PubMed: 8484917
DOI: No ID Found -
Genome Biology and Evolution May 2020Aeromonads are ubiquitous aquatic bacteria that cause opportunistic infections in humans, but their pathogenesis remains poorly understood. A pathogenomic approach was... (Comparative Study)
Comparative Study
Aeromonads are ubiquitous aquatic bacteria that cause opportunistic infections in humans, but their pathogenesis remains poorly understood. A pathogenomic approach was undertaken to provide insights into the emergence and evolution of pathogenic traits in aeromonads. The genomes of 64 Aeromonas strains representative of the whole genus were analyzed to study the distribution, phylogeny, and synteny of the flanking sequences of 13 virulence-associated genes. The reconstructed evolutionary histories varied markedly depending on the gene analyzed and ranged from vertical evolution, which followed the core genome evolution (alt and colAh), to complex evolution, involving gene loss by insertion sequence-driven gene disruption, horizontal gene transfer, and paraphyly with some virulence genes associated with a phylogroup (aer, ser, and type 3 secretion system components) or no phylogroup (type 3 secretion system effectors, Ast, ExoA, and RtxA toxins). The general pathogenomic overview of aeromonads showed great complexity with diverse evolution modes and gene organization and uneven distribution of virulence genes in the genus; the results provided insights into aeromonad pathoadaptation or the ability of members of this group to emerge as pathogens. Finally, these findings suggest that aeromonad virulence-associated genes should be examined at the population level and that studies performed on type or model strains at the species level cannot be generalized to the whole species.
Topics: Adaptation, Physiological; Aeromonas; Biological Evolution; Genome, Bacterial; Genomics; Genotype; Humans; Phenotype; Phylogeny; Virulence; Virulence Factors
PubMed: 32196086
DOI: 10.1093/gbe/evaa055 -
PloS One 2019Aeromonas veronii is a gram-negative species abundant in aquatic environments that causes disease in humans as well as terrestrial and aquatic animals. In the current...
Aeromonas veronii is a gram-negative species abundant in aquatic environments that causes disease in humans as well as terrestrial and aquatic animals. In the current study, 41 publicly available A. veronii genomes were compared to investigate distribution of putative virulence genes, global dissemination of pathotypes, and potential mechanisms of virulence. The complete genome of A. veronii strain ML09-123 from an outbreak of motile aeromonas septicemia in farm-raised catfish in the southeastern United States was included. Dissemination of A. veronii strain types was discovered in dispersed geographical locations. Isolate ML09-123 is highly similar to Chinese isolate TH0426, suggesting the two strains have a common origin and may represent a pathotype impacting aquaculture in both countries. Virulence of strain ML09-123 in catfish in a dose-dependent manner was confirmed experimentally. Subsystem category disposition showed the majority of genomes exhibit similar distribution of genomic elements. The type I secretion system (T1SS), type II secretion system (T2SS), type 4 pilus (T4P), and flagellum core elements are conserved in all A. veronii genomes, whereas the type III secretion system (T3SS), type V secretion system (T5SS), type VI secretion system (T6SS), and tight adherence (TAD) system demonstrate variable dispersal. Distribution of mobile elements is dependent on host and geographic origin, suggesting this species has undergone considerable genetic exchange. The data presented here lends insight into the genomic variation of A. veronii and identifies a pathotype impacting aquaculture globally.
Topics: Aeromonas veronii; Animals; Aquaculture; Genomics; Gram-Negative Bacterial Infections; Humans; Virulence Factors; Water Microbiology
PubMed: 31465454
DOI: 10.1371/journal.pone.0221018 -
Antimicrobial Agents and Chemotherapy Jun 1986Mutants with multiple low-level antibiotic resistance were isolated from virulent wild-type Aeromonas salmonicida strains exposed to a low concentration of any one of...
Mutants with multiple low-level antibiotic resistance were isolated from virulent wild-type Aeromonas salmonicida strains exposed to a low concentration of any one of several low-molecular-mass (approximately 635 daltons or less) antibiotics. Multiple resistance was toward beta-lactam compounds (penicillin G, ampicillin, cloxacillin), quinolones (flumequine, oxolinic acid, nalidixic acid), tetracyclines, chloramphenicol, and novobiocin. Susceptibilities of the mutants toward several higher-molecular-mass (greater than 700 daltons) hydrophobic or polycationic antibiotics such as rifampin, erythromycin, polymyxin B, and streptomycin sulfate were not affected. The mutants were obtained at frequencies suggesting point mutations. Outer membrane protein profiles, examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, revealed that all multiple low-level resistant mutants were deficient in a major protein of approximately 38.5 kilodaltons and contained a major protein of approximately 37 kilodaltons which was not present in significant amounts in the wild-type strains. In addition, these mutants lacked exoprotease activity. Furthermore, mutants isolated as deficient in exoprotease were found, with the exception of one avirulent strain, to exhibit multiple low-level antibiotic resistance and the outer membrane protein changes.
Topics: Aeromonas; Anti-Bacterial Agents; Drug Resistance, Microbial; Electrophoresis, Polyacrylamide Gel; Mutation; Peptide Hydrolases
PubMed: 3524440
DOI: 10.1128/AAC.29.6.992