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Proceedings of the National Academy of... Nov 2019An earlier report described a human case of necrotizing fasciitis (NF) caused by mixed infection with 4 strains (NF1-NF4). While the NF2, NF3, and NF4 strains were...
An earlier report described a human case of necrotizing fasciitis (NF) caused by mixed infection with 4 strains (NF1-NF4). While the NF2, NF3, and NF4 strains were clonal and possessed exotoxin A (ExoA), the NF1 strain was determined to be phylogenetically distinct, harboring a unique type 6 secretion system (T6SS) effector (TseC). During NF1 and NF2 mixed infection, only NF1 disseminated, while NF2 was rapidly killed by a contact-dependent mechanism and macrophage phagocytosis, as was demonstrated by using in vitro models. To confirm these findings, we developed 2 NF1 mutants (NF1Δ and NF1Δ); encodes an essential T6SS structural component. NF1 VasK and TseC were proven to be involved in contact-dependent killing of NF2 in vitro, as well as in its elimination at the intramuscular injection site in vivo during mixed infection, with overall reduced mouse mortality. ExoA was shown to have an important role in NF by both NF1- (with ) and NF2 during monomicrobial infection. However, the contribution of ExoA was more important for NF2 than NF1 in the murine peritonitis model. The NF2∆ mutant did not significantly alter animal mortality or NF1 dissemination during mixed infection in the NF model, suggesting that the ExoA activity was significant at the injection site. Immunization of mice to ExoA protected animals from NF2 monomicrobial challenge, but not from polymicrobial infection because of NF2 clearance. This study clarified the roles of T6SS and ExoA in pathogenesis caused by NF strains in both mouse peritonitis and NF models in monomicrobial and polymicrobial infections.
Topics: Aeromonas hydrophila; Animals; Bacterial Toxins; Coinfection; Exotoxins; Fasciitis, Necrotizing; Humans; Metagenome; Mice; Peritonitis; Phagocytosis; Type VI Secretion Systems; Virulence
PubMed: 31712444
DOI: 10.1073/pnas.1914395116 -
Journal of Medical Case Reports Mar 2024Aeromonas veronii is a very rare and highly pathogenic microorganism. We investigate the clinical characteristics and significance of endogenous endophthalmitis caused...
BACKGROUND
Aeromonas veronii is a very rare and highly pathogenic microorganism. We investigate the clinical characteristics and significance of endogenous endophthalmitis caused by Aeromonas veronii in our patient.
CASE PRESENTATION
A 30-year-old Asian women with systemic lupus erythematosus, uremia, and hypertension developed acute infectious endophthalmitis caused by Aeromonas veronii. After emergency vitrectomy and antibiotic therapy, the clinical condition worsened requiring enucleation.
CONCLUSIONS
Aeromonas veronii can cause infection in the human eye, which can manifest as acute endophthalmitis. Early diagnosis and targeted therapy are important for successful treatment.
Topics: Humans; Female; Adult; Aeromonas veronii; Endophthalmitis; Anti-Bacterial Agents; Vitrectomy; Aeromonas; Gram-Negative Bacterial Infections
PubMed: 38504363
DOI: 10.1186/s13256-024-04412-7 -
BioMed Research International 2020Aeromonads are natural inhabitants of aquatic environments and may be associated with various human or animal diseases. Its pathogenicity is complex and multifactorial...
Aeromonads are natural inhabitants of aquatic environments and may be associated with various human or animal diseases. Its pathogenicity is complex and multifactorial and is associated with many virulence factors. In this study, 110 selected isolates isolated from food, animals, and human clinical material from 2010 to 2015 were analyzed. Antimicrobial susceptibility testing was performed by the disk diffusion method, and polymerase chain reaction was conducted to investigate the virulence genes hemolysin (A), cytotoxic enterotoxin (), heat-labile cytotonic enterotoxin (), aerolysin (A), and DNase-nuclease (). At least 92.7% of the isolates had one of the investigated virulence genes. Twenty different virulence profiles among the isolates were recognized, and the five investigated virulence genes were observed in four isolates. Human source isolates showed greater diversity than food and animal sources. Antimicrobial resistance was observed in 46.4% of the isolates, and multidrug resistance was detected in 3.6% of the isolates. Among the 120 isolates, 45% were resistant to cefoxitin; 23.5% to nalidixic acid; 16.6% to tetracycline; 13.7% to cefotaxime and imipenem; 11.8% to ceftazidime; 5.9% to amikacin, gentamicin, and sulfamethoxazole-trimethoprim; and 3.9% to ciprofloxacin and nitrofurantoin. Overall, the findings of our study indicated the presence of virulence genes and that antimicrobial resistance in . isolates in this study is compatible with potentially pathogenic bacteria. This information will allow us to recognize the potential risk through circulating isolates in animal health and public health and the spread through the food chain offering subsidies for appropriate sanitary actions.
Topics: Aeromonas hydrophila; Animals; Anti-Infective Agents; Bacterial Toxins; Brazil; Drug Resistance, Bacterial; Enterotoxins; Food Microbiology; Humans; Pore Forming Cytotoxic Proteins; Public Health; Virulence; Virulence Factors
PubMed: 32461959
DOI: 10.1155/2020/1052607 -
Carbohydrate Research Apr 2022Presented herein is the synthesis of the Aeromonas veronii disaccharide repeating unit which has been achieved in 11 steps starting from d-fucose and d-galactosamine.
Presented herein is the synthesis of the Aeromonas veronii disaccharide repeating unit which has been achieved in 11 steps starting from d-fucose and d-galactosamine.
Topics: Aeromonas; Aeromonas veronii; Disaccharides; Fucose
PubMed: 35263695
DOI: 10.1016/j.carres.2022.108530 -
International Journal of Food... Dec 2020Bagged, pre-cut and prewashed lettuce products are marketed as ready to eat. This concept poses a food safety concern, due to lack of efficient hurdles to eliminate...
Bagged, pre-cut and prewashed lettuce products are marketed as ready to eat. This concept poses a food safety concern, due to lack of efficient hurdles to eliminate possible microbial contaminants from the fresh produce and/or the processing itself. Aeromonas spp. are potential foodborne pathogens that are frequently isolated from lettuce. High counts of, e.g., A. hydrophila have been found in retail ready-to-eat (RTE) vegetable salads. The aim of this study was to assess the general microbiological quality, the occurrence and diversity of potential human pathogenic mesophilic Aeromonas spp. of retail RTE lettuce products. Additionally, temperature-dependent growth kinetic parameters of Aerobic Plate Counts (APC) and Aeromonas spp. in one selected RTE lettuce product, rocket lettuce, were quantified by performing storage experiments at 4 °C, 8 °C and 12 °C. The Aeromonas isolates were further characterized regarding pathogenic traits and phylogenetic relationship. The overall hygienic quality of the lettuce products was unsatisfactory, as 60% of the products had an APC level higher than 7.0 log CFU/g. Presumptive Aeromonas spp. were detected in 52% of the samples, levels ranging from approximately 2.0-6.0 log CFU/g. Significantly lower counts of APC and Aeromonas spp. were found in uncut and unwashed products. Presumptive Aeromonas spp. were able to proliferate in rocket lettuce stored at 4 °C (μ = 0.39 ± 0.06/d and μ = 0.43 ± 0.05/d for lettuce from producers A and B, respectively), and μ was approximately 2× higher at 8 °C and 3× higher at 12 °C. Eighty-four percent of the collected isolates were identified as A. media, based on partial gyrB sequencing. Additionally A. salmonicida and A. bestiarum were detected. The pathogenic potential in this material was high, most of the isolates harbored at least one of the toxin genes, act, ast, alt.
Topics: Aeromonas; Colony Count, Microbial; Fast Foods; Food Contamination; Food Microbiology; Food Storage; Lactuca; Norway; Phylogeny; Temperature; Vegetables; Virulence Factors
PubMed: 32932210
DOI: 10.1016/j.ijfoodmicro.2020.108852 -
MicrobiologyOpen Nov 2019Aeromonas is recognized as a human pathogen following ingestion of contaminated food and water. One major problem in Aeromonas identification is that certain species are...
Proteomic characterization and discrimination of Aeromonas species recovered from meat and water samples with a spotlight on the antimicrobial resistance of Aeromonas hydrophila.
Aeromonas is recognized as a human pathogen following ingestion of contaminated food and water. One major problem in Aeromonas identification is that certain species are phenotypically very similar. The antimicrobial resistance is another significant challenge worldwide. We therefore aimed to use mass spectrometry technology for identification and discrimination of Aeromonas species and to screen the antimicrobial resistance of Aeromonas hydrophila (A. hydrophila). A total of 150 chicken meat and water samples were cultured, and then, the isolates were identified biochemically by the Vitek 2 Compact system. Proteomic identification was performed by MALDI-TOF MS and confirmed by a microchannel fluidics electrophoresis assay. Principal component analysis (PCA) and single-peak analysis created by MALDI were also used to discriminate the Aeromonas species. The antimicrobial resistance of the A. hydrophila isolates was determined by Vitek 2 AST cards. In total, 43 samples were positive for Aeromonas and comprised 22 A. hydrophila, 12 Aeromonas caviae (A. caviae), and 9 Aeromonas sobria (A. sobria) isolates. Thirty-nine out of 43 (90.69%) Aeromonas isolates were identified by the Vitek 2 Compact system, whereas 100% of the Aeromonas isolates were correctly identified by MALDI-TOF MS with a score value ≥2.00. PCA successfully separated A. hydrophila, A. caviae and A. sobria isolates into two groups. Single-peak analysis revealed four discriminating peaks that separated A. hydrophila from A. caviae and A. sobria isolates. The resistance of A. hydrophila to antibiotics was 95.46% for ampicillin, 50% for cefotaxime, 45.45% for norfloxacin and pefloxacin, 36.36% for ceftazidime and ciprofloxacin, 31.81% for ofloxacin and 27.27% for nalidixic acid and tobramycin. In conclusion, chicken meat and water were tainted with Aeromonas spp., with a high occurrence of A. hydrophila. MALDI-TOF MS is a powerful technique for characterizing aeromonads at the genus and species levels. Future studies should investigate the resistance of A. hydrophila to various antimicrobial agents.
Topics: Aeromonas; Aeromonas caviae; Aeromonas hydrophila; Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Typing Techniques; Chickens; Drug Resistance, Bacterial; Humans; Meat; Microbial Sensitivity Tests; Proteome; Proteomics; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Water Microbiology
PubMed: 30614207
DOI: 10.1002/mbo3.782 -
Microbiology (Reading, England) May 2021The bacterial species is a fish pathogen. Feared by fish farmers everywhere on Earth over the past century, this species has turned out to be more diverse than...
The bacterial species is a fish pathogen. Feared by fish farmers everywhere on Earth over the past century, this species has turned out to be more diverse than initially suspected. While some psychrophilic subspecies cannot grow at temperatures above 25 °C or 30 °C, other mesophilic strains growing up to 37 °C and above are now characterized. Adding to the surprising diversity of this species, some of the mesophilic strains infect mammals and birds. The remarkable diversity is explained in part by the presence of numerous mobile genetic elements, which sculpt and modify the genome of the various strains of this species.
Topics: Aeromonas salmonicida; Animals; Biodiversity; DNA Transposable Elements; Fish Diseases; Fishes; Gram-Negative Bacterial Infections; Temperature
PubMed: 33945463
DOI: 10.1099/mic.0.001052 -
Carbohydrate Research Sep 2023The present study included three Aeromonas sp. strains isolated from fish tissues during Motile Aeromonas Infection/Motile Aeromonas Septicaemia disease outbreaks on...
Immunochemical studies and gene cluster relationships of closely related O-antigens of Aeromonas hydrophila Pt679, Aeromonas popoffii A4, and Aeromonas sobria K928 strains classified into the PGO1 serogroup dominant in Polish aquaculture of carp and rainbow trout.
The present study included three Aeromonas sp. strains isolated from fish tissues during Motile Aeromonas Infection/Motile Aeromonas Septicaemia disease outbreaks on commercial farms, i.e.: Aeromonas hydrophila Pt679 obtained from rainbow trout as well as Aeromonas popoffii A4 (formerly Aeromonas encheleia) and Aeromonas sobria K928 both isolated from carp, which were classified into the new provisional PGO1 serogroup prevailing among aeromonads in Polish aquaculture. The structure of the O-specific polysaccharides of A4 and K928 has been previously established. Here, immunochemical studies of the O-specific polysaccharide of A. hydrophila Pt679 were undertaken. The O-specific polysaccharide was obtained from the lipopolysaccharide of A. hydrophila Pt679 after mild acid hydrolysis and separation by gel-permeation chromatography. The high-molecular-mass fraction was studied using chemical methods and H and C NMR spectroscopy, including H,H NOESY, and H,C HMBC experiments. The following structure of the branched repeating unit of the O-polysaccharide from A. hydrophila Pt679 was determined: [Formula: see text] The studies indicated that O-polysaccharides from A. hydrophila Pt679, A. popoffii A4 and A. sobria K928 share similarities but they also contain unique characteristics. Western blotting and an enzyme-linked immunosorbent assay revealed that the cross-reactivity of the related O-antigens is caused by the occurrence of common structural elements, whereas additional epitopes define the specificity of the O-serotypes. For genetic relationship studies, the O-antigen gene cluster was characterized in the genome of the A. hydrophila Pt679 strain and compared with the corresponding sequences of A. popoffii A4 and A. sobria K928 and with sequences available in the databases. The composition of the regions was found to be consistent with the O-antigen structures of Aeromonas strains classified into the same PGO1 serogroup.
Topics: Animals; O Antigens; Aeromonas hydrophila; Oncorhynchus mykiss; Serogroup; Carps; Poland; Aeromonas; Aquaculture
PubMed: 37437416
DOI: 10.1016/j.carres.2023.108896 -
Viruses Nov 2022is a zoonotic pathogen and an important fish pathogen. A new lytic phage, Ahy-yong1, against multi-antibiotic-resistant pathogen was isolated, identified, and...
is a zoonotic pathogen and an important fish pathogen. A new lytic phage, Ahy-yong1, against multi-antibiotic-resistant pathogen was isolated, identified, and tentatively used in therapy. Ahy-yong1 possesses a head of approximately 66 nm in diameter and a short tail of approximately 26 nm in length and 32 nm in width. Its complete dsDNA genome is 43,374 bp with a G + C content of 59.4%, containing 52 predicted opening reading frames (ORFs). Taxonomic analysis indicated Ahy-yong1 as a new species of the genus of the family of the class. Ahy-yong1 was active only against its indicator host strain among the 35 strains tested. It is stable at 30-40 °C and at pH 2-12. phage Ahy-yong1 revealed an effective biofilm removal capacity and an obvious protective effect in brocade carp ( Koi). The average cumulative mortality for the brocade carp in the blank groups intraperitoneally injected with PBS was 1.7% ± 2.4%;for the control groups treated with (10 CFU/fish) via intraperitoneal injection, it was 100.00%;and for the test group I, successively treated with (10 CFU/fish) and phage Ahy-yong1 (10 PFU/fish) via intraperitoneal injection witha time interval of 2 hours, it was only 43.4% ± 4.7%. Furthermore, the cumulative mortality of the test group II, successively treated with phage Ahy-yong1 (10 PFU/fish) and (10 CFU/fish), was only 20.0% ± 8.2%, and that of the test group III, simultaneously treated with phage Ahy-yong1 (10 PFU/fish) and (10 CFU/fish), was only 30.0% ± 8.2%. The results demonstrated that phage Ahy-yong1 was very effective in the therapies against A18, prophylaxis was more effective than rescue, and earlier treatment was better for the reduction of mortality. This study enriches knowledge about phages.
Topics: Animals; Aeromonas hydrophila; Aeromonas; Carps; Bacteriophages; Caudovirales
PubMed: 36423108
DOI: 10.3390/v14112498 -
BMC Microbiology Jun 2018Iron plays important roles in the growth, reproduction and pathogenicity of Aeromonas hydrophila. In this study, we detected and compared the mRNA and protein expression... (Comparative Study)
Comparative Study
BACKGROUND
Iron plays important roles in the growth, reproduction and pathogenicity of Aeromonas hydrophila. In this study, we detected and compared the mRNA and protein expression profiles of A. hydrophila under normal and iron restricted medium with 200 μM 2,2-Dipyridyl using RNA Sequencing (RNA-seq) and isobaric tags for relative and absolute quantification (iTRAQ) analyses.
RESULTS
There were 1204 genes (601 up- and 603 down-regulated) and 236 proteins (90 up- and 146 down-regulated) shown to be differentially expressed, and 167 genes and proteins that showed consistent expression. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the differentially expressed genes and proteins were mainly involved in iron ion transport, protein activity, energy metabolism and virulence processes. Further validation of the RNA-seq and iTRAQ results by quantitative real-time PCR (qPCR) revealed that 18 of the 20 selected genes were consistently expressed. The iron-ion absorption and concentration of A. hydrophila under iron-limited conditions were enhanced, and most virulence factors (protease activity, hemolytic activity, lipase activity, and swimming ability) were also increased. Artificial A. hydrophila infection caused higher mortality in cyprinid Megalobrama amblycephala under iron-limited conditions.
CONCLUSION
Understanding the responses of pathogenic Aeromonas hydrophila within the hostile environment of the fish host, devoid of free iron, is important to reveal bacterial infection and pathogenesis. This study further confirmed the previous finding that iron-limitation efficiently enhanced the virulence of A. hydrophila using multi-omics analyses. We identified differentially expressed genes and proteins, related to enterobactin synthesis and virulence establishment, that play important roles in addressing iron scarcity.
Topics: Aeromonas hydrophila; Animals; Bacterial Proteins; Cyprinidae; Energy Metabolism; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Iron; Proteomics; Sequence Analysis, RNA; Up-Regulation; Virulence Factors
PubMed: 29866030
DOI: 10.1186/s12866-018-1178-8