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Scientific Reports May 2023Aeromonas hydrophila is a ubiquitous fish pathogen and an opportunistic human pathogen. It is mostly found in aquatic habitats, but it has also been isolated from food...
Aeromonas hydrophila is a ubiquitous fish pathogen and an opportunistic human pathogen. It is mostly found in aquatic habitats, but it has also been isolated from food and bottled mineral waters. It causes hemorrhagic septicemia, ulcerative disease, and motile Aeromonas septicemia (MAS) in fish and other aquatic animals. Moreover, it might cause gastroenteritis, wound infections, and septicemia in humans. Different variables influence A. hydrophila virulence, including the virulence genes expressed, host susceptibility, and environmental stresses. The identification of virulence factors for a bacterial pathogen will help in the development of preventive and control measures. 95 Aeromonas spp. genomes were examined in the current study, and 53 strains were determined to be valid A. hydrophila. These genomes were examined for pan- and core-genomes using a comparative genomics technique. A. hydrophila has an open pan-genome with 18,306 total genes and 1620 genes in its core-genome. In the pan-genome, 312 virulence genes have been detected. The effector delivery system category had the largest number of virulence genes (87), followed by immunological modulation and motility genes (69 and 46, respectively). This provides new insight into the pathogenicity of A. hydrophila. In the pan-genome, a few distinctive single-nucleotide polymorphisms (SNPs) have been identified in four genes, namely: D-glycero-beta-D-manno-heptose-1,7-bisphosphate 7-phosphatase, chemoreceptor glutamine deamidase, Spermidine N (1)-acetyltransferase, and maleylpyruvate isomerase, which are present in all A. hydrophila genomes, which make them molecular marker candidates for precise identification of A. hydrophila. Therefore, for precise diagnostic and discrimination results, we suggest these genes be considered when designing primers and probes for sequencing, multiplex-PCR, or real-time PCR.
Topics: Animals; Humans; Aeromonas hydrophila; Virulence; Polymorphism, Single Nucleotide; Virulence Factors; Aeromonas; Fishes; Fish Diseases; Gram-Negative Bacterial Infections
PubMed: 37173388
DOI: 10.1038/s41598-023-34887-1 -
Scientific Reports Jul 2023The proliferation of antibiotic-resistant bacteria and antimicrobial resistance is a pressing public health challenge because of their possible transfer to humans via...
Isolation and genotypic characterization of extended-spectrum beta-lactamase-producing Escherichia coli O157:H7 and Aeromonas hydrophila from selected freshwater sources in Southwest Nigeria.
The proliferation of antibiotic-resistant bacteria and antimicrobial resistance is a pressing public health challenge because of their possible transfer to humans via contact with polluted water sources. In this study, three freshwater resources were assessed for important physicochemical characteristics as well as heterotrophic and coliform bacteria and as potential reservoirs for extended-spectrum beta-lactamase (ESBL) strains. The physicochemical characteristics ranged from 7.0 to 8.3; 25 to 30 °C, 0.4 to 93 mg/L, 0.53 to 8.80 mg/L and 53 to 240 mg/L for pH, temperature, dissolved oxygen (DO), biological oxygen demand (BOD) and total dissolved solids, respectively. The physicochemical characteristics mostly align with guidelines except for the DO and BOD in some instances. Seventy-six (76) Aeromonas hydrophila and 65 Escherichia coli O157: H7 isolates were identified by preliminary biochemical analysis and PCR from the three sites. Among these, A. hydrophila displayed higher frequencies of antimicrobial resistance, with all 76 (100%) isolates completely resistant to cefuroxime and cefotaxime and with MARI ≥ 0.61. The test isolates showed more than 80% resistance against five of the ten test antimicrobials, with resistance against cefixime, a cephalosporin antibiotic being the highest at 95% (134/141). The frequency of the detection of the resistance genes in the A. hydrophila isolates generally ranged between 0% (bla) and 26.3% (bla), while the frequency of detection among the E. coli O157:H7 isolates ranged between 4.6% (bla) and 58.4% (bla). Our findings indicate that the distribution of antibiotic-resistant bacteria with diverse ESBL-producing capabilities and virulence genes in freshwater sources potentially threatens public health and the environment.
Topics: Humans; Escherichia coli O157; Aeromonas hydrophila; Nigeria; beta-Lactamases; Anti-Bacterial Agents; Escherichia coli Infections; Anti-Infective Agents
PubMed: 37400612
DOI: 10.1038/s41598-023-38014-y -
Antimicrobial Agents and Chemotherapy Sep 2018The mobile colistin resistance gene is globally disseminated in both and species, with the latter potentially serving as a reservoir for this gene. Here, we...
The mobile colistin resistance gene is globally disseminated in both and species, with the latter potentially serving as a reservoir for this gene. Here, we investigated the prevalence of in rectal swabs from humans, in food-producing animals and their products, and in the aquatic environment, and we investigated the genetic relationships between the -positive isolates. An enriched broth screening method was used to detect in samples, and species identification of isolates from positive samples was carried out by matrix-assisted laser desorption ionization-time of flight mass spectrometry and shotgun sequencing. All -positive isolates were subjected to antimicrobial susceptibility testing, conjugation, and whole-genome sequencing. Ten isolates, including 2 from human rectal swabs, 1 from pork, 3 from chicken meat, and 4 from the aquatic environment, were positive for , but only 2 showed resistance to colistin. In addition to the variants identified previously (the novel variants were termed to ), all isolates harbored -like genes downstream of the variants. The MCR-3.13 to MCR-3.18 proteins exhibited only 89.2% to 96.1% amino acid identity to the original MCR-3 protein. Whole-genome sequence analysis indicated diversity within the genetic environments of -positive isolates and possible transmission between different sources in China and even worldwide. Close relationships between -positive and -negative isolates suggested that might be common in species, which are not inherent hosts of but may act as an important reservoir of this mobile colistin resistance gene.
Topics: Aeromonas; Animals; Anti-Bacterial Agents; Bacterial Proteins; Chickens; China; Drug Resistance, Bacterial; Enterobacteriaceae; Environment; Humans; Meat; Microbial Sensitivity Tests; Prevalence; Swine; Water; Water Microbiology; Whole Genome Sequencing
PubMed: 29967026
DOI: 10.1128/AAC.00404-18 -
International Journal of Molecular... Oct 2022species are opportunistic bacteria causing a vast spectrum of human diseases, including skin and soft tissue infections, meningitis, endocarditis, peritonitis,...
species are opportunistic bacteria causing a vast spectrum of human diseases, including skin and soft tissue infections, meningitis, endocarditis, peritonitis, gastroenteritis, and finally hemorrhagic septicemia. The aim of our research was to indicate the molecular alterations in proteins and lipids profiles resulting from and subsp. infection in trout kidney tissue samples. We successfully applied FT-IR (Fourier transform infrared) spectroscopy and MALDI-MSI (matrix-assisted laser desorption/ionization mass spectrometry imaging) to monitor changes in the structure and compositions of lipids, secondary conformation of proteins, and provide useful information concerning disease progression. Our findings indicate that the following spectral bands' absorbance ratios (spectral biomarkers) can be used to discriminate healthy tissue from pathologically altered tissue, for example, lipids (CH/CH), amide I/amide II, amide I/CH and amide I/CH. Spectral data obtained from 10 single measurements of each specimen indicate numerous abnormalities concerning proteins, lipids, and phospholipids induced by infection, suggesting significant disruption of the cell membranes. Moreover, the increase in the content of lysolipids such as lysophosphosphatidylcholine was observed. The results of this study suggest the application of both methods MALDI-MSI and FT-IR as accurate methods for profiling biomolecules and identifying biochemical changes in kidney tissue during the progression of infection.
Topics: Animals; Humans; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Lipidomics; Proteomics; Trout; Spectroscopy, Fourier Transform Infrared; Aeromonas; Phospholipids; Proteins; Biomarkers; Kidney; Amides
PubMed: 36293421
DOI: 10.3390/ijms232012551 -
PloS One 2021Assessments regarding health aspects of Iberian leuciscids are limited. There is currently an information gap regarding effects of infectious diseases on these...
Assessments regarding health aspects of Iberian leuciscids are limited. There is currently an information gap regarding effects of infectious diseases on these populations and their role as a possible conservation threat. Moreover, differences in susceptibility to particular agents, such as Aeromonas spp., by different species/populations is not clear. To understand potential differences in Aeromonas diversity and load, as well as in the prevalence and proportion of skin lesions, in fishes exposed to similar environmental conditions, an observational study was implemented. Using a set of 12 individuals belonging to two sympatric Iberian leuciscid species (Squalius pyrenaicus and Iberochondrostoma lusitanicum), the skin lesion score in each individual was analyzed. Furthermore, a bacterial collection of Aeromonas spp. isolated from each individual was created and isolates' load was quantified by plate counting, identified at species level using a multiplex-PCR assay and virulence profiles established using classical phenotypic methods. The similarity relationships of the isolates were evaluated using a RAPD analysis. The skin lesion score was significantly higher in S. pyrenaicus, while the Aeromonas spp. load did not differ between species. When analyzing Aeromonas species diversity between fishes, different patterns were observed. A predominance of A. hydrophila was detected in S. pyrenaicus individuals, while I. lusitanicum individuals displayed a more diverse structure. Similarly, the virulence index of isolates from S. pyrenaicus was higher, mostly due to the isolated Aeromonas species. Genomic typing clustered the isolates mainly by fish species and skin lesion score. Specific Aeromonas clusters were associated with higher virulence indexes. Current results suggest potential differences in susceptibility to Aeromonas spp. at the fish species/individual level, and constitute important knowledge for proper wildlife management through the signalization of at-risk fish populations and hierarchization of conservation measures.
Topics: Aeromonas; Random Amplified Polymorphic DNA Technique; Virulence
PubMed: 34352027
DOI: 10.1371/journal.pone.0255850 -
Frontiers in Cellular and Infection... 2021This prospective study aimed to investigate the clinical and microbiological characteristics of different species. Clinical isolates of species between 2016 to 2018...
Pancreaticobiliary Cancers and Aeromonas Isolates Carrying Type Ⅲ Secretion System Genes Are Associated With Increased Mortality: An Analysis of 164 Aeromonas Infection Episodes in Southern Taiwan.
This prospective study aimed to investigate the clinical and microbiological characteristics of different species. Clinical isolates of species between 2016 to 2018 were collected in a university hospital in southern Taiwan. The species was determined by or sequencing. A total of 222 isolates from 160 patients in 164 episodes were identified. The crude in-hospital mortality was 17.2%. The most frequently isolated species was (30.6%), followed by (24.8%), (23%), and (16.7%). The major clinical manifestations were primary bacteremia (31.1%), skin and soft tissue infection (22.6%), and biliary tract infection (18.3%). The most common underlying diseases were malignancy (45.1%), diabetes mellitus (27.4%), and liver cirrhosis or chronic hepatitis (26.2%). and predominated in the skin and soft tissue infection (p<0.0001), whereas and prevailed in primary bacteremia and biliary tract infections (p=0.012). Pneumonia, malignancy, and genotype were independent factors associated with mortality. Ertapenem susceptibility was decreased in (42.9%), (66.7%), (73%), and (84.3%). Cefotaxime resistance was found in 30.9% of and 18.9% of isolates, much more prevalent than the other species. The metallo-β-lactamase was almost invariably present in , , and (100%, 100% and 89.9%, respectively). Amp-C β-lactamases such as and were identified in all and 91.9% of isolates. Cefepime, fluoroquinolones and tigecycline showed good activity against aeromonads.
Topics: Aeromonas; Anti-Bacterial Agents; Gram-Negative Bacterial Infections; Humans; Neoplasms; Prospective Studies; Taiwan; Type III Secretion Systems
PubMed: 34737976
DOI: 10.3389/fcimb.2021.749269 -
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 -
Japanese Journal of Infectious Diseases Jan 2023In this study, Aeromonas spp. were re-identified, and the clinical aspects associated with Aeromonas bacteremia, as well as drug resistance and virulence genes, were...
Accurate Identification and Virulence Detection of Aeromonas: a Single-Center Retrospective Study on the Clinical Features and Outcomes Associated with Aeromonas Bacteremia in Southwestern China.
In this study, Aeromonas spp. were re-identified, and the clinical aspects associated with Aeromonas bacteremia, as well as drug resistance and virulence genes, were elucidated. A total of 188 isolates were classified into 7 Aeromonas spp. using housekeeping gene sequencing, which was the standard to assess the accuracy of the VITEK MALDI-TOF system and the VITEK2 Compact system. The VITEK MS system and housekeeping gene sequencing had a 39.89% clear coincidence rate, whereas the VITEK2 Compact system and the standard had a 2.13% coincidence rate. Aeromonas bacteremia was associated with septic shock, hematologic malignancy, and post-hepatitic cirrhosis. Hematological malignancy, hypoproteinemia, systemic steroid use, central venous catheterization, and virulence genes act and ast were linked to poor outcomes. Aeromonas bacteremia had a 37.5% mortality rate; however, differences in mortality rates among Aeromonas spp. were observed. According to the broth microdilution method, over 90% of isolates were sensitive to most antimicrobials, except ceftriaxone (83.33%) and imipenem (83.33%). Polymerase chain reaction and DNA sequencing verified the presence of drug resistance genes; bla was detected in 3 isolates, while bla was found in one isolate. In summary, common methods for identifying Aeromonas spp. are ineffective. Immunocompromised patients have a higher risk of infection and mortality. Furthermore, carbapenem resistance is a serious problem.
Topics: Humans; Aeromonas; Virulence; Retrospective Studies; Imipenem; Hematologic Neoplasms; Bacteremia; Anti-Bacterial Agents
PubMed: 36047178
DOI: 10.7883/yoken.JJID.2022.101 -
BMC Infectious Diseases Oct 2023Aeromonas hydrophila can cause a wide range of diseases and is mainly found in patients with underlying diseases. Globally the data on Aeromonas infections is limited,...
BACKGROUND
Aeromonas hydrophila can cause a wide range of diseases and is mainly found in patients with underlying diseases. Globally the data on Aeromonas infections is limited, and no studies have been published about the situation in Saudi Arabia. The aim of this study was to investigate the risk factors, clinical presentation, treatment, and outcomes of Aeromonas infections in Saudi Arabia.
METHODS
A retrospective study was performed at a tertiary university hospital with 1000 beds in Jeddah, Saudi Arabia. All patients 14 years and older with Aeromonas-positive cultures between January 1, 2015, and December 31, 2022 were included. Patient information was extracted from the electronic health records, including patient demographics, comorbidities, presenting symptoms, source of infection, human immunodeficiency virus status, culture results and antimicrobial susceptibility, use of immunosuppressive medication, and 30-day mortality.
RESULTS
In total 24 patients were identified with Aeromonas hydrophila-positive cultures, 22 of which were males (91.7%), and most (75%) had hospital-acquired infections. The 30-day mortality was 20.8%. All Aeromonas cultures were susceptible to gentamicin, cefepime, and ciprofloxacin, while the majority were resistant to ceftazidime (83.3%) and meropenem (62.5%). The most common disease presentation was skin and soft tissue infection (33.3%), the most common clinical sign was fever (58.3%), and the most common symptom was abdominal pain (37.5%). Comorbidities were very common (median 3, range 1-7). Pitt bacteremia score (p < 0.001), Charlson weighted comorbidity index (p < 0.02), international normalized ratio (p < 0.005), and the number of comorbidity factors (p < 0.05) were all associated with 30-day mortality due to Aeromonas infection. The number of comorbidities had the best predictive value (83.3%) of 30-day mortality (p < 0.05, Odds ratio 3.253, 95% confidence interval: 1.088-9.729).
CONCLUSIONS
Aeromonas hydrophila is an important pathogen to consider in nosocomial infections. The number of comorbidities had the best predictive value of 30-day mortality. The susceptibility pattern of this organism indicates that, in Saudi Arabia, when an Aeromonas infection is suspected, treatment with quinolone along with other broad-spectrum antibiotics should be started until the culture and susceptibility results are known.
Topics: Male; Humans; Female; Aeromonas hydrophila; Retrospective Studies; Tertiary Care Centers; Saudi Arabia; Anti-Bacterial Agents; Aeromonas
PubMed: 37814215
DOI: 10.1186/s12879-023-08660-8 -
Journal of Applied Microbiology Sep 2018The phylogenies derived from housekeeping gene sequence alignments, although mere evolutionary hypotheses, have increased our knowledge about the Aeromonas genetic... (Review)
Review
The phylogenies derived from housekeeping gene sequence alignments, although mere evolutionary hypotheses, have increased our knowledge about the Aeromonas genetic diversity, providing a robust species delineation framework invaluable for reliable, easy and fast species identification. Previous classifications of Aeromonas, have been fully surpassed by recently developed phylogenetic (natural) classification obtained from the analysis of so-called 'molecular chronometers'. Despite ribosomal RNAs cannot split all known Aeromonas species, the conserved nature of 16S rRNA offers reliable alignments containing mosaics of sequence signatures which may serve as targets of genus-specific oligonucleotides for subsequent identification/detection tests in samples without culturing. On the contrary, some housekeeping genes coding for proteins show a much better chronometric capacity to discriminate highly related strains. Although both, species and loci, do not all evolve at exactly the same rate, published Aeromonas phylogenies were congruent to each other, indicating that, phylogenetic markers are synchronized and a concatenated multigene phylogeny, may be 'the mirror' of the entire genomic relationships. Thanks to MLPA approaches, the discovery of new Aeromonas species and strains of rarely isolated species is today more frequent and, consequently, should be extensively promoted for isolate screening and species identification. Although, accumulated data still should be carefully catalogued to inherit a reliable database.
Topics: Aeromonas; Bacterial Typing Techniques; DNA, Bacterial; Genes, Bacterial; Genes, Essential; Phylogeny
PubMed: 29676027
DOI: 10.1111/jam.13887