-
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 -
Journal of Food Protection Mar 2024Aquaponic production of fresh produce is a sustainable agricultural method becoming widely adopted, though few studies have investigated potential food safety hazards...
Aquaponic production of fresh produce is a sustainable agricultural method becoming widely adopted, though few studies have investigated potential food safety hazards within commercial systems. A longitudinal study was conducted to isolate and quantify several foodborne pathogens from a commercial, aquaponic farm, and to elucidate their distribution throughout. The survey was conducted over 2 years on a controlled-environment farm containing Nile tilapia (Oreochromis niloticus) and lettuce (Lactuca sativa). Samples (N = 1,047) were collected bimonthly from three identical, independent systems, and included lettuce leaves, roots, fingerlings (7-126 d old), feces from mature fish (>126 d old), water, and sponge swabs collected from the tank interior surface. Most probable number of generic Escherichia coli were determined using IDEXX Colilert Quanti-Tray. Enumeration and enrichment were used to detect Shiga toxin-producing E. coli (STEC), Salmonella enterica, Listeria monocytogenes, Aeromonas spp., Aeromonas hydrophilia, and Pseudomonas aeruginosa. Generic E. coli, STEC, L. monocytogenes, and S. enterica were not detected in collected samples. P. aeruginosa was isolated from water (7/351; 1.99%), swabs (3/351; 0.85%), feces (2/108; 1.85%), and lettuce leaves (2/99; 2.02%). A. hydrophila was isolated from all sample types (623/1047; 59.50%). The incidence of A. hydrophila in water (X = 23.234, p < 0.001) and sponge samples (X = 21.352, p < 0.001) increased over time.
Topics: Animals; Escherichia coli; Aeromonas hydrophila; Longitudinal Studies; Agriculture; Water
PubMed: 38278488
DOI: 10.1016/j.jfp.2024.100230 -
Journal of Visualized Experiments : JoVE Dec 2017Health monitoring systems are developed and used in zebrafish research facilities because pathogens of Danio rerio such as Aeromonas hydrophila, Mycobacterium spp., and...
Health monitoring systems are developed and used in zebrafish research facilities because pathogens of Danio rerio such as Aeromonas hydrophila, Mycobacterium spp., and Pseudocapillaria tomentosa have the potential to impair animal welfare and research. The fish are typically analyzed post mortem to detect microbes. The use of sentinels is a suggested way to improve the sensitivity of the surveillance and to reduce the number of animals to sample. The setting of a pre-filtration sentinel tank out of a recirculating system is described. The technique is developed to prevent water pollution and to represent the fish population by a careful selection of age, gender, and strains. In order to use the minimum number of animals, techniques to screen the environment are also detailed. Polymerase Chain Reaction (PCR) on surface sump swabs is used to significantly improve the detection of some prevalent and pathogenic mycobacterial species such as Mycobacterium fortuitum, Mycobacterium haemophilum, and Mycobacterium chelonae. Another environmental method consists of processing the sludge at the bottom of a holding tank or sump to look for P. tomentosa eggs. This is a cheap and fast technique that can be applied in quarantine where a breeding device is submerged into the holding tank of imported animals. Finally, PCR is applied to the sludge sample and A. hydrophila is detected at the sump's bottom and surface. Generally, these environmental screening techniques applied to these specific pathogens have led to an increased sensitivity compared to the testing of pre-filtration sentinels.
Topics: Aeromonas hydrophila; Animals; Fish Diseases; Mycobacterium; Trichuroidea; Zebrafish
PubMed: 29286459
DOI: 10.3791/55306 -
Tropical Medicine & International... Feb 2023Aeromonas spp. often cause life-threatening diseases, including necrotizing fasciitis, which may lead to septic shock and ultimately death. Aeromonas infections are...
OBJECTIVES
Aeromonas spp. often cause life-threatening diseases, including necrotizing fasciitis, which may lead to septic shock and ultimately death. Aeromonas infections are believed to be transmitted via minor wounds or the consumption of fresh fish. However, after the detection of Aeromonas hydrophila in ticks in areas endemic to Japanese-spotted fever (JSF), a novel transmission route of A. hydrophila (i.e., via tick bites) has been proposed. We investigated the prevalence of A. hydrophila in ticks in areas endemic and not endemic to JSF in the Mie Prefecture, Japan.
METHODS
We collected ticks from endemic and nonendemic areas in summer and winter and assessed them for presence of A. hydrophila using polymerase chain reaction.
RESULTS
Six A. hydrophila isolates were obtained from 95 ticks in endemic areas, whereas one A. hydrophila isolate was obtained from 142 ticks in non-endemic areas, in summer. All ticks that harboured A. hydrophila were Haemaphysalis longicornis (H.L); these ticks were almost at the larval stage and also carried Rickettsia spp. in the endemic area. In contrast, 51 and 41 ticks in the endemic and non-endemic areas were captured in winter, respectively; A. hydrophila was not detected in these.
CONCLUSIONS
This study revealed the prevalence of tick-borne A. hydrophila. Therefore, the risk of transmission of A. hydrophila via a tick bite should be considered in the following conditions: areas abundant in H. L. harbouring Rickettsia spp., in areas endemic for JSF, presence of ticks in the larval stage and during the summer season.
Topics: Animals; Aeromonas hydrophila; Larva; Rickettsia; Spotted Fever Group Rickettsiosis; Ticks
PubMed: 36579736
DOI: 10.1111/tmi.13847 -
MicrobiologyOpen Apr 2019Stress is an important contributing factor in the outbreak of infectious fish diseases. To comprehensively understand the impact of catecholamine stress hormone...
Stress is an important contributing factor in the outbreak of infectious fish diseases. To comprehensively understand the impact of catecholamine stress hormone norepinephrine (NE) on the pathogenicity of Aeromonas hydrophila, we assessed variations in bacterial growth, virulence-related genes expression and virulence factors activity after NE addition in serum-SAPI medium. Further, we assessed the effects of NE on A. hydrophila virulence in vivo by challenging fish with pathogenic strain AH196 and following with or without NE injection. The NE-associated stimulation of A. hydrophila strain growth was not linear-dose-dependent, and only 100 μM, or higher concentrations, could stimulate growth. Real-time PCR analyses revealed that NE notably changed 13 out of the 16 virulence-associated genes (e.g. ompW, ahp, aha, ela, ahyR, ompA, and fur) expression, which were all significantly upregulated in A. hydrophila AH196 (p < 0.01). NE could enhance the protease activity, but not affect the lipase activity, hemolysis, and motility. Further, the mortality of crucian carp challenged with A. hydrophila AH196 was significantly higher in the group treated with NE (p < 0.01). Collectively, our results showed that NE enhanced the growth and virulence of pathogenic bacterium A. hydrophila.
Topics: Aeromonas hydrophila; Animals; Bacterial Proteins; Carps; Fish Diseases; Gram-Negative Bacterial Infections; Hormones; Host-Pathogen Interactions; Norepinephrine; Stress, Physiological; Virulence
PubMed: 29897673
DOI: 10.1002/mbo3.664 -
Biochimica Et Biophysica Acta.... Oct 2020Pediocin PA-1 (PA-1) is a membrane-targeting bacteriocin from lactic acid bacteria, which shows antimicrobial activity against a wide range of Gram-positive pathogens....
Pediocin PA-1 (PA-1) is a membrane-targeting bacteriocin from lactic acid bacteria, which shows antimicrobial activity against a wide range of Gram-positive pathogens. However, the outer membrane of Gram-negative bacteria does not allow pediocin access to its target. In this work, the synergistic inhibitory mechanism of PA-1 with L-lactic acid against Gram-negative aquaculture and food pathogen Aeromonas hydrophila (A. hydrophila) was analyzed. The combined treatment of 3.5 mmol/L L-lactic acid and 50 μmol/L (or 30 μmol/L) PA-1 had strong bacteriostatic and bactericidal activity against A. hydrophila. Full wavelength scanning and ELISA assay revealed the release of lipopolysaccharide (LPS) from the outer membrane of A. hydrophila caused by L-lactic acid treatment. Laser confocal microscopic imaging of A. hydrophila with FITC-labeled pediocin PA-1 proved the accumulation of PA-1 on lactic acid-treated bacterial cells. PA-1 then caused a rapid dissipation of membrane potential (Δψ) and a proton gradient difference (ΔpH) in lactic acid-treated A. hydrophila. Pediocin PA-1 also caused an increase in the extracellular ATP level. Morphology revealed by SEM and TEM showed that combined treating with lactic acid and PA-1 induced vesicles on the cell surface, the outer and inner membrane disruption, and even cytoplasm leakage and cell lysis. The results proved a potential mechanism of the synergistic inhibition of lactic acid and PA-1 against A. hydrophila, by which L-lactic acid released the outer membrane LPS, making it possible for PA-1 to contact the plasma membrane of A. hydrophila, resulting in the dissipation of proton-motive force in the inner membrane and cell death.
Topics: Aeromonas hydrophila; Amino Acid Sequence; Anti-Bacterial Agents; Drug Synergism; Lactic Acid; Lipopolysaccharides; Microbial Sensitivity Tests; Pediocins
PubMed: 32428447
DOI: 10.1016/j.bbamem.2020.183346 -
Brazilian Journal of Biology = Revista... 2022Pakistan is an agricultural country and fisheries play a very important role in the economic development of the country. Different diseases are prevalent in Pakistani...
Pakistan is an agricultural country and fisheries play a very important role in the economic development of the country. Different diseases are prevalent in Pakistani fish but information related to the causative agents is not well-known. Keeping in view the significance of bacterial pathogens as the causative agents of multiple fish diseases, the present study was conducted for identification, characterization and analysis of virulence genes of Aeromonas spp. isolated from diseased fishes. A total of fifty fish samples having multiple clinical indications were collected from different fish farms of district Kasur, Punjab Pakistan. For isolation of Aeromonas spp. samples were enriched and inoculated on Aeromonas isolation medium. Isolates were identified and characterized by different biochemical tests, Analytical Profile Index (API) 20E kit and Polymerase Chain Reaction (PCR) assays. All isolates were screened for three putative virulence genes including aerolysin (aer), haemolysin (hyl) and heat labile cytotonic enterotoxin (alt). Seven isolates of Aeromonas (A.) hydrophila were retrieved and identified based on API 20E. These isolates were further confirmed as A. hydrophila on the basis of PCR assays. Three isolates were detected positive for the presence of virulence genes (alt and hyl). Whereas aerolysin (aer) gene was not present in any of A. hydrophila isolates. The present study confirmed A. hydrophila as the causative agent of epizootic ulcerative syndrome and motile Aeromonas septicemia in fish farms of district Kasur, Punjab Pakistan. Moreover, detection of two virulence genes (alt and hyl) in A. hydrophila isolates is a threat for fish consumers of study area.
Topics: Aeromonas; Aeromonas hydrophila; Animals; Enterotoxins; Fishes; Gram-Negative Bacterial Infections; Pakistan
PubMed: 35019106
DOI: 10.1590/1519-6984.254816 -
BMC Microbiology Jan 2021Hypervirulent Aeromonas hydrophila (vAh) is an emerging pathogen in freshwater aquaculture that results in the loss of over 3 million pounds of marketable channel...
BACKGROUND
Hypervirulent Aeromonas hydrophila (vAh) is an emerging pathogen in freshwater aquaculture that results in the loss of over 3 million pounds of marketable channel catfish, Ictalurus punctatus, and channel catfish hybrids (I. punctatus, ♀ x blue catfish, I. furcatus, ♂) each year from freshwater catfish production systems in Alabama, U.S.A. vAh isolates are clonal in nature and are genetically unique from, and significantly more virulent than, traditional A. hydrophila isolates from fish. Even with the increased virulence, natural infections cannot be reproduced in aquaria challenges making it difficult to determine modes of infection and the pathophysiology behind the devastating mortalities that are commonly observed. Despite the intimate connection between environmental adaptation and plastic response, the role of environmental adaption on vAh pathogenicity and virulence has not been previously explored. In this study, secreted proteins of vAh cultured as free-living planktonic cells and within a biofilm were compared to elucidate the role of biofilm growth on virulence.
RESULTS
Functional proteolytic assays found significantly increased degradative activity in biofilm secretomes; in contrast, planktonic secretomes had significantly increased hemolytic activity, suggesting higher toxigenic potential. Intramuscular injection challenges in a channel catfish model showed that in vitro degradative activity translated into in vivo tissue destruction. Identification of secreted proteins by HPLC-MS/MS revealed the presence of many putative virulence proteins under both growth conditions. Biofilm grown vAh produced higher levels of proteolytic enzymes and adhesins, whereas planktonically grown cells secreted higher levels of toxins, porins, and fimbrial proteins.
CONCLUSIONS
This study is the first comparison of the secreted proteomes of vAh when grown in two distinct ecological niches. These data on the adaptive physiological response of vAh based on growth condition increase our understanding of how environmental niche partitioning could affect vAh pathogenicity and virulence. Increased secretion of colonization factors and degradative enzymes during biofilm growth and residency may increase bacterial attachment and host invasiveness, while increased secretion of hemolysins, porins, and other potential toxins under planktonic growth (or after host invasion) could result in increased host mortality. The results of this research underscore the need to use culture methods that more closely mimic natural ecological habitat growth to improve our understanding of vAh pathogenesis.
Topics: Aeromonas hydrophila; Alabama; Animals; Aquaculture; Bacterial Proteins; Bacteriological Techniques; Biofilms; Chromatography, High Pressure Liquid; Fish Diseases; Gram-Negative Bacterial Infections; Ictaluridae; Plankton; Proteomics; Tandem Mass Spectrometry; Virulence; Whole Genome Sequencing
PubMed: 33407117
DOI: 10.1186/s12866-020-02065-2 -
Viruses Mar 2021is an opportunistic pathogen that infects fish, amphibians, mammals, and humans. This study isolated a myophage, vB_AhyM_Ahp2 (Ahp2), that lytically infects . We...
is an opportunistic pathogen that infects fish, amphibians, mammals, and humans. This study isolated a myophage, vB_AhyM_Ahp2 (Ahp2), that lytically infects . We observed that 96% of the Ahp2 particles adsorbed to within 18 min. Ahp2 also showed a latent period of 15 min with a burst size of 142 PFU/cell. This phage has a linear double-stranded DNA genome of 47,331 bp with a GC content of 57%. At least 20 Ahp2 proteins were detected by SDS-polyacrylamide gel electrophoresis; among them, a 40-kDa protein was predicted as the major capsid protein. Sequence analysis showed that Ahp2 has a genome organization closely related to a group of phages (13AhydR10RR, 14AhydR10RR, 85AhydR10RR, phage 3, 32 Asp37, 59.1), which infect and . The tail module encompassing ORF27-29 in the Ahp2 genome was present in all phages analyzed in this study and likely determines the host range of the virus. This study found that Ahp2 completely lyses AH300206 in 3.5 h at a MOI of 0.0001 and does not lysogenize its host. Altogether, these findings show that Ahp2 is a lytic phage and could be a candidate for therapeutic phage cocktails.
Topics: Aeromonas hydrophila; Bacteriophages; DNA Viruses; Genome, Viral; Host Specificity
PubMed: 33799428
DOI: 10.3390/v13030477 -
Ecotoxicology and Environmental Safety Sep 2023Aeromonas hydrophila is a conditional pathogen impacting public hygiene and safety. Hemolysin is a virulence factor of Aeromonas hydrophila that causes erythrocyte...
Aeromonas hydrophila is a conditional pathogen impacting public hygiene and safety. Hemolysin is a virulence factor of Aeromonas hydrophila that causes erythrocyte hemolysis, yet its transcriptional response to Cyprinus rubrofuscus remains unknown. Our investigation confirmed the hemolysis of hemolysin from A. hydrophila. Serum enzyme activity was evaluated weekly after C. rubrofuscus were immunized with hemolysin Ahh1. The results showed that the hemolysin enhances the serum superoxide dismutase (SOD), lysozyme (LZM), and catalase (CAT) activity, which reached a maximum on day 14. To elucidate the molecular interaction between hemolysin from A. hydrophila and the host, we performed transcriptome sequencing on the spleen of C. rubrofuscus 14 days post hemolysin infection. The total number of clean reads was 41.37 Gb, resulting in 79,832 unigenes with an N50 length of 1863 bp. There were 1982 significantly differentially expressed genes (DEGs), including 1083 upregulated genes and 899 downregulated genes. Transcript levels of the genes, such as LA6BL, CD2, and NLRC5, were significantly downregulated, while those of IL11, IL1R2, and IL8 were dramatically upregulated. The DEGs were mainly enriched in the immune disease, viral protein interaction with cytokine and cytokine receptor, and toll-like receptor pathways, suggesting that hemolysin stimulation can activate the transcriptional responses. RT-qPCR experiments results of seven genes, IL-8, STAT2, CTSK, PRF1, CXCL9, TLR5, and SACS, showed that their expression was highly concordant with RNA-seq data. We clarified for the first time the key genes and signaling pathways response to hemolysin from A. hydrophila, which offers strategies for treating and preventing diseases.
Topics: Animals; Spleen; Aeromonas hydrophila; Hemolysin Proteins; Hemolysis; Carps
PubMed: 37591129
DOI: 10.1016/j.ecoenv.2023.115375