Aims: This study evaluated the accuracy of three methods used in the identification of Aeromonas hydrophila, a Gramnegative bacterium found in warm aquatic environments. A. hydrophila samples from Indonesia were tested using (a) SNI 7303, developed by the Indonesian government, (b) the method of Dorsch and (c) the method of Cascón. The results obtained were compared to that of the gold standard method, which used 16S rDNA sequences. Methodology and results: Based on the Indonesian government standard identification method SNI7303, we identified 56 out of 95 samples as A. hydrophila. The samples were then screened using the PCR amplification approach developed by Dorsch and Cascón. Of the 56 samples, only 20 samples were found to be positive by either the Dorsch or Cascón methods. DNA from these 20 samples was amplified using common 16S rDNA primers and the sequences compared with available 16S rDNA sequences from the GenBank. Phylogenetic analyses on the data were performed using Clustal X and MEGA 5 software. Conclusion, significance and impact of study: Of the 56 samples positively identified as A. hydrophila using the BSN method, identity in only five samples were positively confirmed using the16S rDNA method, giving an accuracy of only 8.9%. In this connection, the Dorsch method was 31.3% accurate while the Cascón method provided 45.5% correct identification. When all three methods were used in combination, 71.4% of the samples were correctly identified. The results of the study show that methods used to identify A. hydrophila cannot be used with confidence to identify A. hydrophila from Indonesia and probably from other tropical regions as well. The genetic diversity of Aeromonas bacteria in Indonesia appears to be considerably higher than that encountered by Dorsch or Cascón. Therefore, there is a need to develop a new simple method to identify A. hydrophila from tropical regions.
Aeromonas hydrophila

Aims: Several harmful dinoflagellate species are widely found in Malaysian marine waters. These microalgae are capable of producing a variety of toxins that can intoxicate humans through consumption of contaminated seafood. Therefore, the present work aimed to investigate the potential of a marine bacterium sdPS-7 isolate as a biological control agent against Alexandrium minutum KB-5. Methodology and results: The isolate sdPS-7 was obtained from marine sediments in Malaysia and examined for its algicidal activity toward the toxic dinoflagellate A. minutum KB-5 in laboratory culture. Based on morphological and molecular characterization, this isolate was identified as Aeromonas hydrophila sdPS-7. Alexandrium minutum KB-5 cultures were exposed to cell free bacteria culture filtrate and the effect on dinoflagelate growth was evaluated based on direct cell counts in the treated samples compared to non-treated control cultures. The bacterial filtrate was treated at different temperatures, salinities and exposed to repeated freezing and thawing five times to study its algicidal activity stability thereafter. The results showed a potent inhibition of the growth of A. minutum KB-5. The strongest effect was observed when the bacterium culture filtrate was mixed with A. minutum KB-5 cultures that were in lag phase, resulting in 99% or higher mortality. The cell-free filtrate proved to be heat- stable when exposed to temperatures of 2 °C to 100 °C for one hour each. There was also no substantial salinity as well as (freezing – thawing) effect on the filtrate algicidal activity. Conclusion, significance and impact of study: This study illustrated the potential use of the marine bacterial Aeromonas hydrophila sdPS-7 filtrates in controlling the growth of the toxic dinoflagellate A. minutum KB-5.
Biological Control Agents ; Aeromonas hydrophila

No abstract available.
Aeromonas hydrophila* ; Aeromonas* ; Animals ; Histamine Release* ; Histamine* ; Mast Cells* ; Rats*

In the present study, Aeromonas (A.) hydrophila was isolated from a captive-bred adult freshwater stingray (Potamotrygon motoro) reared at a commercial aquarium in Korea. The stingray had bites on its fins, hemorrhages on the ventral part, and congested internal organs. A bacterium was isolated from kidney and subsequently identified as A. hydrophila. Based on phylogenetic analysis results, the isolate in the present study (SNUAh-LA1) was most closely related to A. hydrophila AH10 (China) and A. hydrophila AKR1 (Korea). It is most likely that the pathogen infection resulted from Potamotrygon motoro cohabiting with ricefish (Oryzias latipes).
Adult ; Aeromonas hydrophila* ; Aeromonas* ; Estrogens, Conjugated (USP) ; Fresh Water* ; Hemorrhage ; Humans ; Kidney ; Korea

Peritoneal dialysis (PD)-related peritonitis is a major cause of injury and technique failure in patients undergoing PD. Aeromonas hydrophila is ubiquitous in the environment, and is a Gram-negative rod associated with infections in fish and amphibians in most cases; however, it can also cause opportunistic infections in immunocompromised patients. We report a case of A. hydrophila peritonitis in a 56-year-old male on automated PD. Peritonitis may have been caused by contamination of the Set Plus, a component of the automated peritoneal dialysis device. Although Set Plus is disposable, the patient reused the product by cleansing with tap water. He was successfully treated with intraperitoneally-administered ceftazidime and has been well without recurrence for more than 2 years.
Aeromonas hydrophila ; Aeromonas ; Amphibians ; Ceftazidime ; Humans ; Immunocompromised Host ; Male ; Middle Aged ; Opportunistic Infections ; Peritoneal Dialysis ; Peritonitis ; Recurrence ; Water

Aeromonas hydrophila is a facultative, anaerobic gram-negative bacillus. It's a member of the family Vibrionaceae. Aeromonas, which is known to cause gastroenteritis and wound infections ranging from mild cellulitis to fulminant myonecrosis. It is responsible for opportunistic infections in patients with compromised immune function due to an underlying disease such as malignant hematological disorders, liver cirrhosis, and malignant neoplasm. We report a case of 72-year-old woman who recovered from necrotizing fasciitis caused by A. hydrophila. The patient had undergone prolonged hemodialysis and had no history of trauma.
Aeromonas hydrophila* ; Aeromonas* ; Aged ; Bacillus ; Cellulitis ; Fasciitis, Necrotizing* ; Female ; Gastroenteritis ; Humans ; Liver Cirrhosis ; Opportunistic Infections ; Renal Dialysis* ; Vibrionaceae ; Wound Infection

Aeromonas hydrophila is a facultative, anaerobic gram-negative bacillus. It's a member of the family Vibrionaceae. Aeromonas, which is known to cause gastroenteritis and wound infections ranging from mild cellulitis to fulminant myonecrosis. It is responsible for opportunistic infections in patients with compromised immune function due to an underlying disease such as malignant hematological disorders, liver cirrhosis, and malignant neoplasm. We report a case of 72-year-old woman who recovered from necrotizing fasciitis caused by A. hydrophila. The patient had undergone prolonged hemodialysis and had no history of trauma.
Aeromonas hydrophila* ; Aeromonas* ; Aged ; Bacillus ; Cellulitis ; Fasciitis, Necrotizing* ; Female ; Gastroenteritis ; Humans ; Liver Cirrhosis ; Opportunistic Infections ; Renal Dialysis* ; Vibrionaceae ; Wound Infection

4-Hydroxybutyric acid (4HB) is a psychotropic drug used for polymer synthesis such as poly (4-hydroxybutyric acid) (P4HB) and poly (3-hydroxybutyric acid-co-4-hydroxybutyric acid) (P3HB-co-4HB). 1,4-butanediol (BD) can be converted to 4-hydroxybutyric acid by alcohol dehydrogenase (DhaT) and aldehyde dehydrogenase (AldD). In this study, high efficiency promoters including T7 promoter and P(Re) promoter were cloned to increase expression of dhaT and aldD, and thus accelerate the conversion from BD to 4HB. A. hydrophila 4AK4 (pZQ01), the recombinant strain under the control of T7 promoter, produced 6.00 g/L 4HB from 10 g/L BD with the productivity increased by 43.20%. While A. hydrophila 4AK4 (pZQ04), the strain under the control of T7 promoter, produced 4.87 g/L 4HB from 10 g/L BD, and the productivity was increased by 16.23%. Thus, the gene expression was increased by T7 and P(Re) promoters, leading to an accelerated biosynthesis of 4HB.
Aeromonas hydrophila ; genetics ; metabolism ; Genetic Engineering ; Hydroxybutyrates ; metabolism ; Promoter Regions, Genetic ; genetics ; Recombination, Genetic

Polyhydroxyalkanoates (PHA) is a family of microbially synthesized polyesters consisting of various 3-hydroxyalkanoate monomers. Aeromonas hydrophila 4AK4 could be able to synthesize PHA copolymer consisting of 3-hydroxybutyrate (3-HB) and 3-hydroxyhexanoate (3-HHx). No data has been reported about the ability to synthesize the PHA with other monomers in A. hydrophila. In this study, propionic acid, valeric acid, heptanoic acid, nonanoic acid and undecanoic acid were used together with gluconate to find out whether A. hydrophila 4AK4 could synthesize the PHA consisting of odd carbon atom number monomers. The result showed that A. hydrophila 4AK4 could not growth when supplied with propionic acid, valeric acid, heptanoic acid and nonanoic acid and only undecanoic acid could be used to synthesize PHA. Wild type and recombinant A. hydrophila 4AK4 harboring phaA (beta-ketothiolase) and phaB (acetoacetyl-CoA reductase) were cultivated with undecanoic acid and glucose or undecanoic acid and gluconate served as carbon sources. PHA consisting of 3-HB and 3-hydroxyvalerate (3-HV) could be produced by both wild type and recombinant A. hydrophila 4AK4 and the latter could produce PHA with more 3-HB monomer. When the ratio of glucose or gluconate to undecanoic acid was 1:1, the cell dry weight (CDW) of A. hydrophila 4AK4 reached 1.14 g/L and PHA content was 60% of the CDW after cultivation for 24 h. When lauric acid and undecanoic acid were served as co-substrate, A. hydrophila 4AK4 could produce copolyester consisting of 3-HB, 3-HV and 3-HHx. Along with the increase of undecanoic acid proportion in the mixed carbon source, the 3-HV content of copolymer was increased while the 3-HB and 3-HHx content were decreased. In all cases, the CDW decreased along with the increase of undecanoic acid concentration, which indicated that undecanoic acid was not very good for A. hydrophila 4AK4 growth.
Aeromonas hydrophila ; metabolism ; Fatty Acids ; metabolism ; Glucose ; metabolism ; Lauric Acids ; metabolism ; Pentanoic Acids ; metabolism ; Polyhydroxyalkanoates ; biosynthesis

OBJECTIVETo investigate the infection status and virulent genes of Aeromonas in patients with acute diarrhea in Pudong New Area, Shanghai.

METHODSIn 2012, stool samples were collected from diarrhea patients in 12 sentinel hospitals in Pudong for the detections of 13 pathogens causing diarrhea, and the detections of 5 diarrhea related virulent genes were conducted for Aeromonas isolates.

RESULTSA total of 101 patients were infected with Aeromonas in 2533 patients (4.0%). A total of 101 Aeromonas strains were isolated, including 17 Aeromonas hydrophila strains (18.8%), 44 Aeromonas veronii biovar sobria strains (52.5%) and 12 Aeromonas caviae strains (29.7%). And 44 coinfections with other pathogens were detected. Aeromonas infection mainly occurred in summer and in people aged ≥20 years. Among the patients infected with Aeromonas, 71 (70.3%) had watery diarrhea, 20 (19.8%) had vomiting and 11 (10.9%) had fever. Virulent genes detection showed that 95.0% of the Aeromonas. strains carried virulent genes, and the detection rates of hlyA, aerA, act, alt, and ast genes were 5.9%, 6.9%, 67.3%, 42.6% and 13.9%, respectively.

CONCLUSIONSHigh incidence of Aeromonas infection was found in the patients with acute diarrhea in Pudong, and a high proportion of coinfections with other pathogens was detected too. Most Aeromonas strains carried virulent genes, and the distribution varied.

Aeromonas ; genetics ; Aeromonas hydrophila ; genetics ; China ; epidemiology ; Diarrhea ; microbiology ; Gram-Negative Bacterial Infections ; epidemiology ; microbiology ; Humans ; Seasons ; Virulence ; genetics ; Young Adult