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Sample records for psychrophilum aeromonas salmonicida

  1. Resistance of Salmonds Against Aeromonas Salmonicida

    DEFF Research Database (Denmark)

    Holten-Andersen, Lars; Dalsgaard, Inger; Buchmann, Kurt

    2011-01-01

    Furunculosis, caused by Aeromonas salmonicida, continues to be a health problem for the growing salmonid aquaculture. Despite effective vaccination programs regular outbreaks occur at Danish trout farms calling for repeated antibiotic treatment. We hypothesized that a difference in natural...... susceptibility to this disease might exist between Baltic salmon and the widely used rainbow trout. Hence, a cohabitation challenge model was applied to investigate the relative susceptibility to infection with Aeromonas salmonicida in rainbow trout and Baltic salmon. The course of infection was monitored daily...... over a 30-day period post challenge and the results were summarized in mortality curves. A. salmonicida was recovered from mortalities during the entire test period. At day 30 the survival was 6.2 % and 34.0 % for rainbow trout and Baltic salmon, respectively. Significant differences in susceptibility...

  2. AEROMONAS SALMONICIDA INFECTION IN VACCINATED RAINBOW TROUT

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Skov, Jakob; Mohammad, Rezkar Jaafar

    In vivo testing of any candidate vaccine is influenced by the choice of challenge method and the external environmental conditions. In the present study, a comparative challenge study was performed to evaluate the efficacy of different vaccines against the bacterial pathogen Aeromonas salmonicida...... in saltwater condition produced less mortality compared to freshwater, probably due to the growth inhibition of A. salmonicida in saline condition which was also verified by in vitro assay. One of the experimental vaccines emulsified in water in oil adjuvant showed a protection comparable...... effects due to oil adjuvants, and the importance of choice of challenge methods used will be discussed....

  3. Biological control of Aeromonas salmonicida subsp. salmonicida infection in rainbow trout (Oncorhynchus mykiss) using Aeromonas phage PAS-1.

    Science.gov (United States)

    Kim, J H; Choresca, C H; Shin, S P; Han, J E; Jun, J W; Park, S C

    2015-02-01

    The potential control efficacy of Aeromonas phage PAS-1 was evaluated against Aeromonas salmonicida subsp. salmonicida infection in rainbow trout (Oncorhynchus mykiss) model in this study. The phage was co-cultured with the virulent A. salmonicida subsp. salmonicida strain AS05 that possesses the type III secretion system (TTSS) ascV gene, and efficient bacteriolytic activity was observed against the bacteria. The administration of PAS-1 in rainbow trout demonstrated that the phage was cleared from the fish within 200 h post-administration, and a temporal neutralizing activity against the phage was detected in the sera of phage-administrated fish. The administration of PAS-1 (multiplicity of infection: 10 000) in A. salmonicida subsp. salmonicida infected rainbow trout model showed notable protective effects, with increased survival rates and mean times to death. These results demonstrated that Aeromonas phage PAS-1 could be considered as an alternative biological control agent against A. salmonicida subsp. salmonicida infections in rainbow trout culture.

  4. Optimization of a plasmid electroporation protocol for Aeromonas salmonicida subsp. salmonicida.

    Science.gov (United States)

    Dallaire-Dufresne, Stéphanie; Emond-Rheault, Jean-Guillaume; Attéré, Sabrina A; Tanaka, Katherine H; Trudel, Mélanie V; Frenette, Michel; Charette, Steve J

    2014-03-01

    Aeromonas salmonicida subsp. salmonicida is a major fish pathogen. Molecular tools are required to study the virulence and genomic stability of this bacterium. An efficient electroporation-mediated transformation protocol for A. salmonicida subsp. salmonicida would make genetic studies faster and easier. In the present study, we designed the 4.1-kb pSDD1 plasmid as a tool for optimizing an electroporation protocol for A. salmonicida subsp. salmonicida. We systematically tested the electroporation conditions to develop a protocol that generates the maximum number of transformants. Under these optimal conditions (25 kV/cm, 200 Ω, 25 μF), we achieved an electroporation efficiency of up to 1×10(5) CFU/μg DNA. The electroporation protocol was also tested using another plasmid of 10.6-kb and three different strains of A. salmonicida subsp. salmonicida. The strains displayed significant differences in their electro-transformation competencies. Strain 01-B526 was the easiest to electroporate, especially with the pSDD1 plasmid. This plasmid was stably maintained in the 01-B526 transformants, as were the native plasmids, but could be easily cured by removing the selection conditions. This is the first efficient electroporation protocol reported for A. salmonicida subsp. salmonicida, and offers new possibilities for studying this bacterium.

  5. Characterization of atypical Aeromonas salmonicida by different methods

    DEFF Research Database (Denmark)

    Austin, B.; Austin, D.A.; Dalsgaard, Inger;

    1998-01-01

    Fifty two isolates of atypical Aeromonas salmonicida, recovered from a wide range of hosts and geographical locations, were heterogeneous in terms of molecular and phenotypic characteristics, and represented taxa which could not be accommodated by the current classification of four subspecies...

  6. Potential role of specific antibodies in vaccine-induced protection against Aeromonas salmonicida subsp. salmonicida in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Villumsen, Kasper Rømer; Dalsgaard, Inger; Raida, Martin Kristian

    2012-01-01

    Furunculosis caused by infection with Aeromonas salmonicida subsp. salmonicida has now been a known threat to aquaculture for more than a century. Efficient prophylactic precautions against this disease are essential for continued growth of salmonid fish aquaculture. Ever since the introduction...

  7. Characterization of atypical Aeromonas salmonicida isolates by ribotyping and plasmid profiling

    DEFF Research Database (Denmark)

    Pedersen, Karl; Dalsgaard, Inger; Larsen, J.L.

    1996-01-01

    A total of 38 strains of atypical Aeromonas salmonicida, three oxidase-negative but otherwise typical Aer. salmonicida, three typical Aer. salmonicida, and two reference strains, isolated from several countries and fish species were examined with respect to rRNA gene restriction patterns (ribotypes...

  8. Infection of sea lamprey with an unusual strain of Aeromonas salmonicida

    Science.gov (United States)

    Diamanka, Arfang; Loch, Thomas P.; Cipriano, Rocco C.; Winters, Andrew D.; Faisal, Mohamed

    2014-01-01

    The invasion of the Laurentian Great Lakes by the fish-parasitic sea lamprey has led to catastrophic consequences, including the potential introduction of fish pathogens. Aeromonas salmonicida is a bacterial fish pathogen that causes devastating losses worldwide. Currently, there are five accepted subspecies of Aeromonas salmonicida: A. salmonicida subsp. salmonicida, masoucida, smithia, achromogenes, and pectinolytica. We discuss the discovery of an isolate of A. salmonicida that is pathogenic to rainbow trout (Oncorhynchus mykiss) and exhibits unique phenotypic and molecular characteristics. We examined 181 adult sea lamprey (Petromyzon marinus) from the Humber River (Lake Ontario watershed) and 162 adult sea lamprey from Duffins Creek (Lake Ontario watershed) during the spring seasons of 2005–11. Among those, 4/343 (1.2%) sea lamprey were culture positive for A. salmonicida, whereby biochemical and molecular studies identified three of the isolates as A. salmonicida subsp. salmonicida. The remaining isolate (As-SL1) recovered from Humber River sea lamprey was phenotypically more similar to A. salmonicida subsp. salmonicida than to the four other A. salmonicida subspecies. However, unlike A. salmonicida subsp. salmonicida, As-SL1 was sucrose positive, produced an acid-over-acid reaction on triple-sugar iron medium and did not amplify with A. salmonicida subsp. salmonicida specific primers. Phylogenetic analysis based on partial stretches of the 16S rRNA and DNA gyrase subunit B genes further confirmed that the As-SL1 isolate was not A. salmonicida subsp. masoucida, smithia, achromogenes, or pectinolytica. Based on our analyses, the As-SL1 isolate is either an unusual strain of A. salmonicida subsp. salmonicida or a novel A. salmonicida subspecies. The four A. salmonicida isolates that were recovered from sea lamprey were pathogenic to rainbow trout in experimental challenge studies. Our study also underscores the potential role of sea lamprey in the ecology of

  9. The genome of Aeromonas salmonicida subsp. salmonicida A449: insights into the evolution of a fish pathogen

    Directory of Open Access Journals (Sweden)

    Murphy Colleen

    2008-09-01

    Full Text Available Abstract Background Aeromonas salmonicida subsp. salmonicida is a Gram-negative bacterium that is the causative agent of furunculosis, a bacterial septicaemia of salmonid fish. While other species of Aeromonas are opportunistic pathogens or are found in commensal or symbiotic relationships with animal hosts, A. salmonicida subsp. salmonicida causes disease in healthy fish. The genome sequence of A. salmonicida was determined to provide a better understanding of the virulence factors used by this pathogen to infect fish. Results The nucleotide sequences of the A. salmonicida subsp. salmonicida A449 chromosome and two large plasmids are characterized. The chromosome is 4,702,402 bp and encodes 4388 genes, while the two large plasmids are 166,749 and 155,098 bp with 178 and 164 genes, respectively. Notable features are a large inversion in the chromosome and, in one of the large plasmids, the presence of a Tn21 composite transposon containing mercury resistance genes and an In2 integron encoding genes for resistance to streptomycin/spectinomycin, quaternary ammonia compounds, sulphonamides and chloramphenicol. A large number of genes encoding potential virulence factors were identified; however, many appear to be pseudogenes since they contain insertion sequences, frameshifts or in-frame stop codons. A total of 170 pseudogenes and 88 insertion sequences (of ten different types are found in the A. salmonicida genome. Comparison with the A. hydrophila ATCC 7966T genome reveals multiple large inversions in the chromosome as well as an approximately 9% difference in gene content indicating instances of single gene or operon loss or gain. A limited number of the pseudogenes found in A. salmonicida A449 were investigated in other Aeromonas strains and species. While nearly all the pseudogenes tested are present in A. salmonicida subsp. salmonicida strains, only about 25% were found in other A. salmonicida subspecies and none were detected in other

  10. Aeromonas salmonicida bacteremia associated with chronic well water consumption in a patient with diabetes

    Directory of Open Access Journals (Sweden)

    Christine Ann Moore

    2017-01-01

    Full Text Available Aeromonas salmonicida is associated with superficial skin infections in fish. Its virulence factors allow colonization of water including surface water such as salt water, beaches, and fresh water wells. Moreover, it is possible for immunocompromised patients to develop invasive disease after chronic exposure to Aeromonas spp. through contaminated water. While there are reports of Aeromonas spp. bacteremia following water ingestion, there have been no reports of A. salmonicida bacteremia from water consumption. We report the first case of A. salmonicida bacteremia in a patient with diabetes due to chronic consumption of well water.

  11. Aeromonas salmonicida subsp. salmonicida strains isolated from Chinese freshwater fish contain a novel genomic island and possible regional-specific mobile genetic elements profiles

    DEFF Research Database (Denmark)

    Long, Meng; Nielsen, Tue Kjærgaard; Leisner, Jørgen Johannes

    2016-01-01

    Two strains of Aeromonas salmonicida, YK and BG, were isolated from largemouth bronze gudgeon and northern whitefish in China, and identified as A. salmonicida subsp. salmonicida based on phylogenetic analysis of vapA and 16S rRNA gene sequences. YK and BG originated from freshwater fish, one of ...

  12. Recovery of atypical Aeromonas salmonicida from ulcerated fish from the Baltic Sea

    DEFF Research Database (Denmark)

    Wiklund, T.; Tabolina, I; Bezgachina, T.V.

    1999-01-01

    Ulcerated fish of six different species were collected during the BMB/ICES Sea-going Workshop "Fish Diseases and Parasites in the Baltic Sea", 25 November to 8 December 1994, and examined for bacteriological infections. Atypical Aeromonas salmonicida strains were isolated from the majority of the......, well-defined biotype of A. salmonicida. (C) 1999 International Council for the Exploration of the Sea....

  13. Effects of temperature on biochemical reactions and drug resistance of virulent and avirulent Aeromonas salmonicida

    Science.gov (United States)

    Hahnel, G.B.; Gould, R.W.

    1982-01-01

    Incubation temperatures of 11°, 18° and 28° did not substantially affect biochemical reactions of either virulent or avirulent forms of Aeromonas salmonicida subspecies salmonicida. The only change observed, amygdalin fermentation, was positive at 11° and 18° but negative at 28°C. Several isolates utilized sucrose, a characteristic not normally recognized for A. salmonicida subspecies salmonicida.Antimicrobial susceptibility screening indicated resistance to novobiocin increased at the higher incubation temperatures. Standardized drug sensitivity testing procedures and precise zone diameter interpretive standards for bacterial fish pathogens are needed.

  14. Aeromonas salmonicida - Epidemiology, whole genome sequencing, detection and in vivo imaging

    DEFF Research Database (Denmark)

    Bartkova, Simona

    Aeromonas salmonicida subsp. salmonicida is a bacterial fish pathogen that is the causative agent of furunculosis, a septicemic infection responsible for great losses in aquaculture around the world. In Denmark furunculosis was first seen in freshwater in the 1950s, though currently the infection...... resistance against antibiotics. This study provided valuable information regarding the Danish disease causing A. salmonicida....... effects. Antibiotics are therefore used as treatment, which due to the possibility of developing resistance is neither a favorable nor sustainable solution. To complicate things further, it is possible that fish can be carriers of A. salmonicida and transfer the bacterium from freshwater to the sea where......-time PCR and bacterial culturing were employed for preliminary screening of A. salmonicida in 40 fish from Danish fresh- and seawater farms. A. salmonicida was detected by realtime PCR in freshwater farm fish showing no sign of disease, indicating possible presence of carrier fish. Out of five examined...

  15. Infection routes of Aeromonas salmonicida in rainbow trout monitored in vivo by real-time bioluminescence imaging

    DEFF Research Database (Denmark)

    Bartkova, Simona; Kokotovic, Branko; Dalsgaard, Inger

    2017-01-01

    , we employ bacterial BLI for examining routes of entry and spread of Aeromonas salmonicida susbp. salmonicida in rainbow trout. A virulent Danish A. salmonicida strain was tagged with pAKgfplux1, a dual-labelled plasmid vector containing the mutated gfpmut3a gene from Aequorea victoria and the lux...

  16. Triclosan Resistance in a Bacterial Fish Pathogen, Aeromonas salmonicida subsp. salmonicida, is Mediated by an Enoyl Reductase, FabV.

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    Khan, Raees; Lee, Myung Hwan; Joo, Hae-Jin; Jung, Yong-Hoon; Ahmad, Shabir; Choi, Jin-Hee; Lee, Seon-Woo

    2015-04-01

    Triclosan, the widely used biocide, specifically targets enoyl-acyl carrier protein reductase (ENR) in the bacterial fatty acid synthesis system. Although the fish pathogen Aeromonas salmonicida subsp. salmonicida exhibits triclosan resistance, the nature of this resistance has not been elucidated. Here, we aimed to characterize the triclosan resistance of A. salmonicida subsp. salmonicida causing furunculosis. The fosmid library of triclosan-resistant A. salmonicida subsp. salmonicida was constructed to select a fosmid clone showing triclosan resistance. With the fosmid clone showing triclosan resistance, a subsequent secondary library search resulted in the selection of subclone pTSR-1. DNA sequence analysis of pTSR-1 revealed the presence of a chromosomal-borne fabV-encoding ENR homolog. The ENR of A. salmonicida (FabVas) exhibited significant homology with previously known FabV, including the catalytic domain YX(8)K. fabVas introduction into E. coli dramatically increased its resistance to triclosan. Heterologous expression of FabVas might functionally replace the triclosan-sensitive FabI in vivo to confer E. coli with triclosan resistance. A genome-wide search for fabVas homologs revealed the presence of an additional fabV gene (fabVas2) paralog in A. salmonicida strains and the fabVas orthologs from other gram-negative fish pathogens. Both of the potential FabV ENRs expressed similarly with or without triclosan supplement. This is the first report about the presence of two potential FabV ENRs in a single pathogenic bacterium. Our result suggests that triclosan-resistant ENRs are widely distributed in various bacteria in nature, and the wide use of this biocide can spread these triclosan-tolerant ENRs among fish pathogens and other pathogenic bacteria.

  17. First isolation of Aeromonas salmonicida subspecies salmonicida from diseased sea bass, Dicentrarchus labrax (L., cultured in Spain

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    Clara Fernández-Álvarez

    2016-11-01

    Full Text Available This work represents the first description of Aeromonas salmonicida subsp. salmonicida as causative agent of furunculosis in cultured sea bass, Dicentrarchus labrax (L.. Cumulative mortality in affected fish from two floating cages in the Mediterranean coast of Spain was 3.8%. Affected sea bass did not show the typical external signs of furunculosis in the first stages of the disease, however, when the disease progressed, open ulcers appeared on the skin and muscle. Internally, splenomegaly was the only pathological sign observed. Samples from diseased fish were subjected to standardized assays for pathogens screening. Negative results were obtained for parasites and fish viruses. A Gram-stain-negative rod-shaped bacterium was observed in smears from liver, kidney and spleen of all analysed fish. Pure bacterial cultures were recovered from liver, kidney and spleen of all diseased fish sampled during the two different outbreaks. Bacteriological, serological, molecular and chemotaxonomic analysis allowed the identification of the causative agent of sea bass mortalities as Aeromonas salmonicida subsp. salmonicida. The bacterial strains were susceptible to most of antimicrobial agents usually employed in aquaculture except to oxytetracycline. Pathogenicity assays demonstrated that the isolated bacteria were virulent for sea bass, turbot and rainbow trout.

  18. Identification of atypical Aeromonas salmonicida : Inter-laboratory evaluation and harmonization of methods

    DEFF Research Database (Denmark)

    Dalsgaard, Inger; Gudmundsdottir, B.K.; Helgason, S.;

    1998-01-01

    The atypical isolates of Aeromonas salmonicida are becoming increasingly important as the frequency of isolation of bacteria belonging to this group continues to rise. The primary object of this study was to compare and evaluate the results obtained in various laboratories concerning the biochemi......The atypical isolates of Aeromonas salmonicida are becoming increasingly important as the frequency of isolation of bacteria belonging to this group continues to rise. The primary object of this study was to compare and evaluate the results obtained in various laboratories concerning...

  19. Diversity and homogeneity among small plasmids of Aeromonas salmonicida subsp. salmonicida linked with geographical origin

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    Sabrina A Attéré

    2015-11-01

    Full Text Available Furunculosis, which is caused by Aeromonas salmonicida subsp. salmonicida, is a major salmonid disease in fish farms worldwide. Several plasmids found in this bacterium confer phenotypes such drug resistance and virulence. Small plasmids (pAsa1, pAsa2, pAsa3, and pAsal1 related to ColE1- and ColE2-type replicons are usually present in its normal plasmidome. In the present study, with the objective to investigate if these plasmids display particularities related to the origin of the isolates bearing them, a total of 153 isolates, including 78 new and 75 previously described, were analyzed for the presence of small plasmids by PCR and DNA restriction fragment profiling. A geographical dichotomy between Canadian and European isolates for their propensity to do not have pAsa3 or pAsal1 was found. In addition, the genotyping analysis led to the identification of two European isolates harboring an unusual pAsal1. An investigation by next-generation sequencing (NGS of these two isolates shed light on two pAsal1 variants (pAsal1C and pAsal1D. As with pAsal1B, another pAsal1 variant previously described, these two new variants bore a second insertion sequence (ISAS5 in addition to the usual ISAS11. The characterization of these variants suggested that they could predominate over the wild-type pAsal1 in stressful conditions such as growth at temperatures of 25°C and above. To obtain a comprehensive portrait of the mutational pressure on small plasmids, 26 isolates whose DNA had been sequenced by NGS were investigated. pAsa3 and pAsal1 were more prone to mutations than pAsa1 and pAsa2, especially in the mobA gene, which encodes a relaxase and a primase. Lastly, the average copy number of each plasmid per cell was assessed using raw sequencing data. A clear trend with respect to the relative proportion per cell of each plasmid was identified. Our large-scale study revealed a geographical dichotomy in small plasmid repertoire in addition to a clear trend

  20. The mosaic architecture of Aeromonas salmonicida subsp. salmonicida pAsa4 plasmid and its consequences on antibiotic resistance

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    Katherine H. Tanaka

    2016-10-01

    Full Text Available Aeromonas salmonicida subsp. salmonicida, the causative agent of furunculosis in salmonids, is an issue especially because many isolates of this bacterium display antibiotic resistances, which limit treatments against the disease. Recent results suggested the possible existence of alternative forms of pAsa4, a large plasmid found in A. salmonicida subsp. salmonicida and bearing multiple antibiotic resistance genes. The present study reveals the existence of two newly detected pAsa4 variants, pAsa4b and pAsa4c. We present the extensive characterization of the genomic architecture, the mobile genetic elements and the antimicrobial resistance genes of these plasmids in addition to the reference pAsa4 from the strain A449. The analysis showed differences between the three architectures with consequences on the content of resistance genes. The genomic plasticity of the three pAsa4 variants could be partially explained by the action of mobile genetic elements like insertion sequences. Eight additional isolates from Canada and Europe that bore similar antibiotic resistance patterns as pAsa4-bearing strains were genotyped and specific pAsa4 variants could be attributed to phenotypic profiles. pAsa4 and pAsa4c were found in Europe, while pAsa4b was found in Canada. In accordance with their content in conjugative transfer genes, only pAsa4b and pAsa4c can be transferred by conjugation in Escherichia coli. The plasticity of pAsa4 variants related to the acquisition of antibiotic resistance indicates that these plasmids may pose a threat in terms of the dissemination of antimicrobial-resistant A. salmonicida subsp. salmonicida bacteria.

  1. The mosaic architecture of Aeromonas salmonicida subsp. salmonicida pAsa4 plasmid and its consequences on antibiotic resistance

    Science.gov (United States)

    Tanaka, Katherine H.; Vincent, Antony T.; Trudel, Mélanie V.; Paquet, Valérie E.; Frenette, Michel

    2016-01-01

    Aeromonas salmonicida subsp. salmonicida, the causative agent of furunculosis in salmonids, is an issue especially because many isolates of this bacterium display antibiotic resistances, which limit treatments against the disease. Recent results suggested the possible existence of alternative forms of pAsa4, a large plasmid found in A. salmonicida subsp. salmonicida and bearing multiple antibiotic resistance genes. The present study reveals the existence of two newly detected pAsa4 variants, pAsa4b and pAsa4c. We present the extensive characterization of the genomic architecture, the mobile genetic elements and the antimicrobial resistance genes of these plasmids in addition to the reference pAsa4 from the strain A449. The analysis showed differences between the three architectures with consequences on the content of resistance genes. The genomic plasticity of the three pAsa4 variants could be partially explained by the action of mobile genetic elements like insertion sequences. Eight additional isolates from Canada and Europe that bore similar antibiotic resistance patterns as pAsa4-bearing strains were genotyped and specific pAsa4 variants could be attributed to phenotypic profiles. pAsa4 and pAsa4c were found in Europe, while pAsa4b was found in Canada. In accordance with their content in conjugative transfer genes, only pAsa4b and pAsa4c can be transferred by conjugation in Escherichia coli. The plasticity of pAsa4 variants related to the acquisition of antibiotic resistance indicates that these plasmids may pose a threat in terms of the dissemination of antimicrobial-resistant A. salmonicida subsp. salmonicida bacteria. PMID:27812409

  2. Isolation and Characterization of a New Subspecies of Aeromonas salmonicida (Aeromonas salmonicida subsp.Flounderacida subsp.Nov.) from Stone Flounder(Kareius bicoloratus L.)

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaojun(张晓君); Zhan Wenbin; Chen Cuizhen; Fang Hai

    2004-01-01

    Biological properties were studied to appropriate pathogenic bacteria which were isolated from di-seased (or dead) stone flounder (Kareius bicoloratus L.) which expressed bacterial septicaemia, including morphological characteristics, colony characteristics, physiological and biochemical characteristics and serum homology of isolates, the results showed that the isolates belonged to a new subspecies of A.salmonicida. In addition, the representative strains have been re-checked and detected the mol% G+C ratio of the DNA by China Center for Type Culture Collection (CCTCC), the examined strains were also regarded as a new subspecies of A.salmonicida, and designated as Aeromonas salmonicida subsp. flounderacida subsp.nov.by its isolated fish (Kareius bicoloratus). Molecular identification of analysis of the nucleotide sequence of the 16S rRNA gene were applied, the results showed high similarity (99%) with the 16S rRNA gene of Aeromonas salmonicida from GenBank database. Cluster analysis of phylogenetic tree revealed that the representative strain formed separately bootstrap-supported cluster.

  3. The Aeromonas salmonicida Lipopolysaccharide Core from Different Subspecies: The Unusual subsp. pectinolytica.

    Science.gov (United States)

    Merino, Susana; Tomás, Juan M

    2016-01-01

    Initial hydridization tests using Aeromonas salmonicida typical and atypical strains showed the possibility of different lipopolysaccharide (LPS) outer cores among these strains. By chemical structural analysis, LPS-core SDS-PAGE gel migration, and functional and comparative genomics we demonstrated that typical A. salmonicida (subsp. salmonicida) strains and atypical subsp. masoucida and probably smithia strains showed the same LPS outer core. A. salmonicida subsp. achromogenes strains show a similar LPS outer core but lack one of the most external residues (a galactose linked α1-6 to heptose), not affecting the O-antigen LPS linkage. A. salmonicida subsp. pectinolytica strains show a rather changed LPS outer core, which is identical to the LPS outer core from the majority of the A. hydrophila strains studied by genomic analyses. The LPS inner core in all tested A. salmonicida strains, typical and atypical, is well-conserved. Furthermore, the LPS inner core seems to be conserved in all the Aeromonas (psychrophilic or mesophilic) strains studied by genomic analyses.

  4. Polyphasic characterization of Aeromonas salmonicida isolates recovered from salmonid and non-salmonid fish

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    Diamanka, A.; Loch, T.P.; Cipriano, R.C.; Faisal, M.

    2013-01-01

    Michigan's fisheries rely primarily upon the hatchery propagation of salmonid fish for release in public waters. One limitation on the success of these efforts is the presence of bacterial pathogens, including Aeromonas salmonicida, the causative agent of furunculosis. This study was undertaken to determine the prevalence of A. salmonicida in Michigan fish, as well as to determine whether biochemical or gene sequence variability exists among Michigan isolates. A total of 2202 wild, feral and hatchery-propagated fish from Michigan were examined for the presence of A. salmonicida. The examined fish included Chinook salmon, Oncorhynchus tshawytscha (Walbaum), coho salmon, O. kisutcha (Walbaum), steelhead trout, O. mykiss (Walbaum), Atlantic salmon, Salmo salar L., brook trout, Salvelinus fontinalis (Mitchill), and yellow perch, Perca flavescens (Mitchill). Among these, 234 fish yielded a brown pigment-producing bacterium that was presumptively identified as A. salmonicida. Further phenotypic and phylogenetic analyses identified representative isolates as Aeromonas salmonicida subsp. salmonicida and revealed some genetic and biochemical variability. Logistic regression analyses showed that infection prevalence varied according to fish species/strain, year and gender, whereby Chinook salmon and females had the highest infection prevalence. Moreover, this pathogen was found in six fish species from eight sites, demonstrating its widespread nature within Michigan.

  5. Occurrence and significance of atypical Aeromonas salmonicida in non-salmonid and salmonid fish species : A review

    OpenAIRE

    Wiklund, T.; Dalsgaard, Inger

    1998-01-01

    Bacterial strains of Aeromonas salmonicida included in the recognized subsp. achromogenes, subsp, masoucida, and subsp. smithia in addition to the large number of strains not included in any of the described subspecies are referred to as atypical A. salmonicida. The atypical strains form a very heterogeneous group with respect to biochemical characteristics, growth conditions, and production of extracellular proteases. Consequently, the present taxonomy of the species A. salmonicida is rather...

  6. Positive correlation between Aeromonas salmonicida vaccine antigen concentration and protection in vaccinated rainbow trout Oncorhynchus mykiss evaluated by a tail fin infection model

    DEFF Research Database (Denmark)

    Marana, M. H.; Skov, J.; Chettri, Jiwan Kumar;

    2016-01-01

    Rainbow trout, Oncorhynchus mykiss (Walbaum), are able to raise a protective immune response against Aeromonas salmonicida subsp. salmonicida (AS) following injection vaccination with commercial vaccines containing formalin-killed bacteria, but the protection is often suboptimal under Danish...... mariculture conditions. We elucidated whether protection can be improved by increasing the concentration of antigen (formalin-killed bacteria) in the vaccine. Rainbow trout juveniles were vaccinated by intraperitoneal (i.p.) injection with a bacterin of Aeromonas salmonicida subsp. salmonicida strain 090710...

  7. The improved PCR of the fstA (ferric siderophore receptor) gene differentiates the fish pathogen Aeromonas salmonicida from other Aeromonas species.

    Science.gov (United States)

    Beaz-Hidalgo, Roxana; Latif-Eugenín, Fadua; Figueras, María José

    2013-10-25

    The members of the genus Aeromonas are autochthonous of aquatic ecosystems and several species have been associated to septicaemia, ulcerative and haemorrhagic diseases in fish, causing significant mortality in both wild and farmed, freshwater and marine fish species. The species Aeromonas salmonicida is generally recognized as the most important fish pathogen responsible for epidemic outbreaks of furunculosis in salmonids, also being able to produce infections in other cultured fish such as turbot, halibut, sea bream or goldfish. New species, i.e. Aeromonas aquariorum, Aeromonas tecta and Aeromonas piscicola, have recently been discovered and isolated from diseased fish. The species A. piscicola and Aeromonas bestiarum are practically impossible to differentiate phenotypically and genetically (when using the 16S rRNA gene) from each other and from A. salmonicida. In the present study, two previously described PCR protocols, based on the fstA and gyrB genes, for the specific detection of A. salmonicida were re-evaluated with the type strains of all Aeromonas species and with a set of A. piscicola and A. bestiarum strains. Contrary to what had been published previously it was demonstrated that the gyrB-PCR is not specific for A. salmonicida because of cross-reactions with other Aeromonas species. However, in agreement with previous results, A. salmonicida was detected on the basis of the fstA-PCR, for which an improved protocol was proposed.

  8. Subunit vaccine candidates against Aeromonas salmonicida in rainbow trout Oncorhynchus mykiss

    Science.gov (United States)

    Jørgensen, Louise von Gersdorff; Skov, Jakob; Chettri, Jiwan Kumar; Holm Mattsson, Andreas; Dalsgaard, Inger; Kania, Per Walter; Buchmann, Kurt

    2017-01-01

    Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis and a major fish health problem in salmonid aquaculture worldwide. Injection vaccination with commercial mineral oil-adjuvanted bacterin vaccines has been partly successful in preventing the disease but in Danish rainbow trout (Oncorhynchus mykiss, Walbaum) aquaculture furunculosis outbreaks still occur. In this study we tested the efficacy of experimental subunit vaccines against A. salmonicida infection in rainbow trout. We utilized in silico screening of the proteome of A. salmonicida subsp. salmonicida strain A449 and identified potential protective protein antigens that were tested by in vivo challenge trial. A total of 14 proteins were recombinantly expressed in Escherichia coli and prepared in 3 different subunit vaccine combinations to immunize 3 groups of rainbow trout by intraperitoneal (i.p.) injection. The fish were exposed to virulent A. salmonicida 7 weeks after immunization. To assess the efficacy of the subunit vaccines we evaluated the immune response in fish after immunization and challenge infection by measuring the antibody levels and monitoring the survival of fish in different groups. The survival of fish at 3 weeks after challenge infection showed that all 3 groups of fish immunized with 3 different protein combinations exhibited significantly lower mortalities (17–30%) compared to the control groups (48% and 56%). The ELISA results revealed significantly elevated antibody levels in fish against several protein antigens, which in some cases were positively correlated to the survival. PMID:28182704

  9. The impact of quorum sensing on the virulence of Aeromonas hydrophila and Aeromonas salmonicida towards burbot (Lota lota L.) larvae.

    Science.gov (United States)

    Natrah, F M I; Alam, Md Iftakharul; Pawar, Sushant; Harzevili, A Shiri; Nevejan, Nancy; Boon, Nico; Sorgeloos, Patrick; Bossier, Peter; Defoirdt, Tom

    2012-09-14

    In this study, the link between quorum sensing in Aeromonas spp. and its virulence towards burbot (Lota lota) was investigated. High mortality occurred in burbot juveniles challenged with Aeromonas salmonicida HN-00, but not in juveniles challenged with Aeromonas hydrophila AH-1N. Meanwhile, both A. hydrophila AH-1N and A. salmonicida HN-00 were virulent towards larvae. The effect of quorum sensing on the virulence of A. hydrophila AH-1N towards burbot larvae was further investigated using quorum sensing mutants (N-(butyryl)-L-homoserine lactone production and receptor mutants). Challenge with these mutants resulted in higher survival of burbot larvae when compared to challenge with the wild type, and the addition of the signal molecule N-butyryl-L-homoserine lactone restored the virulence of the quorum sensing production mutant. Moreover, quorum sensing inhibitors protected the burbot larvae from both Aeromonas strains. Finally, the freshwater micro-algae Chlorella saccharophila and Chlamydomonas reinhardtii, which are able to interfere with quorum sensing, also protected burbot from the pathogens. However, QS interference was unlikely to be the only mechanism. This study revealed that the virulence of Aeromonas spp. towards burbot is regulated by quorum sensing and that quorum sensing inhibitors and micro-algae are promising biocontrol agents.

  10. Subunit vaccine candidates against Aeromonas salmonicida in rainbow trout Oncorhynchus mykiss

    DEFF Research Database (Denmark)

    Marana, Moonika Haahr; Jørgensen, Louise von Gersdorff; Skov, Jakob

    2017-01-01

    .p.) injection. The fish were exposed to virulent A. salmonicida 7 weeks after immunization. To assess the efficacy of the subunit vaccines we evaluated the immune response in fish after immunization and challenge infection by measuring the antibody levels and monitoring the survival of fish in different groups......Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis and a major fish health problem in salmonid aquaculture worldwide. Injection vaccination with commercial mineral oil-adjuvanted bacterin vaccines has been partly successful in preventing the disease but in Danish....... The survival of fish at 3 weeks after challenge infection showed that all 3 groups of fish immunized with 3 different protein combinations exhibited significantly lower mortalities (17-30%) compared to the control groups (48% and 56%). The ELISA results revealed significantly elevated antibody levels in fish...

  11. Subunit vaccine candidates against Aeromonas salmonicida in rainbow trout Oncorhynchus mykiss

    DEFF Research Database (Denmark)

    Marana, Moonika Haahr; Jørgensen, Louise von Gersdorff; Skov, Jakob

    2017-01-01

    .p.) injection. The fish were exposed to virulent A. salmonicida 7 weeks after immunization. To assess the efficacy of the subunit vaccines we evaluated the immune response in fish after immunization and challenge infection by measuring the antibody levels and monitoring the survival of fish in different groups......Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis and a major fish health problem in salmonid aquaculture worldwide. Injection vaccination with commercial mineral oil-adjuvanted bacterin vaccines has been partly successful in preventing the disease but in Danish....... The survival of fish at 3 weeks after challenge infection showed that all 3 groups of fish immunized with 3 different protein combinations exhibited significantly lower mortalities (17–30%) compared to the control groups (48% and 56%). The ELISA results revealed significantly elevated antibody levels in fish...

  12. Detection and quantification of Aeromonas salmonicida in fish tissue by real-time PCR.

    Science.gov (United States)

    Bartkova, S; Kokotovic, B; Skall, H F; Lorenzen, N; Dalsgaard, I

    2017-02-01

    Furunculosis, a septicaemic infection caused by the bacterium Aeromonas salmonicida subsp. salmonicida, currently causes problems in Danish seawater rainbow trout production. Detection has mainly been achieved by bacterial culture, but more rapid and sensitive methods are needed. A previously developed real-time PCR assay targeting the plasmid encoded aopP gene of A. salmonicida was, in parallel with culturing, used for the examination of five organs of 40 fish from Danish freshwater and seawater farms. Real-time PCR showed overall a higher frequency of positives than culturing (65% of positive fish by real-time PCR compared to 30% by a culture approach). Also, no real-time PCR-negative samples were found positive by culturing. A. salmonicida was detected by real-time PCR, though not by culturing, in freshwater fish showing no signs of furunculosis, indicating possible presence of carrier fish. In seawater fish examined after an outbreak and antibiotics treatment, real-time PCR showed the presence of the bacterium in all examined organs (1-482 genomic units mg(-1) ). With a limit of detection of 40 target copies (1-2 genomic units) per reaction, a high reproducibility and an excellent efficiency, the present real-time PCR assay provides a sensitive tool for the detection of A. salmonicida. © 2016 John Wiley & Sons Ltd.

  13. Type III secretion system of Aeromonas salmonicida undermining the host’s immune response

    Directory of Open Access Journals (Sweden)

    Joachim Frey

    2016-07-01

    Full Text Available Aeromonas salmonicida subsp. salmonicida is an important pathogen in salmonid aquaculture and is responsible for furunculosis, a common infectious disease in salmon, trout and char. The type-three secretion system (T3SS is considered as the major virulence attribute of A. salmonicida. It is used by the bacterium to secrete and translocate a large number of toxins and effector proteins into the host cell. Some of these factors such as the bi-functional ADP ribosylating – GTPase activating protein AexT have been shown to have a detrimental impact on the integrity of the cell cytoskeleton, and hence contribute to impair phagocytosis. Other effector proteins that are injected to the host cell such as AopP act by inhibiting the NF-κB signalling pathway blocking the translocation of NF-κB (p65 into the nucleus, thus influencing the host’s inflammatory response. Several additional effectors that are secreted and translocated via the T3SS including Ati2, AopN and ExsE have been suggested to modulate the host’s immune response in particular by down regulating the inflammatory reaction. The analysis of the immune response in rainbow trout (Oncorhynchus mykiss infected with virulent, T3SS harbouring A. salmonicida subsp. salmonicida revealed that the infection leads to a rapid and strong downregulation of several immune-relevant markers affecting both the innate and the adaptive immune response, leading to mortality of the infected fish. In contrast, infection with a T3SS deficient mutant causes a normal immune reaction and clearing of the pathogen. These findings show that T3SS-delivered effector molecules and toxins of A. salmonicida do not only impair the host’s cytoskeleton thus damaging cell physiology and phagocytosis, but also affect the transcription of critical immune markers including the shut-down of important warning signals to recognize infection and induce immune defense.

  14. Growth inhibition of Aeromonas salmonicida and Yersinia ruckeri by disinfectants containing peracetic acid.

    Science.gov (United States)

    Meinelt, Thomas; Phan, Thy-My; Behrens, Sascha; Wienke, Andreas; Pedersen, Lars-Flemming; Liu, Dibo; Straus, David L

    2015-04-08

    Peracetic acid (PAA) is a therapeutic agent used for disinfection in aquaculture, but it must be investigated thoroughly in order to mitigate diseases without harming the fish. Successful disinfectants (like PAA) should not leave dangerous residues in the environment in order to successfully contribute to sustainable aquaculture. The aim of our study was to compare the effectiveness of 6 commercial PAA products with different molecular PAA:H2O2 ratios to reduce bacterial growth of Aeromonas salmonicida and Yersinia ruckeri and to determine effective concentrations and exposure times. All products reduced colony-forming units (CFUs) of A. salmonicida and Y. ruckeri. Products with higher molecular PAA:H2O2 ratios inhibited growth better than products with lower molecular PAA:H2O2 ratios at the same PAA concentration; this indicates that H2O2 is not the driving force in the reduction of A. salmonicida and Y. ruckeri growth by PAA in vitro. The practical application of the products with high molecular PAA:H2O2 ratios should be prioritized if these pathogens are diagnosed.

  15. Protection against atypical Aeromonas salmonicida infection in carp (Cyprinus carpio L.) by oral administration of humus extract.

    Science.gov (United States)

    Kodama, Hiroshi; Denso; Nakagawa, Tsuyoshi

    2007-04-01

    Humic substances are formed during the decomposition of organic matter in humus, and are found in many natural environments in which organic materials and microorganisms have been present. In the present study, oral administration of humus extract to common carp (Cyprinus carpio L.) induced effective protection against experimental atypical Aeromonas salmonicida infection. Mortality of fish and development of skin lesions such as hemorrhages and ulcers were significantly suppressed in carp treated with 10%, 5% or 1% humus extract adsorbed on dry feeding pellets. The median surviving days was also greater in fish treated with 10% or 5% humus extract than in untreated fish. Atypical A. salmonicida was isolated from ulcerative lesions of part of dead fish, but Aeromonas hydrophila and Flavobacterium sp. were also isolated from these fish, verifying bacterial population changes during the progression of skin lesions. These results clearly show that treatment of fish with humus extract is effective in preventing A. salmonicida disease.

  16. Polymerase chain reaction (PCR)-based typing analysis of atypical isolates of the fish pathogen Aeromonas salmonicida

    DEFF Research Database (Denmark)

    Høie, S.; Dalsgaard, Inger; Aase, I.L.;

    1999-01-01

    Two hundred and five isolates of atypical Aeromonas salmonicida, recovered from a wide range of hosts and countries were characterized by polymerase chain reaction (PCR) targeting four genes. The chosen genes were those encoding the extracellular A-layer protein (AP), the serine protease (Sprot...

  17. Occurrence and significance of atypical Aeromonas salmonicida in non-salmonid and salmonid fish species : A review

    DEFF Research Database (Denmark)

    Wiklund, T.; Dalsgaard, Inger

    1998-01-01

    information is available about the ecology, spread and survival of atypical strains in water. The commonly used therapeutic methods for the control of diseases in farmed fish caused by atypical A. salmonicida are generally effective against the atypical strains. Resistance to different antibiotics......Bacterial strains of Aeromonas salmonicida included in the recognized subsp. achromogenes, subsp, masoucida, and subsp. smithia in addition to the large number of strains not included in any of the described subspecies are referred to as atypical A. salmonicida. The atypical strains form a very....... The best known diseases associated with atypical A. salmonicida are carp Cyprinus carpio erythrodermatitis, goldfish Carassius auratus ulcer disease, and ulcer disease of flounder Platichthys flesus, but atypical strains are apparently involved in more disease outbreaks than previously suspected...

  18. Occurrence and significance of atypical Aeromonas salmonicida in non-salmonid and salmonid fish species: a review.

    Science.gov (United States)

    Wiklund, T; Dalsgaard, I

    1998-02-26

    Bacterial strains of Aeromonas salmonicida included in the recognized subsp. acromogenes, subsp. masoucida, and subsp. smithia in addition to the large number of strains not included in any of the described subspecies are referred to as atypical A. salmonicida. The atypical strains form a very heterogeneous group with respect to biochemical characteristics, growth conditions, and production of extracellular proteasess. Consequently, the present taxonomy of the species A. salmonicida is rather ambiguous. Atypical A. salmonicida has been isolated from a wide range of cultivated and wild fish species, non-salmonids as well as salmonids, inhabiting fresh water, brackish water and marine environments in northern and central Europe, South Africa, North America, Japan and Australia. In non-salmonid fish species, infections with atypical strains often manifest themselves as superficial skin ulcerations. The best known diseases associated with atypical A. salmonicida are carp Cyprinus carpio erythrodermatitis, goldfish Carassius auratus ulcer disease, and ulcer disease of flounder Platichthys flesus, but atypical strains are apparently involved in more disease outbreaks than previously suspected. Macroscopical and microscopical studies of ulcerated fish indicate internal organs are infrequently invaded by atypical A. salmonicida. This view is supported by the fact that atypical strains are irregularly isolated from visceral organs of ulcerated fish. High mortality caused by atypical A. salmonicida has been observed in populations of wild non-salmonids and farmed salmonids, although the association between the mortality in the wild fish stocks and atypical A. salmonicida has not always been properly assessed. In injection experiments the pathogenicity of the atypical strains examined showed large variation. An extacellular A-layer has been detected in different atypical strains, but virulence mechanisms different from those described for (typical) A. salmonicida subsp

  19. A novel challenge method with Aeromonas salmonicida in rainbow trout for evaluation of furunculosis vaccines

    DEFF Research Database (Denmark)

    Marana, Moonika Haahr; Skov, Jakob; Chettri, Jiwan Kumar

    Challenge methods used to induce furunculosis in rainbow trout when testing the potency of vaccines may include exposure to Aeromonas salmonicida by intraperitoneal injection, cohabitation or bath immersion. Intraperitoneal injection is effective but will not reflect systemic immunity because...... inflammatory cells at the vaccine injection site may combat injected bacteria fast. The cohabitation and bath immersion methods both mimic the natural infection route but are less effective in inducing the disease. We have tested a new challenge method mimicking that rainbow trout in fish farms might...... to be efficient in inducing a more natural disease progression in fish and a stable mortality. The method could differentiate efficacies of different vaccines with regard to adjuvant formulations and content of antigen....

  20. Quorum sensing in Aeromonas salmonicida subsp. achromogenes and the effect of the autoinducer synthase AsaI on bacterial virulence

    DEFF Research Database (Denmark)

    Schwenteit, Johanna; Gram, Lone; Nielsen, Kristian Fog

    2011-01-01

    The Gram-negative fish pathogenic bacterium Aeromonas salmonicida possesses the LuxIRtype quorum sensing (QS) system, termed AsaIR. In this study the role of QS in A. salmonicida subsp. achromogenes virulence and pigment production was investigated. Five wild-type Asa strains induced the N......Ideficient mutant was 20-fold higher than that of the isogenic wt strain and the mean day to death of the mutant was significantly prolonged. Furthermore, the expression of two virulence factors (a toxic protease, AsaP1, and a cytotoxic factor) and a brown pigment were reduced in the mutant. AsaP1 productionwas...... inhibited by synthetic QS inhibitors (N- (propylsulfanylacetyl)-L-homoserine lactone; N-(pentylsulfanylacetyl)-L-homoserine lactone; and N-(heptylsulfanylacetyl)-L-homoserine lactone) at concentrations that did not affect bacterial growth. It is a new finding that the AHL synthase of Aeromonas affects...

  1. Comparative evaluation of infection methods and environmental factors on challenge success: Aeromonas salmonicida infection in vaccinated rainbow trout.

    Science.gov (United States)

    Chettri, Jiwan Kumar; Skov, Jakob; Jaafar, Rzgar M; Krossøy, Bjørn; Kania, Per W; Dalsgaard, Inger; Buchmann, Kurt

    2015-06-01

    When testing vaccine-induced protection an effective and reliable challenge method is a basic requirement and we here present a comparative study on different challenge methods used for infection of rainbow trout Oncorhynchus mykiss with Aeromonas salmonicida, a bacterial pathogen eliciting furunculosis. Fish were vaccinated with three different adjuvanted trivalent vaccines containing formalin killed A. salmonicida, Vibrio anguillarum O1 and O2a. These were 1) the commercial vaccine Alpha Ject 3000, 2) an experimental vaccine with water in paraffin oil adjuvant, 3) an experimental vaccine with water in paraffin oil in water adjuvant. Fish were then exposed to A. salmonicida challenge using i.p. injection, cohabitation in freshwater, cohabitation in saltwater (15 ppt) or combined fresh/saltwater cohabitation. Cohabitation reflects a more natural infection mode and was shown to give better differentiation of vaccine types compared to i.p. injection of live bacteria. The latter infection mode is less successful probably due to the intra-abdominal inflammatory reactions (characterized in this study according to the Speilberg scale) induced by i.p. vaccination whereby injected live bacteria more effectively become inactivated at the site of injection. Compared to cohabitation in freshwater, cohabitation in saltwater was less efficient probably due to reduced survivability of A. salmonicida in saltwater, which was also experimentally verified in vitro.

  2. Antimicrobial effect of the Biotronic® Top3 supplement and efficacy in protecting rainbow trout (Oncorhynchus mykiss) from infection by Aeromonas salmonicida subsp. salmonicida.

    Science.gov (United States)

    Menanteau-Ledouble, Simon; Krauss, Ines; Goncalves, Rui Alexandre; Weber, Barbara; Santos, Gonçalo Abreu; El-Matbouli, Mansour

    2017-03-18

    Demand for more environmentally friendly practices have led to the adoption of several feed supplements by the fish farming industry. In the present study, we investigated a commercially available formula that includes a mixture of three compounds: organic acids, a phytochemical and Biomin® Permeabilizing Complex. This mixture demonstrated antimicrobial properties in vitro and was able to inhibit growth of multiple species of aquatic bacterial pathogens, including Aeromonas salmonicida. Bacterial challenge was performed using A. salmonicida and three exposure routes: intra-peritoneal injection, immersion, and cohabitation. Mortality rates following infection by injection were significantly decreased in the fish that had received the supplemented feed. Fish infected through the other routes did not show a significant difference in mortality. In term of farming performance, while the fish that had received the feed supplement showed an improvement in weight gain and final weight, these changes were not found to be statistically significant. Similarly, no significant difference was observed in the feed conversion ratio. The results of this study suggest that this feed supplement may be effective at protecting rainbow trout from fish furunculosis.

  3. Potential role of specific antibodies as important vaccine induced protective mechanism against Aeromonas salmonicida in rainbow trout.

    Directory of Open Access Journals (Sweden)

    Kasper Rømer Villumsen

    Full Text Available Furunculosis caused by infection with Aeromonas salmonicida subsp. salmonicida has been a known threat to aquaculture for more than a century. Efficient prophylactic approaches against this disease are essential for continued growth of salmonid aquaculture. Since the introduction of successful oil-adjuvanted vaccines in the early 1990's, a number of studies have been published on the protective as well as adverse effects of these vaccines. Most studies focus on vaccination of salmon (Salmo salar. However, rainbow trout (Oncorhynchus mykiss are also very susceptible to infection and are vaccinated accordingly. In this study we have examined the protection against infection with a Danish strain of A. salmonicida in both vaccinated and non-vaccinated rainbow trout. A commercial and an experimental auto-vaccine were tested. The protective effects of the vaccines were evaluated through an A. salmonicida challenge 18 weeks post vaccination. Both vaccines resulted in a significantly increased survival in the vaccinated fish during a 28 day challenge period relative to non-vaccinated fish (P = 0.01 and P = 0.001 for the commercial and experimental vaccine, respectively. Throughout the entire experiment, the presence of specific antibodies in plasma was monitored using ELISA. A significant increase in specific antibody levels was seen in fish vaccinated with both vaccines during the 18 weeks between vaccination and challenge. Within 3 days post challenge, a significant decrease in specific antibodies occurred in vaccinated fish. A positive correlation was found between mean levels of specific antibodies pre challenge and overall survival. This correlation, along with the observed depletion of antibodies during the initial phase of infection, suggests that specific antibodies play an essential role in vaccine mediated protection against A. salmonicida in rainbow trout.

  4. Characterization of class 1 integrons associated with R-plasmids in clinical Aeromonas salmonicida isolates from various geographical areas

    DEFF Research Database (Denmark)

    Schmidt, A.S.; Bruun, Morten Sichlau; Larsen, J.L.;

    2001-01-01

    Class 1 integrons were found in 26 of 40 antibiotic-resistant isolates of the fish pathogen Aeromonas salmonicida from Northern Europe and North America. Three different dhfr genes, conferring trimethoprim resistance, and one ant(3 " )1a aminoglycoside resistance gene were identified as gene...... inserts. The gene cassettes tended to be conserved among isolates from a particular geographical area. Nineteen isolates transferred R- plasmids carrying different tet determinants to Escherichia coli in filter mating assays, and in 15 cases, the class 1 integrons were co-transferred. Transferable...

  5. The Aeromonas salmonicida subsp. salmonicida exoproteome: determination of the complete repertoire of Type-Three Secretion System effectors and identification of other virulence factors.

    Science.gov (United States)

    Vanden Bergh, Philippe; Heller, Manfred; Braga-Lagache, Sophie; Frey, Joachim

    2013-09-27

    Aeromonas salmonicida subsp. salmonicida, the etiologic agent of furunculosis, is a major pathogen of fisheries worldwide. Several virulence factors have been described, but the type-three secretion system (T3SS) is recognized as having a major effect on virulence by injecting effectors directly into fish cells. In this study we used high-throughput proteomics to display the differences between in vitro secretome of A. salmonicida wild-type (wt, hypervirulent, JF2267) and T3SS-deficient (isogenic ΔascV, extremely low-virulent, JF2747) strains in exponential and stationary phases of growth. Results confirmed the secretion of effectors AopH, AexT, AopP and AopO via T3SS, and for the first time demonstrated the impact of T3SS in secretion of Ati2, AopN and ExsE that are known as effectors in other pathogens. Translocators, needle subunits, Ati1, and AscX were also secreted in supernatants (SNs) dependent on T3SS. AopH, Ati2, AexT, AopB and AopD were in the top seven most abundant excreted proteins. EF-G, EF-Tu, DnaK, HtpG, PNPase, PepN and MdeA were moderately secreted in wt SNs and predicted to be putative T3 effectors by bioinformatics. Pta and ASA_P5G088 were increased in wt SNs and T3-associated in other bacteria. Ten conserved cytoplasmic proteins were more abundant in wt SNs than in the ΔascV mutant, but without any clear association to a secretion system. T1-secreted proteins were predominantly found in wt SNs: OmpAI, OmpK40, DegQ, insulinase ASA_0716, hypothetical ASA_0852 and ASA_3619. Presence of T3SS components in pellets was clearly decreased by ascV deletion, while no impact was observed on T1- and T2SS. Our results demonstrated that the ΔascV mutant strain excreted well-described (VapA, AerA, AerB, GCAT, Pla1, PlaC, TagA, Ahe2, GbpA and enolase) and yet uncharacterized potential toxins, adhesins and enzymes as much as or even more than the wt strain. Other putative important virulence factors were not detected. We demonstrated the whole in vitro

  6. Quorum sensing signals are produced by Aeromonas salmonicida and quorum sensing inhibitors can reduce production of a potential virulence factor

    DEFF Research Database (Denmark)

    Rasch, Maria; Kastbjerg, Vicky Gaedt; Bruhn, Jesper Bartholin

    2007-01-01

    . Pigment production was only observed in broth under highly aerated conditions. Quorum sensing inhibitors (QSIs) are compounds that specifically block QS systems without affecting bacterial growth and 2 such compounds, sulphur-containing AHL-analogues, reduced production of protease in a typical strain...... of Aeromonas salmonicida strains. All 31 typical strains were AHL producers as were 21 of 26 atypical strains, but on a strain population basis, production of virulence factors such as protease, lipase, A-layer or pigment did not correlate with the production and accumulation of AHLs in the growth medium...... of these were completely down regulated by HepS-AHL. Hence, QSIs can curb virulence in some strains and could potentially be pursued as bacterial disease control measures in aquaculture....

  7. Polymerase chain reaction (PCR)-based typing analysis of atypical isolates of the fish pathogen Aeromonas salmonicida

    DEFF Research Database (Denmark)

    Høie, S.; Dalsgaard, Inger; Aase, I.L.

    1999-01-01

    Two hundred and five isolates of atypical Aeromonas salmonicida, recovered from a wide range of hosts and countries were characterized by polymerase chain reaction (PCR) targeting four genes. The chosen genes were those encoding the extracellular A-layer protein (AP), the serine protease (Sprot......), the glycerophospholipid:cholestrol acetyltransferase protein (GCAT), and the 16S rRNA (16S rDNA). All the atypical A. salmonicida isolates could be assigned to 4 PCR groups. Group 1 comprised 45 strains which rested positive for PCR amplification, using the 16S rDNA, GCAT2, Sprot2, and AP primer-sets. Group 2 comprised...... 88 strains with produced PCR products using the 16S rDNA, GCAT2 and AP primer-sets. Group 3 comprised 21 strains which produced PCR products using 16S rDNA, GCAT2 and Sprot2 primer-sets, and group 4 comprised 51 strains which produced PCR products using the 16S rDNA and GCAT2 primer-sets only. A...

  8. Recovery of a fish pathogenic bacterium, Aeromonas salmonicida, from ebonyshell mussels Fusconaia ebena using nondestructive sample collection procedures

    Science.gov (United States)

    Starliper, C.E.

    2008-01-01

    Refugia are increasingly being used to maintain and propagate imperiled freshwater mussels for future population augmentations. Success for this endeavor is dependent on good husbandry, including a holistic program of resource health management. A significant aspect to optimal health is the prevention or control of infectious diseases. Describing and monitoring pathogens and diseases in mussels involves examination of tissues or samples collected from an appropriate number of individuals that satisfies a certain confidence level for expected prevalences of infections. In the present study, ebonyshell mussels Fusconaia ebena were infected with a fish pathogenic bacterium, Aeromonas salmonicida, through their cohabitation with diseased brook trout Salvelinus fontinalis. At a 100% prevalence of infection, the F. ebena were removed from the cohabitation tank to clean tanks that were supplied with pathogen-free water, which initiated their depuration of A. salmonicida. Three samples (nondestructive fluid, mantle, hemolymph) collected using nondestructive procedures were compared with fluids and soft tissue homogenates collected after sacrificing the mussels for recovery of the bacterium during this period of depuration. Nondestructive sample collections, especially ND fluid, provide a comparable alternative to sacrificing mussels to determine pathogen status.

  9. Different immunization routes induce protection against Aeromonas salmonicida through different immune mechanisms in rainbow trout

    DEFF Research Database (Denmark)

    Villumsen, Kasper Rømer; Raida, Martin Kristian

    in fish immunology and vaccinology, resulting in the development of both oral, immersion and injectable vaccine strategies over time. Applying mineral oil adjuvants, injectable vaccines inducing high levels of protection in salmon (Salmo salar) rose to prominence in the 1990’s. In general injectable......, adjuvanted vaccines have been shown to induce long-lasting increases in specific antibody levels. In general the majority of the published work concerning vaccination against A. salmonicida has been conducted on salmon. Using injectable oil-adjuvanted vaccines, we have previously shown that the induced level...

  10. Transcription factor T-bet in Atlantic salmon: Characterization and gene expression in mucosal tissues during Aeromonas salmonicida infection

    Directory of Open Access Journals (Sweden)

    Jaya eKumari

    2015-07-01

    Full Text Available The T-box transcription factor T-bet is expressed in a number of hematopoietic cell types in mammals and plays an essential role in the lineage determination of Th1 T-helper cells and is considered as an essential feature for both innate and adaptive immune responses in higher vertebrates. In the present study, we have identified and characterized the full-length Atlantic salmon T-bet cDNA (3502 bp. The putative primary structure of the polypeptide deduced from the cDNA sequence contained 612 aa, which possessed a T-box DNA binding domain. Phylogenetic study and gene synteny revealed it is a homologue to mammalian T-bet. Quantitative PCR analysis of different tissues in healthy fish showed that salmon T-bet gene was highly expressed in spleen, followed by head kidney, and was expressed in intestine, skin, and liver at lower levels. Moreover, the time dependent expression profile of T-bet, interferon gamma (IFNγ, interleukin-22 (IL-22, and NKEF (Natural killer enhancement factor in mucosal tissues during waterborne infection with live Aeromonas salmonicida, indicated the involvement of T-bet in mucosal immune response in Atlantic salmon.

  11. Transcription Factor T-Bet in Atlantic Salmon: Characterization and Gene Expression in Mucosal Tissues during Aeromonas Salmonicida Infection.

    Science.gov (United States)

    Kumari, Jaya; Zhang, Zuobing; Swain, Trilochan; Chi, Heng; Niu, Cuijuan; Bøgwald, Jarl; Dalmo, Roy Ambli

    2015-01-01

    The T-box transcription factor T-bet is expressed in a number of hematopoietic cell types in mammals and plays an essential role in the lineage determination of Th1 T-helper cells and is considered as an essential feature for both innate and adaptive immune responses in higher vertebrates. In the present study, we have identified and characterized the full-length Atlantic salmon T-bet cDNA (3502 bp). The putative primary structure of the polypeptide deduced from the cDNA sequence contained 612 aa, which possessed a T-box DNA binding domain. Phylogenetic study and gene synteny revealed it is as a homolog to mammalian T-bet. Quantitative PCR analysis of different tissues in healthy fish showed that salmon T-bet gene was highly expressed in spleen, followed by head kidney, and was expressed in intestine, skin, and liver at lower levels. Moreover, the time-dependent expression profile of T-bet, interferon gamma (IFNγ), interleukin-22 (IL-22), and natural killer enhancement factor in mucosal tissues during water-borne infection with live Aeromonas salmonicida, indicated the involvement of T-bet in mucosal immune response in Atlantic salmon.

  12. Effects of dietary linseed oil on innate immune system of Eurasian perch and disease resistance after exposure to Aeromonas salmonicida achromogen.

    Science.gov (United States)

    Geay, F; Mellery, J; Tinti, E; Douxfils, J; Larondelle, Y; Mandiki, S N M; Kestemont, P

    2015-12-01

    This study was designated to investigate the effects of dietary fish oil (FO diet) replacement by linseed oil (LO diet) on regulation of immune response and disease resistance in Eurasian perch (Perca fluviatilis). A control diet containing fish oil (FO = cod liver oil) and characterized by high levels of n-3 high LC-PUFA (6% EPA, 7.5% of total fatty acids (FAs)) was compared to linseed oil diet (LO diet) composed of low LC-PUFA contents (1% EPA, 2.3% DHA of total FAs) but high C18 fatty acids levels. The experiment was conducted in quadruplicate groups of 80 fish each. After 10 weeks of feeding, the innate immune status was evaluated in various organs (liver, spleen, and head-kidney) (feeding condition). Two days later, a bacterial challenge was performed on fish from 2 rearing conditions: fish infected with Aeromonas salmonicida (bacteria condition) and fish injected with sterile medium but maintained in the same flow system that fish challenged with bacteria (sentinel condition). Three days after injection of bacteria, a significant decrease of lymphocyte, thrombocyte and basophil populations was observed while neutrophils were not affected. In addition, plasma lysozyme activity and reactive oxygen species production in kidney significantly increased in fish challenged with A. salmonicida while the plasma alternative complement pathway activity was not affected. Increase of plasma lysozyme activity as well as reactive oxygen species production in spleen and kidney of sentinel fish suggest that these immune defenses can also be activated, but at lower bacteria concentration than infected fish. No differences in leucocyte populations, plasma lysozyme and alternative complement pathway activities were observed between dietary treatments. Similarly, expression of genes related to eicosanoid synthesis in liver were not affected by the dietary oil source but were strongly stimulated in fish challenged with A. salmonicida. These findings demonstrated that the use of

  13. Efficacy of an extract from garlic, Allium sativum, against infection with the furunculosis bacterium, Aeromonas salmonicida, in rainbow trout, Oncorhynchus mykiss

    Science.gov (United States)

    Breyer, Kate E.; Getchell, Rodman G.; Cornwell, Emily R.; Wooster, Gregory A.; Ketola, H. George; Bowser, Paul R.

    2015-01-01

    Juvenile rainbow trout, Oncorhynchus mykiss, were fed diets containing 0, 0.5, 1.0, and 2.0% of a garlic extract, challenged with a modified 50% lethal dose of Aeromonas salmonicida and monitored for 28 d. There were significant increases in survival of trout fed 0.5 and 1.0% garlic extract as compared to the control and 2.0% garlic extract groups. A target animal safety study was performed at varying increments using the target dose of 0.5% garlic extract at 0× (0% garlic extract), 1× (0.5% garlic extract), 3× (1.5% garlic extract), and 5× (2.5% garlic extract) for 3× (6 wk) the duration of the original study. There was a significant increase in the level of circulating lymphocytes and a significant decrease in the level of circulating monocytes. The latter correlated to an increased level of pigment-containing macrophage centers within the renal tissue as garlic extract dosing increased, denoting a potential deleterious inflammatory effect as macrophage infiltration became severe at the highest dose. These studies suggest that feeding low-dose (0.5% or 1.0%) garlic extract improves survivability in rainbow trout when challenged with A. salmonicida and appears safe; however, higher levels do not appear to be effective and may cause deleterious effects on health.

  14. Potential Role of Specific Antibodies as Important Vaccine Induced Protective Mechanism against Aeromonas salmonicida in Rainbow Trout

    DEFF Research Database (Denmark)

    Rømer Villumsen, Kasper; Dalsgaard, Inger; Holten-Andersen, Lars;

    2012-01-01

    -adjuvanted vaccines in the early 1990's, a number of studies have been published on the protective as well as adverse effects of these vaccines. Most studies focus on vaccination of salmon (Salmo salar). However, rainbow trout (Oncorhynchus mykiss) are also very susceptible to infection and are vaccinated accordingly....... In this study we have examined the protection against infection with a Danish strain of A. salmonicida in both vaccinated and non-vaccinated rainbow trout. A commercial and an experimental auto-vaccine were tested. The protective effects of the vaccines were evaluated through an A. salmonicida challenge 18...

  15. Detection and quantification of Aeromonas salmonicida in fish tissue by real-time PCR

    DEFF Research Database (Denmark)

    Bartkova, Simona; Kokotovic, Branco; Skall, H. F.

    2017-01-01

    fish by real-time PCR compared to 30% by a culture approach). Also, no real-time PCR-negative samples were found positive by culturing. A. salmonicida was detected by real-time PCR, though not by culturing, in freshwater fish showing no signs of furunculosis, indicating possible presence of carrier...... developed real-time PCR assay targeting the plasmid encoded aopP gene of A. salmonicida was, in parallel with culturing, used for the examination of five organs of 40 fish from Danish freshwater and seawater farms. Real-time PCR showed overall a higher frequency of positives than culturing (65% of positive...... fish. In seawater fish examined after an outbreak and antibiotics treatment, real-time PCR showed the presence of the bacterium in all examined organs (1-482 genomic units mg-1). With a limit of detection of 40 target copies (1-2 genomic units) per reaction, a high reproducibility and an excellent...

  16. Comparative evaluation of infection methods and environmental factors on challenge success: Aeromonas salmonicida infection in vaccinated rainbow trout

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Skov, Jakob; Jaafar, Rzgar M.

    2015-01-01

    differentiation of vaccine types compared to i.p. injection of live bacteria. The latter infection mode is less successful probably due to the intra-abdominal inflammatory reactions (characterized in this study according to the Speilberg scale) induced by i.p. vaccination whereby injected live bacteria more...... effectively become inactivated at the site of injection. Compared to cohabitation in freshwater, cohabitation in saltwater was less efficient probably due to reduced survivability of A. salmonicida in saltwater, which was also experimentally verified in vitro....

  17. Aeromonas salmonicida Infection Only Moderately Regulates Expression of Factors Contributing to Toll-Like Receptor Signaling but Massively Activates the Cellular and Humoral Branches of Innate Immunity in Rainbow Trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Andreas Brietzke

    2015-01-01

    Full Text Available Toll-like receptors (TLRs are known to detect a defined spectrum of microbial structures. However, the knowledge about the specificity of teleost Tlr factors for distinct pathogens is limited so far. We measured baseline expression profiles of 18 tlr genes and associated signaling factors in four immune-relevant tissues of rainbow trout Oncorhynchus mykiss. Intraperitoneal injection of a lethal dose of Aeromonas salmonicida subsp. salmonicida induced highly increased levels of cytokine mRNAs during a 72-hour postinfection (hpi period. In contrast, only the fish-specific tlr22a2 and the downstream factor irak1 featured clearly increased transcript levels, while the mRNA concentrations of many other tlr genes decreased. Flow cytometry quantified cell trafficking after infection indicating a dramatic influx of myeloid cells into the peritoneum and a belated low level immigration of lymphoid cells. T and B lymphocytes were differentiated with RT-qPCR revealing that B lymphocytes emigrated from and T lymphocytes immigrated into head kidney. In conclusion, no specific TLR can be singled out as a dominant receptor for A. salmonicida. The recruitment of cellular factors of innate immunity rather than induced expression of pathogen receptors is hence of key importance for mounting a first immune defense against invading A. salmonicida.

  18. Presumptive and Definitive Identification of Aeromonas from infected Ornamental Gold fish (Carassius auratus auratus)

    OpenAIRE

    2013-01-01

    The paper deals with the presumptive identification of Aeromonas, definitive identification of two species of Aeromonas i.e. Aeromonas hydrophila, Aeromonas salmonicida in various organs of Gold fish infected with red disease.

  19. Steelhead trout Oncorhynchus mykiss metabolic rate is affected by dietary Aloe vera inclusion but not by mounting an immune response against formalin-killed Aeromonas salmonicida.

    Science.gov (United States)

    Zanuzzo, F S; Urbinati, E C; Nash, G W; Gamperl, A K

    2015-07-01

    The oxygen consumption (MO2) of two groups of 10° C acclimated steelhead trout Oncorhynchus mykiss was measured for 72 h after they were given a 100 µl kg(-1) intraperitoneal injection of formalin-killed Aeromonas salmonicida (ASAL) or phosphate-buffered saline (PBS). In addition, plasma cortisol levels were measured in fish from both groups prior to, and 1 and 3 h after, they were given a 30 s net stress. The first group was fed an unaltered commercial diet for 4 weeks, whereas the second group was fed the same diet but with 0·5% (5 g kg(-1) ) Aloe vera powder added; A. vera has potential as an immunostimulant for use in aquaculture, but its effects on basal and acute phase response (APR)-related metabolic expenditures and stress physiology, are unknown. Injection of ASAL v. PBS had no measurable effect on the MO2 of O. mykiss indicating that the APR in this species is not associated with any net increase in energy expenditure. In contrast, incorporating 0·5% A. vera powder into the feed decreased routine metabolic rate by c. 8% in both injection groups and standard metabolic rate in the ASAL-injected group (by c. 4 mg O2 kg(-1) h(-1) ; 5%). Aloe vera fed fish had resting cortisol levels that were approximately half of those in fish on the commercial diet (c. 2·5 v. 5·0 ng ml(-1) ), but neither this difference nor those post-stress reached statistical significance (P > 0·05).

  20. Diversidad intraespecífica y factores de virulencia en el “complejo de especies de Aeromonas hydrophila” (A. Hydrophila, A. Salmonicida, A. Bestiarum).

    OpenAIRE

    2013-01-01

    [spa] El género Aeromonas está constituido actualmente por 26 especies reconocidas, algunas de las cuales incluyen varias subespecies. Son habitantes ubicuos del agua dulce, pero también de aguas cloradas, salobres y marinas. Se han obtenido cepas de Aeromonas de una amplia variedad de alimentos, y se han aislado de muestras clínicas. Algunas especies de Aeromonas son causantes de infecciones intestinales y extraintestinales aunque los mecanismos por los que causan diarreas bacterianas no ...

  1. Bactericidal activity of juvenile chinook salmon macrophages against Aeromonas salmonicida after exposure to live or heat-killed Renibacterium salmoninarum or to soluble proteins produced by R. salmoninarum

    Science.gov (United States)

    Siegel, D.C.; Congleton, J.L.

    1997-01-01

    Macrophages isolated from the anterior kidney of juvenile chinook salmon Oncorhynchus tshawytscha in 96-well microtiter plates were exposed for 72 h to 0, 105, or 106 live or heat-killed Renibacterium salmoninarum cells per well or to 0, 0.1, 1.0, or 10 ??g/mL of R. salmoninarum soluble proteins. After treatment, the bactericidal activity of the macrophages against Aerornonas salmonicida was determined by a colorimetric assay based on the reduction of the tetrazolium dye MTT to formazan by viable bacteria. The MTT assay was modified to allow estimation of the percentage of bacteria killed by reference to a standard curve relating the number of bacteria added to microtiter wells to absorbance by formazan at 600 nm. The live and heat-killed R. salmoninarum treatments significantly (P < 0.001) increased killing of A. salmonicida by chinook salmon macrophages. In each of the five trials, significantly (P < 0.05) greater increases in killing occurred after exposure to 105 R. salmoninarum cells than to 106 R. salmoninarum cells per well. In contrast, treatment of macrophages with 10 ??g/mL R. salmoninarum soluble proteins significantly (P < 0.001) decreased killing of A. salmonicida, but treatment with lower doses did not. These results show that the bactericidal activity of chinook salmon macrophages is stimulated by exposure to R. salmoninarum cells at lower dose levels but inhibited by exposure to R. salmoninarum cells or soluble proteins at higher dose levels.

  2. Histopathological findings in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with 3 different Aeromonas species.

    Science.gov (United States)

    Zepeda-Velázquez, Andrea Paloma; Vega-Sánchez, Vicente; Salgado-Miranda, Celene; Soriano-Vargas, Edgardo

    2015-07-01

    This study describes the macroscopic and microscopic lesions in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with genetically identified Aeromonas salmonicida, A. hydrophila, and A. veronii species. The genus Aeromonas includes bacteria that naturally inhabit both waterways and organisms. At least 27 Aeromonas species have been identified to date, some of which can cause significant economic losses in aquaculture. As up to 68.8% of Aeromonas isolates may be misidentified in routine biochemical and phenotypic tests, however, reported cases of Aeromonas infection in fish may be wrongly identified. Our findings confirmed that the 3 Aeromonas species studied are associated with septicemia and dermal lesions in rainbow trout.

  3. The impacts of Aeromonas salmonicida on swimming behavior and numbers of blood cells of Atlantic salmon (Salmo salar L.)%杀鲑气单胞菌对大西洋鲑游泳行为和血细胞数量的影响

    Institute of Scientific and Technical Information of China (English)

    衣萌萌; 孙国祥; 杜以帅; 刘鹰; 王顺奎; 于凯松

    2015-01-01

    为探讨利用鱼类行为及血细胞数量变化预警杀鲑气单胞菌(Aeromonas salmonicida)病害发生的可行性,监测了生产中感染杀鲑气单胞菌的大西洋鲑(Salmo salar L.)的游泳行为,以及杀鲑气单胞菌攻毒后大西洋鲑血细胞数量的变化。实验采用同一养殖基地和同一批次的大西洋鲑,其中现场实验鱼选自生产车间健康的和感染杀鲑气单胞菌的养殖鱼,攻毒实验中处理组实验鱼每尾背肌注射100µL、浓度为3.05×107CFU/mL的菌液,对照组注射等体积灭菌生理盐水。现场实验表明,感染杀鲑气单胞菌的大西洋鲑临界游泳速度较健康鱼低26.7%(P<0.05),摆尾频率与游泳速度的线性回归方程的斜率也存在显著差异(P<0.05)。攻毒实验表明,从攻毒的第4天开始,处理组大西洋鲑白细胞、淋巴细胞、单核细胞和粒细胞数量较对照组均发生显著变化,其中第6天的变化最为显著,白细胞总数、粒细胞数分别降低了2.8%和43.9%(P<0.05),淋巴细胞数及单核细胞数分别升高了63.3%和23.9%(P<0.05),且处理组4种血细胞数随时间呈现显著的线性变化(P<0.05)。研究结果表明通过监测大西洋鲑游泳行为(临界游泳速度和摆尾频率)以及血细胞相关指标的变化可快速判断其健康状况,为病害的早期预警提供依据。%We investigated the feasibility of monitoring the health of Atlantic salmon (Salmo salar L.) to facilitate development of an early warning system for disease. To do this, we recorded changes in the swimming behavior and blood composition in the salmon after challenge with Aeromonas salmonicida. The fish used for the in situ challenge experiments were the same batch from the same farm. Healthy fish and fish infected with A. salmonicida were used for the in situ experiments. Salmon were injected in the dorsal muscle with 100 µL of A. salmonicida at 3.05×107 colony forming units (CFU)/mL per fish

  4. Aeromonas phages encode tRNAs for their overused codons.

    Science.gov (United States)

    Prabhakaran, Ramanandan; Chithambaram, Shivapriya; Xia, Xuhua

    2014-01-01

    The GC-rich bacterial species, Aeromonas salmonicida, is parasitised by both GC-rich phages (Aeromonas phages - phiAS7 and vB_AsaM-56) and GC-poor phages (Aeromonas phages - 25, 31, 44RR2.8t, 65, Aes508, phiAS4 and phiAS5). Both the GC-rich Aeromonas phage phiAS7 and Aeromonas phage vB_AsaM-56 have nearly identical codon usage bias as their host. While all the remaining seven GC-poor Aeromonas phages differ dramatically in codon usage from their GC-rich host. Here, we investigated whether tRNA encoded in the genome of Aeromonas phages facilitate the translation of phage proteins. We found that tRNAs encoded in the phage genome correspond to synonymous codons overused in the phage genes but not in the host genes.

  5. Effectiveness of radiation processing in elimination of Aeromonas from food

    Energy Technology Data Exchange (ETDEWEB)

    Nagar, Vandan [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Bandekar, Jayant R., E-mail: jrb@barc.gov.i [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2011-08-15

    Genus Aeromonas has emerged as an important human pathogen because it causes a variety of diseases including gastroenteritis and extra-intestinal infections. Contaminated water, sprouts, vegetables, seafood and food of animal origin have been considered to be the important sources of Aeromonas infection. In the present study, radiation sensitivity of indigenous strains of Aeromonas spp. from different food samples was evaluated. The decimal reduction dose (D{sub 10}) values of different Aeromonas isolates in saline at 0-4 {sup o}C were in the range of 0.031-0.046 kGy. The mixed sprouts, chicken and fish samples were inoculated with a cocktail of five most resistant isolates (A. salmonicida Y567, A. caviae A85, A. jandaei A514A, A. hydrophila CECT 839{sup T} and A. veronii Y47) and exposed to {gamma} radiation to study the effectiveness of radiation treatment in elimination of Aeromonas. D{sub 10} values of Aeromonas cocktail in mixed sprouts, chicken and fish samples were found to be 0.081{+-}0.001, 0.089{+-}0.003 and 0.091{+-}0.003 kGy, respectively. Radiation treatment with a 1.5 kGy dose resulted in complete elimination of 10{sup 5} CFU/g of Aeromonas spp. from mixed sprouts, chicken and fish samples. No recovery of Aeromonas was observed in the 1.5 kGy treated samples stored at 4 {sup o}C up to 12 (mixed sprouts) and 7 days (chicken and fish samples), even after enrichment and selective plating. This study demonstrates that a 1.5 kGy dose of irradiation treatment could result in complete elimination of 10{sup 5} CFU/g of Aeromonas spp. from mixed sprouts, chicken and fish samples.

  6. Effectiveness of radiation processing in elimination of Aeromonas from food

    Science.gov (United States)

    Nagar, Vandan; Bandekar, Jayant R.

    2011-08-01

    Genus Aeromonas has emerged as an important human pathogen because it causes a variety of diseases including gastroenteritis and extra-intestinal infections. Contaminated water, sprouts, vegetables, seafood and food of animal origin have been considered to be the important sources of Aeromonas infection. In the present study, radiation sensitivity of indigenous strains of Aeromonas spp. from different food samples was evaluated. The decimal reduction dose (D10) values of different Aeromonas isolates in saline at 0-4 °C were in the range of 0.031-0.046 kGy. The mixed sprouts, chicken and fish samples were inoculated with a cocktail of five most resistant isolates (A. salmonicida Y567, A. caviae A85, A. jandaei A514A, A. hydrophila CECT 839T and A. veronii Y47) and exposed to γ radiation to study the effectiveness of radiation treatment in elimination of Aeromonas. D10 values of Aeromonas cocktail in mixed sprouts, chicken and fish samples were found to be 0.081±0.001, 0.089±0.003 and 0.091±0.003 kGy, respectively. Radiation treatment with a 1.5 kGy dose resulted in complete elimination of 105 CFU/g of Aeromonas spp. from mixed sprouts, chicken and fish samples. No recovery of Aeromonas was observed in the 1.5 kGy treated samples stored at 4 °C up to 12 (mixed sprouts) and 7 days (chicken and fish samples), even after enrichment and selective plating. This study demonstrates that a 1.5 kGy dose of irradiation treatment could result in complete elimination of 105 CFU/g of Aeromonas spp. from mixed sprouts, chicken and fish samples.

  7. Flavobacterium psychrophilum - Experimental challenge and immune response

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi

    use of antibiotics, further knowledge of the disease is needed. Previous studies focusing on various types of aquacultures demonstrated the presence of F. psychrophilum in all examined farms. The bacterium was demonstrated in gills, skin, internal organs and wounds both during RTFS outbreaks......) Establish an experimental infection model imitating natural infection, 2) examine the immune response in blood and selected organs, and 3) examine potential portals of entry for the bacterium. Previous experimental immersion-challenges involving F. psychrophilum have resulted in none or low mortality...... in rainbow trout fry, unless the fish are stressed or have their surface compromised through e.g. injuries to the skin. The effect of a range of hydrogen peroxide (H2O2) concentrations was tested on fry in order to assess mortality. An appropriate dose was subsequently combined with immersion in a diluted...

  8. Further Characterization of a Type III Secretion System (T3SS) and of a New Effector Protein from a Clinical Isolate of Aeromonas Hydrophila - Part I

    Science.gov (United States)

    A type III secretion system (T3SS)-associated cytotoxin, AexT, with ADP-ribosyltransferase activity and homology to Pseudomonas aeruginosa bifuncational toxins ExoT/S, was recently identified from a fish pathogen Aeromonas salmonicida. In this study, we reported the molecular cha...

  9. Comparative Genome Analysis Provides Insights into the Pathogenicity of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Dalsgaard, Inger

    2016-01-01

    Flavobacterium psychrophilum is a fish pathogen in salmonid aquaculture worldwide that causes cold water disease (CWD) and rainbow trout fry syndrome (RTFS). Comparative genome analyses of 11 F. psychrophilum isolates representing temporally and geographically distant populations were used to des...

  10. Molecular characterization of Shewanella and Aeromonas isolates associated with spoilage of Common carp (Cyprinus carpio).

    Science.gov (United States)

    Beaz-Hidalgo, Roxana; Agüeria, Daniela; Latif-Eugenín, Fadua; Yeannes, Maria I; Figueras, Maria J

    2015-01-01

    Storage in ice is a common way of preserving commercial fish species but some microorganisms can still contaminate and participate in the spoilage of the product; therefore, identification of potential harmful microbes is important. Thirteen colonies were isolated from common carp (Cyprinus carpio) that had been stored in ice, whose phenotypic identification revealed that they belonged to the genera Aeromonas (n = 5) and Shewanella (n = 8). Molecular genotyping with ERIC-PCR showed clonality only among two of the five Aeromonas isolates and for two groups (n = 3; n = 2) of the eight Shewanella isolates. Sequencing the rpoD gene showed that four Aeromonas isolates belonged to the species Aeromonas salmonicida and one to A. sobria. Of the eight Shewanella, seven isolates cluster with Shewanella putrefaciens and one with Shewanella profunda in the 16S rRNA phylogenetic tree. However, analysis of the gyrB gene showed that these eight isolates could constitute a new species closely related to S. baltica. The Shewanella and A. salmonicida isolates produce off-odours and reduce trimethylamine oxide, indicating that they might contribute to the spoilage of the fish. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Population dynamics and antimicrobial susceptibility of Aeromonas spp. along a salinity gradient in an urban estuary in Northeastern Brazil.

    Science.gov (United States)

    Silva, Camila Magalhães; Evangelista-Barreto, Norma Suely; Vieira, Regine Helena Silva Dos Fernandes; Mendonça, Kamila Vieira; de Sousa, Oscarina Viana

    2014-12-15

    The main objective of this study was to quantify population and identify culturable species of Aeromonas in sediment and surface water collected along a salinity gradient in an urban estuary in Northeastern Brazil. Thirty sediment samples and 30 water samples were collected from 3 sampling locations (A, B and C) between October 2007 and April 2008. The Aeromonas count was 10-7050CFU/mL (A), 25-38,500CFU/mL (B) andAeromonas caviae, A. sobria, A. trota, A. salmonicida and A. allosaccharophila) were identified among 41 isolates. All strains were sensitive to chloramphenicol and ceftriaxone, whereas 33 (80, 4%) strains were resistant to at least 2 of the 9 antibiotics tested. Resistance to erythromycin was mostly plasmidial. In conclusion, due to pollution, the Cocó River is contaminated by pathogenic strains of Aeromonas spp. with a high incidence of antibacterial resistance, posing a serious risk to human health.

  12. Potential of the Melanophore Pigment Response for Detection of Bacterial Toxicity ▿

    OpenAIRE

    Dukovcic, Stephanie R.; Hutchison, Janine R.; Trempy, Janine E.

    2010-01-01

    Chromatophore cells have been investigated as potential biodetectors for function-based detection of chemically and biologically toxic substances. Oncorhynchus tshawytscha (chinook salmon) melanophores, a chromatophore cell type containing brown pigment, rapidly detect the salmonid pathogens Aeromonas salmonicida, Yersinia ruckeri, and Flavobacterium psychrophilum and the human pathogen Bacillus cereus.

  13. Potential of the melanophore pigment response for detection of bacterial toxicity.

    Science.gov (United States)

    Dukovcic, Stephanie R; Hutchison, Janine R; Trempy, Janine E

    2010-12-01

    Chromatophore cells have been investigated as potential biodetectors for function-based detection of chemically and biologically toxic substances. Oncorhynchus tshawytscha (chinook salmon) melanophores, a chromatophore cell type containing brown pigment, rapidly detect the salmonid pathogens Aeromonas salmonicida, Yersinia ruckeri, and Flavobacterium psychrophilum and the human pathogen Bacillus cereus.

  14. An investigation of the bactericidal activity of selected essential oils to Aeromonas spp.

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2015-01-01

    Full Text Available Diseases of fishes caused by Aeromonas spp. are common, have broad host ranges and may cause high mortality. Treatments of captive-reared populations using antimicrobials are limited with concerns for bacterial resistance development and environmental dissemination. This study was done to determine whether selected plant-derived essential oils were bactericidal to Aeromonas spp. Initially, twelve essential oils were evaluated using a disk diffusion assay to an isolate of A. salmonicida subsp. salmonicida, cause of fish furunculosis. The greatest zones of inhibition were obtained with oils of cinnamon Cinnamomum cassia, oregano Origanum vulgare, lemongrass Cymbopogon citratus and thyme Thymus vulgaris. Minimum bactericidal concentrations (MBC’s were determined for these four oils, Allimed® (garlic extract, Allium sativum and colloidal silver to sixty-nine isolates representing nine Aeromonas spp. The lowest mean MBCs (0.02–0.04% were obtained with three different sources of cinnamon oil. MBCs for three sources of oregano and lemongrass oils ranged from 0.14% to 0.30% and 0.10% to 0.65%, respectively, and for two thyme oils were 2.11% and 2.22%. The highest concentration (5% of Allimed® tested resulted in MBCs to twelve isolates. A concentration of silver greater than 15 mg/L would be required to determine MBCs for all but one isolate.

  15. Distinct Aeromonas Populations in Water Column and Associated with Copepods from Estuarine Environment (Seine, France

    Directory of Open Access Journals (Sweden)

    Gautier Chaix

    2017-07-01

    Full Text Available Aeromonas spp. are ubiquitous bacteria primarily recovered from aquatic ecosystems. They are found in fresh water as well as estuarine and marine waters, and in association with numerous autochthonous aquatic organisms in these environments. However, aeromonads are also etiologic agents of fish diseases and are now recognized as emerging pathogens in humans. The estuary is therefore a key environment, harboring autochthonous aeromonads, and aeromonads originating from humans and animals, mainly released by treated WWTP effluent or watershed run-off via tributaries. The present study compares the abundance and the diversity of Aeromonas populations. Over 2 years of monitoring (eight campaigns from February 2013 to November 2015, the occurrence of Aeromonas was investigated within the water column (water and fluid mud and in association with copepods. Moreover, the diversity of Aeromonas populations was ascertained by analyzing gyrB and radA sequences, and the antibiotic-resistance phenotypes were determined using the disk diffusion method. This study shows, for the first time, the presence of Aeromonas spp. in water (1.1 × 102 to 1.2 ± 0.3 × 103 CFU.100 mL-1, fluid mud (2.6 ± 2.6 × 102 to 9.8 ± 0.9 × 103 CFU.g-1 and in association with living copepods (1.9 ± 0.7 × 102 to >1.1 × 104 CFU.g-1 in the Seine estuary. Moreover, the diversity study, conducted on 36 strains isolated from the water column and 47 strains isolated from copepods, indicates distinct populations within these two compartments. Strains distributed in five clusters corresponding to A. bestiarum (n = 6; 5.45%, A. encheleia (n = 1; 0.91%, A. media (n = 22; 20.0%, A. rivipollensis (n = 34; 30.91% and A. salmonicida (n = 47; 42.73%. A. salmonicida is the most abundant species associated with Eurytemora affinis (n = 35; 74.47%. In contrast, A. salmonicida accounts for only 30.56% (n = 11 of isolates in the water column. This study shows the coexistence of distinct populations

  16. Distinct Aeromonas Populations in Water Column and Associated with Copepods from Estuarine Environment (Seine, France)

    Science.gov (United States)

    Chaix, Gautier; Roger, Frédéric; Berthe, Thierry; Lamy, Brigitte; Jumas-Bilak, Estelle; Lafite, Robert; Forget-Leray, Joëlle; Petit, Fabienne

    2017-01-01

    Aeromonas spp. are ubiquitous bacteria primarily recovered from aquatic ecosystems. They are found in fresh water as well as estuarine and marine waters, and in association with numerous autochthonous aquatic organisms in these environments. However, aeromonads are also etiologic agents of fish diseases and are now recognized as emerging pathogens in humans. The estuary is therefore a key environment, harboring autochthonous aeromonads, and aeromonads originating from humans and animals, mainly released by treated WWTP effluent or watershed run-off via tributaries. The present study compares the abundance and the diversity of Aeromonas populations. Over 2 years of monitoring (eight campaigns from February 2013 to November 2015), the occurrence of Aeromonas was investigated within the water column (water and fluid mud) and in association with copepods. Moreover, the diversity of Aeromonas populations was ascertained by analyzing gyrB and radA sequences, and the antibiotic-resistance phenotypes were determined using the disk diffusion method. This study shows, for the first time, the presence of Aeromonas spp. in water (1.1 × 102 to 1.2 ± 0.3 × 103 CFU.100 mL-1), fluid mud (2.6 ± 2.6 × 102 to 9.8 ± 0.9 × 103 CFU.g-1) and in association with living copepods (1.9 ± 0.7 × 102 to >1.1 × 104 CFU.g-1) in the Seine estuary. Moreover, the diversity study, conducted on 36 strains isolated from the water column and 47 strains isolated from copepods, indicates distinct populations within these two compartments. Strains distributed in five clusters corresponding to A. bestiarum (n = 6; 5.45%), A. encheleia (n = 1; 0.91%), A. media (n = 22; 20.0%), A. rivipollensis (n = 34; 30.91%) and A. salmonicida (n = 47; 42.73%). A. salmonicida is the most abundant species associated with Eurytemora affinis (n = 35; 74.47%). In contrast, A. salmonicida accounts for only 30.56% (n = 11) of isolates in the water column. This study shows the coexistence of distinct populations of

  17. Bacterial pathogens in rainbow trout, Oncorhynchus mykiss (Walbaum), reared at Danish freshwater farms

    DEFF Research Database (Denmark)

    Dalsgaard, Inger; Madsen, Lone

    2000-01-01

    During a 2-year period, bacterial fish pathogens were monitored on five rainbow trout, Oncorhynchus mykirs (Walbaum), freshwater farms in Denmark. A total of 1206 fish were examined and 361 bacterial isolates were identified phenotypically. Enteric redmouth disease, furunculosis and rainbow trout....... psychrophilum isolates showed resistance to oxolinic acid and oxytetracycline. No antibiotic resistant isolates were found among Y. ruckeri and A. salmonicida....... fry syndrome/coldwater disease were recorded. Infections caused by Flavobacterium psychrophilum occurred most frequently, but only one outbreak of enteric redmouth disease caused by Yersinia ruckeri serotype O1 and one of furunculosis caused by Aeromonas salmonicida were recorded during the monitoring...

  18. Phylogenetic diversity of Aeromonas from "alheira," a traditional Portuguese meat product.

    Science.gov (United States)

    Fontes, M C; Martins, C; Martínez-Murcia, A J; Saavedra, M J

    2012-08-01

    "Alheira" is a traditional smoked meat sausage produced in the north of Portugal, representing an important economic resource for the region. This meat product has been subjected to research studies with the aim of detecting the presence of common foodborne pathogens, but, to our knowledge, isolation of emerging foodborne Aeromonas from alheira has never been previously described. Present work attempts to evaluate the Aeromonas species diversity of 84 isolates of Aeromonas spp. collected from 32 alheira samples. All presumptive Aeromonas isolates were subjected to genotyping by enterobacterial repetitive intergenic consensus-polymerase chain reaction analysis. The isolates presenting a different pattern were subjected to gyrB gene sequencing for species classification, and the species A. hydrophila, A. salmonicida, A. caviae, A. media, and A. allosaccharophila were identified. The Aeromonas species diversity found has not been previously described in any other meat product evaluated in previous studies. It is also important to highlight the presence of A. hydrophila and A. caviae because they were previously associated with illness in humans, including gastroenteritis.

  19. Occurrence of Flavobacterium psychrophilum in fish-farming environments

    DEFF Research Database (Denmark)

    Madetoja, J.; Dalsgaard, Inger; Wiklund, T.

    2002-01-01

    . Isolates were biochemically homogenous, excluding the capability to degrade elastin. Five different agglutination patterns with different antisera against F. psychrophilum were found among the isolates studied. Although several different ribopatterns were found (ClaI: 12 ribopatterns and HaeIII: 9...

  20. Diversity of Flavobacterium psychrophilum and the potential use of its phages for protection against bacterial cold water disease in salmonids

    DEFF Research Database (Denmark)

    Castillo, D.; Higuera, G.; Villa, M.

    2012-01-01

    Flavobacterium psychrophilum causes rainbow trout fry syndrome (RTFS) and cold water disease (CWD) in salmonid aquaculture. We report characterization of F. psychrophilum strains and their bacteriophages isolated in Chilean salmonid aquaculture. Results suggest that under laboratory conditions ph...

  1. Antimicrobial resistance patterns in Danish isolates of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Bruun, Morten Sichlau; Schmidt, A.S.; Madsen, Lone

    2000-01-01

    were tested and the resulting antibiograms were used to predict the theoretical therapeutic efficacy and to evaluate if resistance had changed as a course of time. Antimicrobial agents included in this investigation were oxolinic acid (OXA), amoxicillin (AMX), potentiated sulfadiazine, oxytetracycline......The resistance pattern of Flavobacterium psychrophilum to the antimicrobial agents used in fish farming in Denmark was assessed in vitro using an agar dilution method. After identification of 387 isolates from clinical outbreaks of rainbow trout fry syndrome (RTFS) and the environment, the isolates...... (OTC) and florfenicol (FLO). We found that F. psychrophilum isolates divided in susceptible and resistant clusters reflecting the reduced efficacy in practice when using OTC and AMX. The most recent isolates were less susceptible to AMX and OXA, whereas resistance to OTC seemed stable over the last 5...

  2. Combining Suppression Subtractive Hybridization and Microarrays To Map the Intraspecies Phylogeny of Flavobacterium psychrophilum

    OpenAIRE

    Soule, Marilyn; Cain, Kenneth; Lafrentz, Stacey; Douglas R. Call

    2005-01-01

    Reciprocal subtractive libraries were prepared for two strains of Flavobacterium psychrophilum, one virulent and the other avirulent in a trout challenge model. Unique clones were sequenced and their distribution assessed among 34 strains. The analysis showed that F. psychrophilum is composed of two genetic lineages, possibly reflecting host specificity.

  3. Genomic diversity of bacteriophages infecting the fish pathogen Flavobacterium psychrophilum.

    Science.gov (United States)

    Castillo, Daniel; Middelboe, Mathias

    2016-12-01

    Bacteriophages infecting the fish pathogen Flavobacterium psychrophilum can potentially be used to prevent and control outbreaks of this bacterium in salmonid aquaculture. However, the application of bacteriophages in disease control requires detailed knowledge on their genetic composition. To explore the diversity of F. pyschrophilum bacteriophages, we have analyzed the complete genome sequences of 17 phages isolated from two distant geographic areas (Denmark and Chile), including the previously characterized temperate bacteriophage 6H. Phage genome size ranged from 39 302 to 89 010 bp with a G+C content of 27%-32%. None of the bacteriophages isolated in Denmark contained genes associated with lysogeny, whereas the Chilean isolates were all putative temperate phages and similar to bacteriophage 6H. Comparative genome analysis showed that phages grouped in three different genetic clusters based on genetic composition and gene content, indicating a limited genetic diversity of F. psychrophilum-specific bacteriophages. However, amino acid sequence dissimilarity (25%) was found in putative structural proteins, which could be related to the host specificity determinants. This study represents the first analysis of genomic diversity and composition among bacteriophages infecting the fish pathogen F. psychrophilum and discusses the implications for the application of phages in disease control. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Detection of Flavobacterium psychrophilum from fish tissue and water samples by PCR amplification

    DEFF Research Database (Denmark)

    Wiklund, T.; Madsen, Lone; Bruun, Morten Sichlau

    2000-01-01

    Rainbow trout fry syndrome and cold-water disease, caused by Flavobacterium psychrophilum, are important diseases in farmed salmonids. Some of the presently available techniques for the detection of Fl. psychrophilum are either time consuming or lack sufficient sensitivity. In the present...... investigation, the possible detection of Fl. psychrophilum from fish tissue and water samples was examined using nested PCR with DNA probes against a sequence of the 16S rRNA genes. The DNA was extracted using Chelex(R) 100 chelating resin. The primers, which were tested against strains isolated from diseased...... to be more sensitive than agar cultivation of tissue samples from the brain of rainbow trout injected with Fl. psychrophilum. In non-sterile fresh water seeded with Fl. psychrophilum the detection limit of the PCR- assay was 1.7 cfu in the PCR tube, corresponding to 110 cfu ml(-1) water. The PCR...

  5. Growth inhibition of Aeromonas salmonicida and Yersinia ruckeri by disinfectants containing peracetic acid

    DEFF Research Database (Denmark)

    Meinelt, Thomas; Phan, T.; Behrens, S.;

    2015-01-01

    Peracetic acid (PAA) is a therapeutic agent used for disinfection in aquaculture, but it must be investigated thoroughly in order to mitigate diseases without harming the fish. Successful disinfectants (like PAA) should not leave dangerous residues in the environment in order to successfully...

  6. Growth inhibition of Aeromonas salmonicida and Yersinia ruckeri by disinfectants containing peracetic acid

    Science.gov (United States)

    Peracetic acid (PAA) is an agent used for disinfection in aquaculture. PAA contributes to sustainable aquaculture, because it releases no harmful residue in the environment. However, there is lack of guideline about the effective application of different PAA products against various pathogens in p...

  7. Phenotypic and Genetic Diversity of Aeromonas Species Isolated from Fresh Water Lakes in Malaysia.

    Science.gov (United States)

    Khor, Wei Ching; Puah, Suat Moi; Tan, Jin Ai Mary Anne; Puthucheary, S D; Chua, Kek Heng

    2015-01-01

    Gram-negative bacilli of the genus Aeromonas are primarily inhabitants of the aquatic environment. Humans acquire this organism from a wide range of food and water sources as well as during aquatic recreational activities. In the present study, the diversity and distribution of Aeromonas species from freshwater lakes in Malaysia was investigated using glycerophospholipid-cholesterol acyltransferase (GCAT) and RNA polymerase sigma-factor (rpoD) genes for speciation. A total of 122 possible Aeromonas strains were isolated and confirmed to genus level using the API20E system. The clonality of the isolates was investigated using ERIC-PCR and 20 duplicate isolates were excluded from the study. The specific GCAT-PCR identified all isolates as belonging to the genus Aeromonas, in agreement with the biochemical identification. A phylogenetic tree was constructed using the rpoD gene sequence and all 102 isolates were identified as: A. veronii 43%, A. jandaei 37%, A. hydrophila 6%, A. caviae 4%, A. salmonicida 2%, A. media 2%, A. allosaccharophila 1%, A. dhakensis 1% and Aeromonas spp. 4%. Twelve virulence genes were present in the following proportions--exu 96%, ser 93%, aer 87%, fla 83%, enolase 70%, ela 62%, act 54%, aexT 33%, lip 16%, dam 16%, alt 8% and ast 4%, and at least 2 of these genes were present in all 102 strains. The ascV, aexU and hlyA genes were not detected among the isolates. A. hydrophila was the main species containing virulence genes alt and ast either present alone or in combination. It is possible that different mechanisms may be used by each genospecies to demonstrate virulence. In summary, with the use of GCAT and rpoD genes, unambiguous identification of Aeromonas species is possible and provides valuable data on the phylogenetic diversity of the organism.

  8. Phenotypic and Genetic Diversity of Aeromonas Species Isolated from Fresh Water Lakes in Malaysia.

    Directory of Open Access Journals (Sweden)

    Wei Ching Khor

    Full Text Available Gram-negative bacilli of the genus Aeromonas are primarily inhabitants of the aquatic environment. Humans acquire this organism from a wide range of food and water sources as well as during aquatic recreational activities. In the present study, the diversity and distribution of Aeromonas species from freshwater lakes in Malaysia was investigated using glycerophospholipid-cholesterol acyltransferase (GCAT and RNA polymerase sigma-factor (rpoD genes for speciation. A total of 122 possible Aeromonas strains were isolated and confirmed to genus level using the API20E system. The clonality of the isolates was investigated using ERIC-PCR and 20 duplicate isolates were excluded from the study. The specific GCAT-PCR identified all isolates as belonging to the genus Aeromonas, in agreement with the biochemical identification. A phylogenetic tree was constructed using the rpoD gene sequence and all 102 isolates were identified as: A. veronii 43%, A. jandaei 37%, A. hydrophila 6%, A. caviae 4%, A. salmonicida 2%, A. media 2%, A. allosaccharophila 1%, A. dhakensis 1% and Aeromonas spp. 4%. Twelve virulence genes were present in the following proportions--exu 96%, ser 93%, aer 87%, fla 83%, enolase 70%, ela 62%, act 54%, aexT 33%, lip 16%, dam 16%, alt 8% and ast 4%, and at least 2 of these genes were present in all 102 strains. The ascV, aexU and hlyA genes were not detected among the isolates. A. hydrophila was the main species containing virulence genes alt and ast either present alone or in combination. It is possible that different mechanisms may be used by each genospecies to demonstrate virulence. In summary, with the use of GCAT and rpoD genes, unambiguous identification of Aeromonas species is possible and provides valuable data on the phylogenetic diversity of the organism.

  9. CHLORINE DISINFECTION OF AEROMONAS

    Science.gov (United States)

    The bacterial genus Aeromonas is currently listed on the USEPA's Candidate Contaminant List (CCL). Resistance to chemical disinfection is an essential aspect regarding all microbial groups listed on the CCL. This study was designed to determine the inactivation kinetics of Aeromo...

  10. Stable Transfection of the Diplomonad Parasite Spironucleus salmonicida

    OpenAIRE

    Jerlström-Hultqvist, Jon; Einarsson, Elin; Staffan G Svärd

    2012-01-01

    Eukaryotic microbes are highly diverse, and many lineages remain poorly studied. One such lineage, the diplomonads, a group of binucleate heterotrophic flagellates, has been studied mainly due to the impact of Giardia intestinalis, an intestinal, diarrhea-causing parasite in humans and animals. Here we describe the development of a stable transfection system for use in Spironucleus salmonicida, a diplomonad that causes systemic spironucleosis in salmonid fish. We designed vectors in cassette ...

  11. Stable Transfection of the Diplomonad Parasite Spironucleus salmonicida

    Science.gov (United States)

    Einarsson, Elin; Svärd, Staffan G.

    2012-01-01

    Eukaryotic microbes are highly diverse, and many lineages remain poorly studied. One such lineage, the diplomonads, a group of binucleate heterotrophic flagellates, has been studied mainly due to the impact of Giardia intestinalis, an intestinal, diarrhea-causing parasite in humans and animals. Here we describe the development of a stable transfection system for use in Spironucleus salmonicida, a diplomonad that causes systemic spironucleosis in salmonid fish. We designed vectors in cassette format carrying epitope tags for localization (3×HA [where HA is hemagglutinin], 2× Escherichia coli OmpF linker and mouse langerin fusion sequence [2×OLLAS], 3×MYC) and purification of proteins (2× Strep-Tag II–FLAG tandem-affinity purification tag or streptavidin binding peptide–glutathione S-transferase [SBP-GST]) under the control of native or constitutive promoters. Three selectable gene markers, puromycin acetyltransferase (pac), blasticidin S-deaminase (bsr), and neomycin phosphotransferase (nptII), were successfully applied for the generation of stable transfectants. Site-specific integration on the S. salmonicida chromosome was shown to be possible using the bsr resistance gene. We epitope tagged six proteins and confirmed their expression by Western blotting. Next, we demonstrated the utility of these vectors by recording the subcellular localizations of the six proteins by laser scanning confocal microscopy. Finally, we described the creation of an S. salmonicida double transfectant suitable for colocalization studies. The transfection system described herein and the imminent completion of the S. salmonicida genome will make it possible to use comparative genomics as an investigative tool to explore specific, as well as general, diplomonad traits, benefiting research on both Giardia and Spironucleus. PMID:22983987

  12. CARACTERIZACION DE CEPAS CHILENAS DE FLAVOBACTERIUM PSYCHROPHILUM Y SENSIBILIDAD A ANTIMICROBIANOS.

    OpenAIRE

    RIOFRIO MONTERO, ANDRES PATRICIO

    2002-01-01

    Flavobacterium psychrophilum (Bernardet y col., 1996), anteriormente denominada Flexibacter psychrophilus (Bernardet y Grimont, 1989) y Cytophaga psychrophila (Baudin-Laurencin y col., 1989), es un importante patógeno de peces de agua dulce, ampliamente d 146p.

  13. In vivo adherence of Flavobacterium psychrophilum to mucosal external surfaces of rainbow trout (Oncorhynchus mykiss) fry

    DEFF Research Database (Denmark)

    Papadopoulou, A.; Dalsgaard, Inger; Lindén, A.

    2017-01-01

    and kidney were taken and inoculated onto TYES agar plates. Colony phenotypes of F. psychrophilum were identified and number of colonies counted. The results showed that cells of both phenotypes initially (0 h) adhered to all mucosal surfaces, but only the rough cells were still present on tissues 1 h post....... psychrophilum to mucosal tissues of rainbow trout fry and to test the skin mucus as a nutrient for the growth of F. psychrophilum. Fish were immersed in water containing 106  CFU  mL-1 F. psychrophilum for each colony phenotype. Mucosal tissue samples from fins, gills, skin and eyes, and swab samples from spleen...

  14. Production of viable cultures of Flavobacterium psychrophilum: approach and control.

    Science.gov (United States)

    Michel, C; Antonio, D; Hedrick, R P

    1999-06-01

    Although the fish pathogen Flavobacterium psychrophilum is a major source of concern in salmonid hatcheries, few studies have been conducted on its pathogenicity. Difficulties are often experienced when trying to control or quantify standard procedures for in vitro culture of the bacterium. Plate enumeration and counting chamber enumeration combined with epifluorescent microscopy with fluorescent dyes determined that no more than 25% of the bacterial cells present in the cultures were able to produce colonies on agar media. This was strongly dependent upon different medium components. Tryptone-enriched Anacker and Ordal medium proved more suitable than tryptone-yeast extract-salts with skimmed milk. Adding horse serum and trace elements in controlled proportions offered the most reproducible results. Viable but nonculturable forms were apparently not responsible for the difficulties in production of F. psychrophilum, but the cells were highly susceptible to osmotic conditions. Improvements in the media and careful handling of the bacteria in isotonic suspension media resulted in predictable production of viable bacteria and allowed an absorbance/colony-forming-units relation curve to be established.

  15. Comparative Genome Analysis Provides Insights into the Pathogenicity of Flavobacterium psychrophilum

    Science.gov (United States)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Dalsgaard, Inger; Madsen, Lone; Espejo, Romilio

    2016-01-01

    Flavobacterium psychrophilum is a fish pathogen in salmonid aquaculture worldwide that causes cold water disease (CWD) and rainbow trout fry syndrome (RTFS). Comparative genome analyses of 11 F. psychrophilum isolates representing temporally and geographically distant populations were used to describe the F. psychrophilum pan-genome and to examine virulence factors, prophages, CRISPR arrays, and genomic islands present in the genomes. Analysis of the genomic DNA sequences were complemented with selected phenotypic characteristics of the strains. The pan genome analysis showed that F. psychrophilum could hold at least 3373 genes, while the core genome contained 1743 genes. On average, 67 new genes were detected for every new genome added to the analysis, indicating that F. psychrophilum possesses an open pan genome. The putative virulence factors were equally distributed among isolates, independent of geographic location, year of isolation and source of isolates. Only one prophage-related sequence was found which corresponded to the previously described prophage 6H, and appeared in 5 out of 11 isolates. CRISPR array analysis revealed two different loci with dissimilar spacer content, which only matched one sequence in the database, the temperate bacteriophage 6H. Genomic Islands (GIs) were identified in F. psychrophilum isolates 950106-1/1 and CSF 259–93, associated with toxins and antibiotic resistance. Finally, phenotypic characterization revealed a high degree of similarity among the strains with respect to biofilm formation and secretion of extracellular enzymes. Global scale dispersion of virulence factors in the genomes and the abilities for biofilm formation, hemolytic activity and secretion of extracellular enzymes among the strains suggested that F. psychrophilum isolates have a similar mode of action on adhesion, colonization and destruction of fish tissues across large spatial and temporal scales of occurrence. Overall, the genomic characterization and

  16. Characterization of Aeromonas strains isolated from Indian foods using rpoD gene sequencing and whole cell protein analysis.

    Science.gov (United States)

    Nagar, Vandan; Shashidhar, Ravindranath; Bandekar, Jayant R

    2013-04-01

    Aeromonas are responsible for causing gastroenteritis and extra-intestinal infections in humans. Twenty-two Aeromonas strains isolated from different food sources were re-identified up to species level using rpoD gene sequence analysis. Biochemical tests and 16S rRNA gene sequencing were insufficient to identify Aeromonas till species level. However, incorporation of additional biochemical tests lead to correct identification of 95.5 % strains up to species level. The 16S rRNA gene sequencing was useful to identify Aeromonas isolates at the genus level only. Sequences of the rpoD gene showed greater discriminatory power than 16S rRNA gene and provided conclusive discrimination of the strains for which the phenotypic species identification was uncertain. All these 22 strains were accurately identified up to species level by rpoD gene as A. salmonicida (6), A. veronii bv. veronii (4), A. caviae (3), A. hydrophila (2), A. veronii bv. sobria (2), A. jandaei (1), A. trota (1), A. sobria (1), A. allosaccharophila (1) and A. bivalvium (1). All these strains were also characterized using whole cell protein (WCP) analysis by gradient SDS-PAGE and showed different whole cell protein (WCP) profile [22-28 polypeptide bands (~10 to >97 kDa)], indicating high genetic diversity. The present work emphasizes the use of molecular methods such as rpoD gene sequencing along with comprehensive biochemical tests for the rapid and accurate identification of Aeromonas isolates till species level. The WCP profile can be subsequently used to characterize Aeromonas isolates below species level.

  17. Aeromonas spp.: an emerging pathogen?

    Directory of Open Access Journals (Sweden)

    Andrea Bartolini

    2015-12-01

    Full Text Available The aim of this study is to identify and monitor the presence of Aeromonas spp. strains in stool cultures. We analyzed 5564 stool cultures from September 2012 to August 2013. Sixty-three patients were positive for Aeromonas spp. The most frequent symptoms were: diarrhea (46.0% and abdominal pain (12.7%. Pediatric subjects were 28. Samples’ microscopic examination showed leukocytes in 38.1% of cases. It is still controversial whether Aeromonas are responsible for human gastroenteritis, but their presence in faecies of symptomatic patients supports their etiologic role. We propose search for toxins by polymerase chain reaction to identify strains that require an antibiotic therapy.

  18. Genomic structure of bacteriophage 6H and its distribution as prophage in Flavobacterium psychrophilum strains

    DEFF Research Database (Denmark)

    Castillo Bermúdez, Daniel Elías; Espejo, Romilio; Middelboe, Mathias

    2014-01-01

    Flavobacterium psychrophilum is currently one of the most devastating fish pathogens worldwide causing considerable economic losses in salmonid aquaculture. Recently, attention has been drawn to the use of phages for controlling F. psychrophilum, and phages infecting the pathogen have been isolat...

  19. Comparative Genome Analysis Provides Insights into the Pathogenicity of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Dalsgaard, Inger;

    2016-01-01

    . psychrophilum could hold at least 3373 genes, while the core genome contained 1743 genes. On average, 67 new genes were detected for every new genome added to the analysis, indicating that F. psychrophilum possesses an open pan genome. The putative virulence factors were equally distributed among isolates......, independent of geographic location, year of isolation and source of isolates. Only one prophage-related sequence was found which corresponded to the previously described prophage 6H, and appeared in 5 out of 11 isolates. CRISPR array analysis revealed two different loci with dissimilar spacer content, which...... to describe the F. psychrophilum pan-genome and to examine virulence factors, prophages, CRISPR arrays, and genomic islands present in the genomes. Analysis of the genomic DNA sequences were complemented with selected phenotypic characteristics of the strains. The pan genome analysis showed that F...

  20. Phage-Host Interactions in Flavobacterium psychrophilum and the Potential for Phage Therapy in Aquaculture

    DEFF Research Database (Denmark)

    Christiansen, Rói Hammershaimb

    , the increasing problem with antibiotic resistance has led to increased attention to the use of phages for controlling F. psychrophilum infections in aquaculture. In a synopsis and four scientific papers, this PhD project studies the potential and optimizes the use of phage therapy for treatment and prevention...... of F. psychrophilum infections in rainbow trout fry. In the first paper, studies of the controlling effect of different phages infecting F. psychrophilum in liquid cultures showed that a high initial phage concentration was crucial for fast and effective bacterial lysis in the cultures and sensitive...... cells could be maintained at a low level throughout the rest of the experiment. Surprisingly, no difference was observed between infection with single phages or phage cocktails. At the end of incubation phage-sensitive strains dominated in the cultures with low initial phage concentrations and phage...

  1. [Detection of the first QnrS gene positivity in aquatic Aeromonas spp. isolates in Turkey].

    Science.gov (United States)

    Onuk, Ertan Emek; Tanrıverdi Çaycı, Yeliz; Çoban, Ahmet Yılmaz; Çiftci, Alper; Balta, Fikri; Didinen, Behire Işıl; Pekmezci, Gökmen Zafer; Altun, Soner; Söğüt Ünlü, Mehtap; Deveci, Aydın

    2015-01-01

    Aeromonas spp. are oxidase positive, gram-negative, facultative anaerobic bacilli that are widely distributed in aquatic environments. A.hydrophila, A.sobria and A.bestiarum may cause severe infections in both human and cold-blooded animals. Environmental persistance of quinolones that are widely used in both human and veterinary medicine plays an important role in the selection of resistant mutants. Plasmid-mediated resistance is one of the main mechanisms involved in quinolone resistance, and qnr, qepA, aac(6')-Ib-cr, oqxAB genes are identified as resistance determinants. Determination of various types of qnr gene in different bacteria mainly in Enterobacteriaceae, suggests that they are widely distributed in nature. Recently, plasmid-mediated quinolone resistance was defined among Aeromonas species isolated from water. The aim of this study was to investigate the presence of qnr genes among aquatic Aeromonas spp. in Turkey. A total of 45 Aeromonas strains isolated from water and fishes collected from three different geographical regions (Aegean, Mediterranean and Blacksea) in Turkey, were included in the study. The isolates were identified at species level by the use of 16S rDNA-RFLP (Restriction fragment length polymorphism) analysis and multiplex polymerase chain reaction (M-PCR). Among the isolates, 20 were identified as A.sobria, 10 as A.hydrophila, nine as A.salmonicida, four as A.bestiarum and two as A.veronii. The plasmid-mediated quinolone resistance determinants, qnrA, qnrB, qnrC and qnrS genes, were investigated by M-PCR, and sequence analysis was performed for nine qnr-positive isolates. According to the sequence analysis of the genes, qnr genes were characterized in six A.sobria, in two A.bestiarum and in one A.hydrophila isolate (9/45; 20%). When the sequence was compared with GenBank database, this gene was found as qnrS2. All qnrS-positive Aeromonas spp. isolates were ciprofloxacin-susceptible, while five of them were resistant to nalidixic acid

  2. Evidence of increased antibiotic resistance in phylogenetically-diverse Aeromonas isolates from semi-intensive fish ponds treated with antibiotics

    Directory of Open Access Journals (Sweden)

    Hemant J Patil

    2016-11-01

    identified, including an A. salmonicida cluster that harbored all characterized fish skin ulcer samples. Subsequent to stocking diversity was much lower and most water column isolates in both facilities segregated into an A. veronii-associated cluster. This study demonstrated a strong correlation between aquaculture, Aeromonas diversity and antibiotic resistance. It provides strong evidence for linkage between prophylactic and systemic use of antibiotics in aquaculture and the propagation of antibiotic resistance.

  3. Variable Number of Tandem Repeats (VNTR) analysis of Flavobacterium psychrophilum from salmonids in Chile and Norway

    DEFF Research Database (Denmark)

    Apablaza, Patricia; Brevik, Oyvind J.; Mjos, Svein

    2015-01-01

    isolates of this bacterium could play an important role in the development of good management strategies. The aim of this study was to identify genetic markers for discrimination between isolates. A selection of eight VNTRs from 53 F. psychrophilum isolates from Norway, Chile, Denmark and Scotland were...... compared to those from Norway, which suggests a more homogenous reservoir in Norway. Transgenerational transmission of F. psychrophilum from other countries, exporting salmon embryos to Chile, may explain the differences in diversity. The same transmission mechanisms could also explain the wide...

  4. Chlorinated and ultraviolet radiation -treated reclaimed irrigation water is the source of Aeromonas found in vegetables used for human consumption.

    Science.gov (United States)

    Latif-Eugenín, Fadua; Beaz-Hidalgo, Roxana; Silvera-Simón, Carolina; Fernandez-Cassi, Xavi; Figueras, María J

    2017-04-01

    Wastewater is increasingly being recognized as a key water resource, and reclaimed water (or treated wastewater) is used for irrigating vegetables destined for human consumption. The aim of the present study was to determine the diversity and prevalence of Aeromonas spp. both in reclaimed water used for irrigation and in the three types of vegetables irrigated with that water. Seven of the 11 (63.6%) samples of reclaimed water and all samples of vegetables were positive for the presence of Aeromonas. A total of 216 Aeromonas isolates were genotyped and corresponded to 132 different strains that after identification by sequencing the rpoD gene belonged to 10 different species. The prevalence of the species varied depending on the type of sample. In the secondary treated reclaimed water A. caviae and A. media dominated (91.4%) while A. salmonicida, A. media, A. allosaccharophila and A. popoffii represented 74.0% of the strains in the irrigation water. In vegetables, A. caviae (75.0%) was the most common species, among which a strain isolated from lettuce had the same genotype (ERIC pattern) as a strain recovered from the irrigation water. Furthermore, the same genotype of the species A. sanarellii was recovered from parsley and tomatoes demonstrating that irrigation water was the source of contamination and confirming the risk for public health. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Radiological examination of the spinal column in farmed rainbow trout Oncorhynchus mykiss (Walbaum): experiments with Flavobacterium psychrophilum and oxytetracycline

    DEFF Research Database (Denmark)

    Madsen, Lone; Arnbjerg, J.; Dalsgaard, Inger

    2001-01-01

    Flavobacterium psychrophilum and oxytetracycline have both been associated with spinal deformities in salmonids. Experiments were carried out to investigate whether infection with F, psychrophilum or medication with oxytetracycline (OTC) at the fry stage would result in an increased occurrence...... of vertebral column deformities in rainbow trout, Oncorhynchus mykiss (Walbaum). Fish were on-grown for 9 months and examined by radiology at the end of the experiments. There was a relationship between infection by F. psychrophilum and deformities of the spinel column, if fish with more than 10 affected...

  6. Effect of Bacteriophages on the Growth of Flavobacterium psychrophilum and Development of Phage-Resistant Strains

    DEFF Research Database (Denmark)

    Christiansen, Rói Hammershaimb; Madsen, Lone; Dalsgaard, Inger;

    2016-01-01

    The controlling effect of single and multiple phages on the density of Flavobacterium psychrophilum at different initial multiplicity of infection (MOI) was assessed in batch cultures to explore the potential for phage-based treatment of this important fish pathogen. A high initial phage concentr...

  7. Effect of Hydrogen Peroxide on Immersion Challenge of Rainbow Trout Fry with Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi; Madsen, Lone; Dalsgaard, Inger

    2013-01-01

    and produce high levels of mortality attempts to establish a reproducible immersion model have been less successful. Various concentrations of hydrogen peroxide (H2O2) were evaluated before being used as a pre-treatment stressor prior to immersion exposure to F. psychrophilum. H2O2 accelerated the onset...

  8. Phenotypic and genotypic characterization of Flavobacterium psychrophilum from Finnish fish farms

    DEFF Research Database (Denmark)

    Madetoja, J.; Hanninen, M.L.; Hirvela-Koski, V.;

    2001-01-01

    characteristics were observed. Seven different antigenic patterns among Finnish isolates were detected and the results suggest a new serotype of F. psychrophilum. Using CIA HaeIII and PvuII restriction enzymes in ribotyping analyses 13 different genotypes were demonstrated and a possible relationship between...

  9. Multilocus Sequence Typing Identifies Epidemic Clones of Flavobacterium psychrophilum in Nordic Countries

    DEFF Research Database (Denmark)

    Nilsen, Hanne; Sundell, Krister; Duchaud, Eric

    2014-01-01

    , Norway, and Sweden. Multilocus sequence typing of 560 geographically and temporally disparate F. psychrophilum isolates collected from various sources between 1983 and 2012 revealed 81 different sequence types (STs) belonging to 12 clonal complexes (CCs) and 30 singleton STs. The largest CC, CC-ST10...

  10. Ribosomal multi-operon diversity: an original perspective on the genus Aeromonas.

    Directory of Open Access Journals (Sweden)

    Frédéric Roger

    Full Text Available 16S rRNA gene (rrs is considered of low taxonomic interest in the genus Aeromonas. Here, 195 Aeromonas strains belonging to populations structured by multilocus phylogeny were studied using an original approach that considered Ribosomal Multi-Operon Diversity. This approach associated pulsed-field gel electrophoresis (PFGE to assess rrn operon number and distribution across the chromosome and PCR-temporal temperature gel electrophoresis (TTGE to assess rrs V3 region heterogeneity. Aeromonads harbored 8 to 11 rrn operons, 10 operons being observed in more than 92% of the strains. Intraspecific variability was low or nul except for A. salmonicida and A. aquariorum suggesting that large chromosomic rearrangements might occur in these two species while being extremely rarely encountered in the evolution of other taxa. rrn operon number at 8 as well as PFGE patterns were shown valuable for taxonomic purpose allowing resolution of species complexes. PCR-TTGE revealed a high rate of strains (41.5% displaying intragenomic rrs heterogeneity. Strains isolated from human samples more frequently displayed intragenomic heterogeneity than strains recovered from non-human and environmental specimens. Intraspecific variability ranged from 0 to 76.5% of the strains. The observation of species-specific TTGE bands, the recovery of identical V3 regions in different species and the variability of intragenomic heterogeneity (1-13 divergent nucleotides supported the occurrence of mutations and horizontal transfer in aeromonad rrs evolution. Altogether, the presence of a high number of rrn operon, the high proportion of strains harboring divergent rrs V3 region and the previously demonstrated high level of genetic diversity argued in favor of highly adaptative capabilities of aeromonads. Outstanding features observed for A. caviae supported the ongoing process of adaptation to a specialized niche represented by the gut, previously hypothesized. 16S rRNA gene is an

  11. Evolution of interleukin-1 receptor-like 1 and its role in rainbow trout (Oncorhynchus mykiss) resistance to Flavobacterium psychrophilum

    Science.gov (United States)

    Rainbow trout exhibit extensive phenotypic variation in innate disease resistance and we have divergently selected lines with either increased or reduced survival following exposure to the gram-negative bacterium, Flavobacterium psychrophilum (Fp). Following five generations of selection, gene expr...

  12. Transcription Factor T-Bet in Atlantic Salmon: Characterization and Gene Expression in Mucosal Tissues during Aeromonas Salmonicida Infection

    National Research Council Canada - National Science Library

    Kumari, Jaya; Zhang, Zuobing; Swain, Trilochan; Chi, Heng; Niu, Cuijuan; Bøgwald, Jarl; Dalmo, Roy Ambli

    2015-01-01

    The T-box transcription factor T-bet is expressed in a number of hematopoietic cell types in mammals and plays an essential role in the lineage determination of Th1 T-helper cells and is considered...

  13. Identification of hydroxy fatty acids in Aeromonas hydrophila, Aeromonas sobria, and Aeromonas caviae.

    OpenAIRE

    1985-01-01

    Gas-liquid chromatographic analysis of fatty acid methyl esters obtained from clinical isolates of Aeromonas hydrophila, A. sobria, and A. caviae revealed the presence of two hydroxy fatty acid species, 3-OH 12:0 and 3-OH 14:0.

  14. Relation of chironomids with Aeromonas species

    Directory of Open Access Journals (Sweden)

    Sivan eLaviad

    2016-05-01

    Full Text Available Chironomids (Diptera: Chironomidae, also known as non-biting midges, are one of the most abundant groups of insects in aquatic habitats. They undergo a complete metamorphosis of four life stages of which three are aquatic (egg, larva, pupa, and the adult emerges into the air. Chironomids serve as a natural reservoir of Aeromonas and Vibrio cholerae species. Here we review existing knowledge about the mutual relations between Aeromonas species and chironomids. Using 454-pyrosequencing of the 16S rRNA gene, we found that the prevalence of Aeromonas species in the insects’ egg masses and larvae was 1.6% and 3.3% of the insects’ endogenous microbiota, respectively. Aeromonas abundance per egg mass remained stable during a six-month period of bacterial monitoring. Different Aeromonas species were isolated and some demonstrated the ability to degrade the insect’s egg masses and to prevent eggs hatching. Chitinase was identified as the enzyme responsible for the egg mass degradation. Different Aeromonas species isolated from chironomids demonstrated the potential to protect their host from toxic metals. Aeromonas is a causative agent of fish infections. Fish are frequently recorded as feeding on chironomids. Thus, fish might be infected with Aeromonas species via chironomid consumption. Aeromonas strains are also responsible for causing gastroenteritis and wound infections in humans. Different virulence genes were identified in Aeromonas species isolated from chironomids. Chironomids may infest drinking water reservoirs, hence be the source of pathogenic Aeromonas strains in drinking water. Chironomids and Aeromonas species have a complicated mutual relationship.

  15. Genomic Characterization of Flavobacterium psychrophilum Serotypes and Development of a Multiplex PCR-Based Serotyping Scheme

    Directory of Open Access Journals (Sweden)

    Tatiana Rochat

    2017-09-01

    Full Text Available Flavobacterium psychrophilum is a devastating bacterial pathogen of salmonids reared in freshwater worldwide. So far, serological diversity between isolates has been described but the underlying molecular factors remain unknown. By combining complete genome sequence analysis and the serotyping method proposed by Lorenzen and Olesen (1997 for a set of 34 strains, we identified key molecular determinants of the serotypes. This knowledge allowed us to develop a robust multiplex PCR-based serotyping scheme, which was applied to 244 bacterial isolates. The results revealed a striking association between PCR-serotype and fish host species and illustrate the use of this approach as a simple and cost-effective method for the determination of F. psychrophilum serogroups. PCR-based serotyping could be a useful tool in a range of applications such as disease surveillance, selection of salmonids for bacterial coldwater disease resistance and future vaccine formulation.

  16. Characterization of integrons and tetracycline resistance determinants in Aeromonas spp. isolated from South African aquaculture systems.

    Science.gov (United States)

    Jacobs, Liezl; Chenia, Hafizah Y

    2007-03-20

    An increasing incidence of multidrug resistance amongst Aeromonas spp. isolates, which are both fish pathogens and emerging opportunistic human pathogens, has been observed worldwide. This can be attributed to the horizontal transfer of mobile genetic elements, viz.: plasmids and class 1 integrons. The antimicrobial susceptibilities of 37 Aeromonas spp. isolates, from tilapia, trout and koi aquaculture systems, were determined by disc-diffusion testing. The plasmid content of each isolate was examined using the alkaline lysis protocol. Tet determinant type was determined by amplification using two degenerate primer sets and subsequent HaeIII restriction. The presence of integrons was determined by PCR amplification of three integrase genes, as well as gene cassettes, and the qacEDelta1-sulI region. Thirty-seven Aeromonas spp. isolates were differentiated into six species by aroA PCR-RFLP, i.e., A. veronii biovar sobria, A. hydrophila, A. encheleia, A. ichtiosoma, A. salmonicida, and A. media. High levels of resistance to tetracycline (78.3%), amoxicillin (89.2%), and augmentin (86.5%) were observed. Decreased susceptibility to erythromycin was observed for 67.6% of isolates. Although 45.9% of isolates displayed nalidixic acid resistance, majority of isolates were susceptible to the fluoroquinolones. The MAR index ranged from 0.12 to 0.59, with majority of isolates indicating high-risk contamination originating from humans or animals where antibiotics are often used. Plasmids were detected in 21 isolates, with 14 of the isolates displaying multiple plasmid profiles. Single and multiple class A family Tet determinants were observed in 27% and 48.7% of isolates, respectively, with Tet A being the most prevalent Tet determinant type. Class 1 integron and related structures were amplified and carried different combinations of the antibiotic resistance gene cassettes ant(3'')Ia, aac(6')Ia, dhfr1, oxa2a and/or pse1. Class 2 integrons were also amplified, but the

  17. Virulent Aeromonas hydrophila in channel catfish

    Science.gov (United States)

    In this study, we investigated factors that predisposed catfish to motile aeromonas septicemia (MAS) caused by virulent Aeromonas hydrophila (vAh). Our results revealed that wounding on fish body surface was a prerequisite for vAh infection and disease development. A reproducible waterborne challeng...

  18. Development of a markerless deletion system for the fish-pathogenic bacterium Flavobacterium psychrophilum.

    Science.gov (United States)

    Gómez, Esther; Álvarez, Beatriz; Duchaud, Eric; Guijarro, José A

    2015-01-01

    Flavobacterium psychrophilum is a Gram-negative fish pathogen that causes important economic losses in aquaculture worldwide. Although the genome of this bacterium has been determined, the function and relative importance of genes in relation to virulence remain to be established. To investigate their respective contribution to the bacterial pathogenesis, effective tools for gene inactivation are required. In the present study, a markerless gene deletion system has been successfully developed for the first time in this bacterium. Using this method, the F. psychrophilum fcpB gene, encoding a predicted cysteine protease homologous to Streptococcus pyogenes streptopain, was deleted. The developed system involved the construction of a conjugative plasmid that harbors the flanking sequences of the fcpB gene and an I-SceI meganuclease restriction site. Once this plasmid was integrated in the genome by homologous recombination, the merodiploid was resolved by the introduction of a plasmid expressing I-SceI under the control of the fpp2 F. psychrophilum inducible promoter. The resulting deleted fcpB mutant presented a decrease in extracellular proteolytic activity compared to the parental strain. However, there were not significant differences between their LD50 in an intramuscularly challenged rainbow trout infection model. The mutagenesis approach developed in this work represents an improvement over the gene inactivation tools existing hitherto for this "fastidious" bacterium. Unlike transposon mutagenesis and gene disruption, gene markerless deletion has less potential for polar effects and allows the mutation of virtually any non-essential gene or gene clusters.

  19. Development of a markerless deletion system for the fish-pathogenic bacterium Flavobacterium psychrophilum.

    Directory of Open Access Journals (Sweden)

    Esther Gómez

    Full Text Available Flavobacterium psychrophilum is a Gram-negative fish pathogen that causes important economic losses in aquaculture worldwide. Although the genome of this bacterium has been determined, the function and relative importance of genes in relation to virulence remain to be established. To investigate their respective contribution to the bacterial pathogenesis, effective tools for gene inactivation are required. In the present study, a markerless gene deletion system has been successfully developed for the first time in this bacterium. Using this method, the F. psychrophilum fcpB gene, encoding a predicted cysteine protease homologous to Streptococcus pyogenes streptopain, was deleted. The developed system involved the construction of a conjugative plasmid that harbors the flanking sequences of the fcpB gene and an I-SceI meganuclease restriction site. Once this plasmid was integrated in the genome by homologous recombination, the merodiploid was resolved by the introduction of a plasmid expressing I-SceI under the control of the fpp2 F. psychrophilum inducible promoter. The resulting deleted fcpB mutant presented a decrease in extracellular proteolytic activity compared to the parental strain. However, there were not significant differences between their LD50 in an intramuscularly challenged rainbow trout infection model. The mutagenesis approach developed in this work represents an improvement over the gene inactivation tools existing hitherto for this "fastidious" bacterium. Unlike transposon mutagenesis and gene disruption, gene markerless deletion has less potential for polar effects and allows the mutation of virtually any non-essential gene or gene clusters.

  20. Aeromonas hydrophila and Aeromonas veronii predominate among potentially pathogenic ciprofloxacin- and tetracycline-resistant aeromonas isolates from Lake Erie.

    Science.gov (United States)

    Skwor, Troy; Shinko, Jasmine; Augustyniak, Alexander; Gee, Christopher; Andraso, Greg

    2014-02-01

    Members of the genus Aeromonas are ubiquitous in nature and have increasingly been implicated in numerous diseases of humans and other animal taxa. Although some species of aeromonads are human pathogens, their presence, density, and relative abundance are rarely considered in assessing water quality. The objectives of this study were to identify Aeromonas species within Lake Erie, determine their antibiotic resistance patterns, and assess their potential pathogenicity. Aeromonas strains were isolated from Lake Erie water by use of Aeromonas selective agar with and without tetracycline and ciprofloxacin. All isolates were analyzed for hemolytic ability and cytotoxicity against human epithelial cells and were identified to the species level by using 16S rRNA gene restriction fragment length polymorphisms and phylogenetic analysis based on gyrB gene sequences. A molecular virulence profile was identified for each isolate, using multiplex PCR analysis of six virulence genes. We demonstrated that Aeromonas comprised 16% of all culturable bacteria from Lake Erie. Among 119 Aeromonas isolates, six species were identified, though only two species (Aeromonas hydrophila and A. veronii) predominated among tetracycline- and ciprofloxacin-resistant isolates. Additionally, both of these species demonstrated pathogenic phenotypes in vitro. Virulence gene profiles demonstrated a high prevalence of aerolysin and serine protease genes among A. hydrophila and A. veronii isolates, a genetic profile which corresponded with pathogenic phenotypes. Together, our findings demonstrate increased antibiotic resistance among potentially pathogenic strains of aeromonads, illustrating an emerging potential health concern.

  1. Bacteriophage Resistance Mechanisms in the Fish Pathogen Flavobacterium psychrophilum: Linking Genomic Mutations to Changes in Bacterial Virulence Factors

    DEFF Research Database (Denmark)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Dalsgaard, Inger

    2015-01-01

    requires overcoming the selection for phage resistance in the bacterial populations. Here, we analyzed resistance mechanisms in F. psychrophilum after phage exposure using whole-genome sequencing of the ancestral phage-sensitive strain 950106-1/1 and six phage-resistant isolates. The phage...... resistance and the genetic modifications were supported by direct measurements of bacteriophage adsorption rates, biofilm formation, and secretion of extracellular enzymes, which were all impaired in the resistant strains, probably due to superficial structural changes. The clustered regularly interspaced...... short palindromic repeat (CRISPR) region was unaffected in the resistant isolates and thus did not play a role as a resistance mechanism for F. psychrophilum under the current conditions. All together, the results suggest that resistance in F. psychrophilum was driven by spontaneous mutations, which...

  2. Quorum sensing signal molecules (acylated homoserine lactones) in Gram-negative fish pathogenic bacteria

    DEFF Research Database (Denmark)

    Bruhn, Jesper Bartholin; Dalsgaard, Inger; Nielsen, K.F.

    2005-01-01

    and plant-pathogenic bacteria. A total of 59 strains, representing 9 different fish pathogenic species, were tested against 2 AHL monitor bacteria (Agrobacterium tumefaciens NT1 [pZLR4] and Chromobacterium violaceum CV026) in a well diffusion assay and by thin-layer chromatography (TLC). Representative...... salmonicida and Vibrio splendidus were also positive. Aeromonas species produced N-butanoyl homoserine lactone (BHL) and N-hexanoyl homoserine lactone (HHL) and 1 additional product, whereas N-3-oxo-hexanoyl homoserine lactone (OHHL) and HHL were detected in Vibrio salmonicida. N-3-oxo-octanoyl homoserine...... lactone (OOHL) and N-3-octanoyl homoserine lactone (OHL) were detected in Y. ruckeii. AHLs were not detected from strains of Photobacterium damselae, Flavobacterium psychrophilum or Moritella viscosa. AHLs were extracted from fish infected with Y. ruckeri but not from fish infected with A. salmonicida...

  3. Expression of Vibrio salmonicida virulence genes and immune response parameters in experimentally challenged Atlantic salmon (Salmo salar L.

    Directory of Open Access Journals (Sweden)

    Ane Mohn Bjelland

    2013-12-01

    Full Text Available The Gram-negative bacterium Vibrio salmonicida is the causative agent of cold-water vibriosis (CV, a hemorrhagic septicemia that primarily affects farmed Atlantic salmon (Salmo salar L.. The mechanisms of disease development, host specificity and adaptation, as well as the immunogenic properties of V. salmonicida are largely unknown. Therefore, to gain more knowledge on the pathogenesis of CV, 90 Atlantic salmon parr were injected intraperitonellay with 6 x 106 CFU of V. salmonicida LFI1238. Samples from blood and spleen tissue were taken at different time points throughout the challenge for gene expression analysis by two-step reverse transcription quantitative real-time polymerase chain reaction. Out of a panel of six housekeeping genes, accD, gapA and 16S rDNA were found to be the most suitable references for expression analysis in Vibrio salmonicida. The bacterial proliferation during challenge was monitored based on the expression of the 16S rRNA encoding gene. Before day 4, the concentrations of V. salmonicida in blood and spleen tissue demonstrated a lag phase. From day 4, the bacterial proliferation was exponential. The expression profiles of eight genes encoding potential virulence factors of V. salmonicida were studied. Surprisingly, all tested virulence genes were generally highest expressed in broth cultures compared to the in vivo samples. We hypothesize that this general muting of gene expression in vivo may be a strategy for V. salmonicida to hide from the host immune system. To further investigate this hypothesis, the expression profiles of eight genes encoding innate immune factors were analyzed. The results demonstrated a strong and rapid, but short-lasting innate immune response against V. salmonicida. These results suggest that the bacterium possesses mechanisms that inhibit and/or resist the salmon innate immune system until the host becomes exhausted of fighting the on-going and eventually overwhelming infection.

  4. Comparative analysis of the lux operons in Aliivibrio logei KCh1 (a Kamchatka Isolate) and Aliivibrio salmonicida.

    Science.gov (United States)

    Manukhov, Ilya V; Khrul'nova, Svetlana A; Baranova, Ancha; Zavilgelsky, Gennadii B

    2011-08-01

    Here we provide a molecular description of a new psychrophilic strain, KCh11, of marine luminescent bacteria classified as Aliivibrio logei. We sequenced the entire lux operon of A. logei KCh1 and showed that it is substantially similar to the lux operon of Aliivibrio salmonicida. It was demonstrated that the reduced production of bioluminescence in A. salmonicida is most likely defined by a specific defect in its luxD gene.

  5. Distribution of Aeromonas Species in the Intestinal Tracts of River Fish

    OpenAIRE

    1995-01-01

    Aeromonas isolates were obtained from fish intestines, water, and sediments from an urban river and identified by the DNA-DNA microplate hybridization method. The isolates were Aeromonas veronii (22%), Aeromonas caviae (18%), Aeromonas hydrophila (13%), Aeromonas sobria (8%), Aeromonas jandaei (7%), and other Aeromonas spp. (33%). Aeromonas species occurred at high densities with high incidences, regardless of season. The results strongly suggest that aeromonads are indigenous in fish intesti...

  6. antimicrobial susceptibility pattern of aeromonas hydrophila among ...

    African Journals Online (AJOL)

    DR. AMINU

    immediately leaving the treatment plant may contain between 0-102 ... Diseases associated with Aeromonas are intestinal ... major symptoms (diarrhea, vomiting and fever) and duration of ... cholera (Ramamurthy et al., 1992), all identified A.

  7. Comparative Genome Analysis Provides Insights into the Pathogenicity of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Dalsgaard, Inger;

    2016-01-01

    to describe the F. psychrophilum pan-genome and to examine virulence factors, prophages, CRISPR arrays, and genomic islands present in the genomes. Analysis of the genomic DNA sequences were complemented with selected phenotypic characteristics of the strains. The pan genome analysis showed that F......, independent of geographic location, year of isolation and source of isolates. Only one prophage-related sequence was found which corresponded to the previously described prophage 6H, and appeared in 5 out of 11 isolates. CRISPR array analysis revealed two different loci with dissimilar spacer content, which...

  8. Reproducible methods for experimental infection with Flavobacterium psychrophilum in rainbow trout Oncorhynchus mykiss

    DEFF Research Database (Denmark)

    Madsen, Lone; Dalsgaard, Inger

    1999-01-01

    Experiments were done in order to achieve a reproducible method that can be used to infect rainbow trout Oncorhynchus mykiss with Flavobacterium psychrophilum, the causal agent of coldwater disease and rainbow trout fry syndrome. The main method investigated was intraperitoneal injection......, and this method was tested using isolates with different elastin- degrading profiles and representing different serotypes. Injecting trout, average weight 1 g, with 10(4) CFU (colony- forming units) per fish caused cumulative mortalities around 60 to 70%. The virulent strains belonged to certain serotypes...

  9. Experimental induction of motile Aeromonas septicemia in channel catfish by waterborne challenge with virulent Aeromonas hydrophila

    Science.gov (United States)

    Motile Aeromonas septicemia (MAS), caused by virulent clonal isolates of Aeromonas hydrophila (vAh), is emerging as a major disease in catfish aquaculture in the Southeastern United States. Predisposing conditions leading to vAh infection in catfish were however largely unknown. The objective of thi...

  10. Infection and disease progress of motile Aeromonas septicemia caused by virulent Aeromonas hydrophila in channel catfish

    Science.gov (United States)

    Motile Aeromonas septicemia (MAS), caused by virulent clonal isolates of Aeromonas hydrophila (vAh), is emerging as a major disease in channel catfish (Ictalurus punctatus) aquaculture in the Southeastern United States. Predisposing conditions leading to vAh infection in catfish were however largely...

  11. Aeromonas flagella and colonisation mechanisms.

    Science.gov (United States)

    Lowry, Rebecca; Balboa, Sabela; Parker, Jennifer L; Shaw, Jonathan G

    2014-01-01

    Aeromonas species are inhabitants of aquatic environments and are able to cause disease in humans and fish among other animals. In aquaculture, they are responsible for the economically important diseases of furunculosis and motile Aeromonas septicaemia (MAS). Whereas gastroenteritis and wound infections are the major human diseases associated with the genus. As they inhabit and survive in diverse environments, aeromonads possess a wide range of colonisation factors. The motile species are able to swim in liquid environments through the action of a single polar flagellum, the flagellin subunits of which are glycosylated; although essential for function the biological role of glycan addition is yet to be determined. Approximately 60% of aeromonads possess a second lateral flagella system that is expressed in viscous environments for swarming over surfaces; both flagellar systems have been shown to be important in the initial colonisation of surfaces. Subsequently, other non-flagellar colonisation factors are employed; these can be both filamentous and non-filamentous. The aeromonads possess a number of fimbrial systems with the bundle-forming MSHA type IV pilus system, having a major role in human cell adherence. Furthermore, a series of outer-membrane proteins have also been implicated in the aeromonad adhesion process. A number of strains are also capable of cell invasion and that maybe linked with the more invasive diseases of bacteraemia or wound infections. These strains employ cell surface factors that allow the colonisation of these niches that protect them from the host's immune system such as S-layers, capsules or particular lipopolysaccharides.

  12. Effect of hydrogen peroxide and/or Flavobacterium psychrophilum on the gills of rainbow trout, Oncorhynchus mykiss (Walbaum)

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi; Kania, P. W.; Buchmann, K.

    2015-01-01

    The immune response and morphological changes in the gills of rainbow trout fry after immersion in hydrogen peroxide (H2O2), Flavobacterium psychrophilum or combined exposure were examined. The gills were sampled 4, 48, 125 and 192 h after exposure, and the regulation of expression of the following...

  13. Phage-Host Interactions in Flavobacterium psychrophilum and the Potential for Phage Therapy in Aquaculture

    DEFF Research Database (Denmark)

    Christiansen, Rói Hammershaimb

    Abstract The disease rainbow trout fry syndrome (RTFS) is caused by the bacterial fish pathogen Flavobacterium psychrophilum, which for decades has been the cause of great losses of rainbow trout in aquacultures both in Denmark and around the world. Disease outbreaks are typically seen at water...

  14. Recombinant expression and purification of an ATP-dependent DNA ligase from Aliivibrio salmonicida.

    Science.gov (United States)

    Williamson, Adele; Pedersen, Hege

    2014-05-01

    The genome of the psychrophilic fish-pathogen Aliivibrio salmonicida encodes a putative ATP-dependent DNA ligase in addition to a housekeeping NAD-dependent enzyme. In order to study the structure and activity of the ATP dependent ligase in vitro we have undertaken its recombinant production and purification from an Escherichia coli based expression system. Expression and purification of this protein presented two significant challenges. First, the gene product was moderately toxic to E. coli cells, second it was necessary to remove the large amounts of E. coli DNA present in bacterial lysates without contamination of the protein preparation by nucleases which might interfere with future assaying. The toxicity problem was overcome by fusion of the putative ligase to large solubility tags such as maltose-binding protein (MBP) or Glutathione-S-transferase (GST), and DNA was removed by treatment with a nuclease which could be inhibited by reducing agents. As the A. salmonicida ATP-dependent DNA ligase gene encodes a predicted leader peptide, both the full-length and mature forms of the protein were produced. Both possessed ATP-dependent DNA ligase activity, but the truncated form was significantly more active. Here we detail the first reported production, purification and preliminary characterization of active A. salmonicida ATP-dependent DNA ligase.

  15. Interlaboratorium vergelijking van het onderzoek naar Aeromonas spp. in drinkwater

    NARCIS (Netherlands)

    Havelaar AH; During M; Versteegh JFM

    1986-01-01

    Door middel van onderzoek van zes kunstmatig besmette gesimuleerde monsters drinkwater ( 4 Aeromonas spp., 1 Klebsiella oxytoca, 1 Pseudomonas aeruginosa) werd een vergelijking gemaakt van de resultaten van Aeromonas onderzoek in 14 laboratoria. De tellingen in de deelnemende laboratoria vertoonde

  16. Biliary tract infections caused by Aeromonas species.

    Science.gov (United States)

    Chao, C M; Lai, C C; Tang, H J; Ko, W C; Hsueh, P-R

    2013-02-01

    This study investigated the clinical and microbiological characteristics of patients with Aeromonas infections of the biliary tract. Patients with bile cultures positive for Aeromonas species during the period July 2004 to December 2011 were identified from a computerized database of a hospital in Taiwan. Patients with Aeromonas infections of the biliary tract were further identified. During the study period, a total of 1,142 isolates of Aeromonas species were obtained from 750 patients. Of those patients, 91 (12.1 %) had Aeromonas infections of the biliary tract. The annual incidence (episodes per 10,000 patient-days) of biliary tract infections caused by all Aeromonas species was 0.31 in 2007, 0.12 in 2010, and 0.27 in 2011. A. hydrophila was the most common species isolated (n = 41, 45.1 %), followed by A. caviae (n = 30, 33.0 %), A. veronii biovar sobria (n = 15, 16.5 %), and A. veronii biovar veronii (n = 5, 5.5 %). The majority of patients (n = 77, 84.6 %) had polymicrobial infections. Hepatobiliary stones (n = 50, 54.9 %) and hepatobiliary cancer (n = 38, 41.8 %) were the most common underlying diseases, followed by diabetes mellitus (n = 29, 31.9 %) and liver cirrhosis (n = 7, 7.7 %). The in-hospital mortality rate was 8.8 %. Infection-related mortality was associated with underlying immunocompromised condition (p = 0.044) and use of mechanical ventilation (p = 0.004), but was not associated with inappropriate antibiotic usage or concomitant bacteremia (n = 8, 8.8 %). In conclusion, biliary tract infections caused by Aeromonas species are not uncommon and can develop in both immunocompromised and immunocompetent patients; however, patients with underlying hepatobiliary diseases are particularly susceptible to these infections.

  17. Adhesion of smooth and rough phenotypes of Flavobacterium psychrophilum to polystyrene surfaces.

    Science.gov (United States)

    Högfors-Rönnholm, E; Norrgård, J; Wiklund, T

    2015-05-01

    Phenotypic smooth cells of the fish pathogenic bacterium Flavobacterium psychrophilum have previously been reported to be more adhesive to polystyrene surfaces than corresponding rough cells. In this study, the adhesion ability of smooth and rough cells of F. psychrophilum to polystyrene surfaces was investigated in detail with a crystal violet staining method. By treating both polystyrene surfaces with fish mucus and carbohydrates and the bacterial cells with carbohydrates, the involvement of lectins in the adhesion process was investigated. Smooth cells showed significantly higher adhesion ability to untreated polystyrene surfaces compared with corresponding rough cells and increasing water hardness had an inhibitory effect on the adhesion. Treatment of polystyrene surfaces with D-glucose, D-galactose and fish mucus increased the adhesion ability of smooth cells to polystyrene. Furthermore, treatment of the smooth cells with D-glucose, D-galactose and sialic acid decreased the adhesion ability of the cells, indicating that the adhesion is likely mediated by complementary lectins on the surface of the cells. Sodium (meta)periodate treatment of smooth cells also decreased the adhesion ability to polystyrene, suggesting that the lectins, such as the dominating sialic acid-binding lectin, are probably localized in the extracellular polysaccharides surrounding the cells.

  18. Characterization of mercury-resistant clinical Aeromonas species

    Directory of Open Access Journals (Sweden)

    Abigail Pérez-Valdespino

    2013-12-01

    Full Text Available Mercury-resistant Aeromonas strains isolated from diarrhea were studied. Resistance occurs via mercuric ion reduction but merA and merR genes were only detected in some strains using PCR and dot hybridization. Results indicate a high variability in mer operons in Aeromonas. To our knowledge, this is the first report of mercury-resistant clinical Aeromonas strains.

  19. Characterization of mercury-resistant clinical Aeromonas species.

    Science.gov (United States)

    Pérez-Valdespino, Abigail; Celestino-Mancera, Martin; Villegas-Rodríguez, Viridiana Lorena; Curiel-Quesada, Everardo

    2013-12-01

    Mercury-resistant Aeromonas strains isolated from diarrhea were studied. Resistance occurs via mercuric ion reduction but merA and merR genes were only detected in some strains using PCR and dot hybridization. Results indicate a high variability in mer operons in Aeromonas. To our knowledge, this is the first report of mercury-resistant clinical Aeromonas strains.

  20. Development of duplex-PCR for identification of Aeromonas species

    Directory of Open Access Journals (Sweden)

    Carina Lucena Mendes-Marques

    2013-10-01

    Full Text Available Introduction The number of reports of intestinal infections caused by Aeromonas spp. has increased significantly in recent years. In most clinical laboratories, identification of these bacteria is carried out by general phenotypic tests that sometimes do not accurately differentiate Aeromonas and Vibrio. Methods A duplex-polymerase chain reaction (PCR was developed directed to 2 targets identifying Aeromonas spp. pathogenic to humans. Results The duplex-PCR results were reproducible and specific for Aeromonas spp. pathogenic to humans. Conclusions This method will allow differentiation between Vibrio and Aeromonas spp. in patients with in cholera-like symptoms and can also be used in water quality monitoring.

  1. Development of duplex-PCR for identification of Aeromonas species

    Directory of Open Access Journals (Sweden)

    Carina Lucena Mendes-Marques

    2013-05-01

    Full Text Available Introduction The number of reports of intestinal infections caused by Aeromonas spp. has increased significantly in recent years. In most clinical laboratories, identification of these bacteria is carried out by general phenotypic tests that sometimes do not accurately differentiate Aeromonas and Vibrio. Methods A duplex-polymerase chain reaction (PCR was developed directed to 2 targets identifying Aeromonas spp. pathogenic to humans. Results The duplex-PCR results were reproducible and specific for Aeromonas spp. pathogenic to humans. Conclusions This method will allow differentiation between Vibrio and Aeromonas spp. in patients with in cholera-like symptoms and can also be used in water quality monitoring.

  2. Aeromonas caviae septicemia in immunocompetent gastrointestinal carriers

    Directory of Open Access Journals (Sweden)

    M. Dwivedi

    2008-12-01

    Full Text Available Aeromonas caviae strains have been isolated from blood and stool cultures of three immunocompetent patients, residents of Northern India, who presented with community acquired septicemia without any recent history of diarrhea. Cell culture infectivity test performed on Hep-2 cells have shown substantial degree of invasiveness in the isolated strains. This case unleashes a possibility of asymptomatic gastrointestinal carriage of such strains of A. caviae in a very large population of India, as several areas of India have very high rates of Aeromonas induced acute diarrhea/gastroenteritis (up to 13%. It needs to be appraised further in India as well as other countries having high rates of Aeromonas induced acute diarrhea/gastroenteritis.

  3. Aeromonas caviae septicemia in immunocompetent gastrointestinal carriers

    Directory of Open Access Journals (Sweden)

    M. Dwivedi

    Full Text Available Aeromonas caviae strains have been isolated from blood and stool cultures of three immunocompetent patients, residents of Northern India, who presented with community acquired septicemia without any recent history of diarrhea. Cell culture infectivity test performed on Hep-2 cells have shown substantial degree of invasiveness in the isolated strains. This case unleashes a possibility of asymptomatic gastrointestinal carriage of such strains of A. caviae in a very large population of India, as several areas of India have very high rates of Aeromonas induced acute diarrhea/gastroenteritis (up to 13%. It needs to be appraised further in India as well as other countries having high rates of Aeromonas induced acute diarrhea/gastroenteritis.

  4. Development of a gene transfer system for curing of plasmids in the marine fish pathogen Vibrio salmonicida.

    Science.gov (United States)

    Valla, S; Frydenlund, K; Coucheron, D H; Haugan, K; Johansen, B; Jørgensen, T; Knudsen, G; Strøm, A

    1992-01-01

    All reported natural isolates of the marine fish pathogen Vibrio salmonicida contain plasmids, and in another marine fish pathogen, Vibrio anguillarum, it has been shown that a plasmid is important for expression of virulence by the organism. To study the function of the plasmids in V. salmonicida, we developed a gene transfer system based on the plasmid RSF1010 replicon. The gene transfer system was used to construct a plasmid-free strain, and this strain was found to behave similarly to the wild type in a fish pathogenicity test based on intraperitoneal injection of the bacteria. We were unable to detect any other phenotypic differences between the two strains. It could therefore be concluded that at least in the V. salmonicida strain tested, extrachromosomal DNA is not required for expression of virulence. Images PMID:1622274

  5. Herida antebraquial infectada por Aeromonas hydrophila

    OpenAIRE

    1995-01-01

    Se presenta un caso de celulitis por Aeromonas hydrophila, en un paciente de 23 años, tras una herida antebraquial producida en el medio acuático. La celulitis se resolvió mediante desbridamiento agresivo y quimioterapia. En los controles posteriores no se han apreciado déficits funcionales tras la infección. A case of Aeromonas hidrophila cellulitis developped in a 23-year-old patient, after aquatic environment forearm wound is presented. His cellulitis was effectively resolve...

  6. Different Phenotypes of Mature Biofilm in Flavobacterium psychrophilum Share a Potential for Virulence That Differs from Planktonic State

    Science.gov (United States)

    Levipan, Héctor A.; Avendaño-Herrera, Ruben

    2017-01-01

    Flavobacterium psychrophilum is the etiological agent of bacterial coldwater disease and the rainbow trout fry syndrome in salmonid aquaculture worldwide. However, there have been few studies into the capacity of F. psychrophilum to form biofilms and how these cellular accretions differ from planktonic cells or how they affect potential virulence. We evaluated the biofilm formation by three Chilean isolates of F. psychrophilum (LM-02-Fp, LM-06-Fp, and LM-13-Fp) and two non-Chilean strains (JIP02/86 and NCMB1947T), and compared biofilm and planktonic states to obtain insights into expression differences of virulence- and biofilm-related genes (VBRGs). Our findings are based on scanning confocal laser microscopy (SCLM) and LIVE/DEAD staining, enzymatic reactions, reverse transcription-quantitative PCR (RT-qPCR) of genes encoding putative virulence factors, and transcriptomes (RNA-Seq). The LM-02-Fp and NCMB1947T strains were the strongest and weakest biofilm producers, respectively. The strong-biofilm producer showed different physiological cell states distributed in different layers of mature biofilms, whereas the NCMB1947T biofilms consisted of cells arranged in a monolayer. WGA-binding exopolysaccharides would be the main components of their corresponding extracellular matrices. Transcriptomes of F. psychrophilum NCMB1947T and LM-02-Fp were clustered by state (biofilm vs. planktonic) rather than by strain, indicating important state-dependent differences in gene expression. Analysis of differentially expressed genes between states identified putative VBRGs involved in polysaccharide biosynthesis, lateral gene transfer, membrane transport (e.g., for drugs and Fe3+), sensory mechanisms, and adhesion, and indicated that about 60–100% of VBRGs involved in these processes was significantly upregulated in the biofilm state. Conversely, upregulated motility-related genes in the biofilm state were not identified, whereas a lower fraction of proteolysis-related genes (33

  7. Re-identification of Aeromonas isolates from rainbow trout and incidence of class 1 integron and β-lactamase genes.

    Science.gov (United States)

    Vega-Sánchez, Vicente; Latif-Eugenín, Fadua; Soriano-Vargas, Edgardo; Beaz-Hidalgo, Roxana; Figueras, María José; Aguilera-Arreola, Ma Guadalupe; Castro-Escarpulli, Graciela

    2014-08-27

    Forty-eight Aeromonas isolates from rainbow trout previously identified by the 16S rDNA-RFLP technique were re-identified using 2 housekeeping genes (gyrB and rpoD). After sequencing the prevalences of the species were A. veronii (29.2%), A. bestiarum (20.8%), A. hydrophila (16.7%), A. sobria (10.4%), A. media (8.3%), A. popoffii (6.2%), A. allosaccharophila (2.1%), A. caviae (2.1%), A. salmonicida (2.1%) and one isolate (2.1%) belongs to a candidate new species "Aeromonas lusitana". Coincident identification results to the 16S rDNA-RFLP technique were only obtained for 68.8% of the isolates. PCR amplification of the enterobacterial repetitive intergenic consensus (ERIC-PCR) indicated that the 48 isolates belonged to 33 different ERIC genotypes. Several genotypes were isolated from different farms and organs in the same fish, indicating a systemic dissemination of the bacteria. The presence of genes (blaIMP, blaCphA/IMIS, blaTEM, blaSHV and intI1) that encode extended-spectrum beta-lactamases (ESBLs), metallo-beta-lactamases (MBLs) and class 1 integrons were studied by PCR. Only 39.6% (19/48) of the strains showed the presence of one or more resistance genes. The gene blaCphA/IMIS was detected in 29.2% of the isolates, followed by the intI1 (6.2%) and blaSHV (4.2%) genes. The variable region of class 1 integrons of the 3 positive isolates was sequenced revealing the presence of the gene cassette aadA1 (aminoglycoside transferase) that plays a role in streptomycin/spectinomycin resistance.

  8. A novel lux operon in the cryptically bioluminescent fish pathogen Vibrio salmonicida is associated with virulence.

    Science.gov (United States)

    Nelson, Eric J; Tunsjø, Hege S; Fidopiastis, Pat M; Sørum, Henning; Ruby, Edward G

    2007-03-01

    The cold-water-fish pathogen Vibrio salmonicida expresses a functional bacterial luciferase but produces insufficient levels of its aliphatic-aldehyde substrate to be detectably luminous in culture. Our goals were to (i) better explain this cryptic bioluminescence phenotype through molecular characterization of the lux operon and (ii) test whether the bioluminescence gene cluster is associated with virulence. Cloning and sequencing of the V. salmonicida lux operon revealed that homologs of all of the genes required for luminescence are present: luxAB (luciferase) and luxCDE (aliphatic-aldehyde synthesis). The arrangement and sequence of these structural lux genes are conserved compared to those in related species of luminous bacteria. However, V. salmonicida strains have a novel arrangement and number of homologs of the luxR and luxI quorum-sensing regulatory genes. Reverse transcriptase PCR analysis suggests that this novel arrangement of quorum-sensing genes generates antisense transcripts that may be responsible for the reduced production of bioluminescence. In addition, infection with a strain in which the luxA gene was mutated resulted in a marked delay in mortality among Atlantic salmon relative to infection with the wild-type parent in single-strain challenge experiments. In mixed-strain competition between the luxA mutant and the wild type, the mutant was attenuated up to 50-fold. It remains unclear whether the attenuation results from a direct loss of luciferase or a polar disturbance elsewhere in the lux operon. Nevertheless, these findings document for the first time an association between a mutation in a structural lux gene and virulence, as well as provide a new molecular system to study Vibrio pathogenesis in a natural host.

  9. Influence of organic diets and probiotics on an experimental Flavobacterium psychrophilum infection in rainbow trout fry

    DEFF Research Database (Denmark)

    Madsen, Lone; Ingerslev, Hans-Christian; Boye, Mette

    2012-01-01

    following exposure to pathogenic microorganisms. The aim of the Danish project OPTIFISH is to optimize growth and survival for organic cultured rainbow trout. OPTIFISH investigates how organic vs. non-organic diet types as well as diets with or without probiotics affect the intestine, the intestinal...... of fry to pathogens, e.g. F .psychrophilum. In the current experiment four diet types were tested on fry, a conventional type (Inicio®, BioMar A/S) with and without probiotics, as well as an organic type with and without probiotic. Bactocell® (Lallemand) was used as the probiotic. Studies were done...... been fed diets that were organic or conventional nor if the feed had been added probiotic. No significance in mortalities was seen between the diet groups. The bacteriological examinations showed that the bacterium had entered the fish, as it was found in inner organs in one fourth of the sampled fish...

  10. Effect of Bacteriophages on the Growth of Flavobacterium psychrophilum and Development of Phage-Resistant Strains.

    Science.gov (United States)

    Christiansen, Rói Hammershaimb; Madsen, Lone; Dalsgaard, Inger; Castillo, Daniel; Kalatzis, Panos G; Middelboe, Mathias

    2016-05-01

    The controlling effect of single and multiple phages on the density of Flavobacterium psychrophilum at different initial multiplicity of infection (MOI) was assessed in batch cultures to explore the potential for phage-based treatment of this important fish pathogen. A high initial phage concentration (MOI = 0.3-4) was crucial for efficient viral lysis, resulting in a 10(4)-10(5)-fold reduction of phage-sensitive cells (both single phages and phage cocktails), which was maintained throughout the incubation (>10 days). Following cell lysis, regrowth of phage-resistant strains was examined and resistant strains were isolated for further characterization. The application of a mathematical model allowed simulation of phage-host interactions and resistance development, confirming indications from strain isolations that phage-sensitive strains dominated the regrowing population (>99.8%) at low MOI and phage-resistant strains (>87.8%) dominated at high MOI. A cross-infectivity test covering 68 isolated strains and 22 phages resulted in 23 different host susceptibility patterns, with 20 of the isolates being resistant to all the applied phages. Eleven isolated strains with different susceptibility patterns had lower growth rates (0.093 to 0.31 h(-1)) than the host strain (0.33 h(-1)), while 10 of 14 examined strains had lost the ability to take up specific substrates as shown by BIOLOG profiles. Despite increased selection for phage resistance at high MOI, the results emphasize that high initial MOI is essential for fast and effective control of F. psychrophilum infection and suggest that the small populations of resistant clones had reduced competitive abilities relative to the sensitive ancestral strain.

  11. Quorum Sensing Regulation in Aeromonas hydrophila

    DEFF Research Database (Denmark)

    Garde, Christian; Bjarnsholt, Thomas; Givskov, Michael;

    2010-01-01

    We present detailed results on the C4-HSL-mediated quorum sensing (QS) regulatory system of the opportunistic Gram-negative bacterium Aeromonas hydrophila. This bacterium contains a particularly simple QS system that allows for a detailed modeling of kinetics. In a model system (i...

  12. Multilocus phylogenetic analysis of the genus Aeromonas.

    Science.gov (United States)

    Martinez-Murcia, Antonio J; Monera, Arturo; Saavedra, M Jose; Oncina, Remedios; Lopez-Alvarez, Monserrate; Lara, Erica; Figueras, M Jose

    2011-05-01

    A broad multilocus phylogenetic analysis (MLPA) of the representative diversity of a genus offers the opportunity to incorporate concatenated inter-species phylogenies into bacterial systematics. Recent analyses based on single housekeeping genes have provided coherent phylogenies of Aeromonas. However, to date, a multi-gene phylogenetic analysis has never been tackled. In the present study, the intra- and inter-species phylogenetic relationships of 115 strains representing all Aeromonas species described to date were investigated by MLPA. The study included the independent analysis of seven single gene fragments (gyrB, rpoD, recA, dnaJ, gyrA, dnaX, and atpD), and the tree resulting from the concatenated 4705 bp sequence. The phylogenies obtained were consistent with each other, and clustering agreed with the Aeromonas taxonomy recognized to date. The highest clustering robustness was found for the concatenated tree (i.e. all Aeromonas species split into 100% bootstrap clusters). Both possible chronometric distortions and poor resolution encountered when using single-gene analysis were buffered in the concatenated MLPA tree. However, reliable phylogenetic species delineation required an MLPA including several "bona fide" strains representing all described species.

  13. Aeromonas spp.: ubiquitous or specialized bugs?

    Science.gov (United States)

    Martino, Maria Elena; Fasolato, Luca; Montemurro, Filomena; Novelli, Enrico; Cardazzo, Barbara

    2014-04-01

    The genus Aeromonas comprises ubiquitous bacteria that are known to play several roles in the environment. These bacteria were first described as fish pathogens, but their presence was documented in other reservoirs, such as animals and humans. Today, these bacteria are described as emerging pathogens, but their effective role in human pathogenicity is still controversial. In addition, their taxonomy is heavily debated, as species distinction is often difficult to achieve. To study the interspecies relationships and to investigate their connection with the environment, a multilocus sequence typing scheme previously developed for Aeromonas spp. was applied to 258 strains, and the genetic data were analysed by population software. Sampling was a fundamental step, including several of the main sources of Aeromonas: fish, food products and human cases of disease. The objective was to characterize the isolates and to find potential associations among them according to the following: species, sharing of virulence factors, source and adaptation to a specific habitat. The strains were characterized and demonstrated exceptionally high nucleotide variability in the Aeromonas genus. Among the sampled sources, different species distributions were found, highlighting the occurrence of adaptation processes towards specific habitats.

  14. Aeromonas chitinase degrades chironomid egg masses.

    Science.gov (United States)

    Laviad, Sivan; Golan, Amnon; Shaked, Tamar; Vaizel-Ohayon, Dalit; Halpern, Malka; Pick, Elah

    2016-02-01

    Chironomids are freshwater insects that undergo a complete metamorphosis of four life stages. Chironomid egg masses can be degraded by Vibrio cholerae and some Aeromonas species. Egg mass degradation by V. cholerae requires haemagglutinin protease activity. Our aim was to identify the egg mass degrading (EMD) factor secreted by Aeromonas dhkanesis 3K1C15. Following the hypothesis that the EMD factor of A. dhkanesis is also a protease, secreted proteases were screened, but none of them proved to have the same properties as the EMD factor. Using conventional protein purification methods, we found that the active fraction included chitinases. We further confirmed chitin as a building block of the egg masses. Interestingly, by supplementing bacterial growth media with chitin, we observed unexpected EMD factor activity in Aeromonas isolates that initially were not able to degrade egg masses. Accordingly, we concluded that although strain 3K1C15 secretes chitinases constitutively, most Aeromonas strains secrete chitinases inductively. Induction of chitinases in nature presumably occurs when bacteria are attached to the egg mass habitat, in which chitin is abundant. Considering that chitinases are highly conserved across bacteria phyla, we assume that the role of this enzyme in the bacteria-insect interplay could be wider than is currently thought.

  15. Estudio de los sideróforos y de las proteinas receptoras producidas por las bacterias patógenas de peces: "Photobacterium damselae subsp.psicicida y Aeromonas salmonicida subsp.salmonicida"

    OpenAIRE

    Valderrama Pereira, Andrea Katherine

    2016-01-01

    [Resumo] A continuación preséntase o resumo de cada un dos capítulos que fan parte desta tese doutoral. Capítulo I: Nesta sección descríbese a importancia da acuicultura a nivel mundial e as enfermidades causadas polas bacterias patóxenas que producen grandes perdas económicas a esta industria. Do mesmo modo, abórdase o tratamento destas enfermidades e a posibilidade de usar os mecanismos de captación de ferro para desenvolver novas vacinas e antimicrobiáns. Por último...

  16. MONITORING FOR AEROMONAS SPECIES AFTER TREATMENT WITH COMMON DRINKING WATER DISINFECTANTS

    Science.gov (United States)

    The sensitivity of Aeromonas spp. To free chlorine, chloramine and ultraviolet (UV) disinfection was determined. Aeromonas hydrophila is a contaminant listed on the USEPA's 1998 Contaminant Candidate List (CCL). Experiments using free chlorine indicated that the Aeromonas spp. ...

  17. MONITORING FOR AEROMONAS SPECIES AFTER TREATMENT WITH COMMON DRINKING WATER DISINFECTANTS

    Science.gov (United States)

    The sensitivity of Aeromonas spp. To free chlorine, chloramine and ultraviolet (UV) disinfection was determined. Aeromonas hydrophila is a contaminant listed on the USEPA's 1998 Contaminant Candidate List (CCL). Experiments using free chlorine indicated that the Aeromonas spp. ...

  18. Neutrophil Migration in the Activation of the Innate Immune Response to Different Flavobacterium psychrophilum Vaccines in Zebrafish (Danio rerio

    Directory of Open Access Journals (Sweden)

    Camila J. Solís

    2015-01-01

    Full Text Available Flavobacterium psychrophilum is a Gram-negative bacterium, responsible for the bacterial cold-water disease and the rainbow trout fry syndrome in freshwater salmonid fish. At present, there is only one commercial vaccine in Chile, made with two Chilean F. psychrophilum isolates and another licensed in Europe. The present study analyzed neutrophil migration, as a marker of innate immune activation, in zebrafish (Danio rerio in response to different F. psychrophilum bath vaccines, which is the first step in evaluating vaccine effectiveness and efficiency in fish. Results indicated that bacterins of the LM-02-Fp isolate were more immunogenic than those from the LM-13-Fp isolate. However, no differences were observed between the same bacteria inactivated by either formaldehyde or heat. Importantly, the same vaccine formulation without an adjuvant only triggered a mild neutrophil migration compared to the complete vaccine. Observations also found that, after a year of storage at 4°C, the activation of the innate immune system by the different vaccines was considerably decreased. Finally, new vaccine formulations prepared with heat and formaldehyde inactivated LM-02-Fp were significantly more efficient than the available commercial vaccine in regard to stimulating the innate immune system.

  19. Dispersal and Survival of Flavobacterium psychrophilum Phages In Vivo in Rainbow Trout and In Vitro under Laboratory Conditions: Implications for Their Use in Phage Therapy

    DEFF Research Database (Denmark)

    Madsen, Lone; Bertelsen, Sif K.; Dalsgaard, Inger

    2013-01-01

    Attention has been drawn to phage therapy as an alternative approach for controlling pathogenic bacteria such as Flavobacterium psychrophilum in salmonid aquaculture, which can give rise to high mortalities, especially in rainbow trout fry. Recently, phages have been isolated with a broad host...... range and a strong lytic potential against pathogenic F. psychrophilum under experimental conditions. However, little is known about the fate of phages at environmental conditions. Here, we quantified the dispersal and fate of F. psychrophilum phages and hosts in rainbow trout fry after intraperitoneal...... injection. Both phages and bacteria were isolated from the fish organs for up to 10 days after injection, and coinjection with both bacteria and phages resulted in a longer persistence of the phage in the fish organs, than when the fish had been injected with the phages only. The occurrence of both phage...

  20. Aeromonas Hydrophila: A Re-Emerging Pathogen

    Digital Repository Service at National Institute of Oceanography (India)

    Lakshmanaperumalsamy, P.; Thayumanavan, T.; Subashkumar, R.

    been initiated by their importance as fish pathogens or as a potential pathogen of humans and have, therefore, tended to focus on commercial and sport fisheries and recreational waters. Mesophilic aeromonads are halotolerant and are associated... role of species of A. hydrophila as a cause of human infections. During monsoon season, increased incidence of A. hydrophila was reported (Vivekanandhan et al., 2004). The much higher incidence of Aeromonas sp. in foods purchased at retail outlets...

  1. Aeromonas dhakensis, an increasingly recognized human pathogen

    Directory of Open Access Journals (Sweden)

    Po Lin eChen

    2016-05-01

    Full Text Available Aeromonas dhakensis was first isolated from children with diarrhea in Dhaka, Bangladesh and described in 2002. In the past decade, increasing evidence indicate this species is widely distributed in the environment and can cause a variety of infections both in human and animals, especially in coastal areas. A. dhakensis is often misidentified as A. hydrophila, A. veronii or A. caviae by commercial phenotypic tests in the clinical laboratory. Correct identification relies on molecular methods. Increasingly used matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS may be able to identify Aeromonas specie rapidly and accurately. A. dhakensis has shown its potent virulence in different animal models and clinical infections. Although several virulence factors had been reported, no single mechanism is conclusive. Characteristically A. dhakensis is the principal species causing soft tissue infection and bacteremia, especially among patients with liver cirrhosis or malignancy. Of note, A. dhakensis bacteremia is more lethal than bacteremia due to other Aeromonas species. The role of this species in gastroenteritis remains controversial. Third generation cephalosporins and carbapenems should be used cautiously in the treatment of severe A. dhakensis infection due to the presence of AmpC β-lactamase and metallo-β-lactamase genes, and optimal regimens may be cefepime or fluoroquinolones. Studies of bacterial virulence factors and associated host responses may provide the chance to understand the heterogeneous virulence between species. The hypothesis A. dhakensis with varied geographic prevalence and enhanced virulence that compared to other Aeromonas species warrants more investigations.

  2. Aeromonas hydrophila infection in Xenopus laevis.

    Science.gov (United States)

    Hubbard, G B

    1981-06-01

    Aeromonas hydrophila caused severe disease in a group of Xenopus laevis within 3 weeks of receipt. The primary clinical signs were marked pallor of the skin, petechiation, lethargy, anorexia, and edema. The duration of the outbreak was approximately 45 days during which time 21 frogs became sick and 18 died, despite tetracycline therapy. Pale skin, subcutaneous edema and hemorrhages, ascites, and pale livers were seen at necropsy. Aeromonas hydrophila was isolated from skin, and the same organism was isolated in pure culture from skeletal muscle. Tetracycline treatment via stomach tube was effective if given early in the course of the disease. The outbreak was controlled by removing sick frogs, feeding twice per week, changing the water several hours after feeding, and maintaining the frogs where the ambient temperature was 22 degrees C or lower. The pallor of the skin and general malaise were produced experimentally by crowding normal frogs, changing the water infrequently, and increasing ambient temperatures. Mild disease was reproduced experimentally by subcutaneous injection of Aeromonas hydrophila into apparently healthy frogs.

  3. Aeromonas in Arab countries: 1995-2014.

    Science.gov (United States)

    Ghenghesh, Khalifa Sifaw; Rahouma, Amal; Zorgani, Abdulaziz; Tawil, Khaled; Al Tomi, Abdurazzaq; Franka, Ezzadin

    2015-10-01

    The aim of this review is to provide information on the prevalence, clinical syndromes, and antimicrobial resistance and therapy of Aeromonas spp. infections in Arab countries. The data were obtained by an English language literature search from 1995 to 2014 of Medline and PubMed for papers using the search terms "Aeromonas+name of Arab country (i.e. Algeria, Egypt, etc.)". Additional data were obtained from a Google search using the aforementioned terms. The organisms have been reported from diarrheal children, patients with cholera-like diarrhea, an outbreak of acute gastroenteritis and from different types of animals, foods and water source in several Arab countries in the Middle East and North Africa with predominance of A. hydrophila, A. caviae and A. sobria. Using molecular techniques few studies reported genes encoding several toxins from aeromonads isolated from different sources. Among the antimicrobials examined in the present review third generation cephalosporins, fluoroquinolones and aminoglycosides showed excellent activity and can be employed in the treatment of Aeromonas-associated human infections in Arabic countries. Whenever possible, treatment should be guided by the susceptibility testing results of the isolated organism. In the future, studies employing molecular testing methods are required to provide data on circulating genospecies and their modes of transmission in the community, and on their mechanisms of resistance to antimicrobials. Microbiology laboratories and research centers are encouraged to look for these organisms in clinical, food and water sources to attain a better understanding of the public health risks from these organisms in Arab countries.

  4. Incidence and virulence characteristics of Aeromonas spp. in fish

    Directory of Open Access Journals (Sweden)

    Ashraf M. Abd-El-Malek

    2017-01-01

    Full Text Available Aim: This study was conducted to evaluate the presence of Aeromonas spp. in raw and ready-to-eat (RTE fish commonly consumed in Assiut city, Egypt, and to determine virulence factors due to they play a key role in their pathogenicity. Materials and Methods: A total of 125 samples of raw and RTE fish samples were taken from different fish markets and fish restaurants in Assiut Governorate and screened for the presence of Aeromonas spp. by enrichment on tryptic soy broth then incubated at 30°C for 24 h. Plating unto the sterile Petri dishes containing Aeromonas agar base to which Aeromonas selective supplement was added. The plates were incubated at 37°C for 24 h. Presumptive Aeromonas colonies were biochemically confirmed and analyzed for pathogenicity by hemolysin production, protease, and lipase detection. Results: The results indicated that raw fish were contaminated with Aeromonas spp. (40% in wild and 36% in cultured Nile tilapia. Regarding RTE, Aeromonas spp. could be isolated with the percentage of 16%, 28% and 20% in fried Bolti, grilled Bolti and fried Bayad, respectively. Out of 35 isolates obtained, 22 were categorized as Aeromonas hydrophila, 12 were classified as Aeromonas sobria and Aeromonas caviae were found in only one isolate. The virulence factors of Aeromonas spp. were detected and the results showed that all isolates produced of hemolysin (91.4%, protease (77.1%, and lipase enzyme (17.1%. Conclusion: This study indicates that the presence of A. hydrophila with virulence potential in fresh and RTE fish may be a major threat to public health.

  5. Aeromonas aquatica sp. nov., Aeromonas finlandiensis sp. nov. and Aeromonas lacus sp. nov. isolated from Finnish waters associated with cyanobacterial blooms.

    Science.gov (United States)

    Beaz-Hidalgo, R; Latif-Eugenín, F; Hossain, M J; Berg, K; Niemi, R M; Rapala, J; Lyra, C; Liles, M R; Figueras, M J

    2015-05-01

    Three groups of Aeromonas strains isolated from Finland lakes experiencing cyanobacterial blooms could not be assigned to any known species of this genus on the basis of 16S rRNA and rpoD gene sequences. The Multilocus Phylogenetic Analysis (MLPA) of the concatenated sequence of seven genes (gyrB, rpoD, recA, dnaJ, gyrA, dnaX and atpD; 4093bp) showed that the three groups of strains did not cluster with any known Aeromonas spp. and formed three independent lineages. This was confirmed by performing the analysis with their closest relatives using 15 genes (the latter 7 and cpn60, dnaK, gltA, mdh, radA, rpoB, tsf, zipA; 8751bp). Furthermore, ANI results between the genomes of the type strains of the three potential new species and those of their close relatives were all Aeromonas species on the basis of several phenotypic characters. This polyphasic study revealed that the 3 groups of strains represent 3 novel Aeromonas species for which the names Aeromonas aquatica sp. nov. (type strain AE235T=CECT 8025T=LMG 26712T), Aeromonas finlandiensis sp. nov. (type strain 4287DT=CECT 8028T=LMG 26709T) and Aeromonas lacus sp. nov. (type strain AE122T=CECT 8024T=LMG 26710T) are proposed.

  6. Isolation and antibiotic sensitivity of Aeromonas from children with diarrhea

    Directory of Open Access Journals (Sweden)

    Meiyanti Meiyanti

    2016-02-01

    Full Text Available Aeromonas species are gram-negative, motile, facultative anaerobic, rod shaped, oxidase positive bacteria of the recently assigned family Aeromonadaceae. The significance of Aeromonas species as causative agent of human diarrhoea has recently been established. The aim of the present study was to investigate the distribution, and antibiotic sensitivity of Aeromonas in nonhospitalized children with diarrhea.One hundred and seventeen rectal swabs from children with diarhhea were cultured for isolation of Aeromonas organisms as the etiological agents. In addition to Aeromonas, other enteric pathogens were also isolated. Overall, the isolates of enteric pathogens amounted to 36.8%, consisting of Salmonella, Shigella, Aeromonas, and Vibrio. Aeromonas was only found in 5.1% of cultures, with a ratio of A. caviae and A. hydrophila of 2:1, while Salmonella made up the majority of causative organisms with an isolation frequency of 18.8%, followed by Shigella with 11.1%. In this study no isolates of Vibrio cholerae O1 were found as etiological agents of diarrhea; however, V. cholerae non-O1 and V. parahaemolyticus were found in small numbers (<1%. All isolates of Aeromonas were resistant to ampicillin and tetracycline, but sensitive to ciprofloxacin and ceftriaxone, as were the other enteric pathogens. Although the frequency of isolation of these enteric pathogens was higher than for Vibrio spp., their role in infective diarrhea was less clearcut in comparison with Salmonella and Shigella.

  7. Complete genome sequence of Aeromonas hydrophila AL06-06

    Science.gov (United States)

    Aeromonas hydrophila occurs in freshwater environments and infects fish and mammals. In this work, we report the complete genome sequence of Aeromonas hydrophila AL06-06, which was isolated from diseased goldfish and is being used for comparative genomic studies with A. hydrophila strains causing ba...

  8. Draft genome sequence of Aeromonas hydrophila TN97-08

    Science.gov (United States)

    Aeromonas hydrophila is an opportunistic Gram-negative species causing disease in fish and mammals. The genus Aeromonas affects a variety of aquatic organisms and lives in diverse aquatic ecosystems (1). There are 39 A. hydrophila genomes currently available in GenBank. In the current study, we repo...

  9. OVERVIEW: DISINFECTION OF HELICOBACTER PYLORI AND AEROMONAS SPECIES

    Science.gov (United States)

    Helicobacter pylori and Aeromonas hydrophila are contaminants listed on the USEPA's 1998 Contaminant Candidate List (CCL).The sensitivity of H. pylori to chlorine and of Aeromonas spp. to inactivation by free chlorine, chloramine and ultraviolet (UV) was examined. Selective and...

  10. CHARACTERIZATION OF AEROMONAS VIRULENCE USING AN IMMUNOCOMPROMISED MOUSE MODEL

    Science.gov (United States)

    An immunocompromised mouse model was used to characterize Aeromonas strains for their ability to cause opportunistic, extraintestinal infections. A total of 34 isolates of Aeromonas (A. hydrophila [n = 12]), A. veronii biotype sobria [n = 7], A. caviae [n = 4], A. enchelia [n = 4...

  11. Chitin degradation and metabolism by virulent Aeromonas hydropila

    Science.gov (United States)

    Aeromonas hydrophila is the causal agent of motile Aeromonas septicemia (MAS) in catfish and other warm-water fishes. Severe outbreak of MAS caused by virulent A. hydrophila (vAh) was reported in 2009 in the Southeastern United States; the disease has since resulted in loss of millions of pounds of ...

  12. Comparative in vitro activities of selected antimicrobial agents against Aeromonas species and Plesiomonas shigelloides.

    OpenAIRE

    1985-01-01

    The in vitro antimicrobial susceptibilities of fecal isolates of Aeromonas caviae, Aeromonas hydrophila, Aeromonas sobria, and Plesiomonas shigelloides were tested by agar dilution. This in vitro study suggested that ciprofloxacin, enoxacin, norfloxacin, tetracycline, and trimethoprim-sulfamethoxazole might be effective oral agents for treatment of diarrhea involving Aeromonas spp. or P. shigelloides.

  13. NCBI nr-aa BLAST: CBRC-CREM-01-1309 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CREM-01-1309 ref|YP_001140721.1| membrane protein [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO88973.1| membrane protein [Aeromonas salmonicida subsp. salmonicida A449] YP_001140721.1 9e-50 46% ...

  14. NCBI nr-aa BLAST: CBRC-DSIM-02-0033 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DSIM-02-0033 ref|YP_001141368.1| regulator of uhpT [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO89620.1| regulator of uhpT [Aeromonas salmonicida subsp. salmonicida A449] YP_001141368.1 3.1 20% ...

  15. NCBI nr-aa BLAST: CBRC-VPAC-01-0406 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-VPAC-01-0406 ref|YP_001141292.1| O-antigen acetylase [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO89544.1| O-antigen acetylase [Aeromonas salmonicida subsp. salmonicida A449] YP_001141292.1 2.1 28% ...

  16. NCBI nr-aa BLAST: CBRC-AGAM-07-0002 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0002 ref|YP_001142445.1| membrane protein [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO90697.1| membrane protein [Aeromonas salmonicida subsp. salmonicida A449] YP_001142445.1 1e-130 93% ...

  17. NCBI nr-aa BLAST: CBRC-AGAM-07-0060 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0060 ref|YP_001142002.1| GGDEF domain protein [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO90254.1| GGDEF domain protein [Aeromonas salmonicida subsp. salmonicida A449] YP_001142002.1 6e-21 30% ...

  18. NCBI nr-aa BLAST: CBRC-DSIM-04-0091 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DSIM-04-0091 ref|YP_001143655.1| imidazolonepropionase [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO91907.1| imidazolonepropionase [Aeromonas salmonicida subsp. salmonicida A449] YP_001143655.1 0.71 22% ...

  19. NCBI nr-aa BLAST: CBRC-AGAM-07-0010 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0010 ref|YP_001141362.1| amino acid permease [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO89614.1| amino acid permease [Aeromonas salmonicida subsp. salmonicida A449] YP_001141362.1 1e-132 96% ...

  20. NCBI nr-aa BLAST: CBRC-OLAT-18-0005 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OLAT-18-0005 ref|YP_001142445.1| membrane protein [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO90697.1| membrane protein [Aeromonas salmonicida subsp. salmonicida A449] YP_001142445.1 0.001 25% ...

  1. NCBI nr-aa BLAST: CBRC-AGAM-07-0022 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0022 ref|YP_001140043.1| O-antigen ligase [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO88295.1| O-antigen ligase [Aeromonas salmonicida subsp. salmonicida A449] YP_001140043.1 1e-145 76% ...

  2. NCBI nr-aa BLAST: CBRC-AGAM-07-0021 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0021 ref|YP_001140588.1| Na+/H antiporter NhaA [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO88840.1| Na+/H antiporter NhaA [Aeromonas salmonicida subsp. salmonicida A449] YP_001140588.1 1e-123 94% ...

  3. NCBI nr-aa BLAST: CBRC-AGAM-01-0054 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-01-0054 ref|YP_001142086.1| transporter, NadC family [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO90338.1| transporter, NadC family [Aeromonas salmonicida subsp. salmonicida A449] YP_001142086.1 0.76 25% ...

  4. NCBI nr-aa BLAST: CBRC-AGAM-07-0064 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0064 ref|YP_001143407.1| sulfatase [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO91659.1| sulfatase [Aeromonas salmonicida subsp. salmonicida A449] YP_001143407.1 0.0 87% ...

  5. NCBI nr-aa BLAST: CBRC-AGAM-07-0060 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-AGAM-07-0060 ref|YP_001141367.1| GGDEF domain protein [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO89619.1| GGDEF domain protein [Aeromonas salmonicida subsp. salmonicida A449] YP_001141367.1 1e-165 88% ...

  6. NCBI nr-aa BLAST: CBRC-XTRO-01-0311 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0311 ref|YP_001141455.1| membrane protein [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO89707.1| membrane protein [Aeromonas salmonicida subsp. salmonicida A449] YP_001141455.1 4e-21 40% ...

  7. NCBI nr-aa BLAST: CBRC-CREM-01-1283 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CREM-01-1283 ref|YP_001143262.1| sodium/proline symporter [Aeromonas salmonicida subsp. salmon...icida A449] gb|ABO91514.1| sodium/proline symporter [Aeromonas salmonicida subsp. salmonicida A449] YP_001143262.1 1e-71 67% ...

  8. Isolation of Aeromonas spp. from Food Products: Emerging Aeromonas Infections and Their Significance in Public Health.

    Science.gov (United States)

    Alhazmi, Mohammad Ismail

    2015-01-01

    Aeromonas spp. are opportunistic pathogens causing a broad spectrum of human illnesses like gastroenteritis, chronic diarrhea, wound infections, peritonitis, urinary tract infections, and septicemia. Their ability to grow in foods stored in a refrigerator poses a substantial threat for human consumption. We investigated the prevalence of Aeromonas from commercial food products across Riyadh, Saudi Arabia. A total of 250 samples were randomly collected and processed for the isolation and identification of Aeromonas by morphological and biochemical means and for their identification by PCR. A total of 102 strains of Aeromonas were isolated, including 47% from raw meat samples, 34% from raw fish samples, and 18.6% from milk and dairy products; 56.8% were identified as A. hydrophila and 43.1% as A. sobria. Antibiotic susceptibility tests done revealed 100% sensitivity to chloramphenicol, colistin, ciprofloxacin, and nitrofurantoin. 16S rDNA PCR revealed the presence of the 953 bp fragment in all the strains. The present investigation suggested the occurrences of A. sobria and A. hydrophila in human consumable stored and refrigerated foods.

  9. Chironomid egg masses harbour the clinical species Aeromonas taiwanensis and Aeromonas sanarellii.

    Science.gov (United States)

    Beaz-Hidalgo, Roxana; Shakèd, Tamar; Laviad, Sivan; Halpern, Malka; Figueras, María J

    2012-12-01

    Bacteria of the genus Aeromonas are found worldwide in aquatic environments and may produce human infections. In 2010, two new clinical species, Aeromonas sanarellii and Aeromonas taiwanensis, were described on the basis of one strain recovered from wounds of hospitalized patients in Taiwan. So far, only four environmental isolates of A. sanarellii and one of A. taiwanensis have been recorded from waste water in Portugal and an additional clinical strain of A. taiwanensis from the faeces of a patient with diarrhoea in Israel. In the present study, strains belonging to these two species were identified from chironomid egg masses from the same area in Israel by sequencing the rpoD gene. This represents a new environmental habitat for these novel species. The first data on the virulence genes and antibiotic susceptibility are provided. The isolates of these two new species possess multiple virulence genes and are sensitive to amikacin, aztreonam, cefepime, cefoxatime, ceftazidime, ciprofloxacin, gentamicin, piperacillin-tazobactam, tigecycline, tobramycin, trimethoprim-sulfamethoxazole and imipenem. The key phenotypic tests for the differentiation of these new species from their closest relative Aeromonas caviae included the utilization of citrate, growth at 45 °C in sheep blood agar and acid production of cellobiose.

  10. Reassessment of the Enteropathogenicity of Mesophilic Aeromonas Species

    Science.gov (United States)

    Teunis, Peter; Figueras, Maria J.

    2016-01-01

    Cases of Aeromonas diarrhea have been described all over the world. The genus Aeromonas includes ca. 30 species, of which 10 have been isolated in association with gastroenteritis. The dominating species that account for ca. 96% of the identified strains are Aeromonas caviae, A. veronii, A. dhakensis, and A. hydrophila. However, the role of Aeromonas as a true enteropathogen has been questioned on the basis of the lack of outbreaks, the non-fulfillment of Koch’s postulates and the low numbers of acute illnesses in the only existing human challenge study. In the present study we reassess the enteropathogenicity of Aeromonas using dose response models for microbial infection and acute illness. The analysis uses the data from the human challenge study and additional data from selected outbreak investigations where the numbers exposed and the dose were reported, allowing their inclusion as “natural experiments”. In the challenge study several cases of asymptomatic shedding were found (26.3%, 15/57), however, only 3.5% (2/57) of those challenged with Aeromonas developed acute enteric symptoms (i.e., diarrhea). The “natural experiments” showed a much higher risk of illness associated with exposure to Aeromonas, even at moderate to low doses. The median dose required for 1% illness risk, was ~1.4 × 104 times higher in the challenge study (1.24 × 104 cfu) compared to natural exposure events (0.9 cfu). The dose response assessment presented in this study shows that the combined challenge and outbreak data are consistent with high infectivity of Aeromonas, and a wide range of susceptibility to acute enteric illness. To illustrate the outcomes, we simulate the risk associated with concentrations of Aeromonas found in different water and food matrices, indicating the disease burden potentially associated with these bacteria. In conclusion this study showed that Aeromonas is highly infectious, and that human susceptibility to illness may be high, similar to

  11. Characterization of isolates of Flavobacterium psychrophilum associated with coldwater disease or rainbow trout fry syndrome II: serological studies

    DEFF Research Database (Denmark)

    Lorenzen, Ellen; Olesen, Niels Jørgen

    1997-01-01

    The possibility of seroIogical differentiation between isolates of Flavobacterium psychrophilum was analyzed by ELISA and slide agglutination. Twenty-five Danish isolates and 20 isolates from other European countries were studied using polyclonal rabbit antisera and whole-cell preparations...... species with different disease signs, The ELISA showed the existence of different serotypes most distinctly, but slide agglutination supported the ELISA results. Three serotypes were found among the isolates studied: 1 major serotype (serotype Th) represented most of the Danish isolates and isolates from...

  12. Insight into the mobilome of Aeromonas strains

    Directory of Open Access Journals (Sweden)

    Marta ePiotrowska

    2015-05-01

    Full Text Available The mobilome is a pool of genes located within mobile genetic elements (MGE, such as plasmids, IS elements, transposons, genomic/pathogenicity islands, and integron-associated gene cassettes. These genes are often referred to as flexible and may encode virulence factors, toxic compounds as well as resistance to antibiotics. The phenomenon of MGE transfer between bacteria, known as horizontal gene transfer (HGT, is well documented. The genes present on MGE are subject to continuous processes of evolution and environmental changes, largely induced or significantly accelerated by man. For bacteria, the only chance of survival in an environment contaminated with toxic chemicals, heavy metals and antibiotics is the acquisition of genes providing the ability to survive in such conditions. The process of acquiring and spreading antibiotic resistance genes (ARG is of particular significance, as it is important for the health of humans and animals. Therefore, it is important to thoroughly study the mobilome of Aeromonas spp. that is widely distributed in various environments, causing many diseases in fishes and humans. This review discusses the recently published information on MGE prevalent in Aeromonas spp. with special emphasis on plasmids belonging to different incompatibility groups, i.e., IncA/C, IncU, IncQ, IncF, IncI and ColE-type. The vast majority of plasmids carry a number of different transposons (Tn3, Tn21, Tn1213, Tn1721, Tn4401, the 1st, 2nd or 3rd class of integrons, IS elements (e.g. IS26, ISPa12, ISPa13, ISKpn8, ISKpn6 and encode determinants such as antibiotic and mercury resistance genes, as well as virulence factors. Although the actual role of Aeromonas spp. as a human pathogen remains controversial, species of this genus may pose a serious risk to human health. This is due to the considerable potential of their mobilome, particularly in terms of antibiotic resistance and the possibility of the horizontal transfer of resistance

  13. Diversity and Geographical Distribution of Flavobacterium psychrophilum Isolates and Their Phages: Patterns of Susceptibility to Phage Infection and Phage Host Range

    DEFF Research Database (Denmark)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Espejo, Romilio

    2014-01-01

    Flavobacterium psychrophilum is an important fish pathogen worldwide that causes cold water disease (CWD) or rainbow trout fry syndrome (RTFS). Phage therapy has been suggested as an alternative method for the control of this pathogen in aquaculture. However, effective use of bacteriophages in di...

  14. The immune response of rainbow trout to Flavobacterium psychrophilum following immersion-challenge model with and without hydrogen peroxide pre-treatment

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi; Madsen, Lone; Kania, P. W.;

    2013-01-01

    , no commercial vaccine is currently available and the disease is treated with antibiotics. Injection-based challenges with F. psychrophilum are standardized but the route of infection does not reflect a natural situation. Therefore, we established an immersion-based model investigating if hydrogen peroxide (H2O2...

  15. Evaluation of the immune response in rainbow trout fry, Oncorhynchus mykiss (Walbaum), after waterborne exposure to Flavobacterium psychrophilum and/or hydrogen peroxide

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi; Kania, P. W.; Buchmann, Kurt;

    2015-01-01

    The immune response in rainbow trout fry against Flavobacterium psychrophilum was elucidated using an immersion-based challenge with or without prior exposure to hydrogen peroxide (H2O2). Samples were taken from the head kidney 4, 48, 125 and 192 h after immersion, and the regulation of several...

  16. Proinflammatory cytokine and cytokine receptor gene expression kinetics following challenge with Flavobacterium psychrophilum in resistant and susceptible lines of rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Flavobacterium psychrophilum (Fp) is the causative agent of bacterial cold water disease (BCWD) which causes appreciable economic losses in rainbow trout aquaculture. We previously reported development of a genetic line, designated ARS-Fp-R that exhibits higher survival relative to a susceptible lin...

  17. Differential expression of long non-coding RNAs in three genetic lines of rainbow trout (Oncorhynchus mykiss) in response to infection with Flavobacterium psychrophilum

    Science.gov (United States)

    Bacterial cold-water disease caused by Flavobacterium psychrophilum is one of the major causes of mortality of salmonids. Three genetic lines of rainbow trout designated as ARS-Fp-R (resistant), ARS-Fp-C (control) and ARS-Fp-S (susceptible) have significant differences in survival rate following F. ...

  18. Diversity and geographical distribution of Flavobacterium psychrophilum isolates and their phages: patterns of susceptibility to phage infection and phage host range.

    Science.gov (United States)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Espejo, Romilio; Middelboe, Mathias

    2014-05-01

    Flavobacterium psychrophilum is an important fish pathogen worldwide that causes cold water disease (CWD) or rainbow trout fry syndrome (RTFS). Phage therapy has been suggested as an alternative method for the control of this pathogen in aquaculture. However, effective use of bacteriophages in disease control requires detailed knowledge about the diversity and dynamics of host susceptibility to phage infection. For this reason, we examined the genetic diversity of 49 F. psychrophilum strains isolated in three different areas (Chile, Denmark, and USA) through direct genome restriction enzyme analysis (DGREA) and their susceptibility to 33 bacteriophages isolated in Chile and Denmark, thus covering large geographical (>12,000 km) and temporal (>60 years) scales of isolation. An additional 40 phage-resistant isolates obtained from culture experiments after exposure to specific phages were examined for changes in phage susceptibility against the 33 phages. The F. psychrophilum and phage populations isolated from Chile and Denmark clustered into geographically distinct groups with respect to DGREA profile and host range, respectively. However, cross infection between Chilean phage isolates and Danish host isolates and vice versa was observed. Development of resistance to certain bacteriophages led to susceptibility to other phages suggesting that "enhanced infection" is potentially an important cost of resistance in F. psychrophilum, possibly contributing to the observed co-existence of phage-sensitive F. psychrophilum strains and lytic phages across local and global scales. Overall, our results showed that despite the identification of local communities of phages and hosts, some key properties determining phage infection patterns seem to be globally distributed.

  19. Improved husbandry to control an outbreak of rainbow trout fry syndrome caused by infection with Flavobacterium psychrophilum

    Science.gov (United States)

    Bebak, J.A.; Welch, T.J.; Starliper, C.E.; Baya, A.M.; Garner, M.M.

    2007-01-01

    Case Description - A cohort of 35,200, 13-week-old, female rainbow trout at a fish farm was evaluated because of a 2-week history of anorexia and lethargy and a mortality rate of approximately 100 fish/d. Clinical Findings - Affected fish were lethargic and thin and had disequilibrium, bilateral exophthalmia, pale red gills and kidneys, red-tinged coelomic fluid, and pale brown livers. Some fish were differentially pigmented bilaterally. The presumptive diagnosis was bacterial or viral septicemia. The definitive diagnosis was rainbow trout fry syndrome caused by infection with Flavobacterium psychrophilum. Treatment and Outcome - A strategy for controlling the outbreak based on reducing pathogen numbers in affected tanks and reducing pathogen spread among tanks was developed. The option of treating with antimicrobial-medicated feed was discussed with the farmer, but was declined. After changes were made, mortality rate declined quickly, with no more deaths within 10 days after the initial farm visit. Clinical Relevance - Bacterial coldwater disease is the most common manifestation of infection with F psychrophilum in fingerling and adult rainbow trout. However, the organism can also cause rainbow trout fry syndrome. This condition should be included on a list of differential diagnoses for septicemia in hatchery-reared rainbow trout fry.

  20. Protection against Flavobacterium psychrophilum infection (cold water disease) in Ayu fish (Plecoglossus altivelis) by oral administration of humus extract.

    Science.gov (United States)

    NAKAGAWA, Jun; IWASAKI, Tadashi; KODAMA, Hiroshi

    2009-11-01

    Humic substances are formed during the decomposition of organic matter in humus, and are found in many natural environments in which organic materials and microorganisms have been present. In the present study, oral administration of humus extract to ayu fish (Plecoglossus altivelis) induced effective protection against experimental Flavobacterium psychrophilum infection (cold water disease). Mortality of fish and development of skin lesions, such as erosion and hemorrhages on the skin, gill cover or mouth, were significantly suppressed in fish treated with 10%, 5% or 1% humus extract adsorbed on dry pellets. Although F. psychrophilum was not re-isolated from gills and erosion lesions of the skin of dead fish, bacterial gyrB DNA could be amplified in these specimens from dead fish and surviving control fish using the polymerase chain reaction. The protective effect of the extract was not the results of direct killing of bacteria or antibiotic activity of the extract since no obvious reduction in the bacterial number was observed at 5 times to 5,000 times dilution of the humus extract having pH 5.45 to 7.40. These results clearly show that treating fish with humus extract is effective in preventing cold water disease.

  1. Differential media for quantitative recovery of waterborne Aeromonas hydrophila.

    Science.gov (United States)

    Handfield, M; Simard, P; Letarte, R

    1996-09-01

    Because of the ubiquity of Aeromonas spp., their prevalence in drinking water, and the increasing number of reports on Aeromonas sp.-related infections, a standard method for routine and quantitative recovery had to be defined. On the basis of a survey of 10 media for recovery analysis and subsequent differentiation assays in mixed cultures, we conclude that ampicillin-dextrin agar performed the best for the recovery of Aeromonas spp. in drinking water and the differentiation by simple criteria of that genus from other common waterborne bacteria.

  2. Studies concerning the antigen affinities of Aeromonas punctata strains

    National Research Council Canada - National Science Library

    Krug, S

    1982-01-01

    On the basis of 90 determined Aeromonas punctata strains from different fish species serological cross reactions were carried out with the aid of agglutination and precipitation to determine antigen...

  3. Post-traumatic osteomyelitis due to aeromonas species

    Directory of Open Access Journals (Sweden)

    Gunasekaran L

    2009-01-01

    Full Text Available We report a case of Aeromonas osteomyelitis due to injury in a sewage worker. He presented with cellulitis of the left foot. Radiographs showed evidence of osteomyelitis involving the head and neck of the fifth metatarsal. Aeromonas species was isolated from the tissue and swab from the foot. The head and neck of the fifth metatarsal were excised and the patient improved on 4 weeks of intravenous meropenem followed by 4 weeks of oral clindamycin and ciprofloxacin.

  4. Emerging Aeromonas Species Infections and Their Significance in Public Health

    OpenAIRE

    Igbinosa, Isoken H.; Ehimario U. Igumbor; Farhad Aghdasi; Mvuyo Tom; Anthony I. Okoh

    2012-01-01

    Aeromonas species are ubiquitous bacteria in terrestrial and aquatic milieus. They are becoming renowned as enteric pathogens of serious public health concern as they acquire a number of virulence determinants that are linked with human diseases, such as gastroenteritis, soft-tissue, muscle infections, septicemia, and skin diseases. Proper sanitary procedures are essential in the prevention of the spread of Aeromonas infections. Oral fluid electrolyte substitution is employed in the preventio...

  5. Pneumonia caused by Aeromonas species in Taiwan, 2004-2011.

    Science.gov (United States)

    Chao, C M; Lai, C C; Tsai, H Y; Wu, C J; Tang, H J; Ko, W C; Hsueh, P-R

    2013-08-01

    We investigated the clinical characteristics of patients with pneumonia caused by Aeromonas species. Patients with pneumonia caused by Aeromonas species during the period 2004 to 2011 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed. Of the 84 patients with pneumonia due to Aeromonas species, possible Aeromonas pneumonia was diagnosed in 58 patients, probable Aeromonas pneumonia was diagnosed in 18 patients, and pneumonia due to Aeromonas was conclusively diagnosed in 8 patients. Most of the cases of Aeromonas pneumonia developed in men and in patients of advanced age. A. hydrophila (n = 50, 59.5 %) was the most common pathogen, followed by A. caviae (n = 24, 28.6 %), A. veronii biovar sobria (n = 7, 8.3 %), and A. veronii biovar veronii (n = 3, 3.6 %). Cancer (n = 37, 44.0 %) was the most common underlying disease, followed by diabetes mellitus (n = 27, 32.1 %). Drowning-associated pneumonia developed in 6 (7.1 %) patients. Of 47 patients who were admitted to the intensive care ward, 42 patients developed acute respiratory failure and 24 of those patients died. The overall in-hospital mortality rate was significantly associated with liver cirrhosis, cancer, initial presentation of shock, and usage of mechanical ventilation. In conclusion, Aeromonas species should be considered as one of the causative pathogens of severe pneumonia, especially in immunocompromised patients, and should be recognized as a cause of drowning-associated pneumonia. Cirrhosis, cancer, and shock as the initial presenting symptom are associated with poor outcome.

  6. Skin and soft-tissue infections caused by Aeromonas species.

    Science.gov (United States)

    Chao, C M; Lai, C C; Tang, H J; Ko, W C; Hsueh, P-R

    2013-04-01

    This study investigated the clinical characteristics of patients with skin and soft-tissue infections (SSTIs) due to Aeromonas species. Patients with SSTIs caused by Aeromonas species during the period from January 2009 to December 2011 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed. A total of 129 patients with SSTIs due to Aeromonas species were identified. A. hydrophila (n = 77, 59.7 %) was the most common pathogen, followed by A. veronii biovar sobria (n = 22, 17.1 %), A. veronii biovar veronii (n = 20, 15.5 %), A. caviae (n = 9, 7.0 %), and A. schubertii (n = 1, 0.8 %). The most common isolates obtained from patients with polymicrobial infections were Klebsiella species (n = 33), followed by Enterococcus spp. (n = 24), Enterobacter spp. (n = 21), Escherichia coli (n = 17), Staphylococcus spp. (n = 17), Streptococcus spp. (n = 17), and Acinetobacter spp. (n = 15). Liver cirrhosis and concomitant bacteremia were more common among patients with monomicrobial Aeromonas SSTIs than among patients with polymicrobial SSTIs. Nine (7 %) patients required limb amputations. The in-hospital mortality rate was 1.6 %. In conclusion, Aeromonas species should be considered as important causative pathogens of SSTIs, and most infections are polymicrobial. In addition, the clinical presentation differs markedly between patients with monomicrobial and those with polymicrobial Aeromonas SSTIs.

  7. Aeromonas hydrophila Sepsis Mimicking Vibrio vulnificus Infection.

    Science.gov (United States)

    Park, Se Young; Nam, Hyun Min; Park, Kun; Park, Seok Don

    2011-09-01

    Aeromonas hydrophila is a facultatively anaerobic, asporogenous gram-negative rod that has often been regarded as an opportunistic pathogen in hosts with impairment of a local or general defense mechanism. A 68-year-old alcoholic woman presented with shock and gangrene on the right arm. At first, her clinical presentations were severe painful erythematous swelling that worsened within a few hours with development of gangrene, edema, and blisters. Bullous fluid and blood cultures yielded A. hydrophila. Histopathological findings of sections obtained from the vesicle revealed subepidermal vesicles; necrosis of the epidermis, papillary dermis, and subcutaneous fat; and massive hemorrhage in the subcutis. Despite all efforts to save the patient, she died 8 hours after admission. Clinical features of A. hydrophila sepsis resemble those of Vibrio vulnificus sepsis. Therefore, in addition to the case report, we compared the cultural, biochemical, and morphological differences between A. hydrophila and V. vulnificus for facilitation of early and accurate identification of the causative agent.

  8. Peritonitis bacteriana espontánea y bacteriemia por Aeromonas hydrophila Spontaneous bacterial peritonitis and bacteraemia due to Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    J. J. García-Irure

    2003-12-01

    Full Text Available La peritonitis bacteriana es una complicación frecuente en los pacientes cirróticos. De los gérmenes etiológicos, Aeromonas es muy poco frecuente. Presentamos un caso clínico de un paciente cirrótico con peritonitis y bacteriemia por Aeromonas hydrophila. Este microorganismo es un bacilo gramnegativo de la familia Vibrionaceae. En el ser humano produce gastroenteritis con mucha frecuencia. De forma excepcional puede dar origen a infecciones extraintestinales, sobre todo en pacientes inmunodeprimidos. La peritonitis por Aeromonas se ha descrito en asociación a peritonitis bacteriana espontánea en pacientes cirróticos, en pacientes en diálisis peritoneal y en casos de peritonitis secundaria a perforación intestinal.Bacterial peritonitis is a frequent complication in cirrhotic patients. Amongst the aetiological germs, Aeromonas is very infrequent. We present the clinical case of a cirrhotic patient with peritonitis and bacteraemia due to Aeromonas hydrophila. This micro-organism is a Gram-negative bacillus of the Vibrionaceae family. It very frequently produces gastroenteritis in the human being. Exceptionally it can give rise to extraintestinal infections, especially in immunodepressed patients. Peritonitis due to Aeromonas has been described in association with spontaneous bacterial peritonitis in cirrhotic patients, in patients on peritoneal dialysis and in cases of peritonitis secondary to intestinal perforation.

  9. Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulon

    Directory of Open Access Journals (Sweden)

    Sunniva Katharina Thode

    2017-07-01

    Full Text Available Background The ferric uptake regulator (Fur is a transcription factor and the main regulator of iron acquisition in prokaryotes. When bound to ferric iron, Fur recognizes its DNA binding site and generally executes its function by repressing transcription of its target genes. Due to its importance in virulence, the Fur regulon is well studied for several model bacteria. In our previous work, we used computational predictions and microarray to gain insights into Fur-regulation in Aliivibrio salmonicida, and have identified a number of genes and operons that appear to be under direct control of Fur. To provide a more accurate and deeper global understanding of the biological role of Fur we have now generated an A. salmonicida fur knock-out strain and used RNA-sequencing to compare gene expression between the wild-type and fur null mutant strains. Results An A. salmonicida fur null mutant strain was constructed. Biological assays demonstrate that deletion of fur results in loss of fitness, with reduced growth rates, and reduced abilities to withstand low-iron conditions, and oxidative stress. When comparing expression levels in the wild-type and the fur null mutant we retrieved 296 differentially expressed genes distributed among 18 of 21 functional classes of genes. A gene cluster encoding biosynthesis of the siderophore bisucaberin represented the highest up-regulated genes in the fur null mutant. Other highly up-regulated genes all encode proteins important for iron acquisition. Potential targets for the RyhB sRNA was predicted from the list of down-regulated genes, and significant complementarities were found between RyhB and mRNAs of the fur, sodB, cysN and VSAL_I0422 genes. Other sRNAs with potential functions in iron homeostasis were identified. Conclusion The present work provides by far the most comprehensive and deepest understanding of the Fur regulon in A. salmonicida to date. Our data also contribute to a better understanding of how

  10. Aeromonas caviae strain induces Th1 cytokine response in mouse intestinal tract

    Science.gov (United States)

    Aeromonas caviae has been associated with human gastrointestinal disease. Strains of this species typically lack virulence factors (VFs) such as enterotoxins and hemolysins that are produced by other human pathogens of the Aeromonas genus,. Microarray profiling of...

  11. Interlaboratorium vergelijking van het onderzoek naar Aeromonas spp. in drinkwater (tweede onderzoek)

    NARCIS (Netherlands)

    Versteegh JFM; During M; Heisterkamp SH; Havelaar AH

    1988-01-01

    Door middel van kwantitatief onderzoek naar Aeromonas-bacterien in drie verschillende monsters water (De Bilt, De Meent en De Laak) werd een vergelijking gemaakt van de resultaten van Aeromonas onderzoek in 15 laboratoria in het kader van het deelproject: "Aeromonas in drinkwater". Varian

  12. MONITORING THE EFFECTIVENESS OF UV DISINFECTION OF AEROMONAS SPP. USING SELECTIVE AND NON-SELECTIVE MEDIA

    Science.gov (United States)

    This research was initiated to determine the sensitivity of Aeromonas spp. to ultraviolet (UV) disinfection. Aeromonas hydrophila is a contaminant listed on the USEPA's 1998 CCL. Three different Aeromonas spp. (A. hydrophila, A. sobria and A. caviae) were tested using membrane fi...

  13. Detection and quantification of Flavobacterium psychrophilum specific bacteriophages in rainbow trout upon different administration methods: Implications for disease control in aquaculture

    DEFF Research Database (Denmark)

    Christiansen, Rói Hammershaimb; Madsen, Lone; Dalsgaard, Inger

    2013-01-01

    Flavobacterium psychrophilum is the pathogen causing the disease rainbow trout fry syndrome (RTFS), which has important implications for aquaculture production and trade worldwide. RTFS can be treated by antibiotic administration, but with the increasing problem of antibiotic resistant bacteria......, the use of lytic bacteriophages is a promising alternative approach to disease control in aquaculture. Bacteriophage control of bacterial infections depends on efficient delivery of the phages to the infected organs, and in this study we therefore examined the occurrence and persistence of phages...

  14. Aeromonas australiensis sp. nov., isolated from irrigation water.

    Science.gov (United States)

    Aravena-Román, Max; Beaz-Hidalgo, Roxana; Inglis, Timothy J J; Riley, Thomas V; Martínez-Murcia, Antonio J; Chang, Barbara J; Figueras, Maria Jose

    2013-06-01

    A Gram-negative, facultatively anaerobic bacillus, designated strain 266(T), was isolated from an irrigation water system in the south-west of Western Australia. Analysis of the 16S rRNA gene sequence confirmed that strain 266(T) belonged to the genus Aeromonas, with the nearest species being Aeromonas fluvialis (99.6% similarity to the type strain, with 6 nucleotide differences) followed by Aeromonas veronii and Aeromonas allosaccharophila (both 99.5%). Analysis of gyrB and rpoD sequences suggested that strain 266(T) formed a phylogenetic line independent of other species in the genus. This was confirmed using the concatenated sequences of six housekeeping genes (gyrB, rpoD, recA, dnaJ, gyrA and dnaX) that also indicated that A. veronii and A. allosaccharophila were the nearest relatives. DNA-DNA reassociation experiments and phenotypic analysis further supported the conclusion that strain 266(T) represents a novel species, for which the name Aeromonas australiensis sp. nov. is proposed, with type strain 266(T) (=CECT 8023(T) =LMG 26707(T)). [corrected].

  15. Enhancement of protective immunity in European eel(Anguilla anguilla)against Aeromonas hydrophila and Aeromonas sobria by a recombinant Aeromonas outer membrane protein

    Institute of Scientific and Technical Information of China (English)

    Ruizhang Guan; Jing Xiong; Wenshu Huang; Songlin Guo

    2011-01-01

    To develop a vaccine,which can simultaneously prevent the diseases caused by various pathogenic bacteria in fish,we try to find a conserved outer membrane protein(OMP)antigen from different bacterial pathogens.In this study,an OMP fragment of 747 by(named as Omp-G),whichwas highly conserved in seven Aeromonas OMP sequences from the NCBI database,was amplified by PCR from one Aeromonas sobria strain(1110)and two Aeromonas hydrophila strains(1327 and B33)with the designed specific primers.The sequence was cloned into pGEX-2T(6 × His-tag)vector,expressed in Escherichia coli system,and then the recombinant protein(named as rOmp-G)was purified with nickel chelating affinity chromatography.The purified romp-G showed a good immunogenicity in rabbits and well-conserved characteristics in these three pathogens by enzyme-linked immunosorbed assay.Furthermore,the rOmp-G also showed good immunogenicity in eels(Anguilla anguilla)for eliciting significantly increased specific antibodies(P<0.01),and providing higher protection efficiencies(P<0.05)after the pathogens challenge.The values of the relative percent survival in eels were 70% and 50% for two A.hydrophila strain challenge,and 75% for A.sobria strain challenge.This is the first report of a potential vaccination in eels that simultaneously provide protectiveness against different Aeromonas pathogens with a conserved partial OMP.

  16. Reclassification of Aeromonas hydrophila subsp. dhakensis Huys et al. 2002 and Aeromonas aquariorum Martínez-Murcia et al. 2008 as Aeromonas dhakensis sp. nov. comb nov. and emendation of the species Aeromonas hydrophila.

    Science.gov (United States)

    Beaz-Hidalgo, Roxana; Martínez-Murcia, Antonio; Figueras, Maria José

    2013-05-01

    Previous studies indicate that Aeromonas aquariorum and Aeromonas hydrophila subsp. dhakensis are the same taxon and suggest that they should be synonymized. Using a polyphasic approach, the phenotypic and phylogenetic relationship of A. aquariorum with the 3 defined A. hydrophila subspecies (i.e. dhakensis, hydrophila, ranae) was investigated. Phylogenetic trees derived from the 16S rRNA, rpoD or gyrB genes and a multilocus phylogenetic analysis (with the concatenated sequences of gyrB, rpoD, recA, dnaJ and gyrA) confirmed that both A. aquariorum and A. hydrophila subsp. dhakensis are a unique taxon, different from the other A. hydrophila subspecies, corroborating the phenotypic and DNA-DNA hybridization (DDH) results. A formal synonymization of A. aquariorum and A. hydrophila subsp. dhakensis and a reclassification of both as Aeromonas dhakensis sp. nov. comb nov. is therefore proposed.

  17. Dispersal and survival of Flavobacterium psychrophilum phages in vivo in rainbow trout and in vitro under laboratory conditions: implications for their use in phage therapy.

    Science.gov (United States)

    Madsen, Lone; Bertelsen, Sif K; Dalsgaard, Inger; Middelboe, Mathias

    2013-08-01

    Attention has been drawn to phage therapy as an alternative approach for controlling pathogenic bacteria such as Flavobacterium psychrophilum in salmonid aquaculture, which can give rise to high mortalities, especially in rainbow trout fry. Recently, phages have been isolated with a broad host range and a strong lytic potential against pathogenic F. psychrophilum under experimental conditions. However, little is known about the fate of phages at environmental conditions. Here, we quantified the dispersal and fate of F. psychrophilum phages and hosts in rainbow trout fry after intraperitoneal injection. Both phages and bacteria were isolated from the fish organs for up to 10 days after injection, and coinjection with both bacteria and phages resulted in a longer persistence of the phage in the fish organs, than when the fish had been injected with the phages only. The occurrence of both phage and bacterium was most prevalent in the kidney and spleen, with only minor occurrence in the brain. The experiment showed that injected phages were rapidly spread in the internal organs of the fish, also in the absence of bacteria. Parallel examination of the regulation of bacteriophage infectivity in controlled laboratory experiments at various environmental conditions showed that pH had only minor effects on long-term (3 months) phage infectivity within a pH range of 4.5 to 7.5, whereas phage infectivity was immediately lost at pH 3. In the absence of host cells, phage infectivity decreased by a factor of 10,000 over 55 days in untreated pond water, while the sterilization and removal of particles caused a 100-fold increase in phage survival relative to the control. In addition, F. psychrophilum-specific phages maintained their infectivity for ∼2 months in glycerol at -80°C, whereas infectivity decreased by a factor 10 when kept in a buffer at 20°C. Only a very small degradation in infectivity was seen when bacteriophages were added and dried on fish feed pellets

  18. Susceptibility of Aeromonas Hydophila Isolates to Antimicrobial Drugs

    Directory of Open Access Journals (Sweden)

    Igor Stojanov

    2010-05-01

    Full Text Available Aeromonas hydrophila is a microorganism widely distributed in nature: in water, soil, food. It is also part of the normal bacterial flora of many animals. As an opportune microorganism it is a secondary biological agent that contributes to the occurrence of a fish disease and its deterioration. Frequently, its presence is an indication of bad zoohygiene and zootechnical conditions in fish ponds. Reduced quality and quantity of feed, mechanical injuries, parasitosis, seasonal oscillation in temperature present some of the factors that produce favorable conditions for bacterial proliferation of aeromonas in fish ponds, so clinical symptoms of the disease occur. Aeromonas is almost always present in clinical isolates and may be unjustly accused for bad health of fish. Antibiotic therapy is applied even when the clinical findings are clear, what certainly effects the susceptibility to chemotherapeutics. The subject of our work was bacteriological examination of the material obtained from the carps with the observed skin changes and the carps without these changes. Also, antimicrobial susceptibility of Aeromonas hydrophila was tested. The aim of this research was to determined the presence of Aeromonas hydrophilia in the carp ponds and to test antibiotic susceptibility. The material consisted of the samples from the fish ponds where the carps were with and without changed skin. The method the isolation of Aeromonas hydrophila was used. The diffusion disk technique was used for testing antibiotic susceptibility. The isolates were tested for their susceptibility to Florephenikol, Flumequine, Olaqindox and Oxitetracycline. The obtained results point that antimicrobial susceptibility was the same regardless of the origin of the samples, i.e. the resistance was the same for both groups of samples (the strains isolated from the fish with skin changes and the strains from fish without changes on skin. The strains were highly resistant: 35% were resistant to

  19. Bactérias do gênero Aeromonas em abatedouro de frangos Contamination by Aeromonas spp. in poultry slaughterhouse

    Directory of Open Access Journals (Sweden)

    F.N. Costa

    2002-10-01

    Full Text Available Analisaram-se 200 amostras de diferentes produtos e locais do fluxograma de abate de frangos com o objetivo de identificar os pontos de contaminação da carne de frango por Aeromonas. Das 25 amostras analisadas para cada um dos oito pontos estudados foram isoladas Aeromonas spp. em nove (36% amostras de penas, em 14 (56% de fezes, em 18 (72% de carcaças não evisceradas, evisceradas e resfriadas e em 20 (80% de água do pré-resfriamento. Não foram isoladas Aeromonas spp. da água de abastecimento da indústria e da água do tanque de escaldagem. Foram identificadas as espécies, Aeromonas hydrophila em 39 (15,2% amostras, A. sobria em 69 (26,9%, A. caviae em 87 (34%, A. veronii em 18 (7%, A. schubertii em três (1,2%, A. trota em duas (0,8% e A. jandaei em uma (0,4%. O resultado sugere que independente do controle higiênico-sanitário adotado na indústria, as carcaças de frangos podem se contaminar já a partir de sua obtenção, determinando o aparecimento de Aeromonas em carcaças resfriadas e prontas para a comercialização.Two hundred samples of poultry meat were analyzed in order to evaluate contamination by Aeromonas spp. in eight sites of a slaughterhouse, with 25 samples obtained in each site. Aeromonas spp. was found in nine (36.0% samples of feathers, 14 (56.0% samples of stools, 18 (72.0% carcasses after pre-evisceration, post-evisceration, and cooling, as well as in 20 (80.0% samples of chilling water. The microorganism was not found in samples from either the supplying water or the tank for scalding water. Aeromonahydrophila was identified in 39 (15.2% samples, whereas A. sobria, A. caviae, A. veronii, A. schubertii, A. trota, and A. jandaei were identified in, respectively, 69 (26.9%, 87 (34.0%, 18 (7.0%, three (1.2%, two (0.8%, and one (0.4% samples. In addition, bacteria dissemination may occur during slaughtering and regardless the hygienic-sanitary control followed by the industry, poultry carcasses may be contaminated

  20. Caracterização de Aeromonas spp isoladas de neonatos hospitalizados Characterization of Aeromonas spp isolates from newborns hospitalized

    OpenAIRE

    2008-01-01

    Aeromonas spp é reconhecida como patogênica para o homem após o consumo de água e alimentos contaminados. Na presente investigação, foram avaliadas 2.323 amostras de swabs retais de neonatos hospitalizados no Rio de Janeiro objetivando o isolamento de Aeromonas. As amostras foram coletadas e enviadas ao Laboratório de Referência Nacional de Cólera e outras enteroinfecções bacterianas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz. Os swabs foram submetidos ao enriquecimento em água peptonada ...

  1. Diarrea del viajero asociada a Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    M. Martín Delgado

    2001-06-01

    Full Text Available Aeromonas hydrophila es una bacteria que se encuentra frecuentemente en aguas dulces y salobres. Desde hace varios años se conoce que determinadas cepas de la especie pueden causar enfermedad en pescados y en anfibios, existiendo cierta controversia sobre su patogeneicidad en humanos. No obstante, puede dar lugar a infección en personas, que la adquieren bien a través de heridas abiertas o bien por ingestión de alimentos o agua contaminados. Sin embargo, en prácticamente la totalidad de las publicaciones se hace referencia a casos aislados más que a brotes producidos por esta bacteria. Generalmente la infección por A. hydrophila da lugar a gastroenteritis en personas sanas, pudiendo generar una septicemia en individuos inmunodeprimidos.En 1998 se produjo una alarma en el sector hotelero por un incremento considerable de los casos de gastroenteritis entre los turistas que acudían durante sus vacaciones a determinadas zonas costeras de la isla de Tenerife.Tras tener conocimiento de la situación, la Dirección General de Salud Pública inició una investigación epidemiológica con el objetivo de conocer la magnitud real del problema detectado e identificar los factores asociados a la misma, para poner en marcha las medidas correctoras y de control necesarias. El análisis inicial permitió determinar que se trataba de un proceso de gran magnitud en su extensión aunque de carácter leve, que afectaba únicamente a los turistas en una zona costera en concreto, compatible por lo tanto con la diarrea del viajero, planteándose un origen probablemente hídrico.

  2. Genome Sequence of Hypervirulent Aeromonas hydrophila Strain HZAUAH

    Science.gov (United States)

    Teng, Lin; Deng, Limei; Dong, Xingxing; Wei, Shun; Li, Jinquan

    2017-01-01

    ABSTRACT Aeromonas hydrophila, a zoonotic bacterium found in an expansive range of aquatic ecosystems, has been reported to cause severe diseases in fish, amphibians, reptiles, and mammals, including humans. Herein, we report the draft genome of the hypervirulent A. hydrophila strain HZAUAH isolated from a crucian in China. PMID:28302770

  3. Oral Challenge with Aeromonas in Protein-Malnourished Mice

    Science.gov (United States)

    1994-01-01

    precipitaion after boiling. SRBC. sheep diarrhoea (RITARD) model (25) have red blood cells (hmolysis): Yt. adrenal cell culture; CHO. Chinese hamster...did not seem to affect the susceptibility of mice to deficient substitute for colostrum was not available. Aeromonas spp. infection, but there may be

  4. Aeromonas hydrophila disturbs water and electrolyte transport in ...

    African Journals Online (AJOL)

    SERVER

    2008-02-19

    Feb 19, 2008 ... The sacs were exposed to bacteria suspension (108 cells/ ml) at 25°C for 2 h. Our results ... pathogenic, causing fish diseases. Several studies have shown that Aeromonas affects both fish and sea fruit. (Paniagua et al., 1990) ...

  5. Aeromonas spp. in het Nederlandse drinkwater; een orienterend onderzoek

    NARCIS (Netherlands)

    Versteegh JFM; During M; Havelaar AH; Koot W

    1986-01-01

    In dit rapport worden uitvoering en resultaten van een orienterend onderzoek naar het voorkomen van Aeromonas spp. in het Nederlandse drinkwater in 1985 besproken. Het bleek dat in 71% van de onderzochte monsters (rein water "af pompstation" en water uit het distributienet) in 100 ml gee

  6. SENSITIVITY OF DIFFERENT AEROMONAS SPECIES TO COPPER AND SILVER

    Science.gov (United States)

    Aeromonas bacteria are common flora in surface and ground waters and are considered to be human pathogens. They can also be found in municipally treated drinking water, likely as a component of biofilms, as found in distribution system pipes and point of use water filters. It ...

  7. Production and properties of lipase of Aeromonas sobria.

    Science.gov (United States)

    Takahashi, Eizo; Ito, Hidenobu; Kobayashi, Hidetomo; Yamanaka, Hiroyasu; Takeda, Yoshifumi; Balakrish Nair, Gopinath; Arimoto, Sakae; Negishi, Tomoe; Okamoto, Keinosuke

    2012-05-01

    Aeromonas have been isolated from a wide variety of aquatic environments. However the number of Aeromonas in sea water is extremely small compared to that in fresh water. In in vitro culture, Aeromonas can grow in mediums containing NaCl at a concentration of 3.0%, this concentration corresponding to that of sea water. It is unclear why the number of Aeromonas is low in sea water. Exoproteins of bacteria are thought to be important for bacterial growth and survival in the environment. Previously, the present authors have shown that mediums containing 3.0% NaCl suppress production of two proteases, serine protease and metalloprotease. In this experiment, other exoproteins whose production is influenced by the amount of NaCl in the medium were analyzed. A protein whose production is repressed in medium containing 3.0% NaCl was found and purified. Biological assay of the purified protein showed that it degrades tributyrin and hydrolyzes para-nitrophenyl-fatty acylesters. These results show that the protein is a lipase. Subsequently, the nucleotide sequence of the gene encoding the lipase was determined and the amount of mRNA of the lipase gene in the cells measured. It was found that transcription of the gene is not inhibited by NaCl in the medium. This result indicates that the lipase might be synthesized, but the folding process to become an active structure does not progress smoothly in a medium containing 3.0% NaCl.

  8. Expression profiling reveals Spot 42 small RNA as a key regulator in the central metabolism of Aliivibrio salmonicida

    Directory of Open Access Journals (Sweden)

    Hansen Geir Å

    2012-01-01

    Full Text Available Abstract Background Spot 42 was discovered in Escherichia coli nearly 40 years ago as an abundant, small and unstable RNA. Its biological role has remained obscure until recently, and is today implicated in having broader roles in the central and secondary metabolism. Spot 42 is encoded by the spf gene. The gene is ubiquitous in the Vibrionaceae family of gamma-proteobacteria. One member of this family, Aliivibrio salmonicida, causes cold-water vibriosis in farmed Atlantic salmon. Its genome encodes Spot 42 with 84% identity to E. coli Spot 42. Results We generated a A. salmonicida spf deletion mutant. We then used microarray and Northern blot analyses to monitor global effects on the transcriptome in order to provide insights into the biological roles of Spot 42 in this bacterium. In the presence of glucose, we found a surprisingly large number of ≥ 2X differentially expressed genes, and several major cellular processes were affected. A gene encoding a pirin-like protein showed an on/off expression pattern in the presence/absence of Spot 42, which suggests that Spot 42 plays a key regulatory role in the central metabolism by regulating the switch between fermentation and respiration. Interestingly, we discovered an sRNA named VSsrna24, which is encoded immediately downstream of spf. This new sRNA has an expression pattern opposite to that of Spot 42, and its expression is repressed by glucose. Conclusions We hypothesize that Spot 42 plays a key role in the central metabolism, in part by regulating the pyruvat dehydrogenase enzyme complex via pirin.

  9. Clinical implications of species identification in monomicrobial Aeromonas bacteremia.

    Directory of Open Access Journals (Sweden)

    Chi-Jung Wu

    Full Text Available Advances in Aeromonas taxonomy have led to the reclassification of aeromonads. Hereon, we aimed to re-evaluate the characteristics of Aeromonas bacteremia, including those of a novel species, Aeromonas dhakensis.A retrospective study of monomicrobial Aeromonas bacteremia at a medical center in southern Taiwan from 2004-2011 was conducted. Species identification was based on rpoB sequencing. Of bacteremia of 153 eligible patients, A. veronii (50 isolates, 32.7%, A. dhakensis (48, 31.4%, A. caviae (43, 28.1%, and A. hydrophila (10, 6.5% were the principal causative species. A. dhakensis and A. veronii bacteremia were mainly community-acquired and presented as primary bacteremia, spontaneous bacterial peritonitis, or skin and soft-tissue infection, whereas A. caviae was associated with hospital-onset bacteremia. The distribution of the AmpC β-lactamase and metallo-β-lactamase genes was species-specific: bla(AQU-1, bla(MOX, or bla(CepH was present in A. dhakensis, A. caviae, or A. hydrophila, respectively, and bla(CphA was present in A. veronii, A. dhakensis, and A. hydrophila. The cefotaxime resistance rates of the A. caviae, A. dhakensis, and A. hydrophila isolates were higher than that of A. veronii (39.5%%, 25.0%, and 30% vs. 2%, respectively. A. dhakensis bacteremia was linked to the highest 14-day sepsis-related mortality rate, followed by A. hydrophila, A. veronii, and A. caviae bacteremia (25.5%, 22.2%, 14.0%, and 4.7%, respectively; P = 0.048. Multivariate analysis revealed that A. dhakensis bacteremia, active malignancies, and a Pitt bacteremia score ≥ 4 was an independent mortality risk factor.Characteristics of Aeromonas bacteremia vary between species. A. dhakensis prevalence and its associated poor outcomes suggest it an important human pathogen.

  10. Hemolytic Activity and Siderophore Production in Different Aeromonas Species Isolated from Fish

    OpenAIRE

    Santos, Jesús A.; González, César J.; Otero, Andrés; García-López, María-Luisa

    1999-01-01

    The hemolytic activity and siderophore production of several strains of motile aeromonads were determined. The hemolytic activity of Aeromonas caviae and Aeromonas eucrenophila was enhanced after trypsinization of the samples. The enhancement of hemolysis was observed in strains that carried an aerolysin-like gene, detected by a PCR procedure. Siderophore production was demonstrated in all but one strain of Aeromonas jandaei. No apparent relationship was observed between the presence of plasm...

  11. Antibiotic resistance in Aeromonas upstream and downstream of a water resource recovery facility.

    Science.gov (United States)

    Cisar, Cindy R; Henderson, Samantha K; Askew, Maegan L; Risenhoover, Hollie G; McAndrews, Chrystle R; Kennedy, S Dawn; Paine, C Sue

    2014-09-01

    Aeromonas strains isolated from sediments upstream and downstream of a water resource recovery facility (WRRF) over a two-year time period were tested for susceptibility to 13 antibiotics. Incidence of resistance to antibiotics, antibiotic resistance phenotypes, and diversity (based on resistance phenotypes) were compared in the two populations. At the beginning of the study, the upstream and downstream Aeromonas populations were different for incidence of antibiotic resistance (p resistance phenotypes (p antibiotic resistance in Aeromonas in stream sediments fluctuates considerably over time and (2) suggest that WRRF effluent does not, when examined over the long- term, affect antibiotic resistance in Aeromonas in downstream sediment.

  12. Incidence of Aeromonas bacteremia in Southern Taiwan: vibrio and Salmonella bacteremia as comparators.

    Science.gov (United States)

    Wu, Chi-Jung; Chen, Po-Lin; Tang, Hung-Jen; Chen, Hung-Mo; Tseng, Fan-Chen; Shih, Hsin-I; Hung, Yuan-Pin; Chung, Chih-Huan; Ko, Wen-Chien

    2014-04-01

    The aim of the investigation was to describe the incidence of Aeromonas bacteremia in a city with a population of about 1.87 million inhabitants, located in southern Taiwan, between 2008 and 2010. Such data were compared with the incidences of Vibrio and Salmonella bacteremia in the same period and the incidence of Aeromonas bacteremia in other countries in the literature. The data revealed the average annual incidences of bacteremia due to Aeromonas, Vibrio, and Salmonella species were 76, 38, and 103 cases/million inhabitants, respectively. The incidence of Aeromonas bacteremia was higher than those in Western countries.

  13. Interaction of Aeromonas strains with lactic acid bacteria via Caco-2 cells.

    Science.gov (United States)

    Hatje, E; Neuman, C; Katouli, M

    2014-01-01

    The genus Aeromonas includes some species that have now been identified as human pathogens of significant medical importance. We investigated the ability of 13 selected Aeromonas strains belonging to nine species isolated from clinical cases (n = 5), environmental waters (n = 5), and fish (n = 3) to adhere to and translocate Caco-2 cells in the absence and presence of two lactic acid bacteria (LAB), i.e., Lactobacillus acidophilus and Bifidobacterium breve. Aeromonas isolates were also assessed for their cytotoxicity, the presence of virulence genes, and hemolysin production. Among the clinical isolates, one strain of Aeromonas veronii biovar veronii and two strains of Aeromonas hydrophila carried cytotoxin (act), heat-labile toxin (alt), hemolysin (hlyA), and aerolysin (aerA) genes, were cytotoxic to Vero cells, produced hemolysin, and showed higher adherence to Caco-2 cells. In contrast, this was seen in only one environmental strain, a strain of A. veronii biovar sobria. When Aeromonas strains were coinoculated with LAB onto Caco-2 cells, their level of adhesion was reduced. However, their rate of translocation in the presence of LAB increased and was significantly (P Aeromonas and LAB strains could have a detrimental effect on the Caco-2 cells, allowing the Aeromonas to translocate more readily, or the presence of the LAB stimulated the Aeromonas strains to produce more toxins and/or increase their translocation rate.

  14. Detection of Aeromonas hydrophila Using Fiber Optic Microchannel Sensor

    Directory of Open Access Journals (Sweden)

    Samla Gauri

    2017-01-01

    Full Text Available This research focuses on the detection of Aeromonas hydrophila using fiber optic microchannel biosensor. Microchannel was fabricated by photolithography method. The fiber optic was chosen as signal transmitting medium and light absorption characteristic of different microorganisms was investigated for possible detection. Experimental results showed that Aeromonas hydrophila can be detected at the region of UV-Vis spectra between 352 nm and 354 nm which was comparable to measurement provided by UV spectrophotometer and also theoretical calculation by Beer-Lambert Absorption Law. The entire detection can be done in less than 10 minutes using a total volume of 3 μL only. This result promises good potential of this fiber optic microchannel sensor as a reliable, portable, and disposable sensor.

  15. Evolutionary Roots and Diversification of the Genus Aeromonas.

    Science.gov (United States)

    Sanglas, Ariadna; Albarral, Vicenta; Farfán, Maribel; Lorén, J G; Fusté, M C

    2017-01-01

    Despite the importance of diversification rates in the study of prokaryote evolution, they have not been quantitatively assessed for the majority of microorganism taxa. The investigation of evolutionary patterns in prokaryotes constitutes a challenge due to a very scarce fossil record, limited morphological differentiation and frequently complex taxonomic relationships, which make even species recognition difficult. Although the speciation models and speciation rates in eukaryotes have traditionally been established by analyzing the fossil record data, this is frequently incomplete, and not always available. More recently, several methods based on molecular sequence data have been developed to estimate speciation and extinction rates from phylogenies reconstructed from contemporary taxa. In this work, we determined the divergence time and temporal diversification of the genus Aeromonas by applying these methods widely used with eukaryotic taxa. Our analysis involved 150 Aeromonas strains using the concatenated sequences of two housekeeping genes (approximately 2,000 bp). Dating and diversification model analyses were performed using two different approaches: obtaining the consensus sequence from the concatenated sequences corresponding to all the strains belonging to the same species, or generating the species tree from multiple alignments of each gene. We used BEAST to perform a Bayesian analysis to estimate both the phylogeny and the divergence times. A global molecular clock cannot be assumed for any gene. From the chronograms obtained, we carried out a diversification analysis using several approaches. The results suggest that the genus Aeromonas began to diverge approximately 250 millions of years (Ma) ago. All methods used to determine Aeromonas diversification gave similar results, suggesting that the speciation process in this bacterial genus followed a rate-constant (Yule) diversification model, although there is a small probability that a slight

  16. Aeromonas spp.: evaluation of genomic diversity and biofilm forming ability

    OpenAIRE

    Craveiro, Sara Sofia Pereira, 1986-

    2013-01-01

    Tese de mestrado. Biologia (Microbiologia Aplicada). Universidade de Lisboa, Faculdade de Ciências, 2013 Aeromonas spp. are ubiquitous bacteria widely distributed among aquatic environments. Their persistence in water distribution systems is related to their ability to form biofilms, even in the presence of residual chlorine. Once in distribution water systems, aeromonads can contaminate drinking water, food processing facilities and food products. Moreover, members of this genus are known...

  17. Clinical and biochemical significance of toxin production by Aeromonas hydrophila.

    Science.gov (United States)

    Kindschuh, M; Pickering, L K; Cleary, T G; Ruiz-Palacios, G

    1987-05-01

    Production of cytotoxin and enterotoxin by Aeromonas strains obtained from stools of 50 children in Mexico and Texas and from blood of 9 children with sepsis was determined. Results were correlated with clinical features of infected children as well as with biochemical traits of Aeromonas strains. Cytotoxin was produced by 40 of 42 Aeromonas strains (95%) isolated from stools of children with diarrhea, by all 8 isolates from stools of well children, and by all 9 isolates from children with sepsis. There was no difference in the quantities (amount of cytotoxin per milligram of protein required to kill 50% of the cells) of cytotoxin produced and in clinical manifestations among the groups. None of the isolates produced a toxin that could be neutralized by antiserum raised against Shiga toxin produced by Shigella dysenteriae 1 60R. Heat-labile-like enterotoxin (LT) was produced by 26 of 42 stool isolates (62%), while only 1 of the 42 isolates (2%) produced enterotoxinlike activity in suckling mice; 65% of the cytotoxin-producing strains also produced an LT-like material. All strains from blood produced LT-like material, and 2 of 6 (33%) produced activity in suckling mice. All strains produced hemolysin; 37 of 57 (65%) were Voges-Proskauer positive; 27 of 57 (47%) were lysine decarboxylase positive by API 20E strips, none were positive for lysine decarboxylose production by lysin-iron agar slants at 24 h, but 17 of 54 (31%) were positive at 48 h. There was no correlation between biochemical reactions and enterotoxin or cytotoxin production. There appears to be no correlation between toxin production by Aeromonas spp. and gastroenteritis.

  18. Evolutionary Roots and Diversification of the Genus Aeromonas

    Science.gov (United States)

    Sanglas, Ariadna; Albarral, Vicenta; Farfán, Maribel; Lorén, J. G.; Fusté, M. C.

    2017-01-01

    Despite the importance of diversification rates in the study of prokaryote evolution, they have not been quantitatively assessed for the majority of microorganism taxa. The investigation of evolutionary patterns in prokaryotes constitutes a challenge due to a very scarce fossil record, limited morphological differentiation and frequently complex taxonomic relationships, which make even species recognition difficult. Although the speciation models and speciation rates in eukaryotes have traditionally been established by analyzing the fossil record data, this is frequently incomplete, and not always available. More recently, several methods based on molecular sequence data have been developed to estimate speciation and extinction rates from phylogenies reconstructed from contemporary taxa. In this work, we determined the divergence time and temporal diversification of the genus Aeromonas by applying these methods widely used with eukaryotic taxa. Our analysis involved 150 Aeromonas strains using the concatenated sequences of two housekeeping genes (approximately 2,000 bp). Dating and diversification model analyses were performed using two different approaches: obtaining the consensus sequence from the concatenated sequences corresponding to all the strains belonging to the same species, or generating the species tree from multiple alignments of each gene. We used BEAST to perform a Bayesian analysis to estimate both the phylogeny and the divergence times. A global molecular clock cannot be assumed for any gene. From the chronograms obtained, we carried out a diversification analysis using several approaches. The results suggest that the genus Aeromonas began to diverge approximately 250 millions of years (Ma) ago. All methods used to determine Aeromonas diversification gave similar results, suggesting that the speciation process in this bacterial genus followed a rate-constant (Yule) diversification model, although there is a small probability that a slight

  19. Screening and Characterization of a Bioflocculant Produced by Aeromonas sp.

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To isolate the bioflocculant-producing bacteria from activated sludge and investigate the flocculating characteristics of the newly isolated bioflocculant. Methods Bacteria were screened from activated sludge samples to isolate bioflocculant-producing bacteria. Flocculating activity was used as a measure of the flocculating capability of the bioflocculant.Results A novel bioflocculant-producing bacterium was isolated, which was identified to belong to genus Aeromonas and named as Aeromonas sp. N11. Flocculating activity increased in the presence of K+, Na+, or Ca2+. The highest flocculating activities for kaolin suspension were obtained in acidic pH ranges, and optimum pHs for it were 3.0, 4.0, and 5.0 with 1 mmol/L K+, Ca+, and Na+ present, respectively. The highest flocculating activities for soil suspension were observed at pH 8.0. The bioflocculant had a good flocculating activity and could achieve a flocculating activity of 92.4% for kaolin suspension at a Conclusion The bioflocculant produced by Aeromonas sp. N11 has strong flocculating activity and high stability, which affords high possibility of its practical use.

  20. Flavobacterium psychrophilum y su patología en alevines de Onchorhynchus mykiss del centro piscícola El Ingenio, Huancayo

    Directory of Open Access Journals (Sweden)

    Jorge León

    2008-12-01

    Full Text Available En el presente trabajo se reporta la presencia de Flavobacterium psychrophilum, como agente causante de la patología “enfermedad bacteriana del agua fría” en alevines de Onchorhynchus mykiss “trucha arco iris” del Centro Piscícola El Ingenio, Junín (3250 m de altitud. La lesión macroscópica externa más frecuente fue la ulceración profunda de la región dorsal del pez acompañado de un ennegrecimiento localizado de la piel. Internamente se observó una marcada esplenomegalia, palidez del hígado, riñón y branquias, inflamación del intestino y acumulación de líquido ascítico en el peritoneo. No se detectó hemorragia interna. En Agar Cytophaga Modificado (ACM según Anaker & Ordal (1959 fueron aisladas inicialmente 29 Gram negativas, de las cuales según la caracterización fenotípica y pruebas bioquímicas 9 fueron consideradas como F. psychrophilum. Pruebas de susceptibilidad antibiótica mostraron alta sensibilidad de las cepas a Gentamicina, Ceftazidina, oxitetraciclina, Norfloxacina, furazolidona, Ciprofloxacina y Cefoxitina.

  1. Hemolytic activity in Flavobacterium psychrophilum is a contact-dependent, two-step mechanism and differently expressed in smooth and rough phenotypes.

    Science.gov (United States)

    Högfors-Rönnholm, Eva; Wiklund, Tom

    2010-12-01

    The hemolytic activity of cells of smooth and rough phenotypic variants of the Gram-negative fish pathogen Flavobacterium psychrophilum was investigated in two different assays, a microplate and an agarose hemolysis assay, using rainbow trout erythrocytes. The smooth cells showed a high and the rough cells a negligible, concentration dependent, hemolytic activity in the microplate assay. Both smooth and rough cells showed a rather weak hemolytic activity, with two distinct hemolytic patterns, in the agarose assay. The hemolytic activity of the cells was not regulated by iron availability and cell-free extracellular products did not show any hemolytic activity. The smooth cells, in contrast to the rough cells, showed a high ability to agglutinate erythrocytes and both hemagglutination and hemolytic activity was impaired by treatment of the cells with sialic acid. The hemolytic activity was furthermore reduced after proteolytic and heat treatment of the cells. The results from the present study suggest that the hemolytic activity in F. psychrophilum is highly expressed in the smooth phenotype, and that it is a contact-dependent and two-step mechanism that is initiated by the binding of the bacterial cells to the erythrocytes through sialic acid-binding lectins and then executed by thermolabile proteinaceous hemolysins.

  2. Diarrea del viajero asociada a Aeromonas hydrophila Traveller's diarrohea caused by Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    M. L. Pita Toledo

    2001-06-01

    Full Text Available Aeromonas hydrophila es una bacteria que se encuentra frecuentemente en aguas dulces y salobres. Desde hace varios años se conoce que determinadas cepas de la especie pueden causar enfermedad en pescados y en anfibios, existiendo cierta controversia sobre su patogeneicidad en humanos. No obstante, puede dar lugar a infección en personas, que la adquieren bien a través de heridas abiertas o bien por ingestión de alimentos o agua contaminados. Sin embargo, en prácticamente la totalidad de las publicaciones se hace referencia a casos aislados más que a brotes producidos por esta bacteria. Generalmente la infección por A. hydrophila da lugar a gastroenteritis en personas sanas, pudiendo generar una septicemia en individuos inmunodeprimidos.En 1998 se produjo una alarma en el sector hotelero por un incremento considerable de los casos de gastroenteritis entre los turistas que acudían durante sus vacaciones a determinadas zonas costeras de la isla de Tenerife.Tras tener conocimiento de la situación, la Dirección General de Salud Pública inició una investigación epidemiológica con el objetivo de conocer la magnitud real del problema detectado e identificar los factores asociados a la misma, para poner en marcha las medidas correctoras y de control necesarias. El análisis inicial permitió determinar que se trataba de un proceso de gran magnitud en su extensión aunque de carácter leve, que afectaba únicamente a los turistas en una zona costera en concreto, compatible por lo tanto con la diarrea del viajero, planteándose un origen probablemente hídrico.Aeromonas hydrophila is a bacteria frequently found in fresh water and saline water. Certain strains of the species have been known to cause disease in fish and amphibians for several years, although some controversy exists about its ability to cause illness in humans. Nevertheless, either through open wounds or contaminated food or water, it can give rise to infection. However, almost

  3. Aeromonas hydrophila urinary tract infection in pregnancy- Case report and literature review

    Directory of Open Access Journals (Sweden)

    Latha Ragunathan

    2012-03-01

    Full Text Available A case of a pregnant woman without previous or concomitant disease, who developed an Aeromonas hydrophila urinarytract infection (UTI at 12 weeks gestation, is reported. A brief review of the literature on the association and incidenceof Aeromonas spp in urinary infections and also in association with pregnancy is presented. J Microbiol Infect Dis 2012;2(1: 26-28

  4. Chitin degradation and utilization by virulent Aeromonas hydrophila strain ML10-51K

    Science.gov (United States)

    Virulent Aeromonas hydrophila (vAh) is one of the most important bacterial pathogens that causes persistent outbreaks of motile Aeromonas septicemia (MAS) in warm-water fishes. Among factors associated with MAS outbreaks, the survivability of this pathogen in aquatic environments is of great concern...

  5. Complete genome sequence of channel catfish epidemic isolate Aeromonas hydrophila ML09-119

    Science.gov (United States)

    Aeromonas hydrophila is a Gram-negative, rod-shaped, mesophilic bacteria that infects both aquatic poikilothermic animals and mammals, including humans. Here, we present the complete genome sequence of Aeromonas hydrophila ML-09-119, which represents a clonal group of A. hydrophila isolates causing ...

  6. Classification of a hypervirulent Aeromonas hydrophila pathotype responsible for epidemic outbreaks in warm-water fishes

    Science.gov (United States)

    Lineages of hypervirulent Aeromonas hydrophila (vAh) are the cause of persistent outbreaks of motile Aeromonas septicemia in warm-water fishes worldwide. Over the last decade, this virulent lineage of A. hydrophila has resulted in annual losses of millions of tons of farmed carp and catfish in the P...

  7. Aeromonas detection and characterization using genus-specific PCR and single-strand conformation polymorphism (SSCP).

    Science.gov (United States)

    Delamare, Ana Paula Longaray; Lucena, Roberto Francisco; Thomazi, Guilherme; Ferrarini, Shana; Zacaria, Jucimar; Echeverrigaray, Sergio

    2012-10-01

    Based on sequence alignment, oligonucleotide primers targeting the Aeromonas extracellular lipase gene were developed for PCR detection of member of the genus. A pair of primers designed for conserved regions of the gene amplified a 276 bp sequence in all Aeromonas species and tested strains, but did not have a positive result with other Gram-positive and Gram-negative bacteria, showing high specificity and sensitivity. Selective enrichment in alkaline peptone water, followed by centrifugation, and direct usage of cells suspension as template, detected initial populations of 10 c.f.u. ml⁻¹. Single-strand conformation polymorphism analysis of the PCR products allowed the characterization of Aeromonas strains with a high discriminatory power (Simpson's index = 0.988). The method presented here provides a useful tool for the rapid detection of Aeromonas and the characterization of Aeromonas isolates.

  8. Genome sequencing and annotation of Aeromonas sp. HZM

    Directory of Open Access Journals (Sweden)

    Patric Chua

    2015-09-01

    Full Text Available We report the draft genome sequence of Aeromonas sp. strain HZM, isolated from tropical peat swamp forest soil. The draft genome size is 4,451,364 bp with a G + C content of 61.7% and contains 10 rRNA sequences (eight copies of 5S rRNA genes, single copy of 16S and 23S rRNA each. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession no. JEMQ00000000.

  9. Effect of solar irradiation on extracellular enzymes of Aeromonas proteolytica

    Science.gov (United States)

    Foster, B. G.

    1973-01-01

    The bacterium Aeromonas proteolytica was selected for studying the effects of solar irradiation on extracellular enzymes because it produces an endopeptidase that is capable of degrading proteins and a hemolysin that is active in lysing human erythrocytes. Possible alterations in the rate of enzyme production in response to the test conditions are currently underway and are not available for this preliminary report. Completed viability studies are indicative that little difference exists among the survival curves derived for cells exposed to various components of ultraviolet irradiation in space.

  10. Multifocal Aeromonas Osteomyelitis in a Child with Leukemia

    Directory of Open Access Journals (Sweden)

    Dimitrios Doganis

    2016-01-01

    Full Text Available Aeromonas hydrophila is a Gram negative organism causing both intestinal and extraintestinal disease. The case of a 14-year-old girl with underlying immunodeficiency and leukemia who developed systemic A. hydrophila infection is described in this report. While in deep bone marrow aplasia she developed fever, severe pain in the lower extremities, and swelling of the left femur. Blood culture showed Escherichia coli and A. hydrophila whereas pus culture from the soft tissue swelling showed the presence of A. hydrophila. Imaging studies showed diffuse osteolytic lesions. Patient received 5 months of intravenous and oral antibiotics and she improved clinically whereas the radiology findings persisted.

  11. Use of Aeromonas as a process indicator during swine carcass dressing and cutting

    Science.gov (United States)

    Palumbo, Samuel A.; Yu, Linda S. L.

    1999-01-01

    Using starch ampicillin agar, qualitative and quantitative determinations of Aeromonas spp. were made at several sites during swine carcass dressing and cutting. Aeromonas spp. were observed at all sites surveyed. Levels increased during shackling and passage through the first and middle polisher/washers, and significantly decreased during the singeing steps. Passage through the final polisher/washer caused a small increase in levels in Aeromonas spp. and these levels then remained constant during the rest of the carcass dressing operation. Aeromonas spp. were also isolated from the room where the carcasses were cut into wholesale cuts and cuts for further processing. Presumptive Aeromonas spp. cultures isolated from the different sites were confirmed as belonging to the genus Aeromonas and then speciated using the biochemical scheme of Joseph and Carnahan; 81% of the cultures were identified at A. hydrophila. Since most isolates were A. hydrophila, determination of the origin of isolates from different sites in the processing plant must await utilizing molecular biotyping techniques on the cultures. These results indicate the Aeromonas spp. occurs extensively in the swine dressing environment and thus represents a possible public health hazard and potential spoilage concern. Changes in cleaning and sanitizing of equipment may be necessary during swine carcass dressing and cutting to guard against this pathogen.

  12. Detection of antibiotic resistance, virulence gene determinants and biofilm formation in Aeromonas species isolated from cattle.

    Science.gov (United States)

    Igbinosa, Isoken H; Igbinosa, Etinosa O; Okoh, Anthony I

    2015-11-01

    This study aimed to assess the antibiogram of Aeromonas strains recovered from cattle faeces and the potential pathogenic status of the isolates. The antibiogram of the Aeromonas isolates demonstrated total resistance to clindamycin oxacillin, trimethoprim, novobiocin and ticarcillin. However, Aeromonas strains were sensitive to cefotaxime, oxytetracycline and tobramycin. The Aeromonas strains from Lovedale and Fort Cox farms were found to possess some virulence genes. The percentage distribution was aer 71.4%, ast 35.7%, fla 60.7%, lip 35.7% and hlyA 25% for Lovedale farm and aer 63.1%, alt 10.5%, ast 55.2%, fla 78.9%, lip 21% and hlyA 35.9% for Fort Cox farm. Class 1 integron was present in 27% of Aeromonas isolates; the bla TEM gene was present in 34.8%, while the blaP1 class A β-lactamase gene was detected in 12.1% of the isolates. Approximately 86% of the isolates formed a biofilm on microtitre plates. The presence of multiple antibiotic resistance and virulence genes in Aeromonas isolates from cattle faeces reveals the pathogenic and infectious importance of these isolates and is of great significance to public health. The possession of a biofilm-forming capability by such isolates may lead to difficulty during the management of infection related to Aeromonas species.

  13. Simultaneous demonstration of infectious pancreatic necrosis virus (IPNV) and Flavobacterium psychrophilum in paraffin-embedded specimens of rainbow trout Oncorhynchus mykiss fry by use of paired immunohistochemistry

    DEFF Research Database (Denmark)

    Evensen, Ø.; Lorenzen, Ellen

    1997-01-01

    be considered the primary cause of the mortality observed. Further, it may be difficult to cultivate the bacterium in later stages of the disease or from dead fish that have been transported without cooling. In the case of (suspected) double infections it is therefore suggested that immunohistochemistry......The Gram-negative bacterium Flavobacterium psychrophilum, which is the causative agent of rainbow trout fry syndrome (RTFS), and infectious pancreatic necrosis virus (IPNV), the causative agent of infectious pancreatic necrosis (IPN), are both highly pathogenic for rainbow trout fry. Several...... 'persistent' cases of RTFS have been observed concomitant with IPNV. Cultivation alone might not be sufficient for evaluation of the disease situation as both pathogens can be cultivated from fish that do not show any clinical signs of disease. In such cases it may be difficult to decide which pathogen should...

  14. [AEROMONAS BACTERIA ISOLATED FROM BITHYNIIDAE MOLLUSKS AND THEIR HABITATS: SPECIES COMPOSITION AND BIOLOGICAL PROPERTIES. COMMUNICATION 1].

    Science.gov (United States)

    Stepanova, T F; Bukharin, O V; Kataeva, L V; Perunova, N B; Karpukhina, N F

    2015-01-01

    The purpose of this investigation was to study the species composition and biological properties of Aeromonas bacteria isolated from Bithyniidae mollusks and their habitat (a water reservoir). The Bithyniidae mollusks and water from their habitat were the material to be studied. A total of 176 Aeromonas strains were isolated from the mollusks and water. A. veronii, A. hydrophila, and A. ichthiosmia were most common in the mollusks and A. veronii and A. ichthiosmia were in the water. All the strains isolated had hemolytic activity and no lysozyme or plasma coagulase activity. The magnitude of lecithinase and antilysozymic activities and biofilm formation of the Aeromonas bacteria varied with the isolation source of their strains.

  15. Lippia alba essential oil promotes survival of silver catfish (Rhamdia quelen) infected with Aeromonas sp.

    OpenAIRE

    FERNANDO J. SUTILI; Cunha,Mauro A.; Rosangela E. Ziech; Krewer,Carina C.; CARLA C. ZEPPENFELD; Heldwein, Clarissa G.; Gressler, Leticia T.; Berta M. Heinzmann; Agueda C. de Vargas; BERNARDO BALDISSEROTTO

    2015-01-01

    In vitro and in vivo activity of the Lippia alba essential oil (EO) against Aeromonas sp. was evaluated. In the in vitro assay the minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of EO for Aeromonas cells were determined using the microdilution method. Twenty five strains of Aeromonas sp. isolated from infected fish obtained from local fish farms were used. MIC and MBC values were 2862 and 5998 µg mL-1 for L. alba EO and 0.5 and 1.2 µg mL-1 for ...

  16. Necrotizing Fasciitis Secondary to Aeromonas Infection Presenting with Septic Shock

    Directory of Open Access Journals (Sweden)

    Nikhil Bhatia

    2017-01-01

    Full Text Available This report describes a case of necrotizing fasciitis presenting with septic shock due to an Aeromonas infection. The patient cut his foot while mowing the lawn and then spent time in a pool with black mold. He began feeling ill and developed swelling and a quarter-sized black area on his right lower extremity. Despite being hemodynamically unstable with systolic blood pressure in the low 70s, the patient was transferred to our facility from outside hospital 100 miles away. Upon arriving to facility, the patient appeared to be septic and the infected area of skin had grown. Irrigation and debridement were performed and appropriate antibiotic therapy was given; however, the patient subsequently died on hospital day 8. On review of the literature, cases of necrotizing fasciitis due to Aeromonas infection have been treated successfully with the aforementioned therapy; however, there is high mortality associated with these infections, many times related to a delayed diagnosis. Our patient also had multiple poor prognostic factors including hepatic dysfunction and immunosuppression.

  17. Incidence and toxigenicity of Aeromonas hydrophila in seafood.

    Science.gov (United States)

    Tsai, G J; Chen, T H

    1996-08-01

    Three selective media, Oxoid Aeromonas agar (OA), blood ampicillin agar (BA) and starch ampicillin agar (SA) were used to evaluate the presence of Aeromonas hydrophila in 66 samples of oyster, shrimp, fish and surimi products. Oyster had the highest incidence, with 50% positive, whilst no A. hydrophila was found in the surimi. Of the three selective media, BA displayed the highest recovery rate of A. hydrophila from seafood. Forty-eight isolates from this survey were tested for their capability to produce hemolysin and cytotoxin. Hemolysin was produced by 79.2% of the isolates and cytotoxin was produced by 91.7% of the isolates in brain heart infusion broth. One of the toxin-producing isolates from oyster, strain 8-169, was further tested for growth and toxin production in oyster, shrimp and fish at various temperatures. This particular isolate grew best and had highest toxin production in oyster. Hemolysin and cytotoxin were produced earlier at 28 degrees C than at 37 degrees C, and titers of hemolysin were also higher at 28 degrees C. At 5 degrees C, it was able to grow and produce hemolysin in oyster.

  18. Colonization of streptomycin-treated mice by Aeromonas species.

    Science.gov (United States)

    Sanderson, K; Ghazali, F M; Kirov, S M

    1996-03-01

    Streptomycin-treated adult mice were investigated as a possible model for studying the enteropathogenicity of Aeromonas species. C57BL mice pre-treated with streptomycin (5.0 g/L drinking water, 48 hours) received a single intragastric dose (10(10) bacteria /10.5 mL) of one of six well-characterized, toxin-producing, human diarrhoeal isolates of A. veronii biovar sobria (n = 3) or A. hydrophila (n = 3). Their faeces were examined for Aeromonas for 10 days post-challenge. All strains colonized the antibiotic-treated mice. Colonization did not occur in mice which did not receive streptomycin. Strains of A. hydrophila were recovered in greater numbers than strains of A. veronii biovar sobria, and colonized ( > or = 10(3) cfu/g of faeces) a greater proportion of mice at day 10. Strains of the latter species, however, were more adherent in cell line assays used as models of intestinal adhesion. A. hydrophila strains localized in the large intestine and appeared not to be cell associated. This study, therefore, points to species-related differences in intestinal colonization mechanisms. The streptomycin-treated adult mouse model may prove useful for further investigation of some of these mechanisms. Diarrhoeal symptoms were, however, not produced in this model.

  19. Genotypic and phenotypic identification of Aeromonas species and CphA-mediated carbapenem resistance in Queensland, Australia.

    Science.gov (United States)

    Sinclair, Holly A; Heney, Claire; Sidjabat, Hanna E; George, Narelle M; Bergh, Haakon; Anuj, Snehal N; Nimmo, Graeme R; Paterson, David L

    2016-05-01

    Infection caused by Aeromonas spp. ranges from superficial wound infection to life-threatening septicemia. Carbapenem resistance due to metallo-beta-lactamase, CphA encoded by the cphA gene, is a significant problem. This study defines Aeromonas spp. causing clinical disease in Queensland, Australia. Phenotypic tests for carbapenemase detection were assessed. One hundred Aeromonas isolates from blood (22), wound (46), sterile sites (11), stool (18), eye (2), and sputum (1) were characterized by rpoB and gyrB sequencing. Meropenem susceptibility by VITEK2, disk diffusion, and E-test MIC were determined. Carbapenemase production was assessed by Carba NP test and cphA by PCR. Gene sequencing identified isolates as Aeromonas dhakensis (39), Aeromonas veronii (21), Aeromonas hydrophila (20), Aeromonas caviae (14), Aeromonas jandaei (4), Aeromonas bestiarum (1), and Aeromonas sanarellii (1). Disk diffusion and E-test failed to detect resistance in isolates with presence of cphA. Carba NP was performed with 97.4% sensitivity and 95.7% specificity. Carbapenem resistance gene cphA was detected in A. veronii (21; 100%), A. hydrophila (18; 90%), A. dhakensis (34; 87.2%), A. jandaei (3; 75%), and A. bestiarum (1; 100%) but not A. caviae. We found that A. dhakensis was the predominant species, a previously unrecognized pathogen in this region.

  20. A comparative study of clinical Aeromonas dhakensis and Aeromonas hydrophila isolates in southern Taiwan: A. dhakensis is more predominant and virulent.

    Science.gov (United States)

    Chen, P-L; Wu, C-J; Chen, C-S; Tsai, P-J; Tang, H-J; Ko, W-C

    2014-07-01

    Aeromonas dhakensis, often phenotypically identified as Aeromonas hydrophila, is an important human pathogen. The present study aimed to compare the clinical and biological features of A. dhakensis and A. hydrophila isolates from human wounds. A total of 80 Aeromonas wound isolates collected between January 2004 and April 2011 were analysed. The species was identified by the DNA sequence matching of rpoD and gyrB (or rpoB if necessary). Most of the Aeromonas isolates were identified as A. dhakensis (37, 46.3%), and 13 (16.3%) as A. hydrophila. Both species alone can cause severe skin and soft-tissue infections. More A. dhakensis isolates were found in wounds exposed to environmental water (32.4% vs 0%, p 0.042). More biofilm formation was noted among A. dhakensis isolates (mean optical density at 570 nm, 1.23 ± 0.09 vs 0.78 ± 0.21, p 0.03). The MICs of ceftriaxone, imipenem and gentamicin for A. dhakensis isolates were higher (p Aeromonas wound isolates, and more virulent than A. hydrophila.

  1. Aeromonas hydrophila meningitis and fulminant sepsis in preterm newborn: A case report and review of literature

    Directory of Open Access Journals (Sweden)

    A Kali

    2016-01-01

    Full Text Available Neonatal meningitis is a lethal infection occurring in the 1st month of life. The risk of developing permanent neurological sequels is high among the neonates who survive. Bacterial pathogens are commonly associated with this condition. Aeromonas is a Gram-negative bacteria of aquatic habitat. Although isolation of Aeromonas species from neonates with blood stream infection is infrequently reported, neonatal meningitis caused by Aeromonas is exceedingly rare. We present a case of fulminant sepsis and meningitis caused by Aeromonas hydrophila in a preterm newborn male. The bacteria was isolated in culture from blood and cerebrospinal fluid. In spite of targeted antibiotics and supportive therapy, the baby failed to respond and died on the 12th day of life.

  2. Draft genome sequences of three Aeromonas hybrophila isolates from catfish and tilapia

    Science.gov (United States)

    Aeromonas hydrophila is a Gram-negative bacteria that is particularly adapted to freshwater environments and can cause severe infections in fish and humans. Here we report the draft genomes of three A. hydrophila catfish and tilapia isolates....

  3. HOST GENE CELL RESEARCH FOR DETERMINING VIRULENCE OF AEROMONAS SPP. COLLECTED FROM ENVIRONMENTAL SAMPLES

    Science.gov (United States)

    The United States Environmental Protection Agency (USEPA) is interested in assessing health risks associated with emerging or potential waterborne pathogens. To this end, the Agency has established a Candidate Contaminant List (CCL) that includes Aeromonas hydrophila an...

  4. IDENTIFICATION AND CHARACTERIZATION OF AEROMONAS ISOLATES FROM DRINKING WATER DISTRIBUTION SYSTEMS

    Science.gov (United States)

    Members of the bacterial genus Aeromonas are commonly isolated from both fresh and salt waters worldwide and some are believed to cause infections in humans, including gastroenteritis and wound infections. Currently, aeromonads are on the United States Environmental Protection A...

  5. Anti-biogram and resistogram profiling of Aeromonas species isolated from Malaysian aquatic sources

    OpenAIRE

    Olumide Adedokun Odeyemi; Asmat Ahmad

    2013-01-01

    Objective: To investigate antibiotics and heavy metals resistance profile of Aeromonas species isolated from Kuala Gula and Kuala Sepetang, Perak. Methods: Isolated Aeromonas species were subjected to 12 antibiotics: penicillin G 10 units, tetracycline 30 µg, novobiocin 5 µg, nitrofurantoin 100 µg, ampicillin 10 µg, chloramphenicol 10 µg, fluconazole 25 µg, gentamicin 10 µg, streptomycin 10 µg and 25 µg, kanamycin 30 µg, and vancomycin 30 µg and 5 heavy metals: MnSO4.H2O, Cr(NO...

  6. Correlation of the Suicide Phenomenon in Aeromonas Species with Virulence and Enteropathogenicity

    OpenAIRE

    1989-01-01

    Certain strains of mesophilic aeromonads (Aeromonas hydrophila, A. sorbria, and A. caviae), when grown in broth containing 0.5% glucose, undergo growth inhibition concomitant with acetate accumulation. Because these strains are nonviable after 24 h, this phenomenon is termed suicide. We investigated suicidal strains of Aeromonas species as a means of understanding animal virulence and enteropathogenicity. To assess virulence, batches of five white mice were inoculated intraperitoneally with 1...

  7. Isolation and Seroprevalence of Aeromonas spp. Among Common Food Animals Slaughtered in Nagpur, Central India.

    Science.gov (United States)

    Gowda, Tanuja K G M; Reddy, Vishwanatha R A P; Devleesschauwer, Brecht; Zade, Nandkishor N; Chaudhari, Sandeep P; Khan, Waqar A; Shinde, Shilpa V; Patil, Archana R

    2015-07-01

    Aeromonads are ubiquitous foodborne pathogens with a global distribution. Animal-origin foods and contaminated animals are the main sources of Aeromonas infection to humans. So far little is known about the occurrence of Aeromonas spp. in food-producing animals in India. The present study was conducted to determine the prevalence and seroprevalence of Aeromonas species from 50 each of meat, blood, and sera samples collected from cattle, buffaloes, goats, and pigs slaughtered in and around Nagpur, Central India. Alkaline peptone water and ampicillin dextrin agar were used to isolate Aeromonas spp. An indirect enzyme-linked immunosorbent assay (ELISA) was standardized by use of whole-cell antigen (WC) and outer membrane protein (OMP) of Aeromonas hydrophila (MTCC 646). Aeromonads were isolated from 44 (22%) of the meat samples, and 1 (0.5%) from the blood samples. Seroprevalence by indirect ELISA-based WC antigen was estimated as 68% in cattle, 44% in buffaloes, 60% in goats, and 30% in pigs. OMP-based ELISA yielded a seroprevalence of 56%, 48%, 52%, and 22% in cattle, buffaloes, goats, and pigs, respectively. The results revealed that OMP-based ELISA and WC-based ELISA were in agreement with one another. Isolation along with high seropositivity demonstrates the presence of foodborne Aeromonas spp. in the Nagpur city of Central India.

  8. High frequency of coinfecting enteropathogens in Aeromonas-associated diarrhea of hospitalized Peruvian infants.

    Science.gov (United States)

    Pazzaglia, G; Sack, R B; Salazar, E; Yi, A; Chea, E; Leon-Barua, R; Guerrero, C E; Palomino, J

    1991-06-01

    Rectal swabs from 391 infants less than 18 months of age who were hospitalized with acute diarrhea and from 138 similarly aged healthy infants were examined for the etiologic agents of diarrhea. Aeromonas spp. were recovered from 205 of 391 (52.4%) diarrheic patients, whereas they were recovered from 12 of 138 (8.7%) controls (P less than 10(-11). Among the 205 Aeromonas-positive diarrheic patients, 118 (57.6%) were found to be coinfected with other common enteropathogens. Of the 164 Aeromonas-positive initial diarrheic specimens, 82 (50.0%) had one or more other enteropathogens present; 30 patients were coinfected with rotavirus, 20 with enterotoxigenic Escherichia coli, 16 with Campylobacter spp., 14 with Shigella spp., 13 with enteropathogenic E. coli, 4 with Vibrio spp., 1 with Salmonella spp., and 1 with Plesiomonas spp. of Aeromonas strains from cases compared with that from controls supports an etiologic role for this organism. However, frequent concomitant infections with other well-recognized enteropathogens and a lack of disease correlation with common Aeromonas phenotypes suggest that only a subset of Aeromonas strains may be diarrhea causing and that such strains may be common to several of the existing species.

  9. Aeromonas hydrophila Septicemia in Acute Hand Injury: A Case Report

    Directory of Open Access Journals (Sweden)

    Chin-Chiang Yang

    2004-07-01

    Full Text Available Aeromonas hydrophila is an uncommon and frequently overlooked cause of skin and soft-tissue infection. Rapid onset of cellulitis and bullae formation in the setting of soft-tissue trauma in connection with exposure to fresh water should alert the clinician to the possibility of infection by this organism. We report a case of severe necrotizing fasciitis due to A. hydrophila infection involving the hand and arm, complicated by septicemia within 30 hours of injury. In addition to appropriate antibiotic therapy and general supportive care, treatment involves early surgical exploration for compartment decompression and aggressive debridement of all necrotic tissue followed by skin grafting for delayed wound closure. There was good functional outcome after more than 1 year of follow-up. Early awareness of A. hydrophila infection, as well as of infection by Vibrio, is necessary in preventing crippling deformities of the hand in post-traumatic wound infection with a history of exposure to fresh water.

  10. Isolation of Aeromonas hydrophila from the American alligator, Alligator mississippiensis

    Energy Technology Data Exchange (ETDEWEB)

    Gorden, R.W. (Univ. of Southern Colorado, Pueblo); Hazen, T.C.; Esch, G.W.; Fliermans, C.B.

    1979-04-01

    Aeromonas hydrophila was isolated from the internal organs of nine adult alligators, Alligator mississippiensis, which died without apparent cause, suggesting the bacterium may have been a factor. One hundred and twenty-three alligators ranging in age from six months to over 10 years were captured from five locations in the southeastern United States and sampled for A. hydrophila. The bacterium was isolated from the oral cavity of 85% of the animals, on the external jaw area from over 50% and from 70% of the internal tissue samples. A. hydrophila is ubiquitous with alligators in their natural habitats, but apparently does not cause clinical disease. However, stress factors such as trapping, handling, and warm water tempertures may be conducive to the rapid proliferation of the bacteria, thereby facilitating disease.

  11. Mortality of therapeutic fish Garra rufa caused by Aeromonas sobria

    Institute of Scientific and Technical Information of China (English)

    Juraj Majtn; Jaroslaverny; Alena Ofkan; Peter Tak; Milan Koznek

    2012-01-01

    Objective:To investigate a case of mass mortality of Garra rufa (G. rufa) from a fish hatchery farm in Slovakia. Methods: Causative bacterial agent was swabbing out of affected fish skin area and subsequently identified using commercial test system. Antibiotic susceptibility was determined by the disk diffusion method. Results: Infected G. rufa was characterized by abnormal swimming behaviour, bleeding of skin lesions and local haemorrhages. Despite of using recommended aquatic antibiotic treatment no improvement was achieved and Aeromonas sobria (A. sobria) was identified as a causative agent of fish mortality. Due to massive fish mortality, antibiotic susceptibility of pure isolated culture of A. sobria was evaluated employing eight antibiotics against human infections. A. sobria was resistant only against one antibiotic, namely ampicilin. Conclusions: These results indicate that A. sobria can act as a primary pathogen of G. rufa and may be a potential risk factor for immunodeficient or immunoincompetent patients during the ichthyotherapy.

  12. 气单胞菌和嗜水气单胞菌双重PCR检测方法的建立%Development of a duplex PCR for detection of Aeromonas spp.and Aeromonas hydrophila

    Institute of Scientific and Technical Information of China (English)

    潘晓艺; 沈锦玉; 郝贵杰; 姚嘉贇; 徐洋; 尹文林; 孙逢明; 吴颖蕾

    2011-01-01

    Aeromonas is one of the major pathogens which frequently cause the bacterial diseases in freshwater fish terrapin and crustaceans. Aeromonas hydrophila caused economic losses widely. In order to detect Aeromonas spp. And Aeromonas hydrophila, two pairs of specific primers were designed according to the glycerophospholipid-cholesterol acyltransferase (GCAT) gene of Aeromonas spp. And the 16S rRNA gene of Aeromonas hydrophila. So a duplex PCR assay was developed to amplify the 16S rRNA gene and the GCAT gene. The reaction conditions of the duplex PCR were optimized and PCR products were sequenced. Meanwhile, the specificity of duplex PCR was studied. Five Aeromonas hydrophila strains,seven Aeromonas strains and the other five strains of non Aeromonas were tested by duplex PCR. The results showed that the GCAT gene and the 16S rRNA gene could be amplified from Aeromonas hydrophila strains,but only the GCAT gene from the other Aeromonas species and neither from the other five strains. It could be concluded that the duplex PCR was specific and could be used in quick diagnose Aeromonas hydrophila and Aeromonas spp.%针对GenBank中登录的气单胞菌属(Aeromonas)的毒力基因甘油磷脂胆固醇酰基转移酶基因(GCA T)和嗜水气单胞菌(Aeromonash ydrophila)的16S rRNA基因的保守区设计2对特异性引物.通过进行双重PCR反应体系优化,PCR产物的测序鉴定和特异性试验,建立了一种能同时检测气单胞菌(Aeromonas spp.)和嗜水气单胞菌的双重PCR检测方法.用此方法对5株嗜水气单胞菌、7株其他不同种的气单胞菌和5株非气单胞菌属菌株进行双重PCR检测.结果显示,气单胞菌和嗜水气单胞菌在GCAT基因的扩增区都能得到有效扩增,其中嗜水气单胞菌能同时在16S rRNA基因扩增区得到有效扩增,而非气单胞菌属的菌株,在此两扩增区都为阴性,表明此检测方法可靠且可行.

  13. Detection and Quantification of Flavobacterium psychrophilum-Specific Bacteriophages In Vivo in Rainbow Trout upon Oral Administration: Implications for Disease Control in Aquaculture

    Science.gov (United States)

    Christiansen, Rói Hammershaimb; Dalsgaard, Inger; Middelboe, Mathias; Lauritsen, Anne H.

    2014-01-01

    The use of bacteriophages in the treatment and prevention of infections by the fish pathogen Flavobacterium psychrophilum has attracted increased attention in recent years. It has been shown recently that phage delivery via the parenteral route resulted in immediate distribution of phages to the circulatory system and the different organs. However, little is known about phage dispersal and survival in vivo in rainbow trout after delivery via the oral route. Here we examined the dispersal and survival of F. psychrophilum phage FpV-9 in vivo in juvenile rainbow trout after administration by three different methods—bath, oral intubation into the stomach, and phage-coated feed—with special emphasis on the oral route of delivery. Phages could be detected in all the organs investigated (intestine, spleen, brain, and kidney) 0.5 h postadministration, reaching concentrations as high as ∼105 PFU mg intestine−1 and ∼103 PFU mg spleen−1 within the first 24 h following the bath and ∼107 PFU mg intestine−1 and ∼104 PFU mg spleen−1 within the first 24 h following oral intubation. The phages were most persistent in the organs for the first 24 h and then decreased exponentially; no phages were detected after 83 h in the organs investigated. Phage administration via feed resulted in the detection of phages in the intestine, spleen, and kidney 1 h after feeding. Average concentrations of ∼104 PFU mg intestine−1 and ∼101 PFU mg spleen−1 were found throughout the experimental period (200 h) following continuous delivery of phages with feed. These experiments clearly demonstrate the ability of the phages to survive passage through the fish stomach and to penetrate the intestinal barrier and enter the circulatory system after oral delivery, although the quantity of phages found in the spleen was 100- to 1,000-fold lower than that in the intestine. It was also shown that phages could tolerate long periods of desiccation on the feed pellets, with 60% survival

  14. Detection and quantification of Flavobacterium psychrophilum-specific bacteriophages in vivo in rainbow trout upon oral administration: implications for disease control in aquaculture.

    Science.gov (United States)

    Christiansen, Rói Hammershaimb; Dalsgaard, Inger; Middelboe, Mathias; Lauritsen, Anne H; Madsen, Lone

    2014-12-01

    The use of bacteriophages in the treatment and prevention of infections by the fish pathogen Flavobacterium psychrophilum has attracted increased attention in recent years. It has been shown recently that phage delivery via the parenteral route resulted in immediate distribution of phages to the circulatory system and the different organs. However, little is known about phage dispersal and survival in vivo in rainbow trout after delivery via the oral route. Here we examined the dispersal and survival of F. psychrophilum phage FpV-9 in vivo in juvenile rainbow trout after administration by three different methods-bath, oral intubation into the stomach, and phage-coated feed-with special emphasis on the oral route of delivery. Phages could be detected in all the organs investigated (intestine, spleen, brain, and kidney) 0.5 h postadministration, reaching concentrations as high as ∼10(5) PFU mg intestine(-1) and ∼10(3) PFU mg spleen(-1) within the first 24 h following the bath and ∼10(7) PFU mg intestine(-1) and ∼10(4) PFU mg spleen(-1) within the first 24 h following oral intubation. The phages were most persistent in the organs for the first 24 h and then decreased exponentially; no phages were detected after 83 h in the organs investigated. Phage administration via feed resulted in the detection of phages in the intestine, spleen, and kidney 1 h after feeding. Average concentrations of ∼10(4) PFU mg intestine(-1) and ∼10(1) PFU mg spleen(-1) were found throughout the experimental period (200 h) following continuous delivery of phages with feed. These experiments clearly demonstrate the ability of the phages to survive passage through the fish stomach and to penetrate the intestinal barrier and enter the circulatory system after oral delivery, although the quantity of phages found in the spleen was 100- to 1,000-fold lower than that in the intestine. It was also shown that phages could tolerate long periods of desiccation on the feed pellets, with 60

  15. Antimicrobial Susceptibility of Flavobacterium psychrophilum from Chilean Salmon Farms and their Epidemiological Cut-off Values using Agar Dilution and Disk Diffusion Methods

    Directory of Open Access Journals (Sweden)

    Claudio D Miranda

    2016-11-01

    Full Text Available Flavobacterium psychrophilum is the most important bacterial pathogen for freshwater farmed salmonids in Chile. The aims of this study were to determine the susceptibility to antimicrobials used in fish farming of Chilean isolates and to calculate their epidemiological cut-off (COWT values. A number of 125 Chilean isolates of F. psychrophilum were isolated from reared salmonids presenting clinical symptoms indicative of flavobacteriosis and their identities were confirmed by 16S rRNA polymerase chain reaction. Susceptibility to antibacterials was tested on diluted Mueller-Hinton by using an agar dilution MIC method and a disk diffusion method. The COWT values calculated by Normalised Resistance Interpretation (NRI analysis allow isolates to be categorized either as wild-type fully susceptible (WT or as manifesting reduced susceptibility (NWT. When MIC data was used, NRI analysis calculated a COWT of ≤ 0.125 μg mL-1, ≤ 2 μg mL-1 and ≤ 0.5 μg mL-1 for amoxicillin, florfenicol and oxytetracycline, respectively. For the quinolones, the COWT were ≤1 μg mL-1, ≤ 0.5 μg mL-1 and ≤ 0.125 μg mL-1 for oxolinic acid, flumequine and enrofloxacin respectively. The disc diffusion data sets obtained in this work were extremely diverse and were spread over a wide range. For the quinolones there was a close agreement between the frequencies of NWT isolates calculated using MIC and disc data. For oxolinic acid, flumequine and enrofloxacin the frequencies were 45, 39 and 38% using MIC data, and 42, 41 and 44%, when disc data were used. There was less agreement with the other antimicrobials, because NWT frequencies obtained using MIC and disc data respectively, were 24% and 10% for amoxicillin, 8% and 2% for florfenicol and 70% and 64% for oxytetracycline. Considering that the MIC data was more precise than the disc diffusion data, MIC determination would be the preferred method for susceptibility testing for this species and the NWT frequencies

  16. Occurrence of motile Aeromonas in municipal drinking water and distribution of genes encoding virulence factors.

    Science.gov (United States)

    Pablos, Manuel; Rodríguez-Calleja, Jose M; Santos, Jesús A; Otero, Andrés; García-López, María-Luisa

    2009-10-31

    Aeromonas-associated cases of gastroenteritis are generally considered waterborne. The purpose of this study was to evaluate the potential microbiological risk associated with the presence of these bacteria in public drinking water. Over a period of one year, 132 drinking-water samples were monitored in León (NW of Spain, 137,000 inhabitants) for mandatory drinking-water standards and the occurrence of Aeromonas spp. Samples were taken at the municipal water treatment plant, one storage facility, and two public artesian drinking-water fountains. Because of low numbers of coliforms or Clostridium perfringens, the non-compliance rate with microbial standards was 3.8% whereas the percentage of positive samples for motile mesophilic Aeromonas was 26.5%. For all but two samples, Aeromonas was recovered between October and early March when the temperature was below 14 degrees C and the residual chlorine ranged from 0.21 to 0.72 mg/l. An apparent relationship was observed between rainfall and the incidence of Aeromonas. The 35 selected Aeromonas isolates were identified as A. caviae and A. media. The alt and laf genes were present in all isolates, the aerA gene was present in six isolates, and the four remaining genes investigated (hlyA, ast, stx1 and stx2) were absent. The combinations of putative virulence genes were: aerA(-)/hlyA(-)/alt(+)/ast(-)/laf(+)/stx1(-)/stx2(-) (82.9%) and aerA(+)/hlyA(-)/alt(+)/ast(-)/laf(+)/stx1(-)/stx2(-) (17.1%). None of the isolates bore plasmids. As Aeromonas strains harbouring two or more virulence-associated genes have the potential to cause disease by direct transmission via drinking water or by water use in food preparation, it would be advisable to control excessive numbers of these bacteria in drinking-water supplies.

  17. A genomic survey of the fish parasite Spironucleus salmonicida indicates genomic plasticity among diplomonads and significant lateral gene transfer in eukaryote genome evolution

    Directory of Open Access Journals (Sweden)

    Logsdon John M

    2007-02-01

    Full Text Available Abstract Background Comparative genomic studies of the mitochondrion-lacking protist group Diplomonadida (diplomonads has been lacking, although Giardia lamblia has been intensively studied. We have performed a sequence survey project resulting in 2341 expressed sequence tags (EST corresponding to 853 unique clones, 5275 genome survey sequences (GSS, and eleven finished contigs from the diplomonad fish parasite Spironucleus salmonicida (previously described as S. barkhanus. Results The analyses revealed a compact genome with few, if any, introns and very short 3' untranslated regions. Strikingly different patterns of codon usage were observed in genes corresponding to frequently sampled ESTs versus genes poorly sampled, indicating that translational selection is influencing the codon usage of highly expressed genes. Rigorous phylogenomic analyses identified 84 genes – mostly encoding metabolic proteins – that have been acquired by diplomonads or their relatively close ancestors via lateral gene transfer (LGT. Although most acquisitions were from prokaryotes, more than a dozen represent likely transfers of genes between eukaryotic lineages. Many genes that provide novel insights into the genetic basis of the biology and pathogenicity of this parasitic protist were identified including 149 that putatively encode variant-surface cysteine-rich proteins which are candidate virulence factors. A number of genomic properties that distinguish S. salmonicida from its human parasitic relative G. lamblia were identified such as nineteen putative lineage-specific gene acquisitions, distinct mutational biases and codon usage and distinct polyadenylation signals. Conclusion Our results highlight the power of comparative genomic studies to yield insights into the biology of parasitic protists and the evolution of their genomes, and suggest that genetic exchange between distantly-related protist lineages may be occurring at an appreciable rate in eukaryote

  18. Identification of clinical aeromonas species by rpoB and gyrB sequencing and development of a multiplex PCR method for detection of Aeromonas hydrophila, A. caviae, A. veronii, and A. media.

    Science.gov (United States)

    Persson, Søren; Al-Shuweli, Suzan; Yapici, Seval; Jensen, Joan N; Olsen, Katharina E P

    2015-02-01

    Conventional identification of Aeromonas species based on biochemical methods is challenged by the heterogeneous nature of the species. Here, we present a new multiplex PCR method directed toward the gyrB and rpoB genes that identifies four Aeromonas species, A. hydrophila, A. media, A. veronii, and A. caviae, and we describe the application of this method on a Danish strain collection.

  19. Aeromonas sp.F3胶原酶性质的研究%Characteristies of collagenase from Aeromonas sp.F3

    Institute of Scientific and Technical Information of China (English)

    白杨; 钱斯日古楞; 王红英; 马蕾

    2011-01-01

    Aeromonas sp. F3 was screened from marine mud for hydrolyzing collagen. The characteristics of collagenase from Aeromonas sp. F3 were investigated via single-factor test. Thermal treatment at 50 ℃ for 40 min resulted in obvious deactivation. The optimum reaction temperature and pH was 40 ℃ and 8. 6. Collagenase activity was activated by Ca2+ at 0. 5 mmol/L. The molecular weight of the hydrolyzate was under 30 ku.%海洋污泥中筛选得到的Aeromonas sp.F3所产的胞外酶对胶原蛋白有水解作用.以海洋微生物Aeromonas sp.F3为酶源,采用单因素试验法对其所产的胶原酶性质进行了研究,包括该胶原酶的酶解条件及热稳定性,并对该胶原酶水解鱼皮的效果进行了分析.结果表明,微生物Aeromonas sp.F3源胶原酶在50℃热处理40 min之后明显失活,该胶原酶的最适反应温度为40℃,最适pH为8.6,金属离子Ca2在0.5 mmol/L时对酶有激活作用.该酶在其最适条件下,对鱼皮胶原有显著水解效能,其水解产物的分子质量在30 ku以下.

  20. Identification and molecular characterization of the homogentisate pathway responsible for pyomelanin production, the major melanin constituents in Aeromonas media WS.

    Science.gov (United States)

    Wang, He; Qiao, Yunqian; Chai, Baozhong; Qiu, Chenxi; Chen, Xiangdong

    2015-01-01

    The pigmentation of many Aeromonas species has been thought to be due to the production of a L-DOPA (L-3,4-dihydroxyphenylalanine) based melanin. However, in this study we found that although L-DOPA synthesis occurs in the high-melanin-yielding Aeromonas media strain WS, it plays a minor, if any, role in pigmentation. Instead, the pigmentation of A. media strain WS is due to the production of pyomelanin through HGA (homogentisate). Gene products of phhA (encodes phenylalanine hydroxylase), tyrB and aspC (both encode aromatic amino acid aminotransferase), and hppD (encodes 4-hydroxyphenylpyruvate dioxygenase) constitute a linear pathway of converting phenylalanine to HGA and disruption of any one of these genes impairs or blocks pigmentation of A. media strain WS. This HGA biosynthesis pathway is widely distributed in Aeromonas, but HGA is only detectable in the cultures of pigmented Aeromonas species. Heterologous expression of HppD from both pigmented and non-pigmented Aeromonas species in E. coli leads to the production of pyomelanin and thus pigmentation, suggesting that most Aeromonas species have the critical enzymes to produce pyomelanin through HGA. Taken together, we have identified a widely conserved biosynthesis pathway of HGA based pyomelanin in Aeromonas that may be responsible for pigmentation of many Aeromonas species.

  1. AQU-1, a chromosomal class C β-lactamase, among clinical Aeromonas dhakensis isolates: distribution and clinical significance.

    Science.gov (United States)

    Wu, Chi-Jung; Wang, Hsuan-Chen; Chen, Po-Lin; Chang, Ming-Chung; Sunny Sun, H; Chou, Pei-Hsin; Ko, Wen-Chien

    2013-11-01

    Aeromonas dhakensis, a recently described Aeromonas sp. formerly called Aeromonas aquariorum, is associated with human infections. In this study, a chromosomal gene, blaAQU-1, was identified in A. dhakensis AAK1 that constitutes a 1143-bp open reading frame and is 87% identical to the gene encoding CepH in Aeromonas hydrophila. An Escherichia coli TOP10 cell transformant harbouring blaAQU-1 was resistant to cefotaxime but not to cefepime. mRNA expression of blaAQU-1 in the cefotaxime-resistant mutant strain AAK1m was 70-fold higher than in the wild strain AAK1. In all 16 A. dhakensis isolates (the major species of 51 consecutive Aeromonas blood isolates collected from June 1999 to June 2001) as well as in A. aquariorum MDC47(T) and A. hydrophila subsp. dhakensis LMG 19562(T), but not in the reference strains or clinical isolates of other A. hydrophila subspecies, Aeromonas caviae, Aeromonas veronii or Aeromonas enteropelogenes, blaAQU-1-related genes were detected by PCR. Overall, 13 (81%) of the 16 A. dhakensis blood isolates exhibited either cefotaxime resistance or the in vitro emergence of derepressed cefotaxime-resistant mutants. In vivo selection of an A. dhakensis resistant mutant was noted in a burn patient undergoing cefotaxime monotherapy. These observations suggest that AQU-1 is a chromosomal cephalosporinase in A. dhakensis. Cefotaxime monotherapy for severe A. dhakensis infections should be used cautiously.

  2. A prospective study on Aeromonas in outpatients with diarrhea in the central region of Rio Grande do Sul State

    Directory of Open Access Journals (Sweden)

    Karoline de Campos Prediger

    2012-09-01

    Full Text Available Aeromonas spp. were identified in five (2,7% of 182 diarrheal stool cultures, A. caviae was predominant, resistant mainly to ampicillin and cephalotin. This is the first study showing the presence of Aeromonas spp. in diarrheal stools of outpatients in the central region of Rio Grande do Sul State, Brazil.

  3. Identification and molecular characterization of the homogentisate pathway responsible for pyomelanin production, the major melanin constituents in Aeromonas media WS.

    Directory of Open Access Journals (Sweden)

    He Wang

    Full Text Available The pigmentation of many Aeromonas species has been thought to be due to the production of a L-DOPA (L-3,4-dihydroxyphenylalanine based melanin. However, in this study we found that although L-DOPA synthesis occurs in the high-melanin-yielding Aeromonas media strain WS, it plays a minor, if any, role in pigmentation. Instead, the pigmentation of A. media strain WS is due to the production of pyomelanin through HGA (homogentisate. Gene products of phhA (encodes phenylalanine hydroxylase, tyrB and aspC (both encode aromatic amino acid aminotransferase, and hppD (encodes 4-hydroxyphenylpyruvate dioxygenase constitute a linear pathway of converting phenylalanine to HGA and disruption of any one of these genes impairs or blocks pigmentation of A. media strain WS. This HGA biosynthesis pathway is widely distributed in Aeromonas, but HGA is only detectable in the cultures of pigmented Aeromonas species. Heterologous expression of HppD from both pigmented and non-pigmented Aeromonas species in E. coli leads to the production of pyomelanin and thus pigmentation, suggesting that most Aeromonas species have the critical enzymes to produce pyomelanin through HGA. Taken together, we have identified a widely conserved biosynthesis pathway of HGA based pyomelanin in Aeromonas that may be responsible for pigmentation of many Aeromonas species.

  4. Molecular detection and antimicrobial resistance of Aeromonas from houseflies (Musca domestica in Iran

    Directory of Open Access Journals (Sweden)

    Davood Ommi

    2015-11-01

    Full Text Available Objective. This study aimed to report the molecular detection and antimicrobial resistance of Aeromonas among houseflies (Musca domestica in Shahrekord and Isfahan provinces of Iran. Materials and methods. Flies were caught from household kitchens, cattle farms, animal hospitals, human hospitals, slaughter house and poultry farms and put in collection separate sterile tubes. Isolation was accomplished by culture of flies in alkaline peptone water followed by identification with Aeromonas-specific Polymerase Chain Reaction (PCR. Results. Out of 600 houseflies 73 (12.2% were infected with Aeromonas spp. Significantly higher frequencies of Aeromonas were isolated in Shahrekord province (13.0%; 39/300 than in Isfahan province (11.3%; 34/300. The recovery frequencies of the organisms were significantly lower in kitchens as compared to those in cattle farms and hospital wards which were similar. Higher proportions of infected flies were obtained during summer whereas low proportions were obtained during winter. Conclusions. It is concluded that houseflies do harbor diarrheagenic pathogens, including Aeromonas especially during summer. The carried organisms are resistant to a number of antimicrobials at different levels. Thus, future plans aimed at stemming infections caused by these organisms should take flies into account. Control efforts of infections caused by this particular bacterium should therefore take into account Musca domestica.

  5. Immersion exposure of rainbow trout (Oncorhynchus mykiss) fry to wildtype Flavobacterium psychrophilum induces no mortality, but protects against later intraperitoneal challenge

    DEFF Research Database (Denmark)

    Lorenzen, Ellen; Brudeseth, B.E.; Wiklund, T.

    2010-01-01

    in high titres of non-attenuated isolates of F. psychrophilum, was able to induce immunity to a subsequent ip challenge. Immersion in live bacteria for 30 or 50 min caused no mortality and protected a major fraction of the fry against challenges 26 and 47 days later with RPS values of 88.2 and 60...... that the fry have to be vaccinated very early, i.e. around 0.2–0.5 g, where RTFS usually starts to give problems in the fish farms. Consequently, only oral or bath vaccines are relevant. Immersion of fry in inactivated or attenuated bacteria has resulted in RPS values of less than 50%. However, the results...... are biased by the fact that the fish have been challenged by intraperitoneal (ip) or subcutaneous (sc) injection against which an immersion/oral vaccine may not protect. Therefore, the present study was undertaken in order to investigate whether the presumably most potent immersion immunization, i.e. bathing...

  6. Ocorrência de bactérias do gênero Aeromonas em queijo-de-minas frescal artesanal Occurrence of the genus Aeromonas in minas frescal cheese

    Directory of Open Access Journals (Sweden)

    C.C.C. Bulhões

    2002-06-01

    Full Text Available Foram analisadas 160 amostras de queijo-de-minas frescal artesanal, adquiridas no comércio varejista dos municípios de Poços de Caldas - MG e Jaboticabal - SP, a fim de verificar a ocorrência de bactérias do gênero Aeromonas no produto. Oitenta e duas (51,2% encontravam-se contaminadas pelos microrganismos, com populações que variavam de 5,0×10³ a 4,0×10(5 UFC/grama. Foram identificadas as espécies Aeromonas hydrophila, Aeromonas caviae, Aeromonas schubertii, além de cepas consideradas atípicas. Os resultados evidenciam que bactérias do gênero Aeromonas podem ser veiculadas através do queijo tipo minas frescal artesanal e devem servir de alerta aos serviços de saúde pública.One hundred and sixty samples of homemade minas frescal cheese, obtained at the retail trade in the municipalities of Poços de Caldas-MG and Jaboticabal-SP, were analyzed for occurrence of the genus Aeromonas. Eighty two samples (51.2% were contaminated by these microorganisms with populations that ranged from 5.0 x 10³ to 4.0 x 10(5 CFU/g. The species Aeromonas hydrophila, Aeromonas caviae, Aeromonas schubertii, were identified, along with atypical strains. The results show that Aeromonas bacteria genus can be transmitted through the homemade minas frescal cheese and they should serve of alert to the public health services.

  7. Aeromonas spp. IN PRODUCTS OF ANIMAL ORIGIN AND DRINKING WATER OF GOIÂNIA-GO Aeromonas spp. EM PRODUTOS DE ORIGEM ANIMAL E EM ÁGUA DE CONSUMO DE GOIÂNIA - GO

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    Albenones José de Mesquita

    2007-09-01

    Full Text Available

    A total of 53 samples of products from animal origin and drinking water was examined for the presence of Aeromonas spp. Aeromonas occurred in 26.41% (14/53 of the samples. The raw products showed high frequency of contamination and relatively high count Aeromonas hydrophila was the dominating species, 57.5%, being followed of A. veroni (22.5%, A. sobria (17.5% and A. media (2.5%. None of the Aeromonas spp. was isolated from chlorinated or unchlorinated drinking water.

    KEY-WORDS: Aeromonas; animal origin products; drinking water.

    Um total de 53 amostras de produtos de origem animal e água de consumo foi examinado para se verificar a presença de Aeromonas spp. Desse total, 14/53 (26,41% amostras foram positivas para Aeromonas. Os produtos crus apresentaram maior freqüência de contaminação e contagem relativamente elevadas. A espécie Aeromonas hydrophila foi a mais freqüente (57,5%, seguida pelas espécies A. veroni (22,5%, A. sobria (17,5% e A. media (2,5%. Nenhuma amostra de água de consumo, clorada ou não clorada, mostrou-se positiva para Aeromonas ssp.

    PALAVRA-CHAVE: Aeromonas; produtos de origem animal; água de consumo.

  8. POTENSI TUMBUHAN BANGKAL (Nauclea Orientalis UNTUK PENGENDALIAN BAKTERI Aeromonas Hydrophila (POTENTIAL PLANT BANGKAL (Nauclea orientalis FOR CONTROL Aeromonas Hydrophila

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    Siti Aisiah

    2017-02-01

    Full Text Available Tujuan penelitian ini adalah didapatkan metode pengendalian penyakit yang disebabkan oleh bakteri Aeromonas hydrophila pada budi daya ikan yang ramah lingkungan. Dalam penelitian ini dilakukan uji sensitivitas terhadap bakteri A. hydrophila, uji minimal konsentrasi menghambat  bakteri A. hydrophila (uji MIC dan uji toksisitas terhadap ikan nila. Rancangan  yang digunakan untuk  uji toksisitas  adalah rancangan acak lengkap (RAL, dengan 4 perlakuan yaitu A  = Ikan disuntik dengan ekstrak bangkal konsentrasi 20%, B  = Ikan disuntik dengan ekstrak bangkal konsentrasi 40%,  C  = Ikan disuntik dengan ekstrak bangkal konsentrasi 80%, dan D  = Kontrol (ikan tidak disuntik, diulang sebanyak 3 kali. Perlakuan ini didapat dari hasil uji sensitivitas antibakteri bangkal yang mempunyai daya hambat dan daya bunuh paling besar terhadap bakteri A. hydrophila yaitu ekstrak daun bangkal dengan pelarut akuades. Pengujian MIC menunjukkan bahwa ekstrak bangkal-akuades memiliki daya hambat minimal  20 % terhadap aktivitas bakteri A. hydrophila. Hasil uji toksisitas yang dilakukan terhadap ikan nila dengan konsentrasi 20%, 40% dan 80%  mortalitas ikan nila dibawah 50 %. Pengamatan hematologis yaitu eretrosit, leokosit, plasma darah, hematokrit dan leokokrit pada masing-masing perlakuan sebagian besar masih berada dalam kisaran yang normal. Parameter kualitas air yaitu, kadar oksigen terlarut,  pH, amoniak, CO2 dan suhu masih dapat mendukung kehidupan normal ikan nila. The purpose of this study was obtained method of controlling diseases caused by Aeromonas hydrophila in fish farming is environmentally friendly. In this study the sensitivity of the test  A. hydrophila, a minimum test konsentari inhibiting A. hydrophila (MIC test and toxicity test on  tilapia. The design used for toxicity tests is completely randomized design with 4 treatments it A = Fish injected with extracts bangkal concentration of 20 %,  B = Fish injected with extracts bangkal

  9. Physiological control of amonabactin biosynthesis in Aeromonas hydrophila.

    Science.gov (United States)

    Barghouthi, S; Young, R; Arceneaux, J E; Byers, B R

    1989-01-01

    Amonabactin is a siderophore from Aeromonas hydrophila which is produced in two biologically active forms composed of the phenolate 2,3-dihydroxybenzoic acid (DHB), lysine, glycine, and either trytophan (amonabactin T) or phenylalanine (amonabactin P). Amonabactin biosynthetic mutants (generated by chemical mutagenesis) that either produced no amonabactin or overproduced the siderophore were isolated and identified on chrome azurol S siderophore detection agar. Amonabactin-negative mutants were of two categories. One type produced no phenolates and used exogenous DHB to synthesize amonabactin (both forms) while the other type excreted DHB but not amonabactin. This suggests an amonabactin biosynthetic pathway composed of two segments, one producing DHB and the other assembling amonabactin from DHB and the amino acids. Overproduction mutants used amonabactin poorly or not at all, indicating that they contained lesions in amonabactin utilization. Adding the analog D-tryptophan to wild-type A. hydrophila cultures reduced synthesis of both amonabactin T and amonabactin P and lengthened the lag phase in iron restricted medium. The tryptophan and phenylalanine forms of amonabactin may be synthesized by a single assembly pathway that contains a novel enzyme (sensitive to D-tryptophan) which inserts either tryptophan or phenylalanine into amonabactin.

  10. Enterobacter asburiae and Aeromonas hydrophila: soft tissue infection requiring debridement.

    Science.gov (United States)

    Koth, Kevin; Boniface, James; Chance, Elisha A; Hanes, Marina C

    2012-06-01

    Enterobacter asburiae and Aeromonas hydrophila are gram-negative bacilli that have been isolated in soil and water. Enterobacter asburiae can cause an array of diseases, and exposure to A hydrophila can cause soft tissue infections, including necrotizing faciitis.A healthy-appearing 22-year-old man presented with an innocuous soft tissue injury to his leg due to an all-terrain vehicle crash. He received intravenous antibiotics and was discharged with prophylactic oral antibiotics. After the rapid onset of high fevers (102°F-103°F) <24 hours postinjury, he returned to the emergency department. Emergent surgical debridement was performed, and broad-spectrum intravenous antibiotics were started. Fevers persisted, and the patient underwent repeat extensive surgical debridement and antibiotic bead placement <30 hours after the initial surgical debridement and broad-spectrum antibiotics. Intraoperative cultures found E asburiae and A hydrophila in the wound. Following a long course of antibiotics and a skin graft, he fully recovered and had no functional deficits 1 year postoperatively.Extensive research revealed that these organisms are rare in soft tissue infections. E asburiae is opportunistic but has not been reported as a primary wound organism, and A hydrophila infections have been reported following motor vehicle crashes involving wound contamination. At presentation, it is challenging to determine rare organisms in a timely fashion; however, emergent extensive surgical intervention of an accelerated aberrant disease process should be considered to avoid catastrophic outcomes.

  11. A molecular study on the prevalence and virulence potential of Aeromonas spp. recovered from patients suffering from diarrhea in Israel.

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    Yigal Senderovich

    Full Text Available BACKGROUND: Species of the genus Aeromonas are native inhabitants of aquatic environments and have recently been considered emerging human pathogens. Although the gastrointestinal tract is by far the most common anatomic site from which aeromonads are recovered, their role as etiologic agents of bacterial diarrhea is still disputed. Aeromonas-associated diarrhea is a phenomenon occurring worldwide; however, the exact prevalence of Aeromonas infections on a global scale is unknown. METHODOLOGY/PRINCIPAL FINDINGS: The prevalence and virulence potential of Aeromonas in patients suffering from diarrhea in Israel was studied using molecular methods. 1,033 diarrheal stools were sampled between April and September 2010 and Aeromonas species were identified in 17 (∼2% patients by sequencing the rpoD gene. Aeromonas species identity and abundance was: A. caviae (65%, A. veronii (29% and Aeromonas taiwanensis (6%. This is the first clinical record of A. taiwanensis as a diarrheal causative since its recent discovery from a wound infection in a patient in Taiwan. Most of the patients (77% from which Aeromonas species were isolated were negative for any other pathogens. The patients ranged from 1 to 92 years in age. Aeromonas isolates were found to possess different virulence-associated genes: ahpB (88%, pla/lip/lipH3/apl-1 (71%, act/hlyA/aerA (35%, alt (18%, ast (6%, fla (65%, lafA (41%, TTSS ascV (12%, TTSS ascF-ascG (12%, TTSS-dependent ADP-ribosylating toxins aexU (41% and aexT (6% in various combinations. Most of the identified strains were resistant to beta-lactam antibiotics but susceptible to third-generation cephalosporin antibiotics. CONCLUSIONS: Aeromonas may be a causative agent of diarrhea in patients in Israel and therefore should be included in routine bacteriological screenings.

  12. Aeromonas cavernicola sp. nov., isolated from fresh water of a brook in a cavern.

    Science.gov (United States)

    Martínez-Murcia, Antonio; Beaz-Hidalgo, Roxana; Svec, Pavel; Saavedra, Ma José; Figueras, Ma José; Sedlacek, Ivo

    2013-02-01

    Aeromonas P2973 was isolated from the water of a brook in a cavern in the Czech Republic. This isolate could not be biochemically identified at the species level, considering all updated species descriptions. Subsequent extensive phenotypic characterisation, DNA-DNA hybridisation, 16S rRNA gene sequencing and a Multi-Locus Phylogenetic Analysis (MLPA) of the concatenated sequence of 7 housekeeping genes (gyrB, rpoD, recA, dnaJ, gyrA, dnaX and atpD; 4705 bp) was employed in an attempt to ascertain the taxonomy of this isolate. Based on this polyphasic approach, we describe a novel species of the genus Aeromonas, for which the name Aeromonas cavernicola sp. nov. is proposed, with strain CCM7641(T) (DSM24474(T), CECT7862(T)) as the type strain.

  13. Molecular characterization of fluoroquinolone-resistant Aeromonas spp. isolated from imported shrimp.

    Science.gov (United States)

    Shakir, Zakiya; Khan, Saeed; Sung, Kidon; Khare, Sangeeta; Khan, Ashraf; Steele, Roger; Nawaz, Mohamed

    2012-11-01

    Sixty-three nalidixic acid-resistant Aeromonas sp. isolates were obtained from imported shrimp. Phylogenetic analysis of gyrB sequences indicated that 18 were A. enteropelogenes, 26 were A. caviae, and 19 were A. sobria. Double missense mutations in the quinolone resistance-determining region (QRDR) of gyrA at codon 83 (Ser→Val/Ile) and codon 92 (Leu→Met) coupled with a point mutation of parC at codon 80 (Ser→Ile/Phe) conferred high levels of quinolone resistance in the isolates. A majority of A. enteropelogenes and A. caviae strains harbored toxin genes, whereas only a few A. sobria strains harbored these genes. The fluoroquinolone-resistant Aeromonas spp. exhibited higher cytotoxicity than fluoroquinolone-sensitive, virulent Aeromonas spp. to rat epithelial cells.

  14. Evaluation of the MALDI-TOF MS profiling for identification of newly described Aeromonas spp.

    Science.gov (United States)

    Vávrová, Andrea; Balážová, Tereza; Sedláček, Ivo; Tvrzová, Ludmila; Šedo, Ondrej

    2015-09-01

    The genus Aeromonas comprises primarily aquatic bacteria and also serious human and animal pathogens with the occurrence in clinical material, drinking water, and food. Aeromonads are typical for their complex taxonomy and nomenclature and for limited possibilities of identification to the species level. According to studies describing the use of MALDI-TOF MS in diagnostics of aeromonads, this modern chemotaxonomical approach reveals quite high percentage of correctly identified isolates. We analyzed 64 Aeromonas reference strains from the set of 27 species. After extending the range of analyzed Aeromonas species by newly described ones, we proved that MALDI-TOF MS procedure accompanied by Biotyper tool is not a reliable diagnostic technique for aeromonads. We obtained quite high percentage of false-positive, incorrect, and uncertain results. The identification of newly described species is accompanied with misidentifications that were observed also in the case of pathogenic aeromonads.

  15. Phylogenetic diversity, antibiotic resistance and virulence traits of Aeromonas spp. from untreated waters for human consumption.

    Science.gov (United States)

    Carvalho, Maria João; Martínez-Murcia, Antonio; Esteves, Ana Cristina; Correia, António; Saavedra, Maria José

    2012-10-15

    It is well known that water constitutes an important contamination route for microorganisms. This is especially true for Aeromonas which are widespread in untreated and treated waters. In this study, Portuguese untreated waters not regularly monitored were screened for the presence and diversity of aeromonads. A total of 206 isolates were discriminated by RAPD-PCR and 80 distinct strains were identified by gyrB based phylogenetic analysis. The most frequently detected species were Aeromonas hydrophila, Aeromonas bestiarum and Aeromonas media. The antibiotic susceptibility profile of these strains was determined and showed a typical profile of the genus. Nonetheless, the percentage of resistant strains to tetracycline, chloramphenicol and/or trimethoprim/sulfamethoxazole was lower than that reported for clinical isolates and isolates recovered from aquacultures and other environments historically subjected to antibiotic contamination. This suggests that the existence of such pressures in those environments selects for resistant Aeromonas. A similar trend for integron presence was found. Genes coding for CphA and TEM, and tet(A), (E), (C) or (D) genes were found in 28%, 1%, and 10% of the strains, respectively. 10% of the strains contained an integron. Variable regions of seven class 1 integrons and one class 2 integron were characterised. Furthermore, strains displayed virulence related phenotypes such as extracellular lipolytic and proteolytic activities as well as aerolysin related genes (43% of strains). The ascV and aexT genes were found in 16% and 3% of strains respectively and, in some cases, concomitantly in the same specimen. This study shows that diverse Aeromonas spp. presenting distinct antibiotic resistance features and putative virulence traits are frequently present in waters for human and animal consumption in Portugal. Genes associated to antibiotic resistance and microbial virulence previously identified in organisms with human health significance

  16. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources

    OpenAIRE

    Olumide A. Odeyemi; Ahmad, Asmat

    2015-01-01

    This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13), bivalve (n = 10), sea cucumber (n = 16) and sea water (n = 14) and resistance to 12 antibiotics – Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole...

  17. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources

    OpenAIRE

    Olumide A. Odeyemi; Asmat Ahmad

    2017-01-01

    This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13), bivalve (n = 10), sea cucumber (n = 16) and sea water (n = 14) and resistance to 12 antibiotics – Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole...

  18. Levels of enzymes in leukaemic mice treated withAeromonas L-asparaginase.

    Science.gov (United States)

    Benny, P J; Muraleedhara Kurup, G; Sreejith, K

    1999-07-01

    L-asparaginase isolated in our laboratory fromAeromonas has been found to be antileukaemic. In the present study changes in the levels of serum enzymes in leukaemic mice and under treatment withAeromonas L-asparaginase has been compared. A significant increase in the levels of serum lactate dehydrogenase with tumour growth and a decrease during therapy was observed. A significant decrease in alanine transaminase activity during tumour growth and an increase during treatment was noticed. Increased levels of aspartate transaminase and alkaline phosphatase was observed during enzyme therapy. Total acid phosphatase was found to be increased during tumour growth and decreased considerably during treatment.

  19. Metabolism of proteins and glycoproteins in tumour bearing mice treated with Aeromonas L-asparaginase.

    Science.gov (United States)

    Benny, P J; Muraleedhara, K G; Sreejith, K; Jayashree, G

    1996-12-01

    L-asparaginase, isolated in our laboratory, from Aeromonas had been found to be antileukaemic. In the present study, changes in the levels of proteins and glycoproteins in leukaemic mice and under treatment with Aeromonas L-asparaginase have been compared. Levels of protein bound hexose, fucose and sialic acid which were increased during leukaemia attained normal levels when treated with L-asparaginase. The increased blood urea level declined significantly during enzyme therapy. Effects of L-asparaginase are compared with 'Leunase', a commercially available drug used in the treatment of leukaemia.

  20. Spontaneous aeromonas peritonitis%自发性气单胞菌腹膜炎

    Institute of Scientific and Technical Information of China (English)

    陆天雨

    2011-01-01

    自发性气单胞菌腹膜炎的发生在肝硬化腹水患者中并不罕见.本文就如何诊断及预防自发性气单胞菌腹膜炎,提高患者预后综述如下.%Spontaneous aeromonas peritonitis is a common complication in hepatocirrhosis patients with hepatic ascites.The aim of this review is to discuss how to diagnose and prevent spontaneous Aeromonas peritonitis.

  1. Properties of hemolysin and protease produced by Aeromonas trota.

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    Eizo Takahashi

    Full Text Available We examined the properties of exotoxins produced by Aeromonas trota (A. enteropelogenes, one of the diarrheagenic species of Aeromonadaceae. Nine of 19 A. trota isolates that grew on solid media containing erythrocytes showed hemolytic activity. However, the hemolytic activities of the culture supernatants of these hemolytic strains of A. trota were markedly lower than those of A. sobria when cultured in liquid medium, and the amount of hemolysin detected by immunoblotting using antiserum against the hemolysin produced by A. sobria was also low. A mouse intestine loop assay using living bacterial cells showed that A. trota 701 caused the significant accumulation of fluid, and antiserum against the hemolysin produced suppressed the enterotoxic action of A. trota 701. These results indicated that A. trota 701 was diarrheagenic and the hemolysin produced was the causative agent of the enterotoxic activity of A. trota. The hemolysin in A. sobria was previously shown to be secreted in a preform (inactive form and be activated when the carboxy-terminal domain was cleaved off by proteases in the culture supernatant. Since mature hemolysin was detected in the culture supernatants of A. trota, we analyzed the extracellular protease produced by A. trota. Fifteen of 19 A. trota isolates that grew on solid media containing skim milk showed proteolytic activity. We subsequently found that most A. trota isolates possessed the serine protease gene, but not the metalloprotease gene. Therefore, we determined the nucleotide sequence of the serine protease gene and its chaperone A. trota gene. The results obtained revealed that the deduced amino acid sequences of serine protease and the chaperone were homologous to those of A. sobria with identities of 83.0% and 75.8%, respectively.

  2. Molecular detection of the Aeromonas virulence aerolysin gene in retail meats from different animal sources in Egypt.

    Science.gov (United States)

    Osman, Kamelia; Aly, Magdy; Kheader, Afaf; Mabrok, Khaled

    2012-05-01

    Meat commonly contain the same Aeromonas spp. which occur in human diarrhoeal and non-diarrhoeal faecal samples. Motile Aeromonas were isolated from 5.6% of total 302 samples. The distribution of the isolates were 5.9 and 5.2% in fresh and frozen samples, respectively. Of the 302 samples taken of the four animal meat species investigated, the genus Aeromonas were isolated in 12.3% of the fresh samples collected from buffalo meat, in 6.5% of the samples collected from sheep meat and 14.0% from the samples collected from the cattle frozen meat samples. The camel meat did not reveal any Aeromonas isolates. Aeromonas hydrophila was isolated as the most prevalent species with 6.8%, followed by Aeromonas caviae with 2.7% and Aeromonas sobria with 2.1% from the total meat samples. Aerolysin toxin gene (aerA) was detected in 3/17 isolates of A. hydrophila isolated from contaminated meat. Infection due to bacterial pathogen with such virulent factor through contact with contaminated meat while handling them, poses health hazards to humans.

  3. Occurrence, molecular characterization, and antimicrobial susceptibility of Aeromonas spp. in marine species of shrimps cultured at inland low salinity ponds.

    Science.gov (United States)

    Yano, Yutaka; Hamano, Kaoru; Tsutsui, Isao; Aue-Umneoy, Dusit; Ban, Masatoshi; Satomi, Masataka

    2015-05-01

    We aimed to document the risk of Aeromonas spp. in marine shrimp species cultured in inland low salinity ponds in Thailand. In 14 of 18 shrimp samples retrieved from inland grow-up ponds, Aeromonas spp. were detected at ranges from 4667 to 1,500,000 CFU/g body weight. The phylogenetic tree constructed with the gyrB and cpn60 concatenated sequences indicated that the 87 isolates consisted of Aeromonas veronii (70%), Aeromonas aquariorum (18%), Aeromonas caviae (7%), Aeromonas jandaei (2%), and Aeromonas schubertii (2%). The potential virulence of the isolates was examined by phenotypic and PCR assays. Hemolytic activity and the extracellular activity of lipase, DNase, and gelatinase were observed in most isolates (94-99%). PCR revealed the presence of 9 genes related to virulence in the 87 isolates: act (75%), aer (74%), alt (30%), ast (1%), ascV (34%), aexT (24%), fla (92%), ela (34%), and lip (24%). The susceptibility profiles to 14 antimicrobial agents of isolates were typical for the genus, but resistance to cefotaxime, a third-generation cephalosporin, and imipenem were found in two A. aquariorum and in three A. veronii isolates, respectively. These resistances were confirmed by determining minimum inhibitory concentrations. Our results indicate that the microbiological risk posed by Aeromonas should be considered for marine shrimp species that are cultured in low-salinity ponds. These shrimps may also be a vehicle for the transfer of different genotypes of Aeromonas and antibiotic-resistant determinants to regions worldwide through trade.

  4. A mutant in one of two exbD loci of a TonB system in Flavobacterium psychrophilum shows attenuated virulence and confers protection against cold water disease.

    Science.gov (United States)

    Alvarez, Beatriz; Alvarez, Javier; Menéndez, Aurora; Guijarro, José A

    2008-04-01

    Flavobacterium psychrophilum is a psychrotrophic fish-pathogenic bacterium that causes cold water disease (CWD) in salmonids. By means of Tn4351 mutagenesis a mutant named FP1033, deficient in growth on iron-depleted medium, was previously isolated. FP1033 recovered the parental phenotype in the presence of iron. The gene disrupted by the transposon in this mutant encoded a protein with similarity to ExbD proteins, which are members of the TonB complex system involved in iron uptake mediated by siderophores. Analysis of the DNA surrounding the transposon insertion showed the presence of a tonB cluster of genes composed of exbB, two exbD (exbD1 and exbD2) and tonB loci. RT-PCR analysis and complementation studies indicated that these genes are transcribed as an operon and that the exbD2 : : Tn4351 phenotype was caused by the lack of ExbD2. FP1033 showed decreased virulence and conferred a high level of protection in rainbow trout fry after vaccination. This is believed to be the first report of a F. psychrophilum attenuated strain that induces a protective immune response in rainbow trout against CWD. These results suggest that the exbD2 locus from this particular TonB system is a suitable target to generate a live attenuated vaccine.

  5. Draft Genome Sequences of Three Aeromonas hydrophila Isolates from Catfish and Tilapia

    Science.gov (United States)

    Tekedar, Hasan C.; Kumru, Salih; Kalindamar, Safak; Karsi, Attila; Waldbieser, Geoffrey C.; Sonstegard, Tad; Schroeder, Steven G.; Liles, Mark R.; Griffin, Matt J.

    2017-01-01

    ABSTRACT Aeromonas hydrophila is a Gram-negative bacterium that is particularly adapted to freshwater environments and can cause severe infections in fish and humans. Here, we report the draft genomes of three A. hydrophila catfish and tilapia isolates. PMID:28104665

  6. Active Shiga-like toxin produced by some Aeromonas spp., isolated in Mexico City

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    Ingrid Palma-Martínez

    2016-09-01

    Full Text Available Shiga-like toxins (Stx represent a group of bacterial toxins involved in human and animal diseases. Stx is produced by enterohemorrhagic Escherichia coli, Shigella dysenteriae type 1, Citrobacter freundii and Aeromonas spp. Stx is an important cause of bloody diarrhea and hemolytic uremic syndrome (HUS. The aim of this study was to identify the stx1/stx2 genes in clinical strains and in outer membrane vesicles (OMVs of Aeromonas spp., 66 strains were isolated from children who live in Mexico City and Shiga-like toxins effects were evaluated on Vero cell cultures.The capacity to express active, Stx1 and Stx2 toxins was determined on Vero cell cultures and the concentration of Shiga-like toxins was evaluated by lethal dose to 50% (LD50 assays, observing inhibition of damaged cells by specific monoclonal antibodies. The results obtained in this study support the hypothesis that the stx gene is another putative virulence factor of Aeromonas, and since this gene can be transferred horizontally through OMVs this genus should be included as a possible causal agents of gastroenteritis and it should be reported as part of standard health surveillance procedures.Furthermore, these results indicate that Aeromonas genus might be a potential causative agent of HUS.

  7. Molecular characterization of Aeromonas spp. and Vibrio cholerae O1 isolated during a diarrhea outbreak

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    Carina Lucena Mendes-Marques

    2012-12-01

    Full Text Available This work aimed to assess pathogenic potential and clonal relatedness of Aeromonas sp. and Vibrio cholerae isolates recovered during a diarrhea outbreak in Brazil. Clinical and environmental isolates were investigated for the presence of known pathogenic genes and clonal relatedness was assessed by intergenic spacer region (ISR 16S-23S amplification. Four Aeromonas genes (lip, exu, gcat, flaA/B were found at high overall frequency in both clinical and environmental isolates although the lip gene was specifically absent from selected species. A fifth gene, aerA, was rarely found in A. caviae, the most abundant species. The ISR profile revealed high heterogeneity among the Aeromonas isolates and no correlation with species identification. In contrast, in all the V. cholerae isolates the four genes investigated (ctxA, tcpA, zot and ace were amplified and revealed homogeneous ISR and RAPD profiles. Although Aeromonas isolates were the major enteric pathogen recovered, their ISR profiles are not compatible with a unique cause for the diarrhea events, while the clonal relationship clearly implicates V. cholerae in those cases from which it was isolated. These results reinforce the need for a better definition of the role of aeromonads in diarrhea and whether they benefit from co-infection with V. cholerae.

  8. Antibiotic Susceptibility Profile of Aeromonas Species Isolated from Wastewater Treatment Plant

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    Isoken H. Igbinosa

    2012-01-01

    Full Text Available This study assessed the prevalence of antibiotic-resistant Aeromonas species isolated from Alice and Fort Beaufort wastewater treatment plant in the Eastern Cape Province of South Africa. Antibiotic susceptibility was determined using the disc diffusion method, and polymerase chain reaction (PCR assay was employed for the detection of antibiotics resistance genes. Variable susceptibilities were observed against ciprofloxacin, chloramphenicol, nalidixic acid, gentamicin, minocycline, among others. Aeromonas isolates from both locations were 100% resistant to penicillin, oxacillin, ampicillin, and vancomycin. Higher phenotypic resistance was observed in isolates from Fort Beaufort compared to isolates from Alice. Class A pse1 β-lactamase was detected in 20.8% of the isolates with a lower detection rate of 8.3% for blaTEM gene. Class 1 integron was present in 20.8% of Aeromonas isolates while class 2 integron and TetC gene were not detected in any isolate. The antibiotic resistance phenotypes observed in the isolates and the presence of β-lactamases genes detected in some isolates are of clinical and public health concern as this has consequences for antimicrobial chemotherapy of infections associated with Aeromonas species. This study further supports wastewater as potential reservoirs of antibiotic resistance determinants in the environment.

  9. Diversity and antibiotic resistance of Aeromonas spp. in drinking and waste water treatment plants.

    Science.gov (United States)

    Figueira, Vânia; Vaz-Moreira, Ivone; Silva, Márcia; Manaia, Célia M

    2011-11-01

    The taxonomic diversity and antibiotic resistance phenotypes of aeromonads were examined in samples from drinking and waste water treatment plants (surface, ground and disinfected water in a drinking water treatment plant, and raw and treated waste water) and tap water. Bacteria identification and intra-species variation were determined based on the analysis of the 16S rRNA, gyrB and cpn60 gene sequences. Resistance phenotypes were determined using the disc diffusion method. Aeromonas veronii prevailed in raw surface water, Aeromonas hydrophyla in ozonated water, and Aeromonas media and Aeromonas puntacta in waste water. No aeromonads were detected in ground water, after the chlorination tank or in tap water. Resistance to ceftazidime or meropenem was detected in isolates from the drinking water treatment plant and waste water isolates were intrinsically resistant to nalidixic acid. Most of the times, quinolone resistance was associated with the gyrA mutation in serine 83. The gene qnrS, but not the genes qnrA, B, C, D or qepA, was detected in both surface and waste water isolates. The gene aac(6')-ib-cr was detected in different waste water strains isolated in the presence of ciprofloxacin. Both quinolone resistance genes were detected only in the species A. media. This is the first study tracking antimicrobial resistance in aeromonads in drinking, tap and waste water and the importance of these bacteria as vectors of resistance in aquatic environments is discussed.

  10. Cold Shock Exoribonuclease R (VacB) is Involved in Aeromonas hydrophila Pathogenesis

    Science.gov (United States)

    In this study, we cloned and sequenced a virulence-associated gene (vacB) from a clinical isolate SSU of Aeromonas hydrophila. We identified this gene based on our recently annotated genome sequence of the environmental isolate ATCC 7966T of A. hydrophila and the vacB gene of Shi...

  11. Cold Shock Exoribonuclease R(VacB) is involved in Aeromonas hydrophila Virulence

    Science.gov (United States)

    In this study, we cloned and sequenced a virulence-associated gene (vacB) from a clinical isolate SSU of Aeromonas hydrophila. We identified this gene based on our recently annotated genome sequence of the environmental isolate ATCC 7966T of A. hydrophila and the vacB gene of Shi...

  12. Cold Shock Exoribonuclease R(VacB) is involved in Aeromonas hydrophila Virulence

    Science.gov (United States)

    In this study, we cloned and sequenced a virulence-associated gene (vacB) from a clinical isolate SSU of Aeromonas hydrophila. We identified this gene based on our recently annotated genome sequence of the environmental isolate ATCC 7966T of A. hydrophila and the vacB gene of Shi...

  13. Cold Shock Exoribonuclease R (VacB) is Involved in Aeromonas hydrophila Pathogenesis

    Science.gov (United States)

    In this study, we cloned and sequenced a virulence-associated gene (vacB) from a clinical isolate SSU of Aeromonas hydrophila. We identified this gene based on our recently annotated genome sequence of the environmental isolate ATCC 7966T of A. hydrophila and the vacB gene of Shi...

  14. Draft genome sequences of four virulent aeromonas hydrophila strains from catfish aquaculture

    Science.gov (United States)

    Since 2009, a clonal group of virulent Aeromonas hydrophila (VAh) strains has been causing severe disease in the catfish aquaculture industry in the Southeastern United States. Here, we report draft genomes of four A. hydrophila isolates from catfish aquaculture that represent this clonal group....

  15. Active Shiga-Like Toxin Produced by Some Aeromonas spp., Isolated in Mexico City

    Science.gov (United States)

    Palma-Martínez, Ingrid; Guerrero-Mandujano, Andrea; Ruiz-Ruiz, Manuel J.; Hernández-Cortez, Cecilia; Molina-López, José; Bocanegra-García, Virgilio; Castro-Escarpulli, Graciela

    2016-01-01

    Shiga-like toxins (Stx) represent a group of bacterial toxins involved in human and animal diseases. Stx is produced by enterohemorrhagic Escherichia coli, Shigella dysenteriae type 1, Citrobacter freundii, and Aeromonas spp.; Stx is an important cause of bloody diarrhea and hemolytic uremic syndrome (HUS). The aim of this study was to identify the stx1/stx2 genes in clinical strains and outer membrane vesicles (OMVs) of Aeromonas spp., 66 strains were isolated from children who live in Mexico City, and Stx effects were evaluated in Vero cell cultures. The capacity to express active Stx1 and Stx2 toxins was determined in Vero cell cultures and the concentration of Stx was evaluated by 50% lethal dose (LD50) assays, observing inhibition of damaged cells by specific monoclonal antibodies. The results obtained in this study support the hypothesis that the stx gene is another putative virulence factor of Aeromonas, and since this gene can be transferred horizontally through OMVs this genus should be included as a possible causal agents of gastroenteritis and it should be reported as part of standard health surveillance procedures. Furthermore, these results indicate that the Aeromonas genus might be a potential causative agent of HUS. PMID:27725813

  16. A Mouse Model for Characterization of Gastrointestinal Colonization Rates Among Environmental Aeromonas Isolates

    Science.gov (United States)

    The colonization rates of ten different environmental isolates of Aeromonas were determined using a novel mouse-streptomycin pre-treatment method. A novel streptomycin pre-treatment prepared animals with a transient alteration in colon flora that allowed colonization by Aeromon...

  17. Immunization with recombinant aerolysin and hemolysin protected channel catfish against virulent Aeromonas hydrophila

    Science.gov (United States)

    Aeromonas hydrophila is emerging as one of the major concerns in catfish aquaculture in the Southeastern United States due to recent outbreaks of motile aeromonad septicemia (MAS) caused by virulent clonal isolates. There is no effective vaccine currently available for the prevention of MAS. In this...

  18. Virulence and antimicrobial susceptibility of clinical and environmental strains of Aeromonas spp. from northeastern Brazil.

    Science.gov (United States)

    Castelo-Branco, Débora de Souza Collares Maia; Guedes, Glaucia Morgana de Melo; Brilhante, Raimunda Sâmia Nogueira; Rocha, Marcos Fábio Gadelha; Sidrim, José Júlio Costa; Moreira, José Luciano Bezerra; Cordeiro, Rossana de Aguiar; Sales, Jamille Alencar; Riello, Giovanna Barbosa; de Alencar, Lucas Pereira; Paiva, Manoel de Araújo Neto; Vasconcelos, David Caldas; de Menezes, Isis Sousa Bezerra; de Ponte, Yago Brito; Sampaio, Célia Maria de Souza; Monteiro, André Jalles; Bandeira, Tereza de Jesus Pinheiro Gomes

    2015-08-01

    The aims of the present study were to isolate and identify clinical and environmental strains of Aeromonas spp. by means of biochemical tests and the automated method VITEK 2 and to investigate the presence of the virulence genes cytotoxic enterotoxin (act), hemolysin (asa-1), and type III secretion system (ascV), and also the in vitro antimicrobial susceptibility of the strains. From the clinical isolates, 19 Aeromonas hydrophila, 3 Aeromonas veronii bv. sobria, and 1 Aeromonas caviae were identified, while from the environmental strains, 11 A. hydrophila, 22 A. veronii bv. sobria, 1 A. veronii bv. veronii, and 1 A. caviae were recovered. The gene act was detected in 69.5% of clinical isolates, asa-1 in 8.6%, and ascV in 34.7%. In the environmental strains, the detection rates were 51.4%, 45.7%, and 54.2% for the genes act, asa-1, and ascV, respectively. Resistance to amoxicillin-clavulanate and piperacillin-tazobactam was observed in 15 and 3 clinical strains, respectively, and resistance to ceftazidime, meropenem, imipenem, ciprofloxacin, and trimethoprim-sulfamethoxazole was observed in 1 strain for each drug. Resistance to amoxicillin-clavulanate and piperacillin-tazobactam was detected in 17 and 1 environmental strain, respectively. Higher resistance percentages were observed in clinical strains, but environmental strains also showed this phenomenon and presented a higher detection rate of virulence genes. Thus, it is important to monitor the antimicrobial susceptibility and pathogenic potential of the environmental isolates.

  19. Function of a recombinant Chitinase derived from a virulent Aeromonas hydrophila isolated from diseased channel catfish

    Science.gov (United States)

    A chitinase was identified in extracellular products of a virulent Aeromonas hydrophila isolated from diseased channel catfish (Ictalurus punctatus). Bioactive recombinant chitinase (rChi-Ah) was produced in Escherichia coli. Purified rChi-Ah had optimal activity at temperature of 42°C and pH 6.5. T...

  20. Virulence diversity among bacteremic Aeromonas isolates: ex vivo, animal, and clinical evidences.

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    Po-Lin Chen

    Full Text Available BACKGROUND: The objective of this study was to compare virulence among different Aeromonas species causing bloodstream infections. METHODOLOGY/PRINCIPAL FINDINGS: Nine of four species of Aeromonas blood isolates, including A. dhakensis, A. hydrophila, A. veronii and A. caviae were randomly selected for analysis. The species was identified by the DNA sequence matching of rpoD. Clinically, the patients with A. dhakensis bacteremia had a higher sepsis-related mortality rate than those with other species (37.5% vs. 0%, P = 0.028. Virulence of different Aeromonas species were tested in C. elegans, mouse fibroblast C2C12 cell line and BALB/c mice models. C. elegans fed with A. dhakensis and A. caviae had the lowest and highest survival rates compared with other species, respectively (all P values <0.0001. A. dhakensis isolates also exhibited more cytotoxicity in C2C12 cell line (all P values <0.0001. Fourteen-day survival rate of mice intramuscularly inoculated with A. dhakensis was lower than that of other species (all P values <0.0001. Hemolytic activity and several virulence factor genes were rarely detected in the A. caviae isolates. CONCLUSIONS/SIGNIFICANCE: Clinical data, ex vivo experiments, and animal studies suggest there is virulence variation among clinically important Aeromonas species.

  1. Molecular characterization of Aeromonas species isolated from farmed eels (Anguilla japonica).

    Science.gov (United States)

    Yi, Seung-Won; You, Myung-Jo; Cho, Ho-Seong; Lee, Chang-Seop; Kwon, Joong-Ki; Shin, Gee-Wook

    2013-05-31

    Seventy Aeromonas strains were identified by phylogenetic analysis using housekeeping genes (gyrB and rpoD) in order to investigate etiological agents for aeromoniasis in farmed eels (Anguilla japonica). The phylogenetic analysis showed that Aeromonas aquariorum (n=22, 31.4%) was the predominant species among the investigated eel strains, followed by Aeromonas caviae (n=16, 22.9%), A. veronii (n=13, 18.6%), A. hydrophila (n=12, 17.1%), A. jandaei (n=4, 5.7%), A. media (n=2, 2.9%), and A. trota (n=1, 1.4%). The potential virulence of the present strains was estimated by performing PCR assays using the following seven virulence genes: cytotoxic enterotoxin (act), two cytotonic enterotoxins (alt and ast), glycerophospholipid:cholesterol acyltransferase (gcaT), DNase (exu), lipase (lip), and flagellin (fla). The detection rates of act, alt, ast, gcaT, exu, lip, and fla among all 70 strains were 91.4%, 55.7%, 27.1%, 97.1%, 95.7%, 100%, and 98.6%, respectively. In genotyping of enterotoxin genes, act(+)/alt(+)/ast(+), act(+)/alt(+)/ast(-), and act(+)/alt(-)/ast(-) genotypes were prevalent in A. hydrophila (8/12 strains), A. aquariorum (13/22 strains), and A. caviae (14/16 strains), respectively, suggesting a high heterogeneity among Aeromonas species. In this study, A. aquariorum, which has been an unrecorded species in Korea, can be an etiological agent for aeromoniasis of eel.

  2. Molecular characterization of a functional type VI secretion system from a clinical isolate of Aeromonas hydrophila

    Science.gov (United States)

    Our laboratory recently molecularly characterized the type II secretion system (T2SS)-associated cytotoxic enterotoxin (Act) and the T3SS-secreted AexU effector from a diarrheal isolate SSU of Aeromonas hydrophila. The role of these toxin proteins in the pathogenesis of A. hydrop...

  3. Draft Genome Sequence of Marine-Derived Aeromonas caviae CHZ306, a Potential Chitinase Producer Strain

    Science.gov (United States)

    Zimpel, Cristina Kraemer; Guimaraes, Ana Marcia Sa; Pessoa, Adalberto; Rivera, Irma Nelly Gutierrez

    2016-01-01

    We report here a draft genome sequence of Aeromonas caviae CHZ306, a marine-derived bacterium with the ability to hydrolyze chitin and express high levels of chitinases. The assembly resulted in 65 scaffolds with approximately 4.78 Mb. Genomic analysis revealed different genes encoding chitin-degrading enzymes that can be used for chitin derivative production. PMID:27856589

  4. Humoral immune response of catfish immunized with extracellular products of Aeromonas hydrophila

    Science.gov (United States)

    Aeromonas hydrophila is emerging as one of the major concerns in catfish aquaculture in the Southeastern United States due to recent outbreaks of motile aeromonad septicemia (MAS) caused by the pathogen. Prophylactic treatment is being sought to prevent MAS. Since multiple virulence associated facto...

  5. Detection and quantification of virulent Aeromonas hydrophila in channel catfish tissues following waterborne challenge

    Science.gov (United States)

    The aim of this study was to understand the pathogenesis of motile aeromonas septicemia caused by virulent A. hydrophila (vAh) in channel catfish, Ictalurus punctatus. Adipose fin clipped catfish were challenged with vAh using waterborne challenge method and the distribution of vAh in catfish tissue...

  6. Direct evidence of recombination in the recA gene of Aeromonas bestiarum.

    Science.gov (United States)

    Sanglas, Ariadna; Albarral, Vicenta; Farfán, Maribel; Lorén, J Gaspar; Fusté, M Carmen

    2016-03-01

    Two hundred and twenty-one strains representative of all Aeromonas species were characterized using the recA gene sequence, assessing its potential as a molecular marker for the genus Aeromonas. The inter-species distance values obtained demonstrated that recA has a high discriminatory power. Phylogenetic analysis, based on full-length gene nucleotide sequences, revealed a robust topology with clearly separated clusters for each species. The maximum likelihood tree showed the Aeromonas bestiarum strains in a well-defined cluster, containing a subset of four strains of different geographical origins in a deep internal branch. Data analysis provided strong evidence of recombination at the end of the recA sequences in these four strains. Intergenomic recombination corresponding to partial regions of the two adjacent genes recA and recX (248 bp) was identified between A. bestiarum (major parent) and Aeromonas eucrenophila (minor parent). The low number of recombinant strains detected (1.8%) suggests that horizontal flow between recA sequences is relatively uncommon in this genus. Moreover, only a few nucleotide differences were detected among these fragments, indicating that recombination has occurred recently. Finally, we also determined if the recombinant fragment could have influenced the structure and basic functions of the RecA protein, comparing models reconstructed from the translated amino acid sequences of our A. bestiarum strains with known Escherichia coli RecA structures.

  7. Aeromonas rivipollensis sp. nov., a novel species isolated from aquatic samples.

    Science.gov (United States)

    Marti, Elisabet; Balcázar, José Luis

    2015-12-01

    Two gram-negative, facultatively anaerobic, motile and rod-shaped bacteria, strains P2G1(T) and P1A11, were isolated from the Ter River in Ripoll, Spain. Phylogenetic analysis based on 16S rRNA gene sequences showed that both strains are closely related to each other and that their closest relatives were Aeromonas media ATCC 33907(T) (99.4%) and Aeromonas hydrophila ATCC 7966(T) (99.3%). Multilocus sequence analysis (MLSA) based on the partial sequences of gyrA, gyrB, rpoD, recA, and dnaJ genes suggested that these two strains represent a novel species that clustered with A. media ATCC 33907(T). This was further supported by DNA-DNA hybridization analysis between P2G1(T) and A. media LMG 9073(T). Phenotypic features also allowed their differentiation from closely related species. These two strains should, therefore, be considered to represent a novel species within the genus Aeromonas, for which the name Aeromonas rivipollensis sp. nov. is proposed.

  8. Molecular Characterization of a Functional Type VI Secretion System from a Clinical Isolate of Aeromonas hydrophilia

    Science.gov (United States)

    Our laboratory recently molecularly characterized the type II secretion system (T2SS)-associated cytotoxic enterotoxin (Act) and the T3SS-secreted AexU effector from a diarrheal isolate SSU of Aeromonas hydrophila. The role of these toxin proteins in the pathogenesis of A. hydrop...

  9. Lippia alba essential oil promotes survival of silver catfish (Rhamdia quelen) infected with Aeromonas sp.

    Science.gov (United States)

    Sutili, Fernando J; Cunha, Mauro A; Ziech, Rosangela E; Krewer, Carina C; Zeppenfeld, Carla C; Heldwein, Clarissa G; Gressler, Leticia T; Heinzmann, Berta M; Vargas, Agueda C; Baldisserotto, Bernardo

    2015-03-01

    In vitro and in vivo activity of the Lippia alba essential oil (EO) against Aeromonas sp. was evaluated. In the in vitro assay the minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of EO for Aeromonas cells were determined using the microdilution method. Twenty five strains of Aeromonas sp. isolated from infected fish obtained from local fish farms were used. MIC and MBC values were 2862 and 5998 µg mL-1 for L. alba EO and 0.5 and 1.2 µg mL-1 for gentamicin, respectively. In the in vivo assay silver catfish juveniles (Rhamdia quelen) (7.50 ± 1.85 g and 10.0 ± 1.0 cm) with typical injuries associated to Aeromonas infection were divided into four treatments (in triplicate n=10): untreated fish (negative control), 10 mg L-1 of gentamicin, and 20 or 50 µL L-1 of EO. Fish were maintained in aerated 20 L plastic boxes. After 10 days survival of silver catfish infected with Aermonas sp. and treated with essential oil (50 µL L-1) was greater than 90%.

  10. Clinical manifestations of bacteremia caused by Aeromonas species in southern Taiwan.

    Directory of Open Access Journals (Sweden)

    Hung-Jen Tang

    Full Text Available This study is conducted to investigate the clinical characteristics of patients with bacteremia caused by Aeromonas species.Patients with bacteremia caused by Aeromonas species during the period 2009 to 2013 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed.A total of 91 patients with bacteremia due to Aeromonas species were identified. In addition to 16 (17.6% primary bacteremia, the most common source of secondary infection is peritonitis (n = 27, 29.7%, followed by biliary tract infection (n = 18, 19.8%, and SSTI (n = 12, 13.2%, pneumonia (n = 9, 9.9%, catheter-related bloodstream infection (n =  5, 5.5%, and genitourinary tract infection (n = 4, 4.4%. A. hydrophila (n = 35, 38.5% was the most common pathogen, followed by A. veronii biovar sobria (n = 31, 34.1%, A. caviae (n = 14, 15.4%, and A. veronii biovar veronii (n = 9, 9.9%. Forty-three (47.3% patients were classified as healthcare-associated infections (HCAI causes by Aeromonas species, and patients with HCAI were more likely to have cancer, and receive immunosuppressant than patients with community-acquired bacteremia. The overall outcomes, including rate of ICU admission, acute respiratory failure, and mortality were 33.3%, 28.6%, and 23.1%, respectively. Multivariate analysis showed that the in-hospital day mortality was significantly associated only with underlying cancer (P <.001, and initial shock (P <.001.Aeromonas species should be considered one of the causative pathogens of healthcare-associated bacteremia, especially in immunocompromised patients. In addition, it can be associated with high fatality. Cancer and initial shock were the poor prognostic factors.

  11. The Animal Model Determines the Results of Aeromonas Virulence Factors

    Science.gov (United States)

    Romero, Alejandro; Saraceni, Paolo R.; Merino, Susana; Figueras, Antonio; Tomás, Juan M.; Novoa, Beatriz

    2016-01-01

    The selection of an experimental animal model is of great importance in the study of bacterial virulence factors. Here, a bath infection of zebrafish larvae is proposed as an alternative model to study the virulence factors of Aeromonas hydrophila. Intraperitoneal infections in mice and trout were compared with bath infections in zebrafish larvae using specific mutants. The great advantage of this model is that bath immersion mimics the natural route of infection, and injury to the tail also provides a natural portal of entry for the bacteria. The implication of T3SS in the virulence of A. hydrophila was analyzed using the AH-1::aopB mutant. This mutant was less virulent than the wild-type strain when inoculated into zebrafish larvae, as described in other vertebrates. However, the zebrafish model exhibited slight differences in mortality kinetics only observed using invertebrate models. Infections using the mutant AH-1ΔvapA lacking the gene coding for the surface S-layer suggested that this protein was not totally necessary to the bacteria once it was inside the host, but it contributed to the inflammatory response. Only when healthy zebrafish larvae were infected did the mutant produce less mortality than the wild-type. Variations between models were evidenced using the AH-1ΔrmlB, which lacks the O-antigen lipopolysaccharide (LPS), and the AH-1ΔwahD, which lacks the O-antigen LPS and part of the LPS outer-core. Both mutants showed decreased mortality in all of the animal models, but the differences between them were only observed in injured zebrafish larvae, suggesting that residues from the LPS outer core must be important for virulence. The greatest differences were observed using the AH-1ΔFlaB-J (lacking polar flagella and unable to swim) and the AH-1::motX (non-motile but producing flagella). They were as pathogenic as the wild-type strain when injected into mice and trout, but no mortalities were registered in zebrafish larvae. This study demonstrates

  12. Envolvimento de Aeromonas em surto de doença diarréica aguda em São Bento do Una, Pernambuco Aeromonas associated with an acute diarrhea outbreak in São Bento do Una, Pernambuco

    Directory of Open Access Journals (Sweden)

    Ernesto Hofer

    2006-04-01

    Full Text Available No primeiro semestre de 2004, ocorreu um surto de diarréia em São Bento do Una, Pernambuco, registrando-se 2.170 casos. Nas 582 coproculturas realizadas, 145 (25% revelaram um enteropatógeno bacteriano, destacando 114 casos (19,5% com a participação de Aeromonas, representadas por Aeromonas caviae (57/9,8%, Aeromonas veronii biovar sobria (23/3,9%, Aeromonas veronii biovar veronii (15/2,6% e outras espécies (19/3,2%. Nos 31 episódios restantes (5,3%, foram detectados: V. cholerae O1 Ogawa toxigênico (18/3,1%, Salmonella spp (8/1,4%, Shigella spp (3/0,5% e Vibrio cholerae não O1/não O139 (2/0,3%.An acute diarrhea outbreak, with 2170 cases, was described during January to July, 2004, in São Bento do Una, Pernambuco. 582 stools were examined and an enteric pathogen was recovered in 25% (145 patients. Aeromonas species were the most frequent (114-19.5% and the main isolates were Aeromonas caviae (57-9.8%, Aeromonas veronii biovar sobria (23-3.9%, Aeromonas veronii biovar veronii (15-2.6% and other species (19-3.2%. The other isolated enteropathogens were Vibrio cholerae O1-Ogawa toxigenic (18-3.1%, Salmonella spp (8-1.4%, Shigella spp (3-0.5% and Vibrio cholerae non-O1/non-O139 (2-0.3%.

  13. Survival and recovery of Aeromonas hydrophila in water: development of methodology for testing bottled water in Canada.

    Science.gov (United States)

    Warburton, D W; McCormick, J K; Bowen, B

    1994-02-01

    Proposed changes to the Regulations for bottled water in the Food and Drugs Act of Canada include criteria for Aeromonas hydrophila (0 colony-forming units/100 mL water). The development of the methodology used to support these proposed Regulations and the survival of A. hydrophila in inoculated water are described. The methodology used in the isolation of A. hydrophila includes the use of hydrophobic grid membrane filters (HGMF), a resuscitation step on tryptic soy agar, and selective plating on membrane-Aeromonas-trehalose agar and Aeromonas medium. Aeromonas hydrophila proliferated and survived in inoculated water for up to 60 days or longer depending on the other contaminating bacteria. The presence of Pseudomonas aeruginosa enhanced the survival of A. hydrophila and enabled this bacteria to survive for more than 60 days.

  14. Reciprocal immune benefit based on complementary production of antibiotics by the leech Hirudo verbana and its gut symbiont Aeromonas veronii

    OpenAIRE

    Aurélie Tasiemski; François Massol; Virginie Cuvillier-Hot; Céline Boidin-Wichlacz; Emmanuel Roger; Franck Rodet; Isabelle Fournier; Frédéric Thomas; Michel Salzet

    2015-01-01

    International audience; The medicinal leech has established a long-term mutualistic association with Aeromonas veronii, a versatile bacterium which can also display free-living waterborne and fish-or human-pathogenic lifestyles. Here, we investigated the role of antibiotics in the dynamics of interaction between the leech and its gut symbiont Aeromonas. By combining biochemical and molecular approaches, we isolated and identified for the first time the antimicrobial peptides (AMPs) produced b...

  15. Determination of the Viability of Aeromonas hydrophila in Different Types of Water by Flow Cytometry, and Comparison with Classical Methods

    OpenAIRE

    Pianetti, Anna; Falcioni, Tania; Bruscolini, Francesca; Sabatini, Luigia; Sisti, Elivio; Papa, Stefano

    2005-01-01

    The presence of Aeromonas spp. in water can represent a risk for human health. Therefore, it is important to know the physiological status of these bacteria and their survival in the environment. We studied the behavior of a strain of Aeromonas hydrophila in river water, spring water, brackish water, mineral water, and chlorinated drinking water, which had different physical and chemical characteristics. The bacterial content was evaluated by spectrophotometric and plate count techniques. Flo...

  16. A rapid MALDI-TOF MS identification database at genospecies level for clinical and environmental Aeromonas strains.

    Directory of Open Access Journals (Sweden)

    Cinzia Benagli

    Full Text Available The genus Aeromonas has undergone a number of taxonomic and nomenclature revisions over the past 20 years, and new (subspecies and biogroups are continuously described. Standard identification methods such as biochemical characterization have deficiencies and do not allow clarification of the taxonomic position. This report describes the development of a matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS identification database for a rapid identification of clinical and environmental Aeromonas isolates.

  17. Phenotypical characteristics, genetic identification, and antimicrobial sensitivity of Aeromonas species isolated from farmed rainbow trout (Onchorynchus mykiss) in Mexico.

    Science.gov (United States)

    Vega-Sánchez, Vicente; Acosta-Dibarrat, Jorge; Vega-Castillo, Fernando; Castro-Escarpulli, Graciela; Aguilera-Arreola, Ma Guadalupe; Soriano-Vargas, Edgardo

    2014-02-01

    In the present study, Aeromonas isolates from diseased and healthy farmed rainbow trout (Oncorhynchus mykiss) in Mexico, were characterized phenotypically and identified to species level by using 16S rDNA RFLP-PCR. A total of 50 isolates were included in the study and 10 Aeromonas species identified. The species A. veronii biovar sobria (22%), A. hydrophila (20%) and A. bestiarum (20%) were the most predominant. All isolates (100%) were resistant to cephalothin.

  18. Incidence of Aeromonas spp. infection in fish and chicken meat and its related public health hazards: A review

    Directory of Open Access Journals (Sweden)

    Praveen Kumar Praveen

    2016-01-01

    Full Text Available Aeromonas is recognized to cause a variety of diseases in man. In humans, they are associated with intestinal and extraintestinal infections. With the growing importance of Aeromonas as an emerging pathogen, it is important to combat this organism. It is indisputable that Aeromonas strains may produce many different putative virulence factors such as enterotoxins, hemolysins or cytotoxins, and antibiotic resistance against different antibiotics. The ability of these bacteria to grow competitively at 5°C may be indicative of their potential as a public health hazard. Comprehensive enteric disease surveillance strategies, prevention and education are essential for meeting the challenges in the years ahead. It is important for us to promote the value of enteric cultures when patients have a gastrointestinal illness or bloody diarrhea or when multiple cases of enteric disease occur after a common exposure. With the growing importance of Aeromonas as an emerging pathogen, it is important to combat this organism. It is indisputable that Aeromonas strains may produce many different putative virulence factors, such as enterotoxins, hemolysins or cytotoxins. It has been established that aerolysin is a virulence factor contributing to the pathogenesis of Aeromonas hydrophila infection. Fish and chicken play an important role in the transmission of this pathogen to humans. In the present study, the high prevalence of toxin-producing strains was found among the Aeromonas isolates. The ability of these bacteria to grow competitively at 5°C may be indicative of their potential as a public health hazard. The present review was constructed with a view to highlight the zoonotic importance of Aeromonas pathogen in fish and chicken meat.

  19. AEROMONAS SPP BACTEREMIA OF RAINBOW TROUT FRY (ONCORHYNCHUS MYKISS: BIOCHEMICAL CHARACTERIZATION OF THE CAUSATIVE ORGANISM AND ANTIMICROBIAL SUSCEPTIBILITY

    Directory of Open Access Journals (Sweden)

    Damir Kapetanović

    2004-09-01

    Full Text Available Aeromonas hydrophila and other members of Aeromonas genus are ubiquitus in aquatic environment and make part of normal bacterial flora of rainbow trout. Aeromonas spp. infections are worldwide registered. Here we present our experience and knowledge on Aeromonas bacteremia, which causes mortality of rainbow trout fry. Rainbow trout fry, 7 month old, started to die in November 2003. Fish samples (17 samples of dead and moribund fish were delivered to the Laboratory for aquaculture. With Api 20 NE tests Aeromonas hydrophila / caviae type I was identified with an average probability of 99.9 % (one test against, as well as Aeromonas hydrophila / caviae type II with an average probability of 99.5 % (one test against from liver, spleen, kidney, intestines and damaged eye. All of isolated and identified samples were tested for antibiotic susceptibility by disc diffusion method. The test showed that specimens were most sensitive on flumequin, and relatively less sensitive on chloramphenicol and enrofloxacin. Therapy was successfully applied with Flubactin®.

  20. Reciprocal immune benefit based on complementary production of antibiotics by the leech Hirudo verbana and its gut symbiont Aeromonas veronii.

    Science.gov (United States)

    Tasiemski, Aurélie; Massol, François; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Roger, Emmanuel; Rodet, Franck; Fournier, Isabelle; Thomas, Frédéric; Salzet, Michel

    2015-12-04

    The medicinal leech has established a long-term mutualistic association with Aeromonas veronii, a versatile bacterium which can also display free-living waterborne and fish- or human-pathogenic lifestyles. Here, we investigated the role of antibiotics in the dynamics of interaction between the leech and its gut symbiont Aeromonas. By combining biochemical and molecular approaches, we isolated and identified for the first time the antimicrobial peptides (AMPs) produced by the leech digestive tract and by its symbiont Aeromonas. Immunohistochemistry data and PCR analyses evidenced that leech AMP genes are induced in the gut epithelial cells when Aeromonas load is low (starved animals), while repressed when Aeromonas abundance is the highest (post blood feeding). The asynchronous production of AMPs by both partners suggests that these antibiotic substances (i) provide them with reciprocal protection against invasive bacteria and (ii) contribute to the unusual simplicity of the gut microflora of the leech. This immune benefit substantially reinforces the evidence of an evolutionarily stable association between H. verbana and A. veronii. Altogether these data may provide insights into the processes making the association with an Aeromonas species in the digestive tract either deleterious or beneficial.

  1. 我国嗜水气单胞菌感染研究概况%Research Survey on Infection of Aeromonas hydrophila in China

    Institute of Scientific and Technical Information of China (English)

    陈翠珍

    2012-01-01

    主要从嗜水气单胞菌感染的发现、人的嗜水气单胞菌感染、动物的嗜水气单胞菌感染、诊断要点及防控等方面对我国嗜水气单胞菌感染进行了综述。%In this report, infection of Aeromonas hydrophila overview in China was reviewed from several as- pects including the occurrence of Aeromonas hydrophila infection ,Aeromonas hydrophila infection in human be- ing and animal, diagnosis, as well as the control strategies of Aeromonas hydrophila infection.

  2. Proinflammatory cytokine and cytokine receptor gene expression kinetics following challenge with Flavobacterium psychrophilum in resistant and susceptible lines of rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Kutyrev, Ivan; Cleveland, Beth; Leeds, Timothy; Wiens, Gregory D

    2016-11-01

    Flavobacterium psychrophilum (Fp) is the causative agent of bacterial cold water disease (BCWD) which causes appreciable economic losses in rainbow trout aquaculture. We previously reported development of a genetic line, designated ARS-Fp-R that exhibits higher survival relative to a susceptible line, designated ARS-Fp-S, following either laboratory or natural on-farm challenge. The objectives of this study were to determine the temporal kinetics of gene expression between experimentally-challenged ARS-Fp-R and ARS-Fp-S fish and the correlation between gene expression and pathogen load. We developed a GeXP multiplex RT-PCR assay to simultaneously examine expression of immune-relevant genes, concentrating on tumor necrosis factor and interleukin-1 ligand/receptor systems and acute phase response genes. Spleen tissue was sampled at 6 h, 24 h, 48 h and 144 h post-challenge and pathogen load quantified by qPCR. Transcript abundance of cytokine genes tnfa1, tnfa2, tnfa3, il1b1, il1b2, il11a; acute phase response genes saa and drtp1; and putative cytokine receptors il1r1-like-b, il1r2, tnfrsf1a, tnfrsf9, tnfrsf1a-like-b increased following challenge while the transcript abundance of il1r-like-1 and tnfrsf1a-like-a decreased compared to PBS-injected line-matched control fish. Principal component analysis identified transcript levels of genes il1r-like-1 and tnfrsf1a-like-a as exhibiting differential expression between genetic lines. In summary, Fp i.p. injection challenge elicited a proinflammatory cytokine gene expression response in the spleen, with ARS-Fp-R line fish exhibiting modestly higher basal expression levels of several putative cytokine receptors. This study furthers the understanding of the immune response following Fp challenge and differences in gene expression associated with selective breeding for disease resistance.

  3. Pathogenicity of Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis to brown tree frogs (Litoria ewingii).

    Science.gov (United States)

    Schadich, Ermin; Cole, Anthony L J

    2010-04-01

    Bacterial dermatosepticemia, a systemic infectious bacterial disease of frogs, can be caused by several opportunistic gram-negative bacterial species including Aeromonas hydrophila, Chryseobacterium indologenes, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Serratia liquifaciens. Here we determined the pathogenicity of 3 bacterial species (Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis) associated with an outbreak of fatal dermatosepticemia in New Zealand Litoria ewingii frogs. A bath challenge method was used to expose test frogs to individual bacterial species (2 x 10(7) cfu/mL in pond water); control frogs were exposed to uninfected pond water. None of the control frogs or those exposed to A. hydrophila or P. mirabilis showed any morbidity or mortality. Morbidity and mortality was 40% among frogs exposed to K. pneumonia, and the organism was reisolated from the hearts, spleens, and livers of affected animals.

  4. The Social Life of Aeromonas through Biofilm and Quorum Sensing Systems

    Science.gov (United States)

    Talagrand-Reboul, Emilie; Jumas-Bilak, Estelle; Lamy, Brigitte

    2017-01-01

    Bacteria of the genus Aeromonas display multicellular behaviors herein referred to as “social life”. Since the 1990s, interest has grown in cell-to-cell communication through quorum sensing signals and biofilm formation. As they are interconnected, these two self-organizing systems deserve to be considered together for a fresh perspective on the natural history and lifestyles of aeromonads. In this review, we focus on the multicellular behaviors of Aeromonas, i.e., its social life. First, we review and discuss the available knowledge at the molecular and cellular levels for biofilm and quorum sensing. We then discuss the complex, subtle, and nested interconnections between the two systems. Finally, we focus on the aeromonad multicellular coordinated behaviors involved in heterotrophy and virulence that represent technological opportunities and applied research challenges. PMID:28163702

  5. Lipid metabolism in tumour bearing mice treated withAeromonas L-asparaginase.

    Science.gov (United States)

    Benny, P J; Kurup, G M; Sreejith, K

    1997-07-01

    The anticancerous drug isolated in our laboratory from estuarineAeromonas was characterised and is found to be an enzyme, L-asparaginase. The antileukaemic effect of this drug was studied in mice by inducing leukaemia with Ehrlich ascites cell lines. It was compared with commercially available drug, Leunase, isolated fromE. coli. The lipid profiles in mice during leukaemia and under treatment was studied. The decreased levels of cholesterol and increased levels of triglycerides and phospholipids in serum, liver and kidney were observed in tumour bearing mice. Significant changes in the above values were observed with enzyme therapy. It could bring some of the values to near normal level. L-asparaginase fromAeromonas was found to be more effective.

  6. Experimental challenge studies in Vietnamese catfish, Pangasianodon hypophthalmus (Sauvage), exposed to Edwardsiella ictaluri and Aeromonas hydrophila.

    Science.gov (United States)

    Crumlish, M; Thanh, P C; Koesling, J; Tung, V T; Gravningen, K

    2010-09-01

    The two main diseases in the pangasius catfish industry are bacillary necrosis of Pangasianodon (BNP) and motile aeromonas septicaemia (MAS), where the aetiological agents have been identified as Edwardsiella ictaluri and Aeromonas hydrophila, respectively. In this study, apparently healthy Pangasianodon hypophthalmus were exposed to E. ictaluri, A. hydrophila or both bacterial species by intraperitoneal injection or immersion. There were 20 fish per treatment group, and the bacterial isolates used for the study were recovered from natural infections of BNP or MAS in farmed Vietnamese P. hypophthalmus. The results of the experimental infections mimicked the natural disease outbreaks reported from these pathogens in P. hypophthalmus. Furthermore, it was clearly demonstrated that E. ictaluri was only recovered from the fish exposed to the bacterium and not recovered from the animals receiving A. hydrophila.

  7. [Role of Aeromonas in the monitoring of a hydroecosystem in the Volga-Caspian area].

    Science.gov (United States)

    Obukhova, O V; Lartseva, L V; Lisitskaia, I A

    2011-01-01

    The paper gives data obtained over many years on the quantity of bacteria of the genus Aeromonas in the hydroecosystems of the delta of the Volga and Caspian Sea and in commercial fishes (sturgeon (Acipenseridae), pike perch (Stizostedion), carp (Cyprinus carpio), silurus (Silurus glanis), etc.). It provides a detailed analysis of their seasonal trends and spatial distribution, markers of their pathogenicity, and antibiotic resistance. The findings suggest that Aeromonas is a causative agent of sapronoses and meets the criteria for natural focal infections. They show a wide range of tolerance to the abiotic factors of hydroecosystems, as well as mixotrophy and autrophic nutrition in the environment and they are of great sanitary and hygienic importance.

  8. EVALUATING VIRULENCE OF WATERBORNE AND CLINCIAL AEROMONAS ISOLATES USING GENE EXPRESSION AND MORTALITY IN NEONATAL MICE FOLLOWED BY ASSESSING CELL CULTURE'S ABILITY TO PREDICT VIRULENCE BASED ON TRANSCRIPTIONAL RESPONSE

    Science.gov (United States)

    The virulence of multiple Aeromonas spp. were assessed using two models, a neonatal mouse assay and a mouse intestinal cell culture. Transcriptional responses to both infection models were assessed using microarrays. After artificial infection with a variety of Aeromonas spp., ...

  9. Necrotizing Fasciitis Caused by Inconspicuous Infection of Aeromonas hydrophila in an Immunocompromised Host

    Directory of Open Access Journals (Sweden)

    Kuo-Chun Liao

    2010-09-01

    Full Text Available We present a case of serious necrotizing fasciitis due to Aeromonas hydrophila without a suggestive history of routes of pathogen invasion in a 60-year-old male. Despite prompt broad-spectrum antibiotic and extensive surgical therapies, the patient died within 72 hours following initial presentation. Our experience suggests clinicians be highly alert to the disease when an immunocompromised patient featured fulminant soft-tissue infection in the endemic area.

  10. Influence of food system conditions on N-acyl-L-homoserine lactones production by Aeromonas spp.

    Science.gov (United States)

    Medina-Martínez, M S; Uyttendaele, M; Demolder, V; Debevere, J

    2006-12-01

    Eleven of 13 Aeromonas strains were shown to produce AHLs. Results of TLC showed that N-butanoyl-L-homoserine lactone (C4-HSL) was the main AHL produced in LB medium at 30 degrees C. The influence of different carbon sources, temperature, pH values and salt concentrations on AHL production was determined in eight A. hydrophila and one A. caviae strain. Additionally a quantitative study of C4-HSL production by A. hydrophila strain 519 under different conditions was performed. Positive results were found in the AHL induction assay for some Aeromonas strains in cultures in LB agar incubated at 12 degrees C after 72-96 h. The induction of the sensor strains by Aeromonas spp. occurred in LB medium supplemented with all carbon sources in a concentration of 0.5%. The production of C4-HSL by A. hydrophila 519 was found until 3.5% (w/v) of NaCl. For pHs close to the neutrality the C4-HSL production by A. hydrophila was evident after 24-48 h of incubation. A. hydrophila 519 produced C4-HSL under anaerobic conditions. Also, the AHL production by Aeromonas strains was studied in simulate agar of shrimp, fish and some vegetables. The production of AHLs was evident by almost all the test strains in shrimp simulated agar. In fish agar only for one of three fish species tested, positive results were found. Induction assay in vegetables simulated agar showed principally negative results, probably because of the presence of inhibitory compounds in these vegetables.

  11. Rapid biochemical screening for Salmonella, Shigella, Yersinia, and Aeromonas isolates from stool specimens.

    OpenAIRE

    De Ryck, R; Struelens, M. J.; Serruys, E

    1994-01-01

    Four screens for the rapid (4 to 6 h) biochemical detection of pathogens from enteric isolation media are described. The Salmonella screen consisted of Kligler iron agar (KIA), motility-indole-urea-tryptophan-deamination semisolid medium (MIU-TDA), and the o-nitrophenyl-beta-D-galactopyranoside (ONPG) test; the Shigella screen consisted of KIA, MIU-TDA, the ONPG test, and the lysine decarboxylation-indole test; the Yersinia screen consisted of a rhamnose broth; the Aeromonas screen consisted ...

  12. ANTIBIOTICS RESISTANCE AND PUTATIVE VIRULENCE FACTORS OF AEROMONAS HYDROPHILA ISOLATED FROM ESTUARY

    OpenAIRE

    Olumide Adedokun Odeyemi; Ahmad Asmat; Gires Usup

    2012-01-01

    This study aim to investigate antibiotics resistance profile and putative virulence factors of Aeromonas hydrophila isolated from estuary. Bacteria used for this study were isolated from water and sediment samples obtained from Sungai Melayu, Johor, Malaysia. Serially diluted 100 µL water and 1g sediment were inoculated on modified Rimler - Shott (mRS) agar. Colonies with distinct cultural characteristics were picked for further studies. Isolates were tested for biofilm productions, protease ...

  13. Resistensi Bakteri Aeromonas sp. Isolat Ikan Piranha (Pygosentrus nattereri Bali Safari And Marine Park terhadap Antibiotik

    Directory of Open Access Journals (Sweden)

    Ni Made Herawati

    2013-11-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Piranha (Pygosentrus nattereri is a fish that has been conserved at Conservation Center of Bali Safari and Marine Park. In May 2012 there was a case that twelve Piranhas suffered from illness and two of them died without any specific clinical signs. The dead Piranhas were necropsied and the tissues or parts of organs were collected for microbial examination interests. Spesies specific bacterial examination was also included using Microgen GNA TM + B-ID system test The bacterial examination found that the fishes were infected by Aeromonas hydropila and Aeromonas veronii. Further examination about antibiotic resistance tests showed that those Aeromonas spp were resistant to chloramphenicol and a combination of trimethoprim and sulphamethoxazole. It can be suggested that, next, the usage of other antibiotics is strongly recommended for the case of Piranha infected by Aeromonas spp at Bali Safari and Marine Park. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; text-align:justify; line-height:150%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

  14. Natural transformation as a mechanism of horizontal gene transfer among environmental Aeromonas species.

    Science.gov (United States)

    Huddleston, Jennifer R; Brokaw, Joshua M; Zak, John C; Jeter, Randall M

    2013-06-01

    Aeromonas species are common inhabitants of aquatic environments and relevant as human pathogens. Their potential as pathogens may be related in part to lateral transfer of genes associated with toxin production, biofilm formation, antibiotic resistance, and other virulence determinants. Natural transformation has not been characterized in aeromonads. DNA from wild-type, prototrophic strains that had been isolated from environmental sources was used as donor DNA in transformation assays with auxotrophs as the recipients. Competence was induced in 20% nutrient broth during the stationary phase of growth. Optimal transformation assay conditions for one chosen isolate were in Tris buffer with magnesium or calcium, pH 5-8, and a saturating concentration of 0.5 μg of DNA per assay (3.3 ng of DNA μl⁻¹) at 30°C. Sodium was also required and could not be replaced with ammonium, potassium, or lithium. The maximal transformation frequency observed was 1.95 × 10⁻³ transformants (recipient cell)⁻¹. A survey of environmental Aeromonas auxotrophic recipients (n=37), assayed with donor DNA from other wild-type environmental aeromonads under optimal assay conditions, demonstrated that 73% were able to act as recipients, and 100% were able to act as donors to at least some other aeromonads. Three different transformation groups were identified based on each isolates' ability to transform other strains with its DNA. The transformation groups roughly corresponded to phylogenetic groups. These results demonstrate that natural transformation is a general property of Aeromonas environmental isolates with implications for the genetic structures of coincident Aeromonas populations.

  15. PROBIOTIK Bacillus firmus UNTUK PENGENDALIAN PENYAKIT Aeromonas hydrophila PADA BUDIDAYA IKAN LELE DUMBO, Clarias gariepinus

    OpenAIRE

    Angela Mariana Lusiastuti; Tuti Sumiati; Wartono Hadie

    2013-01-01

    Penelitian ini bertujuan untuk mengetahui efektivitas pemberian bakteri probiotik Bacillus firmus terhadap ketahanan benih ikan lele dumbo (Clarias gariepinus) yang diinfeksi Aeromonas hydrophila. Probiotik diberikan melalui media budidaya dengan Rancangan Acak Lengkap (RAL) menggunakan lima perlakuan dan tiga ulangan yang diaplikasikan untuk pengendalian penyakit motile aromonas septicemia (MAS). Perlakuan tersebut adalah A (tanpa penambahan bakteri probiotik B. firmus (sebagai control), B (...

  16. Rainbow trout fed diets with varying content of marine and plant origin; how does that influence the outcome of experimental infections of the fry with Flavobacterium psychrophilum and Yersinia ruckeri?

    DEFF Research Database (Denmark)

    Madsen, Lone; Ingerslev, Hans-Christian; Boye, Mette

    2014-01-01

    Feed for rainbow trout aquaculture has traditionally been based on marine resources such as fish meal and fish oil. Because of a shortage of marine resources as well as the growing production of farmed fish, the feed industry has been forced to partially exchange fish meal protein with proteins...... derived from plants, like soy bean meal. This has been shown to affect the salmonid intestinal mucosa, and in addition, plant-based dietary proteins have been associated with changes in disease susceptibility in salmon and it has been suggested that these special diet types weakens the immune status...... of the fish. One major cause for losses in Danish freshwater fish farms is the fry disease rainbow trout fry syndrome (RTFS), caused by the bacterium Flavobacterium psychrophilum, and experiences of the fish farmers suggest that the diet type is an important factor for disease development. Enteric redmouth...

  17. Anti-biogram and resistogram profiling of Aeromonas species isolated from Malaysian aquatic sources

    Institute of Scientific and Technical Information of China (English)

    Olumide Adedokun Odeyemi; Asmat Ahmad

    2013-01-01

    Objective: To investigate antibiotics and heavy metals resistance profile of Aeromonas species isolated from Kuala Gula and Kuala Sepetang, Perak. Methods: Isolated Aeromonas species were subjected to 12 antibiotics: penicillin G 10 units, tetracycline 30 µg, novobiocin 5 µg, nitrofurantoin 100 µg, ampicillin 10 µg, chloramphenicol 10 µg, fluconazole 25 µg, gentamicin 10 µg, streptomycin 10 µg and 25 µg, kanamycin 30 µg, and vancomycin 30 µg and 5 heavy metals: MnSO4.H2O, Cr(NO3).9H2O, CuSO4, Pb(NO3)2, HgCl2. Results: Results from this study revealed that isolates from the two sources-displayed varied resistance. Isolates from Kuala Sepetang showed 91%, 66%, 61%, and 52% resistance to vancomycin, Novobiocin, streptomycin and gentamycin while Kuala Gula isolates showed 76%, 93%, 28% and 14% respectively. High rate of resistance was shown to be against lead (Pb), Chromium (Cr), copper (Cu) and Manganese (Mn) with minimum inhibitory concentration ranging from 2 560 µg/mL to>5120 µg/mL. Low resistance to mercury was observed among isolates from Kuala Gula. Conclusions: This study showed that there was widespread of both heavy metals and antibiotics resistance among Aeromonas isolates from the two marine sources with isolates from Kuala Sepetang showing more resistance thereby posing danger to both aquatic animals and human health.

  18. Anti-biogram and resistogram profiling of Aeromonas species isolated from Malaysian aquatic sources

    Directory of Open Access Journals (Sweden)

    Olumide Adedokun Odeyemi

    2013-09-01

    Full Text Available Objective: To investigate antibiotics and heavy metals resistance profile of Aeromonas species isolated from Kuala Gula and Kuala Sepetang, Perak. Methods: Isolated Aeromonas species were subjected to 12 antibiotics: penicillin G 10 units, tetracycline 30 µg, novobiocin 5 µg, nitrofurantoin 100 µg, ampicillin 10 µg, chloramphenicol 10 µg, fluconazole 25 µg, gentamicin 10 µg, streptomycin 10 µg and 25 µg, kanamycin 30 µg, and vancomycin 30 µg and 5 heavy metals: MnSO4.H2O, Cr(NO3.9H2O, CuSO4, Pb(NO32, HgCl2. Results: Results from this study revealed that isolates from the two sources-displayed varied resistance. Isolates from Kuala Sepetang showed 91%, 66%, 61%, and 52% resistance to vancomycin, Novobiocin, streptomycin and gentamycin while Kuala Gula isolates showed 76%, 93%, 28% and 14% respectively. High rate of resistance was shown to be against lead (Pb, Chromium (Cr, copper (Cu and Manganese (Mn with minimum inhibitory concentration ranging from 2 560 µg/mL to >5 120 µg/mL. Low resistance to mercury was observed among isolates from Kuala Gula. Conclusions: This study showed that there was widespread of both heavy metals and antibiotics resistance among Aeromonas isolates from the two marine sources with isolates from Kuala Sepetang showing more resistance thereby posing danger to both aquatic animals and human health.

  19. DAYA HAMBAT EKSTRAK METANOL RUMPUT LAUT (Euchema spinosum TERHADAP BAKTERI Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Y Yunus

    2009-10-01

    Full Text Available Rumput laut secara tradisional telah lama dimanfaatkan sebagai bahan makanan, kosmetik dan obat-obatan, karena kaya akan mineral, elemen makro dan elemen  mikro lainnya, disamping itu rumput laut juga berfungsi sebagai bahan antimikroba seperti penyakit bakteri Aeromonas hydrophila yang sering menginfeksi ikan pada budidaya air tawar sehingga banyak merugikan petani. Oleh karena itu, maka perlu dilakukan penelitian tentang konsentrasi ekstrak metanol rumput laut yang efektif. Tujuan dari penelitian ini adalah untuk mengetahui konsentrasi ekstrak metanol rumput laut Eucheuma spinosum yang tepat untuk menghambat pertumbuhan bakteri Aeromonas hydrophyla. Metode penelitian yang digunakan adalah metode eksperimen, Pertama menggunakan Uji MIC  konsentrasi sebagai berikut : 25%; 12,5%; 6,25%; 3,125%; 1,56%; 0,78%; 0,39%; 0,195%; 0,098%; 0,049%; 0,025%; dan 0,0125%. Kedua menggunakan Uji Cakram konsentrasi 3%, 6%, 9%, 12%, dan 0%  sebagai kontrol. Hasil uji MIC setelah dibandingkan dengan kontrol positif sangat rendah yaitu sebesar 0,049%, hasil ini menunjukkan bahwa konsentrasi tersebut menghambat pertumbuhan bakteri Aeromnas hydrophila. Pada hasil uji cakram kemampuan ekstrak rumput laut pada konsentrasi 3%, 6% dan 9% dalam menghambat bakteri Aeromons hydrophila bersifat bakteriostatik, sedangkan pada konsentrasi 12% bersifat bakteriosidal.  Kata Kunci : Eucheuma spinosum, Polifenol, Aeromonas hydrophila

  20. Synthesis and evaluation of bactericidal properties of CuO nanoparticles against Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Sayedeh Fatemeh Shaffiey

    2014-04-01

    Full Text Available   Objective(s: CuO is one of the most important transition metal oxides due to its captivating properties. It is used in various technological applications such as high critical temperature superconductors, gas sensors, in photoconductive applications, and so on. Recently, it has been used as an antimicrobial agent against various bacterial species.   Materials and Methods: Here, we synthesized CuO nanoparticles (NPs and explored the antibacterial activity of CuO NPs preparation. Results: Single crystalline nanoparticles of copper oxide having almost uniform particle size of 5-6 nm has been synthesized by a facile and versatile route. XRD spectra confirmed the formation of single phase CuO NPs. Transmission electron microscopy results corroborate well with XRD results. The technique employed is free from toxic solvents, organics and amines, is based on a simple reaction of copper sulfate and de-ionized water (DI, and their bactericidal effects against of Aeromonas hydrophila ATCC 7966T bacteria were investigated. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC with liquid culture for all of the Aeromonas hydrophila culture Medias was done. Conclusion: Present study confirms that Copper oxide nanoparticles have great promise as antimicrobial agent against Aeromonas hydrophila

  1. Toxin Production by Aeromonas sobria in Natural Environments: River Water vs. Seawater

    Directory of Open Access Journals (Sweden)

    Ramamurthy,Thandavarayan

    2008-12-01

    Full Text Available Aeromonas are water-borne pathogens. They are halotolerant, which means that they can survive in environments whose salt content corresponds to that of seawater (3.0% NaCl. However, the presence of Aeromonas in seawater is extremely rare compared with that in river water. In this study, we tested the ability of Aeromonas sobria to produce toxins in river water and seawater. First, we cultured A. sobria on skim milk agar plates supplemented with either river water (SARW or seawater (SASW. The bacteria grew on both plates. A clear zone around the bacteria was generated in SARW. However, such a zone was not observed in SASW, suggesting that proteases were not generated in SASW. Subsequently, we cultured A. sobria in a nutrient broth supplemented with either river water (NRW or with seawater (NSW, and examined the protease activity of their culture supernatants. The protease activity of the culture supernatant from NSW was extremely low compared to that from NRW. The immunoblotting analysis showed that serine protease (ASP was not produced by the culture in NSW. By contrast, aerolysin-like hemolysin was produced in all conditions examined in this study. This indicates that the salinity of water is deeply involved in the production of ASP by A. sobria.

  2. Prevalence and antimicrobial susceptibilities of Vibrio, salmonella, and Aeromonas isolates from various uncooked seafoods in Thailand.

    Science.gov (United States)

    Woodring, Joseph; Srijan, Apichai; Puripunyakom, Paksathorn; Oransathid, Wilawan; Wongstitwilairoong, Boonchai; Mason, Carl

    2012-01-01

    Uncooked seafood samples were collected from open markets and supermarkets in Bangkok, Thailand, and were examined for the presence of Vibrio, Salmonella, and Aeromonas species from January to February 2008. From 120 samples, 272 bacterial isolates were identified through biochemical testing. Of all sea bass, shrimp, oyster, and blood cockle samples (30 of each) that were processed for culture, 114 (95%) samples had at least one detectable isolate of Vibrio, Salmonella, or Aeromonas, leaving only 6 (5%) samples free of them. All oyster sample (100%) had at least one pathogen, followed by sea bass (97%), blood cockles (97%), and shrimp (90%). Overall, 111 (92%) of all samples had detectable Vibrio spp., 32 (27%) had detectable Aeromonas spp., and 25 (21%) had detectable Salmonella enterica. There was no overall difference between positive samples collected from fresh markets versus supermarkets (relative risk, 0.97; 95% CI, 0.89 to 1.05). Resistance to ampicillin among isolated pathogens was relatively high (56%), while resistance to 12 other antibiotics, including azithromycin, ciprofloxacin, and trimethoprim-sulfamethoxazole, was relatively low (0, 0, and 3%, respectively). Study results indicate that uncooked seafood in Bangkok, Thailand, commonly harbors enteric pathogens and that consumption of uncooked seafood should be avoided to reduce foodborne illnesses.

  3. A culture independent method for the detection of Aeromonas sp. from water samples

    Directory of Open Access Journals (Sweden)

    Fadua Latif-Eugenín

    2016-01-01

    Full Text Available The genus Aeromonas is present in a wide variety of water environments and is recognised as potentially pathogenic to humans and animals. Members of this genus are often confused with Vibrio when using automated, commercial identification systems that are culture-dependent. This study describes a polymerase chain reaction (PCR detection method for Aeromonas that is culture- independent and that targets the glycerophospholopid-cholesterol acyltransferase (gcat gene, which is specific for this genus. The GCAT-PCR was 100% specific in artificially inoculated water samples, with a detection limit that ranged from 2.5 to 25 cfu/mL. The success at detecting this pathogen in 86 water samples using the GCAT-PCR method was identical to the conventional culturing method when a pre-enrichment step was carried out, yielding 83.7% positive samples. On the other hand, without a pre-enrichment step, only 77.9% of the samples were positive by culturing and only 15.1% with the GCATPCR. However, 83.7% positive samples were obtained for the GCAT-PCR when the water volume for the DNA extraction was increased from 400 μL to 4 mL. The proposed molecular method is much faster (5 or 29 h than the culturing method (24 or 48 h whether performed directly or after a pre-enrichment step and it will enable the fast detection of Aeromonas in water samples helping to prevent a possible transmission to humans.

  4. Aeromonas hydrophila-associated septicemia in captive crocodiles (Crocodylus johnstoni and Crocodylus porosus).

    Science.gov (United States)

    Roh, Yoon-Seok; Park, Heejin; Cho, Hyun-Ung; Cho, Ara; Islam, Mohammad Rafiqul; Cho, Ho-Seong; Lim, Chae Woong; Kim, Bumseok

    2011-12-01

    Five 25-yr-old crocodiles (Crocodylus johnstoni and Crocodylus porosus) were diagnosed with Aeromonas hydrophila-associated septicemia accelerated by improper thermoregulation. At necropsy, pulmonary congestion and pleural effusion were the main lesions in the thorax. Necrotizing enteritis, intestinal hemorrhage, fibrinous serositis, hepatitis, and pancreatitis were observed in the abdominal cavities of all five crocodiles. Aeromonas hydrophila was identified in the pleural effusions and abdominal ascites of all necropsied crocodiles by using an API system 20NE. Aeromonas hydrophila infection and evaluation of virulence were confirmed by polymerase chain reaction targeting the 16S rRNA and extracellular hemolysin gene. The crocodiles in the present case were housed in an indoor facility at a private zoo that failed to optimize land and water portions of the enclosure, exposing the animals to impeded thermoregulation, and it is suggested that the pathogenesis was accelerated by the improper thermoregulation-induced stress. This is the first description of A. hydrophila pathogenicity associated with impeded thermoregulation in reptiles.

  5. SELEKSI KANDIDAT PROBIOTIK ANTI AEROMONAS HYDROPHILA UNTUK PENGENDALIAN PENYAKIT IKAN AIR TAWAR

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    Angela Mariana Lusiastuti

    2012-08-01

    Full Text Available Secara dasar ada tiga model kerja probiotik yaitu menekan populasi mikroba melalui kompetisi dengan memproduksi senyawa anti-mikroba atau melalui kompetisi nutrisi dan tempat pelekatan di dinding usus, mengubah keseimbangan metabolisme mikroba dengan meningkatkan atau menurunkan aktivitas enzim dan menstimulasi imunitas dengan meningkatkan antibodi dan aktivitas makrofag. Tujuan penelitian ini adalah memperoleh mikroba yang berpotensi sebagai kandidat probiotik untuk dapat diaplikasikan di dalam menekan atau menghambat bakteri patogen sebagai langkah pengendalian penyakit pada ikan air tawar. Penelitian ini terdiri atas dua tahap, tahap pertama adalah tahap seleksi yang dimulai dari koleksi dan isolasi bakteri kandidat probiotik dan tahap kedua adalah tahap pengujian bakteri kandidat probiotik secara in vitro menggunakan metode daya hambat dan menguji daya patogenisitas bakteri. Total isolat bakteri yang diperoleh adalah 72 isolat, dan hanya enam isolat terpilih sebagai kandidat probiotik anti Aeromonas hydrophila. Probiotik anti A. hydrophila adalah sebagai berikut: Chromobacterium lividum, Alcaligenes faecalis, Aeromonas caviae, Bacteriodes serpens, Bacillus firmus, Aeromonas caviae = A. hydrophila Sub sp. Anaerogenes.

  6. Occurrence of potential pathogenic Aeromonas species in tropical seafood, aquafarms and mangroves off Cochin coast in South India

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    Alphonsa Vijaya Joseph

    2013-12-01

    Full Text Available Background: The genus Aeromonas include gram-negative, motile, facultative anaerobic, rod shaped and oxidase positive bacteria comprising several species, associated with the aquatic environment. Aeromonas species have been implicated in human pathogenesis and are linked with gastroenteritis, muscle infections, septicemia, and skin diseases. In fish they are renowned as enteric pathogens causing haemorrhagic septicemia, fin rot, soft tissue rot and furunculosis resulting in major die-offs and fish kills. Aim: This study reports the occurrence of potential pathogenic Aeromonas sp. in tropical seafood (Squids, Prawns and Mussels, aquafarms and mangroves of Cochin, Kerala, South India. Materials and Methods :Tropical seafood (Squid, Prawn and Mussel, sediment and water samples from aquafarms and associated mangroves were screened for Aeromonas contamination. The isolates were identified by 16S rDNA sequence analysis and subjected to morphological and biochemical characterization. Haemolytic assay was used for determining pathogenicity of the organisms. Antibiotic susceptibility against 12 antibiotics were performed and the MAR index was calculated. Results: A total of 134 isolates were recovered from the samples of which 15 were identified as Aeromonas species by 16S rDNA sequence analysis and were assigned to 5 species namely, A. hydrophila, A. enteropelogenes, A. caviae, A. punctataand A. aquarorium. Morphological, biochemical and phylogenetic analyses revealed relatedness and variability among the strains. All the isolates were haemolytic on blood agar indicating their pathogenicity. The isolates exhibited varying degrees of resistance to vancomycin (86.66%, ampicillin (46.66%, nalidixic acid (20%, tetracycline (6.66%, co-trimaxozole (6.66% and rifampicin (6.66% and were susceptible to antibiotics like gentamycin, streptomycin, trimethoprim, azithromycin, cefixime and chloramphenicol. 20% of Aeromonas sp. showed MAR index > 0.2 indicative of the

  7. Multidrug-resistant (MDR) Aeromonas recovered from the metropolitan area of Valencia (Spain): diseases spectrum and prevalence in the environment.

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    Esteve, C; Alcaide, E; Giménez, M J

    2015-01-01

    Aeromonas infections are rare in Europe and often related to traveller's diarrhoea. A total of 185 Aeromonas isolates from river water, fish and clinical sources, recovered during a 1-year period, were used to investigate the disease spectrum and impact of multidrug-resistant (MDR) strains. They were all identified by biochemical tests and 25% of them were also identified by sequencing of the 16S rRNA gene. The minimum inhibitory concentrations (MICs) of 21 antimicrobials were determined for all isolates by broth microdilution/E-strips methods, and susceptibility was assessed according to the Clinical and Laboratory Standards Institute (CLSI). Strains pathogenicity was determined by using Swiss Webster mice as the animal model. Aeromonas diseases had an incidence of around 20 cases/million inhabitants in the metropolitan area of Valencia (Spain). Acute gastroenteritis in children with no history of travel abroad was the main pathology. These cases were related to A. caviae, A. veronii biovar sobria, A. hydrophila and A. dhakensis. A significant incidence of A. caviae in humans was found, while the other species were equally present in clinical and environmental origins. A. jandaei, A. bestiarum and A. media had mainly an environmental distribution. The prevalence of MDR Aeromonas was maximal in clinical samples, and resistance phenotypes were significantly related to this source. 7.2% of environmental Aeromonas was resistant to at least five drugs; most of them were moderately virulent for mice and, in addition, belonged to clinically significant species. The present study demonstrates a diseases spectrum similar to that reported in tropical countries, and also that pathogenic and heavily MDR Aeromonas are present in environmental reservoirs. MDR Aeromonas from any source analysed were susceptible to aztreonam, netilmicin, cefotaxime, ceftazidime, cefepime and fluoroquinolones.

  8. Prevalence, virulence and antimicrobial resistance patterns of Aeromonas spp. isolated from children with diarrhea

    Science.gov (United States)

    Soltan Dallal, Mohammad Mehdi; Mazaheri Nezhad Fard, Ramin; Kavan Talkhabi, Morteza; Aghaiyan, Leyla; Salehipour, Zohre

    2016-01-01

    Background Aeromonas spp. cause various intestinal and extraintestinal diseases. These bacteria are usually isolated from fecal samples, especially in children under five years old. The aim of this study was to assess the prevalence of Aeromonas spp. and their antimicrobial resistance profile in children with diarrhea referred to the Children Medical Center in Tehran, between 2013 and 2014. Methods A total number of 391 stool samples were collected from children with ages between 1 day and 14 years old, with diarrhea (acute or chronic), referred to the Children Hospital, Tehran, Iran, between 2013 and 2014. Samples were enriched in alkaline peptone water broth for 24 hours at 37 °C and then cultured. Suspicious colonies were analyzed through biochemical tests. Furthermore, antimicrobial susceptibility tests were carried out for the isolates. Isolates were further studied for act, ast, alt, aerA and hlyA virulence genes using polymerase chain reaction. Results In total, 12 isolates (3.1%) were identified as Aeromonas spp.; all were confirmed using the API-20E test. Of these isolates, five A. caviae (42%), four A. veronii (33%) and three A. hydrophila (25%) were identified in cases with gastroenteritis. Second to ampicillin (which was included in the growth medium used), the highest rate of antimicrobial resistance was seen against nalidixic acid and trimethoprim-sulfamethoxazole (5 isolates each, 41.6%) and the lowest rate of antimicrobial resistance was seen against gentamicin, amikacin and cefepime (none of the isolates). Results included 76.4% act, 64.7% ast, 71.5% alt, 83.3% aerA and 11.7% hlyA genes. Conclusion Aeromonas spp. are important due to their role in diarrhea in children; therefore, isolation and identification of these fecal pathogens should seriously be considered in medical laboratories. Since virulence genes play a significant role in gastroenteritis symptoms caused by these bacteria, Aeromonas species that include virulence genes are potentially

  9. Mutation in the S-ribosylhomocysteinase (luxS) gene involved in quorum sensing affects biofilm formation and virulence in a clinical isolate of Aeromonas hydrophila

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    A diarrheal isolate SSU of Aeromonas hydrophila produces a cytotoxic enterotoxin (Act) with cytotoxic, enterotoxic, and hemolytic activities. Our laboratory has characterized from the above Aeromonas strain, in addition to Act, the type 3- and T6-secretion systems and their effec...

  10. Predicting Virulence of Aeromonas Isolates Based-on Changes in Transcription of c-jun and c-fos in Human Tissue Culture Cells

    Science.gov (United States)

    Aims: To assess virulence of Aeromonas isolates based on the change in regulation of c-jun and c-fos in the human intestinal tissue culture cell line Caco-2. Methods and Results: Aeromonas cells were added to Caco-2 cells at approximately a one to one ratio. After 1, 2 and 3 ...

  11. Complete genome sequence of the highly virulent Aeromonas hydrophila AL09-71 isolated from disease channel catfish from West Alabama

    Science.gov (United States)

    The highly virulent Aeromonas hydrophila isolate AL09-71 was cultured from infected channel catfish during the 2009 disease outbreak in West Alabama. The complete genome of this highly virulent Aeromonas hydrophila isolate AL09-71 is 5,023,861 bp in size. The genome has 4489 coding sequences, 11 cop...

  12. Two novel temperate bacteriophages co-existing in Aeromonas sp. ARM81 - characterization of their genomes, proteomes and DNA methyltransferases.

    Science.gov (United States)

    Dziewit, Lukasz; Radlinska, Monika

    2016-08-01

    Aeromonas species are causative agents of a wide spectrum of diseases in animals and humans. Although these bacteria are commonly found in various environments, little is known about their phages. Thus far, only one temperate Aeromonas phage has been characterized. Whole-genome sequencing of an Aeromonas sp. strain ARM81 revealed the presence of two prophage clusters. One of them is integrated into the chromosome and the other was maintained as an extrachromosomal, linear plasmid-like prophage encoding a protelomerase. Both prophages were artificially and spontaneously inducible. We separately isolated both phages and compared their genomes with other known viruses. The novel phages show no similarity to the previously characterized Aeromonas phages and might represent new evolutionary lineages of viruses infecting Aeromonadaceae. Apart from the comparative genomic analyses of these phages, complemented with their structural and molecular characterization, a functional analysis of four DNA methyltransferases encoded by these viruses was conducted. One of the investigated N6-adenine-modifying enzymes shares sequence specificity with a Dam-like methyltransferase of its bacterial host, while another one is non-specific, as it catalyzes adenine methylation in various sequence contexts. The presented results shed new light on the diversity of Aeromonas temperate phages.

  13. Aeromonas surface glucan attached through the O-antigen ligase represents a new way to obtain UDP-glucose.

    Science.gov (United States)

    Merino, Susana; Bouamama, Lamiaa; Knirel, Yuriy A; Senchenkova, Sofya N; Regué, Miguel; Tomás, Juan M

    2012-01-01

    We previously reported that A. hydrophila GalU mutants were still able to produce UDP-glucose introduced as a glucose residue in their lipopolysaccharide core. In this study, we found the unique origin of this UDP-glucose from a branched α-glucan surface polysaccharide. This glucan, surface attached through the O-antigen ligase (WaaL), is common to the mesophilic Aeromonas strains tested. The Aeromonas glucan is produced by the action of the glycogen synthase (GlgA) and the UDP-Glc pyrophosphorylase (GlgC), the latter wrongly indicated as an ADP-Glc pyrophosphorylase in the Aeromonas genomes available. The Aeromonas glycogen synthase is able to react with UDP or ADP-glucose, which is not the case of E. coli glycogen synthase only reacting with ADP-glucose. The Aeromonas surface glucan has a role enhancing biofilm formation. Finally, for the first time to our knowledge, a clear preference on behalf of bacterial survival and pathogenesis is observed when choosing to produce one or other surface saccharide molecules to produce (lipopolysaccharide core or glucan).

  14. Aeromonas surface glucan attached through the O-antigen ligase represents a new way to obtain UDP-glucose.

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    Susana Merino

    Full Text Available We previously reported that A. hydrophila GalU mutants were still able to produce UDP-glucose introduced as a glucose residue in their lipopolysaccharide core. In this study, we found the unique origin of this UDP-glucose from a branched α-glucan surface polysaccharide. This glucan, surface attached through the O-antigen ligase (WaaL, is common to the mesophilic Aeromonas strains tested. The Aeromonas glucan is produced by the action of the glycogen synthase (GlgA and the UDP-Glc pyrophosphorylase (GlgC, the latter wrongly indicated as an ADP-Glc pyrophosphorylase in the Aeromonas genomes available. The Aeromonas glycogen synthase is able to react with UDP or ADP-glucose, which is not the case of E. coli glycogen synthase only reacting with ADP-glucose. The Aeromonas surface glucan has a role enhancing biofilm formation. Finally, for the first time to our knowledge, a clear preference on behalf of bacterial survival and pathogenesis is observed when choosing to produce one or other surface saccharide molecules to produce (lipopolysaccharide core or glucan.

  15. Novo meio seletivo-indicador para detecção de Aeromonas e Plesiomonas: ágar UNISC New selective indicator medium for detection of Aeromonas and Plesiomonas: UNISC agar

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    Marion Pereira da Rocha

    2008-08-01

    Full Text Available Avaliou-se um novo meio seletivo-indicador (ágar UNISC para o isolamento de enteropatógenos clássicos e Aeromonas e Plesiomonas shigelloides. A capacidade de fermentação da xilose é indicada pela coloração amarela (fermentadores ou azul (não fermentadores que, aliada à prova da oxidase, constitui-se em indicador para a detecção de Aeromonas spp e Plesiomonas shigelloides. A produtividade e seletividade, avaliadas pelos índice de contagem absoluta e índice de contagem relativa indicam-no como uma alternativa aos coprocultivos clássicos porque permite, num só meio, o isolamento de Escherichia coli, Shigella spp, Salmonella spp, bem como, Aeromonas spp e Plesiomonas shigelloides, favorecendo o diagnóstico laboratorial das gastroenterites.We evaluated a new selective indicator medium (UNISC Agar for isolation of classical enteropathogens, Aeromonas spp and Plesiomonas shigelloides. The xylose fermentation capacity is indicated by a yellow color (fermenting agents or blue (no fermenting agent. This, together with the oxidase test, establishes it as an indicator for detecting Aeromonas and Plesiomonas shigelloides. Its productivity and selectivity, as assessed using the absolute count index and relative count index, indicate it as an alternative to the classical feces culturing media. This is because, in a single medium, it enables isolation of Escherichia coli, Shigella spp and Salmonella spp, in addition to Aeromonas and Plesiomonas shigelloides, thereby favoring the laboratory diagnosis of gastroenteritis.

  16. Aeromonas spp. isolated from oysters (Crassostrea rhizophorea from a natural oyster bed, Ceará, Brazil Aeromonas spp. isoladas de ostras (Crassostrea rhizophorea coletadas em um criadouro natural, Ceará, Brazil

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    Norma S. Evangelista-Barreto

    2006-06-01

    Full Text Available Between April and October 2002, thirty fortnightly collections of oysters (Crassostrea rhizophorea from a natural oyster bed at the Cocó River estuary in the Sabiaguaba region (Fortaleza, Ceará, Brazil were carried out, aiming to isolate Aeromonas spp. strains. Oyster samples were submitted to the direct plating (DP and the presence/absence (P/A methods. Aeromonas were identified in 15 (50% samples analyzed by the DP method and in 13 (43% analyzed by the P/A method. A. caviae, A. eucrenophila, A. media, A. sobria, A. trota, A. veronii bv. sobria, A. veronii bv. veronii and Aeromonas sp. were isolated. The predominant species was A. veronii (both biovars, which was identified in 13 (43% samples, followed by A. media in 11 (37% and A. caviae in seven (23%. From the 59 strains identified, 28 (48% presented resistance to at least one of the eight antibiotics tested.Foram realizadas 30 coletas quinzenais, entre abril e outubro de 2002, de ostras (Crassostrea rhizophorea de um criadouro natural, no estuário do rio Cocó (Fortaleza/Ceará/Brasil, objetivando-se isolar cepas de Aeromonas spp. As amostras de ostras foram submetidas aos métodos de plaqueamento direto (PD e presença/ausência (P/A. Foram identificadas Aeromonas em 15 (50% amostras analisadas pelo método PD e em 13 (43% pelo método P/A. Foram isoladas: A. caviae, A. eucrenophila, A. media, A. sobria, A. trota, A. veronii bv. sobria, A. veronii bv. veronii e Aeromonas sp. A espécie predominate foi A. veronii (ambos biovars, identificada em 13 (43% amostras, seguida de A. media em 11 (37% e A. caviae em 7 (23%. Das 59 cepas identificadas, 28 (48% apresentaram resistência a pelo menos um, dos oitos antibióticos testados.

  17. Necrotizing soft-tissue infections and sepsis caused by Vibrio vulnificus compared with those caused by Aeromonas species.

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    Tsai, Yao-Hung; Hsu, Robert Wen-Wei; Huang, Tsung-Jen; Hsu, Wei-Hsiu; Huang, Kuo-Chin; Li, Yen-Yao; Peng, Kuo-Ti

    2007-03-01

    Vibrio and Aeromonas species, which can cause necrotizing fasciitis and primary septicemia, are members of the Vibrionaceae family and thrive in aquatic environments. Because the clinical symptoms and signs of necrotizing fasciitis and sepsis caused by these two bacteria are similar, the purposes of this study were to describe the clinical characteristics of Vibrio vulnificus and Aeromonas infections, to analyze the risk factors for death, and to compare the effects of surgical treatment on the outcome. The cases of thirty-two patients with necrotizing soft-tissue infections and sepsis caused by Vibrio vulnificus (seventeen patients) and Aeromonas species (fifteen patients) were retrospectively reviewed over a four-year period. Surgical débridement or immediate limb amputation was initially performed in all patients. Demographic data, underlying diseases, laboratory results, and clinical outcome were analyzed for each patient in both groups. Six patients in the Vibrio vulnificus group and four patients in the Aeromonas group died. The patients who died had significantly lower serum albumin levels than did the patients who survived (p pressure at presentation (p = 0.006). The patients with Aeromonas infections who died had significantly lower white blood-cell counts (p = 0.03) with significantly fewer numbers of segmented white blood cells than those who died in the Vibrio vulnificus group (p = 0.01). The contact history of patients with a rapid onset of cellulitis can alert clinicians to a differential diagnosis of soft-tissue infection with Vibrio vulnificus (contact with seawater or raw seafood) or Aeromonas species (contact with fresh or brackish water, soil, or wood). Early fasciotomy and culture-directed antimicrobial therapy should be aggressively performed in those patients with hypotensive shock, leukopenia, severe hypoalbuminemia, and underlying chronic illness, especially a combination of hepatic dysfunction and diabetes mellitus.

  18. Quinolone resistant Aeromonas spp. as carriers and potential tracers of acquired antibiotic resistance in hospital and municipal wastewater.

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    Varela, Ana Rita; Nunes, Olga C; Manaia, Célia M

    2016-01-15

    Members of the genus Aeromonas are recognized carriers of antibiotic resistance in aquatic environments. However, their importance on the spread of resistance from hospital effluents to the environment is poorly understood. Quinolone resistant Aeromonas spp. (n = 112) isolated from hospital effluent (HE) and from raw (RWW) and treated wastewater (TWW) of the receiving urban wastewater treatment plant (UWTP) were characterized. Species identification and genetic intraspecies diversity were assessed based on the 16S rRNA, cpn60 and gyrB genes sequence analysis. The antibiotic resistance phenotypes and genotypes (qnrA, qnrB, qnrC, qnrD, qnrS, qnrVC; qepA; oqxAB; aac(6′)-Ib-cr; blaOXA; incU) were analyzed in function of the origin and taxonomic group. Most isolates belonged to the species Aeromonas caviae and Aeromonas hydrophila (50% and 41%, respectively). The quinolone and the beta-lactamase resistance genes aac(6′)-Ib-cr and blaOXA, including gene blaOXA-101, identified for the first time in Aeromonas spp., were detected in 58% and 56% of the isolates, respectively, with identical prevalence in HE and UWTP wastewater. In contrast, the gene qnrS2 was observed mainly in isolates from the UWTP (51%) and rarely in HE isolates (3%), suggesting that its origin is not the clinical setting. Bacterial groups and genes that allow the identification of major routes of antibiotic resistance dissemination are valuable tools to control this problem. In this study, it was concluded that members of the genus Aeromonas harboring the genes aac(6′)-Ib-cr and blaOXA are relevant tracers of antibiotic resistance dissemination in wastewater habitats, while those yielding the gene qnrS2 allow the traceability from non-clinical sources.

  19. Impact of thermal loading and other water quality parameters on the epizootiology of Aeromonas hydrophila infections of centrarchids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Esch, G.W.; Hazen, T.C.

    1983-01-01

    Red-sore disease is a rather recent problem for those involved in the sport and commercial fishing industries in the southeastern United States. The causative, or etiological, agent for red-sore disease is the widespread and commonly occurring bacterium, Aeromonas hydrophila. The disease is characterized by both external and internal lesions with serious damage to internal organs ultimately causing death of the host. Evidence points to the existence of several strains of Aeromonas hydrophila with some more virulent than others. The prevalence of the disease is related to elevated water temperature and body condition.

  20. ESTUDIO DE LA PATOGENICIDAD DE DIFERENTES ESPECIES DE Aeromonas EN LA TRUCHA ARCOÍRIS (Oncorhynchus mykiss)

    OpenAIRE

    ZEPEDA VELÁZQUEZ, ANDREA PALOMA

    2015-01-01

    El género Aeromonas incluye bacterias que habitan naturalmente el medio acuático, capaces de infectar diferentes especies animales, incluido el humano. Las enfermedades causadas por este género ocasionan pérdidas económicas significativas para la industria trutícola. Con el objeto de conocer la patogenicidad y virulencia de diferentes especies de Aeromonas spp., en la trucha arcoíris (Oncorhynchus mykiss), en el presente estudio se caracterizaron las lesiones macroscópicas e histológicas pres...

  1. Antibiotic and heavy metal resistance of Aeromonas hydrophila and Edwardsiella tarda isolated from red hybrid tilapia (Oreochromis spp. coinfected with motile aeromonas septicemia and edwardsiellosis

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    S. W. Lee

    2017-07-01

    Full Text Available Aim: The aim of this study is to identify antibiogram and heavy metal resistance pattern of Aeromonas hydrophila and Edwardsiella tarda isolated from red hybrid tilapia (Oreochromis spp. coinfected with motile aeromonas septicemia and edwardsiellosis in four commercial fish farms. Materials and Methods: A. hydrophila and E. tarda were isolated using glutamate starch phenol red and xylose lysine deoxycholate (Merck, Germany as a selective medium, respectively. All the suspected bacterial colonies were identified using conventional biochemical tests and commercial identification kit (BBL Crystal, USA. Susceptibility testing of present bacterial isolates to 16 types of antibiotics (nalidixic acid, oxolinic acid, compound sulfonamides, doxycycline, tetracycline, novobiocin, chloramphenicol, kanamycin, sulfamethoxazole, flumequine, erythromycin, ampicillin, spiramycin, oxytetracycline, amoxicillin, and fosfomycin and four types of heavy metals (mercury, chromium, copper, and zinc were carried out using disk diffusion and two-fold agar dilution method, respectively. Results: Three hundred isolates of A. hydrophila and E. tarda were successfully identified by biochemical tests. Antibiotic susceptibility testing results showed that 42.2% of the bacterial isolates were sensitive to compound sulfonamides, sulfamethoxazole, flumequine, oxytetracycline, doxycycline, and oxolinic acid. On the other hand, 41.6% of these isolates were resistant to novobiocin, ampicillin, spiramycin, and chloramphenicol, which resulted for multiple antibiotic resistance index values 0.416. Among tested heavy metals, bacterial isolates exhibited resistant pattern of Zn2+ > Cr6+ > Cu2+ > Hg2+. Conclusion: Results from this study indicated that A. hydrophila and E. tarda isolated from coinfected farmed red hybrid tilapia were multi-resistant to antibiotics and heavy metals. These resistant profiles could be useful information to fish farmers to avoid unnecessary use of

  2. A foodborne outbreak of Aeromonas hydrophila in a college, Xingyi City, Guizhou, China, 2012

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    Guang Zeng

    2012-12-01

    Full Text Available Background: On 12 May 2012, over 200 college students with acute diarrhoea were reported to the Guizhou Center for Disease Control and Prevention. We conducted an investigation to identify the agent and mode of transmission and to recommend control measures.Methods: A suspected case was a person at the college with onset of more than two of the following symptoms: diarrhoea (more than three loose stools in 24 hours, abdominal pain, vomiting or fever (> 37.5C between 6 and 15 May 2012. A confirmed case also had a positive Aeromonas hydrophila culture from a stool sample. A retrospective-cohort study of 902 students compared attack rates (AR by dining place, meals and food history. We reviewed the implicated premise, its processes and preparation of implicated food.Results: We identified 349 suspected cases (AR = 14% and isolated Aeromonas hydrophila from three stools of 15 cases. Students who ate in cafeteria A were more likely to be ill compared to those eating in other places (relative risk [RR]: 3.1, 95% confidence interval [CI]: 2.0–4.8. The cohort study implicated cold cucumber (RR: 2.6, 95% CI: 2.0–3.3 and houttuynia dishes (RR: 1.8, 95% CI: 1.4–2.3. Environmental investigation showed that vegetables were washed in polluted water from a tank close to the sewage ditch, then left at 30°C for two hours before serving. The Escherichia coli count of the tank was well above the standard for drinking water.Conclusion: This outbreak of Aeromonas hydrophila was most probably caused by salad ingredients washed in contaminated tank water. We recommended enhancing training of foodhandlers, ensuring tanks and sewerage systems comply with appropriate standards and adequate monitoring of drinking water sources.

  3. Functional genomic characterization of virulence factors from necrotizing fasciitis-causing strains of Aeromonas hydrophila.

    Science.gov (United States)

    Grim, Christopher J; Kozlova, Elena V; Ponnusamy, Duraisamy; Fitts, Eric C; Sha, Jian; Kirtley, Michelle L; van Lier, Christina J; Tiner, Bethany L; Erova, Tatiana E; Joseph, Sandeep J; Read, Timothy D; Shak, Joshua R; Joseph, Sam W; Singletary, Ed; Felland, Tracy; Baze, Wallace B; Horneman, Amy J; Chopra, Ashok K

    2014-07-01

    The genomes of 10 Aeromonas isolates identified and designated Aeromonas hydrophila WI, Riv3, and NF1 to NF4; A. dhakensis SSU; A. jandaei Riv2; and A. caviae NM22 and NM33 were sequenced and annotated. Isolates NF1 to NF4 were from a patient with necrotizing fasciitis (NF). Two environmental isolates (Riv2 and -3) were from the river water from which the NF patient acquired the infection. While isolates NF2 to NF4 were clonal, NF1 was genetically distinct. Outside the conserved core genomes of these 10 isolates, several unique genomic features were identified. The most virulent strains possessed one of the following four virulence factors or a combination of them: cytotoxic enterotoxin, exotoxin A, and type 3 and 6 secretion system effectors AexU and Hcp. In a septicemic-mouse model, SSU, NF1, and Riv2 were the most virulent, while NF2 was moderately virulent. These data correlated with high motility and biofilm formation by the former three isolates. Conversely, in a mouse model of intramuscular infection, NF2 was much more virulent than NF1. Isolates NF2, SSU, and Riv2 disseminated in high numbers from the muscular tissue to the visceral organs of mice, while NF1 reached the liver and spleen in relatively lower numbers on the basis of colony counting and tracking of bioluminescent strains in real time by in vivo imaging. Histopathologically, degeneration of myofibers with significant infiltration of polymorphonuclear cells due to the highly virulent strains was noted. Functional genomic analysis provided data that allowed us to correlate the highly infectious nature of Aeromonas pathotypes belonging to several different species with virulence signatures and their potential ability to cause NF.

  4. Emerging extra-intestinal infections with Aeromonas hydrophila in coastal region of southern Karnataka

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    Mukhopadhyay C

    2008-01-01

    Full Text Available Background: Aeromonas species are gram-negative rods usually isolated from the gastrointestinal tract. They have been occasionally reported as a cause of extra-intestinal infections such as cellulitis, cholangitis, necrotizing fascitis, meningitis, bacteremia, or peritonitis in both immunocompetent and immunocompromised patients . Aim: To determine the role and possible pathogenesis of Aeromonas in extra-intestinal infections.Settings and Design: Retrospective analysis carried out at Kasturba Hospital Manipal, Karnataka in the months of January and February 2007. Materials and Methods: Clinical manifestations and management of eight cases of extra-intestinal infections caused by A. hydrophila , from the south Karnataka coastal region were reviewed. The isolates were identified with the help of biochemical tests using standard guidelines.Results: All patients acquired Aeromonas infections in the community. Five (62.5% had underlying illnesses, such as liver disease, diabetes mellitus or malignancy. Five (62.5% had polymicrobial infections, and three (37.5% were complicated with bacteremia. These included three patients with ulcers or abscess over the lower leg, two with cellulitis due to snake bite and one each with pelvic inflammatory disease, spontaneous bacterial peritonitis and pneumonia. A. hydrophila was found to be a causative agent of pelvic inflammatory disease or cellulitis following sea snake bite, and such a clinical scenario has not been previously described. Seven patients survived the illness. Conclusions: Isolation of A. hydrophila from extra-intestinal specimens demands utmost clinical and microbiological vigilance in diagnosis, since the organism can cause serious infections among immunocompromised as well as immunocompetent individuals.

  5. Diabetic Foot Due to Aeromonas Hydrophila and Pseudomonas Oryzihabitans: A Case Report

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    Aysel Talan

    2014-09-01

    Full Text Available Foot infections are the most common cause of amputations in diabetic patients. The main predisposing reasons for the development of foot ulcers and subsequent infection in diabetic patients are sensory neuropathy, vascular insufficiency and immune system abnormalities due to hyperglycemia. Limb-threatening infections are often polymicrobial. Staphylococcus aureus, group B streptococci, enterococci and facultative gram-negative bacilli are the most common pathogens. Here, we present two cases of diabetic foot infected by extremely rare microorganisms: Aeromonas hydrophila, and Pseudomonas (Flavimonas oryzihabitans. Turk Jem 2014; 18: 100-102

  6. Taxonomía y epidemiología del género aeromonas

    OpenAIRE

    Alperi Vega, Anabel

    2009-01-01

    Durante la presente tesis doctoral se ha establecido la presencia de variabilidad interoperónica en el gen ARNr 16S de Aeromonas y observado que ésta afectaba a la taxonomía del género, limitando la identificación de A. caviae, A. media y A. veronii. La secuenciación del gen rpoD permitió identificar las cepas con variabilidad interoperónica a nivel de especie y reconocer 5 nuevas especies del género: A. fluvialis, A. taiwanensis, A. sanarelii, A. piscicola y A. rivuli. En colaboración con d...

  7. Rapid biochemical screening for Salmonella, Shigella, Yersinia, and Aeromonas isolates from stool specimens.

    Science.gov (United States)

    De Ryck, R; Struelens, M J; Serruys, E

    1994-06-01

    Four screens for the rapid (4 to 6 h) biochemical detection of pathogens from enteric isolation media are described. The Salmonella screen consisted of Kligler iron agar (KIA), motility-indole-urea-tryptophan-deamination semisolid medium (MIU-TDA), and the o-nitrophenyl-beta-D-galactopyranoside (ONPG) test; the Shigella screen consisted of KIA, MIU-TDA, the ONPG test, and the lysine decarboxylation-indole test; the Yersinia screen consisted of a rhamnose broth; the Aeromonas screen consisted of a xylose agar plate. When tested on 2,102 fresh isolates and 71 stock strains, the screens correctly detected 212 enteric pathogens (sensitivity, 100%), with a specificity of 98.1%.

  8. Expression, purification, crystallization and preliminary X-ray analysis of Aeromonas hydrophilia metallo-[beta]-lactamase

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, N.; Toney, J.H.; Fitzgerald, P.M.D. (Merck)

    2010-07-20

    The CphA metallo-{beta}-lactamase from Aeromonas hydrophilia has been expressed, purified and crystallized by the hanging-drop vapor-diffusion method using ammonium sulfate as the precipitant. The crystals exhibit orthorhombic symmetry (P2{sub 1}2{sub 1}2), with unit-cell parameters a = 40.75, b = 42.05, c = 128.88 {angstrom}. There is one monomer in the asymmetric unit and the solvent content is estimated to be 44% by volume. A data set extending to 1.8 {angstrom} has been measured.

  9. Structure of the O-specific polysaccharide from the lipopolysaccharide of Aeromonas sobria strain Pt312.

    Science.gov (United States)

    Turska-Szewczuk, Anna; Pietras, Hubert; Duda, Katarzyna A; Kozińska, Alicja; Pękala, Agnieszka; Holst, Otto

    2015-02-11

    The O-specific polysaccharide (OPS) obtained by mild-acid degradation of the lipopolysaccharide from Aeromonas sobria strain Pt312 was studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, NOESY, 1H-detected 1H,13C HSQC, and HMBC experiments. The sequence of the sugar residues was determined using 1H,1H NOESY and 1H,13C HMBC experiments. It was found that the OPS was built up of disaccharide repeating units composed of GlcpNAc and non-stoichiometrically O-acetylated Rhap residues, and had the structure.

  10. Prevalence and diversity of Aeromonas and Vibrio spp. in coastal waters of Southern Italy

    DEFF Research Database (Denmark)

    Dumontet, S.; Krovacek, K.; Svenson, S.B.

    2000-01-01

    and A. caviae. Furthermore, the antibiotic resistance patterns of isolated bacteria showed the presence of a number of resistant strains among the isolates. In order to discriminate the isolates on the basis of their biochemical profiles and/or antibiotic resistance patterns, cluster analysis...... was carried out which showed that no unique assay could fully discern these isolates. However, the best discrimination resulted from complete pattern profile based on both biochemical profiles and antibiotic resistance patterns.......% of samples were positive for Vibrio spp. It was interesting to note that 38% of the positive stations for both Aeromonas and Vibrio spp. showed a fecal coliform contamination of water at bacterial indicators (such as fecal...

  11. Effect of the Glutaraldehyde on the Bacteriostatic and Bactericide of Aeromonas%戊二醛对气单胞菌的抑菌杀菌效果研究

    Institute of Scientific and Technical Information of China (English)

    谭凤霞; 陈和东; 叶聪

    2011-01-01

    [目的]研究戊二醛对气单胞菌的杀菌效果,为戊二醛在水产养殖上的合理使用提供依据.[方法]以气单胞菌属标准株ATCC7966和分离自养殖环境及患病鱼的气单胞菌为试验菌株,通过肉汤二倍稀释法研究.[结果]戊二醛在低浓度时能抑制气单胞菌的生长增殖,高浓度杀灭细菌,其对7株气单胞菌的最小抑菌浓度(MIC)均为7.8mg/L,其最小杀菌浓度为62.5 mg/L( ATCC7966、Aeromonas sp.T3、Aeromonas sp.T5、Aeromonas sp.T6)和125 mg/L( Aeromonas sp.T1、Aeromonas sp.T2、Aeromonas sp.T4).[结论]为戊二醛的合理使用提供一定的依据.%[Objective] The basis of the reasonable utilization of glutaraldehyde in aquaculture production was provided through the research on its effect on the bactericide of Aeromonas. [Method] The standard strain of Aeromonas - - ATCC7966 and the Aeromonas strain isolated from fish - raising environment or from diseased fish was taken as the tested strain and the efficacy of the glutaraldehyde on the bacteriostatic and bactericide of Aeromonas was determined with the method of double broth dilution. [ Results ] The results showed that the glutaraldehyde could inhibit the growth of bacterium at the low concentration and kill the bacterium at the high concentration. The minimal inhibitory concentration ( MIC) of glutaraldehyde to 7 Aeromonas strains was 7. 8mg/l and the minimal bactericidal concentration( MBC) of glutaraldehyde to 4 Aeromonas strains including ATCC7966, Aeromonas sp. T3, Aeromonas sp. T5 and Aeromonas sp. T6 was 62.5 mg/1 and 3 Aeromonas strains including Aeromonas sp. Tl, Aeromonas sp. T2 and Aeromonas sp. T4 was 125mg/l. [ Conclusion] The experimental results could provide the scientific basis of the reasonable application of glutaraldehyde.

  12. Pathogen Screening of Naturally Produced Yakima River Spring Chinook Smolts; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Joan B. (Washington Department of Fish and Wildlife, Olympia, WA)

    2003-05-01

    In 1999 the Cle Elem Hatchery began releasing spring chinook smolts into the upper Yakima River for restoration and supplementation. This project was designed to evaluate whether introduction of intensively reared hatchery produced smolts would impact the prevalence of specific pathogens in the naturally produced spring chinook smolts. Increases in prevalence of any of these pathogens could negatively impact the survival of these fish. Approximately 200 smolts were collected at the Chandler smolt collection facility on the lower Yakima River during 1998, 2000 and 2001 and 130 smolts were collected in 2002 for monitoring for specific pathogens. The pathogens monitored were infectious hematopoeitic necrosis virus, infectious pancreatic necrosis virus, viral hemorrhagic septicemia, Flavobacterium psychrophilum, Flavobacterium columnare, Aeromonas salmonicida, Yersinia ruckeri, Edwardsiella ictaluri, Renibacterium salmoninarum and Myxobolus cerebralis. In addition the fish were tested for Ceratomyxa shasta spores in 2000 and 2001 (a correction from the 2001 report). To date, the only changes have been in the levels the bacterial pathogens in the naturally produced smolts and they have been minimal. These changes are attributed to normal fluctuation of prevalence.

  13. Pathogen Screening of Naturally Produced Yakima River Spring Chinook Smolts; Yakima/Klickitat Fisheries Project Monitoring and Evaluation Report 6 of 7, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Joan B. (Washington Department of Fish and Wildlife, Olympia, WA)

    2004-05-01

    In 1999 the Cle Elum Hatchery began releasing spring chinook salmon smolts into the upper Yakima River to increase natural production. Part of the evaluation of this program is to monitor whether introduction of hatchery produced smolts would impact the prevalence of specific pathogens in the naturally produced spring chinook smolts. Increases in prevalence of any of these pathogens could negatively impact the survival of these fish. In 1998 and 2000 through 2003 naturally produced smolts were collected for monitoring at the Chandler smolt collection facility on the lower Yakima River. Smolts were collected from mid to late outmigration, with a target of 200 fish each year. The pathogens monitored were infectious hematopoeitic necrosis virus, infectious pancreatic necrosis virus, viral hemorrhagic septicemia virus, Flavobacterium psychrophilum, Flavobacterium columnare, Aeromonas salmonicida, Yersinia ruckeri, Edwardsiella ictaluri, Renibacterium salmoninarum and Myxobolus cerebralis. To date, only the bacterial pathogens have been detected and prevalences have been low. Prevalences have varied each year and these changes are attributed to normal fluctuation of prevalence. All of the pathogens detected are widely distributed in Washington State.

  14. Pathogen Screening of Naturally Produced Yakima River Spring Chinook Smolts; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Pearsons, Todd N.; Thomas, Joan B. (Washington Department of Fish and Wildlife, Olympia, WA)

    2003-01-01

    The change in pathogens prevalence to wild fish is probably the least studied ecological interaction associated with hatchery operations. In 1999, the Cle Elum Hatchery began releasing spring chinook smolts into the upper Yakima River to increase natural production. Part of the evaluation of this program is to evaluate whether introduction of hatchery produced smolts would impact the prevalence of specific pathogens in the naturally produced spring chinook smolts. Increases in prevalence of any of these pathogens could negatively impact the survival of these fish. Approximately 200 smolts were collected at the Chandler smolt collection facility on the lower Yakima River during 1998, 2000 and 2001 and monitored for specific pathogens. The pathogens monitored were infectious hematopoeitic necrosis virus, infectious pancreatic necrosis virus, viral hemorrhagic septicemia, Flavobacterium psychrophilum, Flavobacterium columnare, Aeromonas salmonicida, Yersinia ruckeri, Edwardsiella ictaluri, Renibacterium salmoninarum and Myxobolus cerebralis. In addition, the fish were tested for Ceratomyxa shasta spores in 2001. Not all testing has been completed for every year, but to date, there have only been minimal changes in levels of the bacterial pathogens in the naturally produced smolts. At this point, due to the limited testing so far, these changes are attributed to normal fluctuation of prevalence.

  15. Pathogen Screening of Naturally Produced Yakima River Spring Chinook Smolts; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2004-2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Joan B. (Washington Department of Fish and Wildlife, Olympia, WA)

    2005-05-01

    In the spring of 2004 naturally produced smolts outmigrating from the Yakima River Basin were collected for the sixth year of pathogen screening. This component of the evaluation is to monitor whether introduction of hatchery produced smolts would impact the prevalence of specific pathogens in the naturally produced spring chinook smolts. Increases in prevalence of any of these pathogens could negatively impact the survival of these fish. Since 1999 the Cle Elum Hatchery has been releasing spring chinook salmon smolts into the upper Yakima River to increase natural production. In 1998 and 2000 through 2004 naturally produced smolts were collected for monitoring at the Chandler smolt collection facility on the lower Yakima River. Smolts were collected from mid to late outmigration, with a target of 200 fish each year. The pathogens monitored were infectious hematopoeitic necrosis virus, infectious pancreatic necrosis virus, viral hemorrhagic septicemia virus, Flavobacterium psychrophilum, Flavobacterium columnare, Aeromonas salmonicida, Yersinia ruckeri, Edwardsiella ictaluri, Renibacterium salmoninarum and Myxobolus cerebralis. Of these pathogens, only R. salmoninarum was detected in very low levels in the naturally produced smolts outmigrating in 2004. To date, only bacterial pathogens have been detected and prevalences have been low. There have been small variations each year and these changes are attributed to normal fluctuations in prevalence. All of the pathogens detected are widely distributed in Washington State.

  16. Aeromonas species in stabilization ponds in the arid region of Marrakesh, Morocco, and relation to fecal-pollution and climatic factors.

    Science.gov (United States)

    Boussaid, A; Baleux, B; Hassani, L; Lesne, J

    1991-12-01

    During the period 12 July 1985 to 23 December 1987, water samples were collected in two-week intervals for estimates ofAeromonas species in a waste treatment system located in the arid region of Marrakech, Morocco. Fecal coliforms, temperature, and chemical oxygen demand were measured simultaneously withAeromonas species densities. Statistical methods were utilized to analyze the significance of average differences and temporal patterns ofAeromonas species numbers.Removal ofAeromonas in the whole system did not exceed 1.14 log.Aeromonas densities showed significantly higher resistance to the treatment process when compared with fecal coliforms; however, abundance of the two groups presented a similar seasonal change. The highest numbers occurred during the cold months, while the lowest appeared in the warm months. Statistical time-series analyses of the densities data showed the seasonal and cyclic distribution ofAeromonas in this treatment plant.These temporal changes were simultaneously observed in all the stations investigated and were negatively correlated with water temperature values.Aeromonas populations were dominated byA. caviae andA. hydrophila in the inlet samples. These two species were rapidly eliminated in the treatment plant. The temporal distribution ofA. caviae was similar to the change in densities ofAeromonas and fecal coliforms. The seasonal fluctuations of abundance ofAeromonas were probably related to this species, which dominated in the winter samples but dropped during the summer. Meanwhile,A. sobria dominated all the final effluent samples. This greater survival ofA. sobria and its known pathogenicity may limit the re-use of treated water for irrigation of fodder plants.

  17. Curvularia haloperoxidase: Antimicrobial activity and potential application as a surface disinfectant

    DEFF Research Database (Denmark)

    Hansen, E.H.; Albertsen, Line; Johansen, Charlotte

    2003-01-01

    , to antimicrobial compounds. The Curvularia haloperoxidase system caused several-log-unit reductions in counts of bacteria (Pseudomonas spp., Escherichia coli, Serratia marcescens, Aeromonas salmonicida, Shewanella putrefaciens, Staphylococcus epidermidis, and Listeria monocytogenes), yeasts (Candida sp...

  18. Baltic Salmon, Salmo salar, from Swedish River Lule Älv Is More Resistant to Furunculosis Compared to Rainbow Trout

    DEFF Research Database (Denmark)

    Holten-Andersen, Lars; Dalsgaard, Inger; Buchmann, Kurt

    2012-01-01

    Background: Furunculosis, caused by Aeromonas salmonicida, continues to be a major health problem for the growing salmonid aquaculture. Despite effective vaccination programs regular outbreaks occur at the fish farms calling for repeated antibiotic treatment. We hypothesized that a difference...

  19. Characterization of Virulence Properties of Aeromonas veronii Isolated from Diseased Gibel Carp (Carassius gibelio)

    Science.gov (United States)

    Sun, Jingjing; Zhang, Xiaojun; Gao, Xiaojian; Jiang, Qun; Wen, Yi; Lin, Li

    2016-01-01

    Aeromonas veronii is a kind of opportunistic pathogen to fish and humans, significantly impending aquaculture production. Recently, we isolated two A. veronii strains, named GYC1 and GYC2, from diseased Gibel carp (Carassius gibelio) in China. Based on gyrB (DNA gyrase B subunit) genes of GYC1 and GYC2, the constructed phylogenetic tree showed that the two strains were clustered with A. veronii. Sixteen virulence genes related to the pathogenicity of Aeromonas spp. were subjected to PCR assay. The genes of ompAI, ompAII, lafA, act, aer, fla, gcaT and acg were detected in the two strains, while genes of hly, ahp, lip, ast and alt were not detected. Additionally, genes eprCAI, ela and exu were only detected in the strain GYC1. Furthermore, the results of extracellular enzyme analysis revealed that the two isolates can produce hemolysin, caseinase, esterase, amylase and lecithinase, which were closely related to the pathogenicity of the two strains. However, the results showed that there was no gelatinase activity in either strain. According to the antibiotic resistant assay, the two strains were sensitive to cephalosporins and aminoglycosides, while they were resistant to penicillins and quinolones. Through this study, the virulence characteristics, including virulence genes and extracellular enzymes, the pathogenicity of A. veronii was clarified, enhancing the understanding about this pathogenic bacterium and providing the theoretical basis in disease control. PMID:27043558

  20. Bioremediation and Detoxification of Synthetic Wastewater Containing Triarylmethane Dyes by Aeromonas hydrophila Isolated from Industrial Effluent

    Directory of Open Access Journals (Sweden)

    Chimezie Jason Ogugbue

    2011-01-01

    Full Text Available Economical and bio-friendly approaches are needed to remediate dye-contaminated wastewater from various industries. In this study, a novel bacterial strain capable of decolorizing triarylmethane dyes was isolated from a textile wastewater treatment plant in Greece. The bacterial isolate was identified as Aeromonas hydrophila and was shown to decolorize three triarylmethane dyes tested within 24 h with color removal in the range of 72% to 96%. Decolorization efficiency of the bacterium was a function of operational parameters (aeration, dye concentration, temperature, and pH and the optimal operational conditions obtained for decolorization of the dyes were: pH 7-8, 35∘C and culture agitation. Effective color removal within 24 h was obtained at a maximum dye concentration of 50 mg/L. Dye decolorization was monitored using a scanning UV/visible spectrophotometer which indicated that decolorization was due to the degradation of dyes into non-colored intermediates. Phytotoxicity studies carried out using Triticum aestivum, Hordeum vulgare, and Lens esculenta revealed the triarylmethane dyes exerted toxic effects on plant growth parameters monitored. However, significant reduction in toxicity was obtained with the decolorized dye metabolites thus, indicating the detoxification of the dyes following degradation by Aeromonas hydrophila.

  1. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources

    Directory of Open Access Journals (Sweden)

    Olumide A. Odeyemi

    2017-01-01

    Full Text Available This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13, bivalve (n = 10, sea cucumber (n = 16 and sea water (n = 14 and resistance to 12 antibiotics – Tetracycline (30 μg, Kanamycin (30 μg, Oxytetracycline (30 μg, Ampicillin (10 μg, Streptomycin (10 μg, Gentamicin (10 μg, Sulphamethoxazole (25 μg, Nalixidic acid (30 μg, Trimethoprim (1.25 μg, Novobiocin (5 μg, Penicilin (10 μg and Chloramphenicol (10 μg was tested. The results obtained from this study reveal multi drug resistance pattern among the isolates. All the isolates were completely resistant to Ampicillin, Novobiocin, Sulphamethoxazole and Trimethoprim, respectively but susceptible to Tetracycline (100%, Kanamycin (5.7%, Gentamicin (5.7% and Oxytetracycline (24.5%. Antibiotics phenotyping of the bacteria revealed 21 different phenotypes among the isolates.

  2. Aeromonas punctata derived depolymerase that disrupts the integrity of Klebsiella pneumoniae capsule: optimization of depolymerase production.

    Science.gov (United States)

    Bansal, Shruti; Soni, Sanjeev Kumar; Harjai, Kusum; Chhibber, Sanjay

    2014-07-01

    Formation of dense, highly hydrated biofilm structures pose a risk for public and environmental health. Extracellular polymeric substances encompassing biofilms offer 1000-fold greater resistance as compared to the planktonic cells. Using enzymes as anti-biofouling agents, will improve penetration of antimicrobials and increase susceptibility of biofilms to components of immune system. The challenge of using enzymes derived from unrelated bacteria for the degradation of capsular matrix of Klebsiella pneumoniae has not been dealt in the past. Thus, statistical optimization was done to enhance depolymerase production by Aeromonas punctata, directed against the exopolysaccharide matrix of Klebsiella pneumoniae B5055, capable of substituting the available phage borne depolymerase enzyme. Optimization via central composite design (CCD) resulted in 16-fold enhancement in depolymerase yield (166.65 µmoles ml(-1)  min(-1) ) over unoptimized medium. Out of the 19 variables, media composition giving maximum expression levels of the enzyme consisted of 1 mg ml(-1) galactose and ammonium chloride, 1.5 mg ml(-1) each of capsular polysaccharide (CPS) and magnesium sulfate. Tryptic peptide analysis of the purified 29 kDa band by Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) showed a high homology with a protein of unknown function from Aeromonas cavaie Ae398. Further improvements in the enzyme can lead to its successful development as prophylactic and/or a therapeutic agent.

  3. sugE: A gene involved in tributyltin (TBT) resistance of Aeromonas molluscorum Av27.

    Science.gov (United States)

    Cruz, Andreia; Micaelo, Nuno; Félix, Vitor; Song, Jun-Young; Kitamura, Shin-Ichi; Suzuki, Satoru; Mendo, Sónia

    2013-01-01

    The mechanism of bacterial resistance to tributyltin (TBT) is still unclear. The results herein presented contribute to clarify that mechanism in the TBT-resistant bacterium Aeromonas molluscorum Av27. We have identified and cloned a new gene that is involved in TBT resistance in this strain. The gene is highly homologous (84%) to the Aeromonas hydrophila-sugE gene belonging to the small multidrug resistance gene family (SMR), which includes genes involved in the transport of lipophilic drugs. In Av27, expression of the Av27-sugE was observed at the early logarithmic growth phase in the presence of a high TBT concentration (500 μM), thus suggesting the contribution of this gene for TBT resistance. E. coli cells transformed with Av27-sugE become resistant to ethidium bromide (EtBr), chloramphenicol (CP) and tetracycline (TE), besides TBT. According to the Moriguchi logP (miLogP) values, EtBr, CP and TE have similar properties and are substrates for the sugE-efflux system. Despite the different miLogP of TBT, E. coli cells transformed with Av27-sugE become resistant to this compound. So it seems that TBT is also a substrate for the SugE protein. The modelling studies performed also support this hypothesis. The data herein presented clearly indicate that sugE is involved in TBT resistance of this bacterium.

  4. Detection and quantification of virulent Aeromonas hydrophila in channel catfish tissues following waterborne challenge.

    Science.gov (United States)

    Zhang, Dunhua; Moreira, Gabriel S A; Shoemaker, Craig; Newton, Joseph C; Xu, De-Hai

    2016-05-01

    The aim of this study was to understand the pathogenesis of motile aeromonas septicemia caused by an emergent, high virulent Aeromonas hydrophila (vAh) in channel catfish, Ictalurus punctatus Adipose fin clipped catfish were challenged with vAh using a waterborne challenge method, and the distribution of vAh over a time course was detected and quantified using real-time polymerase chain reaction. The results showed that 77.8% of fish died within 48 h post challenge with mean day to death of 1.5 days. At 2 h post challenge, vAh (inferred from genomic DNA copies or genome equivalents) was detected in all external and internal tissues sampled. Gill had the highest vAh cells at 1 h post challenge. Spleen harbored the most vAh cells among internal organs at 4 h post challenge. The tissues/organs with most vAh cells detected at 8 h post challenge were adipose fin, blood, intestine, kidney and skin, while liver showed the highest vAh cells at 24 h post challenge. These results suggest that vAh was able to rapidly proliferate and spread, following wound infection, through the fish blood circulation system and cause mortality within 8-24 h.

  5. Characterization of Virulence Properties of Aeromonas veronii Isolated from Diseased Gibel Carp (Carassius gibelio).

    Science.gov (United States)

    Sun, Jingjing; Zhang, Xiaojun; Gao, Xiaojian; Jiang, Qun; Wen, Yi; Lin, Li

    2016-04-01

    Aeromonas veronii is a kind of opportunistic pathogen to fish and humans, significantly impending aquaculture production. Recently, we isolated two A. veronii strains, named GYC1 and GYC2, from diseased Gibel carp (Carassius gibelio) in China. Based on gyrB (DNA gyrase B subunit) genes of GYC1 and GYC2, the constructed phylogenetic tree showed that the two strains were clustered with A. veronii. Sixteen virulence genes related to the pathogenicity of Aeromonas spp. were subjected to PCR assay. The genes of ompAI, ompAII, lafA, act, aer, fla, gcaT and acg were detected in the two strains, while genes of hly, ahp, lip, ast and alt were not detected. Additionally, genes eprCAI, ela and exu were only detected in the strain GYC1. Furthermore, the results of extracellular enzyme analysis revealed that the two isolates can produce hemolysin, caseinase, esterase, amylase and lecithinase, which were closely related to the pathogenicity of the two strains. However, the results showed that there was no gelatinase activity in either strain. According to the antibiotic resistant assay, the two strains were sensitive to cephalosporins and aminoglycosides, while they were resistant to penicillins and quinolones. Through this study, the virulence characteristics, including virulence genes and extracellular enzymes, the pathogenicity of A. veronii was clarified, enhancing the understanding about this pathogenic bacterium and providing the theoretical basis in disease control.

  6. Characterization and Expression of Outer Membrane Protein AI Gene of Aeromonas veronii

    Institute of Scientific and Technical Information of China (English)

    Wang Hai-juan; Wang Li

    2015-01-01

    The outer membrane protein, ompA, ofAeromonas veronii has a role in the virulence of the organism and is a potential candidate for vaccine development. In this study, ompAⅠofAeromonas veronii strain WA106 was cloned and sequenced, then, it was expressed inEscherichia coli BL21. The nucleotide sequence of ompAⅠgene was 1 023 base pairs (GenBank Accession NO.KC748024), which showed 100% homology with that ofA. veronii (NO.AB290200.1). This predicted protein was composed of 340 amino acid residues. Its molecular weight was 35.78 ku and isoelectric point was 5.18. The protein was a hydrophilic protein containing alpha helix and random coil with percentage of 35.0% and 49.7%, respectively. The tertiary structure, quaternary structure prediction showed that ompAⅠprotein contained two peptide chains. SDS-PAGE showed that the actual value of the fusion protein was consistent with the expected result. It will facilitate further study of the role of ompAⅠprotein.

  7. Distribution of 13 virulence genes among clinical and environmental Aeromonas spp. in Western Australia.

    Science.gov (United States)

    Aravena-Román, M; Inglis, T J J; Riley, T V; Chang, B J

    2014-11-01

    We evaluated the pathogenic potential of 98 clinical and 31 environmental Aeromonas isolates by detecting the presence of 13 virulence genes using a polymerase chain reaction (PCR)-based method. The majority (96 %) of the strains contained at least one of the virulence genes. The overall distribution was aerA/haem (77 %), alt (53 %), lafA (51 %), ast (39 %), flaA (32 %), aspA (29 %), vasH (26 %), ascV (16 %) and aexT (13 %). No amplification products were detected for the genes encoding a bundle-forming pilus (BfpA and BfpG) or a Shiga-like toxin (stx-1 and stx-2). Five or more virulence genes were detected in 42 % of environmental and 24 % of clinical isolates. Among the major species, 48 % of A. hydrophila and 42 % of A. dhakensis isolates harboured five or more virulence genes compared with 19 % in A. veronii bv. sobria and none in A. caviae isolates. Our results suggest that, in Western Australia, strains of A. dhakensis and A. hydrophila are potentially more virulent than those of A. veronii bv. sobria and A. caviae, although the pathogenic potential of Aeromonas spp. is probably strain- rather than species-dependent.

  8. In Vitro Phytochemical And Antibacterial Activity Test On Temu Putih Extract Curcuma Zedoaria Against Aeromonas Hydrophila

    Directory of Open Access Journals (Sweden)

    Dimas Galang Prakosa

    2015-08-01

    Full Text Available Aeromonas hydrophila bacterium is one of the bacteria which frequently attack fresh water aquaculture and cause the farmer experience terrible loss. In order to cope with the diseases caused by A. hydrophila bacteria the usage of natural antibacteria was more recommended as it does not give negative effects to the environment. One natural antibacteria which can be used against A. hydrophila is from the white turmeric extract Curcuma zedoaria. The aim of this study is to know the active compound content in white turmeric Curcuma zedoaria to determine the most effective solvent and the effective maceration duration to extract Curcuma zedoaria as antibacteria against Aeromonas hydrophila using disc diffusion method. The study used descriptive and experimental method with treatments to 3 different solvents ethanol ethyl acetate and chloroform and 3 repetitions. The data acquired from the results of the study were then analyzed descriptively. Results showed that Curcuma zedoaria extract from the phytochemical test contained saponins alkaloid and flavonoid. The best solvent was ethyl acetate with maceration for 2x24 hours and inhibition area width 11.34 mm.

  9. Aeromonas sobria serine protease (ASP): a subtilisin family endopeptidase with multiple virulence activities.

    Science.gov (United States)

    Imamura, Takahisa; Murakami, Yoji; Nitta, Hidetoshi

    2017-09-26

    Aeromonas sobria serine protease (ASP) is secreted from Aeromonas sobria, a pathogen causing gastroenteritis and sepsis. ASP resembles Saccharomyces cerevisiae Kex2, a member of the subtilisin family, and preferentially cleaves peptide bonds at the C-terminal side of paired basic amino acid residues; also accepting unpaired arginine at the P1 site. Unlike Kex2, however, ASP lacks an intramolecular chaperone N-terminal propeptide, instead utilizes the external chaperone ORF2 for proper folding, therefore, ASP and its homologues constitute a new subfamily in the subtilisin family. Through activation of the kallikrein/kinin system, ASP induces vascular leakage, and presumably causes edema and septic shock. ASP accelerates plasma clotting by α-thrombin generation from prothrombin, whereas it impairs plasma clottability by fibrinogen degradation, together bringing about blood coagulation disorder that occurs in disseminated intravascular coagulation, a major complication of sepsis. From complement C5 ASP liberates C5a that induces neutrophil recruitment and superoxide release, and mast cell degranulation, which are associated with pus formation, tissue injury and diarrhea, respectively. Nicked two-chain ASP also secreted from A. sobria is more resistant to inactivation by α2-macroglobulin than single-chain ASP, thereby raising virulence activities. Thus, ASP is a potent virulence factor and may participate in the pathogenesis of A. sobria infection.

  10. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources.

    Science.gov (United States)

    Odeyemi, Olumide A; Ahmad, Asmat

    2017-01-01

    This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13), bivalve (n = 10), sea cucumber (n = 16) and sea water (n = 14) and resistance to 12 antibiotics - Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole (25 μg), Nalixidic acid (30 μg), Trimethoprim (1.25 μg), Novobiocin (5 μg), Penicilin (10 μg) and Chloramphenicol (10 μg) was tested. The results obtained from this study reveal multi drug resistance pattern among the isolates. All the isolates were completely resistant to Ampicillin, Novobiocin, Sulphamethoxazole and Trimethoprim, respectively but susceptible to Tetracycline (100%), Kanamycin (5.7%), Gentamicin (5.7%) and Oxytetracycline (24.5%). Antibiotics phenotyping of the bacteria revealed 21 different phenotypes among the isolates.

  11. Evidence for bacterial chemotaxis to cyanobacteria from a radioassay technique. [Lyngbya birgei; Aphanizomenon flos-aquae; Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Kangatharalingam, N.; Wang, Lizhu; Priscu, J.C. (Montana State Univ., Bozeman (USA))

    1991-08-01

    Lyngbya birgei and Aphanizomenon flos-aquae elicited a significant chemotactic attraction of Aeromonas hydrophila compared with controls lacking cyanobacteria. There was a positive exponential relationship between biomass (chlorophyll a) of L. birgei and A. flos-aquae and chemotactic attraction of A. hydrophila. The assay equipment was simple and reliable and could be used to study bacterial chemotaxis in other species in situ.

  12. Antibiogram, Adhesive Characteristics, and Incidence of Class 1 Integron in Aeromonas Species Isolated from Two South African Rivers

    Directory of Open Access Journals (Sweden)

    Isoken H. Igbinosa

    2013-01-01

    Full Text Available Aeromonas species are well distributed in freshwater environments, and their natural susceptibility to antimicrobials renders them interesting candidates for the survey of antimicrobial resistance in freshwater milieu. Water samples were collected from Kat and Tyume rivers in the Eastern Cape province of South Africa, and a total of 45 isolates identified as Aeromonas species were recovered from the two rivers. All Aeromonas isolates were resistant to oxacillin, penicillin, clindamycin, cephalothin, vancomycin, and rifamycin, while appreciable susceptibilities (89.3 : 94.1%, 82.1 : 94.1%, 85.7 : 88.2%, and 92.9 : 88.2% were observed against ciprofloxacin, chloramphenicol, nitrofurantoin, and gentamicin from Kat and Tyume rivers, respectively. Multiple antibiotic resistance (MAR indices ranged from 0.016 to 0.044 for the two rivers. Class 1 integron was detected in about 20% of the isolates, and all the isolates except one showed ability to produce biofilm in vitro as weak producers (53.33%, moderate producers (15.56%, and strong producers (28.9%. This investigation provides a baseline data on antibiotic resistance as well as the adhesive characteristics of Aeromonas isolates from Tyume and Kat rivers in the Eastern Cape province of South Africa.

  13. Chicken-type lysozyme in channel catfish: Expression analysis, lysozyme activity and efficacy as immunostimulant against Aeromonas hydrophila infection

    Science.gov (United States)

    To understand whether chicken-type lysozyme (Lys-c) in channel catfish was induced by infection of Aeromonas hydrophila, the transcriptional levels of Lys-c in skin, gut, liver, spleen, posterior kidney, and blood cells in healthy channel catfish was compared to that in channel catfish infected with...

  14. Vaccination of channel catfish with extracellular products of Aeromonas hydrophila provides protection against infection by the pathogen

    Science.gov (United States)

    Aeromonas hydrophila, a Gram-negative bacterium, is one of the economically-important pathogens in modern aquaculture. Among various traits, extracellular products (ECP) secreted by the bacterium are considered to be essential factors for virulence. Whether vaccination with the ECP could produce imm...

  15. Inventarisatie van Aeromonas spp. in het drinkwater van 21 pompstations in de periode september 1985-december 1986 (deel II)

    NARCIS (Netherlands)

    Versteegh JFM; During M; Havelaar AH

    1987-01-01

    In de periode september 1985-december 1986 is in samenwerking met een aantal drinkwaterbedrijven een inventariserend onderzoek uitgevoerd naar het voorkomen van Aeromonas-bacterien in verschillende typen drinkwater geproduceerd op 21 drinkwaterpompstations. Nadat in de loop van het onderzoek duidel

  16. Degradation of chitin and chitosan by a recombinant chitinase derived from a virulent Aeromonas hydrophila isolated from diseased channel catfish

    Science.gov (United States)

    A chitinase was identified in extracellular products of a virulent Aeromonas hydrophila isolated from diseased channel catfish (Ictalurus punctatus). Bioactive recombinant chitinase (rChi-Ah) was produced in Escherichia coli. Purified rChi-Ah had optimal activity at temperature of 42°C and pH 6.5. T...

  17. Antibiogram, adhesive characteristics, and incidence of class 1 integron in Aeromonas species isolated from two South African rivers.

    Science.gov (United States)

    Igbinosa, Isoken H; Chigor, Vincent N; Igbinosa, Etinosa O; Obi, Lawrence C; Okoh, Anthony I

    2013-01-01

    Aeromonas species are well distributed in freshwater environments, and their natural susceptibility to antimicrobials renders them interesting candidates for the survey of antimicrobial resistance in freshwater milieu. Water samples were collected from Kat and Tyume rivers in the Eastern Cape province of South Africa, and a total of 45 isolates identified as Aeromonas species were recovered from the two rivers. All Aeromonas isolates were resistant to oxacillin, penicillin, clindamycin, cephalothin, vancomycin, and rifamycin, while appreciable susceptibilities (89.3 : 94.1%, 82.1 : 94.1%, 85.7 : 88.2%, and 92.9 : 88.2%) were observed against ciprofloxacin, chloramphenicol, nitrofurantoin, and gentamicin from Kat and Tyume rivers, respectively. Multiple antibiotic resistance (MAR) indices ranged from 0.016 to 0.044 for the two rivers. Class 1 integron was detected in about 20% of the isolates, and all the isolates except one showed ability to produce biofilm in vitro as weak producers (53.33%), moderate producers (15.56%), and strong producers (28.9%). This investigation provides a baseline data on antibiotic resistance as well as the adhesive characteristics of Aeromonas isolates from Tyume and Kat rivers in the Eastern Cape province of South Africa.

  18. DISTRIBUTION OF SIX VIRULENCE FACTORS IN AEROMONAS SPECIES ISOLATED FROM US DRINKING WATER UTILITIES: A PCR IDENTIFICATION

    Science.gov (United States)

    Surveys of finished drinking water conducted by the U.S. EPA during 2000-2001, revealed 7 out of 16 water utilities encompassing four states, were contaminated with Aeromonas species. A Polymerase Chain reaction (PCR) based genetic characterization determined the presence of six...

  19. Inventarisatie van Aeromonas spp. in het drinkwater van 21 pompstations in de periode september 1985-december 1986 (deel I)

    NARCIS (Netherlands)

    Versteegh JFM; During M; Havelaar AH

    1987-01-01

    In de periode september 1985-december 1986 is in samenwerking met een aantal drinkwaterbedrijven een inventariserend onderzoek uitgevoerd naar het voorkomen van Aeromonas-bacterien in verschillende typen drinkwater geproduceerd op 21 drinkwaterpompstations. Nadat in de loop van het onderzoek duidel

  20. Draft genome sequence of Pseudomonas mosselii Gil3, isolated from catfish and antagonistic against hypervirulent Aeromonas hydrophila

    Science.gov (United States)

    Pseudomonas mosselii Gil3 was isolated from a catfish that survived from lethal challenge with hypervirulent Aeromonas hydrophila (vAh). When assayed in vitro, the bacterium showed antagonism against vAh. Sequence analysis revealed that the genome of P. mosselii Gil3 encodes numerous aromatic metabo...

  1. Aeromonas species isolated from PINTADO fish (Pseudoplatystoma sp: virulence factors and drug susceptibility

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Mores Rall

    1998-09-01

    Full Text Available Aeromonas has been described as an emergent foodborne pathogen of increasing importance. In this study, we report that 48% of 50 Pintado fish samples collected at the retail market of São Paulo city were positive for Aeromonas sp, as detected by the direct plating method. When the presence/absence method was used, the positivity was 42%. A. caviae was the most frequent species, followed by A. hydrophila and A. sobria. Production of cytotoxic enterotoxin, observed in suckling mouse assay, was detected in 67% of A. sobria strains, in 60% of A. hydrophila strains and in 40% of A. caviae strains. In vitro tests, performed with HEp-2 cells, showed that 88% of A. hydrophila, 27% of A. sobria and 13% of A. caviae strains were positive for this toxin. The in vivo production of cytotonic enterotoxin, tested after heating the filtrates at 56ºC for 20 minutes, was detected in 17% of A. sobria, in 10% of A. caviae and in none of A. hydrophila strains in vivo. All analyzed strains did not alter HEp-2 cells. 20% and 16% of A. sobria and A. caviae isolates, respectively, presented capacity to adhere to HEp-2 cells. In counterpart, invasion of HEp-2 cells was not observed in any isolate. The Aeromonas isolates were sensitive to the majority of the antimicrobiol agents tested.Bactérias do gênero Aeromonas têm sido descritas como patógenos emergentes de importância crescente em alimentos. Neste estudo, relatamos que 48% das amostras de peixe "Pintado" coletado no comércio de São Paulo, foram positivas para Aeromonas sp quando isoladas pelo método de plaqueamento direto. Quando o método Presença/Ausência foi utilizado, a porcentagem de positividade foi de 42%. A. caviae foi a espécie mais freqüente, seguida por A. hydrophila e A. sobria. Produção de enterotoxina citotóxica, determinada em camundongos recém-nascidos, foi observada em 67% das cepas de A. sobria, em 60% das de A. hydrophila e em 40% das de A. caviae. No teste in vitro em c

  2. The immunocross-reaction between pathogenic Aeromonas hydrophila isolated from Siberian sturgeon Acipenser baerii and other three Aeromonas strains%西伯利亚鲟嗜水气单胞菌与其它3株气单胞菌间的免疫交叉反应

    Institute of Scientific and Technical Information of China (English)

    姜有声; 杨倩; 杨先乐; 吕利群; 邱军强

    2012-01-01

    The immunological characteristics of four Aeromonas strains like pathogenic bacteria strain Xl(Aeromonas hydrophlia) isolated from Siberian sturgeon (Acipenser baerii) suffering with bacterial septicaemia, pathogenic bacteria strain XL2-T strain (Aeromonas caviae ) isolated from the sturgeon septicemia, pathogenic strain Wl (Aeromonas sobria) and non-pathogenic M3 strain (Aeromonas hydrophlia) , were detected through the cross-reactions between four Aeromonas strains and antiserums by indirect immunofluoresence assay. The results showed that the pathogenic XI strain, XL2 -T strain and Wl strain had strong cross reactions, and weak cross reactions were found on non-pathogenic M3 strain with other three pathogenic strains.%采用间接免疫荧光技术分析了西伯利亚鲟细菌性败血症致病菌嗜水气单胞菌(Aeromonas hydrophlia)X1菌株、豚鼠气单胞菌(Aeromonas caviae)XL2-T菌株、致病性温和气单胞菌(Aeromonas sobria)W1菌株与无致病性嗜水气单胞菌(Aeromonas hydrophlia)M3菌株等水产养殖主要病原菌与抗血清之间的免疫交叉反应.结果显示具有致病性的同属菌株X1菌株、XL2-T菌株、W1菌株交叉反应程度较大,说明这3株菌表面存在较多相同抗原决定簇.而无致病性菌株M3与其他3株致病性菌株免疫交叉反应程度较小.

  3. Molecular characterization of antibiotic resistance in Pseudomonas and Aeromonas isolates from catfish of the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nguyen, Hoang Nam Kha; Van, Thi Thu Hao; Nguyen, Huu Thinh; Smooker, Peter M; Shimeta, Jeff; Coloe, Peter J

    2014-07-16

    A collection of 116 motile Pseudomonas spp. and 92 Aeromonas spp. isolated from 15 Vietnamese intensive catfish farms was analyzed to examine the molecular antibiotic resistance characteristics and the transferability of resistance markers within and between species. High levels of resistance to ampicillin, trimethoprim/sulfamethoxazole, nalidixic acid, chloramphenicol, and nitrofurantoin were observed. The percentage of multiple drug resistance of Pseudomonas spp. and Aeromonas spp. isolates was 96.6% and 61.9%, respectively. The multiple antibiotic resistance (MAR) index mean values of 0.457 and 0.293 of Pseudomonas and Aeromonas isolates, respectively, indicated that these isolates were exposed to high risk sources of contamination where antibiotics were commonly used. Approximately 33% of Pseudomonas spp. and 28% of Aeromonas spp. isolates from catfish contained class 1 integrons, but no class 2 integrons were detected. Several common resistance genes including aadA, dfrA and catB were harbored in class 1 integrons. Large plasmids (>55 kb) were frequently detected in 50% and 71.4% of the plasmids extracted from Pseudomonas and Aeromonas isolates, respectively. Conjugation and transformation experiments demonstrated the successful transfer of all or part of the resistance phenotypes of catfish isolates to the recipient strains, including laboratory strains and strains isolated from this study. These results highlight the likely role of catfish bacteria as a reservoir of antibiotic resistant, Gram-negative bacteria harboring a pool of mobile genetic elements that can readily be transferred intra- and interspecies. To our knowledge, this is the first report on molecular characterization of antibiotic resistance of bacteria isolated from catfish in Vietnam.

  4. Distribution and phenotypic and genotypic detection of a metallo-β-lactamase, CphA, among bacteraemic Aeromonas isolates.

    Science.gov (United States)

    Wu, Chi-Jung; Chen, Po-Lin; Wu, Jiunn-Jong; Yan, Jing-Jou; Lee, Chin-Chi; Lee, Hsin-Chun; Lee, Nan-Yao; Chang, Chia-Ming; Lin, Yu-Tzu; Chiu, Yen-Cheng; Ko, Wen-Chien

    2012-05-01

    The objectives of the study were to investigate the distribution of cphA-related genes (cphA) encoding a CphA metallo-β-lactamase (MBL) among 51 consecutive Aeromonas blood isolates and to compare different phenotypic methods for detecting CphA. The presence of cphA was detected by PCR. Four phenotypic methods, the imipenem-EDTA combined disc test, imipenem-EDTA MBL Etest, agar dilution test and modified Hodge test (MHT), were used to detect imipenem susceptibility and MBL production. The results showed that 35 (69%) blood isolates had cphA. All (100%) of 16 Aeromonas aquariorum isolates and 12 Aeromonas veronii isolates, and 4 (80%) of 5 Aeromonas hydrophila isolates, carried cphA, but none of 15 Aeromonas caviae isolates did. With the standard inocula, irrespective of the presence or absence of cphA, all but one (50, 98%) isolates were susceptible to imipenem tested by disc diffusion, Etest and agar dilution (10(4) c.f.u. spot inocula), and did not exhibit MBL production by the imipenem-EDTA combined disc test and MBL Etest. By the agar dilution test using large inocula (10(7) c.f.u.), 34 (97%) of 35 cphA(+) isolates had imipenem MICs of ≥16 µg ml(-1), higher than the susceptible breakpoint (4 µg ml(-1)), and demonstrated positive results for the MHT, while one cphA(+) and all 17 cphA(-) isolates had imipenem MICs of ≤4 µg ml(-1). In conclusion, the distribution of cphA among aeromonads is species-specific, found in A. aquariorum, A. veronii and A. hydrophila, and the MHT may be a phenotypic screening test for CphA production.

  5. Hematologia e sinais clínicos de Piaractus mesopotamicus infectados experimentalmente com Aeromonas hydrophila = Hematology and clinical signs of Piaractus mesopotamicus experimentally infected with Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Flávio Ruas Moraes

    2009-01-01

    Full Text Available Este ensaio teve como objetivo avaliar as respostas hematológicas e a ocorrência de sinais clínico-patológicos de Piaractus mesopotamicus infectados experimentalmente por Aeromonas hydrophila. Foram utilizados 324 pacus, P. mesopotamicus, com peso de 102,84 ±27,1 g, distribuídos em 27 caixas de 300 L de capacidade, sendo 14 peixes por caixa. Os peixes foram mantidos nas caixas durante um mês, recebendo dieta balanceada, período em que se evitou qualquer tipo de manejo estressante. Passado esse período, foram infectadoscom 6 x 106 UFC de A. hydrophila, injetada via intraperitoneal. As coletas e análises de sangue foram realizadas 24h antes da infecção experimental e 24h após a infecção. Os resultados permitem concluir que a infecção por A. hydrophila em P. mesopotamicus écaracterizada por escurecimento da derme e sinais clínicos-patológicos relacionados à hemorragia, anemia normocítica-hipocrômica, redução nos níveis de proteínas, globulinasplasmáticas e eosinófilos, leucopenia, linfopenia, trombocitopenia, neutrofilia e monocitose. The purpose of this study was to evaluate the hematological response and clinical sign of Piaractus mesopotamicus infected byAeromonas hydrophila. Were used 324 pacus, P. mesopotamicus weighing 102.84 ± 27.1 g distributed in 27 water tanks with 300 L of capacity, 14 fish per tank. The fish were kept in the water tanks during one month, receiving appropriate diet. In this period was avoidedstressing management. After this period, the fish were infected with 6 × 108 cfu of A. hydrophila fish-1, injected intraperitoneally. The blood collection was carried 24h before experimental infection and 24h after its. The A. hydrophila infection in P. mesopotamicus ischaracterized by dark skin and clinical signs related to hemorrhage, hypochromic normocytic anemia, decrease on plasmatic proteins and globulins levels, leucopenia, lymphopenia, thrombocytopenia, eosinophilia, neutrophilia and monocytosis.

  6. 聚维酮碘对气单胞菌的抑菌杀菌效果研究%Research on Bacteriostatic and Bactericidal Efficacy of Povidone Iodine on Aeromonas

    Institute of Scientific and Technical Information of China (English)

    谭凤霞

    2011-01-01

    [目的]研究聚维酮碘作为一种水产养殖上常用的消毒剂对气单胞菌的抑菌杀菌效果。[方法]以气单胞菌属标准株ATCC7966和分离自患病鱼及养殖环境的气单胞菌为试验菌株,通过肉汤二倍稀释法研究聚维酮碘的抑菌杀菌作用。[结果]聚维酮碘在低浓度时能抑制气单胞菌的生长增殖,高浓度时杀灭细菌,其对Aeromonas sp. T1、Aeromonas sp. T2、Aeromonas sp. T4菌株的最小抑菌浓度为125. 00mg/L,最小杀菌浓度为4.00g/L;其对ATCC7966、Aeromonas sp. T3、Aeromonas sp. T5、Aeromonas sp. T6菌株的最小抑菌浓度为250.00 mg/L,最小杀菌浓度为8.00 g/L。[结论]为聚维酮碘的合理使用提供了一定的依据。%[Objective] The aim of this study is to investigate the bacteriostatic and bactericidal efficacy of povidone iodine as one kind of disinfectants for aquaculture on Aeromonas.[Method] With the standard strain of Aeromonas ATCC7966 and the Aeromonas strains isolated from diseased fish or aquatic environment as the tested strains,the bacteriostatic and bactericidal efficacy of povidone iodine was studied by double broth dilution method.[Result] The povidone iodine could inhibit the growth of Aeromonas strains at lower concentration,and killed Aeromonas strains at higher concentration.The minimum bacteriostatic concentration(MIC) of povidone iodine on Aeromonas sp.T1,Aeromonas sp T2 and Aeromonas sp.T4 was 125.00 mg/L,and the minimum bactericidal concentration(MBC) was 4.00 g/L.Whereas,the minimum bacteriostatic concentration(MIC) of povidone iodine on ATCC7966,Aeromonas sp.T3,Aeromonas sp T5 and Aeromonas sp.T6 was 250.00 mg/L,and the minimum bactericidal concentration(MBC) was 8.00 g/L.[Conclusion] This study provides certain basis for reasonable application of povidone iodine.

  7. 聚维酮碘对气单胞菌的抑菌杀菌效果研究%Research on Bacteriostatic and Bactericidal Efficacy of Povidone Iodine on Aeromonas

    Institute of Scientific and Technical Information of China (English)

    谭凤霞

    2011-01-01

    [Objective] The aim of this study is to investigate the bacteriostatic and bactericidal efficacy of povidone iodine as one kind of disinfectants for aquaculture on Aeromonas. [ Method] With the standard strain of Aeromonas ATCC7966 and the Aeromonas strains isolated from diseased fish or aquatic environment as the tested strains, the bacteriostatic and bactericidal efficacy of povidone iodine was studied by double broth dilution method. [Result] The povidone iodine could inhibit the growth of Aeromonas strains at lower concentration, and killed Aeromonas strains at higher concentration. The minimum bacteriostatic concentration (MIC) of povidone iodine on Aeromonas sp. T1, Aeromonas sp. T2 and Aeromonas sp. T4 was 125.00 mg/L, and the minimum bactericidal concentration (MBC) was4.00 g/L. Whereas, the minimum bacteriostatic concentration (MIC) of povidone iodine on ATCC7966, Aeromonas sp. T3, Aeromonas sp. T5 and Aeromonas sp. T6 was 250.00 mg/L, and the minimum bactericidal concentration (MBC) was 8.00 g/L. [ Conclusion] This study provides certain basis for reasonable application of povidone iodine.%[目的]研究聚维酮碘作为一种水产养殖上常用的消毒剂对气单胞菌的抑菌杀菌效果.[方法]以气单胞菌属标准株ATCC7966和分离自患病鱼及养殖环境的气单胞菌为试验菌株,通过肉汤二倍稀释法研究聚维酮碘的抑菌杀菌作用.[结果]聚维酮碘在低浓度时能抑制气单胞菌的生长增殖,高浓度时杀灭细菌,其对Aeromonas sp.T1、Aeromonas sp.T2、Aeromonas sp.T4菌株的最小抑菌浓度为125.00 mg/L,最小杀菌浓度为4.00 g/L;其对ATCC7966、Aeromonas sp.T3、Aeromonas sp.T5、Aeromonas sp.T6菌株的最小抑菌浓度为250.00mg/L,最小杀菌浓度为8.00g/L.[结论]为聚维酮碘的合理使用提供了一定的依据.

  8. Classification of a hypervirulent Aeromonas hydrophila pathotype responsible for epidemic outbreaks in warm-water fishes

    Directory of Open Access Journals (Sweden)

    Cody Robert Rasmussen-Ivey

    2016-10-01

    Full Text Available Lineages of hypervirulent Aeromonas hydrophila (vAh are the cause of persistent outbreaks of motile Aeromonas septicemia in warm-water fishes worldwide. Over the last decade, in the People’s Republic of China and in the United States, this virulent lineage of A. hydrophila has resulted in annual losses of millions of tons of farmed carp and catfish. Multiple lines of evidence indicate that US catfish and Asian carp isolates of A. hydrophila affiliated with sequence type 251 (ST251 share a recent common ancestor. To address the genomic context for the putative intercontinental transfer and subsequent geographic spread of this pathogen, we conducted a core genome phylogenetic analysis on 61 Aeromonas spp. genomes, of which 40 were affiliated with A. hydrophila and 26 were epidemic strains. Phylogenetic analyses indicate that all ST251 strains form a coherent lineage affiliated with A. hydrophila. Within this lineage, conserved genetic loci were identified that are unique within A. hydrophila as well as genes that are present in consistently higher copy numbers than in non-epidemic A. hydrophila isolates. In addition, results from analyses of representative ST251 isolates supports that multiple lineages are present within US vAh isolated from Mississippi, whereas vAh isolated from Alabama appear clonal. This is the first report of genomic heterogeneity within US vAh isolates, with some Mississippi isolates showing closer affiliation with the Asian grass carp isolate ZC1 than with other vAh isolated in the US. To evaluate the biological significance of the identified heterogeneity, comparative disease challenges were conducted with representatives of different vAh genotypes revealing that isolate ZC1 yielded significantly lower mortality in channel catfish, relative to Alabama and Mississippi vAh isolates. Like other Asian vAh isolates, the ZC1 lineage contains all core genes for a complete type VI secretion system (T6SS. In contrast, more

  9. Classification of a Hypervirulent Aeromonas hydrophila Pathotype Responsible for Epidemic Outbreaks in Warm-Water Fishes

    Science.gov (United States)

    Rasmussen-Ivey, Cody R.; Hossain, Mohammad J.; Odom, Sara E.; Terhune, Jeffery S.; Hemstreet, William G.; Shoemaker, Craig A.; Zhang, Dunhua; Xu, De-Hai; Griffin, Matt J.; Liu, Yong-Jie; Figueras, Maria J.; Santos, Scott R.; Newton, Joseph C.; Liles, Mark R.

    2016-01-01

    Lineages of hypervirulent Aeromonas hydrophila (vAh) are the cause of persistent outbreaks of motile Aeromonas septicemia in warm-water fishes worldwide. Over the last decade, this virulent lineage of A. hydrophila has resulted in annual losses of millions of tons of farmed carp and catfish in the People's Republic of China and the United States (US). Multiple lines of evidence indicate US catfish and Asian carp isolates of A. hydrophila affiliated with sequence type 251 (ST251) share a recent common ancestor. To address the genomic context for the putative intercontinental transfer and subsequent geographic spread of this pathogen, we conducted a core genome phylogenetic analysis on 61 Aeromonas spp. genomes, of which 40 were affiliated with A. hydrophila, with 26 identified as epidemic strains. Phylogenetic analyses indicate all ST251 strains form a coherent lineage affiliated with A. hydrophila. Within this lineage, conserved genetic loci unique to A. hydrophila were identified, with some genes present in consistently higher copy numbers than in non-epidemic A. hydrophila isolates. In addition, results from analyses of representative ST251 isolates support the conclusion that multiple lineages are present within US vAh isolated from Mississippi, whereas vAh isolated from Alabama appear clonal. This is the first report of genomic heterogeneity within US vAh isolates, with some Mississippi isolates showing closer affiliation with the Asian grass carp isolate ZC1 than other vAh isolated in the US. To evaluate the biological significance of the identified heterogeneity, comparative disease challenges were conducted with representatives of different vAh genotypes. These studies revealed that isolate ZC1 yielded significantly lower mortality in channel catfish, relative to Alabama and Mississippi vAh isolates. Like other Asian vAh isolates, the ZC1 lineage contains all core genes for a complete type VI secretion system (T6SS). In contrast, more virulent US isolates

  10. Persistence, Transmission, and Virulence Characteristics of Aeromonas Strains in a Duckweed Aquaculture-Based Hospital Sewage Water Recycling Plant in Bangladesh▿

    OpenAIRE

    Rahman, Mokhlasur; Huys, Geert; Rahman, Motiur; Albert, M. John; Kühn, Inger; Möllby, Roland

    2006-01-01

    The persistence and transmission of Aeromonas in a duckweed aquaculture-based hospital sewage water treatment plant in Bangladesh was studied. A total of 670 samples from different sites of the hospital sewage water treatment plant, from feces of hospitalized children suffering from diarrhea, from environmental control ponds, and from feces of healthy humans were collected over a period of three years. In total, 1,315 presumptive Aeromonas isolates were biochemically typed by the PhenePlate r...

  11. Usefulness of Chromogenic CromoCen® AGN agar medium for the identification of the genus Aeromonas: Assessment of faecal samples.

    Science.gov (United States)

    Aguilera-Arreola, M G; Portillo-Muñoz, M I; Rodríguez-Martínez, C; Castro-Escarpulli, G

    2012-08-01

    Selective screening media for the detection and identification of Aeromonas strains are needed to guide primary isolation procedures in the clinical laboratory. This study compared the selective CromoCen® AGN chromogenic agar medium for the detection and identification of Aeromonas strains that were isolated from various samples against the conventional selective agar media that are commonly used for the isolation of this organism in food, environmental and clinical samples. The Miles and Misra and ecometric methods were used to evaluate the microbiological performance of CromoCen® AGN chromogenic agar medium, which was shown to be satisfactory. A total of 14 reference Aeromonas strains, 44 wild strains and 106 clinical stool specimens were examined using both non-chromogenic selective agars that are commonly used for Aeromonas isolation and CromoCen® AGN agar. The latter exhibited 94.73% sensitivity and 100% specificity for the various samples. On CromoCen® AGN agar medium, Aeromonas formed colonies with light green, greenish and salmon pigments with or without a surrounding wide transparent zone (halo) of 2-3mm in diameter around the entire border. This medium is recommended for the isolation and potential identification of the Aeromonas genus.

  12. 季磷盐碘对气单胞菌的抑菌杀菌效果研究%Research on Bacteriostatic and Bactericidal Efficacy of Quaternary Phosphorus Salt Iodine on Aeromonas

    Institute of Scientific and Technical Information of China (English)

    谭凤霞; 孟立霞

    2015-01-01

    以气单胞菌属标准株ATCC7966和本实验室分离的气单胞菌为试验菌株,采用营养肉汤二倍稀释法研究季磷盐碘对气单胞菌的抑菌杀菌作用.结果表明,季磷盐碘在低浓度时能抑制气单胞菌的生长增殖,高浓度杀灭细菌,其对7株气单胞菌的最小抑菌浓度(MIC)为0.156 mL/L(Aeromonas sp.T4、Aeromonas sp.T6),0.312 mL/L(ATCC7966、Aeromonas sp.T1、Aeromonas sp.T2、Aeromonas sp.T5)和0.625 mL/L(Aeromonas sp.T3),其最小杀菌浓度(MBC)为1.25 mL/L(Aeromonas sp.T2、Aeromonas sp.T4、Aeromonas sp.T6),2.5 mL/L(Aeromonas sp.T3)和5 mL/L(ATCC7966、Aeromonas sp.T1、Aeromonas sp.T5).本研究结果可为季磷盐碘的合理使用提供参考.

  13. Pancarditis in a patient with tropical pyomyositis due to Aeromonas infection

    Directory of Open Access Journals (Sweden)

    Nikhil Gupta

    2015-01-01

    Full Text Available Tropical pyomyositis is a suppurative disease of the skeletal muscles. The most common site of the infection being muscles of the thigh. Staphylococcus aureus is the most common organism isolated. Aeromonas is one of the rarest organisms described as the etiologic agent for this disease. Rarely, cardiac involvement in pyomyositis has been described in the form of myocarditis and pyopericardium. Pancarditis is a very rare event in the natural course of pyomyositis. To the best of our knowledge, there is a single case report in world literature regarding involvement of all the layers of the heart in pyomyositis. We report a case of a 30-year-old immunocompetent male who had pyomyositis and developed pancarditis, which was managed successfully with conservative management.

  14. A Report of Peritonitis from Aeromonas sobria in a Peritoneal Dialysis (PD) Patient with Necrotizing Fasciitis.

    Science.gov (United States)

    Janma, Jirayut; Linasmita, Patcharasarn; Changsirikulchai, Siribha

    2015-11-01

    A 70-years of age, male patient with underlying type 2 diabetes mellitus, hypertension, dyslipidemia and ischemic heart disease had undergone continuous ambulatory peritoneal dialysis (CAPD)for 3 years without any episodes of peritonitis. He was diagnosed with necrotizing fasciitis and later developed peritonitis after receiving a laceration from an aquatic injury suffered during the flood disaster of 2011. The blood culture, necrotic tissue and the clear dialysate collected upon admission had shown Aeromonas sobria. The route of peritonitis may be from the hematogenous spread of A. sobria resulting in necrotizing fasciitis. A. sobria should be considered as the pathogen of peritonitis in PD patients who have history of wounds from contaminated water. We suggest that the PD patients who present with septicemia and did not meet the criteria for peritonitis, the initial dialysate effluent should be sent for culture. The benefit of this is to allow early recognition and treatment of peritonitis.

  15. In Vitro Antibacterial Effect of Effective Microorganisms( EM) on Aeromonas hydrophila

    Institute of Scientific and Technical Information of China (English)

    Zhu; Zhixiu; He; Houjun; Zhang; Wenbo; Wu; Xiangdong; Wan; Gen; Deng; Shunzhou; Liu; Songlin

    2014-01-01

    In order to understand in vitro antibacterial effect of antibiotics and EM on Aeromonas hydrophila,14 isolates of A. hydrophila were isolated from diseased fish and aquaculture in the study. PCR amplification results of aerolysin gene( Aero gene) of isolates indicated that 7 out of 14 isolates were pathogenic A.hydrophila. In vitro antibacterial test indicated that 14 isolates were resistance to penicillin G,ampicillin,cephradine,cefazolin,tetracycline,terimethoprim,lincomycin and cephalexin,but showed high sensitivity to cefotaxime and furazolidone. In vitro antibacterial effect of EM on 14 isolates of A. hydrophila was positively correlated with concentration,and EM with the concentration greater than 60% had antibacterial effect on 14 isolates.

  16. Biodegradation of Reactive Black 5 by Aeromonas hydrophila strain isolated from dye-contaminated textile wastewater

    Directory of Open Access Journals (Sweden)

    Mohamed El Bouraie

    2016-09-01

    Full Text Available Aeromonas hydrophila isolate showed the best decolorization of Reactive Black 5 (RB5 at the concentration of 100 mg L−1 on modified mineral salt medium among 42 bacterial isolates. Optimization of parameters for RB5 dye decolourization was studied under static condition. Under optimized condition, decolorization efficiency of RB5 by A. hydrophila was found to be 76% at 100 mg L−1 within 24 h. The optimum pH and temperature for the decolorization was 7 and 35 °C respectively. Biodegradation and decolorization of RB5, was monitored by UV–Vis spectrophotometry, Thin Layer Chromatography, Fourier Transform Infrared Spectroscopy and Gas Chromatography Mass Spectrometry analysis. The study has confirmed the potential of A. hydrophila isolated from textile effluent in degradation of RB5 and opened scope for future analysis in the treatment of textile effluent.

  17. Production of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate) by Aeromonas hydrophila and Recombinant Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    丘远征; 刘力平; 陈国强

    2003-01-01

    Aeromonas hydrophila (A.hydrophila) 4AK4 produced poly(3-hydroxybutyrate-co-3- hydroxyhexanoate) (PHBHHx) with an almost constant 3-hydroxyhexanoate (3HHx) content of 10%-15% from lauric acid and/or soybean oil.Both A.hydrophila 4AK4 and recombinant Escherichia coli (E.coli) JMU193 (pBH32) produced PHBHHx with controllable 3HHx content when fed lauric acid and another co-substrate.With glucose or gluconate as the co-substrate, the 3HHx content in the copolyester produced by A.hydrophila 4AK4 was reduced slightly from 12% to 9%.However, the 3HHx content in the copolyester produced by E.coli JMU193 (pBH32) was significantly reduced from 9% to 2% with fructose as the co-substrate.These results show that regulation of 3HHx content in PHBHHx can be achieved using genetically engineered E.coli.

  18. Cylindrospermopsin Biodegradation Abilities of Aeromonas sp. Isolated from Rusałka Lake.

    Science.gov (United States)

    Dziga, Dariusz; Kokocinski, Mikolaj; Maksylewicz, Anna; Czaja-Prokop, Urszula; Barylski, Jakub

    2016-02-25

    The occurrence of the cyanobacterial toxin cylindrospermopsin (CYN) in freshwater reservoirs is a common phenomenon. However, the biodegradation of this toxin in environmental samples has been observed only occasionally. In this work the biodegradation ability of cylindrospermopsin was investigated based on isolates from lakes with previous cyanotoxin history. Bacterial strains were identified based on the 16S rDNA and rpoD gene comparison. CYN biodegradation was monitored using the HPLC method. The R6 strain identified as Aeromonas sp. was documented as being capable of CYN removal. This biodegradation was dependent on the pH and temperature. Additionally, the stimulation of the growth of the R6 strain in the presence of CYN was indicated. Our discovery supports the hypothesis that (in analogy to the well-known phenomenon of microcystin biodegradation) in lakes dominated by potential CYN-producing cyanobacteria, the processes of microbial utilization of this toxin may occur.

  19. Aeromonas proteolyrica bacteria in aerospace environments. [possible genetic alterations and effects on man

    Science.gov (United States)

    Foster, B. G.

    1974-01-01

    Preflight studies on Aeromonas proteolytica are reported to investigate the possibility of genetic alterations resulting in increased proteolysis in spacecraft environments. This organism may be present on human tissue and could pose medical problems if its endopeptidase and a hemolysin were to be produced in ususually high quantities or altered in such a way as to be more effective in their activities. Considered are: (1) Development of a nutrative holding medium for suspension of organisms; (2) the establishment of baseline information for the standardization of the assay for endopeptidase levels and hemolytic titers; (3) formulation of a method by which intracutaneous hemorrhage could be quantitated in guinea pig tissue; and (4) the responses of these organisms to parameters of spaceflight and experimentation.

  20. Aeromonas dhakensis pneumonia and sepsis in a neonate Risso's dolphin Grampus griseus from the Mediterranean Sea.

    Science.gov (United States)

    Pérez, Lola; Abarca, M Lourdes; Latif-Eugenín, Fadua; Beaz-Hidalgo, Roxana; Figueras, M José; Domingo, Mariano

    2015-09-17

    A neonate Risso's dolphin Grampus griseus was found stranded alive on a beach in Catalonia, Spain. Rehabilitation attempts were unsuccessful and it died 2 d later, showing pneumonia and sepsis. A pure bacterial culture was obtained from all tissues and blood and identified as Aeromonas hydrophila using the API 20NE. However, sequencing the rpoD gene showed that the strain in fact belongs to A. dhakensis, making this the first report of fatal haemorrhagic-necrotizing pneumonia and sepsis due to this species in a marine mammal. The A. dhakensis strain GMV-704 produced β-haemolysis, possessed several virulence genes and showed sensitivity to several antimicrobials. This study provides a new potential host for A. dhakensis, and its potential virulence in dolphins and its presence in the marine environment may warrant considering this species a potential threat to marine mammals.

  1. Detection and characterization of potentially pathogenic Aeromonas sobria isolated from fish Hypophthalmichthys molitrix (Cypriniformes: Cyprinidae).

    Science.gov (United States)

    Dar, Gowhar H; Dar, Shoaib A; Kamili, Azra N; Chishti, Mohammad Z; Ahmad, Fayaz

    2016-02-01

    The current study focuses on the detection and characterization of potentially pathogenic Aeromonas sobria from fish silver carp (Hypophthalmichthys molitrix). Assessment of clinical, microbiological, pathological and biochemical characteristics of A. sobria were taken into account in order to understand the epidemiology, frequency and occurrence of this infection. Clinically the infected fish (H. molitrix) was observed for various types of symptoms. A total of 33 colonies of A. sobria strain were isolated from 20 cultured H. molitrix, collected from controlled fish pond. Microscopic examination revealed that the strains were rod-shaped, Gram negative bacteria. The revealed percent probability identification of A. sobria from the biochemical characterization in VITEK system was 93% with gram negative (GN) card. The histopathology of Gills caused by this bacterium, A. sobria indicate haemorrhagic gill epithelia and epithelial hyperplasia. Lamelar epithelial hypertrophy and hyperplasia with degenerative changes of the epithelium and hypertrophic epitheliocystis infected cells on gills of H. molitrix were observed during the present study.

  2. Chemical modification of polyvinyl chloride and silicone elastomer in inhibiting adhesion of Aeromonas hydrophila.

    Science.gov (United States)

    Kregiel, Dorota; Berlowska, Joanna; Mizerska, Urszula; Fortuniak, Witold; Chojnowski, Julian; Ambroziak, Wojciech

    2013-07-01

    Disease-causing bacteria of the genus Aeromonas are able to adhere to pipe materials, colonizing the surfaces and forming biofilms in water distribution systems. The aim of our research was to study how the modification of materials used commonly in the water industry can reduce bacterial cell attachment. Polyvinyl chloride and silicone elastomer surfaces were activated and modified with reactive organo-silanes by coupling or co-crosslinking silanes with the native material. Both the native and modified surfaces were tested using the bacterial strain Aeromonas hydrophila, which was isolated from the Polish water distribution system. The surface tension of both the native and modified surfaces was measured. To determine cell viability and bacterial adhesion two methods were used, namely plate count and luminometry. Results were expressed in colony-forming units (c.f.u.) and in relative light units (RLU) per cm(2). Almost all the chemically modified surfaces exhibited higher anti-adhesive and anti-microbial properties in comparison to the native surfaces. Among the modifying agents examined, poly[dimethylsiloxane-co-(N,N-dimethyl-N-n-octylammoniopropyl chloride) methylsiloxane)] terminated with hydroxydimethylsilyl groups (20 %) in silicone elastomer gave the most desirable results. The surface tension of this modifier, was comparable to the non-polar native surface. However, almost half of this value was due to the result of polar forces. In this case, in an adhesion analysis, only 1 RLU cm(-2) and less than 1 c.f.u. cm(-2) were noted. For the native gumosil, the results were 9,375 RLU cm(-2) and 2.5 × 10(8) c.f.u. cm(-2), respectively. The antibacterial activity of active organo-silanes was associated only with the carrier surface because no antibacterial compounds were detected in liquid culture media, in concentrations that were able to inhibit cell growth.

  3. Severe sepsis caused by Aeromonas hydrophila in a patient using tocilizumab: a case report

    Directory of Open Access Journals (Sweden)

    Makino Ichiro

    2011-10-01

    Full Text Available Abstract Introduction Aeromonas species do not commonly cause disease in humans. However, when disease is seen, it often occurs in patients with underlying immunosuppression or malignancy and has a high fatality rate. Case presentation A 72-year-old Japanese woman with rheumatoid arthritis treated with tocilizumab (which has an immunosuppressive effect presented with severe epigastric pain. She had a fever with chills, hypotension and jaundice. She was diagnosed with acute suppurative cholangitis and treated with cefoperazone-sulbactam and an endoscopic drainage was performed. Jaundice was slightly improved, but the shock state and inflammatory reactions were prolonged as typical of septic shock. On the second day after admission, an electrocardiogram showed ST segment elevation and echocardiography showed ventricular wall dysfunction. Coronary arteries were patent in coronary angiography and she was diagnosed with stress-induced cardiomyopathy. Blood cultures showed Aeromonas hydrophila. A stool culture was negative for A. hydrophila. On day six, her white blood cell count and neutrophils were normalized and cefoperazone-sulbactam treatment was halted. Left ventricular function normalized on day twelve and a laparoscopic cholecystectomy for cholelithiasis was performed on the 16th day of hospitalization. A culture from the bile showed A. hydrophila. Eighteen days after surgery, tocilizumab treatment was restarted and there were no complications. Two months after restarting tocilizumab, our patient is stable without any serious events. Conclusion We present a rare case of A. hydrophila sepsis and acute suppurative cholangitis in an elderly patient with gallstones and rheumatoid arthritis using tocilizumab. This clinical course may suggest that preemptive treatment for cholelithiasis prior to using molecular-targeting agents might be feasible in elderly patients.

  4. Protection of ornamental gold fish Carassius auratus against Aeromonas hydrophila by treating Ixora coccinea active principles.

    Science.gov (United States)

    Anusha, Paulraj; Thangaviji, Vijayaragavan; Velmurugan, Subramanian; Michaelbabu, Mariavincent; Citarasu, Thavasimuthu

    2014-02-01

    Herbals such as Ixora coccinea, Daemia extensa and Tridax procumbens were selected to screen in vitro antibacterial and immunostimulant activity against the freshwater fish pathogen Aeromonas hydrophila using different organic polar and non-polar solvents. Initial screening results revealed that, ethyl acetate extracts and its purified fraction of I. coccinea was able to suppress the A. hydrophila strains at more than 15 mm of zone of inhibition and positive immunostimulant activity. The purified active fraction, which eluted from H40: EA60 mobile phase was structurally characterized by GC-MS analysis. Two compounds such as Diethyl Phthalate (1,2-Benzene dicarboxylic acid, monobutyl ester) and Dibutyl Phthalate were characterized using NIST database search. In order to study the in vivo immunostimulant influence of the compounds, the crude extracts (ICE) and purified fractions (ICF) were incorporated to the artificial diets at the concentration of 400 mg kg⁻¹ and fed to the ornamental gold fish Carassius auratus for 30 days. After termination of feeding experiment, they were challenged with highly virulent A. hydrophila AHV-1 which was isolated from infected gold fish and studied the survival, specific bacterial load reduction, serum biochemistry, haematology, immunology and histological parameters. The control diet fed fishes succumbed to death within five days at 100% mortality whereas ICE and ICF fed groups survived 60 and 80% respectively after 10 days. The diets also helped to decrease the Aeromonas load after challenge and significantly (P ≤ 0.01) improved the serum albumin, globulin and protein. The diets also helped to increase the RBC and haemoglobin level significantly (P ≤ 0.05) from the control group. Surprisingly the immunological parameters like phagocytic activity, serum bactericidal activity and lysozyme activity were significantly increased (P ≤ 0.001) in the experimental diets. Macrophages and erythrocytes were abundantly expressed in the

  5. The occurrence of Aeromonas spp. in the bottled mineral water, well water and tap water from the municipal supplies

    Directory of Open Access Journals (Sweden)

    Denise de Oliveira Scoaris

    2008-10-01

    Full Text Available The aim of this work was to study the occurrence of Aeromonas sp in the bottled mineral water, well water and tap water from the municipal supplies. Positive samples were found for Aeromonas spp. 12.7% from the mineral water, 8.3% from the artesian water and 6.5% from the tap water. The recovery of Aeromonas spp. was significantly higher in the bottled mineral and artesian water than in the tap water from municipal supplies. The occurrence of the Aeromonas spp. did not correlate significantly with the contamination indicator bacteria (i.e. total coliforms in the artesian water samples. However, a significant correlation was found between Aeromonas spp. and total coliforms in the both mineral water and tap water samples. The presence or absence of a correlation between the indicator bacteria and Aeromonas could reflect the occasional appearance of the pathogen in the drinking water and the different rates of survival and recovery of these agents compared with those fecal indicators. The finding that 41.6, 14.8 and 9.0 % of the artesian water, bottled mineral water and tap water, respectively, sampled in the current study failed to meet the Brazilian standard for total coliforms in the drinking water should therefore be of concern.A porcentagem de amostras positivas para Aeromonas foi de 12.7% para água mineral, 8.3% para água de poço artesiano e 6.5% para água do sistema público de abastecimento. O isolamento de Aeromonas spp. foi significativamente maior em água mineral e água de poço artesiano do que em água do sistema público. A ocorrência de Aeromonas spp. não teve correlação significativa com os indicadores de contaminação tradicionalmente utilizados (coliformes totais em amostras de água de poço artesiano. No entanto, esta correlação foi positiva e significativa em água mineral e água do sistema público. A presença ou ausência de correlação entre bactérias indicadoras e a presença de Aeromonas pode refletir o

  6. Aeromonas veronii N8活性菌体对Zn2+的吸附特征%Biosorption characteristic of Zn2+ by viable cells of Aeromonas veronii N8

    Institute of Scientific and Technical Information of China (English)

    柴德芳; 宋萍; 申露文; 林欣; 封磊

    2016-01-01

    Aeromonas veronii N8菌为对象,对菌体的性质及其吸附Zn2+特征进行研究.结果表明,Aeromonas veronii菌的生长周期在66 h左右,并且Zn2+对该菌的最低抑菌质量浓度为150 mg/L;N8菌体对Zn2+的吸附随时间的增加,吸附率逐渐增大,并且在90 min后达到吸附平衡.菌体的吸附率随菌体质量浓度的增加而变大,并随Zn2+质量浓度的增加而变小.吸附前、后扫描电镜及能谱分析(scanning electron microscope-energy dispersive X-ray,SEM-EDX)的表征结果显示,在菌体的细胞壁表面检测到Zn元素,说明Aeromonas veronii N8菌体对Zn2+具有一定的吸附作用.菌体的Zn2+吸附过程可采用Toth模型进行描述.

  7. Molecular Phylogenetics and Temporal Diversification in the Genus Aeromonas Based on the Sequences of Five Housekeeping Genes

    Science.gov (United States)

    Lorén, J. Gaspar; Farfán, Maribel; Fusté, M. Carmen

    2014-01-01

    Several approaches have been developed to estimate both the relative and absolute rates of speciation and extinction within clades based on molecular phylogenetic reconstructions of evolutionary relationships, according to an underlying model of diversification. However, the macroevolutionary models established for eukaryotes have scarcely been used with prokaryotes. We have investigated the rate and pattern of cladogenesis in the genus Aeromonas (γ-Proteobacteria, Proteobacteria, Bacteria) using the sequences of five housekeeping genes and an uncorrelated relaxed-clock approach. To our knowledge, until now this analysis has never been applied to all the species described in a bacterial genus and thus opens up the possibility of establishing models of speciation from sequence data commonly used in phylogenetic studies of prokaryotes. Our results suggest that the genus Aeromonas began to diverge between 248 and 266 million years ago, exhibiting a constant divergence rate through the Phanerozoic, which could be described as a pure birth process. PMID:24586399

  8. Skrining Fitokimia Metabolit Sekunder Dalam Daun Binahong (Anredera cordifolia (Ten) Steenis) Untuk Uji In Vitro Daya Hambat Pertumbuhan Aeromonas Hydrophila

    OpenAIRE

    Ginting, Prita Yulianti Anasta

    2016-01-01

    Binahong leaves are one of natural product to be used to treat the disease of living organisme due to having secondary metabolite to show antibacterial activity. The purpose of this research was to study secondary metabolite of Binahong leaves of which showing antibacterial, to analysis effectivity of antibacterial Binahong leaves extract to inhibit growth of bacteria Aeromonas hydrophila. An experimental laboratory with six treatments and three replications for in vitro was tested. A pap...

  9. Use of Aeromonas spp. as general indicators of antimicrobial susceptibility among bacteria in aquatic environments in Thailand

    Directory of Open Access Journals (Sweden)

    Masaru eUsui

    2016-05-01

    Full Text Available Antimicrobials are widely used, not only for treating human infections, but also for treatment of livestock and in fish farms. Human habitats in Southeastern Asian countries are located in close proximity to aquatic environments. As such, the human populations within these regions are at risk of exposure to antimicrobial resistant bacteria (ARB, and thereby disseminating antimicrobial resistance genes (ARGs. In this study, we collected water samples from 15 sites (5 sites in Chao Phraya River, 2 sites at the mouth of Chao Phraya River, 3 sites in Ta Chin River, and 5 sites at city canals and 12 sites (6 sites at city canals, 2 sites at chicken farms, 2 sites at pig farms, and 2 samples from sites at pig farms that were subsequently treated at a biogas plant in Thailand in 2013 and 2014, respectively. In total, 117 Aeromonas spp. were isolated from the water samples, and these organisms exhibited various antimicrobial susceptibility profiles. Moreover, there was a significant correlation between the environmental concentration of tetracyclines and the rates of tetracycline resistance in the isolated Aeromonas spp. Notably, however, the concentration and resistance rates of tetracycline in samples derived from pig farms were higher than those of samples harvested from other aquatic environments. These findings suggest that the high concentrations of antimicrobials observed in these aquatic environments likely select for ARGs. Furthermore, they indicate that Aeromonas spp. comprise an effective marker for monitoring antimicrobial resistance in aquatic environments.

  10. Use of Aeromonas spp. as General Indicators of Antimicrobial Susceptibility among Bacteria in Aquatic Environments in Thailand.

    Science.gov (United States)

    Usui, Masaru; Tagaki, Chie; Fukuda, Akira; Okubo, Torahiko; Boonla, Chanchai; Suzuki, Satoru; Seki, Kanako; Takada, Hideshige; Tamura, Yutaka

    2016-01-01

    Antimicrobials are widely used, not only for treating human infections, but also for treatment of livestock and in fish farms. Human habitats in Southeastern Asian countries are located in close proximity to aquatic environments. As such, the human populations within these regions are at risk of exposure to antimicrobial resistant bacteria, and thereby disseminating antimicrobial resistance genes (ARGs). In this study, we collected water samples from 15 sites (5 sites in Chao Phraya River, 2 sites at the mouth of Chao Phraya River, 3 sites in Ta Chin River, and 5 sites at city canals) and 12 sites (6 sites at city canals; 2 sites at chicken farms; 2 sites at pig farms; and 2 samples from sites at pig farms, which were subsequently treated at a biogas plant) in Thailand in 2013 and 2014, respectively. In total, 117 Aeromonas spp. were isolated from the water samples, and these organisms exhibited various antimicrobial susceptibility profiles. Notably, there was a significant correlation between the environmental concentration of tetracyclines and the rates of tetracycline resistance in the isolated Aeromonas spp.; however, both the concentration and rates of tetracycline resistance in samples derived from pig farms were higher than those of samples harvested from other aquatic environments. These findings suggest that the high concentrations of antimicrobials observed in these aquatic environments likely select for ARGs. Furthermore, they indicate that Aeromonas spp. comprise an effective marker for monitoring antimicrobial resistance in aquatic environments.

  11. Identification of antibiotic resistance cassettes in class 1 integrons in Aeromonas spp. strains isolated from fresh fish (Cyprinus carpio L.).

    Science.gov (United States)

    Sarria-Guzmán, Yohanna; López-Ramírez, María Patricia; Chávez-Romero, Yosef; Ruiz-Romero, Erick; Dendooven, Luc; Bello-López, Juan Manuel

    2014-05-01

    Forty-six Aeromonas spp. strains were isolated from fresh fish and investigated for their antimicrobial susceptibility, detection of Class 1 integrons by PCR, and arrangement of gene cassettes. Selected isolates were further characterized by enterobacterial repetitive intergenic consensus-PCR. Twenty isolates were found to carry Class 1 integrons. Amplification of the variable regions of the integrons revealed diverse bands ranging in size from 150 to 1,958 pb. Sequence analysis of the variable regions revealed the presence of several gene cassettes, such as adenylyl transferases (aadA2 and aadA5), dihydrofolate reductases (dfrA17 and dfrA1), chloramphenicol acetyl transferase (catB3), β-lactamase (oxa2), lincosamide nucleotidil transferase (linF), aminoglycoside-modifying enzyme (apha15), and oxacillinase (bla OXA-10). Two open reading frames with an unknown function were identified as orfC and orfD. The aadA2 cassette was the most common integron found in this study. Interestingly, five integrons were detected in the plasmids that might be involved in the transfer of resistance genes to other bacteria. This is a first report of cassette encoding for lincosamides (linF) resistance in Aeromonas spp. Implications on the incidence of integrons in isolates of Aeromonas spp. from fresh fish for human consumption, and its possible consequences to human health are discussed.

  12. Detection and distribution of putative virulence associated genes in Aeromonas species from freshwater and wastewater treatment plant.

    Science.gov (United States)

    Igbinosa, Isoken H; Okoh, Anthony I

    2013-11-01

    The detection of genes responsible for Aeromonas virulence is a vital tool in establishing the potential pathogenicity of the bacteria, as these virulence genes may act alone or in synergy in the establishment of infections. Freshwater and wastewater mixed liquor samples were collected from Kat river and Fort Beaufort wastewater treatment plant in the Eastern Cape Province of South Africa. Polymerase chain reaction was utilized for the amplification of the different genes coding for virulence. All virulence associated genes screened (alt, lip, fla, aer, ast, hlyA) were detected in at least one Aeromonas isolates. In fresh water sample, virulence genes were distributed as follows: lip (67%), aer (43%), alt (33%), fla (62%), ast (10%), and hlyA (86%), while in wastewater samples the occurrence were as follows: lip (92%), aer (21%), alt (54%), fla (83%), ast (29%), and hlyA (88%). The presence of these virulence genes in environmental Aeromonas isolates is of concern to public health as these organisms are potential pathogens in the environment and the virulence determinants could be transferred to aquatic organisms and humans by one mechanism or the other.

  13. 气单胞菌(Aeromonas sp.D-4)降解LAS的研究

    Institute of Scientific and Technical Information of China (English)

    李峤; 邓家齐; 王德铭

    1988-01-01

    Aeromonas sp.D-4不能以LAS作为唯一碳源,它对LAS的利用是通过共代谢来完成的。LAS对D-4具有毒害作用,而且,起始LAS浓度越高,毒害作用越大。LAS的最大去除串与起始LAS浓度呈负相关。当起始LAS在40-120mg/L之间时,去除串较高;如果起始LAS在40mg/L左右,则去除率可达s096以上。研究还表明,Aeromonas sp.D-4纯培养对LAS的去除率(最大值84.97%)大于混合菌(最大值78.57%)。耗氧呼吸测定证实了Aeromonas sp.D-4对于LAS的共代谢和LAS对细菌的毒性,同时也证实了培养基中LAS的消失是细菌作用的结果。

  14. Research Progress on Aeromonas hydrophila%嗜水气单胞菌的研究进展

    Institute of Scientific and Technical Information of China (English)

    姜艳丽; 李丽丽

    2015-01-01

    为有效预防嗜水气单胞菌引起传染病的发生,以减少对人畜的损害,通过回顾嗜水气单胞菌的分类地位(嗜温性和运动性的气单胞菌属的模式菌)、生物学性质,对其主要毒力因子(外毒素及胞外蛋白酶)和鉴定技术(生化鉴定、免疫血清技术和分子生物学技术)的研究成果进行了综述。%In order to prevent the infectious dieases caused by Aeromonas hydrophila ,and reduce the damage to human and animals ,the taxonomic status and biological character of Aeromonas hydrophila were reviewed ,the research of virulence factor (exotoxin and extracellular protease)and identification of Aeromonas hydrophila were summarized ,in cluding biochenrical identification ,immune serum and molecular biology techniques .

  15. Determination of microbial diversity of Aeromonas strains on the basis of multilocus sequence typing, phenotype, and presence of putative virulence genes.

    Science.gov (United States)

    Martino, Maria Elena; Fasolato, Luca; Montemurro, Filomena; Rosteghin, Marina; Manfrin, Amedeo; Patarnello, Tomaso; Novelli, Enrico; Cardazzo, Barbara

    2011-07-01

    The genus Aeromonas has been described as comprising several species associated with the aquatic environment, which represents their principal reservoir. Aeromonas spp. are commonly isolated from diseased and healthy fish, but the involvement of such bacteria in human infection and gastroenteritis has frequently been reported. The primary challenge in establishing an unequivocal link between the Aeromonas genus and pathogenesis in humans is the extremely complicated taxonomy. With the aim of clarifying taxonomic relationships among the strains and phenotypes, a multilocus sequencing approach was developed and applied to characterize 23 type and reference strains of Aeromonas spp. and a collection of 77 field strains isolated from fish, crustaceans, and mollusks. All strains were also screened for putative determinants of virulence by PCR (ast, ahh1, act, asa1, eno, ascV, and aexT) and the production of acylated homoserine lactones (AHLs). In addition, the phenotypic fingerprinting obtained from 29 biochemical tests was submitted to the nonparametric combination (NPC) test methodology to define the statistical differences among the identified genetic clusters. Multilocus sequence typing (MLST) achieved precise strain genotyping, and the phylogenetic analysis of concatenated sequences delineated the relationship among the taxa belonging to the genus Aeromonas, providing a powerful tool for outbreak traceability, host range diffusion, and ecological studies. The NPC test showed the feasibility of phenotypic differentiation among the majority of the MLST clusters by using a selection of tests or the entire biochemical fingerprinting. A Web-based MLST sequence database (http://pubmlst.org/aeromonas) specific for the Aeromonas genus was developed and implemented with all the results.

  16. Ultraviolet radiation as disinfection for fish surgical tools

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Ricardo W.; Markillie, Lye Meng; Colotelo, Alison HA; Geist, David R.; Gay, Marybeth E.; Woodley, Christa M.; Eppard, M. B.; Brown, Richard S.

    2013-04-04

    Telemetry is frequently used to examine the behavior of fish, and the transmitters used are normally surgically implanted into the coelomic cavity of fish. Implantation requires the use of surgical tools such as scalpels, forceps, needle holders, and sutures. When fish are implanted consecutively, as in large telemetry studies, it is common for surgical tools to be sterilized or, at minimum, disinfected between each use so that pathogens that may be present are not spread among fish. To determine the efficacy for this application, ultraviolet (UV) radiation was used to disinfect surgical tools exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. These organisms included Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica, causative agents of furunculosis, coldwater disease, bacterial kidney disease, and saprolegniasis (water mold), respectively. Four experiments were conducted to address the question of UV efficacy. In the first experiment, forceps were exposed to the three bacteria at three varying concentrations. After exposure to the bacterial culture, tools were placed into a mobile Millipore UV sterilization apparatus. The tools were then exposed for three different time periods – 2, 5, or 15 min. UV radiation exposures at all durations were effective at killing all three bacteria on forceps at the highest bacteria concentrations. In the second experiment, stab scalpels, sutures, and needle holders were exposed to A. salmonicida using the same methodology as used in Experiment 1. UV radiation exposure at 5 and 15 min was effective at killing A. salmonicida on stab scalpels and sutures but not needle holders. In the third experiment, S. parasitica, a water mold, was tested using an agar plate method and forceps-pinch method. UV radiation was effective at killing the water mold at all three exposure durations. Collectively, this study shows that UV

  17. Regulation of the cytotoxic enterotoxin gene in Aeromonas hydrophila: characterization of an iron uptake regulator.

    Science.gov (United States)

    Sha, J; Lu, M; Chopra, A K

    2001-10-01

    The cytotoxic enterotoxin Act from a diarrheal isolate, SSU, of Aeromonas hydrophila is aerolysin related and crucial to the pathogenesis of Aeromonas infections. To elucidate the role of environmental signals which influence the expression of the cytotoxic enterotoxin gene (act), a portion of the act gene, including the putative promoter region, was fused in frame to a truncated alkaline phosphatase gene (phoA) of Escherichia coli. The act::phoA reporter gene was then introduced into the chromosome of A. hydrophila by using the suicide vector pJQ200SK, allowing the fusion protein to be secreted out into the culture medium. Western blot analysis demonstrated the presence of a correctly size 110-kDa fusion protein in the culture supernatant, which reacted with both anti-Act and anti-alkaline phosphatase antibodies. Based on alkaline phosphatase (PhoA) activity in the culture supernatant, we demonstrated that calcium significantly increased the activity of the act promoter but that glucose and iron repressed its activity in a dose-dependent fashion. The act promoter exhibited optimal activity at pH 7.0 and at 37 degrees C, and maximal PhoA activity was noted when the culture was aerated. Using a Vibrio cholerae iron uptake regulator gene (fur) as a probe, a 2.6-kb SalI/HindIII DNA fragment from an A. hydrophila chromosome was cloned and sequenced. The DNA sequence revealed a 429-bp open reading frame that exhibited 69% homology at the DNA level with the fur gene and 79% homology at the amino acid level with the iron uptake regulator (Fur) protein of V. cholerae. Complementation experiments demonstrated that the A. hydrophila fur gene could restore iron regulation in an E. coli fur-minus mutant. Using the suicide vector pDMS197, we generated a fur isogenic mutant of wild-type A. hydrophila SSU. Northern blot analysis data indicated that the repression in the transcription of the act gene by iron was relieved in the fur isogenic mutant. Further, iron regulation in the

  18. Adhesion, invasion, intracellular survival and cytotoxic activity of strains of Aeromonas spp. in HEp-2, Caco-2 and T-84 cell lines.

    Science.gov (United States)

    dos Santos, Paula Azevedo; Pereira, Ana Claudia Machado; Ferreira, Andréa Fonseca; de Mattos Alves, Maria Angélica; Rosa, Ana Cláudia Paula; Freitas-Almeida, Angela Corrêa

    2015-05-01

    The genus Aeromonas contains important pathogen for both humans and other animals, being responsible for the etiology of intestinal and extraintestinal diseases. The pathology caused by these bacteria involves several virulence factors, such as the ability to produce toxins, adhesion and invasion. The properties conferred by these factors have been extensively studied in experiments of interaction between bacterial strains and cell culture. We evaluate the interaction of eight Aeromonas spp. strains, previously isolated from human faeces, food and water with HEp-2, Caco-2 and T-84 cell lines. Cytotoxic effects, the pattern of adhesion, invasive capacity and intracellular survival were analyzed. The results showed that Aeromonas strains were adherent to three cells lines in 6 h of incubation, displaying the aggregative adherence pattern. Among eight strains studied, 50% produced cytotoxic effects on HEp-2 cells, while none of the strains produced cytotoxic effects on Caco-2 and T-84 cells at 48 h. This study demonstrated that subsets of Aeromonas isolated from different sources were able to invade intestinal (T-84, Caco-2) and epithelial (HEp-2) cell lines cultivated in vitro surviving in intracellular environments up to 72 h. Finally, our results support the pathogenic potential of Aeromonas, especially those of food and clinical sources.

  19. First record of the rare species Aeromonas schubertii from mussels: phenotypic and genetic reevaluation of the species and a review of the literature.

    Science.gov (United States)

    Latif-Eugenín, Fadua; Beaz-Hidalgo, Roxana; Figueras, María José

    2016-05-01

    In a study where the prevalence of Aeromonas in shellfish was analysed, three isolates of Aeromonas schubertii were identified, representing this the first report of this species from mussels. This species was originally described in 1988 from strains isolated from extra-intestinal human infections and since then has been cited in only 18 occasions. For many years, A. schubertii was the only mannitol-negative species of the genus. However, three additional mannitol-negative species (Aeromonas simiae, Aeromonas diversa and Aeromonas australiensis) have been described. This, together with the fact that A. schubertii is a rare human pathogenic species, motivated the present study to characterize its biochemical behaviour and differentiation from the other mannitol-negative species. The molecular similarity (16S rRNA, rpoD and gyrB genes) of the strains, presence of virulence genes and antimicrobial resistance were determined. All A. schubertii strains showed the same phenotypic behaviour, i.e. they use citrate, are positive for lysine decarboxylase and DL-lactate, but negative for production of mannitol, indole and acid from sucrose and could be easily differentiated from other mannitol-negative species. All strains carried the aerA and lafA virulence genes and showed susceptibility to all antibiotics tested. Seafood could be a transmission route of this bacterium to humans.

  20. Novel application of Mahua (Madhuca sp.) flowers for augmented protease production from Aeromonas sp. S1.

    Science.gov (United States)

    Bhattacharya, Amrik; Saini, Vandana; Gupta, Anshu

    2012-10-01

    The present study explored the utilization of Mahua (Madhuca sp.) flowers, a major non-timber forest product (NTFP) of India, as a low-cost, natural substrate for protease production under submerged fermentation. Bacterial strain Aeromonas sp. Si1, previously reported by us, was used as the protease producer. Using Mahua flower extract (MFE) as the medium additive, the protease production could successfully be enhanced by 5.6-fold (564.5 UmL-1) after 24 h of fermentation under optimized conditions compared with initial production of 99.9 UmL' in the absence of MFE. The cultural parameters for optimum production of protease were determined to be: incubation time-24 h; pH-7.0; MFE concentration-5% (v/v); inoculum size-0.3% (v/v) and agitation rate-200 rpm. The results obtained demonstrate the potential of cheaper and abundantly available Mahua flowers for induction of proteases, and thus offer a new approach for value addition to this biomass through industrial enzyme production.

  1. Effect of Plasma Processing and Organosilane Modifications of Polyethylene on Aeromonas hydrophila Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Dorota Kregiel

    2014-01-01

    Full Text Available The aim of our research was to study how the modifications of polyethylene—a material commonly used in medicine and water industry—influence bacterial cell attachment and biofilm formation. The native surface was activated and modified using two-step process consisting in the activation of native surface with a H2O vapor plasma followed by its treatment with various organosilanes, namely, [3(tertbutylamine-2hydroxy propyloxypropyl] diethoxymethylsilane, 1H,1H,2H,2H-perfluorooctylmethyldimethoxysilane, dimethoxydimethylsilane, and isobutylmethyldimethoxysilane. The effect of polyethylene modification after chemical treatment was analyzed using surface tension measurement. The adhesive properties of Aeromonas hydrophila LOCK0968 were studied in water with a low concentration of organic compounds, using luminometric and microscopic methods, and the viability of the adhered bacterial cells was evaluated using the colony forming units method. After two-week incubation the chemically modified materials exhibited better antiadhesive and antibacterial characteristics in comparison to the native surface. Among the examined modifying agents, dimethoxydimethylsilane showed the best desired properties.

  2. Cloning, sequencing and expression of the gene encoding the extracellular metalloprotease of Aeromonas caviae.

    Science.gov (United States)

    Kawakami, K; Toma, C; Honma, Y

    2000-01-01

    A gene (apk) encoding the extracellular protease of Aeromonas caviae Ae6 has been cloned and sequenced. For cloning the gene, the DNA genomic library was screened using skim milk LB agar. One clone harboring plasmid pKK3 was selected for sequencing. Nucleotide sequencing of the 3.5 kb region of pKK3 revealed a single open reading frame (ORF) of 1,785 bp encoding 595 amino acids. The deduced polypeptide contained a putative 16-amino acid signal peptide followed by a large propeptide. The N-terminal amino acid sequence of purified recombinant protein (APK) was consistent with the DNA sequence. This result suggested a mature protein of 412 amino acids with a molecular mass of 44 kDa. However, the molecular mass of purified recombinant APK revealed 34 kDa by SDS-PAGE, suggesting that further processing at the C-terminal region took place. The 2 motifs of zinc binding sites deduced are highly conserved in the APK as well as in other zinc metalloproteases including Vibrio proteolyticus neutral protease, Emp V from Vibrio vulnificus, HA/P from Vibrio cholerae, and Pseudomonas aeruginosa elastase. Proteolytic activity was inhibited by EDTA, Zincov, 1,10-phenanthroline and tetraethylenepentamine while unaffected by the other inhibitors tested. The protease showed maximum activity at pH 7.0 and was inactivated by heating at 80 C for 15 min. These results together suggest that APK belongs to the thermolysin family of metalloendopeptidases.

  3. Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution (0.85%, w/v). Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection (dpi) for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase (SOD) activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.

  4. Inactivation of Pseudomonas aeruginosa and Aeromonas hydrophila by silver in tap water.

    Science.gov (United States)

    Silvestry-Rodriguez, Nadia; Bright, Kelly R; Uhlmann, Donald R; Slack, Donald C; Gerba, Charles P

    2007-09-01

    This study was conducted to assess the efficacy of silver as a secondary disinfectant to replace or reduce the level of chlorine utilized in water distribution systems. Pseudomonas aeruginosa and Aeromonas hydrophila are opportunistic pathogens present in drinking water and have been associated with waterborne disease. After 8 hours of exposure to 100 microg/L of silver, there was a >6-log10 reduction in P. aeruginosa in tap water at room temperature at pH7 and a 5.55-log10 reduction in the presence of 3 mg/L humic acid. Similar reductions were observed at pH9. At 4 degrees C, reductions greater than 4-log10 were observed after 24 hours. For A. hydrophila, a >6-log10 reduction occurred at both pH7 and pH9 within nine hours. The World Health Organization has determined that this amount of silver could be used for water disinfection without health risks. Furthermore, silver shows promise as a secondary disinfectant, even in the presence of organic matter in concentrations that would reduce the effectiveness of free chlorine.

  5. Reduction of Aeromonas hidrophyla biofilm on stainless stell surface by essential oils

    Directory of Open Access Journals (Sweden)

    Alessandra Farias Millezi

    2013-01-01

    Full Text Available This study demonstrates the possibility of using sanitizing detergents based on natural products for the elimination and/or reduction of Aeromonas hydrophila biofilm formed on stainless steel surfaces. The goal of this work was to determine the reduction effect of sanitizing detergents containing essential oils of Thymus vulgaris (thyme and Cymbopogon citratus (lemongrass on biofilm formed by A. hydrophila on AISI 304 stainless steel coupons, using UHT skimmed milk as substratum. There was adhesion and biofilm formation by A. hydrophila at 28 ºC, presenting 7.60 log cfu.cm-2 after the fourth day of cultivation. There was no significant difference between the lemongrass treatment and that of the thyme oil (p 0.05. The treatment with lemongrass solution reduced the biofilm by 4.51 log cfu cm-2 at 25 ºC. The thyme detergent also reduced the number of cfu cm-2 by 3.84 log cycles at 25 ºC. The use of the lemongrass and thyme solutions efficiently reduced the A. hydrophila biofilm.

  6. The LBP Gene and Its Association with Resistance to Aeromonas hydrophila in Tilapia

    Directory of Open Access Journals (Sweden)

    Gui Hong Fu

    2014-12-01

    Full Text Available Resistance to pathogens is important for the sustainability and profitability of food fish production. In immune-related genes, the lipopolysaccharide-binding protein (LBP gene is an important mediator of the inflammatory reaction. We analyzed the cDNA and genomic structure of the LBP gene in tilapia. The full-length cDNA (1901 bp of the gene contained a 1416 bp open reading frame, encoding 471 amino acid residues. Its genomic sequence was 5577 bp, comprising 15 exons and 14 introns. Under normal conditions, the gene was constitutively expressed in all examined tissues. The highest expression was detected in intestine and kidney. We examined the responses of the gene to challenges with two bacterial pathogens Streptcoccus agalactiae and Aeromonas hydrophila. The gene was significantly upregulated in kidney and spleen post-infection with S. agalactiae and A. hydrophila, respectively. However, the expression profiles of the gene after the challenge with the two pathogens were different. Furthermore, we identified three SNPs in the gene. There were significant associations (p < 0.05 of two of the three SNPs with the resistance to A. hydrophila, but not with the resistance to S. agalactiae or growth performance. These results suggest that the LBP gene is involved in the acute-phase immunologic response to the bacterial infections, and the responses to the two bacterial pathogens are different. The two SNPs associated with the resistance to A. hydrophila may be useful in the selection of tilapia resistant to A. hydrophila.

  7. Production and efficacy of an Aeromonas hydrophila recombinant S-layer protein vaccine for fish.

    Science.gov (United States)

    Poobalane, Saravanane; Thompson, Kim D; Ardó, László; Verjan, Noel; Han, Hyun-Ja; Jeney, Galina; Hirono, Ikuo; Aoki, Takashi; Adams, Alexandra

    2010-04-30

    A recombinant protein for the S-layer protein of Aeromonas hydrophila was produced and its ability to protect common carp Cyprinus carpio L. against six virulent isolates of A. hydrophila was assessed. A group of 120 carp (30-40 g) were vaccinated intra-peritoneally with 0.1 ml of adjuvanted vaccine (30 microg protein per fish). Another group of 120 carp were injected with 0.1 ml of PBS-adjuvant mixture to serve as controls. Twenty fish from each group were challenged with each one of six virulent isolates of A. hydrophila 35 days post-vaccination. The fish were maintained in 12 separate tanks before terminating the experiment at 16 days post-challenge. The relative percentage survival (RPS) for the six isolates of A. hydrophila ranged from 56 to 87%. The difference in survival rate of fish challenged with four of the isolates was statistically significant in vaccinated fish compared to control fish, when analysed using a Chi-square test. The results of the study suggest that the recombinant S-layer protein of A. hydrophila could be useful as a vaccine antigen to protect fish against different isolates of this pathogenic bacterium.

  8. Detection of multidrug resistance Aeromonas hydrophila in farm raised fresh water prawns

    Directory of Open Access Journals (Sweden)

    Md. Bakhtiar Lijon

    2015-12-01

    Full Text Available This study was undertaken for isolation, identification and determination of antibiogram profile of Aeromonas hydrophila in farm raised fresh water prawn (Macrobrachium rosenbergii on five commercial ghers. Fresh water prawns (n=25 were collected from five ghers located at Satkhira, Bagerhat and Khulna districts of Bangladesh. Brain (n=25, muscle (n=25 and intestine (n=25 samples were collected aseptically from fresh water prawn and inoculated into alkaline peptone (APW water for enrichment at 37℃ for 8 h. Enriched cultured was streaked into Thiosulfate Citrate Bile Salt Sucrose (TCBS agar to isolate bacteria. Bacteria were identified by cultural, Gram staining, biochemical properties and polymerase chain reaction (PCR assay. The antibiogram profiles of bacteria were investigated against 5 commonly used antibiotics (Gentamicin, Cefalexin, Ampicillin, Azithromycin and Ciprofloxacin by disc diffusion method. Thirteen A. hydrophila isolates were identified and the prevalence of the A. hydrophila in fresh water prawn was 17.33%. All 13 (100% isolates were sensitive to Ciprofloxacin, Gentamicin, Azithromycin and resistant to Ampicillin and Cefalexin. The results of this study indicate that farm raised fresh water prawn harbor multidrug resistant A. hydrophila which might causes public health problem if enter into human food chain.

  9. Effect of plasma processing and organosilane modifications of polyethylene on Aeromonas hydrophila biofilm formation.

    Science.gov (United States)

    Kregiel, Dorota; Niedzielska, Kamila

    2014-01-01

    The aim of our research was to study how the modifications of polyethylene--a material commonly used in medicine and water industry--influence bacterial cell attachment and biofilm formation. The native surface was activated and modified using two-step process consisting in the activation of native surface with a H2O vapor plasma followed by its treatment with various organosilanes, namely, [3(tertbutylamine-2hydroxy) propyloxypropyl] diethoxymethylsilane, 1H,1H,2H,2H-perfluorooctylmethyldimethoxysilane, dimethoxydimethylsilane, and isobutylmethyldimethoxysilane. The effect of polyethylene modification after chemical treatment was analyzed using surface tension measurement. The adhesive properties of Aeromonas hydrophila LOCK0968 were studied in water with a low concentration of organic compounds, using luminometric and microscopic methods, and the viability of the adhered bacterial cells was evaluated using the colony forming units method. After two-week incubation the chemically modified materials exhibited better antiadhesive and antibacterial characteristics in comparison to the native surface. Among the examined modifying agents, dimethoxydimethylsilane showed the best desired properties.

  10. Isolation and characterization of Aeromonas schubertii from diseased snakehead, Channa maculata (Lacepède).

    Science.gov (United States)

    Chen, Y F; Liang, R S; Zhuo, X L; Wu, X T; Zou, J X

    2012-06-01

    Pure bacterial cultures were isolated from diseased snakeheads, Channa maculata (Lacepède), suffering high mortality in a farm in Zhongshan, southern China. Three isolates, namely ZS20100725, ZS20100725-1 and ZS20100725-2, were identified as Aeromonas schubertii. All the isolates showed high 16S rRNA sequence similarities with A. schubertii. The isolates exhibited strong virulence to snakeheads in experimental challenges with LD(50) ranging between 1.4 × 10(4) and 6.4 × 10(6) CFU g(-1). Two of the isolates were positive for haemolysin, elastase, lipase and lecithinase by phenotypic determination, which was further confirmed by PCR amplification of the haemolysin and elastase genes. In sterile liquid medium, the best growth conditions of strain ZS20100725 were 30 °C, pH 7 and 0.5% salinity (w/v). Antibiotic susceptibility tests showed that strain ZS20100725 was susceptible to cefoxitin, cefoperazone and chloramphenicol. Furthermore, histopathology of diseased snakeheads infected with A. schubertii showed necrosis and congestion in liver, kidney and spleen and also damage to the cardiac muscle, intestine and gills.

  11. Antibacterial activities of bioactive compounds extracted from Marine algae Gracilaria salicornia against Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Somayeh Rasooli

    2015-04-01

    Full Text Available Herbal medicinal products have attracted significant research interest in recent years. Considering the efficiency of algae products in controlling pathogenic bacteria and also easy access to large resources of algae, this study was conducted to evaluate the effects of methanolic, chloroformic and aqueous extracts of Gracilaria salicornia against Aeromonas hydrophila, a heterotrophic, Gram-negative, rod-shaped bacterium found mainly in warm climate. Algae samples were collected from Qeshm Island coastlines and transferred to the laboratory. Standard methods were used to obtain the algae extract. Antibacterial activities of various extracts were tested against the bacterium using well diffusion assay method. Significant differences were observed in antibacterial activities of different extracts (P<0.05. The diameter of zone of growth inhibition varied in correlation with concentration of the extracts (50, 100, 200 and 300 mg.ml-1. The best inhibition zone was observed at 100, 200 and 300 mg.ml-1 methanolic and 300 mg.ml-1 aqueous extracts.

  12. The LBP gene and its association with resistance to Aeromonas hydrophila in tilapia.

    Science.gov (United States)

    Fu, Gui Hong; Liu, Feng; Xia, Jun Hong; Yue, Gen Hua

    2014-12-01

    Resistance to pathogens is important for the sustainability and profitability of food fish production. In immune-related genes, the lipopolysaccharide-binding protein (LBP) gene is an important mediator of the inflammatory reaction. We analyzed the cDNA and genomic structure of the LBP gene in tilapia. The full-length cDNA (1901 bp) of the gene contained a 1416 bp open reading frame, encoding 471 amino acid residues. Its genomic sequence was 5577 bp, comprising 15 exons and 14 introns. Under normal conditions, the gene was constitutively expressed in all examined tissues. The highest expression was detected in intestine and kidney. We examined the responses of the gene to challenges with two bacterial pathogens Streptcoccus agalactiae and Aeromonas hydrophila. The gene was significantly upregulated in kidney and spleen post-infection with S. agalactiae and A. hydrophila, respectively. However, the expression profiles of the gene after the challenge with the two pathogens were different. Furthermore, we identified three SNPs in the gene. There were significant associations (p tilapia resistant to A. hydrophila.

  13. Characterization of Aeromonas trota strains that cross-react with Vibrio cholerae O139 Bengal.

    Science.gov (United States)

    Albert, M J; Ansaruzzaman, M; Shimada, T; Rahman, A; Bhuiyan, N A; Nahar, S; Qadri, F; Islam, M S

    1995-12-01

    It has previously been shown that Vibrio cholerae O139 Bengal shares antigens with V. cholerae serogroups O22 and O155. We detected six surface water isolates of Aeromonas trota that agglutinated in polyclonal antisera to V. cholerae O139 and V. cholerae O22 but not in antiserum to V. cholerae O155. On the basis of agglutinin-absorption studies, the antigenic relationship between the cross-reacting bacteria were found to be in an a,b-a,c fashion, where a is the common antigenic epitope and b and c are unique epitopes. The antigen sharing between A. trota strains and V. cholerae O139 was confirmed in immunoblot studies. However, A. trota strains did not react with two monoclonal antibodies specific for V. cholerae O139 and, consequently, tested negative in the Bengal SMART rapid diagnostic test for V. cholerae O139 which uses one of the monoclonal antibodies. A polyclonal antiserum to a cross-reacting A. trota strain cross-protected infant mice against cholera on challenge with virulent V. cholerae O139. All A. trota strains were cytotoxic for HeLa cells, positive for adherence to HEp-2 cells, and weakly invasive for HEp-2 cells; one strain was heat-stable toxin positive in the suckling mouse assay; however, all strains were negative for cholera toxin-like enterotoxin. Studies on bacteria that share somatic antigen with V. cholerae O139 may shed further light on the genesis of V. cholerae O139.

  14. Anti-biofouling property of vanillin on Aeromonas hydrophila initial biofilm on various membrane surfaces.

    Science.gov (United States)

    Ponnusamy, K; Kappachery, S; Thekeettle, M; Song, J H; Kweon, J H

    2013-09-01

    Biofouling is a serious problem on filter membranes of water purification systems due to formation of bacterial biofilms, which can be detrimental to the membrane performance. Biofouling occurs on membrane surface and therefore greatly influences the physical and chemical aspects of the surface. Several membranes including microfiltration, ultrafiltration, and reverse osmosis (RO) membranes were used to learn about the anti-biofouling properties of vanillin affecting the membrane performances. Vanillin has been recognized as a potential quorum quenching compound for Aeromonas hydrophila biofilms. The initial attachment and dynamics of biofilm growth were monitored using scanning electron microscopy and confocal laser scanning microscopy. Biofilm quantities were measured using a plate count method and total protein determinations. Vanillin addition was effective in the prevention of biofilm formation on the tested membrane surfaces. Among the membranes, RO membranes made with cellulose acetate showed the most substantial reduction of biofilm formation by addition of vanillin. The biofilm reduction was confirmed by the results of surface coverage, biomass and protein accumulation. The HPLC spectrum of the spent culture with vanillin addition showed that vanillin may interfere with quorum sensing molecules and thus prevent the formation of the biofilms.

  15. Proteomic Analysis Reveals That Metabolic Flows Affect the Susceptibility of Aeromonas hydrophila to Antibiotics

    Science.gov (United States)

    Yao, Zujie; Li, Wanxin; Lin, Yi; Wu, Qian; Yu, Feifei; Lin, Wenxiong; Lin, Xiangmin

    2016-01-01

    The overuse of antibiotics results in the development of antibiotic resistance and limits the useful life of these drugs in fighting bacteria, including Aeromonas hydrophila, a well-known opportunistic pathogen that causes serious infections in fish and other animals. In this study, we investigated the adaptive resistance mechanism in A. hydrophila by multiple proteomic methods. Dimethyl labeling and label-free methods were performed to compare the differential expression of proteins in response to various doses of oxytetracycline (OXY). The results point to the conclusions that, in response to OXY stress, translational processes increase the abundance of these proteins whereas largely central metabolic pathways decrease their abundance. To confirm our hypothesis, various exogenous metabolites were compounded with OXY, and the resulting survival capabilities were measured. Results show that 7 metabolites (malic acid, serine, methionine, etc.) significantly decreased the survival capabilities of A. hydrophila in the presence of OXY, whereas 4 metabolites (arginine, lysine, tyrosine, etc.) did the opposite. Further investigation suggests that a compound comprising exogenous metabolites in combination with various antibiotics could have a significant bactericidal effect and might come into widespread use, especially together with tetracycline antibiotics. These findings may provide new clues to the antimicrobial treatment of A. hydrophila infection. PMID:27991550

  16. Structural Insights on PHA Binding Protein PhaP from Aeromonas hydrophila

    Science.gov (United States)

    Zhao, Hongyu; Wei, Hui; Liu, Xi; Yao, Zhenyu; Xu, Manyu; Wei, Daixu; Wang, Jiawei; Wang, Xinquan; Chen, Guo-Qiang

    2016-01-01

    Phasins or PhaPs are a group of amphiphilic proteins that are found attached to the surface of microbial polyhydroxyalkanoate (PHA) granules. They have both structural and regulatory functions and can affect intracellular PHA accumulation and mediate protein folding. The molecular basis for the diverse functions of the PhaPs has not been fully understood due to the lack of the structural knowledge. Here we report the structural and biochemical studies of the PhaP cloned from Aeromonas hydrophila (PhaPAh), which is utilized in protein and tissue engineering. The crystal structure of PhaPAh was revealed to be a tetramer with 8 α-helices adopting a coiled-coil structure. Each monomer has a hydrophobic and a hydrophilic surface, rendering the surfactant properties of the PhaPAh monomer. Based on the crystal structure, we predicted three key amino acid residues and obtained mutants with enhanced stability and improved emulsification properties. The first PhaP crystal structure, as reported in this study, is an important step towards a mechanistic understanding of how PHA is formed in vivo and why PhaP has such unique surfactant properties. At the same time, it will facilitate the study of other PhaP members that may have significant biotechnological potential as bio-surfactants and amphipathic coatings. PMID:28009010

  17. An experimental vaccine against Aeromonas hydrophila can induce protection in rainbow trout, Oncorhynchus mykiss (Walbaum)

    Science.gov (United States)

    LaPatra, S.E.; Plant, K.P.; Alcorn, S.; Ostland, V.; Winton, J.

    2010-01-01

    A candidate vaccine against Aeromonas hydrophila in rainbow trout, Oncorhynchus mykiss, was developed using a bacterial lysate. To test the strength of protection, A. hydrophila challenge models were compared using injection into both the intraperitoneal (IP) cavity and the dorsal sinus (DS) with selected doses of live bacteria washed in saline or left untreated. Unlike the IP route, injection into the DS with either saline washed or unwashed cells resulted in consistent cumulative mortality and a dose response that could be used to establish a standard challenge having an LD50 of approximately 3 × 107 colony forming units per fish. Survivors of the challenge suffered significantly lower mortality upon re-challenge than naïve fish, suggesting a high level of acquired resistance was elicited by infection. Passive immunization using serum from hyper-immunized fish also resulted in significantly reduced mortality indicating protection can be transferred and that some portion of resistance may be antibody mediated. Vaccination of groups of rainbow trout with A. hydrophila lysate resulted in significant protection against a high challenge dose but only when injected along with Freund’s complete adjuvant. At a low challenge dose, mortality in all groups was low, but the bacterial lysate alone appeared to offer some protection.

  18. Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

    Science.gov (United States)

    Zhang, Junjie; Zou, Wenzheng; Yan, Qingpi

    2008-08-01

    Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution (0.85%, w/v). Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection (dpi) for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase (SOD) activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.

  19. Antimicrobial Susceptibility and Characterization of Outer Membrane Proteins of Aeromonas hydrophila Isolated in China

    Institute of Scientific and Technical Information of China (English)

    GUO Peng; WANG Na; LIU Yong-jie; LU Cheng-ping

    2014-01-01

    Aeromonas hydrophila isolates from clinical cases (n=43) were tested against 8 antimicrobial agents and typed by outer membrane protein (OMP) pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin (MICs, 16 mg mL-1) and sulfamonomethoxine (MICs, 64 mg mL-1), but susceptible to norlfoxacin (MICs, 0.5 mg mL-1). There was a high incidence of resistance to erythromycin (90.70%) and tylosin (93.02%), while a low incidences of resistance to ciprofloxacin (2.33%), enrofloxacin (2.33%) and florfenicol (4.65%). Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective proifles. The strains with the similar OMP proifles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to lforfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to lforfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to lfuoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.

  20. Inhibition of Aeromonas sobria serine protease (ASP) by α2-macroglobulin.

    Science.gov (United States)

    Murakami, Yoji; Wada, Yoshihiro; Kobayashi, Hidetomo; Irie, Atsushi; Hasegawa, Makoto; Yamanaka, Hiroyasu; Okamoto, Keinosuke; Eto, Masatoshi; Imamura, Takahisa

    2012-10-01

    ASP is a serine protease secreted by Aeromonas sobria. ASP cleaves various plasma proteins, which is associated with onset of sepsis complications, such as shock and blood coagulation disorder. To investigate a host defense mechanism against this virulence factor, we examined the plasma for ASP inhibitor(s). Human plasma inhibited ASP activity for azocasein, which was almost completely abolished by treating plasma with methylamine, which inactivates α2-macroglobulin (α2-MG). The ASP-inhibitor complex in ASP-added plasma was not detected by immunoblotting using anti-ASP antibody; however, using gel filtration of the plasma ASP activity for an oligopeptide, the ASP substrate was eluted in the void fraction (Mw>200 000), suggesting ASP trapping by α2-MG. Indeed, human α2-MG inhibited ASP azocaseinolytic activity in a dose-dependent manner, rapidly forming a complex with the ASP. Fibrinogen degradation by ASP was completely inhibited in the presence of α2-MG. α1-Protease inhibitor, antithrombin, and α2-plasmin inhibitor neither inhibited ASP activity nor formed a complex with ASP. Surprisingly, ASP degraded these plasma serine protease inhibitors. Thus, α2-MG is the major ASP inhibitor in the human plasma and can limit ASP virulence activities in A. sobria infection sites. However, as shown by fluorescence correlation spectroscopy, slow ASP inhibition by α2-MG in plasma may indicate insufficient ASP control in vivo.

  1. Surface protein composition of Aeromonas hydrophila strains virulent for fish: identification of a surface array protein

    Energy Technology Data Exchange (ETDEWEB)

    Dooley, J.S.G.; Trust, T.J.

    1988-02-01

    The surface protein composition of members of a serogroup of Aeromonas hydrophila was examined. Immunoblotting with antiserum raised against formalinized whole cells of A. hydrophila TF7 showed a 52K S-layer protein to be the major surface protein antigen, and impermeant Sulfo-NHS-Biotin cell surface labeling showed that the 52K S-layer protein was the only protein accessible to the Sulfo-NHS-Biotin label and effectively masked underlying outer membrane (OM) proteins. In its native surface conformation the 52K S-layer protein was only weakly reactive with a lactoperoxidase /sup 125/I surface iodination procedure. A UV-induced rough lipopolysaccharide (LPS) mutant of TF7 was found to produce an intact S layer, but a deep rough LPS mutant was unable to maintain an array on the cell surface and excreted the S-layer protein into the growth medium, indicating that a minimum LPS oligosaccharide size required for A. hydrophila S-layer anchoring. The native S layer was permeable to /sup 125/I in the lactoperoxidase radiolabeling procedure, and two major OM proteins of molecular weights 30,000 and 48,000 were iodinated. The 48K species was a peptidoglycan-associated, transmembrane protein which exhibited heat-modifiable SDS solubilization behavior characteristic of a porin protein. A 50K major peptidoglycan-associated OM protein which was not radiolabeled exhibited similar SDS heat modification characteristics and possibly represents a second porin protein.

  2. Aeromonas hydrophila-associated skin lesions and septicaemia in a Nile crocodile (Crocodylus niloticus : clinical communication

    Directory of Open Access Journals (Sweden)

    H. Turutoglu

    2005-06-01

    Full Text Available Aeromonas hydrophila is one of the most common bacteria associated with the aquatic environment. There are , however, limited data on A. hydrophila infection in crocodilians. The aim of this report is to describe a case of skin lesions and septicaemia associated with A. hydrophila in a Nile crocodile (Crocodylus niloticus. A captive male crocodile in the Zoological Park of Antalya (Turkey was found dead without showing signs of any disease. Gross examination showed brown or red-spotted skin lesions of varying size. These lesions were mostly scattered over the abdomen and occasionally on the tail and feet. At necropsy, numerous white, multifocal and randomly distributed areas were seen on the liver. Gram-stained smears from skin and liver lesions showed Gram-negative bacilli arranged in clusters. Pure cultures of A. hydrophila were recovered from skin, internal organs and blood. Isolates were found to be susceptible to ceftiofur, amoxicillin + clavulanic acid, oxytetracycline, enrofloxacin, danofloxacin, neomycin, gentamicin, and lincomycin + neomycin. A pathogenicity test was performed using this isolate on 4 male 2-year-old New Zealand white rabbits. Local abscesses formed in 2 rabbits injected subcutaneously and the 2 that were injected intraperitoneally died as a result of septicaemia. In conclusion, this report has shown that A. hydrophila may cause skin lesions and even death due to septicaemia in crocodiles.

  3. PROBIOTIK Bacillus firmus UNTUK PENGENDALIAN PENYAKIT Aeromonas hydrophila PADA BUDIDAYA IKAN LELE DUMBO, Clarias gariepinus

    Directory of Open Access Journals (Sweden)

    Angela Mariana Lusiastuti

    2013-08-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui efektivitas pemberian bakteri probiotik Bacillus firmus terhadap ketahanan benih ikan lele dumbo (Clarias gariepinus yang diinfeksi Aeromonas hydrophila. Probiotik diberikan melalui media budidaya dengan Rancangan Acak Lengkap (RAL menggunakan lima perlakuan dan tiga ulangan yang diaplikasikan untuk pengendalian penyakit motile aromonas septicemia (MAS. Perlakuan tersebut adalah A (tanpa penambahan bakteri probiotik B. firmus (sebagai control, B (penambahan bakteri probiotik B. firmus 105 cfu/mL, C (penambahan bakteri probiotik B. firmus 107 cfu/mL, D (penambahan bakteri probiotik B. firmus 109 cfu/mL, dan E (penambahan bakteri probiotik B. firmus 1011 cfu/mL. Pengamatan meliputi tingkat sintasan ikan uji setelah diuji tantang dengan A. hydrophila, indeks fagositik, diferensial leukosit dan kualitas air. Analisis data tingkat sintasan dilakukan dengan menggunakan uji F dengan taraf signifikansi 5%. Indeks fagositik, differensial leukosit dan kualitas air dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa sintasan tertinggi setelah diinfeksi A. hydrophila terdapat pada perlakuan D (109 cfu/mL yaitu 53,33% dan adanya peningkatan kadar limfosit sebesar 81% serta aktivitas fagosit sebesar 60% setelah penambahan bakteri probiotik B. firmus. Sementara hasil terendah terdapat pada perlakuan A (kontrol (tanpa penambahan bakteri probiotik sebesar 8,33%, aktivitas fagosit sebesar 60% setelah pemeliharaan ikan uji selama 14 hari.

  4. Two membrane filter media (mADA/0129 and mSA/0129 agars) for enumeration of motile Aeromonas in seawater.

    Science.gov (United States)

    Alonso, J L; Garay, E

    1989-10-01

    Sewage-contaminated natural seawater was analysed for the presence of motile Aeromonas by two membrane filtration procedures. Incubation of membranes on two modified media (mADA (0/129) and mSA (0/129) were compared. The specificity of the two media was high, 95.8% on mADA (0/129) and 94.8% on mSA (0129). The most frequent species identified were A. caviae, followed by A. hydrophila and A. sobria. Motile Aeromonas counts were high in both media (greater than 10(4)/100 ml) and no significant differences were observed between them. The two membrane filtration procedures allowed rapid quantitative recovery of motile Aeromonas from seawater in the presence of very large numbers of competing microflora.

  5. Diverse Profiles of N-acyl Homoserine L-Lactones, Biofilm, Virulence Genes and Integrons in Food-Borne Aeromonas Isolates.

    Science.gov (United States)

    Nagar, Vandan; Sinha, Vibha; Bandekar, Jayant R

    2015-08-01

    Aeromonas are regarded as opportunistic as well as primary pathogens of humans and fish, and are associated with gastroenteritis and septicemia in humans. Production of N-acyl-homoserine lactone (AHL) signal molecules and biofilm was determined in 22 Aeromonas isolates, from different food products in India, using thin-layer chromatography (TLC) analysis and microtiter-plate assay, respectively. Overall, highly heterogeneous patterns of AHL production were observed, with the production of N-butanoyl homoserine lactone (C4-HSL) and N-hexanoyl homoserine lactone (C6-HSL) by the majority (81.8%) of Aeromonas food isolates. Moreover, putative N-pentanoyl homoserine lactone (C5-HSL), N-heptanoyl homoserine lactone (C7-HSL), and N-octanoyl homoserine lactone (C8-HSL) were produced by 72.7%, 27.3%, and 9.1% of isolates, respectively. This is the 1st report of production of C7-HSL by Aeromonas species. Aeromonas food isolates were highly variable in their biofilm forming abilities with majority of them as weak biofilm producers in 2 different media, TSB and M9 minimal medium supplemented with 0.4% glucose. The genes encoding for putative virulence factors, glycerophospholipid cholesterol acyltransferase (gcat), heat-labile cytotonic enterotoxin (alt), heat-stable cytotonic enterotoxin (ast), serine protease (ser), polar flagella (fla), and lateral flagella (lafA) were present in 95.5%, 59.1%, 22.7%, 81.8%, 77.3%, and 22.7% of the strains, respectively. Class 1 integrons (100 to 3000 bp) were found in 68.2% of food isolates; whereas, 50% isolates contained class 2 integrons (150 to 1600 bp). This study provides a baseline data on the diversity of AHLs, biofilm forming ability and presence of virulence genes and integrons in Aeromonas food isolates from India.

  6. Aeromonas spp. and microbial indicators in raw drinking water source Aeromonas sp. e indicadores microbiológicos em fontes de água não tratada

    Directory of Open Access Journals (Sweden)

    Marisa Di Bari

    2007-09-01

    Full Text Available Aeromonas species are autochtonous in the aquatic environment and some of them have been associated with health effects like wound infections, septicemia and diarrhoeal illness. In this study, the occurrence of Aeromonas spp. and microbial indicators in raw drinking water from wells, springs, fountains and mineral waters was evaluated. A total of 126 water samples was analyzed for Aeromonas spp. by the membrane filtration technique using ADA media and by P/A test. Typical colonies of Aeromonas spp. were submitted to biochemical tests for species differentiation. Toxin production was tested using Y-1 mouse adrenal cells. Coliforms and heterotrophic bacteria were enumerated by membrane filtration and pour plate techniques, respectively. P. aeruginosa, C. perfringens and fecal streptococci were determined by P/A method. Aeromonas spp. were isolated in 36.5% of the samples, whereas total and thermotolerant coliforms were detected in 51.2% and in 23.8% of the samples, respectively. C. perfringens, fecal streptococci and P. aeruginosa were present in 16.5%, 20.4% and 3.8% of the samples, respectively. The concentrations of heterotrophic bacteria were higher than 1,0x10³ CFU/mL in 52.5% of the samples. A. hydrophila was the most frequent species, followed by A. allosaccharophila,A. jandaei,A.sobria and HG2. A heat label toxin was detected in 13 from the 58 strains tested. These data show that the drinking water sources analyzed can represent a risk for human health. It is important to consider that wells and springs are used as drinking water supply in poor areas and rural regions, where undernourished people more susceptible to infections by these microorganisms predominate.Bactérias do gênero Aeromonas são naturais no ambiente aquático e algumas espécies podem causar infecções em humanos como feridas, septicemia e diarréia. Este trabalho objetivou avaliar a ocorrência de Aeromonas sp. em 126 amostras de água de poços, nascentes, fontes e

  7. Aeromonas hydrophila infection in Estuarine crocodile from Thailand%泰国湾鳄嗜水气单胞菌感染

    Institute of Scientific and Technical Information of China (English)

    李明杰; 王志国

    2003-01-01

    @@ 气单胞菌属(Aeromonas)中嗜水气单胞菌(Aeromonas hy-drophila)是两栖爬行动物中最常见的机会致病菌.嗜水气单胞菌在水体环境中广泛分布,能使水生动物、水禽发病.现在越来越多的报道表明,嗜水气单胞菌亦能感染东北虎、北极熊、猪、兔等哺乳动物及人类.

  8. Melanization and pathogenicity in the insect, Tenebrio molitor, and the crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3.

    Directory of Open Access Journals (Sweden)

    Chadanat Noonin

    Full Text Available Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS, bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish and Tenebrio molitor larvae (mealworm. The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the

  9. Thin-film fixed-bed reactor for solar photocatalytic inactivation of Aeromonas hydrophila: influence of water quality

    Science.gov (United States)

    2012-01-01

    Background Controlling fish disease is one of the major concerns in contemporary aquaculture. The use of antibiotics or chemical disinfection cannot provide a healthy aquaculture system without residual effects. Water quality is also important in determining the success or failure of fish production. Several solar photocatalytic reactors have been used to treat drinking water or waste water without leaving chemical residues. This study has investigated the impact of several key aspects of water quality on the inactivation of the pathogenic bacterium Aeromonas hydrophila using a pilot-scale thin-film fixed-bed reactor (TFFBR) system. Results The level of inactivation of Aeromonas hydrophila ATCC 35654 was determined using a TFFBR with a photocatalytic area of 0.47 m2 under the influence of various water quality variables (pH, conductivity, turbidity and colour) under high solar irradiance conditions (980–1100 W m-2), at a flow rate of 4.8 L h-1 through the reactor. Bacterial enumeration were obtained through conventional plate count using trypticase soy agar media, cultured in conventional aerobic conditions to detect healthy cells and under ROS-neutralised conditions to detect both healthy and sub-lethally injured (oxygen-sensitive) cells. The results showed that turbidity has a major influence on solar photocatalytic inactivation of A. hydrophila. Humic acids appear to decrease TiO2 effectiveness under full sunlight and reduce microbial inactivation. pH in the range 7–9 and salinity both have no major effect on the extent of photoinactivation or sub-lethal injury. Conclusions This study demonstrates the effectiveness of the TFFBR in the inactivation of Aeromonas hydrophila under the influence of several water quality variables at high solar irradiance, providing an opportunity for the application of solar photocatalysis in aquaculture systems, as long as turbidity remains low. PMID:23194331

  10. Characterization and virulence potential of phenotypically diverse Aeromonas veronii isolates recovered from moribund freshwater ornamental fishes of Kerala, India.

    Science.gov (United States)

    Sreedharan, Krishnan; Philip, Rosamma; Singh, Isaac Sarojani Bright

    2013-01-01

    In the present study, we investigated the involvement of Aeromonas spp. in eliciting disease outbreaks in freshwater ornamental fishes across the state of Kerala, India. We investigated three incidences of disease, in which the moribund fishes exhibited clinical signs such as haemorrhagic septicemia (in gouramy, Trichogaster sp.), dropsy (in Oscar, Astronotus ocellatus) and tail rot/fin rot (in gold fish, Carassius carassius). Pure cultures (n = 20 from each fish; 60 in total) of Aeromonas spp. were recovered from the abdominal fluid as well as from internal organs of affected fishes, although they could not be identified to species level because of the variations in their phenotypic characters. The molecular fingerprinting of the isolates using Enterobacterial Repetitive Intergenic Consensus PCR proved the genetic diversity of the isolates from the three sites. The phylogenetic trees constructed using concatenated sequences (using 16S rRNA, gyrA, gyrB and rpoD genes) indicated that they were related to Aeromonas veronii. They exhibited marked cytotoxic and haemolytic activity, which were responsible for the pathogenic potential of the isolates. The isolates possessed multiple virulence genes such as enterotoxins (act and alt), haemolytic toxins (aerA and hlyA), genes involved in type III secretion system (ascV, aexT and ascF-ascG), glycerophospholipid-cholesterol acyltransferase (gcat) and a type IV pilus (tapA) gene, as determined by PCR. Virulence of representative isolates to goldfish was also tested, and we found LD(50) values of 10(4.07)-10(5.35) cfu/fish. Furthermore, the organisms could be recovered as pure cultures from the lesions as well as from the internal organs.

  11. Melanization and pathogenicity in the insect, Tenebrio molitor, and the crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3.

    Science.gov (United States)

    Noonin, Chadanat; Jiravanichpaisal, Pikul; Söderhäll, Irene; Merino, Susana; Tomás, Juan M; Söderhäll, Kenneth

    2010-12-29

    Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS), bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish) and Tenebrio molitor larvae (mealworm). The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core) is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT) containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the proPO system

  12. Resistencia a antibioticos y presencia de plasmidos en: Aeromonas hydrophila, Vibrio fluvialis y Vibrio furnissii, aislados de Carassius auratus auratus

    OpenAIRE

    Pilar Negrete Redondo; Jorge Romero Jarero; José Luis Arredondo Figueroa

    2004-01-01

    Se aislaron e identificaron 70 cepas bacterianas del riñón de peces de ornato Carassius auratus con signos y lesiones de infección. Las especies bacterianas aisladas e identificadas, Aeromonas hydrophila, Vibrio fluvialis y Vibrio furnissii, han sido descritas como causantes de diarrea en humano y como patógeno muy agresivo en cultivos de Ciprinus carpio. Por esta razón se ha hecho mal uso y abuso de antibióticos para evitar y controlar la presencia de esta bacteria en los cultivos. El uso fu...

  13. Determinación de factores de virulencia en cepas de Aeromonas spp., aisladas a partir de pescado

    OpenAIRE

    William Suárez Q.; Fanny Herrera A.

    2012-01-01

    RESUMENObjetivo. Investigar la incidencia de cinco marcadores fenotípicos de virulencia en cepas de Aeromonas aisladas a partir de muestras de pescado expendido en Pamplona, Colombia. Materiales y métodos. Se utilizaron 47 cepas identificadas previamente. Se evaluaron: actividad hemolítica en agar sangre, suplementado con 5% de eritrocitos de cordero y agar sangre suplementado con 5% eritrocitos de sangre humana; actividad proteolítica en agar Mueller-Hinton suplementado al 10% (p/v) con lech...

  14. An Aeromonas caviae Genomic Island Is Required for both O-Antigen Lipopolysaccharide Biosynthesis and Flagellin Glycosylation ▿

    OpenAIRE

    Tabei, S. Mohammed B.; Hitchen, Paul G.; Day-Williams, Michaela J.; Merino, Susana; Vart, Richard; Pang, Poh-Choo; Horsburgh, Gavin J.; Viches, Silvia; Wilhelms, Markus; Tomás, Juan M.; Dell, Anne; Shaw, Jonathan G

    2009-01-01

    Aeromonas caviae Sch3N possesses a small genomic island that is involved in both flagellin glycosylation and lipopolysaccharide (LPS) O-antigen biosynthesis. This island appears to have been laterally acquired as it is flanked by insertion element-like sequences and has a much lower G+C content than the average aeromonad G+C content. Most of the gene products encoded by the island are orthologues of proteins that have been shown to be involved in pseudaminic acid biosynthesis and flagellin gl...

  15. Effect of electron irradiation and packaging atmosphere on the survival of aeromonas hydrophila in minced poultry meat

    Science.gov (United States)

    Stecchini, M. L.; Sarais, I.; Del Torre, M.; Fuochi, P. G.

    1995-02-01

    Resistance to electron irradiation of Aeromonas hydrophila inoculated in minced poultry meat packed in presence of air or under vacuum was examined. Surviving bacteria were counted on starch ampicillin agar containing 100 μg/ml of ampicillin. Radiation resistance, expressed as D 10 values, was calculated from the survival curves and found to be 0.12 and 0.12 kGy in poultry meat packed in air or under vacuum respectively. Storage at 2°C of meat samples irradiated at 0.5 kGy further reduced the number of A. hydrophila.

  16. PARTICIPACION DEL COMPLEJO PIRUVATO DESHIDROGENASA DE AEROMONAS CAVIAE ST EN RESISTENCIA TELURITO DE POSTASIO (K2TEO3)

    OpenAIRE

    2008-01-01

    El telurito de potasio (K2TeO3) es altamente tóxico para la mayoría de los seres vivos. Aunque se desconoce el mecanismo de toxicidad especifico, recientemente se ha demostrado que estaría dado, al menos en parte, por el establecimiento de un estrés oxidativo. Aeromonas caviae ST, el microorganismo utilizado en este estudio es altamente resistente a K2TeO3 y extractos crudos de esta bacteria catalizan la reducción de K2TeO3 in vitro. Se obtuvo fracciones con actividad telurito reductasa qu...

  17. Biochemical characteristics, serogroups, and virulence factors of aeromonas species isolated from cases of diarrhoea and domestic water samples in Chennai

    Directory of Open Access Journals (Sweden)

    Alavandi S

    2003-01-01

    Full Text Available PURPOSE: The objective of the present study was to delineate the differences between the clinical and environmental Aeromonas species with respect to their biochemical characteristics, serogrouping and virulence factors, in order to find a phenotypic marker of enteropathogenicity. METHODS: A total of 55 Aeromonas spp. inclusive of 19 isolates from cases of diarrhoea, and 36 from water samples comprising, 10 isolates of A. hydrophila, 21 isolates each of A. sobria, and A. caviae, two isolates of A. jandaei and one isolate of A. veronii were subjected to analysis of their biochemical characteristics, serogrouping, and virulence factors. RESULTS: Among the differences recorded in the biochemical characteristics in the three major species, the most striking characteristic was fermentation of lactose, which was observed in all the 11 A. caviae isolates recovered from water samples. None of the 10 clinical isolates of A. caviae tested fermented lactose. The clinical Aeromonas isolates belonged to seven typable serogroups, O:13, O:14, O:16, O:21, O:27, O:32 and O:35. The environmental isolates belonged to eight different serogroups, such as, O:3, O:11, O:14, O:16, O:18, O:28, O:64 and O:78 and were predominated by serotypes O:18 and O:64. Among the virulence factors tested, 89% of the environmental isolates produced b haemolysin, while only 62.3% of clinical isolates were able to do so. There was no significant difference between the clinical and environmental aeromonads with respect to their enterotoxigenicity in suckling mice in vivo, cytotoxicity in vitro in Vero cell monolayers, and ability to produce siderophores. CONCLUSION: Efforts to delineate the differences between the clinical and environmental Aeromonas spp. did not reveal significant difference between them. However, difference was observed with respect to their ability to produce b haemolysin, wherein, higher percentage of environmental isolates was haemolytic. The results also suggest

  18. DIARRHEA OUTBREAK IN PERNAMBUCO, BRAZIL, ASSOCIATED WITH A HEAT-STABLE CYTOTOXIC ENTEROTOXIN PRODUCED BY Aeromonas caviae.

    Science.gov (United States)

    Lopes, Ana Carolina Amaral; Martins, Luciano Moura; Gatti, Maria Silvia Viccari; Falavina Dos Reis, Cristhiane Moura; Hofer, Ernesto; Yano, Tomomasa

    2015-01-01

    In the present study enterotoxic and cytotoxic activities of twenty Aeromonas caviae strains were examined. They originated from fecal specimens of patients with acute diarrhea during an outbreak in Brazil in 2004. Culture supernatants of fourteen strains (70%) caused fluid accumulation in rabbit ileal intestinal loops and in suckling mice assays, and also showed a cytotoxic activity in Vero and Caco-2 cells. The enterotoxic and cytotoxic factors were heat-stable after culture supernatants treatment at 100 ºC. The results revealed that A. caviae strains produce a putative diarrheagenic virulence factor, a heat-stable cytotoxic enterotoxin that could be linked to the diarrhea outbreak that took place in Brazil.

  19. Biological approach to synthesize TiO2 nanoparticles using Aeromonas hydrophila and its antibacterial activity

    Science.gov (United States)

    Jayaseelan, Chidambaram; Rahuman, Abdul Abdul; Roopan, Selvaraj Mohana; Kirthi, Arivarasan Vishnu; Venkatesan, Jayachandran; Kim, Se-Kwon; Iyappan, Moorthy; Siva, Chinnadurai

    2013-04-01

    Nanosized materials have been an important subject in basic and applied sciences. A novel, low-cost, green and reproducible bacteria, Aeromonas hydrophila mediated biosynthesis of titanium dioxide nanoparticles (TiO2 NPs) was reported. The resulting nanoparticles were characterized by FTIR, XRD, AFM and FESEM with EDX. FTIR showed characteristic bands (1643 and 3430 cm-1) finds the role of carboxyl group Osbnd H stretching amine Nsbnd H stretch in the formation of TiO2 NPs. The XRD spectrum confirmed that the synthesized TiO2 NPs were in the form of nanocrystals, as evidenced by the peaks at 2θ values of 27.47°, 31.77°, 36.11°, 41.25°, 54.39°, 56.64° and 69.54° were identified as 110, 100, 101, 111, 211, 220 and 301 reflections, respectively. The crystallite sizes were calculated using Scherrer's formula applied to the major intense peaks and found to be the size of 40.50 nm. The morphological characterization was analyzed by FESEM and the analysis showed the NPs smooth shaped, spherical and uneven. GC-MS analysis showed the main compounds found in A. hydrophila were uric acid (2.95%), glycyl-L-glutamic acid (6.90%), glycyl-L-proline (74.41%) and l-Leucyl-d-leucine (15.74%). The potential glycyl-L-proline could have played an important role as a capping agent. A possible mechanism for the biosynthesis of TiO2 NPs has been proposed. The antibacterial activity of the synthesized TiO2 NPs was assessed by well diffusion method toward A. hydrophila, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis and showed effective inhibitory activity against S. aureus (33 mm) and S. pyogenes (31 mm).

  20. Immunostimulatory effect of artificial feed supplemented with indigenous plants on Clarias gariepinus against Aeromonas hydrophila.

    Science.gov (United States)

    Verma, Vipin Kumar; Rani, Kumari Vandana; Sehgal, Neeta; Prakash, Om

    2013-12-01

    The antibacterial activity of methanol extracts of Ficus benghalensis (prop-root) and Leucaena leucocephala (pod seed) was evaluated by measurement of zone of inhibition against pathogenic bacteria, Escherichia coli and Aeromonas hydrophila. Control artificial feed and artificial feed supplemented with 5% powder of F. benghalensis and L. leucocephala were prepared. Juvenile Clarias gariepinus were divided into four groups, acclimatized to laboratory conditions and fed with respective feeds for 20 days prior to the experiment. Immunomodulatory response of supplementary feed was studied by challenging the fish intraperitoneally at weekly intervals, with A. hydrophila. One set of fish, not challenged with A. hydrophila was used as a negative control, to analyze any detrimental effect of supplementary feed, while positive control, comprised of challenged fish fed with non-supplemented feed. Other two groups of fish were challenged with A. hydrophila and fed with respective supplementary feeds. Blood was collected on weekly intervals for four weeks and serum samples were analyzed to evaluate the damage of fish by A. hydrophila through liver function tests. The increase in the levels of Serum glutamic oxaloacetic transaminase (SGOT) and Serum Glutamic pyruvate transaminase (SGPT) in positive control group indicated the damage of liver & kidney. However the levels did not change significantly in fish fed with supplementary feeds when compared to negative control group. Nitric oxide, SOD, ALP and lipid peroxidase indicated lower stress levels in these fish compared to positive control. Fish fed with supplementary feed showed increased lysozyme activity and phagocytic index indicating an increase in non-specific immune response. The immunoglobulin levels of in serum were analyzed by homologous sandwich ELISA, which showed higher antibody production in fish fed with supplementary feed. The current study suggests conclusively, immunostimulatory role of F. benghalensis (prop