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Sample records for aeromonas veronii plasmid

  1. Small Protein B upregulates sensor kinase bvgS expression in Aeromonas veronii

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    Zhu eLiu

    2015-06-01

    Full Text Available Earlier studies reveal that Small Protein B (SmpB, a class of well-conserved tmRNA-binding proteins, is essential for the trans-translation process, which functions as a system for translation surveillance and ribosome rescue. Here, we report a previously unrecognized mechanism by which SmpB alone positively regulates the expression of a sensor kinase, BvgS, in Aeromonas veronii. A reporter plasmid was constructed in which the promoter of bvgS was used to control the expression of the enhanced green fluorescent protein (eGFP gene. When the reporter plasmid was co-transformed with a SmpB expression construct into E. coli, the relative fluorescence intensity increased about 3-fold. Transformation with a truncated form of smpB gene showed that the C-terminus had little effect, while N-terminus unexpectedly increased eGFP production. Next, a series of SmpB mutants were generated by site-directed mutagenesis. When the mutants SmpB (G11S or SmpB (E32AG was used in the experiment, eGFP expression dropped significantly compared with that of wild type SmpB. Further,purified SmpB was shown to bind the promoter regions of bvgS in the agarose gel retardation assay. Quantitative RT-PCR analysis showed that eGFP transcript levels increased approximately 25-fold in the presence of SmpB. Likewise, bvgS transcripts decreased significantly in smpB knockout A. veronii. Similar to BvgS inhibition, smpB knockout in A. veronii displayed a reduced capability in salt tolerance. Collectively, the data presented here will facilitate a deeper understanding of SmpB-mediated regulatory circuits as a transcriptional factor in A. veronii.

  2. Characterization of pathogenic Aeromonas veronii bv. veronii associated with ulcerative syndrome from Chinese longsnout catfish (Leiocassis longirostris Günther

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    Shuang-Hu Cai

    2012-03-01

    Full Text Available 273 bacterial strains were isolated from 20 Chinese longsnout catfish samples. The biochemical characteristics of all strains conformed to the species description of Aeromonas veronii bv. veronii on the basis of Vitek GNI+ card. Furthermore, 16S rDNA, gyrB and rpoD sequences of the representative strain PY50 were sequenced and showed high similarity with A. veronii bv. veronii in Genbank. Antibiotic-resistance of the representative strain PY50 was assessed by the Kirby-Bauer disk diffusion method, and the results showed it was susceptible and moderately susceptible to 13 and 4 of the 21 antimicrobial agents tested. Extracellular products of strain PY50 contained gelatinase, lecithinase, elastase, most of lipase and lipopolysaccharide. Virulence of strain PY50 and extracellular products to Chinese longsnout catfish were also tested, and LD50 were about 3.47×10(4 CFU per fish and 11.22 μg per fish in intraperitoneal injection respectively. This is the first report that A. veronii bv. veronii was the pathogenic agent of ulcerative syndrome in Chinese longsnout catfish.

  3. Pan-genome analysis of Aeromonas hydrophila, Aeromonas veronii and Aeromonas caviae indicates phylogenomic diversity and greater pathogenic potential for Aeromonas hydrophila.

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    Ghatak, Sandeep; Blom, Jochen; Das, Samir; Sanjukta, Rajkumari; Puro, Kekungu; Mawlong, Michael; Shakuntala, Ingudam; Sen, Arnab; Goesmann, Alexander; Kumar, Ashok; Ngachan, S V

    2016-07-01

    Aeromonas species are important pathogens of fishes and aquatic animals capable of infecting humans and other animals via food. Due to the paucity of pan-genomic studies on aeromonads, the present study was undertaken to analyse the pan-genome of three clinically important Aeromonas species (A. hydrophila, A. veronii, A. caviae). Results of pan-genome analysis revealed an open pan-genome for all three species with pan-genome sizes of 9181, 7214 and 6884 genes for A. hydrophila, A. veronii and A. caviae, respectively. Core-genome: pan-genome ratio (RCP) indicated greater genomic diversity for A. hydrophila and interestingly RCP emerged as an effective indicator to gauge genomic diversity which could possibly be extended to other organisms too. Phylogenomic network analysis highlighted the influence of homologous recombination and lateral gene transfer in the evolution of Aeromonas spp. Prediction of virulence factors indicated no significant difference among the three species though analysis of pathogenic potential and acquired antimicrobial resistance genes revealed greater hazards from A. hydrophila. In conclusion, the present study highlighted the usefulness of whole genome analyses to infer evolutionary cues for Aeromonas species which indicated considerable phylogenomic diversity for A. hydrophila and hitherto unknown genomic evidence for pathogenic potential of A. hydrophila compared to A. veronii and A. caviae. PMID:27075453

  4. Characterization of Virulence Properties of Aeromonas veronii Isolated from Diseased Gibel Carp (Carassius gibelio).

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    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

  5. Characterization of Virulence Properties of Aeromonas veronii Isolated from Diseased Gibel Carp (Carassius gibelio

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    Jingjing Sun

    2016-04-01

    Full Text Available 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 of Virulence Properties of Aeromonas veronii Isolated from Diseased Gibel Carp (Carassius gibelio)

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    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

  7. Clinical isolates of Aeromonas veronii biovar veronii harbor a nonfunctional gene similar to the thermostable direct hemolysin-related hemolysin (trh) gene of Vibrio parahaemolyticus.

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    Raghunath, Pendru; Maiti, Biswajit; Shekar, Malathi; Karunasagar, Iddya; Karunasagar, Indrani

    2010-06-01

    Thermostable direct hemolysin-related hemolysin encoded by the trh gene is considered a major virulence factor in the pathogenesis of Vibrio parahaemolyticus infections. In this study, we report the presence of a trh homolog in three clinical isolates of Aeromonas veronii biovar veronii. The presence of a trh homolog in these strains of A. veronii was confirmed by PCR, followed by cloning, sequencing and colony hybridization using a digoxigenin-labelled probe. DNA sequence analysis revealed that the A. veronii trh gene had an identity of 99% and 84% to the trh1 and trh2 genes of V. parahaemolyticus, respectively. However, the expression of a trh-like gene in A. veronii could not be detected by reverse transcription PCR. Hence, the role of the gene product in the virulence of A. veronii strains is not clear. Further, these A. veronii isolates were negative for the ure gene encoding urease and the transposase gene by PCR. These genes are part of the trh gene cluster in V. parahaemolyticus. However, the presence of a trh homolog in a pathogen other than V. parahaemolyticus points to the fact that detection of the trh gene in stool samples, seafood enrichments or environmental samples does not always imply that trh-carrying V. parahaemolyticus are present. PMID:20636974

  8. Detection and characterization of virulence genes and integrons in Aeromonas veronii isolated from catfish.

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    Nawaz, Mohamed; Khan, Saeed A; Khan, Ashraf A; Sung, Kidon; Tran, Quynhtien; Kerdahi, Khalil; Steele, Roger

    2010-05-01

    The presence of virulence genes and integrons was determined in 81 strains of Aeromonas veronii isolated from farm-raised catfish. Polymerase chain reaction (PCR) protocols were used to determine the presence of genes for cytotoxic enterotoxin (act), aerolysin (aerA), two cytotonic enterotoxins (ast, alt), lipase (lip), glycerophospholipid:cholesterol acyltransferase (gcaT), serine protease (ser), DNases (exu), elastase (ahyB) and the structural gene flagellin (fla) in the template DNA. Oligonucleotide primers amplified a 231-bp region of the act gene from the template DNA of 97.0% of the isolates. Primers specific for the amplification of the aerA gene amplified a 431-bp region of the aerA gene from the template DNA of 96.0% of the isolates. None of the isolates contained ast or alt genes. Oligonucleotide primers specific for the amplification of lip, gcaT, ser and fla genes, amplified their respective amplicons from 85.0, 78.0, 82.0 and 80.0% of the isolates. None of the isolates contained exu or the elastase genes. Several of the isolates (48.0%) contained class I integrons that confer resistance to multiple antibiotics; various sizes between 0.6 and 3.1 kb were found. None of the isolates contained Class II integrons. Our results indicate that farm-raised catfish may be a source of pathogenic A. veronii and that the potential health risks posed by virulent strains of A. veronii should not be underestimated. PMID:20227596

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

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

    2015-01-01

    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. PMID:26635240

  10. Complete genome sequence of the fish pathogen Aeromonas veronii TH0426 with potential application in biosynthesis of pullulanase and chitinase.

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    Kang, Yuanhuan; Pan, Xiaoyi; Xu, Yang; Siddiqui, Shahrood A; Wang, Chunfeng; Shan, Xiaofeng; Qian, Aidong

    2016-06-10

    Aeromonas veronii TH0426 is a pathogen of the farmed yellow catfish Pelteobagrus fulvidraco but shows high-level expression of pullulanase and chitinase. Here, we present its genome sequence, which is the first reported complete genome of fish pathogen in A. veronii to date. Strain TH0426 harbors a single circular 4,923,009bp chromosome with a GC content of 58.25%. There are 4525 genes identified on its genome, including 4244 protein-coding genes, 32 rRNA genes, 120 tRNA genes, a noncoding RNA and 128 pseudo genes. We believe that the genomic information of A. veronii TH0426 would facilitate to reveal its pathogenic mechanism associated with yellow catfish, develop vaccine to decrease economic losses for fish farming, meanwhile explore the potential application in producing pullulanase and chitinase. PMID:27080448

  11. Humoral immune response and TLR9 gene expression in Pacific red snapper (Lutjanus peru) experimentally exposed to Aeromonas veronii.

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    Reyes-Becerril, Martha; Angulo, Carlos; Ascencio, Felipe

    2015-02-01

    Aquaculture production of Pacific red snapper Lutjanus peru is growing rapidly in Mexico, especially in Gulf of California. As it is a relatively new aquaculture species there are few reports evaluating its immune response to pathogens. The Gram-negative bacteria Aeromonas veronii is a heterogeneous organism that causes the disease known as motile aeromonad septicemia, which is responsible for serious economic loss in seabream culture due to bacterial infections. For the purpose of this study, juvenile Pacific red snapper specimens were intraperitoneally injected with low doses of A. veronii (1 × 10(6) CFU ml(-1)). Changes in humoral immune parameters (total protein, myeloperoxidase, lisozyme and antiprotease activities and IgM levels), as well as superoxide dismutase and catalase activities, and TLR9 gene expression were evaluated 24 and 48 h after injection. Overall, the results showed an enhanced in humoral immune parameters and SOD and CAT activities in fish infected with A. veronii compared with control group at 24 or 48 h. By real time PCR assays, the basal mRNA transcripts of TLR9 showed that were highly expressed in intestine and leucocytes compared to skin, head kidney, liver and gill. Then, the mRNA expression levels of TLR9 in head kidney, skin, liver and intestine were analyzed in non-infected and experimentally infected fish 24 and 48 h after injection. A. veronii up-regulated the expression of TLR9 at 24 or 48 h of exposure in all samples analyzed except in liver. Interestingly, intestine produced the greatest increase in transcript levels upon exposure (48 h) to A. veronii. Taken together, our results suggest that low doses of A. veronii infection inducing humoral immune system and TLR9 immune gene in Pacific red snapper that can be useful in the health control of this species. PMID:25462554

  12. 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.

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    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. PMID:25411168

  13. Prevalence and characterization of plasmid-mediated quinolone resistance genes in Aeromonas spp. isolated from South African freshwater fish.

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    Chenia, Hafizah Yousuf

    2016-08-16

    An increasing incidence of multidrug-resistant Aeromonas spp., which are both fish and emerging opportunistic human pathogens, has been observed worldwide. Quinolone-resistant Aeromonas spp. isolates are increasingly being observed in clinical and environmental settings, and this has been attributed primarily to target gene alterations, efflux, and transferable quinolone resistance. Thirty-four Aeromonas spp., obtained from freshwater aquaculture systems, were screened for the presence of GyrA and ParC substitutions, efflux activity and the prevalence of plasmid-mediated quinolone resistance genes, qnr and aac-6'-Ib-cr. Although 44% of isolates were resistant to nalidixic acid, the majority were susceptible to ciprofloxacin and ofloxacin. The predominant GyrA substitution was Ser-83→Val among Aeromonas veronii isolates whilst Aeromonas hydrophila isolates displayed a Ser-83→Ile substitution, and Ser-80→Ile substitutions were observed in ParC. Minimum inhibitory concentrations of fluoro(quinolones) were determined in the presence and absence of the efflux pump inhibitor, phenylalanine-arginine β-naphthylamide (PAβN). Addition of PAβN had no effect on the levels of fluoro(quinolone) resistance observed for these isolates. Although no aac-6'-Ib-cr variant genes were identified, qnrB and qnrS were detected for 41% and 24% of isolates, respectively, by Southern hybridization and confirmed by PCR and sequencing. Quinolone resistance in these fish-associated Aeromonas isolates was related to mutations in the quinolone resistance determining regions of GyrA and ParC and presence of qnrB and qnrS. The presence of qnr alleles in Aeromonas spp. isolates may facilitate high-level fluoroquinolone resistance and potentially serve as reservoirs for the dissemination of qnr genes to other aquatic microbes. PMID:27180024

  14. Improvement of methyl orange dye biotreatment by a novel isolated strain, Aeromonas veronii GRI, by SPB1 biosurfactant addition.

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    Mnif, Inès; Maktouf, Sameh; Fendri, Raouia; Kriaa, Mouna; Ellouze, Semia; Ghribi, Dhouha

    2016-01-01

    Aeromonas veronii GRI (KF964486), isolated from acclimated textile effluent after selective enrichment on azo dye, was assessed for methyl orange biodegradation potency. Results suggested the potential of this bacterium for use in effective treatment of azo-dye-contaminated wastewaters under static conditions at neutral and alkaline pH value, characteristic of typical textile effluents. The strain could tolerate higher doses of dyes as it was able to decolorize up to 1000 mg/l. When used as microbial surfactant to enhance methyl orange biodecolorization, Bacillus subtilis SPB1-derived lipopeptide accelerated the decolorization rate and maximized slightly the decolorization efficiency at an optimal concentration of about 0.025%. In order to enhance the process efficiency, a Taguchi design was conducted. Phytotoxicity bioassay using sesame and radish seeds were carried out to assess the biotreatment effectiveness. The bacterium was able to effectively decolorize the azo dye when inoculated with an initial optical density of about 0.5 with 0.25% sucrose, 0.125% yeast extract, 0.01% SPB1 biosurfactant, and when conducting an agitation phase of about 24 h after static incubation. Germination potency showed an increase toward the nonoptimized conditions indicating an improvement of the biotreatment. When comparing with synthetic surfactants, a drastic decrease and an inhibition of orange methyl decolorization were observed in the presence of CTAB and SDS. The nonionic surfactant Tween 80 had a positive effect on methyl orange biodecolorization. Also, studies ensured that methyl orange removal by this strain could be due to endocellular enzymatic activities. To conclude, the addition of SPB1 bioemulsifier reduced energy costs by reducing effective decolorization period, biosurfactant stimulated bacterial decolorization method may provide highly efficient, inexpensive, and time-saving procedure in treatment of textile effluents. PMID:26396008

  15. A Tale of Transmission: Aeromonas veronii Activity within Leech-Exuded Mucus.

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    Ott, Brittany M; Dacks, Andrew M; Ryan, Kenneth J; Rio, Rita V M

    2016-05-01

    Transmission, critical to the establishment and persistence of host-associated microbiotas, also exposes symbionts to new environmental conditions. With horizontal transmission, these different conditions represent major lifestyle shifts. Yet genome-wide analyses of how microbes adjust their transcriptomes toward these dramatic shifts remain understudied. Here, we provide a comprehensive and comparative analysis of the global transcriptional profiles of a symbiont as it shifts between lifestyles during transmission. The gammaproteobacteriumAeromonas veroniiis transmitted from the gut of the medicinal leech to other hosts via host mucosal castings, yetA. veroniican also transition from mucosal habitancy to a free-living lifestyle. These three lifestyles are characterized by distinct physiological constraints and consequently lifestyle-specific changes in the expression of stress-response genes. Mucus-boundA. veroniihad the greatest expression in terms of both the number of loci and levels of transcription of stress-response mechanisms. However, these bacteria are still capable of proliferating within the mucus, suggesting the availability of nutrients within this environment. We found thatA. veroniialters transcription of loci in a synthetic pathway that obtains and incorporatesN-acetylglucosamine (NAG; a major component of mucus) into the bacterial cell wall, enabling proliferation. Our results demonstrate that symbionts undergo dramatic local adaptation, demonstrated by widespread transcriptional changes, throughout the process of transmission that allows them to thrive while they encounter new environments which further shape their ecology and evolution. PMID:26896136

  16. Identification and Characterization of Pathogenic Aeromonas veronii Biovar Sobria Associated with Epizootic Ulcerative Syndrome in Fish in Bangladesh

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    Rahman, Mokhlasur; Colque-Navarro, Patricia; Kühn, Inger; Huys, Geert; Swings, Jean; Möllby, Roland

    2002-01-01

    Sparse information is available on the virulence factors of Aeromonas strains isolated from diseased fish, from the environment, and from humans. In the present study, 52 Aeromonas isolates obtained from epizootic ulcerative syndrome (EUS) lesions in fish, from the aquatic environment, and from children with diarrhea in Bangladesh were identified by biochemical phenotyping (i.e., PhenePlate [PhP] typing) and DNA fingerprinting and then characterized with respect to certain putative virulence ...

  17. X-ray Absorption Spectroscopy of the Zinc-Binding Sites in the Class B2 Metallo-B-lactamsase ImiS from Aeromonas veronii bv. sobria

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    Costello,A.; Sharma, N.; Yang, K.; Crowder, M.; Tierney, D.

    2006-01-01

    X-ray absorption spectroscopy was used to investigate the metal-binding sites of ImiS from Aeromonas veronii bv. sobria in catalytically active (1-Zn), product-inhibited (1-Zn plus imipenem), and inactive (2-Zn) forms. The first equivalent of zinc(II) was found to bind to the consensus Zn{sub 2} site. The reaction of 1-Zn ImiS with imipenem leads to a product-bound species, coordinated to Zn via a carboxylate group. The inhibitory binding site of ImiS was examined by a comparison of wild-type ImiS with 1 and 2 equiv of bound zinc. 2-Zn ImiS extended X-ray absorption fine structure data support a binding site that is distant from the active site and contains both one sulfur donor and one histidine ligand. On the basis of the amino acid sequence of ImiS and the crystal structure of CphA [Garau et al. (2005) J. Mol. Biol. 345, 785-795], we propose that the inhibitory binding site is formed by M146, found on the B2-distinct {alpha}3 helix, and H118, a canonical Zn{sub 1} ligand, proposed to help activate the nucleophilic water. The mutation of M146 to isoleucine abolishes metal inhibition. This is the first characterization of ImiS with the native metal Zn and establishes, for the first time, the location of the inhibitory metal site.

  18. Symbiosis of Aeromonas veronii Biovar sobria and Hirudo medicinalis, the Medicinal Leech: a Novel Model for Digestive Tract Associations

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    Graf, Joerg

    1999-01-01

    Hirudo medicinalis, the medicinal leech, is applied postoperatively in modern medicine. Infections by Aeromonas occur in up to 20% of patients unless a preemptive antibiotic treatment is administered. The associated infections demonstrate the need for a better understanding of the digestive tract flora of H. medicinalis. Early studies reported the presence of a single bacterial species in the digestive tract and suggested that these bacteria were endosymbionts contributing to the digestion of...

  19. Susceptibility to antimicrobial agents and plasmid carrying in Aeromonas hydrophila isolated from two estuarine systems.

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    Montoya, R; Dominguez, M; Gonzalez, C; Mondaca, M A; Zemelman, R

    1992-01-01

    Susceptibility to various antimicrobial agents and the presence of plasmids was investigated in eleven strains of Aeromonas hydrophila isolated from samples of sea water and these strains isolated from Aulacomya ater. Transference of resistance to Escherichia coli was attempted by conjugation and transformation experiments. The strains showed multiple resistance toward beta-lactam antibiotics and susceptibility to other antimicrobial agents. Five strains harboured plasmids with molecular weights below 5.7 MD. It was not possible to relate the resistance of the strains with the presence of their plasmids. PMID:1593967

  20. Class D tetracycline resistance determinants of R plasmids from the fish pathogens Aeromonas hydrophila, Edwardsiella tarda, and Pasteurella piscicida.

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    Aoki, T.; Takahashi, A.

    1987-01-01

    Tetracycline resistance determinants of R plasmids from the fish pathogens Aeromonas hydrophila, Edwardsiella tarda, and Pasteurella piscicida were classified as class D by their expression of resistance to tetracycline and minocycline and through their DNA structure.

  1. Draft genome sequences of two Aeromonas salmonicida subsp. salmonicida isolates harboring plasmids conferring antibiotic resistance.

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    Vincent, Antony T; Tanaka, Katherine H; Trudel, Melanie V; Frenette, Michel; Derome, Nicolas; Charette, Steve J

    2015-02-01

    The bacterium Aeromonas salmonicida is the etiological agent of furunculosis, a widespread fish disease causing important economic losses to the fish farming industry. Antibiotic treatments in fish farms may be challenging given the existence of multidrug-resistant isolates of this bacterium. Here, we report the draft genome sequences of the 2004-05MF26 and 2009-144K3 isolates, which harbor plasmids conferring antibiotic resistance. Both isolates also carry the large plasmid pAsa5, which is known to encode a type three secretion system (TTSS) and the pAsal1 plasmid which has the aopP gene producing a TTSS effector. These two isolates are good representatives of the plasmid diversity in A. salmonicida subsp. salmonicida. PMID:25724776

  2. 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

  3. Diversity and Homogeneity among Small Plasmids of Aeromonas salmonicida subsp. salmonicida Linked with Geographical Origin

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    Attéré, Sabrina A.; Vincent, Antony T.; Trudel, Mélanie V.; Chanut, Romain; Charette, Steve J.

    2015-01-01

    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 for pAsa3 and p

  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.; Dalsgaard, Inger

    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...... sulphadiazine, trimethoprim and streptomycin resistances were invariably encoded by integrons. It thus appears that integron-encoded antibiotic resistance genes contribute substantially to the horizontal spread of antimicrobial resistance within this species, being associated with conjugative plasmids....

  5. Complete Sequences of IncU Plasmids Harboring Quinolone Resistance Genes qnrS2 and aac(6')-Ib-cr in Aeromonas spp. from Ornamental Fish.

    Science.gov (United States)

    Dobiasova, Hana; Videnska, Petra; Dolejska, Monika

    2016-01-01

    The nucleotide sequences of three IncU plasmids from Aeromonas spp. isolated from ornamental fish are described. They had a typical IncU backbone for plasmid replication and maintenance functions, but conjugative transfer modules were disrupted. The gene qnrS2 was inserted into mpR as a mobile insertion cassette. Novel Tn3 family transposons carrying putative toxin-antitoxin and plasmid stability genes were identified. The study demonstrates high plasticity of IncU plasmids from aquatic environments. PMID:26525788

  6. 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

    ) and plasmid profiles. Most epidemiologically unrelated strains had different ribotypes, whereas isolates from the same outbreak were identical. All strains, except one, carried one or more large plasmids (>55 kbp) and all strains, except two, additionally carried one or more smaller plasmids. Many strains...... isolated from the same outbreak showed different plasmid profiles although some plasmids were identical. The results suggest the existence of several atypical Aer, salmonicida. It also seems that ribotypes are stable properties for these bacteria while the plasmids are more labile....

  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. Emerging pathogens: Aeromonas spp.

    Science.gov (United States)

    Merino, S; Rubires, X; Knochel, S; Tomas, J M

    1995-12-01

    Aeromonas spp. are Gram-negative rods of the family Vibrionaceae. They are normal water inhabitants and are part of the regular flora of poiquilotherm and homeotherm animals. They can be isolated from many foodstuffs (green vegetables, raw milk, ice cream, meat and seafood). Mesophilic Aeromonas spp. have been classified following the AeroKey II system (Altwegg et al., 1990; Carnahan et al., 1991). The major human diseases caused by Aeromonas spp. can be classified in two major groups: septicemia (mainly by strains of A. veronii subsp. sobria and A. hydrophila), and gastroenteritis (any mesophilic Aeromonas spp. but principally A. hydrophila and A. veronii). Most epidemiological studies have shown Aeromonas spp. in stools to be more often associated with diarrhea than with the carrier state; an association with the consumption of untreated water was also conspicuous. Acute self-limited diarrhea is more frequent in young children, in older patients chronic enterocolitis may also be observed. Fever, vomiting, and fecal leukocytes or erythrocytes (colitis) may be present (Janda, 1991). The main putative virulence factors are: exotoxins, endotoxin (LPS), presence of S-layers, fimbriae or adhesins and the capacity to form capsules. PMID:8750664

  9. The involvement of tetA and tetE tetracycline resistance genes in plasmid and chromosomal resistance of Aeromonas in Brazilian strains

    Directory of Open Access Journals (Sweden)

    Ilana Teruszkin Balassiano

    2007-11-01

    Full Text Available This study analyzed the involvement of tetA and tetE genes in the tetracycline resistance of 16 strains of genus Aeromonas, isolated from clinical and food sources. Polymerase chain reactions revealed that 37.5% of the samples were positive for tetA, and also 37.5% were tetE positive. One isolate was positive for both genes. Only the isolate A. caviae 5.2 had its resistance associated to the presence of a plasmid, pSS2. The molecular characterization of pSS2 involved the construction of its restriction map and the determination of its size. The digestion of pSS2 with HindIII originated two fragments (A and B that were cloned separately into the pUC18 vector. The tetA gene was shown to be located on the HindIII-A fragment by PCR. After transforming a tetracycline-sensitive strain with pSS2, the transformants expressed the resistance phenotype and harbored a plasmid whose size was identical to that of pSS2. The results confirmed the association between pSS2 and the tetracycline resistance phenotype, and suggest a feasible dissemination of tetA and tetE among strains of Aeromonas. This study suggests the spreading tetA and tetE genes in Aeromonas in Brazil and describes a resistance plasmid that probably contributes to the dissemination of the resistance.

  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. Detection of variants of the pRAS3, pAB5S9, and pSN254 plasmids in Aeromonas salmonicida subsp. salmonicida: multidrug resistance, interspecies exchanges, and plasmid reshaping.

    Science.gov (United States)

    Vincent, Antony T; Trudel, Mélanie V; Paquet, Valérie E; Boyle, Brian; Tanaka, Katherine H; Dallaire-Dufresne, Stéphanie; Daher, Rana K; Frenette, Michel; Derome, Nicolas; Charette, Steve J

    2014-12-01

    The ubiquitous water-borne Gram-negative bacterium Aeromonas salmonicida subsp. salmonicida is the causative agent of furunculosis, a worldwide disease in fish farms. Plasmids carrying antibiotic resistance genes have already been described for this bacterium. The aim of the present study was to identify and characterize additional multidrug resistance plasmids in A. salmonicida subsp. salmonicida. We sequenced the plasmids present in two multiple antibiotic-resistant isolates using high-throughput technologies. We also investigated 19 other isolates with various multidrug resistance profiles by genotyping PCR and assessed their resistance to tetracycline. We identified variants of the pAB5S9 and pSN254 plasmids that carry several antibiotic resistance genes and that have been previously reported in bacteria other than A. salmonicida subsp. salmonicida, which suggests a high level of interspecies exchange. Genotyping analyses and the antibiotic resistance profiles of the 19 other isolates support the idea that multiple versions of pAB5S9 and pSN254 exist in A. salmonicida subsp. salmonicida. We also identified variants of the pRAS3 plasmid. The present study revealed that A. salmonicida subsp. salmonicida harbors a wide variety of plasmids, which suggests that this ubiquitous bacterium may contribute to the spread of antibiotic resistance genes in the environment. PMID:25267667

  12. 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...

  13. [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

  14. 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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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

  16. 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.

  17. 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%.

  18. Recombinant goose-type lysozyme in channel catfish: lysozyme activity and efficacy as plasmid DNA immunostimulant against Aeromonas hydrophila infection

    Science.gov (United States)

    The objectives of this study were: 1) to investigate whether recombinant channel catfish lysozyme g (CC-Lys-g) produced in E. coli expression system possesses any lysozyme activity; and 2) to evaluate whether channel catfish lysozyme g plasmid DNA could be used as an immunostimulant to protect chann...

  19. Adhesion of Aeromonas sp. to cell lines used as models for intestinal adhesion.

    OpenAIRE

    Kirov, S M; Hayward, L. J.; Nerrie, M. A.

    1995-01-01

    Adhesion to HEp-2 cells has been shown to correlate with enteropathogenicity for Aeromonas species. Such adhesion is thought to reflect the ability of strains to adhere to human intestinal enterocytes, although HEp-2 cells are not of intestinal origin. In this study strains of Aeromonas veronii biotype sobria isolated from various sources were investigated in parallel assays for their ability to adhere to HEp-2 cells and to an intestinal cell line (Caco-2). Quantitative assays showed identica...

  20. 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. PMID:26971634

  1. The occurrence of enteric pathogens and Aeromonas species in organic vegetables.

    Science.gov (United States)

    McMahon, M A; Wilson, I G

    2001-10-22

    A range of commercially available organic vegetables (n = 86) was examined for the presence of Salmonella, Campylobacter, Escherichia coli, E. coli O 157. Listeria and Aeromonas spp., to provide information on the occurrence of such organisms in organic vegetables in Northern Ireland. The study was not designed to quantify such organisms or to compare occurrence with conventionally farmed vegetables. Standard enrichment techniques were used to isolate and identify enteric pathogens and Aeromonas species. No Salmonella, Campylobacter, E. coli. E. coli O 157, Listeria were found in any of the samples examined. Aeromonas species were isolated from 34% of the total number of organic vegetables examined. Many (64%) of the organic vegetables examined were "ready-to-eat" after minimal processing, i.e., washing. Aeromonas spp. was isolated from 41% of these vegetables. Aeromonas spp. was not recovered from certain vegetable types. The most commonly isolated species of Aeromonas was Aeromonas schubertii with 21.0% of all samples contaminated with this species; 5.8% of samples contained A. hydrophila, 5.8% A. trota, 3.5% A. caviae and 2.3% contained A. veronii biovar veronii. Although Aeromonas species are frequently detected in organic vegetables, the absence of accepted enteric pathogens was encouraging, and does not support the allegation of organic foods being of high risk due to the farming methods used. PMID:11759753

  2. Distribution of cphA or related carbapenemase-encoding genes and production of carbapenemase activity in members of the genus Aeromonas.

    OpenAIRE

    G.M. Rossolini; Zanchi, A.; Chiesurin, A; Amicosante, G; Satta, G; Guglielmetti, P

    1995-01-01

    The prevalence of the cphA gene or related carbapenemase-encoding genes was investigated in 114 Aeromonas strains belonging to the six species of major clinical interest. A species-related distribution of cphA-related sequences was observed. Similar sequences were found in A. hydrophila, A. veronii bv. sobria, A. veronii bv. veronii, and A. jandaei, but not in A. caviae, A. trota, or A. schubertii. However, a single A. caviae strain (of 62 tested) was found carrying cphA-related sequences, su...

  3. Impact of antibiotic treatments on the expression of the R plasmid tra genes and on the host innate immune activity during pRAS1 bearing Aeromonas hydrophila infection in zebrafish (Danio rerio

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    Cantas Leon

    2012-03-01

    Full Text Available Abstract Background The transfer of R plasmids between bacteria has been well studied under laboratory conditions and the transfer frequency has been found to vary between plasmids and under various physical conditions. For the first time, we here study the expression of the selected plasmid mobility genes traD, virB11 and virD4 in the 45 kb IncU plasmid, pRAS1, conferring resistance to tetracycline, trimethoprim and sulphonamide, using an in vivo zebrafish infection- treatment model. Results Three days after oral infection of adult zebrafish with Aeromonas hydrophila harboring pRAS1, elevated expression of pro-inflammatory cytokine (TNF α, IL-1β and IL-8 and complement C3 genes in the intestine coincided with disease symptoms. Tetracycline, trimethoprim and an ineffective concentration of flumequine given 48 h prior to sampling, strongly increased expression of plasmid mobility genes, whereas an effective dosage of flumequine resulted in lower levels of mRNA copies of these genes relative to placebo treatment. Following effective treatment with flumequine, and ineffective treatments with a low concentration of flumequine, with trimethoprim or with sulphonamide, the intestinal expression of immune genes was strongly induced compared to placebo treated control fish. Conclusions Treatment of zebrafish infected with an antibiotic resistant (TcR, TmR, SuR A. hydrophila with ineffective concentrations of flumequine or the ineffective antimicrobials tetracycline and trimethoprim strongly induced expression of genes mediating conjugative transfer of the R-plasmid pRAS1. Simultaneously, there was a strong induction of selected inflammatory and immune response genes, which was again evident in fish subjected to ineffective treatment protocols. Our findings point to the essential role of therapeutic practices in escalation or control of antibiotic resistance transfer, and suggest that antibiotic substances, even in sub-inhibitory concentrations, may

  4. Rapid detection of virulence factors of Aeromonas isolated from a trout farm by hexaplex-PCR.

    Science.gov (United States)

    Nam, In-Young; Joh, Kiseong

    2007-08-01

    The detection of virulence factors of Aeromonas is a key component in determining potential pathogenicity because these factors act multifunctionally and multifactorially. In this study water samples were collected from a trout farm on a seasonal basis, and diseased fish and Aeromonas species were isolated and identified. For rapid detection of six virulence factors of isolated Aeromonas, a hexaplex-polymerase chain reaction (hexaplex-PCR) assay was used. The detected virulence factors include aerolysin (aer), GCAT (gcat), serine protease (ser), nuclease (nuc) lipase (lip) and lateral flagella (laf). The dominant strain found in our isolates was Aeromonas sobria, and the dominant virulence factors were aer and nuc for all seasons. We confirmed that A. sobria and two of the virulence genes (aer and nuc) are related. We proposed a method by which one can identify the major strains of Aeromonas: A. hydrophila, A. sobria, A. caviae, and A. veronii, using hexaplex-PCR. PMID:17846582

  5. [Prevalence of Aeromonas spp. in surface water].

    Science.gov (United States)

    Hernández, P; Rodríguez de García, R

    1997-03-01

    Some Aeromonas strains are well recognized enteropathogens according to microbiological, clinical, immunological and epidemiological evidence. The main source of infection seems to be untreated water, these microorganisms can be found in virtually all aquatic environments. Additionally, some Aeromonas, which include enterotoxigenic strains, are capable of rapid growth at 5 degrees C and even of producing toxins. Vegetable products irrigated with contaminated water may reach critical Aeromonas levels after being kept under refrigeration, this could represent a public health risk when they are consumed as uncooked salads. This study was pursued to evaluate such risk. Surface water samples were streaked on starch ampicillin and inositol-brilliant green-bile salts agar dishes. In addition, 100 ml of each sample were filtered through a 0.45 micron Millipore membrane filter. The filters were incubated on alkaline peptone water as enrichment media during 24 h at 35 degrees C. Enrichment broth was then streaked on the selective agars above mentioned. Isolates from both tests were identified using the API 20 E System. The prevalence of Aeromonas strains in the analyzed samples was 17.8%. A higher isolation rate was observed after the enrichment technique. Starch ampicillin agar showed a higher recuperation rate. A Veronii biotype sobria (formerly A. sobria) was isolated with higher frequency. Since this species has been associated with the greatest virulence, the use of contaminated water to irrigate vegetable products that are to be kept under refrigeration and consumed without ulterior cooking may represent a risk to the public health. PMID:9429640

  6. Characterisation of Aeromonas spp. isolated from frozen fish intended for human consumption in Mexico.

    Science.gov (United States)

    Castro-Escarpulli, G; Figueras, M J; Aguilera-Arreola, G; Soler, L; Fernández-Rendón, E; Aparicio, G O; Guarro, J; Chacón, M R

    2003-07-15

    A total of 82 strains of presumptive Aeromonas spp. were identified biochemically and genetically (16S rDNA-RFLP). The strains were isolated from 250 samples of frozen fish (Tilapia, Oreochromis niloticus niloticus) purchased in local markets in Mexico City. In the present study, we detected the presence of several genes encoding for putative virulence factors and phenotypic activities that may play an important role in bacterial infection. In addition, we studied the antimicrobial patterns of those strains. Molecular identification demonstrated that the prevalent species in frozen fish were Aeromonas salmonicida (67.5%) and Aeromonas bestiarum (20.9%), accounting for 88.3% of the isolates, while the other strains belonged to the species Aeromonas veronii (5.2%), Aeromonas encheleia (3.9%) and Aeromonas hydrophila (2.6%). Detection by polymerase chain reaction (PCR) of genes encoding putative virulence factors common in Aeromonas, such as aerolysin/hemolysin, lipases including the glycerophospholipid-cholesterol acyltransferase (GCAT), serine protease and DNases, revealed that they were all common in these strains. Our results showed that first generation quinolones and second and third generation cephalosporins were the drugs with the best antimicrobial effect against Aeromonas spp. In Mexico, there have been few studies on Aeromonas and its putative virulence factors. The present work therefore highlights an important incidence of Aeromonas spp., with virulence potential and antimicrobial resistance, isolated from frozen fish intended for human consumption in Mexico City. PMID:12781953

  7. Incidence and identification of mesophilic Aeromonas spp. from retail foods.

    Science.gov (United States)

    Neyts, K; Huys, G; Uyttendaele, M; Swings, J; Debevere, J

    2000-11-01

    Sixty-eight food samples were examined for the presence of mesophilic Aeromonas species both qualitatively and quantitatively. Aeromonads were isolated from 26% of the vegetable samples, 70% of the meat and poultry samples and 72% of the fish and shrimps. Numbers of motile aeromonads present in the food samples varied from 10(5) cfu g(-1). GLC analysis of FAMEs was used to identify a selection of presumptive Aeromonas colonies to fenospecies or genomic species level. Aeromonas strains belonging to the Aer. caviae complex, which also includes the potentially pathogenic genospecies HG4, were mostly isolated from vegetables but were also found in meat, poultry and fish. In addition, three strains of the virulent taxon Aer. veronii biovar sobria HG8 were isolated from poultry and minced meat. All members of the Aer. hydrophila complex, predominant in the fish, meat and poultry samples, were classified in the non-virulent taxon HG3. Although the significance of Aeromonas in foods remains undefined, the isolation of Aeromonas HG4 and HG8 strains from a variety of retail foods may indicate that these products can act as possible vehicles for the dissemination of food-borne Aeromonas gastroenteritis. PMID:11069637

  8. 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.

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

    International Nuclear Information System (INIS)

    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 oC 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 oC 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.

  10. 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.

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

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    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.

  12. Aeromonas dhakensis, an Increasingly Recognized Human Pathogen.

    Science.gov (United States)

    Chen, Po-Lin; Lamy, Brigitte; Ko, Wen-Chien

    2016-01-01

    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 ββ-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. PMID:27303382

  13. Aeromonas dhakensis, an increasingly recognized human pathogen

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    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.

  14. Medicinal leech therapy and Aeromonas spp. infection.

    Science.gov (United States)

    Verriere, B; Sabatier, B; Carbonnelle, E; Mainardi, J L; Prognon, P; Whitaker, I; Lantieri, L; Hivelin, M

    2016-06-01

    While the use of medicinal leech therapy (MLT) in reconstructive and orthopaedic surgery is widely described, post-operative complications related to leeches remain a major concern. Aeromonas spp. strains are involved in the majority of reported cases. As surgical success rate is directly impacted, an adapted antibiotic prophylaxis should be instituted in order to minimize these complications. We assessed pharmaceutical process, microbiological control and related infections in order to provide data and choose the appropriate antibiotherapy for patients requiring MLT. We report a clinical and microbiological study over a 24-month period. Clinical data were collected from patients' database, and microbiological analysis both on leeches' tank water and crushed leeches were performed to characterize isolated strains and their susceptibility to antibiotics. A total of 595 leeches were used to treat 28 patients (12 in plastic surgery and 16 in orthopaedic surgery), and three documented cases of post-operative infections were reported. Aeromonas spp. isolates yielded from 62 % of analyzed batches (75 % of Aeromonas veronii). Eighteen Aeromonas spp. isolates yielded from 23 water samples and three crushed leeches. Isolates were similar in tank and crushed leeches. Strains were susceptible to fluoroquinolones, sulfamethoxazole/trimethoprim, aminosides, and third-generation cephalosporins but resistant to amoxicillin/clavulanic acid and second-generation cephalosporins. According to collected data, routine tank water microbiological analyses are mandatory in order to identify leeches' batches containing resistant strains and to discard them. In this context, the surgeon is able to select an appropriated antibiotic prophylaxis in order to avoid MLT associated serious post-operative complications. PMID:27039338

  15. Modification of the bile salts-Irgasan-brilliant green agar for enumeration of Aeromonas species from food.

    Science.gov (United States)

    Neyts, K; Notebaert, E; Uyttendaele, M; Debevere, J

    2000-06-15

    The present study evaluated the productivity of BIBG medium for the isolation of Aeromonas spp. from food and describes a modification of the BIBG medium (mBIBG) (increased pH (8.7), replacement of xylose by soluble starch as a carbon source, decreased concentration of bile salts) to increase its selectivity and electivity. Using the mBIBG medium, growth of the majority of the Enterobacteriaceae (9/10) was suppressed except for Citrobacter freundii. The mBIBG medium supported growth of Pseudomonas species but a clear distinction between Aeromonas and Pseudomonas colonies could be made. Interpretation of the mBIBG medium should be performed after 24 h of incubation. It was noted that three of the 27 Aeromonas strains tested did not develop on the mBIBG medium. The ability or inability to grow on a selective medium is strain-dependent. Enumeration of Aeromonas species (A. hydrophila LMG 3771, A. caviae LMG 3775, A. veronii biovar veronii LMG 9075, A. veronii biovar sobria LMG 13071) from artificially contaminated foods (shrimp, minced meat (beef/pork), precut leek, and shredded carrots) confirmed that the mBIBG medium is suitable for quantitative recovery of aeromonads (ca. 10(2)-10(7) cfu/g) in the presence of a high background flora (10(5)-10(6) cfu/g). Screening of naturally contaminated foods (vegetables, seafood, meat) for the presence of Aeromonas resulted in three out of 14 food samples showing presumptive Aeromonas colonies on mBIBG. PMID:10868682

  16. 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.

  17. Genospecies and virulence factors of Aeromonas species in different sources in a North African country

    Science.gov (United States)

    Ghenghesh, Khalifa Sifaw; Ahmed, Salwa F.; Cappuccinelli, Piero; Klena, John D.

    2014-01-01

    Introduction Aeromonads of medical importance have been reported from numerous clinical, food, and water sources, but identification of genospecies and virulence factors of Aeromonas species from countries in North Africa and the Middle East are few. Methods In total 99 Aeromonas species isolates from different sources (diarrheal children [n=23], non-diarrheal children [n=16], untreated drinking water from wells [n=32], and chicken carcasses [n=28]) in Tripoli, Libya, were included in the present investigation. Genus identification was confirmed by biochemical analysis, and genospecies were determined using a combination of 16S rDNA variable region and gyrB sequence analysis. Polymerase chain reaction (PCR) was used to detect genes encoding toxins from 52 of the isolates. Results We identified 44 isolates (44%) as A. hydrophila (3 [3.0%] subspecies anaerogenes, 23 [23%] subspecies dhakensis, and 18 [18%] subspecies ranae); 27 isolates (27%) as A. veronii; 23 isolates (23%) as A. caviae; and 5 isolates (5.0%) as other genospecies. The genes encoding aerolysin (aer), cytolytic enterotoxin (act), and A. hydrophila isolate SSU enterotoxin (ast) were detected in 45 (87%), 4 (7.7%), and 9 (17%) of the 52 isolates tested, respectively. The gene encoding an extracellular lipase (alt) was not detected. Conclusion The majority of aeromonads from Libya fall within three genospecies (i.e. A. hydrophila, A. veronii, and A. caviae), and genes coding for toxin production are common among them. PMID:25216211

  18. Genospecies and virulence factors of Aeromonas species in different sources in a North African country

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    Khalifa Sifaw Ghenghesh

    2014-09-01

    Full Text Available Introduction: Aeromonads of medical importance have been reported from numerous clinical, food, and water sources, but identification of genospecies and virulence factors of Aeromonas species from countries in North Africa and the Middle East are few. Methods: In total 99 Aeromonas species isolates from different sources (diarrheal children [n=23], non-diarrheal children [n=16], untreated drinking water from wells [n=32], and chicken carcasses [n=28] in Tripoli, Libya, were included in the present investigation. Genus identification was confirmed by biochemical analysis, and genospecies were determined using a combination of 16S rDNA variable region and gyrB sequence analysis. Polymerase chain reaction (PCR was used to detect genes encoding toxins from 52 of the isolates. Results: We identified 44 isolates (44% as A. hydrophila (3 [3.0%] subspecies anaerogenes, 23 [23%] subspecies dhakensis, and 18 [18%] subspecies ranae; 27 isolates (27% as A. veronii; 23 isolates (23% as A. caviae; and 5 isolates (5.0% as other genospecies. The genes encoding aerolysin (aer, cytolytic enterotoxin (act, and A. hydrophila isolate SSU enterotoxin (ast were detected in 45 (87%, 4 (7.7%, and 9 (17% of the 52 isolates tested, respectively. The gene encoding an extracellular lipase (alt was not detected. Conclusion: The majority of aeromonads from Libya fall within three genospecies (i.e. A. hydrophila, A. veronii, and A. caviae, and genes coding for toxin production are common among them.

  19. 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. PMID:22322339

  20. Aeromonas spp. e Plesiomonas shigelloides isoladas a partir de mexilhões (Perna perna in natura e pré-cozidos no Rio de Janeiro, RJ Aeromonas spp. and Plesiomonas shigelloides isolated from in natura and precooked mussels (Perna perna in Rio de Janeiro, RJ, Brazil

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    Christiane Soares Pereira

    2004-12-01

    Full Text Available O ecossistema aquático é o habitat de mexilhões (Perna perna, animais filtradores que refletem a qualidade ambiental através de análise microbiológica de sua carne. No presente trabalho avaliou-se a presença de patógenos emergentes (Aeromonas hydrophila e Plesiomonas shigelloides, em mexilhões in natura e pré-cozidos coletados por pescadores da Estação Experimental de Cultivo de Mexilhões situada em Jurujuba, Niterói, Rio de Janeiro. Foram analisadas 86 amostras de mexilhões (43 in natura e 43 pré-cozidos as quais foram submetidas a enriquecimento em Água Peptonada Alcalina (APA acrescida de 1 e 3% de Cloreto de Sódio (NaCl e em solução Salina de Butterfield, incubadas a 37ºC por 24 horas. Em seguida, foram semeadas em Ágar Seletivo para Pseudomonas-Aeromonas (GSP, Ágar Tiossulfato Citrato Bile Sacarose (TCBS e Ágar Inositol Bile Verde Brilhante (IBB. A análise geral dos resultados permitiu a identificação de Areomonas spp e Plesiomonas shigelloides em 86% das amostras de mexilhões in natura e pré-cozidas avaliadas. A posterior caracterização bioquímica permitiu a identificação das espécies Aeromonas media (37,10%, A. hydrophila (15,50%, A. caviae (14,80%, A. veronii biogrupo veronii (11,60%, Aeromonas sp. (7,36%, A. sobria (4,20%, A. trota (4,20%, A. schubertii (1,31%, A. jandaei (1,31%, A. veronii biogrupo sobria (0,52% e Plesiomonas shigelloides (2,10%. A relevância epidemiológica desses microrganismos em casos de gastrenterite humana, após consumo de mexilhões crus ou parcialmente cozidos, revela a importância de alertar as autoridades de Saúde Pública no Brasil, sobre a presença desses patógenos na cadeia alimentar e seus riscos para a saúde humana.The aquatic ecosystem is the habitat of mussels, filtrating animals that reflect the ambient quality through microbiological analysis. In the present investigation, we evaluated the presence of emergent pathogens (Aeromonas hydrophila and Plesiomonas

  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. PMID:23499189

  2. 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.

  3. The usefulness of molecular techniques to assess the presence of Aeromonas spp. harboring virulence markers in foods.

    Science.gov (United States)

    Bin Kingombe, César I; Huys, Geert; Howald, Denise; Luthi, Elisabeth; Swings, Jean; Jemmi, Thomas

    2004-07-15

    A total of 78 raw and 123 processed and ready-to-eat retail food samples were used to assess the presence of motile Aeromonas spp. harboring virulence genes (cytotoxic enterotoxin and hemolysin genes) using a recently described PCR method in comparison with the conventional cultivation method based on the use of Ampicillin-Dextrin Agar (ADA) medium. With the ADA-based method, 65/201 (32.3%) samples showed presumptive Aeromonas spp. colonies whereas the PCR method revealed the presence of Aeromonas spp. harboring the targeted virulence genes in 51/201 (25.4%) of the tested samples. The rate of contaminated samples and the presence of pathogenic Aeromonas were significantly lower with both methods for processed than in case of raw samples. A polyphasic identification approach including biochemical and molecular techniques was applied to a selection of 34 PCR-positive presumptive Aeromonas isolates. Following fatty acid methyl ester (FAME) analysis and amplified fragment length polymorphism (AFLP) fingerprinting, a total of 33 isolates (97%) could be identified to the DNA hybridization group (HG) level. The majority of these isolates belonged to the species Aeromonas hydrophila HG3 (50%) and Aeromonas veronii biovar sobria (HG8/10) (38%). Molecular characterization of PCR amplicons obtained from these strains by PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) fingerprinting and PCR-Amplicon Sequence Analysis (PCR-ASA) allowed classification of all strains in a known PCR-RFLP and PCR-ASA type. In conclusion, the current findings demonstrate that the combined use of PCR-based virulence marker detection, PCR-RFLP and PCR-ASA offers a rapid, sensitive, and specific system to assess the presence and prevalence of Aeromonas spp. harboring virulence markers in food samples. PMID:15193799

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

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    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.

  5. 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. PMID:26710336

  6. Chironomids' Relationship with Aeromonas Species.

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    Laviad, Sivan; Halpern, Malka

    2016-01-01

    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, and 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 6-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. PMID:27242751

  7. Isolation of drug-resistant Aeromonas hydrophila from aquatic environments.

    OpenAIRE

    McNicol, L A; Aziz, K. M.; Huq, I; Kaper, J B; Lockman, H A; Remmers, E F; Spira, W M; Voll, M. J.; Colwell, R R

    1980-01-01

    Antibiotic-resistant strains of Aeromonas hydrophila have been isolated from the natural environment in the Chesapeake Bay and areas surrounding Dacca and the Matlab region of Bangladesh. The Bangladesh strains carried resistance to chloramphenicol, streptomycin, and tetracycline, and 57% of them had a multiple streptomycin-tetracycline resistance phenotype correlated with the presence of a large plasmid. The Chesapeake Bay strains were resistant to polymyxin B ane tetracycline, but showed ne...

  8. 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...

  9. Aeromonas hydrophila surveillance 2010

    Science.gov (United States)

    In 2009, a virulent strain of Aeromonas hydrophila was associated with severly acute to chronic mortality in catfish ponds in Alabama. This strain of A. hydrophila had not been previously identified in AL catfish. The objectives of this presentation are to 1) present a summary of the biology of Aero...

  10. Chironomids’ Relationship with Aeromonas Species

    Science.gov (United States)

    Laviad, Sivan; Halpern, Malka

    2016-01-01

    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, and 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 6-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. PMID:27242751

  11. Draft Genome Sequence of Pseudomonas veronii Strain 1YdBTEX2

    Science.gov (United States)

    de Lima-Morales, Daiana; Chaves-Moreno, Diego; Jarek, Michael; Vilchez-Vargas, Ramiro; Jauregui, Ruy

    2013-01-01

    Pseudomonas veronii strain 1YdBTEX2 was isolated from a benzene-contaminated site. Here we report the draft genome sequence of 1YdBTEX2 and its genes associated with aromatic metabolism. The broad catabolic potential of this strain is consistent with the environment from which it was isolated. PMID:23682152

  12. The main Aeromonas pathogenic factors.

    Science.gov (United States)

    Tomás, J M

    2012-01-01

    The members of the Aeromonas genus are ubiquitous, water-borne bacteria. They have been isolated from marine waters, rivers, lakes, swamps, sediments, chlorine water, water distribution systems, drinking water and residual waters; different types of food, such as meat, fish, seafood, vegetables, and processed foods. Aeromonas strains are predominantly pathogenic to poikilothermic animals, and the mesophilic strains are emerging as important pathogens in humans, causing a variety of extraintestinal and systemic infections as well as gastrointestinal infections. The most commonly described disease caused by Aeromonas is the gastroenteritis; however, no adequate animal model is available to reproduce this illness caused by Aeromonas. The main pathogenic factors associated with Aeromonas are: surface polysaccharides (capsule, lipopolysaccharide, and glucan), S-layers, iron-binding systems, exotoxins and extracellular enzymes, secretion systems, fimbriae and other nonfilamentous adhesins, motility and flagella. PMID:23724321

  13. Resistensi Bakteri Aeromonas sp. Isolat Ikan Piranha (Pygosentrus nattereri Bali Safari And Marine Park terhadap Antibiotik

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    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. Aeromonas species in foods.

    Science.gov (United States)

    Isonhood, Jamie H; Drake, Maryanne

    2002-03-01

    Aeromonas species have been recognized as potential or emerging foodborne pathogens for more than 20 years. Aeromonads are estuarine bacteria and are ubiquitous in fresh water, fish and shellfish, meats, and fresh vegetables. Actual sourced foodborne outbreaks are few, but epidemiological evidence suggests that the bacterium can cause self-limiting diarrhea, with children being the most susceptible population. Most aeromonads are psychrotrophic and can grow in foods during cold storage. Aeromonads are not resistant to food processing regimes and are readily killed by heat treatment. A host of virulence factors are present, but the exact role of each in human disease has not been fully elucidated. PMID:11899061

  15. Detection and characterization of class 1 integrons in Aeromonas spp. isolated from human diarrheic stool in Mexico.

    Science.gov (United States)

    Pérez-Valdespino, Abigail; Fernández-Rendón, Elizabeth; Curiel-Quesada, Everardo

    2009-12-01

    We determined the presence of class 1 integrons related to the acquisition of resistance to antimicrobials in Aeromonas spp. isolated from individuals with diarrhea. Species were identified as A. caviae, A. hydrophila, A. veronii and A. media using PCR-RFLP of the 16S rDNA. Selected isolates were further characterized by ERIC-PCR. Resistance to chloramphenicol, aztreonam, tetracycline, trimethoprim/sulfamethoxazole, nalidixic acid and streptomycin, among others, was determined using the Kirby-Bauer method. Integrons were detected by PCR amplification of the 5' conserved, variable, and 3' conserved regions. Sequencing of the variable regions revealed class 1 integrons with cassettes encoding resistance to trimethoprim (dfrA12, dfrA15, dfrB4), streptomycin/spectinomycin (aadA2, aadA1), oxacillin (oxa2) and chloramphenicol (catB3, cmlA4). Others had an open reading frame (orfD) or no insert at all. To our knowledge, this is the first description of the occurrence of genes cmlA4 and dfrA15 in Aeromonas class 1 integrons. Not all the integron-linked cassettes conferred their associated resistances, which suggests the inactivity of some cassettes. Most integrons were chromosomally located. The presence of class 1 integrons similar to those found in a wide variety of bacterial genera from different origins, including environmental and fish-borne Aeromonas, confirms the stability and horizontal transfer of these genetic elements. PMID:19810047

  16. Biosynthesis of gold nanoparticles by Pseudomonas veronii AS41G inhabiting Annona squamosa L.

    Science.gov (United States)

    Baker, Syed; Satish, Sreedharamurthy

    2015-11-01

    Biogenic principles to nanotechnology have generated tremendous attention in recent past owing eco friendly benign process for synthesis of nanoparticles. Present investigation reports extracellular synthesis of gold nanoparticles using cell free supernatant of Pseudomonas veronii AS 41G, a novel endophyte isolated from Annona squamosa L. Gold nanoparticles formation was confirmed with UV-Visible spectrophotometer. FTIR analysis predicted various functional groups responsible for reduction of metal salts and stabilization of gold nanoparticles. Nanoparticles were crystalline in nature as shown in XRD pattern. TEM analysis revealed morphological characteristics of nanoparticles with different size. Thus the present study attributes for facile process for synthesis of gold nanoparticles as an alternative for conventional methods. The study also highlights the new role of novel bacterium Pseudomonas veronii AS41G which will be very valuable as a record for the researchers working on it. PMID:26093965

  17. Antimicrobial resistance in food and clinical Aeromonas isolates.

    Science.gov (United States)

    Palú, Angela Peres; Gomes, Luciana Martins; Miguel, Marco Antônio Lemos; Balassiano, Ilana Teruzkin; Queiroz, Mara Lucia Penna; Freitas-Almeida, Angela Corrêa; de Oliveira, Selma Soares

    2006-08-01

    This study highlights the incidence of resistance and the presence of plasmids in human and food isolates of Aeromonas in Brazil. A total of 83 Aeromonas spp. strains (28 isolated from human and 55 from fresh lettuce) were studied. Thirty-five were identified as A. hydrophila complex and 48 as A. caviae complex. All strains were shown to be susceptible to imipenem, amikacin, gentamicin, tobramycin and ciprofloxacin by the disk diffusion method. Resistance to antimicrobial agents was observed in strains of both food and clinical origin. The food strains were resistant to ampicillin/sulbactam, cefoxitin and tetracycline, while the clinical strains presented resistance to ampicillin/sulbactam, cefotaxime, ceftazidime, cefoxitin, sulfamethoxazole/trimethoprim, chloramphenicol and tetracycline. The minimal inhibitory concentrations of chloramphenicol, tetracycline and sulfamethoxazole/trimethoprim were tested by agar dilution. Thirteen strains isolated from vegetables were resistant to tetracycline (MIC 16 microg ml-1). Two A. hydrophila strains and one A. caviae strain presented extracromosomal DNA (3 and 15 kb plasmids, respectively). The tetracycline resistance phenotype determinant was related to the 15 kb plasmid according to cure and transformation experiments. PMID:16943044

  18. Potential pathogenicity of Aeromonas hydrophila complex strains isolated from clinical, food, and environmental sources.

    Science.gov (United States)

    Albarral, Vicenta; Sanglas, Ariadna; Palau, Montserrat; Miñana-Galbis, David; Fusté, M Carmen

    2016-04-01

    Aeromonas are autochthonous inhabitants of aquatic environments, including chlorinated and polluted waters, although they can also be isolated from a wide variety of environmental and clinical sources. They cause infections in vertebrates and invertebrates and are considered to be an emerging pathogen in humans, producing intestinal and extra-intestinal diseases. Most of the clinical isolates correspond to A. hydrophila, A. caviae, and A. veronii bv. Sobria, which are described as the causative agents of wound infections, septicaemia, and meningitis in immunocompromised people, and diarrhoea and dysenteric infections in the elderly and children. The pathogenic factors associated with Aeromonas are multifactorial and involve structural components, siderophores, quorum-sensing mechanisms, secretion systems, extracellular enzymes, and exotoxins. In this study, we analysed a representative number of clinical and environmental strains belonging to the A. hydrophila species complex to evaluate their potential pathogenicity. We thereby detected their enzymatic activities and antibiotic susceptibility pattern and the presence of virulence genes (aer, alt, ast, and ascV). The notably high prevalence of these virulence factors, even in environmental strains, indicated a potential pathogenic capacity. Additionally, we determined the adhesion capacity and cytopathic effects of this group of strains in Caco-2 cells. Most of the strains exhibited adherence and caused complete lysis. PMID:26889703

  19. Impact of an Urban Effluent on Antibiotic Resistance of Riverine Enterobacteriaceae and Aeromonas spp.

    Science.gov (United States)

    Goñi-Urriza, Marisol; Capdepuy, Michèle; Arpin, Corinne; Raymond, Nathalie; Caumette, Pierre; Quentin, Claudine

    2000-01-01

    In order to evaluate the impact of an urban effluent on antibiotic resistance of freshwater bacterial populations, water samples were collected from the Arga river (Spain), upstream and downstream from the wastewater discharge of the city of Pamplona. Strains of Enterobacteriaceae (representative of the human and animal commensal flora) (110 isolates) and Aeromonas (typically waterborne bacteria) (118 isolates) were selected for antibiotic susceptibility testing. Most of the Aeromonas strains (72%) and many of the Enterobacteriaceae (20%) were resistant to nalidixic acid. Singly nalidixic acid-resistant strains were frequent regardless of the sampling site for Aeromonas, whereas they were more common upstream from the discharge for enterobacteria. The most common resistances to antibiotics other than quinolones were to tetracycline (24.3%) and beta-lactams (20.5%) for Enterobacteriaceae and to tetracycline (27.5%) and co-trimoxazole (26.6%) for Aeromonas. The rates of these antibiotic resistances increased downstream from the discharge at similar degrees for the two bacterial groups; it remained at high levels for enterobacteria but decreased along the 30-km study zone for Aeromonas. Genetic analysis of representative strains demonstrated that these resistances were mostly (enterobacteria) or exclusively (Aeromonas) chromosomally mediated. Moreover, a reference strain of Aeromonas caviae (CIP 7616) could not be transformed with conjugative R plasmids of enterobacteria. Thus, the urban effluent resulted in an increase of the rates of resistance to antibiotics other than quinolones in the riverine bacterial populations, despite limited genetic exchanges between enterobacteria and Aeromonas. Quinolone resistance probably was selected by heavy antibiotic discharges of unknown origin upstream from the urban effluent. PMID:10618213

  20. CONTAMINATION RISK ASSESSMENT OF SOURCES OF WATER INTENDED FOR HUMAN CONSUMPTION WITH AEROMONAS SPP.

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    Luminita Minea

    2012-03-01

    Full Text Available mportance of Aeromonas spp as emerging pathogens in recent years has been a considerable increase, beingincluded by the World Health Organization (WHO and Environmental Protection Agency (EPA in the etiology ofwaterborne epidemics. We aimed to investigate the distribution of Aeromonas spp. in various aquatic ecosystems whichcan become potential sources of gastrointestinal infections. Simultaneously, the presence of this pathogen was evaluatedin relation to microbiological indicators set out in EU Directive 98/83/EC. Between March 2009 and May 2011 wereanalyzed by membrane filter technique untreated water samples, collected from surface sources (lakes, ponds andgroundwater (wells drilled, captured springs, wells and chlorinated water that coming from local distribution network,located in rural areas of Moldova (North-East Romania. The information was processed and interpreted statisticallyusing EpiInfo 3.5.1 software. The presence of Aeromonas spp. was detected in half of the 220 samples tested, especially,in surface waters (84% and captured springs (80.8% (χ 2=51.39; GL=4; p<0.001, with concentrations that ranged from1 to 3.8 x104CFU/100ml (median=4.9x103CFU/100ml, respectively, from 1 to 6.9x102CFU/100 ml (median =58CFU/100 ml . The main species identified were A. hydrophila (22%, A. caviae (10.2%, A. veronii (6% and A. sobria(6% (using API 20NE galeries. Although the etiology was reported in 15.9%, chlorinated water quality was much betterthan that of untreated sources (χ 2=26.56; GL=1; p<0.001, with Odd.Ratio =0.12 (0.04 to 0.31; CI=95%. Comparativeevaluation of contamination of studied ecosystems showed a higher presence of these organisms in surface water than ingroundwater (χ 2=8.71; GL=1; p<0.003, Odd.Ratio=37 (1.4 to 8.9; CI=95%, with an increased risk of infectiontransmission through ingestion or contact. Pearson coefficient for the presence in groundwater of fecal pollutionindicators (coliform bacteria, Escherichia coli, enterococci

  1. Detection of conjugation related type four secretion machinery in Aeromonas culicicola.

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    Ashraf Yusuf Rangrez

    Full Text Available BACKGROUND: Aeromonas sp. can now be considered relatively common enteropathogens due to the increase of diseases in humans. Aeromonas culicicola is a gram negative rod-shaped bacterium isolated for the first time from the mosquito mid-gut, but subsequently detected in other insects and waters also. Our previous study discovered that A. culicicola harbors three plasmids, which we designated as pAc3249A, pAc3249B and pAc3249C. We investigated and report here the existence and genetic organization of a Conjugal Type IV Secretion System (TFSS in pAc3249A. METHODOLOGY/PRINCIPLE FINDING: The complete operon is 11,061 bp in length and has G+C content of 47.20% code for 12 ORFs. The gene order and orientation were similar to those found in other bacteria with some differences. We have designated this system as AcTra for Aeromonas culicicola transfer system. BLAST results of ORFs and phylogenetic analysis showed significant similarity towards the respective proteins of the IncI2 plasmid R721 of E. coli. Other bioinformatics studies have been performed to predict conserved motifs/domains, signal peptides, transmembrane helices, etc. of the ORFs. CONCLUSIONS/SIGNIFICANCE: BLAST results of ORFs and phylogenetic analysis showed significant similarity towards the respective proteins of the IncI2 plasmid R721 of E. coli.

  2. Cystitis Caused by Aeromonas caviae▿

    OpenAIRE

    Al-Benwan, Khalifa; Abbott, Sharon; Janda, J. Michael; Huys, Geert; Albert, M. John

    2007-01-01

    Aeromonas sp. organisms rarely cause urinary tract infection. We report for the first time a case of urinary tract infection caused by A. caviae in an adult patient with a history of increased frequency of urination, dysuria, hematuria, and weight loss.

  3. Aeromonas spp. clinical microbiology and disease.

    Science.gov (United States)

    Parker, Jennifer L; Shaw, Jonathan G

    2011-02-01

    Members of the genus Aeromonas inhabit various aquatic environments and are responsible for, and are implicated in, a number of intestinal and extra-intestinal infections in humans as well as other animals. This review focuses on invasive human infection and disease and summarizes available findings regarding the microbiology and detection of Aeromonas spp., with emphasis on successful identification and diagnosis, and the control of disease in the population. Antimicrobial resistance and therapy of Aeromonas spp. is also discussed. PMID:21163298

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

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    M. Phani Kumar

    2013-06-01

    Full Text Available 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.

  5. Biochemical characteristics, serogroups, and virulence factors of aeromonas species isolated from cases of diarrhoea and domestic water samples in Chennai

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    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

  6. Correction: Structural Studies of the Lipopolysaccharide from the Fish Pathogen Aeromonas veronii Strain Bs19, Serotype O16. Mar. Drugs 2014, 12, 1298–1316

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    Anna Turska-Szewczuk

    2014-09-01

    Full Text Available We found one editorial mistake in our published paper [1]. In Line 2 of Table 4, the same composition of sugars is given for the C4 and C5 species (in the C5 species, one residue: 6dHexNAc has been missed. [...

  7. 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...

  8. 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...

  9. Identificação e resistência a antimicrobianos de espécies de Aeromonas móveis isoladas de peixes e ambientes aquáticos Identification and antimicrobial resistance of motile Aeromonas isolated from fish and aquatic environment

    Directory of Open Access Journals (Sweden)

    Daniela Hirsch

    2006-12-01

    Full Text Available Com o objetivo de se verificar a diversidade de espécies de Aeromonas móveis e seu perfil de susceptibilidade a antimicrobianos em pisciculturas comerciais, foram selecionadas oito tilapiculturas localizadas na região do Alto Rio Grande, Minas Gerais. De cada propriedade foram coletadas três amostras de peixes em estádio de pré-abate (vivos e saudáveis, uma amostra de água do tanque e uma amostra da água de abastecimento do sistema. De cada peixe foram coletadas amostras de lavado superficial e do parênquima renal. Diluições seriadas adequadas de cada amostra foram plaqueadas em TSA-ampicilina (10 mg/l e as amostras de rim em Ágar Sangue de cavalo a 5%. A partir de colônias isoladas positivas para o teste da oxidase foram realizados testes para identificação do gênero (testes presuntivos e das espécies de Aeromonas (testes bioquímicos. O perfil de antibiograma foi obtido pelo teste de difusão de discos de antibióticos em Ágar Mueller Hinton. Foram obtidos 75 isolados diferenciados em nove espécies de Aeromonas: A. jandaei, A. hydrophila, A. trota, A. caviae, A. sobria, A. eucrenophila, A. veronii bt veronii, A. schubertii, A. media, além de amostras classificadas como Aeromonas atípicas. Do total isolado, oito amostras foram provenientes da superfície corpórea de peixes, 14 da água de abastecimento e 53 da água do tanque. Não houve isolamento a partir dos espécimes de parênquima renal. Em relação ao perfil de resistência, 93% dos isolados foram resistentes à eritromicina, 36% à tetraciclina, 13% ao ác. nalidíxico, 9% à gentamicina, 8% à nitrofurantoína, 8% à canamicina, 5% à norfloxacina, 4% ao cloranfenicol e 3% às sulfonamidas. Dentre os isolados analisados, 43% apresentaram índice de múltipla resistência a antimicrobianos (MAR igual ou superior a 22%, ou seja, resistência a dois ou mais drogas das nove testadas. Os dados apontam para um risco iminente, tanto pelo isolamento de amostras

  10. 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.

  11. Aeromonas and Plesiomonas as food- and waterborne pathogens.

    Science.gov (United States)

    Wadström, T; Ljungh, A

    1991-04-01

    Aeromonas and Plesiomonas have become increasingly recognized as human enteropathogens. Plesiomonas shigelloides has mainly been recovered from various sea foods, whereas Aeromonas sp. have also been cultured from pigs, broilers, eggs, milk and vegetables. Aeromonas sp. also multiply rapidly at +4 degrees C which is a significant risk in food storage. Aeromonas sp. have furthermore been recovered from fresh water sources, and some isolates are resistant to chlorination which makes it a further risk factor. No large food- or waterborne outbreaks have been reported so far with Aeromonas sp. Various virulence factors involved in intestinal infections are described such as enterotoxins, cytotoxins, and adhesins. PMID:1854599

  12. Extracellular synthesis of silver nanoparticles by novel Pseudomonas veronii AS41G inhabiting Annona squamosa L. and their bactericidal activity

    Science.gov (United States)

    Baker, Syed; Mohan Kumar, K.; Santosh, P.; Rakshith, D.; Satish, S.

    2015-02-01

    In present investigation extracellular synthesis of silver nanoparticles were synthesized using cell free supernatant of Pseudomonas veronii AS41G isolated from Annona squamosa L. The bacterium significantly reduced silver nitrate to generate silver nanoparticles which was characterized with hyphenated techniques. Synthesis of silver nanoparticles preliminary confirmed by UV-Visible spectrophotometry with the intense peak at 410 nm, Further FTIR analysis revealed the possible role of biomolecules in the supernatant responsible for mediating the nanoparticles formation. The XRD spectra exhibited the characteristic Bragg peaks of 1 0 0, 1 1 1, 2 0 0, and 2 2 0 facets of the face centred cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. TEM microgram showed polydispersity of nanoparticles with size ranging from 5 to 50 nm. Synthesized silver nanoparticles showed antibacterial activity against human and environmental pathogens including MRSA. The study enlightens the role of biosynthesized silver nanoparticles as an emerging alternative for drug resistant microorganisms. The obtained results are promising enough to pave the environmentally benign nanoparticle synthesis processes without use of any toxic chemicals and also envision the emerging role of endophytes towards synthesis of nanoparticles. With scanty reports available on P.veronii species, a new role has been reported in this study which will be very valuable for future researchers working on it.

  13. 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.

  14. Development of an Aeromonas hydrophila recombinant extracellular protease vaccine.

    Science.gov (United States)

    Wu, Lei; Jiang, Ya-nan; Tang, Qian; Lin, Hui-xing; Lu, Cheng-ping; Yao, Huo-chun

    2012-01-01

    Aeromonas hydrophila (Ah) exists widely in the aquatic environment and infects a variety of animals. Extracellular protease (EPR) is an important protective antigen that induces a specific antibody response to resist Ah infection. In this study, two genes encoding extracellular protease epr2 and epr3 were linked within the expression vector pET32a to construct a recombinant pET-epr2-3 plasmid. The immunogenicity of the fusion protein epr2-3 was investigated as a subunit vaccine in ICR mice. The recombinant epr2-3 protein induced the production of high antibody titers. The survival rate against homogenous Ah J-1 challenge was significantly higher in the epr2-3 vaccinated group (≥80%) compared with the inactivated Ah vaccinated group and the challenge control group (P < 0.01), thus indicating that the recombinant epr2-3 protein provided significant protection against Ah infection. Therefore, the recombinant epr2-3 is a promising candidate for development as a vaccine against Ah infections. PMID:22874879

  15. AEROMONAS SPP. ASSOCIATED WITH COMMERCIAL POULTRY PROCESSING

    Science.gov (United States)

    Trials were conducted to examine the effect of commercial processing and refrigerated storage on Aeromonas bacteria in the native bacterial flora of broilers. The whole carcass rinse procedure was used to recover bacteria from prescalded, picked, prechilled, chilled, and refrigerated carcasses. Bact...

  16. Aeromonas spp.: An Emerging Nosocomial Pathogen.

    Science.gov (United States)

    Batra, Priyam; Mathur, Purva; Misra, Mahesh C

    2016-01-01

    Aeromonads are hallophillic, nonacid fast, nonspore forming, Gram-negative rods which are widely distributed in the soil, foodstuffs, and aquatic environment. Since times immemorial, they are important zoonotic pathogens of poikilotherms but are now emerging as important human pathogens. These emerging enteric pathogens flourish in the water distribution system by forming biofilms. They possess large number of virulence factors including inherent resistance to various antibiotics and ability to form biofilms using quorum sensing. These properties make them easy pathogens for human infections. Aeromonads are important enteric pathogens, but, with the growing level of immunosuppression in the population, they have been associated with various extraintestinal infections, such as skin and soft-tissue infections, traumatic wound infections, and lower respiratory tract/urinary tract infections. The average annual incidence of bacteremia in Southern Taiwan due to Aeromonas spp. was 76 cases/million inhabitants between 2008 and 2010. However, the incidence reported from Western countries is much lower. The case fatality rate among patients with Aeromonas bacteremia ranges from 27.5 to 46%. Aeromonads are universally resistant to the narrow-spectrum penicillin group of antibiotics such as penicillin, ampicillin, carbenicillin, and ticarcillin. They are however susceptible to piperacillin, azlocillin, second and third generation cephalosporins, and carbapenems. Most of the Aeromonas species are susceptible to aminoglycosides, tetracycline, chloramphenicol, trimethoprim-sulfamethoxazole, quinolones, and monobactams. This manuscript is a comprehensive systematic review of the literature available on Aeromonas spp. PMID:27013806

  17. Aeromonas spp.: An emerging nosocomial pathogen

    Directory of Open Access Journals (Sweden)

    Priyam Batra

    2016-01-01

    Full Text Available Aeromonads are hallophillic, nonacid fast, nonspore forming, Gram-negative rods which are widely distributed in the soil, foodstuffs, and aquatic environment. Since times immemorial, they are important zoonotic pathogens of poikilotherms but are now emerging as important human pathogens. These emerging enteric pathogens flourish in the water distribution system by forming biofilms. They possess large number of virulence factors including inherent resistance to various antibiotics and ability to form biofilms using quorum sensing. These properties make them easy pathogens for human infections. Aeromonads are important enteric pathogens, but, with the growing level of immunosuppression in the population, they have been associated with various extraintestinal infections, such as skin and soft-tissue infections, traumatic wound infections, and lower respiratory tract/urinary tract infections. The average annual incidence of bacteremia in Southern Taiwan due to Aeromonas spp. was 76 cases/million inhabitants between 2008 and 2010. However, the incidence reported from Western countries is much lower. The case fatality rate among patients with Aeromonas bacteremia ranges from 27.5 to 46%. Aeromonads are universally resistant to the narrow-spectrum penicillin group of antibiotics such as penicillin, ampicillin, carbenicillin, and ticarcillin. They are however susceptible to piperacillin, azlocillin, second and third generation cephalosporins, and carbapenems. Most of the Aeromonas species are susceptible to aminoglycosides, tetracycline, chloramphenicol, trimethoprim-sulfamethoxazole, quinolones, and monobactams. This manuscript is a comprehensive systematic review of the literature available on Aeromonas spp.

  18. Quorum Sensing Regulation in Aeromonas hydrophila

    DEFF Research Database (Denmark)

    Garde, Christian; Bjarnsholt, Thomas; Givskov, Michael; Jakobsen, Tim Holm; Hentzer, Morten; Claussen, Anetta; Sneppen, Kim; Ferkinghoff-Borg, Jesper; Sams, Thomas

    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.e., the...

  19. 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. ...

  20. Plasmid segregation mechanisms

    DEFF Research Database (Denmark)

    Ebersbach, Gitte; Gerdes, Kenn; Charbon, Gitte Ebersbach

    2005-01-01

    Bacterial plasmids encode partitioning (par) loci that ensure ordered plasmid segregation prior to cell division. par loci come in two types: those that encode actin-like ATPases and those that encode deviant Walker-type ATPases. ParM, the actin-like ATPase of plasmid R1, forms dynamic filaments...... that segregate plasmids paired at mid-cell to daughter cells. Like microtubules, ParM filaments exhibit dynamic instability (i.e., catastrophic decay) whose regulation is an important component of the DNA segregation process. The Walker box ParA ATPases are related to MinD and form highly dynamic, oscillating...... filaments that are required for the subcellular movement and positioning of plasmids. The role of the observed ATPase oscillation is not yet understood. However, we propose a simple model that couples plasmid segregation to ParA oscillation. The model is consistent with the observed movement...

  1. High Prevalence of Plasmid-Mediated Quinolone Resistance and IncQ Plasmids Carrying qnrS2 Gene in Bacteria from Rivers near Hospitals and Aquaculture in China.

    Science.gov (United States)

    Wen, Yanping; Pu, Xiaoying; Zheng, Wei; Hu, Guang

    2016-01-01

    Effluents from hospital and aquaculture are considered important sources of quinolone resistance. However, little information is available on the impact of this effluent on nearby rivers. In this study, 188 ciprofloxacin-resistant bacterial isolates obtained from rivers near hospitals and aquaculture were screened for plasmid-mediated quinolone resistance (PMQR) genes. Species identification, antibiotic susceptibility testing, and PMQR gene transferability assessment were conducted for PMQR-positive bacteria. Representative qnrS2-encoding plasmids were subsequently sequenced using a primer-walking approach. In total, 44 isolates (23.4%) were positive for qnr genes (16 qnrB2, 3 qnrS1, and 25 qnrS2) and 32 isolates (17.0%) were positive for aac(6')-Ib-cr. Other PMQR genes were not detected. The qnrB2 and aac(6')-Ib-cr genes had a higher prevalence in aquaculture samples than in hospital samples, and were significantly associated with Enterobacteriaceae (p < 0.05). In contrast, the prevalence of qnrS2 was not site-related, but was significantly associated with Aeromonas spp. (p < 0.05). All PMQR isolates were resistant to three or more classes of antibiotics. Eleven qnrS2-harboring plasmids from Aeromonas spp., including a novel conjugative plasmid pHP18, were selected for sequencing. These plasmids were small in size (6,388-16,197 bp) and belonged to the IncQ or IncU plasmid family, with qnrS2 being part of a mobile insertion cassette. Taken together, our findings suggest that aquaculture is a possible source for aac(6')-Ib-cr and qnrB2 dissemination, and demonstrate the ubiquity of qnrS2 in aquatic environments. Finally, Aeromonas spp. served as vectors for qnrS2 with the help of IncQ-type plasmids. PMID:27427763

  2. High Prevalence of Plasmid-Mediated Quinolone Resistance and IncQ Plasmids Carrying qnrS2 Gene in Bacteria from Rivers near Hospitals and Aquaculture in China.

    Directory of Open Access Journals (Sweden)

    Yanping Wen

    Full Text Available Effluents from hospital and aquaculture are considered important sources of quinolone resistance. However, little information is available on the impact of this effluent on nearby rivers. In this study, 188 ciprofloxacin-resistant bacterial isolates obtained from rivers near hospitals and aquaculture were screened for plasmid-mediated quinolone resistance (PMQR genes. Species identification, antibiotic susceptibility testing, and PMQR gene transferability assessment were conducted for PMQR-positive bacteria. Representative qnrS2-encoding plasmids were subsequently sequenced using a primer-walking approach. In total, 44 isolates (23.4% were positive for qnr genes (16 qnrB2, 3 qnrS1, and 25 qnrS2 and 32 isolates (17.0% were positive for aac(6'-Ib-cr. Other PMQR genes were not detected. The qnrB2 and aac(6'-Ib-cr genes had a higher prevalence in aquaculture samples than in hospital samples, and were significantly associated with Enterobacteriaceae (p < 0.05. In contrast, the prevalence of qnrS2 was not site-related, but was significantly associated with Aeromonas spp. (p < 0.05. All PMQR isolates were resistant to three or more classes of antibiotics. Eleven qnrS2-harboring plasmids from Aeromonas spp., including a novel conjugative plasmid pHP18, were selected for sequencing. These plasmids were small in size (6,388-16,197 bp and belonged to the IncQ or IncU plasmid family, with qnrS2 being part of a mobile insertion cassette. Taken together, our findings suggest that aquaculture is a possible source for aac(6'-Ib-cr and qnrB2 dissemination, and demonstrate the ubiquity of qnrS2 in aquatic environments. Finally, Aeromonas spp. served as vectors for qnrS2 with the help of IncQ-type plasmids.

  3. Aeromonas distribution and survival in a thermally altered lake

    International Nuclear Information System (INIS)

    Par Pond is a thermally enriched monomictic southeastern lake which receives heated effluent from a production nuclear reactor. Fish populations in the lake have lesions of epizooty from which Aeromonas spp. are readily isolated. Distribution and population densities of Aeromonas in the water column were measured along an oxygen and temperature gradient as well as seasonally. Greater population densities of Aeromonas occurred below the oxygen chemocline when the lake was stratified. Survival of Aeromonas hydrophila under in situ conditions in both epilimnetic and hypolimnetic waters was determined through the use of polycarbonate membrane diffusion chambers during two separate reactor operating conditions. Survival levels of pure cultures of A. hydrophila corresponded to the distribution patterns of the naturally occurring Aeromonas-like populations. The greater survival of A. hydrophila during full reactor operation suggests that the fish populations may be exposed to Aeromonas for a longer period of time than when the reactor is not operating

  4. Aeromonas aquariorum sp. nov., isolated from aquaria of ornamental fish.

    Science.gov (United States)

    Martínez-Murcia, A J; Saavedra, M J; Mota, V R; Maier, T; Stackebrandt, E; Cousin, S

    2008-05-01

    During a survey to determine the prevalence of Aeromonas strains in water and skin of imported ornamental fish, 48 strains presumptively identified as Aeromonas were isolated but they could not be identified as members of any previously described Aeromonas species. These strains were subjected to a polyphasic approach including phylogenetic analysis derived from gyrB, rpoD and 16S rRNA gene sequencing, DNA-DNA hybridization, MALDI-TOF MS analysis, genotyping by RAPD and extensive biochemical and antibiotic susceptibility tests in order to determine their taxonomic position. Based on the results of the phylogenetic analyses and DNA-DNA hybridization data, we describe a novel species of the genus Aeromonas, for which the name Aeromonas aquariorum sp. nov. is proposed, with strain MDC47T (=DSM 18362T =CECT 7289T) as the type strain. This is the first Aeromonas species description based on isolations from ornamental fish. PMID:18450708

  5. SPP1-mediated plasmid transduction.

    OpenAIRE

    Canosi, U; Lüder, G; Trautner, T A

    1982-01-01

    The virulent Bacillus subtilis phage SPP1 transduces plasmid DNA. Plasmid-transducing phages contain only plasmid DNA. Such DNA represents a concatemer of monomeric plasmid molecules with the molecular weight of mature SPP1 DNA. Biological parameters of plasmid transduction are described.

  6. 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. PMID:24370627

  7. Transfer in Marine Sediments of the Naturally Occurring Plasmid pRAS1 Encoding Multiple Antibiotic Resistance

    OpenAIRE

    Sandaa, Ruth-Anne; Enger, Øivind

    1994-01-01

    The results of microcosm experiments performed with the fish-pathogenic bacterium Aeromonas salmonicida acting as a donor showed that promiscuous plasmid pRAS1, which encodes tetracycline resistance, is transferred at a high frequency in marine sediments even in the absence of a selective factor. The presence of oxytetracycline resulted in an increase in the transfer frequency compared with that of a microcosm to which no selective factor was added. Transfer frequencies of 3.4 × 10-1 transcon...

  8. 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...

  9. 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...

  10. 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...

  11. Recurrent Aeromonas Bacteremia Due to Contaminated Well Water

    Science.gov (United States)

    Katz, Morgan J.; Parrish, Nicole M.; Belani, Anusha; Shah, Maunank

    2015-01-01

    Although they are ubiquitous to aquatic environments, Aeromonas species have traditionally been considered nonvirulent; however, in the past 30 years, they have emerged as important human pathogens that can cause a wide spectrum of disease. In this study, we describe a case of recurrent Aeromonas bacteremia in an immunocompetent patient, and this exposure was linked to the patient's home well water supply. PMID:26495324

  12. Antimicrobial resistance of Aeromonas hydrophila isolated from different food sources: A mini-review.

    Science.gov (United States)

    Stratev, Deyan; Odeyemi, Olumide A

    2016-01-01

    Aeromonas hydrophila is a Gram-negative, oxidase-positive, facultative, anaerobic, opportunistic aquatic pathogen. A. hydrophila produces virulence factors, such as hemolysins, aerolysins, adhesins, enterotoxins, phospholipase and lipase. In addition to isolation from aquatic sources, A. hydrophila has been isolated from meat and meat products, milk and dairy products, and vegetables. However, various studies showed that this opportunistic pathogen is resistant to commercial antibiotics. This is attributed to factors such as the indiscriminate use of antibiotics in aquaculture, plasmids or horizontal gene transfer. In this report, we highlight the occurrence, prevalence and antimicrobial resistance of A. hydrophila isolated from different food samples. The presence of antimicrobial-resistant A. hydrophila in food poses threats to public and aquatic animal health. PMID:26588876

  13. An alternative bacteriological medium for the isolation of Aeromonas spp.

    Science.gov (United States)

    Jenkins, J.A.; Taylor, P.W.

    1995-01-01

    Two solid bacteriologic media were compared for cultivating Aeromonas spp. from piscine sources: the Rimler-Shotts (RS) medium and a starch-glutamate-ampicillin-penicillin-based medium (SGAP-10C) used for the recovery of Aeromonas spp. from water samples. The selective and differential capacities of the media were assessed March through October 1992 by recovery rate and phenotype of 99 isolates representing 15 genera of bacteria. Recovery frequency of Aeromonas spp. (n = 62) was similar at 97% on RS and 95% on SGAP-10C. The SGAP-10C medium proved to be more specific than RS toward Aeromonas species (P ≤ 0.005). Use of SGAP-10C at 24 C for 48 hr offers a better choice for the laboratory recovery of Aeromonas spp. from clinical fish specimens.

  14. 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

  15. Molecular detection of enterotoxins in environmental strains of Aeromonas hydrophila and Aeromonas jandaei.

    Science.gov (United States)

    Balsalobre, L C; Dropa, M; Matté, G R; Matté, M H

    2009-12-01

    Aeromonas species are widely distributed in aquatic environments and recent studies include the genus in the emergent pathogens group because of its frequent association with local and systemic infections in immunocompetent humans. Aiming to search for virulence genes in environmental strains of Aeromonas hydrophila and Aeromonas jandaei, we designed specific primers to detect act/hlyA/aer complex and alt genes. Primers described elsewhere were used to detect ast. Eighty-seven strains previously identified using phenotypic and genotypic tests as A. hydrophila (41) and A. jandaei (46) were analysed for the presence of the virulence genes using PCR. DNA fragments of expected size were purified and directly sequenced. Among the 41 strains of A. hydrophila 70.7% (29), 97.6% (40) and 26.8% (11) possessed act/hlyA/aer complex, ast and alt genes, respectively. Among the 46 strains of A. jandaei, 4.4% (2), 0% (0) and 32.6% (15) were positive for act/hly A/aer complex, ast and alt genes, respectively. Sequencing allowed for the confirmation of amplified products using BLAST. The present work proposes a specific and rapid diagnostic method to detect the main virulence determinants of Aeromonas, a genus potentially pathogenic to humans. PMID:19590136

  16. 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. PMID:26577192

  17. 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...... 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...... new possibilities for salmonid aquaculture in terms of minimizing disease outbreaks and the use of antibiotics....

  18. fRNAdb Summary: FR291009 [

    Lifescience Database Archive (English)

    Full Text Available FR291009 AF198362,AF198367,AF198369,AF198370,AF198371,AF198372,AF198373,AF198375,AF198377,AF1983 ... mirabilis,Providencia stuartii,Edwardsiella tarda,Aeromonas ... salmonicida,Aeromonas ... punctata,Aeromonas ... veronii,V ... ibrio alginolyticus,Edwardsiella ictaluri,Aeromonas ... veronii bv. sobria,Photorhabdus luminescens subsp. ...

  19. fRNAdb Summary: FR217426 [

    Lifescience Database Archive (English)

    Full Text Available FR217426 AB003402,AB035920,AB035923,AB035926,AE005174,AE005674,AE008706,AE008886,AE008893,AE0167 ... igella boydii,Shigella flexneri,Edwardsiella tarda,Aeromonas ... hydrophila,Aeromonas ... punctata,Aeromonas ... veronii,Pr ... almonella enterica subsp. enterica serovar Newport,Aeromonas ... veronii bv. sobria,Salmonella enterica subsp. ente ...

  20. Plasmids encoding therapeutic agents

    Science.gov (United States)

    Keener, William K.

    2007-08-07

    Plasmids encoding anti-HIV and anti-anthrax therapeutic agents are disclosed. Plasmid pWKK-500 encodes a fusion protein containing DP178 as a targeting moiety, the ricin A chain, an HIV protease cleavable linker, and a truncated ricin B chain. N-terminal extensions of the fusion protein include the maltose binding protein and a Factor Xa protease site. C-terminal extensions include a hydrophobic linker, an L domain motif peptide, a KDEL ER retention signal, another Factor Xa protease site, an out-of-frame buforin II coding sequence, the lacZ.alpha. peptide, and a polyhistidine tag. More than twenty derivatives of plasmid pWKK-500 are described. Plasmids pWKK-700 and pWKK-800 are similar to pWKK-500 wherein the DP178-encoding sequence is substituted by RANTES- and SDF-1-encoding sequences, respectively. Plasmid pWKK-900 is similar to pWKK-500 wherein the HIV protease cleavable linker is substituted by a lethal factor (LF) peptide-cleavable linker.

  1. Salmonella Typhimurium ST213 is associated with two types of IncA/C plasmids carrying multiple resistance determinants

    Directory of Open Access Journals (Sweden)

    Zaidi Mussaret B

    2011-01-01

    Full Text Available Abstract Background Salmonella Typhimurium ST213 was first detected in the Mexican Typhimurium population in 2001. It is associated with a multi-drug resistance phenotype and a plasmid-borne blaCMY-2 gene conferring resistance to extended-spectrum cephalosporins. The objective of the current study was to examine the association between the ST213 genotype and blaCMY-2 plasmids. Results The blaCMY-2 gene was carried by an IncA/C plasmid. ST213 strains lacking the blaCMY-2 gene carried a different IncA/C plasmid. PCR analysis of seven DNA regions distributed throughout the plasmids showed that these IncA/C plasmids were related, but the presence and absence of DNA stretches produced two divergent types I and II. A class 1 integron (dfrA12, orfF and aadA2 was detected in most of the type I plasmids. Type I contained all the plasmids carrying the blaCMY-2 gene and a subset of plasmids lacking blaCMY-2. Type II included all of the remaining blaCMY-2-negative plasmids. A sequence comparison of the seven DNA regions showed that both types were closely related to IncA/C plasmids found in Escherichia, Salmonella, Yersinia, Photobacterium, Vibrio and Aeromonas. Analysis of our Typhimurium strains showed that the region containing the blaCMY-2 gene is inserted between traA and traC as a single copy, like in the E. coli plasmid pAR060302. The floR allele was identical to that of Newport pSN254, suggesting a mosaic pattern of ancestry with plasmids from other Salmonella serovars and E. coli. Only one of the tested strains was able to conjugate the IncA/C plasmid at very low frequencies (10-7 to 10-9. The lack of conjugation ability of our IncA/C plasmids agrees with the clonal dissemination trend suggested by the chromosomal backgrounds and plasmid pattern associations. Conclusions The ecological success of the newly emerging Typhimurium ST213 genotype in Mexico may be related to the carriage of IncA/C plasmids. We conclude that types I and II of Inc

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

    OpenAIRE

    Costa, F.N.; O.D. Rossi Júnior

    2002-01-01

    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 abastecim...

  3. Novel Plasmid-Encoded Class C β-Lactamase (MOX-2) in Klebsiella pneumoniae from Greece

    OpenAIRE

    Raskine, Laurent; Borrel, Isabelle; Barnaud, Guilène; Boyer, Sophie; Hanau-Berçot, Béatrice; Gravisse, Jérome; Labia, Roger; Arlet, Guillaume; Sanson-Le-Pors, Marie-José

    2002-01-01

    Klebsiella pneumoniae KOL, a clinical strain resistant to various β-lactams, was isolated from the stools of a patient from Greece. This strain harbored a new pI 9.1 plasmid-mediated AmpC β-lactamase with unusually high levels of hydrolytic activity for cefoxitin and cefotetan that we named MOX-2. Sequencing of blaMOX-2 revealed 93.2, 92.9, 92.7, and 73.1% identities with the deduced amino acid sequences of CMY-8, MOX-1, CMY-1, and the AmpC β-lactamase of Aeromonas sobria, respectively.

  4. Dynamics of Aeromonas species isolated from wastewater treatment system.

    Science.gov (United States)

    Martone-Rocha, S; Piveli, R P; Matté, G R; Dória, M C; Dropa, M; Morita, M; Peternella, F A; Matté, M H

    2010-12-01

    Aeromonas are widely distributed in the aquatic environment, and are considered to be emerging organisms that can produce a series of virulence factors. The present study was carried out in a sanitary sewage stabilization pond treatment system, located in Lins, State of São Paulo, Brazil. Most probable number was applied for estimation of the genus Aeromonas. Colony isolation was carried out on blood agar ampicillin and confirmed by biochemical characterization. Aeromonas species were isolated in 72.4% of influent samples, and in 55.2 and 48.3% of effluent from anaerobic and facultative lagoons, respectively. Thirteen Aeromonas species were isolated, representing most of the recognized species of these organisms. Even though it was possible to observe a tendency of decrease, total elimination of these organisms from the studied system was not achieved. Understanding of the pathogenic organism's dynamics in wastewater treatment systems with a reuse potential is especially important because of the risk it represents. PMID:20705981

  5. Hydrocarbon utilization by Brevibacterium, Azotomonas, Protaminobacterium, Mycococcus and Aeromonas spp

    Energy Technology Data Exchange (ETDEWEB)

    Lonsane, B.K.; Vadalkar, K.; Singh, H.D.; Baruah, J.N.

    1976-11-01

    Morphological, cultural and biochemical characteristics of 7 bacterial isolates, capable of utilizing hydrocarbons as sole source of carbon, reveal that 3 isolates belong to genus Aeromonas and one each to genera Brevibacterium, Protaminobacter, Mycococcus and Azotomonas. The isolates are studied for biomass formation on gas oil, substrate specificities for petroleum hydrocarbons and fermentation of gas oil by Brevibacterium sp. The hydrocarbon utilizing abilities of the strains of Protaminobacter, Azotomonas and Aeromonas are not known previously.

  6. Toxin plasmids of Clostridium perfringens.

    Science.gov (United States)

    Li, Jihong; Adams, Vicki; Bannam, Trudi L; Miyamoto, Kazuaki; Garcia, Jorge P; Uzal, Francisco A; Rood, Julian I; McClane, Bruce A

    2013-06-01

    In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ∼16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ∼45 kb to ∼140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ∼35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract. PMID:23699255

  7. 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...

  8. 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...

  9. Persistence Mechanisms of Conjugative Plasmids

    DEFF Research Database (Denmark)

    Bahl, Martin Iain; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    maintenance in the host cell. These importantly include the ability to self-mobilize in a process termed conjugative transfer, which may occur across species barriers. Other plasmid stabilizing mechanisms include the multimer resolution system, active partitioning, and post-segregational-killing of plasmid......Are plasmids selfish parasitic DNA molecules or an integrated part of the bacterial genome? This chapter reviews the current understanding of the persistence mechanisms of conjugative plasmids harbored by bacterial cells and populations. The diversity and intricacy of mechanisms affecting the...... successful propagation and long-term continued existence of these extra-chromosomal elements is extensive. Apart from the accessory genetic elements that may provide plasmid-harboring cells a selective advantage, special focus is placed on the mechanisms conjugative plasmids employ to ensure their stable...

  10. Quorum sensing regulation in Aeromonas hydrophila.

    Science.gov (United States)

    Garde, Christian; Bjarnsholt, Thomas; Givskov, Michael; Jakobsen, Tim Holm; Hentzer, Morten; Claussen, Anetta; Sneppen, Kim; Ferkinghoff-Borg, Jesper; Sams, Thomas

    2010-03-01

    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.e., the Escherichia coli monitor strain MH205), the C4-HSL production of A. hydrophila is interrupted by fusion of gfp(ASV). In the present in vitro study, we measure the response of the QS regulatory ahyRI locus in the monitor strain to predetermined concentrations of C4-HSL signal molecules. A minimal kinetic model describes the data well. It can be solved analytically, providing substantial insight into the QS mechanism: at high concentrations of signal molecules, a slow decay of the activated regulator sets the timescale for the QS regulation loop. Slow saturation ensures that, in an A. hydrophila cell, the QS system is activated only by signal molecules produced by other A. hydrophila cells. Separate information on the ahyR and ahyI loci can be extracted, thus allowing the probe to be used in identifying the target when testing QS inhibitors. PMID:20064524

  11. Aeromonas lusitana sp. nov., Isolated from Untreated Water and Vegetables.

    Science.gov (United States)

    Martínez-Murcia, Antonio; Beaz-Hidalgo, Roxana; Navarro, Aaron; Carvalho, M João; Aravena-Román, Max; Correia, Antonio; Figueras, M José; Saavedra, M José

    2016-06-01

    During previous studies to evaluate the phylogenetic diversity of Aeromonas from untreated waters and vegetables intended for human consumption, a group of isolates formed a unique gyrB phylogenetic cluster, separated from those of all other species described so far. A subsequent extensive phenotypic characterization, DNA-DNA hybridization, 16S rRNA gene sequencing, multi-locus phylogenetic analysis of the concatenated sequence of seven housekeeping genes (gyrB, rpoD, recA, dnaJ, gyrA, dnaX, and atpD; 4705 bp), and ERIC-PCR, were performed in an attempt to ascertain the taxonomy position of these isolates. This polyphasic approach confirmed that they belonged to a novel species of the genus Aeromonas, for which the name Aeromonas lusitana sp. nov. is proposed, with strain A.11/6(T) (=DSMZ 24095(T), =CECT 7828(T)) as the type strain. PMID:26868258

  12. In Silico Detection and Typing of Plasmids using PlasmidFinder and Plasmid Multilocus Sequence Typing

    DEFF Research Database (Denmark)

    Carattoli, Alessandra; Zankari, Ea; García-Fernández, Aurora; Larsen, Mette Voldby; Lund, Ole; Villa, Laura; Aarestrup, Frank Møller; Hasman, Henrik

    2014-01-01

    genomes of multidrug-resistant Enterobacteriaceae species by the rapid detection of known plasmid types. Replicon sequences from 559 fully sequenced plasmids associated with the family Enterobacteriaceae in the NCBI nucleotide database were collected to build a consensus database for integration into a...... plasmid sequence types (STs) and new alleles and ST variants. In conclusion, testing of the two Web tools using both fully assembled plasmid sequences and WGS-generated draft genomes showed them to be able to detect a broad variety of plasmids that are often associated with antimicrobial resistance in......In the work presented here, we designed and developed two easy-to-use Web tools for in silico detection and characterization of whole-genome sequence (WGS) and whole-plasmid sequence data from members of the family Enterobacteriaceae. These tools will facilitate bacterial typing based on draft...

  13. 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

  14. Conjugative plasmids of Neisseria gonorrhoeae.

    Directory of Open Access Journals (Sweden)

    Emilia Pachulec

    Full Text Available Many clinical isolates of the human pathogen Neisseria gonorrhoeae contain conjugative plasmids. The host range of these plasmids is limited to Neisseria species, but presence of a tetracycline (tetM determinant inserted in several of these plasmids is an important cause of the rapid spread of tetracycline resistance. Previously plasmids with different backbones (Dutch and American type backbones and with and without different tetM determinants (Dutch and American type tetM determinants have been identified. Within the isolates tested, all plasmids with American or Dutch type tetM determinants contained a Dutch type plasmid backbone. This demonstrated that tetM determinants should not be used to differentiate between conjugal plasmid backbones. The nucleotide sequences of conjugative plasmids with Dutch type plasmid backbones either not containing the tetM determinant (pEP5233 or containing Dutch (pEP5289 or American (pEP5050 type tetM determinants were determined. Analysis of the backbone sequences showed that they belong to a novel IncP1 subfamily divergent from the IncP1alpha, beta, gamma, delta and epsilon subfamilies. The tetM determinants were inserted in a genetic load region found in all these plasmids. Insertion was accompanied by the insertion of a gene with an unknown function, and rearrangement of a toxin/antitoxin gene cluster. The genetic load region contains two toxin/antitoxins of the Zeta/Epsilon toxin/antitoxin family previously only found in Gram positive organisms and the virulence associated protein D of the VapD/VapX toxin/antitoxin family. Remarkably, presence of VapX of pJD1, a small cryptic neisserial plasmid, in the acceptor strain strongly increased the conjugation efficiency, suggesting that it functions as an antitoxin for the conjugative plasmid. The presence of the toxin and antitoxin on different plasmids might explain why the host range of this IncP1 plasmid is limited to Neisseria species. The isolated plasmids

  15. [Bacteria of the genus Aeromonas and their role in aquaculture].

    Science.gov (United States)

    Kompanets, E V; Isaeva, N M; Balakhnin, I A

    1992-01-01

    Bacteria of genus Aeromonas are constant components of microbiota of fresh reservoirs where they, together with other microorganisms, play the part of natural biofilter and promote water self-purification. They are necessarily present in normal microflora of hydrobionts inhabiting fresh reservoirs. The greatest attention is paid by the researchers to Aeromonas and biotrophs in connection with epizootics in aquaculture which have become more frequent, in particular, under fish breeding. That is why the review is, to more extent, concerned in the works of this trend made by the foreign and home researchers for the last decade. PMID:1406386

  16. A plasmid in the archaebacterium Sulfolobus acidocaldarius

    OpenAIRE

    Yeats, Siobhán; McWilliam, Peter; Zillig, Wolfram

    1982-01-01

    A plasmid of mol. wt. ∼9 × 106 has been isolated from the archaebacterium Sulfolobus acidocaldarius strain B12. Plasmid production is induced by u.v. radiation. A copy of the plasmid is probably carried by the chromosome, integrated at a specific site. The entire plasmid, and also restriction fragments of it, has been cloned into Escherichia coli plasmid vectors, and the cleavage sites on the plasmid DNA of three restriction endonucleases have been mapped.

  17. Plasmid acquisition in microgravity

    Science.gov (United States)

    Juergensmeyer, Margaret A.; Juergensmeyer, Elizabeth A.; Guikema, James A.

    1995-01-01

    In microgravity, bacteria often show an increased resistance to antibiotics. Bacteria can develop resistance to an antibiotic after transformation, the acquisition of DNA, usually in the form of a plasmid containing a gene for resistance to one or more antibiotics. In order to study the capacity of bacteria to become resistant to antibiotics in microgravity, we have modified the standard protocol for transformation of Escherichia coli for use in the NASA-flight-certified hardware package, The Fluid Processing Apparatus (FPA). Here we report on the ability of E. coli to remain competent for long periods of time at temperatures that are readily available on the Space Shuttle, and present some preliminary flight results.

  18. Evolved plasmid-host interactions reduce plasmid interference cost.

    Science.gov (United States)

    Yano, Hirokazu; Wegrzyn, Katarznya; Loftie-Eaton, Wesley; Johnson, Jenny; Deckert, Gail E; Rogers, Linda M; Konieczny, Igor; Top, Eva M

    2016-09-01

    Antibiotic selection drives adaptation of antibiotic resistance plasmids to new bacterial hosts, but the molecular mechanisms are still poorly understood. We previously showed that a broad-host-range plasmid was poorly maintained in Shewanella oneidensis, but rapidly adapted through mutations in the replication initiation gene trfA1. Here we examined if these mutations reduced the fitness cost of TrfA1, and whether this was due to changes in interaction with the host's DNA helicase DnaB. The strains expressing evolved TrfA1 variants showed a higher growth rate than those expressing ancestral TrfA1. The evolved TrfA1 variants showed a lower affinity to the helicase than ancestral TrfA1 and were no longer able to activate the helicase at the oriV without host DnaA. Moreover, persistence of the ancestral plasmid was increased upon overexpression of DnaB. Finally, the evolved TrfA1 variants generated higher plasmid copy numbers than ancestral TrfA1. The findings suggest that ancestral plasmid instability can at least partly be explained by titration of DnaB by TrfA1. Thus under antibiotic selection resistance plasmids can adapt to a novel bacterial host through partial loss of function mutations that simultaneously increase plasmid copy number and decrease unfavorably high affinity to one of the hosts' essential proteins. PMID:27121483

  19. 库拉索芦荟提取物对维氏气单胞菌抑菌作用的研究%Study on the Bacteriostasis of Aloe Vera Extracts against Aeromonas veronii

    Institute of Scientific and Technical Information of China (English)

    杨永立; 王利; 吴满林

    2013-01-01

    采用榨汁法、水煮法和醇提法制备库拉索芦荟提取物,通过K-B法和二倍稀释法测定3种方法芦荟提取物对维氏气单胞菌的抑菌作用.结果显示,用3种方法制备的库拉索芦荟提取物对维氏气单胞菌均有不同程度的抑制作用,榨汁法、水煮法和醇提法得到的库拉索芦荟提取物对3株维氏气单胞菌的平均最小抑菌浓度(minimal inhibitory concentration,MIC)分别为l、0.5和0.125 g/mL,最小杀菌浓度(minimal bactericidal concentration,MBC)分别为1、1和0.25 g/mL.库拉索芦荟提取物对3株维氏气单胞菌均有抑制作用,芦荟提取物浓度越高抑菌效果越明显,其中醇提法的抑菌效率高,水煮法的抑菌作用其次,榨汁法的抑菌效果较弱.

  20. Aeromonas hydrophila septicaemia and muscle abscesses associated with immunosuppression.

    OpenAIRE

    Slevin, N J; Oppenheim, B A; Deakin, D. P.

    1988-01-01

    We report a case of septicaemia and muscle abscesses due to Aeromonas hydrophila. The patient was immunosuppressed due to Hodgkin's disease and treatment with cytotoxic chemotherapy. The abscesses resolved after prolonged antibiotic therapy. Organisms that were once considered rarely pathogenic are emerging as increasingly important in causing potentially lethal infections in immunosuppressed patients.

  1. Aeromonas hydrophila in 2010: Characteristics of Alabama outbreaks

    Science.gov (United States)

    For a second year, epidemics associated with a virulent strain of Aeromonas hydrophila resulted in losses of hundreds of thousands of pounds of market size Alabama (AL) catfish. During this period, the Alabama Fish Farming Center diagnosed outbreaks of this strain of A. hydrophila on 25% (28/113) o...

  2. 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 ...

  3. Aeromonas hydrophila: Observations of the Alabama industry in 2010

    Science.gov (United States)

    In 2009, the Alabama catfish industry experienced widespread mortality from infection by the bacterium Aeromonas hydrophila. As soon as pond water temperatures warmed above 26 degrees centigrade (80 degrees fahrenheit) in 2010, epidemics have again occurred across the industry. This talk, which is a...

  4. Characterization of atypical Aeromonas salmonicida by different methods

    DEFF Research Database (Denmark)

    Austin, B.; Austin, D.A.; Dalsgaard, Inger; Gudmundsdottir, B.K.; Høie, S.; Thornton, J.M.; Larsen, J.L.; O'Hici, B.; Powell, R.

    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. Ge...

  5. Characterization of atypical Aeromonas salmonicida by different methods

    DEFF Research Database (Denmark)

    Austin, B.; Austin, D.A.; Dalsgaard, Inger; Gudmundsdottir, B.K.; Høie, S.; Thornton, J.M.; Larsen, J.L.; O'Hici, B.; Powell, R.

    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. Ciprofloxacin-Resistant Aeromonas hydrophila Cellulitis following Leech Therapy

    OpenAIRE

    Giltner, Carmen L.; Bobenchik, April M; Uslan, Daniel Z.; Deville, Jaime G.; Humphries, Romney M.

    2013-01-01

    We report a case of surgical site infection with ciprofloxacin-resistant Aeromonas hydrophila following leech therapy. Antimicrobial and genetic analyses of leech and patient isolates demonstrated that the resistant isolates originated from the leech gut microbiota. These data suggest that ciprofloxacin monotherapy as a prophylaxis regimen prior to leech therapy may not be effective in preventing infection.

  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. PMID:22376235

  8. 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. PMID:23890674

  9. Detection of hemolytic strains of Aeromonas hydrophila and A . sobria along with other Aeromonas spp. from fish and fishery products by multiplex PCR.

    Science.gov (United States)

    Hussain, I A; Jeyasekaran, G; Shakila, R Jeya; Raj, K T; Jeevithan, E

    2014-02-01

    Hemolytic strains of Aeromonas spp. from fish and fishery products were detected by multiplex PCR. The selected primers for the amplification of segments of ahh1, asa1 and 16S rRNA gene yielded products with the size of 130 bp, 249 bp and 356 bp, respectively. This assay was found to be highly sensitive, as it could detect 7 and 9 cells of Aeromonas hydrophila and A. sobria with a detection limit of 1 pg of pure genomic DNA. The assay, when screened for 73 commercial fish and fishery product samples consisting of freshwater, marine fish and shellfish, showed 56 % positive for Aeromonas spp., 16 % for Aeromonas hydrophila and 13 % for A. sobria. This assay provides specific and reliable results and can be a powerful tool for the simultaneous detection of hemolytic strains of A. hydrophila A. sobria and other Aeromonas spp. from fish and fishery products. PMID:24493904

  10. Plasmid-mediated transformation in Bacillus megaterium.

    OpenAIRE

    Brown, B. J.; Carlton, B C

    1980-01-01

    A transformation system was developed for Bacillus megaterium by using antibiotic resistance plasmid deoxyribonucleic acid molecules derived from Staphylococcus aureus and Bacillus cereus. Lysozyme-generated protoplasts of B. megaterium allowed uptake of plasmid deoxyribonucleic acid in the presence of polyethylene glycol. Transformants expressed the antibiotic resistance determinants present on the plasmid deoxyribonucleic acid, and reisolated plasmid deoxyribonucleic acid yielded restrictio...

  11. Isolation of motile Aeromonas spp. from fish and their cytotoxic effect on Vero cell cultures

    OpenAIRE

    Karabasil Neđeljko; Ašanin Ružica; Baltić Milan Ž.; Teodorović V.; Dimitrijević Mirjana

    2002-01-01

    The presence of motile Aeromonas spp. in fish and other sea food on the Belgrade retail market was investigated with the aim of determining the ability of these bacteria to produce and secrete toxins. Nine strains of motile Aeromonas spp. were isolated from seventy-eight food samples. Aer. sobria was identified in three cases, while six of the obtained strains were identified as Aer. hydrophila. Strains of motile Aeromonas spp. from different sources were analyzed for cytotoxicity on Vero cel...

  12. Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates.

    OpenAIRE

    Burke, V.; J. Robinson; Gracey, M; Peterson, D.; Partridge, K

    1984-01-01

    The occurrence of Aeromonas spp. in the metropolitan water supply of Perth, Western Australia, Australia, was monitored at several sampling points during a period of 1 year. Water within the distribution system conformed to international standards for drinking water but contained Aeromonas spp. in numbers comparable to those in raw surface water, although this water was free of Escherichia coli. Coliforms and E. coli were found in raw surface waters, and Aeromonas spp. were found in raw water...

  13. Study on Outer Membrane Protein (OMP) Profile of Aeromonas Strains using SDS- PAGE

    OpenAIRE

    N Sachan; Agarwal, R.K.; Singh, V. P.

    2012-01-01

    Mesophilic aeromonads are being increasingly reported pathogen of humans and lower vertebrates. Water and foods are considered to be the chief source of Aeromonas spp. At present there are several techniques available for the detection of Aeromonas spp. from water and foods. However, there is still need to develop immunodiagnostics for rapid detection of Aeromonas spp. irrespective of their species or serotype. To meet out this requirement present study was undertaken to identify the common p...

  14. Study on Outer Membrane Protein (OMP Profile of Aeromonas Strains using SDS- PAGE

    Directory of Open Access Journals (Sweden)

    N Sachan

    2012-06-01

    Full Text Available Mesophilic aeromonads are being increasingly reported pathogen of humans and lower vertebrates. Water and foods are considered to be the chief source of Aeromonas spp. At present there are several techniques available for the detection of Aeromonas spp. from water and foods. However, there is still need to develop immunodiagnostics for rapid detection of Aeromonas spp. irrespective of their species or serotype. To meet out this requirement present study was undertaken to identify the common protein moiety in their OMPs by SDS-PAGE so, that immunoassays can be developed for efficient and rapid detection of Aeromonas spp. from foods. [Vet. World 2012; 5(3.000: 173-177

  15. Aeromonas spp. and microbial indicators in raw drinking water source Aeromonas sp. e indicadores microbiológicos em fontes de água não tratada

    OpenAIRE

    Marisa Di Bari; Hachich, Elayse M.; Adalgisa M.J. Melo; Sato, Maria I. Z.

    2007-01-01

    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 Aeromona...

  16. In vitro comparisons of the inhibitory activity of florfenicol copper sulfate and potassium permanganate towards Aeromonas hydrophila and Flavobacterium columnare

    Science.gov (United States)

    Aeromonas hydrophila and Flavobacterium columnare, the etiological agents of motile aeromonas septicemia (MAS) and columnaris disease, respectively, have been recently causing crippling moralities to the sunshine bass, Morone chrysops female X Morone saxatilis male (Percichthyidae), industry in the ...

  17. Producción de ácido indol-3-acético por Pseudomonas veronii R4 y formación de raíces en hojas de vid “Thompson seedless” in vitro

    Directory of Open Access Journals (Sweden)

    María F. Peñafiel-Jaramillo

    2016-06-01

    Full Text Available Rizobacterias con actividad antagonista son empleadas a problemas patológicos y promueven el desarrollo de tejido radicular de especies vegetales El objetivo del estudio fue evaluar la capacidad en síntesis de ácido indol-3-acetico (AIA y la formación de raíces en hojas de vid “Thompson Seedless”, por el empleo de Pseudomonas veronii R4 in vitro. La bacteria, fue incubada en medio mínimo M9 y se verificó la producción de AIA a 24, 48 y 72 h de muestreo, los sobrenadantes fueron analizandos por HPLC. Peciolos de hojas de “Thompson Seedless” fueron sumergidos por 5 min, en el tampón PBS con P. veronii R4 a (1.5 x 109 células mL-1, y evaluados a los 32 días post-inoculación. Los tratamientos fueron sujetos al análisis de varianza por DCA. Los sobrenadantes muestreados a 72 h, del cultivo de líquido con P. veronii R4, se obtuvo los mayores niveles de AIA entre 0.0231 a 0.0245 mM, al emplear 5 a 10 mM del precursor L-triptofano, del sobrenadante obtenido de P. fluorescens CHA0 la producción de AIA con 0.0174 mM a 10 mM de L-triptofano. Se obtuvo la regeneración del sistema radicular en los peciolos de hojas de “Thompson Seedless”, con un promedio de 14 raíces/planta bajo la aplicación de P. veronii R4. Estos resultados preliminares realzan la importancia de la cepa nativa P. veronii R4, que se estaría proyectando para futuras investigaciones de su empleo en condición de invernadero al desarrollo del sistema radicular en “Thompson Seedless”.

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

    OpenAIRE

    Damir Kapetanović; Emin Teskeredžić

    2004-01-01

    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 2...

  19. Multifocal Aeromonas Osteomyelitis in a Child with Leukemia

    OpenAIRE

    Doganis, Dimitrios; Baka, Margarita; Tsolia, Maria; Pourtsidis, Apostolos; Lebessi, Evangelia; Varvoutsi, Maria; Bouhoutsou, Despina; Kosmidis, Helen

    2016-01-01

    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 ...

  20. Multiplex PCR method for detection of three Aeromonas enterotoxin genes.

    Science.gov (United States)

    Kingombe, Cesar I Bin; D'Aoust, Jean-Yves; Huys, Geert; Hofmann, Lisa; Rao, Mary; Kwan, Judy

    2010-01-01

    A novel multiplex PCR method using three sets of specific primers was developed for the detection of the cytotoxic (act), heat-labile (alt), and heat-stable (ast) enterotoxin genes in Aeromonas spp. This assay was used to characterize 35 reference strains as well as 537 food-borne isolates. A total of seven gene pattern combinations were encountered, including act, alt, act/alt, act/alt/ast, act/alt/148-bp amplicon, alt/ast, and alt/148-bp amplicon. The alt gene was detected with 34 reference strains (97%) and occurred singly in 14% of these strains. The frequency of occurrence of the act/alt, act/alt/ast, and alt/ast gene patterns in reference strains was 14 (40%), 2 (6%), and 2 (6%), respectively. An unpredicted amplicon was detected in 11 reference strains (31%). Characterization of this amplicon showed that its size was 148 bp, as generated by the AHLF and AHLR primers, and that it uniquely aligned with the Aeromonas salmonicida A449 genome sequence (GenBank accession number CP000644). This amplicon was named Aeromonas salmonicida subsp. salmonicida hypothetical protein amplicon (AssHPA). In the 537 food-borne isolates, the act and alt genes were most dominant and were detected in 349 (65%) and 452 (84%) isolates, respectively, either alone or in combinations. The act and alt genes occurred singly in 30 (6%) and 128 (24%) of these strains, respectively. The act/alt gene pattern occurred in 315 isolates (59%), whereas the ast gene was always linked to strains exhibiting the act/alt/ast and alt/ast gene combinations in 4 (0.7%) and 5 (0.9%) isolates, respectively. The uniplex amplification of three enterotoxin genes separately confirms the specificity of the unique selected primers. This multiplex PCR is rapid and simple and can detect the presence of three Aeromonas enterotoxin genes in a single assay. PMID:19933350

  1. Endogenous Aeromonas Hydrophila Endophthalmitis in an Immunocompromised Patient

    OpenAIRE

    Sohn, Hee Jin; Nam, Dong Heun; Kim, Yeon Suk; Paik, Hae Jung

    2007-01-01

    Purpose To report a case of endogenous endophthalmitis due to Aeromonas hydrophila in a patient with distal common bile duct carcinoma and biliary sepsis. Methods A 72-year-old woman with distal common bile duct carcinoma, obstructive jaundice, diabetes mellitus, and hypertension had a 1-day history of blurred vision, redness, and eye discharges in the right eye. An ophthalmic examination showed no light perception vision, increased intraocular pressure, severe corneal edema, severe anterior ...

  2. Interactions between octopine and nopaline plasmids in Agrobacterium tumefaciens.

    OpenAIRE

    Hooykaas, P J; Den Dulk-Ras, H; Ooms, G.; Schilperoort, R.A.

    1980-01-01

    Transfer of octopine Ti plasmids to strains already carrying an octopine Ti plasmid was found to occur at the same (high) frequency as transfer to Ti plasmid lacking recipients, showing that resident Ti plasmids do not exhibit entry exclusion towards incoming Ti plasmids. The resident octopine Ti plasmid was lost by the recipient after the entrance of the incoming Ti plasmid, which is indicative of the incompatibility between the Ti plasmids. Octopine Ti plasmids were found to become establis...

  3. Effects of genes exerting growth inhibition and plasmid stability on plasmid maintenance.

    OpenAIRE

    Boe, L; Gerdes, K; Molin, S

    1987-01-01

    Plasmid stabilization mediated by the parA+ and parB+ genes of the R1 plasmid and the ccd+ and sop+ genes of the F plasmid was tested on a mini-R1 plasmid and a pBR322 plasmid derivative. The mini-R1 plasmid is thought to be unstably inherited owing to a low copy number and to random segregation of the plasmid at cell division, whereas cells harboring the pBR322 derivative used in this work are lost through competition with plasmid-free cells, mainly as a result of the shorter generation time...

  4. The route of antimicrobial resistance from the hospital effluent to the environment: focus on the occurrence of KPC-producing Aeromonas spp. and Enterobacteriaceae in sewage.

    Science.gov (United States)

    Picão, Renata C; Cardoso, Juliana P; Campana, Eloiza H; Nicoletti, Adriana G; Petrolini, Fernanda V B; Assis, Diego M; Juliano, Luiz; Gales, Ana C

    2013-05-01

    We investigated the antimicrobial resistance profile and the occurrence of Klebsiella pneumoniae carbapenemase (KPC)-producing Gram-negative rods in sewage samples obtained from a Brazilian teaching hospital and from the wastewater treatment plant (WWTP) that receives it for treatment. We identified multidrug-resistant bacteria as well as KPC-2-producing Aeromonas spp. and several Enterobacteriaceae species, including Kluyvera spp., in the hospital effluent and in different sites of the WWTP. Most isolates showed the blaKPC-2 gene harbored on a transposon that was carried by conjugative plasmids. The presence of KPC production among Aeromonas spp., Kluyvera spp., and other Enterobacteriaceae indicates the adaptability of such isolates to aquatic environments, not only in the hospital effluent but also throughout the WWTP. Although secondary treatment seems to decrease the amount of KPC producers in sewage, multidrug-resistant isolates are continually disposed in the urban river. Thus, sewage treatment regulations are urgently needed to decelerate the evolution of antimicrobial resistance beyond hospitals. PMID:23478032

  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. Comparative genomics of Aeromonas hydrophila isolates from an epidemic in channel catfish

    Science.gov (United States)

    Background Aeromonas hydrophila was identified as the etiologic agent infecting farmed channel catfish in 2009/2010, resulting in higher mortality rates than typical for motile Aeromonas septicemia with over 5 million pounds of catfish lost to this outbreak. The biochemistry, molecular phylogeny, an...

  7. 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

  8. Effect of copper sulfate on Aeromonas hydrophila infection in channel catfish (Ictalurus punctatus) fingerlings

    Science.gov (United States)

    Motile Aeromonad Septicemia (MAS) results from primary or secondary infection with bacteria from Gram(-) Aeromonas spp., including Aeromonas hydrophila. Since 2009, an emerging strain of A. hydrophila has been associated, as a primary pathogen, with significant morbidity and mortality in the U.S. c...

  9. Draft Genome Sequence of High-Melanin-Yielding Aeromonas media Strain WS

    OpenAIRE

    Chai, Baozhong; Wang, He; Chen, Xiangdong

    2012-01-01

    We sequenced the genome of the high-melanin-yielding Aeromonas media strain WS and then analyzed genes potentially involved in melanin formation. The 4.2-Mb draft genome carries multiple genes responsible for pyomelanin synthesis and other candidate genes identified in our separate study, which have no homolog in other strains of Aeromonas species.

  10. Whole-Genome Sequence of Aeromonas hydrophila Strain AH-1 (Serotype O11).

    Science.gov (United States)

    Forn-Cuní, Gabriel; Tomás, Juan M; Merino, Susana

    2016-01-01

    Aeromonas hydrophila is an emerging pathogen of aquatic and terrestrial animals, including humans. Here, we report the whole-genome sequence of the septicemic A. hydrophila AH-1 strain, belonging to the serotype O11, and the first mesophilic Aeromonas with surface layer (S-layer) to be sequenced. PMID:27587829

  11. 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

  12. 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. PMID:22806741

  13. Antiparallel plasmid-plasmid pairing may control P1 plasmid replication.

    OpenAIRE

    Abeles, A L; Austin, S J

    1991-01-01

    The copy number of the P1 plasmid replicon is stringently controlled, giving only one or two copies per newborn cell. Control is achieved by the action of the copy-control locus incA, which contains nine repeats of the 19-basepair binding site for the plasmid-encoded initiator protein RepA. A set of five similar repeats are present in the replication origin where RepA acts to trigger initiation. Using an in vitro replication system consisting of an Escherichia coli extract, the P1 origin as a...

  14. A plasmid in Legionella pneumophila.

    OpenAIRE

    Knudson, G B; Mikesell, P

    1980-01-01

    Sixteen strains from the six serogroups of Legionella pneumophila were examined for the presence of extrachromosomal genetic elements by a modified cleared lysate procedure, dye-buoyant centrifugation, and agarose gel electrophoresis. Two strains, Atlanta-1 and Atlanta-2 from serogroup II, each contained a plasmid of cryptic function with a molecular weight of ca. 30 megadaltons.

  15. Bacterial Plasmids in Antarctic Natural Microbial Assemblages

    OpenAIRE

    Kobori, Hiromi; Sullivan, Cornelius W.; Shizuya, Hiroaki

    1984-01-01

    Samples of psychrophilic and psychrotrophic bacteria were collected from sea ice, seawater, sediments, and benthic or ice-associated animals in McMurdo Sound, Antarctica. A total of 155 strains were isolated and tested for the presence of plasmids by DNA agarose gel electrophoresis. Thirty-one percent of the isolates carried at least one kind of plasmid. Bacterial isolates taken from sediments showed the highest plasmid incidence (42%), and isolates from seawater showed the lowest plasmid inc...

  16. Plasmid maintenance functions encoded on Dictyostelium discoideum nuclear plasmid Ddp1.

    OpenAIRE

    Hughes, J E; H. Kiyosawa; Welker, D L

    1994-01-01

    All of the plasmid-carried genes expressed during vegetative growth are essential for long-term maintenance of plasmid Ddp1 in the nucleus of Dictyostelium discoideum. Deletion of Ddp1 genes expressed only during development had no detectable effect on plasmid maintenance. Deletion of vegetatively expressed genes, either singly or in pairs, resulted in (i) a rapid loss of plasmid from cells grown in the absence of selection for plasmid retention, (ii) variation in the proportion of monomer to...

  17. Identification of Aeromonas hydrophila infection with specific monoclonal antibodies

    Directory of Open Access Journals (Sweden)

    Paisarn Sithigorngul

    2007-08-01

    Full Text Available Whole cell of Aeromonas hydrophila 1234 was used for immunization to produce monoclonal antibodies (MAbs. Three different groups of MAbs specific to Aeromonas were obtained. The first group of MAbs demonstrated high specificity and bound to the A. hydrophila 1234 only but did not bind to the other two A. hydrophila isolates. This group of MAbs bound to a series of lipo-polysaccharides (LPS with molecular masses range from 10 to190 kDa. The second group of antibodies recognized A. hydrophila 1234 and 2798 isolates, and bound to a series of LPS with molecular masses range from 5-200 kDa. The third group of MAbs recognized all three isolates of A. hydrophila and two isolates of A. sobria, and lightly bound to A. caviae. This group of MAbs also bound to an unknown protein with molecular mass of 20 kDa. The MAbs in group 1 and group 2 can be used to detect the bacteria in tissues by immunohistochemistry. Both groups of MAbs bound to LPS at different sites in which the MAbs in group 2 bound to the side chain of O antigen while the MAbs in group 1 bound to the polymerization site at the core of oligosaccharide. All of the MAbs can be used to identify Aeromonas by dot blotting with the sensitivity range from 103-104 CFU/l. This study demonstrated a convenient immunological tool that can be used for simple and accurate identification of A. hydrophila, as well as for diagnosis of the A. hydrophila infection in animals. This immunological tool can replace costly and laborious biochemical tests.

  18. Characterization of plasmids in Erwinia stewartii.

    OpenAIRE

    Coplin, D. L.; Rowan, R G; Chisholm, D A; Whitmoyer, R E

    1981-01-01

    Plasmids in 39 strains of Erwinia stewartii were examined by agarose gel electrophoresis. Most virulent strains had from 11 to 13 plasmids ranging in molecular mass from 2.8 to 210 megadaltons and contained plasmids of 210, 70, 49, 43, 29.5, 16.8, 8.8, and 2.8 megadaltons. Plasmids in strains SW2 and SS104 were characterized by both electron microscopy and agarose gel electrophoresis and may be useful as convenient references for sizing plasmids by electrophoresis. Specific size classes of pl...

  19. Multifocal Aeromonas Osteomyelitis in a Child with Leukemia.

    Science.gov (United States)

    Doganis, Dimitrios; Baka, Margarita; Tsolia, Maria; Pourtsidis, Apostolos; Lebessi, Evangelia; Varvoutsi, Maria; Bouhoutsou, Despina; Kosmidis, Helen

    2016-01-01

    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. PMID:27200197

  20. 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.

  1. 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.

  2. 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.

  3. ISOLATION AND GENOTYPING OF AEROMONAS SPP. IN READY-TO-EAT FOODS. PRELIMINARY RESULTS

    Directory of Open Access Journals (Sweden)

    F. Montemurro

    2011-08-01

    Full Text Available The taxonomy of the genus Aeromonas is constantly changing and it is important that strains are identified and carefully differentiate. The aim of this preliminary investigation was to assess the presence of Aeromonas spp. in RTE foods from supermarkets and sushi Take Away and stored at refrigeration temperature. Particular attention was given to the choice of culture media in order to assess their ability to differentiate Aeromonas spp. and to perform subsequent phylogenetic analysis and the characterization of the species isolated.

  4. Bactérias do gênero Aeromonas em abatedouro de frangos

    OpenAIRE

    Costa F.N.; Rossi Júnior O.D.

    2002-01-01

    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 abastecim...

  5. Isolation of motile Aeromonas spp. from fish and their cytotoxic effect on Vero cell cultures

    Directory of Open Access Journals (Sweden)

    Karabasil Neđeljko

    2002-01-01

    Full Text Available The presence of motile Aeromonas spp. in fish and other sea food on the Belgrade retail market was investigated with the aim of determining the ability of these bacteria to produce and secrete toxins. Nine strains of motile Aeromonas spp. were isolated from seventy-eight food samples. Aer. sobria was identified in three cases, while six of the obtained strains were identified as Aer. hydrophila. Strains of motile Aeromonas spp. from different sources were analyzed for cytotoxicity on Vero cell cultures. A cytotoxic effect was detected for all tested strains, but of different intensity.

  6. Virulence Plasmids of Spore-Forming Bacteria.

    Science.gov (United States)

    Adams, Vicki; Li, Jihong; Wisniewski, Jessica A; Uzal, Francisco A; Moore, Robert J; McClane, Bruce A; Rood, Julian I

    2014-12-01

    Plasmid-encoded virulence factors are important in the pathogenesis of diseases caused by spore-forming bacteria. Unlike many other bacteria, the most common virulence factors encoded by plasmids in Clostridium and Bacillus species are protein toxins. Clostridium perfringens causes several histotoxic and enterotoxin diseases in both humans and animals and produces a broad range of toxins, including many pore-forming toxins such as C. perfringens enterotoxin, epsilon-toxin, beta-toxin, and NetB. Genetic studies have led to the determination of the role of these toxins in disease pathogenesis. The genes for these toxins are generally carried on large conjugative plasmids that have common core replication, maintenance, and conjugation regions. There is considerable functional information available about the unique tcp conjugation locus carried by these plasmids, but less is known about plasmid maintenance. The latter is intriguing because many C. perfringens isolates stably maintain up to four different, but closely related, toxin plasmids. Toxin genes may also be plasmid-encoded in the neurotoxic clostridia. The tetanus toxin gene is located on a plasmid in Clostridium tetani, but the botulinum toxin genes may be chromosomal, plasmid-determined, or located on bacteriophages in Clostridium botulinum. In Bacillus anthracis it is well established that virulence is plasmid determined, with anthrax toxin genes located on pXO1 and capsule genes on a separate plasmid, pXO2. Orthologs of these plasmids are also found in other members of the Bacillus cereus group such as B. cereus and Bacillus thuringiensis. In B. thuringiensis these plasmids may carry genes encoding one or more insecticidal toxins. PMID:26104459

  7. Apolipoprotein A1 in channel catfish: Transcriptional analysis, antimicrobial activity, and efficacy as plasmid DNA immunostimulant against Aeromonas hydrophila infection

    Science.gov (United States)

    The objectives of this study were to: 1) determine transcriptional profiles of apolipoprotein A1 (ApoA1) in collected channel catfish tissues after infection with A. hydrophila by bath immersion; 2) investigate whether recombinant channel catfish apolipoprotein A1 produced in E. coli expression syst...

  8. 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...

  9. 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...

  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

    A survey was undertaken to examine sea water and sediment for the presence of Vibrio and Aeromonas spp. along approximately 900 km of coast in Southern Italy during early and late summer. A quantitative analysis was also done to evaluate the water fecal contamination at the stations examined. The...... results indicate that all the investigated areas were submitted to a wide spatial fluctuation of fecal contamination and that Vibrio and Aeromonas spp. were present in both high and low fecal-contaminated stations. Sixty two percent of the investigated samples were positive for Aeromonas spp., while 42......% 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 <10(2) cells 100 ml(-1). Thus, these findings support the hypothesis that the bacterial indicators (such as fecal...

  11. Fatal Aeromonas hydrophila Infection of Soft Tissue after Endoscopic Injection Sclerotherapy for Gastric Variceal Bleeding.

    Directory of Open Access Journals (Sweden)

    Ber-Ming Liu

    2004-10-01

    Full Text Available Aeromonas hydrophila, an anaerobic gram-negative bacillus, can cause severe infectionsin immune-compromised patients. We present a 45-year-old cirrhotic man who sufferedfrom hematemesis and received emergency endoscopic injection sclerotherapy (EISfor gastric variceal bleeding. Twenty-one hours after EIS, painful swelling of the bilaterallower extremities and fever occurred. Severe soft-tissue infections with emergence of hemorrhagicbullae over the bilateral lower extremities followed. Even under aggressive treatment,the patient died of overwhelming sepsis 42 hours after EIS. Cultures of the blood andserosanguineous fluid from the hemorrhagic bullae revealed Aeromonas hydrophila. To thebest of our knowledge, this is the first case of fatal Aeromonas hydrophila infection afteremergancy EIS for gastric variceal bleeding reported in the English literature. It is worthemphasizing that physicians should consider Aeromonas hydrophila infection in cirrhoticpatients who develop soft-tissue infections after variceal bleeding whether emergency EIShas been performed or not.

  12. Homemade Site Directed Mutagenesis of Whole Plasmids

    Science.gov (United States)

    Laible, Mark; Boonrod, Kajohn

    2009-01-01

    Site directed mutagenesis of whole plasmids is a simple way to create slightly different variations of an original plasmid. With this method the cloned target gene can be altered by substitution, deletion or insertion of a few bases directly into a plasmid. It works by simply amplifying the whole plasmid, in a non PCR-based thermocycling reaction. During the reaction mutagenic primers, carrying the desired mutation, are integrated into the newly synthesized plasmid. In this video tutorial we demonstrate an easy and cost effective way to introduce base substitutions into a plasmid. The protocol works with standard reagents and is independent from commercial kits, which often are very expensive. Applying this protocol can reduce the total cost of a reaction to an eighth of what it costs using some of the commercial kits. In this video we also comment on critical steps during the process and give detailed instructions on how to design the mutagenic primers. PMID:19488024

  13. Plasmid and chromosome partitioning: surprises from phylogeny

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Bugge Jensen, Rasmus

    2000-01-01

    Plasmids encode partitioning genes (par) that are required for faithful plasmid segregation at cell division. Initially, par loci were identified on plasmids, but more recently they were also found on bacterial chromosomes. We present here a phylogenetic analysis of par loci from plasmids...... and chromosomes from prokaryotic organisms. All known plasmid-encoded par loci specify three components: a cis-acting centromere-like site and two trans-acting proteins that form a nucleoprotein complex at the centromere (i.e. the partition complex). The proteins are encoded by two genes in an operon...... that is autoregulated by the par-encoded proteins. In all cases, the upstream gene encodes an ATPase that is essential for partitioning. Recent cytological analyses indicate that the ATPases function as adaptors between a host-encoded component and the partition complex and thereby tether plasmids and chromosomal...

  14. Uptake of plasmid deoxyribonucleic acid by Haemophilus.

    OpenAIRE

    Gromkova, R; Goodgal, S

    1981-01-01

    The uptake of circular and linear plasmid RSF0885 deoxyribonucleic acids, (DNAs) obtained from Haemophilus parainfluenzae 14, in both homologous and heterologous recipients was studied and compared with that of chromosomal DNA. High concentrations of divalent cations stimulated the uptake of either circular or linear plasmid DNA in H. parainfluenzae 14 competent cells but did not affect the uptake of chromosomal DNA. The biological activity of linear plasmid DNA was similar to that of circula...

  15. Genospecies and virulence factors of Aeromonas species in different sources in a North African country

    OpenAIRE

    Ahmed, Salwa F.; Cappuccinelli, Piero; Klena, John D.; Ghenghesh, Khalifa Sifaw

    2014-01-01

    Introduction: Aeromonads of medical importance have been reported from numerous clinical, food, and water sources, but identification of genospecies and virulence factors of Aeromonas species from countries in North Africa and the Middle East are few.Methods: In total 99 Aeromonas species isolates from different sources (diarrheal children [n=23], non-diarrheal children [n=16], untreated drinking water from wells [n=32], and chicken carcasses [n=28]) in Tripoli, Libya, were included in the pr...

  16. Extended-spectrum -lactamase and carbapenemase-producing Aeromonas species in wild animals from Portugal

    OpenAIRE

    Dias, C; Serra, C. R.; Simões, Lúcia C.; Simões, M.; Martinez-Murcia, A.; Saavedra, M.J.

    2014-01-01

    Aeromonas are Gram-negative, facultative-anaerobic, non-spore-forming, glucose-fermenting, oxidase- and catalase-positive rods (Martin-Carnahan and Joseph 2005). Apart from fish, which are widely reported hosts for Aeromonads, insects, crustaceans, reptiles, birds and mammals were also found to harbour Aeromonas species, both in healthy and disease state (Pearson and others 2000, Turutoglu and others 2005, Evangelista-Barreto and others 2006, Ceylan and others 2009). An increase in resistance...

  17. The Occurrence of Aeromonas in Drinking Water, Tap Water and the Porsuk River

    OpenAIRE

    Merih Kivanc; Meral Yilmaz; Filiz Demir

    2011-01-01

    The occurrence of Aeromonas spp. in the Porsuk River, public drinking water and tap water in the City of Eskisehir (Turkey) was monitored. Fresh water samples were collected from several sampling sites during a period of one year. Total 102 typical colonies of Aeromonas spp. were submitted to biochemical tests for species differentiation and of 60 isolates were confirmed by biochemical tests. Further identifications of isolates were carried out first with the VITEK system (BioMe˜rieux) and th...

  18. Impact of an Urban Effluent on Antibiotic Resistance of Riverine Enterobacteriaceae and Aeromonas spp.

    OpenAIRE

    Goñi-Urriza, Marisol; Capdepuy, Michèle; Arpin, Corinne; Raymond, Nathalie; Caumette, Pierre; Quentin, Claudine

    2000-01-01

    In order to evaluate the impact of an urban effluent on antibiotic resistance of freshwater bacterial populations, water samples were collected from the Arga river (Spain), upstream and downstream from the wastewater discharge of the city of Pamplona. Strains of Enterobacteriaceae (representative of the human and animal commensal flora) (110 isolates) and Aeromonas (typically waterborne bacteria) (118 isolates) were selected for antibiotic susceptibility testing. Most of the Aeromonas strains...

  19. Clonagem e expressão de uma potencial colagenase de Aeromonas hydrophila

    OpenAIRE

    Cavaleiro, Eliana Marisa dos Santos

    2008-01-01

    Aeromonas hydrophila é uma bactéria Gram-negativa que causa septicemia quer em peixes quer em humanos. Os principais patologias associados a infecções por Aeromonas são gastroenterites, infecção de feridas e doença sistémica. A patogenecidade deste organismo é multifactorial, possuindo factores na camada superficial proteica (camada S), diversos produtos extracelulares incluindo proteases, hemolisinas e enterotoxinas incluindo a acetilcolinesterase que contribui, significati...

  20. Molecular Detection, Quantification, and Toxigenicity Profiling of Aeromonas spp. in Source- and Drinking-Water.

    Science.gov (United States)

    Robertson, Boakai K; Harden, Carol; Selvaraju, Suresh B; Pradhan, Suman; Yadav, Jagjit S

    2014-01-01

    Aeromonas is ubiquitous in aquatic environments and has been associated with a number of extra-gastrointestinal and gastrointestinal illnesses. This warrants monitoring of raw and processed water sources for pathogenic and toxigenic species of this human pathogen. In this study, a total of 17 different water samples [9 raw and 8 treated samples including 4 basin water (partial sand filtration) and 4 finished water samples] were screened for Aeromonas using selective culturing and a genus-specific real-time quantitative PCR assay. The selective culturing yielded Aeromonas counts ranging 0 - 2 x 10(3)CFU/ml and 15 Aeromonas isolates from both raw and treated water samples. The qPCR analysis indicated presence of a considerable nonculturable population (3.4 x 10(1) - 2.4 x 10(4) cells/ml) of Aeromonas in drinking water samples. Virulence potential of the Aeromonas isolates was assessed by multiplex/singleplex PCR-based profiling of the hemolysin and enterotoxin genes viz cytotoxic heat-labile enterotoxin (act), heat-labile cytotonic enterotoxin (alt), heat-stable cytotonic enterotoxin (ast), and aerolysin (aerA) genes. The water isolates yielded five distinct toxigenicity profiles, viz. act, alt, act+alt, aerA+alt, and aerA+alt+act. The alt gene showed the highest frequency of occurrence (40%), followed by the aerA (20%), act (13%), and ast (0%) genes. Taken together, the study demonstrated the occurrence of a considerable population of nonculturable Aeromonads in water and prevalence of toxigenic Aeromonas spp. potentially pathogenic to humans. This emphasizes the importance of routine monitoring of both source and drinking water for this human pathogen and role of the developed molecular approaches in improving the Aeromonas monitoring scheme for water. PMID:24949108

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

    OpenAIRE

    Khor, Wei Ching; Puah, Suat Moi; Tan, Jin Ai Mary Anne; Puthucheary, SD; 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 Aer...

  2. pLS010 plasmid vector

    Science.gov (United States)

    Lacks, Sanford A.; Balganesh, Tanjore S.

    1988-01-01

    Disclosed is recombinant plasmid pLS101, consisting essentially of a 2.0 Kb malM gene fragment ligated to a 4.4 Kb T.sub.c r DNA fragment, which is particularly useful for transforming Gram-positive bacteria. This plasmid contains at least four restriction sites suitable for inserting exogeneous gene sequences. Also disclosed is a method for plasmid isolation by penicillin selection, as well as processes for enrichment of recombinant plasmids in Gram-positive bacterial systems.

  3. Chromate resistance plasmid in Pseudomonas fluorescens.

    OpenAIRE

    Bopp, L H; Chakrabarty, A M; Ehrlich, H. L.

    1983-01-01

    Chromate resistance of Pseudomonas fluorescens LB300, isolated from chromium-contaminated sediment in the upper Hudson River, was found to be plasmid specified. Loss of the plasmid (pLHB1) by spontaneous segregation or mitomycin C curing resulted in a simultaneous loss of chromate resistance. Subsequent transformation of such strains with purified pLHB1 plasmid DNA resulted in a simultaneous re-acquisition of the chromate resistance phenotype and the plasmid. When pLHB1 was transferred by con...

  4. ANALYSIS OF A MODEL OF PLASMID-BEARING, PLASMID-FREE COMPETITION IN A PULSED CHEMOSTAT

    OpenAIRE

    XIANGYUN SHI; XINYU SONG; XUEYONG ZHOU

    2006-01-01

    We introduce and study a chemostat model with plasmid-bearing, plasmid-free competition and impulsive effect. According to the stability analysis of the boundary periodic solution, we obtain the invasion threshold of the plasmid-free organism and plasmid-bearing organism. Furthermore, by using standard techniques of bifurcation theory, we prove the system has a positive τ-periodic solution, which shows that the impulsive effect destroys the equilibria of the unforced continuous system and ini...

  5. Prevalence and molecular characterization of Aeromonas spp. in ready-to-eat foods in Italy.

    Science.gov (United States)

    Villari, P; Crispino, M; Montuori, P; Stanzione, S

    2000-12-01

    A survey was carried out in Italy to ascertain the prevalence of Aeromonas spp. in ready-to-eat foods (vegetables, cheeses, meat products, and ice creams) and the level of molecular heterogeneity of the isolates found by macrorestriction analysis of genomic DNA with pulsed-field gel electrophoresis (PFGE). In total, 46 (14.4%) of the 320 food samples examined were found positive for Aeromonas spp. The highest percentages of isolation were discovered in vegetables, particularly lettuce (45.0%), endive (40.0%), and rucola (20.0%). Ricotta was the only cheese type analyzed that showed a high frequency of isolation (45.0%). Among meat products, salami and raw ham (25.0% of samples positive) and, to a lesser extent, baloney (5.0%) were found positive for Aeromonas spp. Aeromonas hydrophila was the most common isolate from foods of animal origin, whereas Aeromonas caviae was the dominant species in vegetables. No motile aeromonads were found in ice cream samples. Aeromonas isolates showed a high level of genetic heterogeneity, because 24 PFGE patterns were identified among 27 A. hydrophila strains and 20 PFGE patterns were found in 23 A. caviae isolates. In conclusion, consumers of ready-to-eat foods in Italy are regularly exposed to many genetically distinct strains of A. hydrophila and A. caviae without evident signs of malaise, and therefore, few of these strains, if any, are likely to be pathogenic. PMID:11131903

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

    OpenAIRE

    Praveen Kumar Praveen; Chanchal Debnath; Shashank Shekhar; Nirupama Dalai; Subha Ganguly

    2016-01-01

    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 competiti...

  7. Plasmid ColVBtrp maintenance in Erwinia carotovora.

    OpenAIRE

    Schukin, N N

    1981-01-01

    Plasmid ColVBtrp maintenance in Erwinia carotovora cells was followed by measuring kinetics of elimination of plasmid genetic markers and loss of plasmid deoxyribonucleic acid. An E. carotovora mutant stably carrying plasmid ColVBtrp was isolated. Besides stable plasmid maintenance, the mutant showed altered sensitivity to male-specific phage MS2, sensitivity to drugs, and colony morphology.

  8. The expression of a plasmid-specified exported protein causes structural plasmid instability in Bacillus subtilis

    NARCIS (Netherlands)

    Cordes, C.; Meima, R; Twiest, B; Kazemier, B; Venema, G; vanDijl, JM; Bron, S

    1996-01-01

    The rolling-circle plasmid pGP1 was used to study the effects of the expression of a plasmid-specified exported protein on structural plasmid stability in Bacillus subtilis. pGP1 contains a fusion between the Bacillus licheniformis penP gene, encoding a C-terminally truncated penicillinase, and the

  9. Decolorisation of Congo Red by Aeromonas hydrophila Under Microaerophilic Conditions

    International Nuclear Information System (INIS)

    Among 22 local bacterial isolates, Aeromonas hydrophila isolated from Bolti fish showed a remarkable ability to decolorize congo red under microaerophilic conditions (98.8% in 48 hrs) without prior adaptation. The bacterium had the ability to grow and decolorized high concentrations of congo red which varied from 50 to 1000 mg/l , the decolorisation was irrelevant to bacterial growth. The strain was capable of decolorizing congo red under a wide range of temperatures (20-40 degree C), ph (3-8), NaCl (0-200 mg/l) and also had the ability to decolorized mono, di and poly azo dyes. This bacterium is notable in its ability to decolorized the diazo congo red under extreme conditions of temperature, ph, salinity and high dye concentrations which makes it suitable for decolorisation under extreme industrial conditions

  10. Bacteremia due to Aeromonas hydrophila in Acute Lymphoblastic Leukemia

    International Nuclear Information System (INIS)

    Aeromonas hydrophila (A. hydrophila) is a low virulent organism but may cause devastating fatal infections in immunocompromised host especially in liver cirrhosis. It is rarely reported to cause septicemia in a patient with Acute Lymphoblastic Leukemia (ALL). The mortality rate of septicemia due to A. hydrophila is 29% to 73%. We report a case of 59-year-old female patient who was a known case of ALL, presented with the complaints of fever, lethargy and generalized weakness for one month. After taking blood samples for investigations, empirical antimicrobial therapy was started. She did not improve after 48 hours of therapy. Meanwhile blood culture revealed pure growth of A. hydrophila. After sensitivity report was available, ciprofloxacin was started. Patient became afebrile after 48 hours of treatment with ciprofloxacin. It is very vital to correctly identified and treat bacteremia due to A. hydrophila especially in the underlying leukemic patient. (author)

  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. BEHAVIOUR OF Aeromonas hydrophila IN SALTED SWORDFISH SAMPLES

    Directory of Open Access Journals (Sweden)

    G. Ziino

    2010-03-01

    Full Text Available A challenge test for Aeromonas hydrophila in salted swordfish samples was carried out. Particularly, 24 samples (250g were experimentally contaminated, salted and stored at two different temperature regimes (fluctuating – F group - and non fluctuating – NF group – regime. The count of A. hydrophila, Enterobacteria and Lactic acid bacteria (LAB as well as the determination of pH and aw were performed at 0, 19 43, 163, 187, 230, 320 and 368 hours whereas the temperature was monitored continuously by using 6 data-loggers. In both group, the mean concentrations of A. hydrophila did not exceed Log 3 cfu/g and decreased below the mean value of Log 1 cfu/g after 368 hours. However in the F group the A. hydrophila growth was slower and the decrease appeared slightly higher than NF group and this suggests the temperature fluctuations induces a more pronounced behaviour variability of A. hydrophila under stressing conditions.

  13. Comparação da sensibilidade de Danio rerio, Poecilia reticulata e Xiphophorus helleri a Aeromonas hydrophila e Aeromonas aquariorum

    OpenAIRE

    Chambel Martins, João

    2011-01-01

    Dissertação de Mestrado em Aquacultura apresentada à ESTM - Escola Superior de Turismo e Tecnologia do Mar do Instituto Politécnico de Leiria Este trabalho teve como objectivo comparar a sensibilidade de três das principais espécies de peixes ornamentais de água doce, Danio rerio, Poecilia reticulata e Xiphophorus helleri, a duas bactérias potencialmente zoonóticas para o Homem, Aeromonas hydprophila (SM 30016) e Aeromonas aquariorum (DSM 18362). De forma a efectuar a injecção intraperi...

  14. Evaluation of an in vitro cell assay to select attenuated bacterial mutants of Aeromonas hydrophila and Edwardsiella tarda to channel catfish

    Science.gov (United States)

    Both Aeromonas hydrophila (causative agent of motile aeromonas septicemia) and Edwardsiella tarda (causative agent of enteric septicemia) are Gram-negative bacteria widely distributed in aquatic environments, affecting many fish species worldwide, including channel catfish and tilapia. To control ba...

  15. Isolation of Plasmid DNA from Butyrivibrio fibrisolvens†

    OpenAIRE

    Teather, Ronald M.

    1982-01-01

    A procedure based on successive precipitation of cell lysates with sodium dodecyl sulfate-NaCl and polyethylene glycol 6000 was developed which allows the isolation of plasmid DNA from Butyrivibrio fibrisolvens. A survey of B. fibrisolvens strains isolated from the bovine rumen showed that plasmids are a common feature of this species.

  16. Plasmid deoxyribonucleic acid replication in Streptomyces griseus.

    OpenAIRE

    Xue, Y.; Zhuang, Z.; Zhu, Y.; Xu, Y.; Dong, K.

    1981-01-01

    A series of electron micrographs showing the presence of different molecular forms representing various replication stages of plasmid deoxyribonucleic acid from Streptomyces griseus was obtained. Based upon an analysis of these electron micrographs, a tentative model for plasmid deoxyribonucleic acid replication in S. griseus is proposed.

  17. Plasmid-mediated horizontal gene transfer is a coevolutionary process

    OpenAIRE

    Harrison, Ellie; Brockhurst, Michael A

    2012-01-01

    Conjugative plasmids are key agents of horizontal gene transfer (HGT) that accelerate bacterial adaptation by vectoring ecologically important traits between strains and species. However, although many conjugative plasmids carry beneficial traits, all plasmids exert physiological costs-of-carriage on bacteria. The existence of conjugative plasmids, therefore, presents a paradox because non-beneficial plasmids should be lost to purifying selection, whereas beneficial genes carried on plasmids ...

  18. fRNAdb Summary: FR138127 [

    Lifescience Database Archive (English)

    Full Text Available FR138127 AF198361,AF198363,AF198366,AF198374,AF198376,AF198379,AF407225,AF407231,AJ535850,AJ5358 ... 4 transfer RNA (tRNA), GAT (Ile/I) Isoleucine tRNA Aeromonas ... punctata,Aeromonas ... veronii,Photobacterium damselae ... piscicida,Photobacterium damselae subsp. damselae,Aeromonas ... veronii bv. sobria RF00005 Rfam v8.1 FR138127.jpg ...

  19. Bifurcation Analysis of a Chemostat Model of Plasmid-Bearing and Plasmid-Free Competition with Pulsed Input

    OpenAIRE

    Zhong Zhao; Baozhen Wang; Liuyong Pang; Ying Chen

    2014-01-01

    A chemostat model of plasmid-bearing and plasmid-free competition with pulsed input is proposed. The invasion threshold of the plasmid-bearing and plasmid-free organisms is obtained according to the stability of the boundary periodic solution. By use of standard techniques of bifurcation theory, the periodic oscillations in substrate, plasmid-bearing, and plasmid-free organisms are shown when some conditions are satisfied. Our results can be applied to control bioreactor aimed at producing co...

  20. Implication of lateral genetic transfer in the emergence of Aeromonas hydrophila isolates of epidemic outbreaks in channel catfish

    Science.gov (United States)

    Background: A recent epidemic outbreak of motile Aeromonas septicemia of catfish caused by highly virulent Aeromonas hydrophila is a major threat to the catfish industry in the southeastern United States. The lack of a complete genome sequence for this newly emerged A. hydrophila genotype hampers ef...

  1. 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.

  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. 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.

  4. Lateral flagella are required for increased cell adherence, invasion and biofilm formation by Aeromonas spp.

    Science.gov (United States)

    Gavín, Rosalina; Merino, Susana; Altarriba, Maria; Canals, Rocío; Shaw, Jonathan G; Tomás, Juan M

    2003-07-15

    Two types of flagella are responsible for motility in mesophilic Aeromonas strains. A polar unsheathed flagellum is expressed constitutively that allows the bacterium to swim in liquid environments and, in media where the polar flagellum is unable to propel the cell, Aeromonas express peritrichous lateral flagella. Recently, Southern blot analysis using a DNA probe based on the Aeromonas caviae Sch3N lateral flagellin gene sequence showed a good correlation between strains positive for the DNA probe, swarming motility and the presence of lateral flagella by microscopy. Here, we conclude that the easiest method for the detection of the lateral flagellin gene(s) is by PCR (polymerase chain reaction); this showed good correlation with swarming motility and the presence of lateral flagella. This was despite the high degree of DNA heterogeneity found in Aeromonas gene sequences. Furthermore, by reintroducing the laf (lateral flagella) genes into several mesophilic lateral-flagella-negative Aeromonas wild-type strains, we demonstrate that this surface structure enhances the adhesion to and invasion of HEp-2 cells and the capacity for biofilm formation in vitro. These results, together with previous data obtained using Laf- mutants, demonstrate that lateral flagella production is a pathogenic feature due to its enhancement of the interaction with eukaryotic cell surfaces. PMID:12855171

  5. Multiplex PCR detection of enterotoxin genes in Aeromonas spp. from suspect food samples in northern Taiwan.

    Science.gov (United States)

    Chang, Yu-Chang; Wang, Jan-Yi; Selvam, Ammaiyappan; Kao, Shu-Chen; Yang, Shang-Shyng; Shih, Daniel Yang-Chih

    2008-10-01

    Aeromonads possess an array of virulence factors and are causative agents of a number of human infections. Among them, genes of one cytotoxic (Act) and two cytotonic (Alt, Ast) enterotoxins are implicated in a human diarrheal disease. A rapid, specific, simultaneous detection of these enterotoxin genes in suspected food poisoning samples is not yet reported. Hence, a multiplex PCR assay was designed to amplify the cytotoxic (act), heat-labile cytotonic (alt), and heat-stable cytotonic (ast) enterotoxin genes of aeromonads. The PCR assay was tested with 133 Aeromonas spp. isolated from suspect food poisoning samples and retail samples of poultry and fish from wet markets in and around Taipei, Northern Taiwan. The Aeromonas spp. isolates were divided into six genotypes based on absence or presence of one or more enterotoxin genes. Of these 133 isolates, Aeromonas caviae (52.5%) and Aeromonas hydrophila (43.4%) were the most frequently isolated species from food poisoning samples and retail samples, respectively. Among the species, A. hydrophila had a significantly higher proportion for harboring three enterotoxin genes than had the others, whereas Aeromonas encheleia, considered a nonpathogen, was found harboring three enterotoxin genes. The multiplex PCR assays are rapid and specific, and provide a useful tool for the detection and genotyping of enterotoxin genes of aeromonads. PMID:18939759

  6. PcrA function in plasmid replication

    OpenAIRE

    Chisty, L. T.

    2014-01-01

    PcrA is a DNA helicase involved in unwinding plasmi ds as a part of a complex in asymmetric rolling - circle replication of certain plasmids carrying antibiotic resistance genes. PcrA translocates on single stranded DNA by coupling ATP hydrolysis to movement on DNA. Initiator protein, RepD is required to nick supercoiled plasmid site - specifically and open an ssDNA stretch that PcrA can bind. The presence of RepD is needed throughout plasmid unwinding to maintain processivity. Using fluo...

  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

    Directory of Open Access Journals (Sweden)

    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. Plasmids as Tools for Containment.

    Science.gov (United States)

    García, José L; Díaz, Eduardo

    2014-10-01

    Active containment systems are a major tool for reducing the uncertainty associated with the introduction of monocultures, genetically engineered or not, into target habitats for a large number of biotechnological applications (e.g., bioremediation, bioleaching, biopesticides, biofuels, biotransformations, live vaccines, etc.). While biological containment reduces the survival of the introduced organism outside the target habitat and/or upon completion of the projected task, gene containment strategies reduce the lateral spread of the key genetic determinants to indigenous microorganisms. In fundamental research, suicide circuits become relevant tools to address the role of gene transfer, mainly plasmid transfer, in evolution and how this transfer contributes to genome plasticity and to the rapid adaptation of microbial communities to environmental changes. Many lethal functions and regulatory circuits have been used and combined to design efficient containment systems. As many new genomes are being sequenced, novel lethal genes and regulatory elements are available, e.g., new toxin-antitoxin modules, and they could be used to increase further the current containment efficiencies and to expand containment to other organisms. Although the current containment systems can increase the predictability of genetically modified organisms in the environment, containment will never be absolute, due to the existence of mutations that lead to the appearance of surviving subpopulations. In this sense, orthogonal systems (xenobiology) appear to be the solution for setting a functional genetic firewall that will allow absolute containment of recombinant organisms. PMID:26104372

  9. Plasmid DNA fermentation strategies: influence on plasmid stability and cell physiology.

    Science.gov (United States)

    Silva, Filomena; Queiroz, João A; Domingues, Fernanda C

    2012-03-01

    In order to provide sufficient pharmaceutical-grade plasmid DNA material, it is essential to gain a comprehensive knowledge of the bioprocesses involved; so, the development of protocols and techniques that allow a fast monitoring of process performance is a valuable tool for bioprocess design. Regarding plasmid DNA production, the metabolic stress of the host strain as well as plasmid stability have been identified as two of the key parameters that greatly influence plasmid DNA yields. The present work describes the impact of batch and fed-batch fermentations using different C/N ratios and different feeding profiles on cell physiology and plasmid stability, investigating the potential of these two monitoring techniques as valuable tools for bioprocess development and design. The results obtained in batch fermentations showed that plasmid copy number values suffered a pronounced increase at the end of almost all fermentation conditions tested. Regarding fed-batch fermentations, the strategies with exponential feeding profiles, in contrast with those with constant feeding, showed higher biomass and plasmid yields, the maximum values obtained for these two parameters being 95.64 OD(600) and 344.3 mg plasmid DNA (pDNA)/L, respectively, when using an exponential feed rate of 0.2 h(-1). Despite the results obtained, cell physiology and plasmid stability monitoring revealed that, although higher pDNA overall yields were obtained, this fermentation exhibited lower plasmid stability and percentage of viable cells. In conclusion, this study allowed clarifying the bioprocess performance based on cell physiology and plasmid stability assessment, allowing improvement of the overall process and not only plasmid DNA yield and cell growth. PMID:22089386

  10. Enhancement of plasmid-mediated gene therapy for muscular dystrophy by directed plasmid integration

    OpenAIRE

    Bertoni, Carmen; Jarrahian, Sohail; Wheeler, Thurman M.; LI, YINING; Olivares, Eric C.; Michele P Calos; Rando, Thomas A.

    2005-01-01

    Plasmid-mediated gene therapy can restore dystrophin expression in skeletal muscle in the mdx mouse, a model of Duchenne muscular dystrophy. However, sufficient long-term expression and distribution of dystrophin remain a hurdle for translating this technology into a viable treatment for Duchenne muscular dystrophy. To improve plasmid-mediated gene therapy for muscle diseases, we studied the effects of targeted plasmid integration using a phage integrase (φC31) that can mediate the integratio...

  11. Virulence Factors of Aeromonas hydrophila: In the Wake of Reclassification.

    Science.gov (United States)

    Rasmussen-Ivey, Cody R; Figueras, Maria J; McGarey, Donald; Liles, Mark R

    2016-01-01

    The ubiquitous "jack-of-all-trades," Aeromonas hydrophila, is a freshwater, Gram-negative bacterial pathogen under revision in regard to its phylogenetic and functional affiliation with other aeromonads. While virulence factors are expectedly diverse across A. hydrophila strains and closely related species, our mechanistic knowledge of the vast majority of these factors is based on the molecular characterization of the strains A. hydrophila AH-3 and SSU, which were reclassified as A. piscicola AH-3 in 2009 and A. dhakensis SSU in 2013. Individually, these reclassifications raise important questions involving the applicability of previous research on A. hydrophila virulence mechanisms; however, this issue is exacerbated by a lack of genomic data on other research strains. Collectively, these changes represent a fundamental gap in the literature on A. hydrophila and confirm the necessity of biochemical, molecular, and morphological techniques in the classification of research strains that are used as a foundation for future research. This review revisits what is known about virulence in A. hydrophila and the feasibility of using comparative genomics in light of this phylogenetic revision. Conflicting data between virulence factors, secretion systems, quorum sensing, and their effect on A. hydrophila pathogenicity appears to be an artifact of inappropriate taxonomic comparisons and/or be due to the fact that these properties are strain-specific. This review audits emerging data on dominant virulence factors that are present in both A. dhakensis and A. hydrophila in order to synthesize existing data with the aim of locating where future research is needed. PMID:27610107

  12. Isolation and characterization of motile Aeromonas from human, food and environmental specimens.

    Science.gov (United States)

    Nishikawa, Y; Kishi, T

    1988-10-01

    From July 1985 to March 1987, the occurrence of motile Aeromonas sp. in stool, food and environmental specimens was investigated to assess their pathogenic significance and to determine sources and routes of infection. A total of 9366 stool specimens were examined; Aeromonas was isolated from 11.1% of diarrhoeal stools and 2.2% of normal stools (P less than 0.001). Aeromonas counts in food specimens, which included minced beef, pork and chicken, seafood and various vegetables and their products, were unexpectedly high suggesting that infection might be food-borne rather than water-borne. About 70% of the isolates from meat products were A. hydrophila and A. sobria, while A. caviae was the most common in sea-fish, vegetables and their products. Most A. hydrophila and A. sobria strains produced haemolysin, but haemagglutinin was found more frequently in A. sobria. PMID:3181307

  13. 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.; Pasquale, V.; Baloda, Suraj B.; Figliuolo, G.

    2000-01-01

    coliforms) do not always satisfactorily reflect the hygienic quality of water. The presence of Vibrionaceae on copepods was also investigated. Copepods were sampled at a station located inside the harbour of the city of Naples and were found contaminated by V. cholerae non-Ol, V. alginolyticus, V. fluvialis......A survey was undertaken to examine sea water and sediment for the presence of Vibrio and Aeromonas spp. along approximately 900 km of coast in Southern Italy during early and late summer. A quantitative analysis was also done to evaluate the water fecal contamination at the stations examined. The...... results indicate that all the investigated areas were submitted to a wide spatial fluctuation of fecal contamination and that Vibrio and Aeromonas spp. were present in both high and low fecal-contaminated stations. Sixty two percent of the investigated samples were positive for Aeromonas spp., while 42...

  14. Elimination of multicopy plasmid R6K by bleomycin.

    OpenAIRE

    Attfield, P V; Pinney, R. J.

    1985-01-01

    Bleomycin eliminated multicopy plasmid R6K from growing cells of Escherichia coli AB1157 but failed to cure either of the low-copy plasmids R1 or R46. Measurements of R6K-encoded beta-lactamase and of covalently closed plasmid DNA indicated that the drug causes a progressive reduction in plasmid copy number.

  15. Behavior of IncQ Plasmids in Agrobacterium tumefaciens

    NARCIS (Netherlands)

    Hille, Jacques; Schilperoort, Rob

    1981-01-01

    Inc-Q plasmids were introduced into Agrobacterium tumefuciens, by mobilization from Escherichia coli with an Inc-P plasmid, or by transformation with purified plasmid DNA. It was found that they were stably maintained. The presence of an Inc-Q plasmid did not influence tumorigenicity. These results

  16. Curing of plasmid pXO1 from Bacillus anthracis using plasmid incompatibility.

    Directory of Open Access Journals (Sweden)

    Xiankai Liu

    Full Text Available The large plasmid pXO1 encoding the anthrax toxin is important for the virulence of Bacillus anthracis. It is essential to cure pXO1 from B. anthracis to evaluate its role in the pathogenesis of anthrax infection. Because conventional methods for curing plasmids (e.g., curing agents or growth at elevated temperatures can induce mutations in the host chromosomal DNA, we developed a specific and reliable method to eliminate pXO1 from B. anthracis using plasmid incompatibility. Three putative replication origins of pXO1 were inserted into a temperature-sensitive plasmid to generate three incompatible plasmids. One of the three plasmids successfully eliminated the large plasmid pXO1 from B. anthracis vaccine strain A16R and wild type strain A16. These findings provided additional information about the replication/partitioning of pXO1 and demonstrated that introducing a small incompatible plasmid can generate plasmid-cured strains of B. anthracis without inducing spontaneous mutations in the host chromosome.

  17. Positive epistasis between co-infecting plasmids promotes plasmid survival in bacterial populations

    OpenAIRE

    San Millan, Alvaro; Heilbron, Karl; MacLean, R. Craig

    2014-01-01

    Plasmids have a key role in the horizontal transfer of genes among bacteria. Although plasmids are catalysts for bacterial evolution, it is challenging to understand how they can persist in bacterial populations over the long term because of the burden they impose on their hosts (the ‘plasmid paradox'). This paradox is especially perplexing in the case of ‘small' plasmids, which are unable to self-transfer by conjugation. Here, for the first time, we investigate how interactions between co-in...

  18. Mini-F plasmid genes that couple host cell division to plasmid proliferation.

    OpenAIRE

    Ogura, T; Hiraga, S

    1983-01-01

    A mechanism for stable maintenance of plasmids, besides the replication and partition mechanisms, has been found to be specified by genes of a mini-F plasmid. An oriC plasmid carrying both a mini-F segment necessary for partition [coordinates 46.4-49.4 kilobase pairs (kb) on the F map] and another segment (42.9-43.6 kb), designated ccd (coupled cell division), is more stably maintained than are oriC plasmids carrying only the partition segment; the stability is comparable to that of the paren...

  19. Adaptive Plasmid Evolution Results in Host-Range Expansion of a Broad-Host-Range Plasmid

    OpenAIRE

    De Gelder, Leen; Williams, Julia J.; Ponciano, José M; Sota, Masahiro; Eva M. Top

    2008-01-01

    Little is known about the range of hosts in which broad-host-range (BHR) plasmids can persist in the absence of selection for plasmid-encoded traits, and whether this “long-term host range” can evolve over time. Previously, the BHR multidrug resistance plasmid pB10 was shown to be highly unstable in Stenotrophomonas maltophilia P21 and Pseudomonas putida H2. To investigate whether this plasmid can adapt to such unfavorable hosts, we performed evolution experiments wherein pB10 was maintained ...

  20. Characterization of a Haemophilus ducreyi mobilizing plasmid.

    OpenAIRE

    McNicol, P J; Albritton, W L; Ronald, A R

    1986-01-01

    The OriV site of Haemophilus ducreyi mobilizing plasmid pHD147, determined by replication in Escherichia coli polA, is located close to the OriT site. The OriT site, located by recombination-proficient and -deficient cells, and the OriV site map in a region of pHD147 homologous to the beta-lactamase-specifying plasmids of H. ducreyi and Neisseria gonorrhoeae.

  1. Plasmid and chromosome segregation in prokaryotes

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Bugge Jensen, Rasmus; Gerdes, Kenn

    2000-01-01

    Recent major advances in the understanding of prokaryotic DNA segregation have been achieved by using fluorescence microscopy to visualize the localization of cellular components. Plasmids and bacterial chromosomes are partitioned in a highly dynamic fashion, suggesting the presence of a mitotic......-like apparatus in prokaryotes. The identification of chromosomal homologues of the well-characterized plasmid partitioning genes indicates that there could be a general mechanism of bacterial DNA partitioning. Udgivelsesdato: July 1...

  2. Sensitivity of planktonic and biofilm-associated Aeromonas spp. to ionizing radiation

    International Nuclear Information System (INIS)

    Genus Aeromonas has emerged as an important human pathogen because it causes a variety of diseases including gastroenteritis and extra-intestinal infections. Aeromonas have the ability to adhere and form biofilms on food surfaces and food contact surfaces. Biofilm formation on foods and food contact surfaces is the major reason for contamination, cross contamination and post-processing contamination of the final food product leading to food spoilage, product rejection, economic losses and food-borne diseases. Biofilms have shown high resistance to heat, desiccation, acidic condition, high salt concentration, antibiotics and other food preservatives. Earlier studies in our laboratory have shown that ionizing radiation effectively inactivates Aeromonas in different food products. However, the relative efficacy of this process against biofilm associated cells versus free-living planktonic cells of Aeromonas is not well documented. Therefore, the dose of gamma radiation required to reduce the population by 90% (D10) was calculated for planktonic and biofilm-associated A. salmonicida Y567 and A. hydrophila A331 cells. Both A. hydrophila A331 and A. salmonicida Y567 expressed significant ability to attach and grow on glass surface following incubation at 30℃ in TSB. Ionizing radiation effectively reduced the populations of both planktonic and biofilm-associated cells for both the strains. Mean cell counts of survivors and surviving fraction of planktonic and biofilm-associated cells decreased with increased irradiation doses. The D10 values of planktonic cells and biofilm cells for A. salmonicida (Y567) were 232.65 Gy and 248.41 Gy, respectively; whereas, the D10 values of planktonic cells and biofilm cells for A. hydrophila (A331) were 249.2 Gy and 240.2 Gy respectively. No significant difference in the D10 values of planktonic and biofilm associated Aeromonas was observed. The influence of the cultured state of the organism, i.e., planktonic versus biofilm associated

  3. Plasmid Evolution and Interaction between the Plasmid Addiction Stability Systems of Two Related Broad-Host-Range IncQ-Like Plasmids

    OpenAIRE

    Deane, Shelly M.; Rawlings, Douglas E

    2004-01-01

    Plasmid pTC-F14 contains a plasmid stability system called pas (plasmid addiction system), which consists of two proteins, a PasA antitoxin and a PasB toxin. This system is closely related to the pas of plasmid pTF-FC2 (81 and 72% amino acid identity for PasA and PasB, respectively) except that the pas of pTF-FC2 contains a third protein, PasC. As both pTC-F14 and pTF-FC2 are highly promiscuous broad-host-range plasmids isolated from bacteria that share a similar ecological niche, the plasmid...

  4. Cloning, mutagenesis, and nucleotide sequence of a siderophore biosynthetic gene (amoA) from Aeromonas hydrophila.

    OpenAIRE

    Barghouthi, S; Payne, S M; Arceneaux, J E; Byers, B R

    1991-01-01

    Many isolates of the Aeromonas species produce amonabactin, a phenolate siderophore containing 2,3-dihydroxybenzoic acid (2,3-DHB). An amonabactin biosynthetic gene (amoA) was identified (in a Sau3A1 gene library of Aeromonas hydrophila 495A2 chromosomal DNA) by its complementation of the requirement of Escherichia coli SAB11 for exogenous 2,3-DHB to support siderophore (enterobactin) synthesis. The gene amoA was subcloned as a SalI-HindIII 3.4-kb DNA fragment into pSUP202, and the complete n...

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

    DEFF Research Database (Denmark)

    Dalsgaard, Inger; Gudmundsdottir, B.K.; Helgason, S.; Høie, S.; Thoresen, O.F.; Wichardt, U.P.; Wiklund, T.

    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 the...

  6. Relationship between plasmid content and auxotype in Neisseria gonorrhoeae isolates.

    OpenAIRE

    Dillon, J R; Pauzé, M

    1981-01-01

    One hundred and forty strains of Neisseria gonorrhoeae, representing 12 different auxotype groups, were examined for differences in plasmid content. Most auxotype groups harbored a phenotypically cryptic 2,6-megadalton plasmid; a few groups also carried a 24.5-megadalton plasmid which has been previously characterized as a transfer plasmid. However, isolates of the proline-, citrulline-, and uracil-requiring (PCU-) auxotype were consistently free of plasmids. The correlation between auxotype ...

  7. Plasmid stability and maintenance of copy number using natural marker

    OpenAIRE

    Hamzah Basil Mohammed; Sudhakar Malla

    2015-01-01

    Present study was conducted to study the plasmid stability with the help of natural plasmid isolated from the bacteria which lodges the ink gland of the sea squid and emits bioluminescence. Isolated bacterial strain was identified by using 16srRNA sequencing and its plasmid DNA was used for the experimental studies. The plasmid is found to be responsible for the bioluminescence. The stability of this plasmid was studied in shake flask method using the different sugar sources (Gluc...

  8. Plasmids spread very fast in heterogeneous bacterial communities.

    OpenAIRE

    Dionisio, Francisco; Matic, Ivan; Radman, Miroslav; Rodrigues, Olivia R; Taddei, François

    2002-01-01

    Conjugative plasmids can mediate gene transfer between bacterial taxa in diverse environments. The ability to donate the F-type conjugative plasmid R1 greatly varies among enteric bacteria due to the interaction of the system that represses sex-pili formations (products of finOP) of plasmids already harbored by a bacterial strain with those of the R1 plasmid. The presence of efficient donors in heterogeneous bacterial populations can accelerate plasmid transfer and can spread by several order...

  9. Plasmid Segregation: Spatial Awareness at the Molecular Level

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Gerdes, Kenn

    2007-01-01

    In bacteria, low-copy number plasmids ensure their stable inheritance by partition loci (par), which actively distribute plasmid replicates to each side of the cell division plane. Using time-lapse fluorescence microscopic tracking of segregating plasmid molecules, a new study provides novel...... insight into the workings of the par system from Escherichia coli plasmid R1. Despite its relative simplicity, the plasmid partition spindle shares characteristics with the mitotic machinery of eukaryotic cells....

  10. Mobilization of Thiobacillus ferrooxidans plasmids among Escherichia coli strains.

    OpenAIRE

    Rawlings, D. E.; Woods, D R

    1985-01-01

    Nonconjugative Thiobacillus ferrooxidans plasmids were mobilized at high frequencies among Escherichia coli strains by the IncP plasmid RP4 and at low frequencies by the IncN plasmid R46, but not by the IncW plasmid pSa. The mobilization region of a nonconjugative T. ferrooxidans plasmid was located on a 5.3-kilobase T. ferrooxidans DNA fragment.

  11. Inducible Escherichia coli fermentation for increased plasmid DNA production.

    Science.gov (United States)

    Carnes, Aaron E; Hodgson, Clague P; Williams, James A

    2006-11-01

    Bacterial plasmids are the vectors of choice for DNA vaccines and short-term gene therapeutics. Growing plasmid DNA by microbial (Escherichia coli) fermentation is usually combined with alkaline lysis/chromatography methods of purification. To date, typical plasmid fermentation media and processes result in yields of 100-250 mg of plasmid DNA/l of culture medium, using standard high-copy pUC origin-containing plasmids. In order to address this initial and yield-limiting upstream step, we identified novel fermentation control parameters for fed-batch fermentation. The resulting fermentation strategies significantly increased specific plasmid yield with respect to cell mass while enhancing plasmid integrity and maintaining supercoiled DNA content. Fed-batch fermentation yield exceeding 1000 mg of plasmid DNA/l was obtained after reduction of plasmid-mediated metabolic burden during growth, and yields up to 1500 mg of plasmid DNA/l have been achieved with optimized plasmid backbones. Interestingly, by inducing high plasmid levels after sufficient biomass accumulation at low temperature and restricted growth, cells were able to tolerate significantly higher plasmid quantities than cells grown by conventional processes. This 5-10-fold increase in plasmid yield dramatically decreases plasmid manufacturing costs and improves the effectiveness of downstream purification by reducing the fraction of impurities. PMID:16819941

  12. Conservation of Salmonella typhimurium virulence plasmid maintenance regions among Salmonella serovars as a basis for plasmid curing.

    OpenAIRE

    Tinge, S A; Curtiss, R

    1990-01-01

    The association of large plasmids with virulence in invasive Salmonella serovars has led to a number of studies designed to uncover the role of these plasmids in virulence. This study addresses two aspects of virulence-associated plasmids. The first is the distribution of the replication and maintenance regions among the plasmids of different Salmonella serovars, and the second is the use of the conserved virulence plasmid par region to provide a rapid method for eliminating the virulence pla...

  13. Flagellar motility is necessary for Aeromonas hydrophila adhesion.

    Science.gov (United States)

    Qin, Yingxue; Lin, Guifang; Chen, Wenbo; Xu, Xiaojin; Yan, Qingpi

    2016-09-01

    Adhesion to host surface or cells is the initial step in bacterial pathogenesis, and the adhesion mechanisms of the fish pathogenic bacteria Aeromonas hydrophila were investigated in this study. First, a mutagenesis library of A. hydrophila that contained 332 random insertion mutants was constructed via mini-Tn10 Km mutagenesis. Four mutants displayed the most attenuated adhesion. Sequence analysis revealed that the mini-Tn10 insertion sites in the four mutant strains were flgC(GenBank accession numbers KX261880), cytb4(GenBank accession numbers JN133621), rbsR(GenBank accession numbers KX261881) and flgE(GenBank accession numbers JQ974982). To further study the roles of flgC and flgE in the adhesion of A. hydrophila, some biological characteristics of the wild-type strain B11, the mutants M121 and M240, and the complemented strains C121 and C240 were investigated. The results showed that the mutation in flgC or flgE led to the flagellar motility of A. hydrophila significant reduction or abolishment. flgC was not necessary for flagellar biosynthesis but was necessary for the full motility of A. hydrophila, flgE was involved in both flagellar biosynthesis and motility. The flagellar motility is necessary for A. hydrophila to adhere to the host mucus, which suggests flagellar motility plays crucial roles in the early infection process of this bacterium. PMID:27432325

  14. 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.; Heum, M.; Thornton, J.M.; Powell, R.

    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......-sets only. A. salmonicida subsp. salmonicida isolates tested, belonged to group 1. The PCR primer-sets separated A. salmonicida from other reference strains of Aeromonas species and related bacteria with the exception of Aeromonas hydrophila. The results indicated that PCR typing is a useful framework for...

  15. Survival of Aeromonas hydrophila and Listeria monocytogenes on fresh vegetables stored under moderate vacuum.

    Science.gov (United States)

    Aytac, S A; Gorris, L G

    1994-11-01

    Storage at 6.5°C under moderate vacuum effectively prevented growth of Aeromonas hydrophila on chicory endive, but had only a limited inhibitory effect on the growth of the organism on mung bean sprouts. Growth of Listeria monocytogenes on chicory endive was strongly stimulated under these conditions, whereas it was decreased on mung-bean sprouts. PMID:24421192

  16. 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...

  17. 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...

  18. Parasitism by protozoan Ichthyophthirius multifiliis enhanced invasion of Aeromonas hydrophila in tissues of channel catfish

    Science.gov (United States)

    Ichthyophthirius multifiliis Fouquet (Ich) and Aeromonas hydrophila are two common pathogens of cultured fish. Currently there is no information available for the effect of coinfection by Ich and A. hydrophila on bacterial load and survival in channel catfish. Two trials were conducted in this stud...

  19. Complete Genome Sequence of the Type Strain of Aeromonas schubertii, ATCC 43700

    Science.gov (United States)

    Liu, Lihui; Zhang, Defeng; Fu, Xiaozhe; Shi, Cunbin; Lin, Qiang

    2016-01-01

    We sequenced the complete genome of the type strain of Aeromonas schubertii, ATCC 43700. The full genome sequence of A. schubertii ATCC 43700 is 4,356,858 bp, which encodes 3,842 proteins and contains 110 predicted RNA genes. PMID:26893413

  20. 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...

  1. Flagellar apparatus gene sequences of Aeromonas hydrophila AL09-73 isolate

    Science.gov (United States)

    Flagellar apparatus genes of recent outbreak Aeromonas hydrophila AL09-73 isolate were sequenced and characterized. Total 28 flagellar genes were identified. The sizes of the genes range from 318 to 2001 nucleotides, which potentially encode different complex flagellar proteins. At nucleotide and...

  2. 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...

  3. Over-expression, purification and immune responses to Aeromonas hydrophila AL09-73 flagellar proteins

    Science.gov (United States)

    Aeromonas hydrophila is ubiquitous in aquatic environments worldwide and causes many diseases in fish as well as human. Recent outbreaks of aeromonad diseases in channel catfish prompted us to investigate catfish immune responses during infection of A. hydrophila. In this communication, we report ...

  4. 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...

  5. 2010 Surveillance for Aeromonas hydrophila outbreaks in the Alabama catfish industry

    Science.gov (United States)

    In 2009, a virulent strain of Aeromonas hydrophila was associated with severely acute to chronic mortality in catfish ponds in Alabama. This strain of A. hydrophila had not been previously identified in AL catfish. In a joint effort between the USDA ARS and Auburn University, a combination of appr...

  6. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  8. EFFECT OF ORAL IMMUNOSTIMULANT ANDROGRAPHIS PANICULATA AND RESISTANCE TO AEROMONAS HYDROPHILA IN CATLA CATLA

    OpenAIRE

    Innocent Xavier B.; Fathima Syed Ali M.; Sheeba; Sheeba S.

    2012-01-01

    The present study was designed to evaluate the immunostimulant potential of Andrographis paniculata in fish Catla catla, post challenged with Aeromonas hydrophila. Fishes were divided into 2 groups, one received control diet, and another received Andrographis paniculata incorporated diet for 14 days. The heamatological parameters and serum protein level were analyzed between control and experimental. There is a significant increase in TEC (P

  9. Antibiotic susceptibility profile of Aeromonas species isolated from wastewater treatment plant.

    Science.gov (United States)

    Igbinosa, Isoken H; Okoh, Anthony I

    2012-01-01

    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 bla(TEM) 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. PMID:22927788

  10. 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...

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

    DEFF Research Database (Denmark)

    Meinelt, Thomas; Phan, T.; Behrens, S.; Pedersen, Lars-Flemming; Wienke, A.; Liu, D.; Straus, David L.

    2015-01-01

    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...

  12. Genome Sequence of Aeromonas hydrophila Strain AH-3 (Serotype O34).

    Science.gov (United States)

    Forn-Cuní, Gabriel; Tomás, Juan M; Merino, Susana

    2016-01-01

    Aeromonas hydrophila is an emerging pathogen of poikilothermic animals, from fish to mammals, including humans. Here, we report the whole-genome sequence of the A. hydrophila AH-3 strain, isolated from a fish farm goldfish septicemia outbreak in Spain, with a characterized polar and lateral flagellum glycosylation pattern. PMID:27587828

  13. Rapid quantitative detection of Aeromonas hydrophila strains associated with disease outbreaks in catfish aquaculture

    Science.gov (United States)

    In the summer of 2009, a new strain of Aeromonas hydrophila was implicated in severe disease outbreaks in farm-raised catfish in Alabama, Arkansas and Mississippi. These outbreaks mostly afflicted large fish and resulted in considerable losses in short periods. Given the rapid onset and biosecurity ...

  14. Draft Genome Sequences of Four Virulent Aeromonas hydrophila Strains from Catfish Aquaculture

    Science.gov (United States)

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

    2016-01-01

    Since 2009, a clonal group of virulent Aeromonas hydrophila 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. PMID:27540076

  15. 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....

  16. fRNAdb Summary: FR276469 [

    Lifescience Database Archive (English)

    Full Text Available FR276469 AF508059,AF508086,AF516268 5.8S ribosomal RNA (rRNA) rRNA_5_8S Aeromonas ... media,Aeromonas ... s allosaccharophila,Aeromonas ... veronii bv. sobria RF00002 Rfam v8.1 FR276469.jpg ...

  17. fRNAdb Summary: FR088407 [

    Lifescience Database Archive (English)

    Full Text Available FR088407 AF508056,AF508088,AF516265 5.8S ribosomal RNA (rRNA) rRNA_5_8S Aeromonas ... veronii,Aeromonas ... nas encheleia,Aeromonas ... bestiarum RF00002 Rfam v8.1 FR088407.jpg FR088407. ...

  18. BioShuttle-mediated Plasmid Transfer

    Directory of Open Access Journals (Sweden)

    Klaus Braun, Leonie von Brasch, Ruediger Pipkorn, Volker Ehemann, Juergen Jenne, Herbert Spring, Juergen Debus, Bernd Didinger, Werner Rittgen, Waldemar Waldeck

    2007-01-01

    Full Text Available An efficient gene transfer into target tissues and cells is needed for safe and effective treatment of genetic diseases like cancer. In this paper, we describe the development of a transport system and show its ability for transporting plasmids. This non-viral peptide-based BioShuttle-mediated transfer system consists of a nuclear localization address sequence realizing the delivery of the plasmid phNIS-IRES-EGFP coding for two independent reporter genes into nuclei of HeLa cells. The quantification of the transfer efficiency was achieved by measurements of the sodium iodide symporter activity. EGFP gene expression was measured with Confocal Laser Scanning Microscopy and quantified with biostatistical methods by analysis of the frequency of the amplitude distribution in the CLSM images. The results demonstrate that the “BioShuttle”-Technology is an appropriate tool for an effective transfer of genetic material carried by a plasmid.

  19. BioShuttle-mediated Plasmid Transfer

    Science.gov (United States)

    Braun, Klaus; von Brasch, Leonie; Pipkorn, Ruediger; Ehemann, Volker; Jenne, Juergen; Spring, Herbert; Debus, Juergen; Didinger, Bernd; Rittgen, Werner; Waldeck, Waldemar

    2007-01-01

    An efficient gene transfer into target tissues and cells is needed for safe and effective treatment of genetic diseases like cancer. In this paper, we describe the development of a transport system and show its ability for transporting plasmids. This non-viral peptide-based BioShuttle-mediated transfer system consists of a nuclear localization address sequence realizing the delivery of the plasmid phNIS-IRES-EGFP coding for two independent reporter genes into nuclei of HeLa cells. The quantification of the transfer efficiency was achieved by measurements of the sodium iodide symporter activity. EGFP gene expression was measured with Confocal Laser Scanning Microscopy and quantified with biostatistical methods by analysis of the frequency of the amplitude distribution in the CLSM images. The results demonstrate that the “BioShuttle”-Technology is an appropriate tool for an effective transfer of genetic material carried by a plasmid. PMID:18026568

  20. Electrotransfer of Plasmid Vector DNA into Muscle

    Science.gov (United States)

    Miyazaki, Satsuki; Miyazaki, Jun-Ichi

    Wolff et al. (1990) first reported that plasmid DNA injected into skeletal muscle is taken up by muscle cells and the genes in the plasmid are expressed for more than two months thereafter, although the transfected DNA does not usually undergo chromosomal integration (Wolff et al., 1991, 1992). However, the relatively low expression levels attained by this method have hampered its applications for uses other than as a DNA vaccine (Davis et al., 1995). There are a number of reports analyzing the conditions that affect the efficiency of gene transfer by intramuscular DNA injection and assessing the fine structures of expression plasmid vectors that may affect expression levels (Davis et al., 1993; Liang et al., 1996; Norman et al., 1997). Furthermore, various attempts were done to improve the efficiency of gene transfer by intramus cular DNA injection. Consequently, regenerating muscle was shown to produce 80-fold or more protein than did normal muscle, following injection of an expression plas-mid. Muscle regeneration was induced by treatment with cardiotoxin or bupivacaine (Wells, 1993; Vitadello et al., 1994). We previously demonstrated that by combining a strong promoter and bupivacaine pretreatment intramuscular injection of an IL-5 expression plasmid results in IL-5 production in muscle at a level sufficient to induce marked proliferation of eosinophils in the bone marrow and eosinophil infiltration of various organs (Tokui et al., 1997). It was also reported that a single intramuscular injection of an erythropoietin expression plasmid produced physiologically significant elevations in serum erythropoietin levels and increased hematocrits in adult mice (Tripathy et al., 1996). Hematocrits in these animals remained elevated at >60% for at least 90 days after a single injection. However, improvements to this method have not been sufficient to extend its applications including clinical use.

  1. Multi-Drug Resistance Mediated by Class 1 Integrons in Aeromonas Isolated from Farmed Freshwater Animals.

    Science.gov (United States)

    Deng, Yuting; Wu, Yali; Jiang, Lan; Tan, Aiping; Zhang, Ruiquan; Luo, Li

    2016-01-01

    Aeromonas is regarded as an important pathogen of freshwater animals but little is known about the genetics of its antimicrobial resistance in Chinese aquaculture. The aim of this study was to investigate the presence of integrons and characterize multidrug resistant Aeromonas spp. isolated from diseased farmed freshwater animals. These animal samples included fish, ornamental fish, shrimp, turtles, and amphibians which were collected from 64 farms in Guangdong province of South China. One hundred and twelve Aeromonas spp. isolates were examined for antimicrobial resistance phenotypes and the presence of class 1 integron sequences. Twenty-two (19.6%) of these isolates carried a class 1 integron comprising six different gene insertion cassettes including drfA12-orfF-aadA2, drfA12-orfF, aac(6')-II-bla OXA-21 -cat3, catB3, arr-3, and dfrA17. Among these, drfA12-orfF-aadA2 was the dominant gene cassette array (63.6%, 14/22) and this is the first report of aac(6')-II-bla OXA-21 -cat3 in an Aeromonas hydrophila isolate from a Chinese giant salamander (Andrias davidianus). All the integron-positive strains were resistant to more than five agents and 22 contained other resistance genes including bla CTX-M-3, bla TEM-1, aac(6')-Ib-cr, and tetA. All integron-positive isolates also contained mutations in the quinolone resistance determining regions (QRDR). Our investigation demonstrates that freshwater animals can serve as a reservoir for pathogenic Aeromonas strains containing multiple drug-resistance integrons. This data suggests that surveillance for antimicrobial resistance of animal origin and a prudent and responsible use of antimicrobials in aquaculture is necessary in these farms. PMID:27379065

  2. Spontaneous bacterial peritonitis caused by Aeromonas caviae in a patient with cirrhosis.

    Science.gov (United States)

    Huang, Deyu; Zhao, Ying; Jiang, Yueping; Li, Zhongbin; Yang, Wucai; Chen, Guofeng

    2015-03-01

    Spontaneous bacterial peritonitis (SBP) is a common complication of cirrhosis. Based on our current understanding of SBP, the most common etiologies for SBP in cirrhosis are Enterobacter and Streptococcal species. Th e Aeromonas species are ubiquitous in fresh or sea water. Aeromonas caviae is never identified as etiology in cases of SBP. A patient, who had a history of liver cirrhosis related to chronic hepatitis B virus infection for 1 year, presented with diarrhea. He had diarrhea 1 week later returned from coastal city. He was hospitalized and treated with norfloxacin after 7 days of severe symptoms, including fever, abdominal distention, and diarrhea. Analysis of the ascitic specimen revealed a white-cell count of 4.42 × 109 cells/L with 88% neutrophils. Analysis of stool specimen showed a white-cell count of 60 cells per high-power field. Th e patient started the injection of cefriaxone at a dose of 4 g/d. However, the situation was not improved. Th ree days later, stool and ascitic fluid culture showed positive for Aeromonas caviae. Antibiotic susceptibility testing revealed that imipenem, meropenem, amikacin, and cefoperazone-sulbactam were highly sensitive to the Aeromonas caviae. However, the bacilli resisted to ceftriaxone, ceftazidime, ampicillin-sulbactam, levofloxacin, and sulfamethoxazole. Ceftriaxone was then switched to imipenem. The patient was fully recovered 14 days later. Aeromonas caviae is a rare pathogen of SBP in cirrhosis. It resists to third-generation of cephalosporin and fluroquinolone, which are of frequently used dependent on clinical experience. It needs a special attention. PMID:25832540

  3. Detection of toxigenic strains of Aeromonas species in foods by a multiplex PCR assay.

    Science.gov (United States)

    Balakrishna, K; Murali, H S; Batra, H V

    2010-06-01

    Aeromonas hydrophila and other aeromonads are ubiquitous organisms found in meat, vegetables, drinking water and various other food items. They cause diarrhea and extra-intestinal infections in normal and immunocompromised patients. The aim of the study was to develop a multiplex PCR assay for the detection of virulence-associated genes of Aeromonas including hemolysin (hlyA), aerolysin (aerA), glycerophospholipid-cholesterol acyl transferase (GCAT) alongwith a 16S rRNA gene. Internal amplification control (IAC), which was coamplified with aerA primers, was also included in this study. The results showed that all cultures of Aeromonas were accurately identified by the assay without showing non-specificity. A. hydrophila could be detected at a range of 10-50 CFU ml(-1) from experimentally spiked fish, chicken and milk samples following overnight enrichment in alkaline peptone water supplemented with 10 μg/ml ampicillin (APW-A) by this multiplex PCR (mPCR). When evaluated on a total of 74 naturally occurring food samples, four samples were identified to contain Aeromonas by mPCR. All these results were compared to the conventional culture, isolation and biochemical identification procedures. The high throughput and cost-effective mPCR method developed in this study could provide a powerful tool for detection of pathogenic Aeromonas spp. from food and environmental samples and in addition, the method has advantages in terms of specificity, sensitivity and ease of use compared to other reported PCR methods and DNA hybridization assays. PMID:23100820

  4. Aeromonas hydrophila subsp. ranae subsp. nov., isolated from septicaemic farmed frogs in Thailand.

    Science.gov (United States)

    Huys, Geert; Pearson, Marianne; Kämpfer, Peter; Denys, Rik; Cnockaert, Margo; Inglis, Valerie; Swings, Jean

    2003-05-01

    A group of seven sucrose-negative Aeromonas strains (referred to as group Au) isolated from the internal organs of septicaemic farmed frogs (Rana rugulosa) in Thailand was subjected to a polyphasic taxonomic study including fluorescent amplified fragment length polymorphism (FAFLP) and ERIC-PCR fingerprinting, 16S rDNA sequencing, microplate DNA-DNA hybridizations and extensive phenotypic characterization. Comparison of FAFLP and ERIC-PCR fingerprints indicated that the group Au isolates belonged to the species Aeromonas hydrophila DNA hybridization group (HG) 1 in which they represent a genotypic subgroup closely affiliated to A. hydrophila subsp. hydrophila and subsp. dhakensis. One representative of the Au group exhibited > or = 99.0% 16S rDNA sequence similarity with the type strains of the two A. hydrophila subspecies. DNA-DNA hybridization with type and reference strains of all known Aeromonas taxa revealed that the Au group represented a homogeneous taxon that exhibited the highest relatedness with members of the two A. hydrophila subspecies, ranging from 75 to 93%. Phenotypic characterization on the basis of 152 features further revealed that the Au group isolates differed from A. hydrophila subsp. hydrophila or subsp. dhakensis in a total of 13 biochemical properties. Of these, assimilation of L-glycine and isobutyrate as sole carbon source, acid production from salicin and D-sucrose, and aesculin hydrolysis were of diagnostic value. From the results of this study, it can be concluded that the Aeromonas frog isolates of the Au group represent a new subspecies of A. hydrophila, for which the name Aeromonas hydrophila subsp. ranae subsp. nov. is proposed. Its type strain is Au-1D12(T) (=LMG 19707(T) = CCUG 46211(T)). PMID:12807217

  5. BioShuttle-mediated Plasmid Transfer

    OpenAIRE

    Braun, Klaus; von Brasch, Leonie; Pipkorn, Ruediger; Ehemann, Volker; Jenne, Juergen; Spring, Herbert; Debus, Juergen; Didinger, Bernd; Rittgen, Werner; Waldeck, Waldemar

    2007-01-01

    An efficient gene transfer into target tissues and cells is needed for safe and effective treatment of genetic diseases like cancer. In this paper, we describe the development of a transport system and show its ability for transporting plasmids. This non-viral peptide-based BioShuttle-mediated transfer system consists of a nuclear localization address sequence realizing the delivery of the plasmid phNIS-IRES-EGFP coding for two independent reporter genes into nuclei of HeLa cells. The quantif...

  6. Competition between Plasmid-Bearing and Plasmid-Free Organisms in a Chemostat with Pulsed Input and Washout

    Directory of Open Access Journals (Sweden)

    Sanling Yuan

    2009-01-01

    Full Text Available We consider a model of competition between plasmid-bearing and plasmid-free organisms in the chemostat with pulsed input and washout. We investigate the subsystem with nutrient and plasmid-free organism and study the stability of the boundary periodic solutions, which are the boundary periodic solutions of the system. The stability analysis of the boundary periodic solution yields the invasion threshold of the plasmid-bearing organism. By using the standard techniques of bifurcation theory, we prove that above this threshold there are periodic oscillations in substrate, plasmid-free, and plasmid-bearing organisms. Numerical simulations are carried out to illustrate our results.

  7. Plasmid maintenance functions of the large virulence plasmid of Shigella flexneri.

    OpenAIRE

    Radnedge, L; Davis, M. A.; Youngren, B; Austin, S. J.

    1997-01-01

    The large virulence plasmid pMYSH6000 of Shigella flexneri contains a replicon and a plasmid maintenance stability determinant (Stb) on adjacent SalI fragments. The presence of a RepFIIA replicon on the SalI C fragment was confirmed, and the complete sequence of the adjacent SalI O fragment was determined. It shows homology to part of the transfer (tra) operon of the F plasmid. Stb stabilizes a partition-defective P1 miniplasmid in Escherichia coli. A 1.1-kb region containing a homolog of the...

  8. Plasmid transfer and plasmid-mediated genetic exchange in Brucella abortus.

    OpenAIRE

    Rigby, C E; Fraser, A.D.

    1989-01-01

    Naturally-occurring plasmids and gene transfer mechanisms have not yet been reported in brucellae. Here we show that Brucella abortus is capable of maintaining and transferring the broad-host-range plasmids pTH10 (IncP), pSa (IncW) and R751 (IncP), and describe pTH10-mediated transfer of B. abortus chromosomal genes to Escherichia coli. All three plasmids transferred by conjugation from E. coli to B. abortus S19, and from B. abortus S19 to B. abortus 292 (biovar 4). They were stably maintaine...

  9. Plasmid transduction by Bacillus subtilis bacteriophage SPP1: effects of DNA homology between plasmid and bacteriophage.

    OpenAIRE

    Deichelbohrer, I; Alonso, J.C.; Lüder, G; Trautner, T A

    1985-01-01

    Any SPP1 DNA restriction fragment cloned into Bacillus subtilis plasmid pC194 or pUB110 increased the transduction frequency of the plasmid by SPP1 100- to 1,000-fold over the transduction level of the plasmid alone. This increment was observed irrespective of whether a fragment contained the SPP1 packaging origin (pac). Furthermore, an SPP1 derivative into whose genome pC194 DNA had been integrated transduced pC194 DNA with a greatly enhanced frequency. Transduction enhancement mediated by D...

  10. Control of Aeromonas on minimally processed vegetables by decontamination with lactic acid, chlorinated water, or thyme essential oil solution.

    Science.gov (United States)

    Uyttendaele, M; Neyts, K; Vanderswalmen, H; Notebaert, E; Debevere, J

    2004-02-01

    Aeromonas is an opportunistic pathogen, which, although in low numbers, may be present on minimally processed vegetables. Although the intrinsic and extrinsic factors of minimally processed prepacked vegetable mixes are not inhibitory to the growth of Aeromonas species, multiplication to high numbers during processing and storage of naturally contaminated grated carrots, mixed lettuce, and chopped bell peppers was not observed. Aeromonas was shown to be resistant towards chlorination of water, but was susceptible to 1% and 2% lactic acid and 0.5% and 1.0% thyme essential oil treatment, although the latter provoked adverse sensory properties when applied for decontamination of chopped bell peppers. Integration of a decontamination step with 2% lactic acid in the processing line of grated carrots was shown to have the potential to control the overall microbial quality of the grated carrots and was particularly effective towards Aeromonas. PMID:14751681

  11. An Asian Origin of Virulent Aeromonas hydrophila Responsible for Disease Epidemics in United States-Farmed Catfish

    OpenAIRE

    Hossain, Mohammad J.; Sun, Dawei; McGarey, Donald J.; Wrenn, Shannon; Alexander, Laura M.; Martino, Maria Elena; Xing, Ye; Terhune, Jeffery S.; Liles, Mark R.

    2014-01-01

    ABSTRACT Since 2009, catfish farming in the southeastern United States has been severely impacted by a highly virulent and clonal population of Aeromonas hydrophila causing motile Aeromonas septicemia (MAS) in catfish. The possible origin of this newly emerged highly virulent A. hydrophila strain is unknown. In this study, we show using whole-genome sequencing and comparative genomics that A. hydrophila isolates from diseased grass carp in China and catfish in the United States have highly si...

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

    Science.gov (United States)

    Praveen, Praveen Kumar; Debnath, Chanchal; Shekhar, Shashank; Dalai, Nirupama; Ganguly, Subha

    2016-01-01

    Aeromonas is recognized to cause a variety of diseases in man. In humans, they are associated with intestinal and extra-intestinal 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. PMID:27051177

  13. 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.

  14. White Mulberry (Morus alba) Foliage Methanolic Extract Can Alleviate Aeromonas hydrophila Infection in African Catfish (Clarias gariepinus)

    OpenAIRE

    Atefeh Sheikhlar; Abd Razk Alimon; Hassan Daud; Saad, Chee R.; Webster, Carl D.; Goh Yong Meng; Mahdi Ebrahimi

    2014-01-01

    Two experiments were simultaneously conducted with Morus alba (white mulberry) foliage extract (MFE) as a growth promoter and treatment of Aeromonas hydrophila infection in separate 60 and 30 days trail (Experiments 1 and 2, resp.) in African catfish (Clarias gariepinus). In Experiment 1, four diets, control and control supplemented with 2, 5, or 7 g MFE/kg dry matter (DM) of diet, were used. In Experiment 2, fish were intraperitoneally infected with Aeromonas hydrophila and fed the same diet...

  15. 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.

  16. Quinolone resistant Aeromonas spp. as carriers and potential tracers of acquired antibiotic resistance in hospital and municipal wastewater

    OpenAIRE

    Varela, Ana Rita; Nunes, Olga C.; Manaia, Célia

    2016-01-01

    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 divers...

  17. Occurrence of potential pathogenic Aeromonas species in tropical seafood, aquafarms and mangroves off Cochin coast in South India

    OpenAIRE

    Alphonsa Vijaya Joseph; Raghul Subin Sasidharan; Harisree P Nair; Bhat, Sarita G.

    2013-01-01

    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...

  18. Plasmid maintenance and protein overproduction in selective recycle bioreactors.

    Science.gov (United States)

    Ogden, K L; Davis, R H

    1991-02-20

    A new plasmid construct has been used in conjunction with selective recycle to successfully maintain otherwise unstable plasmid-bearing E. coli cells in a continuous bioreactor and to produce significant amounts of the plasmid-encoded protein beta-lactamase. The plasmid is constructed so that pilin expression, which leads to bacterial flocculation, is under control of the tac operon. The plasmid-bearing cells are induced to flocculate in the separator, whereas cell growth and product synthesis occur in the main fermentation vessel without the inhibiting effects of pilin production. Selective recycle allows for the maintenance of the plasmid-bearing cells by separating flocculent, plasmid-bearing cells from nonflocculent, segregant cells in an inclined settler, and recycling only the plasmid-bearing cells to the reactor. As a result, product expression levels are maintained that are more than ten times the level achieved without selective recycle. All experimental data agree well with theoretical predictions. PMID:18597374

  19. Simple method for identification of plasmid-coded proteins

    International Nuclear Information System (INIS)

    Proteins encoded by plasmid DNA are specifically labeled in uv-irradiated cells of Escherichia coli carrying recA and uvrA mutations because extensive degradation of the chromosome DNA occurs concurrently with amplification of plasmid DNA

  20. DISTRIBUTION OF PLASMIDS IN GROUNDWATER BACTERIA

    Science.gov (United States)

    Bacteria isolated from groundwater aquifer core materials of pristine aquifers at Lula and Pickett, Oklahoma, and from a site with a history of aromatic hydrocarbon contamination and natural renovation located at Conroe, Texas, were screened for the presence of plasmid Deoxyribon...

  1. Plasmid mediated quinolone resistance in Enterobacteriaceae

    NARCIS (Netherlands)

    Veldman, K.T.

    2014-01-01

    This thesis describes the occurrence of Plasmid Mediated Quinolone Resistance (PMQR) in Salmonella and E. coli from The Netherlands and other European countries. Furthermore, the genetic background of these genes was characterized. Fluoroquinolones are widely used antibiotics in both human and veter

  2. Production of a bioflocculant from Pseudomonas veronii L918 using the hydrolyzate of peanut hull and its application in the treatment of ash-flushing wastewater generated from coal fired power plant.

    Science.gov (United States)

    Liu, Weijie; Hao, Yan; Jiang, Jihong; Zhu, Aihua; Zhu, Jingrong; Dong, Zhen

    2016-10-01

    In this study, bioflocculant produced by Pseudomonas veronii L918 was applied to treat ash-flushing wastewater. The strain L918 could convert the hydrolyzate of peanut hull into bioflocculant, which can effectively reduce the production cost of bioflocculant. The yield of 3.39g/L bioflocculant MBF-L918 was achieved when 300mL/L peanut hull hydrolyzate was used as carbon source. The bioflocculant MBF-L918 contains 77.14% polysaccharides and 4.84% proteins, and the molecular weight (MW) of MBF-L918 is 24.77kDa. Furthermore, MBF-L918 showed good flocculating efficiency of 92.51% to ash-flushing wastewater when 2.83mg/L MBF-L918 was added, and thus achieved the recycling of ash-flushing wastewater. This study reported for the first time that the bioflocculant was produced using peanut hull hydrolyzate and effectively applied in the treatment of coal ash-flushing wastewater. PMID:27372012

  3. 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®.

  4. PHENOTYPING, VIRULENCE CHARACTERISTICS OF AEROMONAS SPECIES AND THE EFFECTS OF ESSENTIAL PLANT OILS AS ANTIMICROBIAL AGENTS AGAINST PATHOGENIC ISOLATES FROM DIFFERENT SOURCES

    OpenAIRE

    Ahmed M.A. Mansour; Hoda M. Zaki; Nibal A. Hassan; Nihad A.M. El-Nashar

    2014-01-01

    Aeromonas species are increasingly recognized as enteric pathogens. Faecal samples from 20 cow, 45 sheep; 60 goat and 60 camels were examined for the presence of Aeromonas species, which was also sought in the available drinking water (55 well water and 52 drinking chlorinated tap water were also examined). Aeromonas species was isolated more frequently from goats (21.7%) than from other animal groups sampled and isolated more frequentl...

  5. Determination of Microbial Diversity of Aeromonas Strains on the Basis of Multilocus Sequence Typing, Phenotype, and Presence of Putative Virulence Genes ▿ †

    OpenAIRE

    Martino, Maria Elena; Fasolato, Luca; Montemurro, Filomena; Rosteghin, Marina; Manfrin, Amedeo; Patarnello, Tomaso; Novelli, Enrico; Cardazzo, Barbara

    2011-01-01

    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 ...

  6. The influence of biofilms in the biology of plasmids

    OpenAIRE

    Cook, Laura C.C.; Dunny, Gary M.

    2014-01-01

    The field of plasmid biology has historically focused on bacteria growing in liquid culture. Surface attached communities of bacterial biofilms have recently been understood to be the normal environment of bacteria in the natural world. Thus, studies examining plasmid replication, maintenance, and transfer in biofilms are essential for a true understanding of bacterial plasmid biology. This chapter reviews the current knowledge of the interplay between bacterial biofilms and plasmids, focusin...

  7. The 2 micron plasmid purloins the yeast cohesin complex

    OpenAIRE

    Mehta, Shwetal; Yang, Xian Mei; Chan, Clarence S.; Dobson, Melanie J.; Jayaram, Makkuni; Velmurugan, Soundarapandian

    2002-01-01

    The yeast 2 micron plasmid achieves high fidelity segregation by coupling its partitioning pathway to that of the chromosomes. Mutations affecting distinct steps of chromosome segregation cause the plasmid to missegregate in tandem with the chromosomes. In the absence of the plasmid stability system, consisting of the Rep1 and Rep2 proteins and the STB DNA, plasmid and chromosome segregations are uncoupled. The Rep proteins, acting in concert, recruit the yeast cohesin complex to the STB locu...

  8. Linear and Circular Plasmid Content in Borrelia burgdorferi Clinical Isolates

    OpenAIRE

    Iyer, Radha; Kalu, Ogori; Purser, Joye; Norris, Steven; Stevenson, Brian; Schwartz, Ira

    2003-01-01

    The genome of Borrelia burgdorferi, the etiologic agent of Lyme disease, is composed of a linear chromosome and more than 20 linear and circular plasmids. Typically, plasmid content analysis has been carried out by pulsed-field gel electrophoresis and confirmed by Southern hybridization. However, multiple plasmids of virtually identical sizes (e.g., lp28 and cp32) complicate the interpretation of such data. The present study was undertaken to investigate the complete plasmid complements of B....

  9. Plasmid DNA entry into postmitotic nuclei of primary rat myotubes.

    OpenAIRE

    Dowty, M E; Williams, P; Zhang, G.; Hagstrom, J E; Wolff, J A

    1995-01-01

    These studies were initiated to elucidate the mechanism of DNA nuclear transport in mammalian cells. Biotin- or gold-labeled plasmid and plasmid DNA expression vectors for Escherichia coli beta-galactosidase or firefly luciferase were microinjected into the cytoplasm of primary rat myotubes in culture. Plasmid DNA was expressed in up to 70% of the injected myotubes, which indicates that it entered intact, postmitotic nuclei. The nuclear transport of plasmid DNA occurred through the nuclear po...

  10. Postsegregational killing does not increase plasmid stability but acts to mediate the exclusion of competing plasmids

    OpenAIRE

    Cooper, Tim F; Heinemann, Jack A.

    2000-01-01

    Postsegregational killing (PSK) systems consist of a tightly linked toxin–antitoxin pair. Antitoxin must be continually produced to prevent the longer lived toxin from killing the cell. PSK systems on plasmids are widely believed to benefit the plasmid by ensuring its stable vertical inheritance. However, experimental tests of this “stability” hypothesis were not consistent with its predictions. We suggest an alternative hypothesis to explain the evolution of PSK: ...

  11. Plasmid Capture by the Bacillus thuringiensis Conjugative Plasmid pXO16▿

    OpenAIRE

    Timmery, Sophie; Modrie, Pauline; Minet, Olivier; Mahillon, Jacques

    2009-01-01

    Conjugation, mobilization, and retromobilization are three related mechanisms of horizontal gene transfer in bacteria. They have been extensively studied in gram-negative species, where retromobilization, the capture of DNA from a recipient by a donor cell, was shown to result from two successive steps: the transfer of the conjugative plasmid from the donor to the recipient followed by the retrotransfer of the mobilizable plasmid to the donor. This successive model was established for gram-ne...

  12. Conjugative plasmids: Vessels of the communal gene pool

    DEFF Research Database (Denmark)

    Norman, Anders; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    over large taxonomic distances. These plasmids are collections of discrete regions of genes that function as ‘backbone modules' to undertake different aspects of overall plasmid maintenance and propagation. Conjugative plasmids often carry suites of ‘accessory elements' that contribute adaptive traits...

  13. Compositional discordance between prokaryotic plasmids and host chromosomes

    Directory of Open Access Journals (Sweden)

    van Kampen Antoine HC

    2006-02-01

    Full Text Available Abstract Background Most plasmids depend on the host replication machinery and possess partitioning genes. These properties confine plasmids to a limited range of hosts, yielding a close and presumably stable relationship between plasmid and host. Hence, it is anticipated that due to amelioration the dinucleotide composition of plasmids is similar to that of the genome of their hosts. However, plasmids are also thought to play a major role in horizontal gene transfer and thus are frequently exchanged between hosts, suggesting dinucleotide composition dissimilarity between plasmid and host genome. We compared the dinucleotide composition of a large collection of plasmids with that of their host genomes to shed more light on this enigma. Results The dinucleotide frequency, coined the genome signature, facilitates the identification of putative horizontally transferred DNA in complete genome sequences, since it was found to be typical for a certain genome, and similar between related species. By comparison of the genome signature of 230 plasmid sequences with that of the genome of each respective host, we found that in general the genome signature of plasmids is dissimilar from that of their host genome. Conclusion Our results show that the genome signature of plasmids does not resemble that of their host genome. This indicates either absence of amelioration or a less stable relationship between plasmids and their host. We propose an indiscriminate lifestyle for plasmids preserving the genome signature discordance between these episomes and host chromosomes.

  14. Competition between Plasmid-Bearing and Plasmid-Free Organisms in a Chemostat with Pulsed Input and Washout

    OpenAIRE

    Sanling Yuan; Yu Zhao; Anfeng Xiao

    2009-01-01

    We consider a model of competition between plasmid-bearing and plasmid-free organisms in the chemostat with pulsed input and washout. We investigate the subsystem with nutrient and plasmid-free organism and study the stability of the boundary periodic solutions, which are the boundary periodic solutions of the system. The stability analysis of the boundary periodic solution yields the invasion threshold of the plasmid-bearing organism. By using the standard techniques of bifurcation theory, w...

  15. Co-segregation of yeast plasmid sisters under monopolin-directed mitosis suggests association of plasmid sisters with sister chromatids

    OpenAIRE

    Liu, Yen-Ting; Ma, Chien-Hui; Jayaram, Makkuni

    2013-01-01

    The 2-micron plasmid, a high copy extrachromosomal element in Saccharomyces cerevisiae, propagates itself with nearly the same stability as the chromosomes of its host. Plasmid stability is conferred by a partitioning system consisting of the plasmid-coded proteins Rep1 and Rep2 and a cis-acting locus STB. Circumstantial evidence suggests that the partitioning system couples plasmid segregation to chromosome segregation during mitosis. However, the coupling mechanism has not been elucidated. ...

  16. THE INTEGRATED STATE OF THE ROLLING-CIRCLE PLASMID PTB913 IN THE COMPOSITE BACILLUS PLASMID PTB19

    NARCIS (Netherlands)

    OSKAM, L; HILLENGA, DJ; VENEMA, G; BRON, S

    1992-01-01

    pTB19, a 27 kb plasmid originating from a thermophilic Bacillus species, contains integrated copies of two rolling-circle type plasmids on a 10.6 kb DNA fragment. In the present study we analysed the part of pTB19 that contains the rolling-circle plasmid pTB913 and the region in between the two roll

  17. 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., ...

  18. Stable inheritance of plasmid R1 requires two different loci.

    OpenAIRE

    Gerdes, K; Larsen, J E; Molin, S

    1985-01-01

    The largest EcoRI fragment from plasmid R1 mediates a stability phenotype which is required to ensure the stable inheritance of this low-copy-number plasmid. When covalently linked to small, unstable R1 derivatives, this fragment makes the plasmids as stable as the wild-type R1 plasmid. A genetic analysis showed that two independently acting stabilization functions are encoded by this EcoRI fragment, both of which have the potential of partial stabilization of mini-R1 plasmids. The two loci a...

  19. DNA restriction-modification systems mediate plasmid maintenance.

    OpenAIRE

    Kulakauskas, S; Lubys, A; Ehrlich, S. D.

    1995-01-01

    Two plasmid-carried restriction-modification (R-M) systems, EcoRI (from pMB1 of Escherichia coli) and Bsp6I (from pXH13 of Bacillus sp. strain RFL6), enhance plasmid segregational stability in E. coli and Bacillus subtilis, respectively. Inactivation of the endonuclease or the presence of the methylase in trans abolish the stabilizing activity of the R-M systems. We propose that R-M systems mediate plasmid segregational stability by postsegregational killing of plasmid-free cells. Plasmid-enc...

  20. Antibiotic susceptibility profile of Aeromonas spp. isolates from food in Abu Dhabi, United Arab Emirates.

    Science.gov (United States)

    Awan, Mohammad Bashir; Maqbool, Ahmed; Bari, Abdul; Krovacek, Karel

    2009-01-01

    A total of 57 Aeromonas isolates from food samples such as fresh and frozen chicken, game birds, pasteurized milk, baby food, bakery products, fruit and vegetables, fish, and water from Abu Dahbi, UAE were investigated for antibiotic susceptibility profile. Most strains were resistant to penicillins (ticarcillin, mezlocillin, oxacillin, piperacillin), sulfamethoxazole, trimethoprim and macrolides (erythromycin, vancomycin, clindamycin) but sensitive to tetracycline, chloramphenicol, nitrofurantoin, aminoglycosides (amikacin, gentamicin, tobramycin), cephalosporins (cefuroxime, ceftrioxone, cefazolin, cephalexin, cephalothin, cefoxitin, cefotaxime), quinolone (ciprofloxacin), colistin sulphate and SXT (trimethoprim-sulfamethoxazole). On the other hand, many antibiotics showed excellent inhibitory activity (>75% strains were sensitive to them) against all the strains tested. These include cefuroxime, ceftrioxone, ciprofloxacin, colistin, amikacin, gentamicin, tetracycline, chloramphenicol, nitrofurantoin, cefotaxime and tobramycin. In conclusion, the results show a detailed pattern of sensitivity of the various Aeromonas spp. isolates to a variety of antibiotics and provide useful information in the context of selective isolation and phenotypic identification of the aeromonads from food. PMID:19382665

  1. Isolation of a lytic bacteriophage against virulent Aeromonas hydrophila from an organized equine farm.

    Science.gov (United States)

    Anand, Taruna; Vaid, Rajesh Kumar; Bera, Bidhan Ch; Singh, Jitender; Barua, Sanjay; Virmani, Nitin; K, Rajukumar; Yadav, Neeraj Kumar; Nagar, Dinesh; Singh, Raj K; Tripathi, B N

    2016-04-01

    A bacteriophage (VTCCBPA6) against a pathogenic strain of Aeromonas hydrophila was isolated from the sewage of an organized equine breeding farm. On the basis of TEM analysis, phage belonged to family Myoviridae. PCR amplification and sequence analysis of gp23 gene (encoding for major capsid protein) revealed phylogenetic resemblance to T4 like virus genus. Protein profiling by SDS-PAGE also indicated its resemblance to T4 like phage group. However, the comparison of its gp23 gene sequence with previously reported phages showed similarity with T4-like phages infecting Enterobacteriaceae instead of Aeromonas spp. Thus, to our knowledge, this report points toward the fact that a novel/evolved phage might exist in equine environment against A. hydrophila, which can be potentially used as a biocontrol agent. PMID:26748732

  2. EFFECT OF ORAL IMMUNOSTIMULANT ANDROGRAPHIS PANICULATA AND RESISTANCE TO AEROMONAS HYDROPHILA IN CATLA CATLA

    Directory of Open Access Journals (Sweden)

    Innocent Xavier B.

    2012-04-01

    Full Text Available The present study was designed to evaluate the immunostimulant potential of Andrographis paniculata in fish Catla catla, post challenged with Aeromonas hydrophila. Fishes were divided into 2 groups, one received control diet, and another received Andrographis paniculata incorporated diet for 14 days. The heamatological parameters and serum protein level were analyzed between control and experimental. There is a significant increase in TEC (P<0.05 and TLC (P<0.01 in immune-stimulant incorporated diet (IS. Remarkable increase in Hb content and serum protein was noticed as 2.42 to 3.2g% and 0.52 to 0.98g% respectively. The immunostimulant administered Cata catla when challenged with Aeromonas hydrophila showed decrease in TEC and drastic increase in TLC (P < 0.01 and lymphocyte as 58% when compared to control.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, S L; Lye, D J; McKinstry, Craig A.; Vesper, Sephen J.

    2010-01-01

    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 murine small intestinal extracts, 24 hours after oral infection with an A. caviae strain, provides evidence of a Th1 type immune response. A large number of gamma-interferon (γ-IFN) induced genes are up-regulated as well as several tumor necrosis factor-alpha (TNF-α) transcripts. A. caviae has always been considered as opportunistic pathogen because it lacks obvious virulence factors. This current effort suggests that an A. caviae strain can colonize the murine intestinal tract and cause what has been described by others as a dysregulatory cytokine response. This response could explain why a number of diarrheal waterborne disease cases have been attributed to A. caviae even though it lacks obvious enteropathogenic properties.

  4. Role of Plasmid in Production of Acetobacter Xylinum Biofilms

    Directory of Open Access Journals (Sweden)

    Abbas Rezaee

    2005-01-01

    Full Text Available Acetobacter xylinum has the ability to produce cellulotic biofilms. Bacterial cellulose is expected to be used in many industrial or biomedical materials for its unique characteristics. A. xylinum contains a complex system of plasmid DNA molecules. A 44 kilobases (kb plasmid was isolated in wild type of A. xylinum. To improve the cellulose producing ability of A. xylinum, role of the plasmid in production of cellulose was studied. The comparisons between wild type and cured cells of A. xylinum showed that there is considerably difference in cellulose production. In order to study the relationship between plasmid and the rate of cellulose production, bacteria were screened for plasmid profile by a modified method for preparation of plasmid. This method yields high levels of pure plasmid DNA that can be used for common molecular techniques, such as digestion and transformation, with high efficiency.

  5. Phytoextracts-Synthesized Silver Nanoparticles Inhibit Bacterial Fish Pathogen Aeromonas hydrophila

    OpenAIRE

    Mahanty, Arabinda; Mishra, Snehasish; Bosu, Ranadhir; Maurya, UK; Netam, Surya Prakash; Sarkar, Biplab

    2013-01-01

    Fish disease is a major stumbling block towards sustainable growth of the fisheries sector. Aeromonas hydrophila, which is a major infectious aquatic pathogen is reportedly the causative agent of ulcers, fin-rot, tail-rot, hemorrhagic septicemia in fish, and has reportedly developed resistance against many of the available antibiotics. In this context, the inhibitory function of silver nanoparticles (AgNPs) against A. hydrophila was studied to evaluate its possible application in aquaculture ...

  6. 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. PMID:16797762

  7. Isolation of enterotoxigenic, hemolytic, and antibiotic-resistant Aeromonas hydrophila strains from infected fish in Bangladesh.

    OpenAIRE

    Z. Rahim; Sanyal, S C; Aziz, K M; Huq, M I; Chowdhury, A A

    1984-01-01

    Strains of Aeromonas hydrophila isolated from skin infections of common freshwater fish in Bangladesh were tested for enterotoxin production, hemolysin production, and any correlation between these two activities. We also tested the resistance patterns of A. hydrophila to different drugs, especially in relation to ampicillin. The A. hydrophila strains produced an enterotoxin that was related to their beta-hemolytic activities. Production of beta-hemolysin may thus be an indicator of enterotox...

  8. Chemical modification of polyvinyl chloride and silicone elastomer in inhibiting adhesion of Aeromonas hydrophila

    OpenAIRE

    Kregiel, Dorota; Berlowska, Joanna; Mizerska, Urszula; Fortuniak, Witold; Chojnowski, Julian; Ambroziak, Wojciech

    2013-01-01

    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 a...

  9. Aeromonas hydrophila-associated skin lesions and septicaemia in a Nile crocodile (Crocodylus niloticus) : clinical communication

    OpenAIRE

    H. Turutoglu; S. Ercelik; M. Corlu

    2005-01-01

    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...

  10. Diagnosis of Aeromonas hydrophila, Mycobacterium species, and Batrachochytrium dendrobatidis in an African Clawed Frog (Xenopus laevis)

    OpenAIRE

    Hill, William A; Newman, Shelley J; Craig, Linden; Carter, Christopher; Czarra, Jane; Brown, J Paige

    2010-01-01

    Here we describe diagnosis of concurrent infection with Aeromonas hydrophila, Mycobacterium spp., and Batrachochytrium dendrobatidis in a wild female Xenopus laevis captured in Chile and transported to the United States. After approximately 130 d in the laboratory, the frog was presented for dysecdysis and obtundation. After euthanasia, tissues were submitted for histopathologic evaluation and PCR analysis for B. dendrobatidis and Ranavirus. Clinically significant gross lesions included cutan...

  11. Bioremediation and Detoxification of Synthetic Wastewater Containing Triarylmethane Dyes by Aeromonas hydrophila Isolated from Industrial Effluent

    OpenAIRE

    Chimezie Jason Ogugbue; Thomas Sawidis

    2011-01-01

    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 f...

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

    OpenAIRE

    Davood Ommi; Seyed Mohammadreza Hashemian; Elahe Tajbakhsh; Faham Khamesipour

    2015-01-01

    ABSTRACT 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 Aer...

  13. Antibacterial activities of bioactive compounds extracted from Marine algae Gracilaria salicornia against Aeromonas hydrophila

    OpenAIRE

    Somayeh Rasooli; Masoud Sattari; Zohreh Ramezanpour; Javid Imanpour Namin

    2015-01-01

    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 Isl...

  14. 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.

  15. COMBINATION OF CONVENTIONAL AND IN-SILICO APPROACH FOR IDENTIFYING AN INDUSTRIALLY IMPORTANT ISOLATE OF AEROMONAS

    Directory of Open Access Journals (Sweden)

    Thungri Ghoshal

    2014-01-01

    Full Text Available Ammonia is required for various commercial applications while its production by standard process is immensely energy intense. Dairy industry on the other hand produces huge volume of effluent needing treatment before discharge. This study aims at developing an eco-friendly microbial approach for conversion of dairy industry effluent into ammonia under atmospheric pressure and 37°C temperature at laboratory scale. Thus the need for huge energy for ammonia production would be avoided. Moreover the dairy effluent would generate revenue while getting treated. This study is also an attempt to develop a bioinformatics approach for strain identification. Standard cultivation techniques and in-silico approach of analysis of draft genome was undertaken to decipher the identity of this industrially important strain. Aeromonas sp. MCC 2167 (isolated from active dairy sludge was capable of treating un-amended dairy effluent with 6% inoculum while producing ammonia as by product at a 11 folds higher rate than the modified Habers Process. Though the strain showed maximum identity with Aeromonas hydrophila, there were certain differences in terms of substrate utilization. Majority of the contigs showed identity with Aeromonas hydrophila, however there was significant difference among the two strains in terms of intergenomic distance (genome to genome distance calculator from DSMZ, inversion and frame shift (dot plot analysis as well as genome rearrangement (MAUVE analysis. As per the rapid annotation using subsystem technology analysis 53% of the contigs belong to the subsystem category while the remaining 47% do not match with existing sequences in the database. The above finding proposes bioinformatics validation of the wetlab based data pointing towards this industrially important strain to be a novel isolate of Aeromonas sp. This would lead to an energy efficient economically viable alternative for ammonia production while

  16. Recombinant outer membrane protein C of Aeromonas hydrophila elicits mixed immune response and generates agglutinating antibodies.

    Science.gov (United States)

    Yadav, Sunita Kumari; Meena, Jitendra Kumar; Sharma, Mahima; Dixit, Aparna

    2016-08-01

    Aeromonas hydrophila is a gram-negative fish pathogenic bacterium, also responsible for causing opportunistic pathological conditions in humans. It causes a number of diseases in fish due to which the fish industry incurs huge economic losses annually. Due to problems of antibiotic resistance, and the rapidity with which the infection spreads among fishes, vaccination remains the most effective strategy to combat this infection in fish populations. Among various virulence factors associated with bacterial virulence, outer membrane proteins have been widely evaluated for their vaccine potential owing to their surface exposure and related role in pathogenicity. In the present study, we have investigated the immunogenic potential of a non-specific porin, outer membrane protein C (OmpC) whose expression is regulated by the two-component regulatory system and plays a major role in the survival of A. hydrophila under different osmolaric conditions. The full-length gene (~1 kb) encoding OmpC of A. hydrophila was cloned, characterized and expressed in E. coli. High yield (~112 mg/L at shake flask level) of the recombinant OmpC (rOmpC) (~40 kDa) of A. hydrophila was obtained upon purification from inclusion bodies using Ni(2+)-NTA affinity chromatography. Immunization with purified rOmpC in murine model generated high endpoint (>1:40,000) titers. IgG isotyping, ELISA and ELISPOT assay indicated mixed immune response with a TH2 bias. Also, the anti-rOmpC antibodies were able to agglutinate A. hydrophila in vitro and exhibited specific cross-reactivity with different Aeromonas strains, which will facilitate easy detection of different Aeromonas isolates in infected samples. Taken together, these data clearly indicate that rOmpC could serve as an effective vaccine against different strains of Aeromonas, a highly heterogenous group of bacteria. PMID:27328672

  17. Detection of multidrug resistance Aeromonas hydrophila in farm raised fresh water prawns

    OpenAIRE

    Md. Bakhtiar Lijon; Mst. Mousumi Khatun; Ariful Islam; Mst. Minara Khatun; Md. Ariful Islam

    2015-01-01

    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 enrich...

  18. Purification and Characterization of Aeromonas caviae ME-1 Xylanase V, Which Produces Exclusively Xylobiose from Xylan

    OpenAIRE

    Kubata, Bruno Kilunga; Suzuki, Tohru; Horitsu, Hiroyuki; Kawai, Keiichi; Takamizawa, Kazuhiro

    1994-01-01

    A xylanase, which produces exclusively xylobiose from oat spelt and birch xylans, was isolated from the culture medium of Aeromonas caviae ME-1. The enzyme (xylanase V) was purified by ammonium sulfate fractionation, hydrophobic interaction, and ion-exchange and gel filtration chromatographies. The homogeneity of the final preparation was demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and agarose gel electrofocusing. The molecular mass and isoelectric point of the x...

  19. Antibiotic and heavy metal resistance of Aeromonas hydrophila isolated from charal (Chirostoma humboldtianum, Valenciannes, 1835)

    OpenAIRE

    Gloria Luz Paniagua; Eric Monroy; Magdalena Perches; Erasmo Negrete; Octavio García; Sergio Vaca

    2006-01-01

    Antibiotic and heavy metal susceptibilities of twenty Aeromonas hydrophila strains, isolated from the gastrointestinal tract of the charal (Chirostoma humboldtianum), an autochthonous Mexican fish, were analyzed. All strains produced #946;-lactamase and were resistant to penicillin and dicloxacillin, showing single peak for minimum inhibitory concentration (MIC) distributions at 2000-4000 µg/mL and 500-1000 µg/ml, respectively. Ampicillin MIC distribution was bimodal with 20% resistant strai...

  20. Diversity and antibiotic resistance of aeromonas spp. in drinking and waste water treatment plants

    OpenAIRE

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

    2011-01-01

    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 ver...

  1. Deficient sumoylation of yeast 2-micron plasmid proteins Rep1 and Rep2 associated with their loss from the plasmid-partitioning locus and impaired plasmid inheritance.

    Directory of Open Access Journals (Sweden)

    Jordan B Pinder

    Full Text Available The 2-micron plasmid of the budding yeast Saccharomyces cerevisiae encodes copy-number amplification and partitioning systems that enable the plasmid to persist despite conferring no advantage to its host. Plasmid partitioning requires interaction of the plasmid Rep1 and Rep2 proteins with each other and with the plasmid-partitioning locus STB. Here we demonstrate that Rep1 stability is reduced in the absence of Rep2, and that both Rep proteins are sumoylated. Lysine-to-arginine substitutions in Rep1 and Rep2 that inhibited their sumoylation perturbed plasmid inheritance without affecting Rep protein stability or two-hybrid interaction between Rep1 and Rep2. One-hybrid and chromatin immunoprecipitation assays revealed that Rep1 was required for efficient retention of Rep2 at STB and that sumoylation-deficient mutants of Rep1 and Rep2 were impaired for association with STB. The normal co-localization of both Rep proteins with the punctate nuclear plasmid foci was also lost when Rep1 was sumoylation-deficient. The correlation of Rep protein sumoylation status with plasmid-partitioning locus association suggests a theme common to eukaryotic chromosome segregation proteins, sumoylated forms of which are found enriched at centromeres, and between the yeast 2-micron plasmid and viral episomes that depend on sumoylation of their maintenance proteins for persistence in their hosts.

  2. Occurrence of potential pathogenic Aeromonas species in tropical seafood, aquafarms and mangroves off Cochin coast in South India

    Directory of Open Access Journals (Sweden)

    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

  3. 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.

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

    Science.gov (United States)

    Starliper, Clifford E; Ketola, Henry G; Noyes, Andrew D; Schill, William B; Henson, Fred G; Chalupnicki, Marc A; Dittman, Dawn E

    2015-01-01

    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. PMID:25685547

  5. Influence of Limonia acidissima L. against the biofilm forming Aeromonas hydrophila isolated from fresh water fishes

    Directory of Open Access Journals (Sweden)

    Srinivasan Ponnuraj

    2015-04-01

    Full Text Available Limonia acidissima is a medicinal plant commonly used for multitude of ailments. In this context, the validation of traditionally used medicinal plant that the fruit extracts of L. acidissima exhibit antibiofilm activity against the predominant fish pathogen Aeromonas hydrophila was assessed. Among ten isolates of Aeromonas spp, KUAH1 showed strong biofilm formation and was studied further. The methanol (LA-M and ethyl acetate (LA-EA fraction of Limonia fruit extract clearly demonstrated significant (p ≤ 0.005 antibiofilm activity of 58 to 94% and 54 to 77% respectively. Furthermore, the potential of Limonia fruit extracts against some of the biofilm associated factors were tested by swimming and swarming motility assay, XTT and anti-haemolytic activity assay. Extracellular protein analysis revealed differential protein expression at molecular weight corresponding to 30-60 kDa. This is the first report on antibiofilm activity of L. acidissima fruit extracts, signifying the scope for development of complementary medicine to treat Aeromonas biofilm-associated infections.

  6. Effectiveness of ultrasound, UV-C, and photocatalysis on inactivation kinetics of Aeromonas hydrophila.

    Science.gov (United States)

    Kaur, Jasjeet; Karthikeyan, Raghupathy; Pillai, Suresh D

    2015-01-01

    In this study, bactericidal effects of 24 kHz ultrasound, ultraviolet (UV-C) irradiation, and titanium dioxide (TiO2) photocatalyst were studied on inactivation of Aeromonas hydrophila, an emerging pathogen listed on the US Environmental Protection Agency's (US EPA) candidate contaminant list. Metabolic activity (using the AlamarBlue dye) assays were performed to assess the residual activity of the microbial cells after the disinfection treatments along with culture-based methods. A faster inactivation rate of 1.52 log min(-1) and inactivation of 7.62 log10 was observed within 5 min of ultrasound exposure. Ultrasound treated cells repaired by 1.4 log10 in contrast to 5.3 log10 repair for UV-C treated cells. Ultrasound treatment significantly lowered the reactivation of Aeromonas hydrophila in comparison to UV-C- and UV-C-induced photocatalysis. Ultrasound appeared to be an effective means of inactivating Aeromonas hydrophila and could be used as a potential disinfection method for water and wastewater reuse. PMID:26301848

  7. 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.

  8. 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

  9. 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.

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

    Science.gov (United States)

    Starliper, Clifford E.; Ketolab, Henry G.; Noyes, Andrew D.; Schill, William B.; Henson, Fred G.; Chalupnicki, Marc A.; Dittman, Dawn E.

    2015-01-01

    Diseases of fishes caused by Aeromonas spp. are common, have broad host ranges and may cause high mortality. Treatments for captive-reared populations using antimicrobials are limited with concerns for bacterial resistance development and environmental dissemination. This study was done to determine if 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 MBC’s (0.02 to 0.04%) were obtained with three different sources of cinnamon oil. MBC’s 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 MBC’s to twelve isolates. A concentration of silver greater than 15 mg/L would be required to determine MBC’s for all but one isolate

  11. 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

  12. Modeling sRNA-regulated Plasmid Maintenance

    CERN Document Server

    Gong, Chen Chris

    2016-01-01

    We study a theoretical model for the toxin-antitoxin (hok/sok) mechanism for plasmid maintenance in bacteria. Toxin-antitoxin systems enforce the maintenance of a plasmid through post-segregational killing of cells that have lost the plasmid. Key to their function is the tight regulation of expression of a protein toxin by an sRNA antitoxin. Here, we focus on the nonlinear nature of the regulatory circuit dynamics of the toxin-antitoxin mechanism. The mechanism relies on a transient increase in protein concentration rather than on the steady state of the genetic circuit. Through a systematic analysis of the parameter dependence of this transient increase, we confirm some known design features of this system and identify new ones: for an efficient toxin-antitoxin mechanism, the synthesis rate of the toxin's mRNA template should be lower that of the sRNA antitoxin, the mRNA template should be more stable than the sRNA antitoxin, and the mRNA-sRNA complex should be more stable than the sRNA antitoxin. Moreover, ...

  13. Determination of Plasmid Segregational Stability in a Growing Bacterial Population.

    Science.gov (United States)

    Kramer, M Gabriela

    2016-01-01

    Bacterial plasmids are extensively used as cloning vectors for a number of genes for academic and commercial purposes. Moreover, attenuated bacteria carrying recombinant plasmids expressing genes with anti-tumor activity have shown promising therapeutic results in animal models of cancer. Equitable plasmid distribution between daughter cells during cell division, i.e., plasmid segregational stability, depends on many factors, including the plasmid copy number, its replication mechanism, the levels of recombinant gene expression, the type of bacterial host, and the metabolic burden associated with all these factors. Plasmid vectors usually code for antibiotic-resistant functions, and, in order to enrich the culture with bacteria containing plasmids, antibiotic selective pressure is commonly used to eliminate plasmid-free segregants from the growing population. However, administration of antibiotics can be inconvenient for many industrial and therapeutic applications. Extensive ongoing research is being carried out to develop stably-inherited plasmid vectors. Here, I present an easy and precise method for determining the kinetics of plasmid loss or maintenance for every ten generations of bacterial growth in culture. PMID:26846807

  14. Plasmid transfer between bacteria in soil microcosms and the field

    Directory of Open Access Journals (Sweden)

    Eric Smit

    1997-01-01

    Full Text Available In ibis review factors influencing conjugal plasmid transfer between bacteria and the possible role of naturally occurring selftransmissible plasmide for the dissemination of recombinant DNA in soil will be discussed. In microcosm studies, plasmid transfer between various species of introduced bacteria has been detected. Moreover, plamid transfer to indigenous soil micoorganisms was observed. Soil is an oligotrophic environment and plasmid transfer occurred mainly under conditions which were nutritionally favourable for bacteria, such as in the plant rhizosphere and in the presence of clay minerais or added nutrients. Mobilizable plasmids, lacking the ability to transfer themselves, have been reported to be transferred in the presence of selftransmissible plasmids. A study comparing conjugal transfer in microcosme with those in the field revealed that the transfer rates found in microcosme and in the field were similar. Transfer of chromosomal DNA by plasmid RP4 could only be shown on filters and was not observed in soil. Transfer of plasmids carrying biodegradative genes appeared to be favoured in the presence of the compound that can be degraded. Evidence was found for the presence of naturally-occurring selftransmissible plasmids in bacteria in the rhizosphere which could mobilize recombinant plasmids.

  15. 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 ...

  16. Mutation in the S-ribosylhomocysteinase (luxS) gene involved in quorum sensing affects biofilm formation and virulence in a clinical isolate of Aeromonas hydrophila

    Science.gov (United States)

    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...

  17. 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...

  18. Characterization of toxin plasmids in Clostridium perfringens type C isolates.

    Science.gov (United States)

    Gurjar, Abhijit; Li, Jihong; McClane, Bruce A

    2010-11-01

    Clostridium perfringens type C isolates cause enteritis necroticans in humans or necrotizing enteritis and enterotoxemia in domestic animals. Type C isolates always produce alpha toxin and beta toxin but often produce additional toxins, e.g., beta2 toxin or enterotoxin. Since plasmid carriage of toxin-encoding genes has not been systematically investigated for type C isolates, the current study used Southern blot hybridization of pulsed-field gels to test whether several toxin genes are plasmid borne among a collection of type C isolates. Those analyses revealed that the surveyed type C isolates carry their beta toxin-encoding gene (cpb) on plasmids ranging in size from ∼65 to ∼110 kb. When present in these type C isolates, the beta2 toxin gene localized to plasmids distinct from the cpb plasmid. However, some enterotoxin-positive type C isolates appeared to carry their enterotoxin-encoding cpe gene on a cpb plasmid. The tpeL gene encoding the large clostridial cytotoxin was localized to the cpb plasmids of some cpe-negative type C isolates. The cpb plasmids in most surveyed isolates were found to carry both IS1151 sequences and the tcp genes, which can mediate conjugative C. perfringens plasmid transfer. A dcm gene, which is often present near C. perfringens plasmid-borne toxin genes, was identified upstream of the cpb gene in many type C isolates. Overlapping PCR analyses suggested that the toxin-encoding plasmids of the surveyed type C isolates differ from the cpe plasmids of type A isolates. These findings provide new insight into plasmids of proven or potential importance for type C virulence. PMID:20823204

  19. Unique type of plasmid maintenance function: postsegregational killing of plasmid-free cells.

    OpenAIRE

    Gerdes, K; Rasmussen, P. B.; Molin, S

    1986-01-01

    The stability locus parB+ of plasmid R1 has been found to specify a unique type of plasmid maintenance function. Two genes, hok (host killing) and sok (suppressor of killing), are required for the stabilizing activity. The hok gene encodes a highly toxic gene product, whose overexpression causes a rapid killing and a concomitant dramatic change in morphology of the host cell. The other gene, sok, was found to encode a product that counteracts the hok gene-mediated killing. The parB+ region wa...

  20. Molecular characterization of "plasmid-free" antibiotic-resistant Haemophilus influenzae.

    OpenAIRE

    Roberts, M C; Smith, A. L.

    1980-01-01

    We examined 14 multiresistant and 8 ampicillin- or tetracycline-resistant Haemophilus influenzae isolates and 4 ampicillin-resistant H. parainfluenzae isolates for plasmid deoxyribonucleic acid. Sixteen strains carried plasmids. Both "plasmid-free" and plasmid-carrying isolates transferred the antibiotic resistance by conjugation. All transconjugants carried plasmid deoxyribonucleic acid, suggesting that the apparent plasmid-free strains contained R plasmids encoding for antibiotic resistance.

  1. Novo meio seletivo-indicador para detecção de Aeromonas e Plesiomonas: ágar UNISC New selective indicator medium for detection of Aeromonas and Plesiomonas: UNISC agar

    Directory of Open Access Journals (Sweden)

    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.

  2. Safety and efficacy of DNA vaccines: Plasmids vs. minicircles

    OpenAIRE

    Stenler, Sofia; Blomberg, Pontus; Smith, Ci Edvard

    2014-01-01

    While DNA vaccination using plasmid vectors is highly attractive, there is a need for further vector optimization regarding safety, stability, and efficiency. In this commentary, we review the minicircle vector (MC), which is an entity devoid of plasmid bacterial sequences, as an alternative to the traditional plasmid construct. The commentary highlights the recent discovery by Stenler et al. (2014) that the small size of an MC enables improved resistance to the shearing forces associated wit...

  3. Pathogenomics of the Virulence Plasmids of Escherichia coli

    OpenAIRE

    Johnson, Timothy J.; Lisa K. Nolan

    2009-01-01

    Summary: Bacterial plasmids are self-replicating, extrachromosomal elements that are key agents of change in microbial populations. They promote the dissemination of a variety of traits, including virulence, enhanced fitness, resistance to antimicrobial agents, and metabolism of rare substances. Escherichia coli, perhaps the most studied of microorganisms, has been found to possess a variety of plasmid types. Included among these are plasmids associated with virulence. Several types of E. col...

  4. Identification of plasmid partition function in coryneform bacteria.

    OpenAIRE

    Kurusu, Y; Satoh, Y.; Inui, M.; Kohama, K; Kobayashi, M.; Terasawa, M.; Yukawa, H

    1991-01-01

    We have identified and characterized a partition function that is required for stable maintenance of plasmids in the coryneform bacteria Brevibacterium flavum MJ233 and Corynebacterium glutamicum ATCC 31831. This function is localized to a HindIII-NspV fragment (673 bp) adjacent to the replication region of the plasmid, named pBY503, from Brevibacterium stationis IFO 12144. The function was independent of copy number control and was not associated directly with plasmid replication functions. ...

  5. Transformation of Bacillus thuringiensis protoplasts by plasmid deoxyribonucleic acid.

    OpenAIRE

    Martin, P A; Lohr, J. R.; Dean, D H

    1981-01-01

    A method has been developed to transform plasmid deoxyribonucleic acid into protoplasts of the insect pathogen Bacillus thuringiensis. Protoplasts were formed by treatment of cells with lysozyme. The efficiency of formation of protoplasts was affected by the strain, the media, and the cell density. Deoxyribonucleic acid uptake was induced by polyethylene glycol. Deoxyribonucleic acid from the Staphylococcus aureus plasmid pC194 was used for transformation. Although this plasmid could not be i...

  6. Streamlined Purification of Plasmid DNA From Prokaryotic Cultures

    OpenAIRE

    Pueschel, Laura; Li, Hongshan; Hymes, Matthew

    2011-01-01

    We describe the complete process of AcroPrep Advance Filter Plates for 96 plasmid preparations, starting from prokaryotic culture and ending with high purity DNA. Based on multi-well filtration for bacterial lysate clearance and DNA purification, this method creates a streamlined process for plasmid preparation. Filter plates containing silica-based media can easily be processed by vacuum filtration or centrifuge to yield appreciable quantities of plasmid DNA. Quantitative analyses determine ...

  7. Comparative genetic organization of incompatibility group P degradative plasmids.

    OpenAIRE

    Burlage, R S; Bemis, L A; Layton, A C; Sayler, G. S.; Larimer, F

    1990-01-01

    Plasmids that encode genes for the degradation of recalcitrant compounds are often examined only for characteristics of the degradative pathways and ignore regions that are necessary for plasmid replication, incompatibility, and conjugation. If these characteristics were known, then the mobility of the catabolic genes between species could be predicted and different catabolic pathways might be combined to alter substrate range. Two catabolic plasmids, pSS50 and pSS60, isolated from chlorobiph...

  8. Temperate bacteriophage ΦO18P from an Aeromonas media isolate: Characterization and complete genome sequence

    International Nuclear Information System (INIS)

    A group of 74 Aeromonas isolates from surface water of three ponds in Bielefeld, Germany was screened for prophage induction after UV irradiation. The phage ΦO18P was induced from the Aeromonas media isolate O18. ΦO18P belongs to the Myoviridae phage family. The complete nucleotide sequence of the double stranded DNA genome of bacteriophage ΦO18P consists of 33,985 bp. The genome has 5' protruding cohesive ends of 16 bases. On the ΦO18P genome 46 open reading frames (orfs) were identified which are organized in the modules integration and regulation, replication, head, packaging, tail and lysis. Additionally the phage DNA includes a methylase gene. Comparison of the genome architecture with those of other bacteriophages revealed significant similarities to the P2 phage family and especially to the prophages of Aeromonas salmonicida and the Vibrio cholerae phage K139

  9. Caracterização de Aeromonas Spp. Isoladas de Águas Não Tratadas para Consumo Humano

    OpenAIRE

    Ribeiro, Maria Ermelinda de Aguiar

    2008-01-01

    O género Aeromonas forma uma unidade monofilética dentro do sub-grupo gama -3 das Proteobactérias. Bactérias do grupo das Aeromonas surgem em diversos ambientes aquáticos. Está também comprovada a presença de Aeromonas spp. em águas para consumo humano, tratadas e não tratadas. Os organismos deste grupo são frequentemente referidos como “patogénicos emergentes” sendo pesquisados obrigatóriamente no Canadá, Itália e Holanda. Assim, pretende-se com este estudo, fazer uma avaliação da presença d...

  10. 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 only. A. salmonicida subsp. salmonicida isolates tested, belonged to group 1. The PCR primer-sets separated A. salmonicida from other reference strains of Aeromonas species and related bacteria with the exception of Aeromonas hydrophila. The results indicated that PCR typing is a useful framework for...

  11. Construction of a eukaryotic expression plasmid of Humanin*

    OpenAIRE

    Luo, Ben-yan; Chen, Xiang-ming; Tang, Min; Chen, Feng; Chen, Zhi

    2004-01-01

    Objective: To construct a eukaryotic expression plasmid pcDNA3.1(-)-Humanin. Methods: The recombinant plasmid pGEMEX-1-Humanin was digested with restriction endonucleases BamH I and Hind III and the Humanin gene fragments, about 100 bp length, were obtained. Then the Humanin gene fragments were inserted into eukaryotic expression vector pcDNA3.1(-) and the recombinant plasmids pcDNA3.1(-)-Humanin were identified by sequencing. Results: Recombinant plasmid DNA successfully produced a band whic...

  12. Characterization of a plasmid from moderately halophilic eubacteria

    OpenAIRE

    Fernández Castillo, Rosario; Vargas, C.; Nieto Gutiérrez, Joaquín José; Ventosa Ucero, Antonio; Ruiz Berraquero, Francisco

    1992-01-01

    A plasmid has been isolated for the first time from moderately halophilic eubacteria. Halomonas elongata, Halomonrrs halmphila, Deleya halophila and Vibrio costkola were found to harbour an 11.5 kbp plasmid (pMH1). The plasmid was isolated and characterized after transformation into Escherichia coh'JM101 cells. A restriction map was constructed, and unique restriction sites for EcoRI, EcoRV and ClaI were detected. The occurrence of such a plasmid in the original halophilic strains was confirm...

  13. Characterization of Chlamydia trachomatis Plasmid-Encoded Open Reading Frames

    OpenAIRE

    Gong, Siqi; Yang, Zhangsheng; Lei, Lei; Shen, Li; Zhong, Guangming

    2013-01-01

    The recent success in transformation of Chlamydia trachomatis represents a major advancement in Chlamydia research. Plasmid-free C. trachomatis serovar L2 organisms can be transformed with chlamydial plasmid-based shuttle vectors pGFP::SW2 and pBRCT. Deletion of plasmid genes coding for Pgp1 to Pgp8 in pBRCT led to the identification of Pgp1, -2, -6, and -8 as plasmid maintenance factors; Pgp4 as a transcriptional regulator of chlamydial virulence-associated gene expression; and Pgp3, -5, and...

  14. Plasmid P1 replication: negative control by repeated DNA sequences.

    OpenAIRE

    Chattoraj, D; Cordes, K.; Abeles, A

    1984-01-01

    The incompatibility locus, incA, of the unit-copy plasmid P1 is contained within a fragment that is essentially a set of nine 19-base-pair repeats. One or more copies of the fragment destabilizes the plasmid when present in trans. Here we show that extra copies of incA interfere with plasmid DNA replication and that a deletion of most of incA increases plasmid copy number. Thus, incA is not essential for replication but is required for its control. When cloned in a high-copy-number vector, pi...

  15. Identification of plasmid partition function in coryneform bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Kurusu, Yasurou; Satoh, Yukie; Inui, Masayuki; Kohama, Keiko; Kobayashi, Miki; Terasawa, Masato; Yukawa, Hideaki (Mitsubishi Petrochemical Co., Ltd., Ibaraki (Japan))

    1991-03-01

    The authors have identified and characterized a partition function that is required for stable maintenance of plasmids in the coryneform bacteria Brevibacterium flavum MJ233 and Corynebacterium glutamicum ATCC 31831. This function is localized to a HindIII-NspV fragment (673 bp) adjacent to the replication region of the plasmid, named pBY503, from Brevibacterium stationis IFO 12144. The function was independent of copy number control and was not associated directly with plasmid replication functions. This fragment was able to stabilize the unstable plasmids in cis but not in trans.

  16. Degradative Plasmid and Heavy Metal Resistance Plasmid Naturally Coexist in Phenol and Cyanide Assimilating Bacteria

    OpenAIRE

    Bahig E.  Deeb; Abdullah D. Altalhi

    2009-01-01

    Problem statement: Heavy metals are known to be powerful inhibitors of xenobiotics biodegradation activities. Alleviation the inhibitory effect of these metals on the phenol biodegradation activities in presence of heavy metals resistant plasmid was investigated. Approach: Combination of genetic systems of degradation of xenobiotic compound and heavy metal resistance was one of the approaches to the creation of polyfunctional strains for bioremediation of s...

  17. Photonic plasmid stability of transformed Salmonella Typhimurium: A comparison of three unique plasmids

    Directory of Open Access Journals (Sweden)

    Lay Donald

    2009-07-01

    Full Text Available Abstract Background Acquiring a highly stable photonic plasmid in transformed Salmonella Typhimurium for use in biophotonic studies of bacterial tracking in vivo is critical to experimental paradigm development. The objective of this study was to determine stability of transformed Salmonella Typhimurium (S. typh-lux using three different plasmids and characterize their respective photonic properties. Results In presence of ampicillin (AMP, S. typh-lux with pCGLS-1, pAK1-lux and pXEN-1 plasmids exhibited 100% photon-emitting colonies over a 10-d study period. Photon emitters of S. typh-lux with pCGLS-1, pAK1-lux and pXEN-1 without AMP selection decreased over time (P 7 to 1 × 109 CFU, P 0.05; although photonic emissions across a range of bacterial concentrations were not different (1 × 104 to 1 × 106 CFU, P > 0.05. For very low density bacterial concentrations imaged in 96 well plates photonic emissions were positively correlated with bacterial concentration (P 3 to 1 × 105 CFU low to high were different in the 96-well plate format (P Conclusion These data characterize photon stability properties for S. typh-lux transformed with three different photon generating plasmids that may facilitate real-time Salmonella tracking using in vivo or in situ biophotonic paradigms.

  18. Photonic Plasmid Stability of Transformed Salmonella Typhimurium: A Comparison of Three Unique Plasmids

    Science.gov (United States)

    Background: Acquiring a highly stable photonic plasmid in transformed Salmonella Typhimurium for use in biophotonic studies of bacterial tracking in vivo is critical to experimental paradigm development. The objective of this study was to determine stability of transformed Salmonella Typhimurium (S....

  19. Photonic plasmid stability of transformed Salmonella typhimurium: A comparison of three unique plasmids

    Science.gov (United States)

    Acquiring a highly stable photonic plasmid in transformed Salmonella typhimurium for use in biophotonic studies of bacterial tracking in vivo is critical to experimental paradigm development. The objective of this study was to determine stability of transformed Salmonella typhimurium (S. typh-lux) u...

  20. Bacterial Mitosis: ParM of Plasmid R1 Moves Plasmid DNA by an Actin-like Insertional Polymerization Mechanism

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette;

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...... act together to generate the force required for plasmid movement during segregation. ParR protein binds cooperatively to the centromeric parC DNA region, thereby forming a complex that interacts with the filament-forming actin-like ParM protein in an ATP-dependent manner, suggesting that plasmid...... movement is powered by insertional polymerization of ParM. Consistently, we find that segregating plasmids are positioned at the ends of extending ParM filaments. Thus, the process of R1 plasmid segregation in E. coli appears to be mechanistically analogous to the actin-based motility operating...

  1. Comparison of ELISA and PCR vis-à-vis cultural methods for detecting Aeromonas spp. in foods of animal origin.

    Science.gov (United States)

    Arora, S; Agarwal, R K; Bist, B

    2006-02-01

    The present study was conducted to assess the best method of the most commonly used methods for detection of aeromonads in foods of animal origin. With this objective an OMP based indirect plate ELISA and a duplex-PCR using primers targeting aerolysin gene and 16S rRNA gene and yielding amplicons of 252 bp and 599 bp, respectively, were standardized. The standardized protocols and the conventional cultural method were then compared for their respective sensitivities and specificities for detecting aeromonads from chicken and milk samples. Both the standardized assays were found to be highly specific for Aeromonas. The efficiency of the standardized indirect-ELISA and duplex-PCR protocols was assessed by artificial inoculation studies with varying concentrations of Aeromonas cells inoculated in chicken and milk samples followed by enrichment in Alkaline Peptone Water supplemented with 10 mg/ml cephalothin (APW-C) for 12 h. The results revealed that indirect-ELISA was able to detect a minimum of 10(3) cells/ml or g of Aeromonas cells in spiked milk and chicken samples, respectively. Whereas, duplex-PCR and cultural method were able to detect as low as 1 cell/ml or g of Aeromonas cells in spiked milk and chicken samples. The developed assays were also tested for their efficiency to detect Aeromonas spp. in naturally contaminated milk and chicken samples. Out of a total 50 milk samples screened for presence of Aeromonas by the three methods viz., indirect-ELISA, duplex-PCR and cultural method only 1 (2%) turned out to be positive showing positive results by all three methods. Similarly, 50 samples of chicken were tested by all three methods. Three samples (6%) turned out to be positive and here again by all the three methods. PMID:16216375

  2. Quinolone resistant Aeromonas spp. as carriers and potential tracers of acquired antibiotic resistance in hospital and municipal wastewater.

    Science.gov (United States)

    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. PMID:26546762

  3. Degradative Plasmid and Heavy Metal Resistance Plasmid Naturally Coexist in Phenol and Cyanide Assimilating Bacteria

    Directory of Open Access Journals (Sweden)

    Bahig E.  Deeb

    2009-01-01

    Full Text Available Problem statement: Heavy metals are known to be powerful inhibitors of xenobiotics biodegradation activities. Alleviation the inhibitory effect of these metals on the phenol biodegradation activities in presence of heavy metals resistant plasmid was investigated. Approach: Combination of genetic systems of degradation of xenobiotic compound and heavy metal resistance was one of the approaches to the creation of polyfunctional strains for bioremediation of soil after co-contamination with organic pollutants and heavy metals. Results: A bacterial strain Pseudomonas putida PhCN (pPhCN1, pPhCN2 had been obtained. This bacterium contained two plasmids, a 120 Kb catabolic plasmid that encode for breakdown of phenol (pPhCN1 and pPhCN2 plasmid (100 Kb that code for cadmium and copper resistant. Cyanide assimilation by this bacterium was encoded by chromosomal genes. The inhibitory effect of cadmium (Cd2+ or copper (Cu2+ on the degradation of phenol and cyanide by P. putida strains PhCN and PhCN1 (contained pPhCN1 were investigated. The resistant strain PhCN showed high ability to degrade phenol and cyanide in presence of Cd2+ or Cu2+ comparing with the sensitive strain PhCN1. In addition, Cd2+ or Cu2+ was also found to exert a strong inhibitory effect on the C23O dioxygenase enzyme activity in the presence of cyanide as a nitrogen source. Conclusion: The presence of heavy metal resistance plasmid alleviated the inhibitory effect of metals on the phenol and cyanide assimilation by resistant strain.

  4. Induced mutagenesis of plasmids and chromosomal genes inserted into plasmid DNA 1. Mutagenic effects of irradiations

    International Nuclear Information System (INIS)

    Effect of two physical agents: UV- and γ-radiation has been considered in comparison. DNA of RSF2124 plasmid, determining colcine synthesis and ampicillin resistance, was used as a model. Mutagenous effect is taken into account according to the appearance of Col--mutants, which are not capable of colicine synthesis. Lethal effect is determined according to ampicillin marker inactivation. After reisolation of plasmid DNA from mutant transformant, new traits and antibiotic resistance are preserved during subsequent transformations and reseedings of transformed colonies, which proves mutational nature of the transformations. Under short-wave UV irradiation (lambda=254 nm) of RSF2124 DNA a clear mutagenous effect is detected: relative amount of Col--mutants at the optimum for mutagenesis doses increased by a factor of 10. Under conditions of W-reactivation (additional UV-irradiation of recipient cells of wild C600 type) of lethal injuries an increase in mutagenous effect was observed, which is reliable for 95%. A distinct increase in mutagenesis (approximately by a factor of 4) is observed during UV-irradiation in small doses of only one recipient cell (a so-called indirect UV-mutagenesis). Thus, according to its ability to W- and indirect UV-mutagenesis plasmid DNA behaves as DNA of moderate phages, which can testify to their evolution relationship. Treatment of plasmid DNA with acridine orange before UV-irradiation protected only from lethal injuries. γ-irradiation of 60Co at inactivation approximately 10-2 increased by an order the yield of Col--mutants. The presence of the plasmid in a cell did not affect its UV-resistance

  5. Identification and Molecular Characterization of the Homogentisate Pathway Responsible for Pyomelanin Production, the Major Melanin Constituents in Aeromonas media WS

    OpenAIRE

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

    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), ty...

  6. DETECTED OF AERO GENE IN AEROMONAS HYDROPHILA ISOLATES FROM SHRIMP AND PEELED SHRIMP SAMPLES IN LOCAL MARKETS

    Directory of Open Access Journals (Sweden)

    Alaa Kareem Niamah

    2012-10-01

    Full Text Available A 62 isolates were isolated from 33 samples of shrimp and peeled shrimp in three local markets in Basrah city. A 36 isolates were identified to be Aeromonas hydrophila bacteria depending on morphological, microscopic examinations and ten biochemical tests. 83.33% (30 isolates from isolates produced ß-haemolysis on tryptone soy agar with 5% sheep blood. Aero gene detection by polymerase chain reaction technique, Theband appearance in the amplified gene of bacteria shows the molecular weight of aerolysin (424 bp. A 100% (36 isolates of Aeromonas hydrophila isolates were contained Aero gene.

  7. Mutations in an antisense RNA, involved in the replication control of a repABC plasmid, that disrupt plasmid incompatibility and mediate plasmid speciation.

    Science.gov (United States)

    Rivera-Urbalejo, América; Pérez-Oseguera, Ángeles; Carreón-Rodríguez, Ofelia E; Cevallos, Miguel A

    2015-03-01

    The maintenance of large plasmid in a wide variety of alpha-proteobacteria depends on the repABC replication/segregation unit. The intergenic repB-repC region of these plasmids encodes a countertranscribed RNA (ctRNA) that modulates the transcription/translation rate of RepC, the initiator protein. The ctRNA acts as a strong incompatibility factor when expressed in trans. We followed a site directed mutagenesis approach to map those sequences of the ctRNA that are required for plasmid incompatibility and for plasmid replication control. We found that the first three nucleotides of the 5'-end of the ctRNA are essential for interactions with its target RNA. We also found that stretches of 4-5 nucleotides of non-complementarity within the first 10 nucleotides of the left arm of the ctRNA and the target RNA are sufficient to avoid plasmid incompatibility. Additionally, miniplasmid derivatives expressing ctRNAs with mutations in the 5' end or small deletions in the ctRNA are capable of controlling their own replication and coexisting with the parental plasmid. We suggest that a mechanism that could have a crucial role in the speciation process of repABC plasmids is to accumulate enough changes in this small region of the ctRNA gene to disrupt heteroduplex formation between the target RNA of one plasmid and the ctRNA of the other. Plasmids carrying these changes will not have defects in their maintenance. PMID:25644116

  8. A foodborne outbreak of Aeromonas hydrophila in a college, Xingyi City, Guizhou, China, 2012

    Directory of Open Access Journals (Sweden)

    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.

  9. Diabetic Foot Due to Aeromonas Hydrophila and Pseudomonas Oryzihabitans: A Case Report

    Directory of Open Access Journals (Sweden)

    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

  10. 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.

  11. Prianjanje bakterije Aeromonas hydrophila na staklene površine modificirane pomoću organosilana

    OpenAIRE

    Kregiel, Dorota

    2013-01-01

    Svrha je ovoga rada bila ispitati svojstvo prianjanja bakterije Aeromonas hydrophila na staklene površine modificirane pomoću silana s četiri vrste reaktivnih skupina, i to: (3-glicidoksipropil) dietoksilana, (3-N,N-dimetil-3-N-n-heksadecilaminopropil) trimetoksisilan klorida, (3-N,N,N-trietanolaminopropil) trimetoksisilan klorida i (3-N-N-dimetil-3-N-n-oktilaminopropil) trimetoksisilan klorida. U radu je korišten soj A. hydrophila LOCK0968, izoliran iz neklorirane vode uzorkovane iz distribu...

  12. 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.

  13. Molecular Cloning of the Tryptophan Operon from an Aeromonas hydrophila Freshwater Isolate

    OpenAIRE

    Anguita, Juan; Rivero, Octavio; Naharro, Germán

    1992-01-01

    A genomic library of Aeromonas hydrophila F9 was constructed by using pBR322 as a vector. From that, two DNA fragments (5.8 and 11.6 kb) were isolated containing genetic information to complement trpA and trpB defects (5.8-kb fragment) and to complement trpA, trpB, trpC, trpD, and trpE defects (11.6-kb fragment) in Escherichia coli mutants. Evidence of the existence of a secondary promoter is given.

  14. Purification and Properties of β-1, 4-Xylanase from Aeromonas caviae W-61

    OpenAIRE

    Viet, Dung Nguyen; Kamio, Yoshiyuki; Abe, Naoki; Kaneko, Jun; Izaki, Kazuo

    1991-01-01

    Aeromonas caviae W-61, which was isolated from water samples at the Faculty of Agriculture, Tohoku University, produced β-1, 4-xylanase (1,4-β-d-xylan xylanohydrolase; EC 3.2.1.8) extracellularly. The xylanase was purified to homogeneity by using DEAE-Sephadex A-50, CM-Sephadex C-50, and Sephadex G-100 column chromatographies. The molecular weight of the purified enzyme was estimated to be 22,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point of the enzyme...

  15. INHIBITION OF Aeromonas hydrophila BY PROBIOTIC STRAINS ISOLATED FROM THE DIGESTIVE TRACT OF Pterophyllum scalare

    OpenAIRE

    M. C. Monroy-Dosta; T. Castro-Barrera; F. J. Fernández-Perrino; L. Mayorga-Reyes

    2010-01-01

    The effect of three dierent probiotic strains of Bacillus (B1, B2 and B3) isolated from the digestive tract of Pterophyllum scalare against Aeromonas hydrophila was evaluated. All the sh that where fed with the dierent probiotic strains obtained higher resistance to the pathogen inoculation since they did not developed any signs of illness nor lesions and they stayed healthy until the end of the experiment, with an observed survival of 100 %. On the other hand, the sh where the probiotic bact...

  16. Construction and Application of R Prime Plasmids, Carrying Different Segments of an Octopine Ti Plasmid from Agrobacterium tumefaciens, for Complementation of vir Genes

    NARCIS (Netherlands)

    Hille, Jacques; Klasen, Ina; Schilperoort, Rob

    1982-01-01

    Several R prime plasmids have been obtained with high efficiency, by enclosing the R plasmid replicator, in an R::Ti cointegrate plasmid, between two copies of the transposon Tn1831, in the same orientation. These R primes carry different segments of an octopine Ti plasmid, and are compatible with T

  17. Production and pharmaceutical formulation of plasmid DNA vaccines

    NARCIS (Netherlands)

    van der Heijden, I.

    2013-01-01

    Research leading to the thesis ‘Production and pharmaceutical formulation of plasmid DNA vaccines‘ can be divided into two parts. The first part describes the development of a Good Manufacturing Practice (GMP) compliant plasmid DNA production process of pDNA vaccines for the treatment of Human papil

  18. Homology of plasmids in strains of unicellular cyanobacteria

    NARCIS (Netherlands)

    Hondel, C.A.M.J.J. van den; Keegstra, W.; Borrias, W.E.; Arkel, G.A. van

    1979-01-01

    Six strains of unicellular cyanobacteria were examined for the presence of plasmids. Analysis of lysates of these strains by CsCl-ethidium bromide density centrifugation yielded a major chromosomal DNA band and a minor band containing covalently closed circular plasmid DNA, as shown by electron micr

  19. Plasmid-encoded copper resistance and precipitation by Mycobacterium scrofulaceum.

    OpenAIRE

    Erardi, F X; Failla, M L; Falkinham, J. O.

    1987-01-01

    A copper-tolerant Mycobacterium scrofulaceum strain was able to remove copper from culture medium by sulfate-dependent precipitation as copper sulfide. Such precipitation of copper sulfide was not observed in a derivative that lacks a 173-kilobase plasmid. In addition, the plasmid-carrying strain has a sulfate-independent copper resistance mechanism.

  20. Two novel conjugative plasmids from a single strain of Sulfolobus

    NARCIS (Netherlands)

    Erauso, G.; Stedman, K.M.; Werken, van de H.J.G.; Zillig, W.; Oost, van der J.

    2006-01-01

    Two conjugative plasmids (CPs) were isolated and characterized from the same 'Sulfolobus islandicus' strain, SOG2/4, The plasmids were separated from each other and transferred into Sulfolobus soltataricus. One has a high copy number and is not stable (pSOG1) whereas the other has a low copy number

  1. Inc A/C Plasmids in Multidrug resistant Salmonella enterica

    Science.gov (United States)

    Bacteria plasmids are fragments of extra-chromosomal double stranded deoxyribonucleic acid (DNA) that can contain a variety of genes beneficial to the survival of the host bacteria. Classification and tracking of plasmids is beneficial because they are potentially a medium of horizontal gene transf...

  2. Transformation of Bacillus subtilis by single-stranded plasmid DNA.

    OpenAIRE

    Rudolph, C F; Schmidt, B J; Saunders, C W

    1986-01-01

    The single-stranded form of a pE194-based plasmid transformed Bacillus subtilis protoplasts at least as efficiently as did the double-stranded plasmid, but the single-stranded form did not detectably transform B. subtilis competent cells.

  3. Curing of the 2 mu DNA plasmid from Saccharomyces cerevisiae.

    OpenAIRE

    Toh-e, A; Wickner, R B

    1981-01-01

    The 2 mu DNA plasmid is often eliminated from yeast cells when they are transformed with the 2 mu DNA-LEU2-pMB9 composite plasmid pJDB219. Since pJDB219 is subsequently lost with high frequency, derivatives lacking all 2 mu DNA can be prepared from any strain.

  4. Purification of large plasmids with methacrylate monolithic columns.

    Science.gov (United States)

    Krajnc, Nika Lendero; Smrekar, Franci; Cerne, Jasmina; Raspor, Peter; Modic, Martina; Krgovic, Danijela; Strancar, Ales; Podgornik, Ales

    2009-08-01

    The rapid evolution of gene therapy and DNA vaccines results in an increasing interest in producing large quantities of pharmaceutical grade plasmid DNA. Most current clinical trials involve plasmids of 10 kb or smaller in size, however, future requirements for multigene vectors including extensive control regions may require the production of larger plasmids, e. g., 20 kb and bigger. The objective of this study was to examine certain process conditions for purification of large plasmids with the size of up to 93 kb. Since there is a lack of knowledge about production and purification of bigger plasmid DNA, cell lysis and storage conditions were investigated. The impact of chromatographic system and methacrylate monolithic column on the degradation of plasmid molecules under nonbinding conditions at different flow rates was studied. Furthermore, capacity measurements varying salt concentration in loading buffer were performed and the capacities up to 13 mg of plasmid per mL of the monolithic column were obtained. The capacity flow independence in the range from 130 to 370 cm/h was observed. Using high resolution monolithic column the separation of linear and supercoiled isoforms of large plasmids was obtained. Last but not least, since the baseline separation of RNA and pDNA was achieved, the one step purification on larger CIM DEAE 8 mL tube monolithic column was performed and the fractions were analyzed by CIM analytical monolithic columns. PMID:19598166

  5. Plasmid DNA induces dodecyl triethyl ammonium bromide to aggregate into vesicle

    Institute of Scientific and Technical Information of China (English)

    Xiang Mei Ran; Xia Guo; Jia Tong Ding

    2012-01-01

    Single-chained cationic surfactant dodecyl triethyl ammonium bromide and plasmid DNA together can form vesicles once the concentration of plasmid DNA reaches a critical value (Ccvc).Bigger the size of plasmid DNA,higher the value of Ccvc.

  6. Antimicrobial activity of some of the south-Indian spices against serotypes of Escherichia coli, Salmonella, Listeria monocytogenes and Aeromonas hydrophila Atividade antimicrobiana de condimentos do sul da India sobre Escherichia coli, Salmonella, Listeria monocytogenes e Aeromonas hydrophila

    OpenAIRE

    M.N. Indu; A.A.M. Hatha; C. Abirosh; U. Harsha; G Vivekanandan

    2006-01-01

    Antibacterial activity of extracts of Allium sativum (garlic), Myristica fragrans (nutmeg), Zingiber officinale (ginger), Allium cepa (onion) and Piper nigrum (pepper) has been evaluated against 20 different serogroups of Escherichia coli, 8 serotypes of Salmonella, Listeria monocytogenes and Aeromonas hydrophila. Garlic extract showed excellent antibacterial activity against all the test organisms, except L. monocytogenes. Nutmeg showed good anti-listerial activity, although activity against...

  7. Construction of a eukaryotic expression plasmid of Humanin

    Institute of Scientific and Technical Information of China (English)

    LUO Ben-yan; CHEN Xiang-ming; TANG Min; CHEN Feng; CHEN Zhi

    2005-01-01

    Objective: To construct a eukaryotic expression plasmid pcDNA3.1 (-)-Humanin. Methods: The recombinant plasm pGEMEX- 1-Humanin was digested with restriction endonucleases BamH I and Hind Ⅲ and the Humanin gene fragments, abo 100 bp length, were obtained. Then the Humanin gene fragments were inserted into eukaryotic expression vector pcDNA3.1 (-) and the recombinant plasmids pcDNA3. l(-)-Humanin were identified by sequencing. Results: Recombinant plasmid DNA succesfully produced a band which had the same size as that of the Humanin positive control. The sequence of recombinant plasmids accorded with the Humnain gene sequence. Conclusions: A eukaryotic expression plasmid of Humanin was successfully constructed.

  8. Permissiveness of soil microbial communities towards broad host range plasmids

    DEFF Research Database (Denmark)

    Klümper, Uli

    of fluorescently tagged conjugative plasmids into a soil microbial community in solid-surface filter matings under maximized cell-to-cell contact, followed by quantification of transfer events through advanced fluorescent microscopy, isolation of transconjugants through triple-gated fluorescent activated cell...... using model BHR plasmid pKJK5 introduced through the γ-proteobacterial donor E. coli. I found that the permissiveness towards plasmids was modified through stress on a taxon specific basis and cannot be generally predicted for the whole community. The response of the phylogenetic group was specific...... between phylogenetically distant groups. Finally, I extended the high-throughput method to quantify the potential of a microbial community to actively mobilize and transfer exogenous mobilizable plasmids to its indigenous members. I evaluated the transfer frequency of model plasmid RSF1010 by comparing...

  9. Radiosensitivity of plasmid DNA: role of topology and concentration

    International Nuclear Information System (INIS)

    Using the plasmid relaxation assay, the induction of single strand breaks (SSB) by ionizing radiation was investigated in two plasmids of different length, pBS and pSP189. The dose-response was linear for both plasmids but pSP189 exhibited a three times higher sensitivity than mBS. This disparity may be explained by a reduced accessibility to hydroxyl radicals due to a different topology of each plasmid, i.e. degree of compaction, as observed with electron microscopy. pBS plasmid was also exposed at various DNA concentrations to γ rays. The yield of SSB decreased with increasing concentration, suggesting a diminution in the amount of hydroxyl radicals efficient for radiolytic attack. This effect of concentration was also observed with densely ionizing radiation. In conclusion, the accessibility of DNA is a key-parameter in the formation of damage in vitro and in vivo as well. (authors)

  10. Positive selection and compensatory adaptation interact to stabilize non-transmissible plasmids

    OpenAIRE

    Millan, A. San; Peña-Miller, R.; Toll-Riera, M.; Halbert, Z. V.; McLean, A R; Cooper, B. S.; Maclean, R. C.

    2014-01-01

    Plasmids are important drivers of bacterial evolution, but it is challenging to understand how plasmids persist over the long term because plasmid carriage is costly. Classical models predict that horizontal transfer is necessary for plasmid persistence, but recent work shows that almost half of plasmids are non-transmissible. Here we use a combination of mathematical modelling and experimental evolution to investigate how a costly, non-transmissible plasmid, pNUK73, can be maintained in popu...

  11. Requirements for the formation of plasmid-transducing particles of Bacillus subtilis bacteriophage SPP1.

    OpenAIRE

    Alonso, J.C.; Lüder, G; Trautner, T A

    1986-01-01

    We had previously proposed that the production of concatemeric plasmid DNA in plasmid-transducing SPP1 particles is a consequence of phage-directed rolling-circle-type replication of plasmid DNA. The production of such DNA was greatly enhanced when DNA/DNA homology was provided between phage and plasmid DNAs (facilitation of transduction). Here we present evidence that synthesis of concatemeric plasmid DNA can proceed after phage infection under conditions non-permissive for plasmid replicati...

  12. Construction of Streptococcus lactis subsp. lactis Strains with a Single Plasmid Associated with Mucoid Phenotype

    OpenAIRE

    von Wright, Atte; Tynkkynen, Soile

    1987-01-01

    Lactose-fermenting mucoid (Lac+ Muc+) variants of plasmid-free Streptococcus lactis subsp. lactis MG1614 were obtained by protoplast transformation with total plasmid DNA from Muc+S. lactis subsp. cremoris ARH87. By using plasmid DNA from these variants for further transformations followed by novobiocininduced plasmid curing, Lac− Muc+ MG1614 strains containing only a single 30-megadalton plasmid could be constructed. This plasmid, designated pVS5, appeared to be associated with the Muc+ phen...

  13. Plasmid stability in immobilized and free recombinant Escherichia coli JM105(pKK223-200): importance of oxygen diffusion, growth rate, and plasmid copy number.

    OpenAIRE

    de Taxis du Poët, P; Arcand, Y; Bernier, R.; Barbotin, J N; Thomas, D.

    1987-01-01

    Stability of the plasmid pKK223-200 in Escherichia coli JM105 was studied for both free and immobilized cells during continuous culture. The relationship between plasmid copy number, xylanase activity, which was coded for by the plasmid, and growth rate and culture conditions involved complex interactions which determined the plasmid stability. Generally, the plasmid stability was enhanced in cultured immobilized cells compared with free-cell cultures. This stability was associated with modif...

  14. Bifurcation Analysis of a Chemostat Model of Plasmid-Bearing and Plasmid-Free Competition with Pulsed Input

    Directory of Open Access Journals (Sweden)

    Zhong Zhao

    2014-01-01

    to the stability of the boundary periodic solution. By use of standard techniques of bifurcation theory, the periodic oscillations in substrate, plasmid-bearing, and plasmid-free organisms are shown when some conditions are satisfied. Our results can be applied to control bioreactor aimed at producing commercial producers through genetically altered organisms.

  15. Development and efficacy of novobiocin and rifampicin-resistant Aeromonas hydrophila as novel vaccines in channel catfish and Nile tilapia

    Science.gov (United States)

    Three attenuated Aeromonas hydrophila vaccines were developed from the virulent 2009 West Alabama isolates through selection for resistance to both novobiocin and rifampicin. When channel catfish (Ictalurus punctatus) were IP injected with 4×105 colony-forming units (CFU) of the mutants, no fish die...

  16. Construction, expression and characterization of eleven putative flagellar apparatus genes of Aeromonas hydrophila AL09-73

    Science.gov (United States)

    Aeromonas hydrophila is ubiquitous in aquatic environments worldwide and is responsible for many human and fish diseases. The genome sequence of A. hydrophila is available in the GenBank database. Our ultimate goal is to develop the whole genome protein arrays of A. hydrophila. In this study, we ...

  17. 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...

  18. Complete Genome Sequence and Methylome Analysis of Aeromonas hydrophila Strain YL17, Isolated from a Compost Pile.

    Science.gov (United States)

    Lim, Yan-Lue; Roberts, Richard J; Ee, Robson; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    In this report, we announce the complete genome sequence of Aeromonas hydrophila strain YL17. Single-molecule real-time (SMRT) DNA sequencing was used to generate the complete genome sequence and the genome-wide DNA methylation profile of this environmental isolate. A total of five unique DNA methyltransferase recognition motifs were reported here. PMID:26941143

  19. Simultaneous Detection of Bacterial Fish Pathogens, Edwardsiella ictaluri, Flavobacterium columnnare and Aeromonas Hydrophila by Multiplex-PCR

    Science.gov (United States)

    Edwardsiella ictaluri, Flavobacterium columnare and Aeromonas hydrophila are three major bacterial pathogens of fish that cause diseases with significant economic impact on the aquaculture industry world-wide. Rapid detection of multiple infections with these bacteria in the same host is important f...

  20. 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...

  1. Virulence of Aeromonas hydrophila to channel catfish Ictalurus punctatus fingerlings in the presence and absence of bacterial extracellular products

    Science.gov (United States)

    Virulence of three 2009 West Alabama isolates (AL09-71, AL09-72, and AL09-73) of Aeromonas hydrophila in the presence or absence of extracellular products (ECP) from overnight bacterial culture to channel catfish fingerlings (4.6 +/- 1.3g) was investigated by both bath immersion and intraperitoneal ...

  2. An in vitro screening method to evaluate chemicals as potential chemotherapeutants to control Aeromonas hydrophila infection in channel catfish

    Science.gov (United States)

    Aeromonas hydrophila, a Gram-negative motile bacillus widely distributed in aquatic environments, is a causative agent of motile aeromonad septicaemia (MAS). Although usually considered as a secondary pathogen associated with disease outbreaks, A. hydrophila could also become a primary pathogen, cau...

  3. 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...

  4. 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...

  5. 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.

  6. 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; Raida, Martin Kristian

    2012-01-01

    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...

  7. 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 of...

  8. 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

    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 furun...

  9. 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. PMID:27044300

  10. Role of MshQ in MSHA pili biosynthesis and biofilm formation of Aeromonas hydrophila.

    Science.gov (United States)

    Qin, Y X; Yan, Q P; Mao, X X; Chen, Z; Su, Y Q

    2014-01-01

    Biofilm formation of pathogen bacterium is currently one of the most widely studied topics; however, little is known regarding pathogen bacteria biofilms in aquaculture. Aeromonas hydrophila is a representative species of the genus Aeromonas, which has been recognized as a common pathogen, is associated with many diseases in aquatic animals, and causes significant mortality. The objectives of this study are i) to confirm that A. hydrophila can form biofilms on abiotic substrates and construct a biofilm growth curve for this bacterium; ii) to identify the genes that play crucial roles in A. hydrophila biofilm formation. The biofilm growth curve of A. hydrophila was constructed using a crystal violet assay, which showed that biofilm formation for this bacterium is a dynamic process. Next, a mutant library of pathogenic A. hydrophila B11 was constructed using the mini-Tn10 transposon mutagenesis system. A total of 861 mutants were screened, and 5 mutants were stably deficient in biofilm formation. Molecular analysis of the mutant B112 revealed that the open reading frame that encodes the protein MshQ was disrupted. Comparison of biological characteristics including growth, motility, and adhesion between the mutant B112 and the wild-type strain B11 suggested that MshQ is necessary for mannose-sensitive hemagglutinin pilus biosynthesis of A. hydrophila, and that these pili play crucial roles in A.hydrophila adherence to a solid surface during the early stages of biofilm formation. PMID:25366789

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

    Science.gov (United States)

    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.

  12. 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.

  13. Bioremediation and Detoxification of Synthetic Wastewater Containing Triarylmethane Dyes by Aeromonas hydrophila Isolated from Industrial Effluent.

    Science.gov (United States)

    Ogugbue, Chimezie Jason; Sawidis, Thomas

    2011-01-01

    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. PMID:21808740

  14. 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.

  15. Nonribosomal peptide synthetase with a unique iterative-alternative-optional mechanism catalyzes amonabactin synthesis in Aeromonas.

    Science.gov (United States)

    Esmaeel, Qassim; Chevalier, Mickael; Chataigné, Gabrielle; Subashkumar, Rathinasamy; Jacques, Philippe; Leclère, Valérie

    2016-10-01

    Based on the exploration of data generated by genome sequencing, a bioinformatics approach has been chosen to identify the biosynthetic pathway of the siderophores produced by Aeromonas species. The amonabactins, considered as a virulence factor, represent a family of four variants of catechol peptidic siderophores containing Dhb, Lys, Gly, and an aromatic residue either Trp or Phe in a D-configuration. The synthesis operon is constituted of seven genes named amoCEBFAGH and is iron-regulated. The cluster includes genes encoding proteins involved in the synthesis and incorporation of the Dhb monomer, and genes encoding specific nonribosomal peptide synthetases, which are responsible for the building of the peptidic moiety. The amonabactin assembly line displays a still so far not described atypical mode of synthesis that is iterative, alternative, and optional. A disruption mutant in the adenylation domain of AmoG was unable to synthesize any amonabactin and to grow in iron stress conditions while a deletion of amoH resulted in the production of only two over the four forms. The amo cluster is widespread among most of the Aeromonas species, only few species produces the enterobactin siderophore. PMID:27531515

  16. 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 the...... biochemical identification of atypical Aer. salmonicida before and after standardization of media and methods. Five laboratories examined 25 isolates of Aer. salmonicida from diverse fish species and geographical locations including the reference strains of Aer. salmonicida subsp, salmonicida (NCMB 1102) and...... reactions. After standardization, improvement was obtained with the identification; however, disagreement was still observed between the different laboratories. These findings demonstrate the difficulties involved in a proper identification of atypical Aer. salmonicida and also that data presented in the...

  17. Plasmid Copy Number Determination by Quantitative Polymerase Chain Reaction.

    Science.gov (United States)

    Anindyajati; Artarini, A Anita; Riani, Catur; Retnoningrum, Debbie S

    2016-01-01

    Recombinant therapeutic proteins are biopharmaceutical products that develop rapidly for years. Recombinant protein production in certain hosts requires vector expression harboring the gene encoding the corresponding protein. Escherichia coli is the prokaryote organism mostly used in recombinant protein production, commonly using a plasmid as the expression vector. Recombinant protein production is affected by plasmid copy number harboring the encoded gene, hence the determination of plasmid copy number also plays an important role in establishing a recombinant protein production system. On the industrial scale, a low copy number of plasmids are more suitable due to their better stability. In the previous study we constructed pCAD, a plasmid derived from the low copy number pBR322 plasmid. This study was aimed to confirm pCAD's copy number by quantitative polymerase chain reaction (qPCR). Plasmid copy number was determined by comparing the quantification signal from the plasmid to those from the chromosome. Copy number was then calculated by using a known copy number plasmid as a standard. Two pairs of primers, called tdk and ori, were designed for targeting a single gene tdk in the chromosome and a conserved domain in the plasmid's ori, respectively. Primer quality was analyzed in silico using PrimerSelect DNASTAR and PraTo software prior to in vitro evaluation on primer specificity and efficiency as well as optimization of qPCR conditions. Plasmid copy number determination was conducted on E. coli lysates harboring each plasmid, with the number of cells ranging from 10(2)-10(5) cells/μL. Cells were lysed by incubation at 95ºC for 10 minutes, followed by immediate freezing at -4°C. pBR322 plasmid with the copy number of ~19 copies/cell was used as the standard, while pJExpress414-sod plasmid possessing the high copy number pUC ori was also determined to test the method being used. In silico analysis based on primer-primer and primer-template interactions showed

  18. An updated view of plasmid conjugation and mobilization in Staphylococcus.

    Science.gov (United States)

    Ramsay, Joshua P; Kwong, Stephen M; Murphy, Riley J T; Yui Eto, Karina; Price, Karina J; Nguyen, Quang T; O'Brien, Frances G; Grubb, Warren B; Coombs, Geoffrey W; Firth, Neville

    2016-01-01

    The horizontal gene transfer facilitated by mobile genetic elements impacts almost all areas of bacterial evolution, including the accretion and dissemination of antimicrobial-resistance genes in the human and animal pathogen Staphylococcus aureus. Genome surveys of staphylococcal plasmids have revealed an unexpected paucity of conjugation and mobilization loci, perhaps suggesting that conjugation plays only a minor role in the evolution of this genus. In this letter we present the DNA sequences of historically documented staphylococcal conjugative plasmids and highlight that at least 3 distinct and widely distributed families of conjugative plasmids currently contribute to the dissemination of antimicrobial resistance in Staphylococcus. We also review the recently documented "relaxase-in trans" mechanism of conjugative mobilization facilitated by conjugative plasmids pWBG749 and pSK41, and discuss how this may facilitate the horizontal transmission of around 90% of plasmids that were previously considered non-mobilizable. Finally, we enumerate unique sequenced S. aureus plasmids with a potential mechanism of mobilization and predict that at least 80% of all non-conjugative S. aureus plasmids are mobilizable by at least one mechanism. We suggest that a greater research focus on the molecular biology of conjugation is essential if we are to recognize gene-transfer mechanisms from our increasingly in silico analyses. PMID:27583185

  19. Plasmid-associated sensitivity of Bacillus thuringiensis to UV light

    International Nuclear Information System (INIS)

    Spores and vegetative cells of Bacillus thuringiensis were more sensitive to UV light than were spores or cells of plasmid-cured B. thuringiensis strains or of the closely related Bacillus cereus. Introduction of B. thuringiensis plasmids into B. cereus by cell mating increased the UV sensitivity of the cells and spores. Protoxins encoded by one or more B. thuringiensis plasmids were not involved in spore sensitivity, since a B. thuringiensis strain conditional for protoxin accumulation was equally sensitive at the permissive and nonpermissive temperatures. In addition, introduction of either a cloned protoxin gene, the cloning vector, or another plasmid not containing a protoxin gene into a plasmid-cured strain of B. thuringiensis all increased the UV sensitivity of the spores. Although the variety of small, acid-soluble proteins was the same in the spores of all strains examined, the quantity of dipicolinic acid was about twice as high in the plasmid-containing strains, and this may account for the differences in UV sensitivity of the spores. The cells of some strains harboring only B. thuringiensis plasmids were much more sensitive than cells of any of the other strains, and the differences were much greater than observed with spores

  20. Investigation of plasmid-induced growth defect in Pseudomonas putida.

    Science.gov (United States)

    Mi, Jia; Sydow, Anne; Schempp, Florence; Becher, Daniela; Schewe, Hendrik; Schrader, Jens; Buchhaupt, Markus

    2016-08-10

    Genetic engineering in bacteria mainly relies on the use of plasmids. But despite their pervasive use for physiological studies as well as for the design and optimization of industrially used production strains, only limited information about plasmid induced growth defects is available for different replicons and organisms. Here, we present the identification and characterization of such a phenomenon for Pseudomonas putida transformants carrying the pBBR1-derived plasmid pMiS1. We identified the kanamycin resistance gene and the transcription factor encoding rhaR gene to be causal for the growth defect in P. putida. In contrast, this effect was not observed in Escherichia coli. The plasmid-induced growth defect was eliminated after introduction of a mutation in the plasmid-encoded rep gene, thus enabling construction of the non-toxic variant pMiS4. GFP reporters construct analyses and qPCR experiments revealed a distinctly lowered plasmid copy number for pMiS4, which is probably the reason for alleviation of the growth defect by this mutation. Our work expands the knowledge about plasmid-induced growth defects and provides a useful low-copy pBBR1 replicon variant. PMID:27287537

  1. Sociobiological control of plasmid copy number in bacteria.

    Directory of Open Access Journals (Sweden)

    Mukta M Watve

    Full Text Available All genes critical for plasmid replication regulation are located on the plasmid rather than on the host chromosome. It is possible therefore that there can be copy-up "cheater" mutants. In spite of this possibility, low copy number plasmids appear to exist stably in host populations. We examined this paradox using a multilevel selection model. Simulations showed that, a slightly higher copy number mutant could out-compete the wild type. Consequently, another mutant with still higher copy number could invade the first invader. However, the realized benefit of increasing intra-host fitness was saturating whereas that of inter-host fitness was exponential. As a result, above a threshold, intra-host selection was overcompensated by inter-host selection and the low copy number wild type plasmid could back invade a very high copy number plasmid. This led to a rock-paper-scissor (RPS like situation that allowed the coexistence of plasmids with varied copy numbers. Furthermore, another type of cheater that had lost the genes required for conjugation but could hitchhike on a conjugal plasmid, could further reduce the advantage of copy-up mutants. These sociobiological interactions may compliment molecular mechanisms of replication regulation in stabilizing the copy numbers.

  2. 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.

  3. Characterization of susceptibility and carrier status of burbot, Lota lota (L.), to IHNV, IPNV, Flavobacterium psychrophilum, Aeromonas salmonicida, and Renibacterium salmoninarum

    Science.gov (United States)

    In this study, susceptibility and potential carrier status of burbot, Lota lota, were assessed for five important fish pathogens. Burbot demonstrated susceptibility and elevated mortality following challenge with infectious haematopoietic necrosis virus (IHNV) by immersion and to Aeromonas salmonici...

  4. Separation of plasmid DNA topoisomers by multimodal chromatography.

    Science.gov (United States)

    Silva-Santos, A Rita; Alves, Cláudia P A; Prazeres, Duarte Miguel F; Azevedo, Ana M

    2016-06-15

    The ability to analyze the distribution of topoisomers in a plasmid DNA sample is important when evaluating the quality of preparations intended for gene therapy and DNA vaccination or when performing biochemical studies on the action of topoisomerases and gyrases. Here, we describe the separation of supercoiled (sc) and open circular (oc) topoisomers by multimodal chromatography. A medium modified with the ligand N-benzyl-N-methyl ethanolamine and an elution scheme with increasing NaCl concentration are used to accomplish the baseline separation of sc and oc plasmid. The utility of the method is demonstrated by quantitating topoisomers in a purified plasmid sample. PMID:27033004

  5. Linearization of donor DNA during plasmid transformation in Neisseria gonorrhoeae.

    OpenAIRE

    Biswas, G D; Burnstein, K. L.; Sparling, P F

    1986-01-01

    We examined the fate of plasmid DNA after uptake during transformation in Neisseria gonorrhoeae. An 11.5-kilobase plasmid, pFA10, was processed to linear double-stranded DNA during uptake by competent cells, but cleavage of pFA10 was not site specific. A minority of pFA10 entered as open circles. A 42-kilobase plasmid, pFA14, was degraded into small fragments during uptake; no intracellular circular forms of pFA14 were evident. Since pFA10 DNA linearized by a restriction enzyme was not furthe...

  6. Living in an Extremely Polluted Environment: Clues from the Genome of Melanin-Producing Aeromonas salmonicida subsp. pectinolytica 34melT

    OpenAIRE

    Pavan, María Elisa; Pavan, Esteban E.; López, Nancy I.; Levin, Laura; Pettinari, M. Julia

    2015-01-01

    Aeromonas salmonicida subsp. pectinolytica 34melT can be considered an extremophile due to the characteristics of the heavily polluted river from which it was isolated. While four subspecies of A. salmonicida are known fish pathogens, 34melT belongs to the only subspecies isolated solely from the environment. Genome analysis revealed a high metabolic versatility, the capability to cope with diverse stress agents, and the lack of several virulence factors found in pathogenic Aeromonas. The mos...

  7. The disulfide bond in the Aeromonas hydrophila lipase/acyltransferase stabilizes the structure but is not required for secretion or activity.

    OpenAIRE

    Brumlik, M J; van der Goot, F. G.; Wong, K R; Buckley, J T

    1997-01-01

    Vibrio and Aeromonas spp. secrete an unusual 35-kDa lipase that shares several properties with mammalian lecithin-cholesterol acyltransferase. The Aeromonas hydrophila lipase contains two cysteine residues that form an intramolecular disulfide bridge. Here we show that changing either of the cysteines to serine does not reduce enzymatic activity, indicating that the disulfide bond is not required for correct folding. However, when either of the cysteines is replaced, the enzyme is more readil...

  8. Plasmid pGA1 from Corynebacterium glutamicum codes for a gene product that positively influences plasmid copy number.

    OpenAIRE

    Nesvera, J; Pátek, M; Hochmannová, J; Abrhámová, Z; Becvárová, V; Jelínkova, M; Vohradský, J

    1997-01-01

    The complete nucleotide sequence (4,826 bp) of the cryptic plasmid pGA1 from Corynebacterium glutamicum was determined. DNA sequence analysis revealed four putative coding regions (open reading frame A [ORFA], ORFA2, ORFB, and ORFC). ORFC was identified as a rep gene coding for an initiator of plasmid replication (Rep) according to the high level of homology of its deduced amino acid sequence with the Rep proteins of plasmids pSR1 (from C. glutamicum) and pNG2 (from Corynebacterium diphtheria...

  9. Cloning and Analysis of a Large Plasmid pBMB165 from Bacillus thuringiensis Revealed a Novel Plasmid Organization

    OpenAIRE

    Yueying Wang; Donghai Peng; Zhaoxia Dong; Lei Zhu; Suxia Guo; Ming Sun

    2013-01-01

    In this study, we report a rapid cloning strategy for large native plasmids via a contig linkage map by BAC libraries. Using this method, we cloned a large plasmid pBMB165 from Bacillus thuringiensis serovar tenebrionis strain YBT-1765. Complete sequencing showed that pBMB165 is 77,627 bp long with a GC-content of 35.36%, and contains 103 open reading frames (ORFs). Sequence analysis and comparison reveals that pBMB165 represents a novel plasmid organization: it mainly consists of a pXO2-like...

  10. A series of template plasmids for Escherichia coli genome engineering.

    Science.gov (United States)

    Deb, Shalini S; Reshamwala, Shamlan M S; Lali, Arvind M

    2016-06-01

    Metabolic engineering strategies often employ multi-copy episomal vectors to overexpress genes. However, chromosome-based overexpression is preferred as it avoids the use of selective pressure and reduces metabolic burden on the cell. We have constructed a series of template plasmids for λ Red-mediated Escherichia coli genome engineering. The template plasmids allow construction of genome integrating cassettes that can be used to integrate single copies of DNA sequences at predetermined sites or replace promoter regions. The constructed cassettes provide flexibility in terms of expression levels achieved and antibiotics used for selection, as well as allowing construction of marker-free strains. The modular design of the template plasmids allows replacement of genetic parts to construct new templates. Gene integration and promoter replacement using the template plasmids are illustrated. PMID:27071533

  11. Construction and Identification of Plasmid pTA-TUB2

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    An about 1.40 Kb target gene fragment was yielded by PCR amplification with the plasmid pRB 129,which was identified by restriction enzyme digestion that the PCR product was TU B2 gene.The gene was digested by the restriction enzyme and was linked with pTA plasmid to construct pTA-TU B2 plasmid.The plasmid was transformed into Chaetomium spp.by PEG method and the transformation rate was 27/(2×105) and it is nine times higher than that of pRB 129.The transformants can grow on the PDA containing 1 000 μg*mL-1 carbendazim,which is 1 000 times higher than the original Chaetomium spp.The resistance was stable after 10 times transfer on non-selective medium.

  12. Characterization of Nocardia Plasmid pXT107

    Institute of Scientific and Technical Information of China (English)

    Hai-Yang XIA; Yong-Qiang TIAN; Ran ZHANG; Kai-Chun LIN; Zhong-Jun QIN

    2006-01-01

    Nocardia, Rhodococcus and Streptornyces, all members of the actinomycetes family, are Gram-positive eubacteria with high G+C content and able to form mycelium. We report here a newly identified plasmid pXT107 of Nocardia sp. 107, one of the smallest circular plasmids found in Nocardia.The complete nucleotide sequence of pXT107 consisted of 4335 bp with 65% G+C content, and encoded one replication extragenic palindromic (Rep) and six hypothetical proteins. The Rep, double-strand origin and single-strand origin of pXT107 resembled those of typical rolling-circle-replication plasmids, such as pNI100 of Nocardia, pRE8424 of Rhodococcus and plJ101 of Streptomyces. The Escherichia coli-Nocardia shuttle plasmid pHAQ22, containing thc rep gene of pXT107, is able to propagate in Nocardia but not in Streptomyces.

  13. Plasmid DNA labelled with 14C or 3H

    International Nuclear Information System (INIS)

    Plasmid DNA labelled with 14C or 3H in thymine was isolated from the thymine-dependent strain of Escherichia coli 15 SPT bacteria. The specific activity of the plasmid DNA preparations lay in the range from 0.5 to 20 MBq/mg, their relative molecular weight was 1.7 x 106 dalton. Molecular weight, preparation purity, and the degree of damage of the plasmid DNA molecules were examined by UV absorption spectroscopy, by gel electrophoresis, and by electron micrography. The quality of the [thymine-2-14C] plasmid DNA was verified in a diagnostic test for the determination of the anti-dsDNA bonding activity in human serum. (author). 1 tab., 5 figs., 30 refs

  14. Characterization of the Double-Partitioning Modules of R27: Correlating Plasmid Stability with Plasmid Localization

    OpenAIRE

    Trevor D Lawley; Taylor, Diane E.

    2003-01-01

    Plasmid R27 contains two independent partitioning modules, designated Par1 and Par2, within transfer region 2. Par1 is member of the type I partitioning family (Walker-type ATPase), and Par2 is a member of the type II partitioning family (actin-type ATPase). Stability tests of cloned Par1 and Par2 and insertional disruptions of Par1 and Par2 within R27 demonstrated that Par1 is the major stability determinant whereas Par2 is the minor stability determinant. Creation of double-partitioning mut...

  15. The Salmonella typhimurium virulence plasmid encodes a positive regulator of a plasmid-encoded virulence gene.

    OpenAIRE

    Caldwell, A L; Gulig, P A

    1991-01-01

    The 90-kb virulence plasmid of Salmonella typhimurium is necessary for invasion beyond the Peyer's patches to the mesenteric lymph nodes and spleens of orally inoculated mice. Two Tn5 insertions located on the left side of a previously identified 14-kb virulence region (P. A. Gulig and R. Curtiss III, Infect. Immun. 58:3262-3271, 1988) and mapping 272 bp from each other exhibited opposite effects on splenic infection of mice after oral inoculation. spvR23::Tn5 decreased splenic infection by 1...

  16. Comparative analysis of conjugative plasmids mediating gentamicin resistance in Staphylococcus aureus.

    OpenAIRE

    Goering, R. V.; Ruff, E A

    1983-01-01

    Five gentamicin-resistant clinical isolates of Staphylococcus aureus were found to contain self-transmissible plasmids of 32 to 37 megadaltons in size. Restriction endonuclease digests of the plasmids were markedly similar to those of reference plasmids of unrelated geographical origin, thus suggesting the significant contribution of common conjugal plasmids to the emergence of gentamicin resistance in S. aureus populations.

  17. Detection of plasmid deoxyribonucleic acid in an isolate of Lactobacillus acidophilus.

    OpenAIRE

    Klaenhammer, T R; Sutherland, S M

    1980-01-01

    Eight strains of Lactobacillus acidophilus were examined for the presence of plasmid deoxyribonucleic acid, and one, a pig intestinal isolate, showed the presence of a 13.7- and a 6.3-megadalton plasmid. This is the first reported evidence for plasmid deoxyribonucleic acid in Lactobacillus acidophilus. The functions of these plasmids are presently unknown.

  18. Pharmaceutical development of the plasmid DNA vaccine pDERMATT

    OpenAIRE

    Quaak, S.G.L.

    2009-01-01

    The discovery of tumor specific antigens and self tolerance mechanisms against these antigens led to the assumption that antigens circulating at sufficient concentration levels could break this self tolerance mechanism and evoke immunological antitumor effects. pDERMATT (plasmid DNA encoding recombinant MART-1 and tetanus toxin fragment-c) is a plasmid that encodes for MART-1, a melanoma associated antigen that is expressed in a large fraction of melanomas. In animal models administration of ...

  19. A novel chromatographic procedure for purification of bacterial plasmids.

    Science.gov (United States)

    Bywater, M; Bywater, R; Hellman, L

    1983-07-01

    A new, rapid procedure for purifying bacterial plasmids with high recovery is described. The sequence of operations consists essentially of treatment with alkali, ribonuclease, and proteinase K, followed by chisam extraction and gel filtration on Sephacryl S-1000, and finally a precipitation step using isopropanol at room temperature. The method gives rather good yields of plasmid DNA of high purity, and lends itself to scaling up. PMID:6312836

  20. Isolation and properties of plasmids from Deinococcus radiodurans Sark

    International Nuclear Information System (INIS)

    Radioresistant bacterium, Deinococcus radiodurans, can repair completely almost all of DNA damages including double strand breaks induced by gamma-rays up to about 5 kGy. In order to reveal the repair mechanism, it is necessary to develop a cloning vector available for the genetic analysis. We tried to isolate plasmids from D.radiodurans Sark strain. In the present paper the isolation and properties of plasmids were described. (author)

  1. Construction of a bioluminescence reporter plasmid for Francisella tularensis

    OpenAIRE

    Bina, Xiaowen R.; Miller, Mark A.; James E Bina

    2010-01-01

    A Francisella tularensis shuttle vector that constitutively expresses the Photorhabdus luminescens lux operon in type A and type B strains of F. tularensis was constructed. The bioluminescence reporter plasmid was introduced into the live vaccine strain of F. tularensis and used to follow F. tularensis growth in a murine intranasal challenge model in real time by bioluminescence imaging. The results show that the new bioluminescence reporter plasmid represents a useful tool for tularemia rese...

  2. Conjugative plasmid transfer from Enterococcus faecalis to Escherichia coli.

    OpenAIRE

    Trieu-Cuot, P; Carlier, C; Courvalin, P

    1988-01-01

    The possibility of transfer of genetic information by conjugation from gram-positive to gram-negative bacteria was investigated with a pBR322-pAM beta 1 chimeric plasmid, designated pAT191. This shuttle vector, which possesses the tra functions of the streptococcal plasmid pAM beta 1, was conjugatively transferred from Enterococcus faecalis to Escherichia coli with an average frequency of 5 x 10(-9) per donor colony formed after mating.

  3. Construction and Characterization of DNA Vaccine for Major Outer Membrane Protein Gene of Aeromonas hydrophila%嗜水气单胞菌外膜蛋白基因 DNA 疫苗载体的构建及分析

    Institute of Scientific and Technical Information of China (English)

    李盼; 李素一; 吴唯维; 林天龙; 林晨韬; 陈叙

    2013-01-01

    为构建嗜水气单胞菌的 DNA 疫苗载体,根据已发表的该菌外膜蛋白基因 momp 的核苷酸序列设计一对特异性引物,应用 PCR 技术,扩增到嗜水气单胞菌 L316的主要外膜蛋白基因,并插入到真核表达载体 pcDNA3上,构建成 DNA 疫苗,命名为 pcDNA3-POMP 。以纯化的原核表达蛋白 GST-POMP 免疫 SD 大鼠制备抗血清,用 ELISA 测定抗体效价达到1∶100000以上;用 pcDNA3-POM P 质粒转染293细胞,转染48 h 后收集细胞,提取细胞的 RNA 进行 RT-PCR ,检测到外源基因的表达。至此,初步完成嗜水气单胞菌 DNA 疫苗表达载体的构建,为进一步疫苗免疫和效价的检测奠定基础。%For constructing the DNA vaccine , a pair of specific PCR primers were designed according to the nucleotide sequence of Aeromonas hydrophila major outer membrane protein gene published by our lab previously . The PCR products were inserted into the eukaryotic expression vector pcDNA 3 to construct a DNA vaccine named pcDNA3-POMP . SD rats were immunized with purified prokaryotic-expressed protein GST-POMP to make antiserum ,whose antibody titer ,measured by ELISA ,was over 1 ∶ 100 000 .293 cells were transfected with pcDNA3-POMP ,48 hours after transfection ,the cells were collected for total RNA extraction and RT-PCR ,and the expression of exogenous momp were detected .Therefore ,we have constructed a plasmid of DNA vaccine for Aeromonas hydrophila ,vaccination and evaluation of this DNA vaccine will be studied in the future .

  4. 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.

  5. Crystallization and initial X-ray analysis of polyhydroxyalkanoate granule-associated protein from Aeromonas hydrophila

    International Nuclear Information System (INIS)

    The phasin PhaPAh from A. hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Polyhydroxyalkanoate (PHA) granule-associated proteins (phasins) were discovered in PHA-accumulating bacteria. They play a crucial role as a structural protein during initial PHA-granule formation and granule growth and also serve as interfaces for granule stabilization in vivo. The phasin PhaPAh from Aeromonas hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Single crystals were cryocooled for X-ray diffraction analysis. The phasin crystals belonged to space group P212121, with unit-cell parameters a = 80.8, b = 108.9, c = 134.4 Å

  6. Expression of Aeromonas caviae ST pyruvate dehydrogenase complex components mediate tellurite resistance in Escherichia coli

    International Nuclear Information System (INIS)

    Potassium tellurite (K2TeO3) is harmful to most organisms and specific mechanisms explaining its toxicity are not well known to date. We previously reported that the lpdA gene product of the tellurite-resistant environmental isolate Aeromonas caviae ST is involved in the reduction of tellurite to elemental tellurium. In this work, we show that expression of A. caviae ST aceE, aceF, and lpdA genes, encoding pyruvate dehydrogenase, dihydrolipoamide transacetylase, and dihydrolipoamide dehydrogenase, respectively, results in tellurite resistance and decreased levels of tellurite-induced superoxide in Escherichia coli. In addition to oxidative damage resulting from tellurite exposure, a metabolic disorder would be simultaneously established in which the pyruvate dehydrogenase complex would represent an intracellular tellurite target. These results allow us to widen our vision regarding the molecular mechanisms involved in bacterial tellurite resistance by correlating tellurite toxicity and key enzymes of aerobic metabolism.

  7. Transcriptome profiling of grass carp (Ctenopharyngodon idellus) infected with Aeromonas hydrophila.

    Science.gov (United States)

    Yang, Ying; Yu, Hui; Li, Hua; Wang, Anli

    2016-04-01

    Aeromonas hydrophila is the causative pathogen of intestinal hemorrhage which has caused great economic loss in grass carp aquaculture. In order to understand the immunological response of grass carp to infection by A. hydrophila, the transcriptomic profiles of the spleens from infected and non-infected grass carp groups were obtained using HiSeq™ 2500 (Illumina). An average of 63 million clean reads per library was obtained, and approximately 80% of these genes were successfully mapped to the reference genome. A total of 1591 up-regulated and 530 down-regulated genes were identified. Eight immune-related categories involving 105 differently expressed genes were scrutinized. 16 of the differently expressed genes involving immune response were further validated by qRT-PCR. Our results provide valuable information for further analysis of the mechanisms of grass carp defense against A. hydrophila invasion. PMID:26945937

  8. 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

    2016-03-01

    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. PMID:26927173

  9. Enterotoxigenicidade de cepas de Aeromonas sp. isoladas em diferentes pontos do fluxograma de abate bovino

    OpenAIRE

    Rossi Júnior O.D.; Amaral L.A.; Nader Filho A; Schocken-Iturrino R.P.

    2001-01-01

    Com o objetivo de verificar a capacidade enterotoxigênica de cepas de Aeromonas sp. isoladas em diferentes produtos e locais no fluxograma de abate bovino, foram testadas 102 cepas (18 da espécie A. hydrophila, 65 da espécie A. caviae e 19 atípicas) ante os testes de inoculação intragástrica em camundongo lactente e em alça intestinal ligada de coelho. Revelaram-se como produtoras de enterotoxinas três (16,7%) cepas da espécie A. hydrophila, originárias das mãos do manipulador antes que ele i...

  10. A novel method for the diagnosis of drowning by detection of Aeromonas sobria with PCR method.

    Science.gov (United States)

    Aoyagi, Miwako; Iwadate, Kimiharu; Fukui, Kenji; Abe, Shuntaro; Sakai, Kentaro; Maebashi, Kyoko; Ochiai, Eriko; Nakamura, Mihoko

    2009-11-01

    The acid digestion method has been widely used for the diagnosis of death by drowning, but it is not always sensitive. However, there has been no definitive method to replace acid digestion until now. We speculate that bacteria are more useful markers than plankton for the diagnosis of death by drowning. In this study, from the preserved blood samples of 32 freshwater drowning cases, specific DNA fragments of Aeromonas sobria, one of the most common aquatic bacteria, were examined using PCR. The DNA fragments of the bacterium were detected from 27 of 32 cases with first round PCR or nested-PCR. The remaining 5 cases in which bacterial DNA was not detected had longer storage periods for the blood samples and shorter time intervals from drowning to death. These results indicate that the present method can be applied to the diagnosis of death by drowning. PMID:19766051

  11. Crystallization and initial X-ray analysis of polyhydroxyalkanoate granule-associated protein from Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Minglian; Li, Zhenguo; Zheng, Wei; Lou, Zhiyong [MOE Key Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 (China); Chen, Guo-Qiang, E-mail: chengq@stu.edu.cn [MOE Key Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 (China); Multidisciplinary Research Center, Shantou University, Shantou 515063, Guangdong (China)

    2006-08-01

    The phasin PhaP{sub Ah} from A. hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Polyhydroxyalkanoate (PHA) granule-associated proteins (phasins) were discovered in PHA-accumulating bacteria. They play a crucial role as a structural protein during initial PHA-granule formation and granule growth and also serve as interfaces for granule stabilization in vivo. The phasin PhaP{sub Ah} from Aeromonas hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Single crystals were cryocooled for X-ray diffraction analysis. The phasin crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 80.8, b = 108.9, c = 134.4 Å.

  12. Survival of Fish-Pathogenic Strains of Aeromonas hydrophila under Starvation.

    Science.gov (United States)

    Zhang, Xiaojun; Cai, Wenlong; Tao, Zhen; Arias, Cova R

    2014-09-01

    Abstract The survival of Aeromonas hydrophila under low-nutrient conditions was investigated in this study. The behavior of three strains isolated from Common Carp Cyprinus carpio (China) and Channel Catfish Ictalurus punctatus (USA) was compared when cells were starved at different temperatures (4, 15, 25, and 35°C) over a 4-week period. Temperature played a major role in cell survival, and cell viability decreased rapidly at 4°C. Conversely, cells stored at 15°C did not lose viability over time. Warmer temperatures (25°C and 35°C) decreased cell numbers by approximately one order of magnitude. Ultrastructural changes in cell morphology were observed in starved cells. Our data confirm that A. hydrophila can persist in the aquatic environment for extended periods, but survival is strongly influenced by temperature. Received December 13, 2013; accepted March 22, 2014. PMID:25229491

  13. Effect of starvation on survival and virulence expression of Aeromonas hydrophila from different sources.

    Science.gov (United States)

    Casabianca, Anna; Orlandi, Chiara; Barbieri, Federica; Sabatini, Luigia; Di Cesare, Andrea; Sisti, Davide; Pasquaroli, Sonia; Magnani, Mauro; Citterio, Barbara

    2015-04-01

    Aeromonas hydrophila is an aquatic bacterium responsible for several human illnesses. The aim of this work was to investigate the survival ability and virulence expression of two strains from different sources (fish, strain 87 and surface water, strain LS) maintained in a seawater microcosm. The strains were analyzed for the total and viable bacterial counts, adhesion ability to Hep-2 cells and aerA gene expression by qPCR throughout the experiment (35 days). Both strains reached a putative VBNC state and lost adhesive properties but exhibited a different behavior in the expression of aerA. This could be due to the different origin of the two strains; the former adapted to a habitat rich of nutrient and the latter already used to survive in a more hostile environment. Moreover, our results indicate that the quantitative determination of aerA mRNA can be a useful indicator of virulence expression under stress conditions. PMID:25533849

  14. Culture-independent methodologies to assess diversity and dynamics of Aeromonas communities

    OpenAIRE

    Calhau, Vera Mónica Tavares Vinhas

    2008-01-01

    As Aeromonas são bactérias autóctones em ambientes aquáticos e constituem um grave problema em sistemas de aquacultura devido à sua capacidade de provocar doença em peixes. Estas bactérias são actualmente consideradas patogéneos emergentes em humanos. Os surtos de doença podem estar associados à introdução de estirpes virulentas que evoluíram a partir de outros nichos ou da aquisição de determinantes de virulência do mesmo nicho, ou ainda como resultado de um desequilíbrio n...

  15. Complexity of β-lactamases among clinical Aeromonas isolates and its clinical implications.

    Science.gov (United States)

    Chen, Po-Lin; Ko, Wen-Chien; Wu, Chi-Jung

    2012-12-01

    Aeromonas species, aquatic Gram-negative bacilli, distributed globally and ubiquitously in the natural environment, may be implicated in a variety of human diseases. They can produce various β-lactamases which confer resistance to a broad spectrum of β-lactams, and therefore in vitro susceptibility testing must be used to guide antimicrobial therapy. However, conventional in vitro susceptibility tests may sometimes fail to detect these β-lactamases, and hence raise a therapeutic challenge. In this review article, two chromosomally mediated β-lactamases (i.e., AmpC β-lactamases and metallo-β-lactamases) and acquired extended-spectrum β-lactamases in aeromonads are reviewed, and the clinical implications of the complexity of β-lactamases are discussed. PMID:23031536

  16. 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.

  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

    2016-01-01

    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. PMID:26927173

  19. Combined effect of gamma-irradiation and conventional cooking on Aeromonas hydrophila in meatball

    International Nuclear Information System (INIS)

    Irradiation combined with a conventional cooking procedure was applied to meatball and the effects on bacterial load and inoculated Aeromonas hydrophila were determined. Meatball samples were irradiated by using a 60Co source at the dose levels of 0, 0.30, 0.75, 1.50, 2.50 kGy and cold stored at 4 +/- 1 degrees C for 7 days. Bacterial load and the count of A. hydrophila decreased when the irradiation dose level increased. A minimum inhibition effect was found at the dose of 0.30 kGy. Irradiation in combination with a conventional cooking procedure was found to be more effective in reducing A. hydrophila and the bacterial load in meatball. This study indicated that a dose of 0.75 kGy was sufficient to destroy approximately 10(4) cfu/g of A. hydrophila in meatball

  20. Isolation of bacterial fish pathogen Aeromonas hydrophila and therapeutic effects of medicinal plants on its invasion

    Directory of Open Access Journals (Sweden)

    Md. Tareq-Uz-Zaman

    2014-04-01

    Full Text Available Aeromonas hydrophila, a bacterial pathogen, was isolated form Pangasius hypophthalmus. For pathogenicity test, different doses were injected intramuscularly in Barbonymus gonionotus. Crude extracts were prepared from various parts Azadirachta indica, Curcuma longa, C. zedoaria, and Callotropis gigentia and applied to B. gonionotus for 7 days. Bath treatment was done up to their tolerance level and well ventilation was confirmed for aeration and 50% water was exchanged daily. Minimum inhibitory dose was detected as 7 mg/ml. High inhibitory effect was observed in case of A. indica and mixed extract of A. indica and C. gigentia. Both A. indica and C. gigentia showed the best result with 90-95% recovery of infected fish at a dose of 7 mg/l. C. zedoaria showed moderate to weak effect with 50-60% recovery at the same dose. The present study showed that medicinal plants would be an effective control measure against A. hydrophila.

  1. Intragenic variation by site-specific recombination in the cryptic plasmid of Neisseria gonorrhoeae.

    OpenAIRE

    Hagblom, P; Korch, C; Jonsson, A B; Normark, S

    1986-01-01

    Cryptic plasmid DNA of Neisseria gonorrhoeae was found integrated into the gonococcal chromosome in both plasmid-bearing strains and plasmid-free strains. At several chromosomal locations only segments of the plasmid were found. However, in at least two strains an intact copy of the plasmid seemed to be present with the joints between the plasmid and the chromosomal DNA being located within the cppB gene of the cryptic plasmid. The cppB gene was shown to undergo a sequence-specific intragenic...

  2. Plasmid vector with temperature-controlled gene expression

    International Nuclear Information System (INIS)

    In plasmid pBR327, a fragment 169 b.p. long including promotor p3 of the bla gene has been deleted. The deletional derivative so obtained (pSP2) has been used to construct a recombinant plasmid bearing a fragment of phage λ DNA with the p/sub R/ promotor and the gene of the temperature-sensitive repressor cI. It has been shown that the plasmid vector so constructed (pCE119) with promotor cR performs repressor-cI-controlled transcription of the bla gene, as a result of which induction for an hour at 420C leads to an almost 100-fold increase in the amount of product of the bla gene as compared with that at 320C. The possibility of the use of plasmid cPE119 for the expression of other genes has been demonstrated for the case of the semisynthetic β-galactosidase gene of E. coli. In this case, on induction of the cells with recombinant plasmid pCEZ12 for 3 hours at 420C, a 300-fold increase in the amount of active β-galactosidase, as compared with that at 320C, was observed. It is important to point out that under these conditions (at 420C), at least 99% of the cells containing the plasmid retain the phenotype lacZ+, which indicates the stability of the proposed vector system

  3. Transfer of conjugative plasmids among bacteria under environmentally relevant conditions

    DEFF Research Database (Denmark)

    Musovic, Sanin

    det oprindelige bakteriesamfund der tager andel i plasmid overførsel blev udviklet. Dyrknings-minimal metode i kombination med reporter gen teknologi og moderne mikroskopi viste en meget høj forekomst af RP4:gfp plasmid overførsel til oprindelige jord bakterier af et bredt værtskab. Der blev også vist......Mobile genetiske elementer (f.eks. plasmider), der ofte bærer ekstra funktioner såsom antibiotikaresistens, eller kataboliske- og xenobiotiske nedbrydnings gener, antages at have en meget vigtigt evolutionær rolle for bakterier. I denne PhD afhandling undersøgte jeg størrelsen af plasmid overførsel...... under de miljørelevante substrat-begrænsede forhold, den del og diversitet af bakteriel samfund der er involveret i overførslen, og effekten af plasmid donor cellens fysiologiske status og de miljørelevante faktorer (selektive tryk) på plasmid spredning. En ny metode til at kvantificere den fraktion af...

  4. The characteristics of micrococcus (deinococcus) radiodurans sark plasmids

    International Nuclear Information System (INIS)

    The characterization of micrococcus (deinococcus) radiodurans sark plasmids. This bacterium has been classified as a new genus deinococcus radiodurans which is resistant to gamma-rays. It can repair itself completely almost all of DNA damages including double strand breaks induced by gamma-rays up to about 5 KGy. To reveal the repair mechanism, several investigations had been done to develop a cloning vector available for the genetic analysis. For this purpose D. radiodurans Sark are to be prepared as a vector by studying the characteristics of its plasmid. Plasmids were isolated by electrophoresis using 0.6% low-melting-temperature agarose in TAE and run for 5.5 hours, followed by the identification. An antibiotic marker was also carried out in this experiment to identify its location in the genetic materials of the cell, beside making a restriction map of the plasmid. Results have shown that D. radiodurans Sark has 4 plasmids (P1, P2, P3, and P4) and the refampicin resistant genes were not found in the plasmid. (authors). 14 refs; 4 figs

  5. Plasmid-free T7-based Escherichia coli expression systems.

    Science.gov (United States)

    Striedner, Gerald; Pfaffenzeller, Irene; Markus, Luchner; Nemecek, Sabine; Grabherr, Reingard; Bayer, Karl

    2010-03-01

    In order to release host cells from plasmid-mediated increases in metabolic load and high gene dosages, we developed a plasmid-free, T7-based E. coli expression system in which the target gene is site-specifically integrated into the genome of the host. With this system, plasmid-loss, a source of instability for conventional expression systems, was eliminated. At the same time, system leakiness, a challenging problem with recombinant systems, was minimized. The efficiency of the T7 RNA polymerase compensates for low gene dosage and provides high rates of recombinant gene expression without fatal consequences to host metabolism. Relative to conventional pET systems, this system permits improved process stability and increases the host cell's capacity for recombinant gene expression, resulting in higher product yields. The stability of the plasmid-free system was proven in chemostat cultivation for 40 generations in a non-induced and for 10 generations in a fully induced state. For this reason plasmid-free systems benefit the development of continuous production processes with E. coli. However, time and effort of the more complex cloning procedure have to be considered in relation to the advantages of plasmid-free systems in upstream-processing. PMID:19891007

  6. Partition-associated incompatibility caused by random assortment of pure plasmid clusters

    DEFF Research Database (Denmark)

    Ebersbach, Gitte; Sherratt, David J; Gerdes, Kenn;

    2005-01-01

    Summary Bacterial plasmids and chromosomes encode centromere-like partition loci that actively segregate DNA before cell division. The molecular mechanism behind DNA segregation in bacteria is largely unknown. Here we analyse the mechanism of partition-associated incompatibility for plasmid pB171......, a phenotype associated with all known plasmid-encoded centromere loci. An R1 plasmid carrying par2 from plasmid pB171 was destabilized by the presence of an F plasmid carrying parC1, parC2 or the entire par2 locus of pB171. Strikingly, cytological double-labelling experiments revealed no evidence of long......-lived pairing of plasmids. Instead, pure R1 and F foci were positioned along the length of the cell, and in a random order. Thus, our results raise the possibility that partition-mediated plasmid incompatibility is not caused by pairing of heterologous plasmids but instead by random positioning of pure plasmid...

  7. Biofilm formation by Aeromonas hydrophila on green-leafy vegetables: cabbage and lettuce.

    Science.gov (United States)

    Elhariry, Hesham M

    2011-01-01

    Aeromonas hydrophila is the most well known of the six species of Aeromonas, which has been linked to two groups of human diseases: septicemia and gastroenteritis. Reference strain ATCC 7966 and biofilm strains TUB19, TUB20, and TUB21 were investigated for their ability to form biofilm in vitro (after 48 h on polystyrene surface) and on the surface of two green-leafy vegetables, cabbage and lettuce (after 1, 2, 4, and 24 h). Attachment strength (S(R)) of these strains to the vegetable surface was also measured in the same time intervals. The ATCC 7966 and TUB19 had high ability to form biofilm in vitro compared with TUB20 and TUB21 in full strength tryptone soy broth or under starvation conditions in diluted tryptone soy broth (1:20, v/v). Cell surface hydrophobicity of the biofilm strains was lower than that of the reference strain. The biofilm of all tested strains on polystyrene surfaces differed from that on the vegetable surfaces. All strains studied rapidly attached to both green leafy vegetables (after 1 h). S(R) and cell populations (loosely and strongly attached cells) significantly (p 0.05) differences in cell populations were recorded after 4 and 24 h. The highest S(R) and cell population (log CFU cm⁻²) were recorded by TUB19. In conclusion, the use of A. hydrophila strains isolated from environmental biofilm samples may be more useful for understanding biofilm formation on green-leafy vegetables than the reference or laboratory strains. The attachment of A. hydrophila was significantly affected by the surfaces of green-leafy vegetables. Further studies are required to improve our understanding of the interaction between human microbial pathogens and surfaces of raw vegetables. PMID:21034267

  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. 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. PMID:23397109

  10. Genetic markers for detection of Escherichia coli K-12 harboring ampicillin-resistance plasmid from an industrial wastewater treatment effluent pond.

    Science.gov (United States)

    Simões, G A R; Xavier, M A S; Oliveira, D A; Menezes, E V; Magalhães, S S G; Gandra, J A C D; Xavier, A R E O

    2016-01-01

    Biotechnology industries that use recombinant DNA technology are potential sources for release of genetically modified organisms to the environment. Antibiotic-resistance marker genes are commonly used for recombinant bacteria selection. One example is the marker gene coding for β-lactamase (bla) in plasmids found in Escherichia coli K-12. The aim of this study was to provide an approach to develop a molecular method for genetic marker detection in E. coli K-12 harboring bla genes from an industrial wastewater treatment effluent pond (IWTEP). For the detection of bla and Achromobacter lyticus protease I (api) genes in samples from IWTEP, we employed multiplex polymerase chain reaction (PCR) using E. coli K-12 genetic marker detection primers, previously described in the literature, and primers designed in our laboratory. The microbiological screening method resulted in 22 bacterial colony-forming units isolated from three different IWTEP harvesting points. The multiplex PCR amplicons showed that five isolates were positive for the bla gene marker and negative for the E. coli K-12 and api genes. The 16S rRNA regions of positive microorganisms carrying the bla gene were genotyped by the MicroSeq®500 system. The bacteria found were Escherichia spp (3/5), Chromobacterium spp (1/5), and Aeromonas spp (1/5). None of the 22 isolated microorganisms presented the molecular pattern of E. coli K-12 harboring the bla gene. The presence of microorganisms positive for the bla gene and negative for E. coli K-12 harboring bla genes at IWTEP suggests that the ampicillin resistance found in the isolated bacteria could be from microorganisms other than the E. coli K-12 strain harboring plasmid. PMID:27323199

  11. 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

  12. Tyrosine Partners Coordinate DNA Nicking by the Salmonella typhimurium Plasmid pCU1 Relaxase Enzyme

    OpenAIRE

    Nash, Rebekah P.; Niblock, Franklin C.; Redinbo, Matthew R.

    2011-01-01

    Conjugative plasmid transfer results in the spread of antibiotic resistance genes and virulence factors between bacterial cells. Plasmid transfer is dependent upon the DNA nicking activity of a plasmid-encoded relaxase enzyme. Tyrosine residues within the relaxase cleave the DNA plasmid nic site in a highly sequence-specific manner. The conjugative resistance plasmid pCU1 encodes a relaxase with four tyrosine residues surrounding its active site (Y18,19,26,27). We use activity assays to demon...

  13. Linear Plasmid SLP2 Is Maintained by Partitioning, Intrahyphal Spread, and Conjugal Transfer in Streptomyces▿

    OpenAIRE

    Hsu, Chin-Chen; Chen, Carton W.

    2009-01-01

    Low-copy-number plasmids generally encode a partitioning system to ensure proper segregation after replication. Little is known about partitioning of linear plasmids in Streptomyces. SLP2 is a 50-kb low-copy-number linear plasmid in Streptomyces lividans, which contains a typical parAB partitioning operon. In S. lividans and Streptomyces coelicolor, a parAB deletion resulted in moderate plasmid loss and growth retardation of colonies. The latter was caused by conjugal transfer from plasmid-co...

  14. Transfer of chimeric plasmids among Salmonella typhimurium strains by P22 transduction.

    OpenAIRE

    Orbach, M J; Jackson, E N

    1982-01-01

    Salmonella typhimurium bacteriophage P22 transduced plasmids having P22 sequences inserted in the vector pBR322 with high frequency. Analysis of the structure of the transducing particle DNA and the transduced plasmids indicates that this plasmid transduction involves two homologous recombination events. In the donor cell, a single recombination between the phage and the homologous sequences on the plasmid inserted the plasmid into the phage chromosome, which was then packaged by headfuls int...

  15. Exposing Plasmids as the Achilles’ Heel of Drug-Resistant Bacteria

    OpenAIRE

    Williams, Julia J.; Hergenrother, Paul J.

    2008-01-01

    Many multi-drug resistant bacterial pathogens harbor large plasmids that encode proteins conferring resistance to antibiotics. While the acquisition of these plasmids often enables bacteria to survive in the presence of antibiotics, it is possible that plasmids also represent a vulnerability that can be exploited in tailored antibacterial therapy. This review highlights three recently described strategies designed to specifically combat bacteria harboring such plasmids: Inhibition of plasmid ...

  16. Sequence-nonspecific replication of transfected plasmid DNA in poxvirus-infected cells.

    OpenAIRE

    DeLange, A. M.; McFadden, G

    1986-01-01

    A system in which transfected plasmid DNA replicates in the cytoplasm of poxvirus-infected cells is described. A variety of recombinant plasmids was introduced into poxvirus-infected cells by transfection, and replication of input plasmid DNA was monitored by (i) digestion with restriction enzymes that discriminate between input methylated plasmid DNA and unmethylated DNA produced by replication in mammalian cells; (ii) amplification of intracellular plasmid DNA; and (iii) density shift analy...

  17. Characterization of plasmid burden and copy number in Saccharomyces cerevisiae for optimization of metabolic engineering applications

    OpenAIRE

    Karim, Ashty S.; Curran, Kathleen A.; Alper, Hal S.

    2012-01-01

    Many metabolic engineering and genetic engineering applications in yeast rely on the use of plasmids. Despite their pervasive use and the diverse collections available, there is a fundamental lack of understanding of how commonly used DNA plasmids affect the cell’s ability to grow and how the choice of plasmid components can influence plasmid load and burden. In this study, we characterized the major attributes of the 2μ and centromeric plasmids typically used in yeast by examining the impact...

  18. Hofmeister series salts enhance purification of plasmid DNA by non-ionic detergents

    OpenAIRE

    Lezin, George; Kuehn, Michael R.; Brunelli, Luca

    2011-01-01

    Ion-exchange chromatography is the standard technique used for plasmid DNA purification, an essential molecular biology procedure. Non-ionic detergents (NIDs) have been used for plasmid DNA purification, but it is unclear whether Hofmeister series salts (HSS) change the solubility and phase separation properties of specific NIDs, enhancing plasmid DNA purification. After scaling-up NID-mediated plasmid DNA isolation, we established that NIDs in HSS solutions minimize plasmid DNA contamination...

  19. Comparison of Ti plasmids from three different biotypes of Agrobacterium tumefaciens isolated from grapevines.

    OpenAIRE

    Knauf, V C; Panagopoulos, C G; Nester, E. W.

    1983-01-01

    Twenty-six plasmids from grapevine isolates of Agrobacterium tumefaciens were analyzed by SmaI fingerprinting and by hybridization of nick-translated DNA to DNA of another plasmid. These experiments established that octopine Ti plasmids are not highly conserved, although octopine Ti plasmids from biotype 1 A. tumefaciens strains appeared to be very similar. Octopine Ti plasmids from biotype 3 strains are more variable in terms of host range and SmaI fingerprints, but share extensive DNA homol...

  20. Antibiotic resistence of Aeromonas hydrophila isolated from Piaractus mesopotamicus (Holmberg, 1887) and Oreochromis niloticus (Linnaeus, 1758) Resistência de Aeromonas hydrophila isolada de Piaractus mesopotamicus (Holmberg, 1887) e Oreochromis niloticus (Linnaeus, 1758) a antibióticos

    OpenAIRE

    Andréa Belém-Costa; José Eurico Possebon Cyrino

    2006-01-01

    One of the most important problems involving treatments with antibiotics against Aeromonas hydrophila isolated from fishes is that antibiotic resistance develops readily. The antimicrobial activity of chemotherapeutants in isolates from pacu Piaractus mesopotamicus (Holmberg, 1887) and tilapia Oreochromis niloticus (Linnaeus, 1758) was tested by the Kirby-Bauer disk method, over Mueller-Hinton surface agar previously inoculated with 100 µL of bacterial suspensions. After regular incubation, i...