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Sample records for aeromonas hydrophila aeromonas

  1. Aeromonas hydrophila surveillance 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Virulent Aeromonas hydrophila in channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Aeromonas hydrophila produces conductive nanowires.

    PubMed

    Castro, Laura; Vera, Mario; Muñoz, Jesús Ángel; Blázquez, María Luisa; González, Felisa; Sand, Wolfgang; Ballester, Antonio

    2014-11-01

    Aeromonas hydrophila is a facultative anaerobe which, under conditions of oxygen depletion, uses Fe(III) as electron acceptor. A. hydrophila produces pili during growth with Fe(III). The study was focused on the characterization of the morphology, the electrical properties and the nature of the bacterial pili. Scanning electron microscopy and conductive-probe atomic force microscopy revealed the presence of filaments between cells and substrate and their conductive nature. Our results indicate that pili of A. hydrophila strain A might serve as biological nanowires, transferring electrons from the cell surface to the surface of Fe(III) oxides and, in addition, the possibility of playing a role in inter/intra species signaling. Quorum sensing (QS) is recognized as one of the main regulatory ways for extracellular polymeric substances (EPS) production and biofilm formation. We present evidence that nanowire formation can be regulated by addition of synthetic acyl-homoserine lactones (AHL). These conductive pili may be involved in various interactions, and their protein components might be usable in the future for biotechnological approaches in materials science. PMID:25283724

  4. Complete genome sequence of Aeromonas hydrophila AL06-06

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Enumeration and characterization of Aeromonas hydrophila and Aeromonas caviae isolated from grocery store produce.

    PubMed

    Callister, S M; Agger, W A

    1987-02-01

    Starch-ampicillin agar was used to quantitatively isolate Aeromonas sp. from retail grocery store produce. All produce sampled, including parsley, spinach, celery, alfalfa sprouts, broccoli, and lettuce, contained Aeromonas sp. In most instances, the count of Aeromonas sp. increased 10- to 1,000-fold during 2 weeks of storage at 5 degrees C. Eleven (92%) of 12 kinds of produce yielded cytotoxic Aeromonas sp. Identification as Aeromonas hydrophila was the strongest indicator of cytotoxicity, and all 29 (100%) A. hydrophila isolates and 1 (6%) of 16 A. caviae isolates were cytotoxic. Twenty-seven (90%) of 30 cytotoxic Aeromonas sp. strains produced hemolysins. Strong correlations were also noted between ability to produce cytotoxin and positive Voges-Proskauer, lysine decarboxylase, and sorbitol fermentation reactions. It appears that grocery store produce is a potentially significant source of cytotoxic Aeromonas sp. and should be considered in the epidemiology of A. hydrophila gastroenteritis. PMID:3566266

  6. Complete Genome Sequence of Fish Pathogen Aeromonas hydrophila JBN2301.

    PubMed

    Yang, Wuming; Li, Ningqiu; Li, Ming; Zhang, Defeng; An, Guannan

    2016-01-01

    Aeromonas hydrophila is one of the most important fish pathogens in China. Here, we report complete genome sequence of a virulent strain, A. hydrophila JBN2301, which was isolated from diseased crucian carp. PMID:26823580

  7. Complete Genome Sequence of Fish Pathogen Aeromonas hydrophila JBN2301

    PubMed Central

    Yang, Wuming; Li, Ming; Zhang, Defeng; An, Guannan

    2016-01-01

    Aeromonas hydrophila is one of the most important fish pathogens in China. Here, we report complete genome sequence of a virulent strain, A. hydrophila JBN2301, which was isolated from diseased crucian carp. PMID:26823580

  8. Draft genome sequence of Aeromonas hydrophila TN97-08

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Aeromonas hydrophila Lateral Flagellar Gene Transcriptional Hierarchy

    PubMed Central

    Wilhelms, Markus; Gonzalez, Victor; Merino, Susana

    2013-01-01

    Aeromonas hydrophila AH-3 lateral flagella are not assembled when bacteria grow in liquid media; however, lateral flagellar genes are transcribed. Our results indicate that A. hydrophila lateral flagellar genes are transcribed at three levels (class I to III genes) and share some similarities with, but have many important differences from, genes of Vibrio parahaemolyticus. A. hydrophila lateral flagellum class I gene transcription is σ70 dependent, which is consistent with the fact that lateral flagellum is constitutively transcribed, in contrast to the characteristics of V. parahaemolyticus. The fact that multiple genes are included in class I highlights that lateral flagellar genes are less hierarchically transcribed than polar flagellum genes. The A. hydrophila lafK-fliEJL gene cluster (where the subscript L distinguishes genes for lateral flagella from those for polar flagella) is exclusively from class I and is in V. parahaemolyticus class I and II. Furthermore, the A. hydrophila flgAMNL cluster is not transcribed from the σ54/LafK-dependent promoter and does not contain class II genes. Here, we propose a gene transcriptional hierarchy for the A. hydrophila lateral flagella. PMID:23335410

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    PubMed

    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

  13. Quorum sensing regulation in Aeromonas hydrophila.

    PubMed

    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

  14. Aeromonas hydrophila and Aeromonas veronii Predominate among Potentially Pathogenic Ciprofloxacin- and Tetracycline-Resistant Aeromonas Isolates from Lake Erie

    PubMed Central

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

    2014-01-01

    Members of the genus Aeromonas are ubiquitous in nature and have increasingly been implicated in numerous diseases of humans and other animal taxa. Although some species of aeromonads are human pathogens, their presence, density, and relative abundance are rarely considered in assessing water quality. The objectives of this study were to identify Aeromonas species within Lake Erie, determine their antibiotic resistance patterns, and assess their potential pathogenicity. Aeromonas strains were isolated from Lake Erie water by use of Aeromonas selective agar with and without tetracycline and ciprofloxacin. All isolates were analyzed for hemolytic ability and cytotoxicity against human epithelial cells and were identified to the species level by using 16S rRNA gene restriction fragment length polymorphisms and phylogenetic analysis based on gyrB gene sequences. A molecular virulence profile was identified for each isolate, using multiplex PCR analysis of six virulence genes. We demonstrated that Aeromonas comprised 16% of all culturable bacteria from Lake Erie. Among 119 Aeromonas isolates, six species were identified, though only two species (Aeromonas hydrophila and A. veronii) predominated among tetracycline- and ciprofloxacin-resistant isolates. Additionally, both of these species demonstrated pathogenic phenotypes in vitro. Virulence gene profiles demonstrated a high prevalence of aerolysin and serine protease genes among A. hydrophila and A. veronii isolates, a genetic profile which corresponded with pathogenic phenotypes. Together, our findings demonstrate increased antibiotic resistance among potentially pathogenic strains of aeromonads, illustrating an emerging potential health concern. PMID:24242249

  15. Draft Genome Sequence of Aeromonas hydrophila TN97-08

    PubMed Central

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

    2016-01-01

    Aeromonas hydrophila is an opportunistic pathogen residing in freshwater environments that causes infection in fish and mammals. Here, we report the draft genome sequence of A. hydrophila strain TN97-08 isolated from a diseased bluegill (Lepomis macrochirus) in 1997. PMID:27231367

  16. Aeromonas hydrophila in 2010: Characteristics of Alabama outbreaks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. Draft Genome Sequence of Aeromonas hydrophila TN97-08.

    PubMed

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

    2016-01-01

    Aeromonas hydrophila is an opportunistic pathogen residing in freshwater environments that causes infection in fish and mammals. Here, we report the draft genome sequence of A. hydrophila strain TN97-08 isolated from a diseased bluegill (Lepomis macrochirus) in 1997. PMID:27231367

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    PubMed

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  1. Aeromonas hydrophila Sepsis Associated with Consumption of Raw Oysters

    PubMed Central

    Goldman, John; Cheriyath, Pramil; Nookala, Vinod

    2014-01-01

    Introduction. Aeromonas hydrophila is a gram negative bacillus that is native to aquatic environments that is increasingly reported in humans. This case is remarkable for A. hydrophila with an initial presentation of acute pancreatitis. Case Presentation. A 61-year-old male presented to the emergency department with nausea, vomiting, and abdominal pain for two days. His past medical history was significant for alcohol abuse. Initial laboratory examination showed an elevated white blood cell count, elevated lipase, and elevated liver function tests (LFT). Computer tomography (CT) showed peripancreatic inflammatory changes and retroperitoneal free fluid, suggestive of acute pancreatitis. The patient was treated with intravenous (IV) fluids and IV meropenem. After two days, the patient developed sepsis and respiratory failure and was intubated. Blood cultures were positive for Aeromonas hydrophila sensitive to ciprofloxacin which was added to his treatment. Additionally, it was discovered that this patient had recently vacationed in Florida where he consumed raw oysters. He was discharged home on the eighth day of the hospital admission. Conclusion. This is a rare case of A. hydrophila sepsis in an elderly patient with acute pancreatitis and a history of consumption of raw oysters. This case suggests that A. hydrophila can cause disseminated infection in immunocompetent individuals. PMID:25506003

  2. Aeromonas hydrophila Sepsis Associated with Consumption of Raw Oysters.

    PubMed

    Nikiforov, Ivan; Goldman, John; Cheriyath, Pramil; Vyas, Anix; Nookala, Vinod

    2014-01-01

    Introduction. Aeromonas hydrophila is a gram negative bacillus that is native to aquatic environments that is increasingly reported in humans. This case is remarkable for A. hydrophila with an initial presentation of acute pancreatitis. Case Presentation. A 61-year-old male presented to the emergency department with nausea, vomiting, and abdominal pain for two days. His past medical history was significant for alcohol abuse. Initial laboratory examination showed an elevated white blood cell count, elevated lipase, and elevated liver function tests (LFT). Computer tomography (CT) showed peripancreatic inflammatory changes and retroperitoneal free fluid, suggestive of acute pancreatitis. The patient was treated with intravenous (IV) fluids and IV meropenem. After two days, the patient developed sepsis and respiratory failure and was intubated. Blood cultures were positive for Aeromonas hydrophila sensitive to ciprofloxacin which was added to his treatment. Additionally, it was discovered that this patient had recently vacationed in Florida where he consumed raw oysters. He was discharged home on the eighth day of the hospital admission. Conclusion. This is a rare case of A. hydrophila sepsis in an elderly patient with acute pancreatitis and a history of consumption of raw oysters. This case suggests that A. hydrophila can cause disseminated infection in immunocompetent individuals. PMID:25506003

  3. Chemotaxis of Aeromonas hydrophila to the surface mucus of fish

    SciTech Connect

    Hazen, T.C.; Esch, G.W.; Dimock, R.V. Jr.; Mansfield, A.

    1982-01-01

    Isolates of Aeromonas hydrophila from various sources show different chemotactic responses to mucus from the surface of freshwater fish. Some isolates were nonchemotactic to fish surface mucus. Isolates of A. hydrophila from fish lesions had a significantly higher chemotactic index than isolates of A. hydrophila from water. Maximum chemotactic responses occurred more often to diluted fish mucus than to undiluted samples. Fish which were experimentally stressed did not produce mucus that was more or less chemotactic than that of unstressed fish. Fish with red-sore lesions produced surface mucus which was not chemotactic to A. hydrophila. Differences between fish, for any isolate, were also not significant. The chemotactic substance(s) in fish mucus has a molecular weight of approximately 100,000 and did not appear to be labile when heated to 56/sup 0/C.

  4. Contribution of nuclease to the pathogenesis of Aeromonas hydrophila

    PubMed Central

    Ji, Yachan; Li, Jinquan; Qin, Zhendong; Li, Aihua; Gu, Zemao; Liu, Xiaoling; Lin, Li; Zhou, Yang

    2015-01-01

    Aeromonas hydrophila is a gram-negative bacterium that is widely distributed in aquatic environments and can cause septicemia in both fish and humans. However, the underlying mechanisms leading to severe infection are not well understood. In this study, an A. hydrophila nuclease (ahn) deletion mutant was constructed to investigate its contribution to pathogenesis. This mutant did not differ from the wild-type strain in terms of its growth or hemolytic phenotype. However, the ahn-deficient mutant was more susceptible to being killed by fish macrophages and mouse blood in vitro. Furthermore, evidence obtained using both fish and murine infection models strongly indicated that the inactivation of Ahn impaired the ability of A. hydrophila to evade innate immune clearance in vivo. More importantly, the virulence of the mutant was attenuated in both fish and mice, with reductions in dissemination capacities and mortality rates. These findings implicate Ahn in A. hydrophila virulence, with important functions in evading innate immune defenses. PMID:26039879

  5. Transcriptional Hierarchy of Aeromonas hydrophila Polar-Flagellum Genes▿

    PubMed Central

    Wilhelms, Markus; Molero, Raquel; Shaw, Jonathan G.; Tomás, Juan M.; Merino, Susana

    2011-01-01

    Aeromonas hydrophila polar-flagellum class I gene transcription is σ70 dependent, which is consistent with the fact that the A. hydrophila polar flagellum is constitutively expressed. In contrast to other bacteria with dual flagellar systems such as Vibrio parahaemolyticus, the A. hydrophila LafK protein does not compensate for the lack of the polar-flagellum regulator FlrA (V. parahaemolyticus FlaK homologue). This is consistent with the fact that the A. hydrophila FlrA mutation abolishes polar-flagellum formation in liquid and on solid surfaces but does not affect inducible lateral-flagellum formation. The results highlight that the polar- and lateral-flagellum interconnections and control networks are specific and that there are differences between the dual flagellar systems in A. hydrophila and V. parahaemolyticus. Furthermore, our results indicate that the A. hydrophila polar-flagellum transcriptional hierarchy (also in class II, III, and IV genes) shares some similarities with but has many important differences from the transcriptional hierarchies of Vibrio cholerae and Pseudomonas aeruginosa. The A. hydrophila flhF and flhG genes are essential for the assembly of a functional polar flagellum because in-frame mutants fail to swim in liquid medium and lack the polar flagellum. In Vibrio and Pseudomonas flhG disruption increases the number of polar flagella per cell, and Pseudomonas flhF disruption gives an aberrant placement of flagellum. Here, we propose the gene transcriptional hierarchy for the A. hydrophila polar flagellum. PMID:21784933

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

    PubMed

    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

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

    PubMed

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

    PubMed Central

    Forn-Cuní, Gabriel; Tomás, Juan M.

    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

  10. Agglutinating antibody to Aeromonas hydrophila in wild largemouth bass

    SciTech Connect

    Hazen, T.C.; Esch, G.W.; Raker, M.L.

    1981-07-01

    Among largemouth bass Micropterus salmoides in Par Pond, South Carolina, a significantly large percentage of those with red-sore disease were positive for anti-Aeromonas hydrophila agglutinin than of uninfected fish. Highest titers occurred during summer and fall, when the prevalence of the disease was declining. Most agglutinin activity was associated with a single serum fraction; the agglutinin has an apparent molecular weight of > 340,000 daltons, suggesting it may be a macroglobulin-like antibody. Homologous agglutinin reacted better with A. hydrophila than heterologous agglutinin. Differences in severity and duration of red-sore epizootics in the southeastern United States may be due to differing virulence among strains of A. hydrophila.

  11. DNA Adenine Methyltransferase Influences the Virulence of Aeromonas hydrophila

    PubMed Central

    Erova, Tatiana E.; Pillai, Lakshmi; Fadl, Amin A.; Sha, Jian; Wang, Shaofei; Galindo, Cristi L.; Chopra, Ashok K.

    2006-01-01

    Among the various virulence factors produced by Aeromonas hydrophila, a type II secretion system (T2SS)-secreted cytotoxic enterotoxin (Act) and the T3SS are crucial in the pathogenesis of Aeromonas-associated infections. Our laboratory molecularly characterized both Act and the T3SS from a diarrheal isolate, SSU of A. hydrophila, and defined the role of some regulatory genes in modulating the biological effects of Act. In this study, we cloned, sequenced, and expressed the DNA adenine methyltransferase gene of A. hydrophila SSU (damAhSSU) in a T7 promoter-based vector system using Escherichia coli ER2566 as a host strain, which could alter the virulence potential of A. hydrophila. Recombinant Dam, designated as M.AhySSUDam, was produced as a histidine-tagged fusion protein and purified from an E. coli cell lysate using nickel affinity chromatography. The purified Dam had methyltransferase activity, based on its ability to transfer a methyl group from S-adenosyl-l-methionine to N6-methyladenine-free lambda DNA and to protect methylated lambda DNA from digestion with DpnII but not against the DpnI restriction enzyme. The dam gene was essential for the viability of the bacterium, and overproduction of Dam in A. hydrophila SSU, using an arabinose-inducible, PBAD promoter-based system, reduced the virulence of this pathogen. Specifically, overproduction of M.AhySSUDam decreased the motility of the bacterium by 58%. Likewise, the T3SS-associated cytotoxicity, as measured by the release of lactate dehydrogenase enzyme in murine macrophages infected with the Dam-overproducing strain, was diminished by 55% compared to that of a control A. hydrophila SSU strain harboring the pBAD vector alone. On the contrary, cytotoxic and hemolytic activities associated with Act as well as the protease activity in the culture supernatant of a Dam-overproducing strain were increased by 10-, 3-, and 2.4-fold, respectively, compared to those of the control A. hydrophila SSU strain. The Dam

  12. Virulence potential and genetic diversity of Aeromonas caviae, Aeromonas veronii, and Aeromonas hydrophila clinical isolates from Mexico and Spain: a comparative study.

    PubMed

    Aguilera-Arreola, Ma Guadalupe; Hernández-Rodríguez, César; Zúñiga, Gerardo; Figueras, María José; Garduño, Rafael A; Castro-Escarpulli, Graciela

    2007-07-01

    A comparative study of 109 Aeromonas clinical isolates belonging to the 3 species most frequently isolated from patients with diarrhea in Mexico and Spain was performed to investigate the distribution of 3 prominent toxin genes and the gene encoding flagellin of lateral flagella; 4 well-established virulence factors in the genus Aeromonas. The aerolysin-hemolysin toxin genes were the most prevalent, being present in 89% of the total isolates. The ast toxin gene was conspicuously absent from the Aeromonas caviae and Aeromonas veronii groups but was present in 91% of the Aeromonas hydrophila isolates. Both the alt toxin gene and the lafA flagellin gene also had a low incidence in A. caviae and A. veronii. Differences in the prevalence of alt and lafA were observed between isolates from Mexico and Spain, confirming genus heterogeneity according to geographic location. Carriage of multiple toxin genes was primarily restricted to A. hydrophila isolates, suggesting that A. caviae and A. veronii isolates circulating in Mexico and Spain possess a limited array of virulence genes. Enterobacterial repetitive intergenetic consensus - polymerase chain reaction showed that the Aeromonas populations sampled lack dominant clones and were genetically heterogeneous, with A. caviae being the most diverse species. Further surveys of virulence determinants in genetically heterogeneous populations of Aeromonas isolates circulating worldwide are required to enhance the understanding of their capacity to cause disease. PMID:17898843

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

    PubMed Central

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  15. Methods for the isolation of Aeromonas hydrophila and Plesiomonas shigelloides from faeces.

    PubMed Central

    Millership, S. E.; Chattopadhyay, B.

    1984-01-01

    Two solid selective media, xylose deoxycholate citrate agar (XDCA) and bile salts brilliant green agar (BBG) and an enrichment broth-alkaline peptone water, were evaluated for the isolation of Aeromonas hydrophila and Plesiomonas shigelloides. Alkaline peptone water and XDCA are useful for recovery of Aeromonas but not Plesiomonas, whereas BBG is satisfactory for both organisms. PMID:6368683

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. Flagellar motility is necessary for Aeromonas hydrophila adhesion.

    PubMed

    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

  18. Aeromonas hydrophila in livestock: incidence, biochemical characteristics and antibiotic susceptibility.

    PubMed Central

    Gray, S. J.

    1984-01-01

    Faecal samples from 110 horses, 115 pigs, 111 sheep and 123 cows were examined for the presence of Aeromonas hydrophila, which was also sought in the available drinking water. The overall faecal rate was 11.8%, but significantly more bovine than other samples were found to be positive. There was significant association between the isolation of A. hydrophila from all animal faeces and its presence in drinking water, but this was not found when individual animal groups were analysed separately. An enrichment technique increased the total number of isolates by 77.1%. Strains of differing origins could not be differentiated by biotyping, although fermentation of sorbitol was associated with bovine isolates. There was a strong positive correlation between positive reactions for V--P, gluconate oxidase and haemolysis of rabbit erythrocytes, tests which had previously been shown to correlate with production of enterotoxin and cytotoxin. Biotypes giving positive reactions for these tests were most frequently isolated from cows, sheep and untreated water, and less frequently from pigs and horses. Most strains of A. hydrophila were resistant to amoxycillin, carbenicillin and cephradine, and sensitive to gentamicin, chloramphenicol and neomycin. PMID:6736644

  19. Aminoglycoside-Resistant Aeromonas hydrophila as Part of a Polymicrobial Infection following a Traumatic Fall into Freshwater▿

    PubMed Central

    Shak, Joshua R.; Whitaker, Jennifer A.; Ribner, Bruce S.; Burd, Eileen M.

    2011-01-01

    Amikacin is a first-line treatment for Aeromonas infection due to high efficacy. There are few reports of aminoglycoside-resistant Aeromonas spp. We report a soft tissue infection containing multiple pathogens, including a strain of Aeromonas hydrophila resistant to amikacin, tobramycin, and multiple cephalosporins. PMID:21209173

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

    PubMed

    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

  1. 2010 Surveillance for Aeromonas hydrophila outbreaks in the Alabama catfish industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    PubMed

    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

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

    PubMed Central

    Forn-Cuní, Gabriel; Tomás, Juan M.

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    EPA Science Inventory

    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...

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

    EPA Science Inventory

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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....

  9. Whole-Genome Sequencing Analysis of Quorum-Sensing Aeromonas hydrophila Strain M023 from Freshwater.

    PubMed

    Tan, Wen-Si; Yin, Wai-Fong; Chang, Chien-Yi; Chan, Kok-Gan

    2015-01-01

    Aeromonas hydrophila is a well-known waterborne pathogen that recently was found to infect humans. Here, we report the draft genome of a freshwater isolate from a Malaysian waterfall, A. hydrophila strain M023, which portrays N-acylhomoserine lactone-dependent quorum sensing. PMID:25700404

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

    PubMed Central

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Complete Type III Secretion System of a Mesophilic Aeromonas hydrophila Strain

    PubMed Central

    Vilches, Silvia; Urgell, Cecilia; Merino, Susana; Chacón, Matilde R.; Soler, Lara; Castro-Escarpulli, Graciela; Figueras, Maria Jose; Tomás, Juan M.

    2004-01-01

    We have investigated the existence and genetic organization of a functional type III secretion system (TTSS) in a mesophilic Aeromonas strain by initially using the Aeromonas hydrophila strain AH-3. We report for the first time the complete TTSS DNA sequence of an Aeromonas strain that comprises 35 genes organized in a similar disposition as that in Pseudomonas aeruginosa. Using several gene probes, we also determined the presence of a TTSS in clinical or environmental strains of different Aeromonas species: A. hydrophila, A. veronii, and A. caviae. By using one of the TTSS genes (ascV), we were able to obtain a defined insertion mutant in strain AH-3 (AH-3AscV), which showed reduced toxicity and virulence in comparison with the wild-type strain. Complementation of the mutant strain with a plasmid vector carrying ascV was fully able to restore the wild-type toxicity and virulence. PMID:15528564

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

    PubMed

    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

  14. [Aeromonas hydrophila in waters of Lake San Roque and its tributaries].

    PubMed

    Fracchia de Salvay, Y

    1986-01-01

    The presence of Aeromonas hydrophila in 72 samples of water of Lake San Roque and two rivers that flow into it, situated in Punilla Valley, Córdoba was investigated. Water-peptone Alkaline (enrichment medium) and Rippey Cabelli Agar without ampicillin (selective and differential medium for Aeromonas hydrophila) were used for isolation. The colonies obtained were assayed by oxidase test and subsequent oxidation-fermentation of Hugh Leifson, motility, urease, mannitol and trehalose fermentation, ornithine and lysine decarboxylation. Voges Proskauer and gas production from glucose and glycerol. Aeromonas hydrophila was isolated in 13% of water samples obtained in days with high temperature. Although this finding is not alarming, its presence should be taken into account because of its potential pathogenesis. PMID:3685388

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    EPA Science Inventory

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    PubMed

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  2. Pathogenicity of Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis to Brown Tree Frogs (Litoria ewingii)

    PubMed Central

    Schadich, Ermin; Cole, Anthony LJ

    2010-01-01

    Bacterial dermatosepticemia, a systemic infectious bacterial disease of frogs, can be caused by several opportunistic gram-negative bacterial species including Aeromonas hydrophila, Chryseobacterium indologenes, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Serratia liquifaciens. Here we determined the pathogenicity of 3 bacterial species (Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis) associated with an outbreak of fatal dermatosepticemia in New Zealand Litoria ewingii frogs. A bath challenge method was used to expose test frogs to individual bacterial species (2 × 107 cfu/mL in pond water); control frogs were exposed to uninfected pond water. None of the control frogs or those exposed to A. hydrophila or P. mirabilis showed any morbidity or mortality. Morbidity and mortality was 40% among frogs exposed to K. pneumonia, and the organism was reisolated from the hearts, spleens, and livers of affected animals. PMID:20412685

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

    PubMed Central

    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 cutaneous ulcerations on the lip, right forelimb, and ventral chest. Microscopic findings included regionally extensive splenic necrosis, diffuse pneumonia, and fibrinous coelomitis all containing intralesional bacteria. PCR analysis yielded positive results for B. dendrobatidis only. Bacterial culture of the ulcerated skin and liver yielded A. hydrophila. Infection with Contracaecum spp. was diagnosed as an incidental finding. To our knowledge, this case is the first report of simultaneous infection with Aeromonas hydrophila, Mycobacterium spp., and Batrachochytrium dendrobatidis in a laboratory-maintained X. laevis captured from the wild. PMID:20353698

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

    PubMed

    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

  5. Inactivation of Aeromonas hydrophila by Fe(II)-related-radical generation in oxidizing groundwaters.

    PubMed Central

    Kersters, I; Verstraete, W

    1996-01-01

    The survival of Aeromonas hydrophila AWWX1 in filter-sterilized phreatic groundwaters was studied by using viable counts. Aeromonas counts rapidly decreased 2 to 3 log units in oxidizing raw groundwaters from Snellegem and Beernem, Belgium (Snellegem-raw and Beernem-raw, respectively), containing high concentrations of Fe2+ (460 to 1,070 microM). The rapid decline in viable counts of Aeromonas cells in the oxidizing raw groundwater of Snellegem was prevented by the addition of an Fe2+ chelator (2,2'-dipyridyl) or compounds (i.e., ascorbic acid and catalase) that act on toxic oxygen species. The results suggest that free radicals, generated spontaneously in oxidizing Fe2+-containing groundwaters, caused the inactivation of A. hydrophila AWWX1. Evidence that free radicals are generated under the given conditions was provided by the observation that propylphosphonic acid, a compound which is very susceptible to radicals, was degraded upon addition to these waters. A. hydrophila PWBS, Pseudomonas fluorescens P17, Spirillum strain NOX, and heterotrophs showed decreases in culturability in filter-sterilized Snellegem-raw water similar to that shown by A. hydrophila AWWX1. These findings indicate that free radicals generated in Fe2+-containing groundwaters upon aeration are capable of inactivating various bacterial species. PMID:8795217

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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

  9. [Aeromonas hydrophila pneumonia associated with a traffic accident. Report of a case].

    PubMed

    Vázquez Piloto, A; González Ramírez, A N; Cruz Robaina, J C; Monté Boada, R J; Bravo Fariñas, L; Alvarez Medina, A M

    1996-01-01

    The case of a patient who was driving a car after getting drunk is presented. His car turned over and he fell into an irrigation canal, and, as a result, he suffered from an incomplete drowning syndrome. He was admitted in the Intensive Care Unit with acute inflammatory pneumonia and a strain of Aeromonas hydrophila was isolated in blood. The patient's evolution was favorable. It is the first report on a case like this in our country. PMID:9768270

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

    PubMed

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Evidence for bacterial chemotaxis to cyanobacteria from a radioassay technique. [Lyngbya birgei; Aphanizomenon flos-aquae; Aeromonas hydrophila

    SciTech Connect

    Kangatharalingam, N.; Wang, Lizhu; Priscu, J.C. )

    1991-08-01

    Lyngbya birgei and Aphanizomenon flos-aquae elicited a significant chemotactic attraction of Aeromonas hydrophila compared with controls lacking cyanobacteria. There was a positive exponential relationship between biomass (chlorophyll a) of L. birgei and A. flos-aquae and chemotactic attraction of A. hydrophila. The assay equipment was simple and reliable and could be used to study bacterial chemotaxis in other species in situ.

  13. Insights into the Quorum-Sensing Activity in Aeromonas hydrophila Strain M013 as Revealed by Whole-Genome Sequencing.

    PubMed

    Tan, Wen-Si; Yin, Wai-Fong; Chan, Kok-Gan

    2015-01-01

    Aeromonas hydrophila species can be found in warm climates and can survive in different environments. They possess the ability to communicate within their populations, which is known as quorum sensing. In this work, we present the draft genome sequence of A. hydrophila M013, a bacterium isolated from a Malaysian tropical rainforest waterfall. PMID:25555739

  14. Development and validation of glycoprotein-based native-subunit vaccine for fish against Aeromonas hydrophila.

    PubMed

    Çiftci, A; Onuk, E E; Çiftci, G; Fındık, A; Söğüt, M Ü; Didinen, B I; Aksoy, A; Üstünakın, K; Gülhan, T; Balta, F; Altun, S

    2016-08-01

    Aeromonas hydrophila is known to be causative agent of an infection named as Bacterial haemorrhagic septicaemia or red pest in freshwater fish. The aim of this study was to develop and validate the glycoprotein-based fish vaccine against Aeromonas hydrophila. For this aim, after identification and characterization of A. hydrophila isolates from fish farms, one A. hydrophila isolate was selected as vaccine strain. Antigenic glycoproteins of this vaccine strain were determined by Western blotting and glycan detection kit. The connection types of these glycoproteins were examined by glycoprotein differentiation kit. Two glycoproteins, molecular weights of 19 and 38 kDa, with SNA connection type were selected for use in vaccination trials. After their purification by SNA-specific lectin and size-exclusion chromatography, protection studies with purified proteins were performed. For challenge trials, four experimental fish groups were designated: Group I (with montanide), Group II (with montanide and ginseng), Group III [with Al(OH)3 ] and Group IV [with Al(OH)3 and ginseng]. The survival ratings of fish were determined, and protection was calculated as 21.56%, 29.41%, 69.83% and 78.88% in groups I, II, III and IV, respectively. In conclusion, A. hydrophila glycoproteins with Al(OH)3 and ginseng could be used as a safe and effective vaccine for fish. PMID:27144782

  15. Complete genome sequence of the highly virulent Aeromonas hydrophila AL09-71 isolated from disease channel catfish from West Alabama

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. The response of New-season Nile tilapia to Aeromonas hydrophila vaccine

    PubMed Central

    Aly, Salah M; Albutti, Aqel S; Rahmani, Arshad H; Atti, Nashwa M Abdel

    2015-01-01

    The present study was conducted to recognize the response of new-season Nile tilapia to Aeromonas hydrophila vaccine. Four hundred new-season Nile tilapia were used in this study and divided into two equal groups, the first group served as control and the 2nd group was vaccinated with Aeromonas hydrophila vaccine via intraperitoneal injection. The antibody titer, Hematocrit level (HCV), Nitroblue tetrazolium activity (NBT) and lysozyme activity of new-season Nile tilapia was measured at the end of the 1st, 2nd, 3rd, 4th, 6th, 8th and 10th week post vaccination (PV). Challenge with A. hydrophila was carried out at the end of the 6th, 8th and 10th week PV. The antibody titer of vaccinated new-season tilapia showed significant higher values than unvaccinated group at all periods. The hematocrit and lysozymes activity values showed, a non significant increased in comparison with unvaccinated group at all periods PV. The NBT was significantly increased in vaccinated tilapia in comparison with unvaccinated group at all periods except one week PV. The relative level of protection of vaccinated tilapia after challenge infection was highest at 6th week PV in the new-season tilapia. We conclude that, vaccination against A. hydrophila increase the resistance of tilapia to such infection and consequently improve the survival and economic outcome. Other more applicable routes of vaccination should be investigated to be used on a large scale. PMID:26064376

  17. Amonabactin, a novel tryptophan- or phenylalanine-containing phenolate siderophore in Aeromonas hydrophila.

    PubMed Central

    Barghouthi, S; Young, R; Olson, M O; Arceneaux, J E; Clem, L W; Byers, B R

    1989-01-01

    Aeromonas hydrophila 495A2 excreted two forms of amonabactin, a new phenolate siderophore composed of 2,3-dihydroxybenzoic acid, lysine, glycine, and either tryptophan (amonabactin T) or phenylalanine (amonabactin P). Supplementing cultures with L-tryptophan (0.3 mM) caused exclusive synthesis of amonabactin T, whereas supplements of L-phenylalanine (0.3 to 30 mM) gave predominant production of amonabactin P. The two forms of amonabactin were separately purified by a combination of production and polyamide column chromatographic methods. Both forms were biologically active, stimulating growth in iron-deficient medium of an amonabactin-negative mutant. Of 43 additional siderophore-producing isolates of the Aeromonas species that were tested, 76% (19 of 25) of the A. hydrophila isolates were amonabactin positive, whereas only 19% (3 of 16) of the A. sobria isolates and all (3 of 3) of the A. caviae isolates produced amonabactin, suggesting a predominant synthesis of amonabactin in certain Aeromonas species. PMID:2522922

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

    PubMed

    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

  19. Impact of thermal loading and other water quality parameters on the epizootiology of Aeromonas hydrophila infections of centrarchids. Final report

    SciTech Connect

    Esch, G.W.; Hazen, T.C.

    1983-01-01

    Red-sore disease is a rather recent problem for those involved in the sport and commercial fishing industries in the southeastern United States. The causative, or etiological, agent for red-sore disease is the widespread and commonly occurring bacterium, Aeromonas hydrophila. The disease is characterized by both external and internal lesions with serious damage to internal organs ultimately causing death of the host. Evidence points to the existence of several strains of Aeromonas hydrophila with some more virulent than others. The prevalence of the disease is related to elevated water temperature and body condition.

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

    PubMed Central

    Shi, Guo-Qing; Tang, Guang-Peng; Zou, Zhi-Tin; Yao, Guang-Hai; Zeng, Guang

    2012-01-01

    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 ≥ 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. PMID:23908938

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

    PubMed

    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

  2. Class 1 integrons in Aeromonas hydrophila isolates from farmed Nile tilapia (Oreochromis nilotica).

    PubMed

    Lukkana, Mintra; Wongtavatchai, Janenuj; Chuanchuen, Rungtip

    2012-04-01

    The aim of this study was to determine antimicrobial resistance of Aeromonas hydrophila isolated from farmed Nile Tilapia. A total of 50 A. hydrophila isolates from clinical cases were screened for the presence of class 1, 2 and 3 integrons and all the strains resistant to enrofloxacin and/or ciprofloxacin (n=19) examined for mutation in the quinolone resistance-determining regions (QRDRs) of gyrA and parC. The intI1 gene was detected in 23 A. hydrophila strains (46%) but no intl2 and intl3 were detected. Among these, 14 isolates (60.8%) carried gene cassettes inserted in variable regions i.e., partial aadA2, aadA2, dfrA1-orfC and dfrA12-aadA2, of which the most common gene cassette array was dfrA12-aadA2 (26.09%). Conjugal transfer of class 1 integrons with resistance gene array was detected. All the A. hydrophila strains resistant to enrofloxacin and/or ciprofloxacin possessed mutations in the QRDRs of gyrA and parC. Only a Ser-83-Ile substitution was identified in GyrA and only a Ser-80-Ile amino change was found in ParC. The data confirms that A. hydrophila from farm-raised Nile Telapia serve as a reservoir for antimicrobial resistance determinants. PMID:22123307

  3. Aeromonas hydrophila-associated skin lesions and septicaemia in a Nile crocodile (Crocodylus niloticus).

    PubMed

    Turutoglu, H; Ercelik, S; Corlu, M

    2005-03-01

    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 lesions of varying size. These lesions were mostly scattered over the abdomen and occasionally on the tail and feet. At necropsy, numerous white, multifocal and randomly distributed areas were seen on the liver. Gram-stained smears from skin and liver lesions showed Gram-negative bacilli arranged in clusters. Pure cultures of A. hydrophila were recovered from skin, internal organs and blood. Isolates were found to be susceptible to ceftiofur, amoxicillin + clavulanic acid, oxytetracycline, enrofloxacin, danofloxacin, neomycin, gentamicin, and lincomycin + neomycin. A pathogenicity test was performed using this isolate on 4 male 2-year-old New Zealand white rabbits. Local abscesses formed in 2 rabbits injected subcutaneously and the 2 that were injected intraperitoneally died as a result of septicaemia. In conclusion, this report has shown that A. hydrophila may cause skin lesions and even death due to septicaemia in crocodiles. PMID:15900900

  4. Growth of Aeromonas hydrophila on fresh vegetables stored under a controlled atmosphere.

    PubMed

    Berrang, M E; Brackett, R E; Beuchat, L R

    1989-09-01

    The effects of controlled-atmosphere storage (CAS) on the survival and growth of Aeromonas hydrophila on fresh asparagus, broccoli, and cauliflower were examined. Two lots of each vegetable were inoculated with A. hydrophila 1653 or K144. A third lot served as an uninoculated control. Following inoculation, vegetables were stored at 4 or 15 degrees C under a CAS system previously shown to extend the shelf life of each commodity or under ambient air. Populations of A. hydrophila were enumerated on the initial day of inoculation and at various intervals for 10 days (15 degrees C) or 21 days (4 degrees C) of storage. Direct plating of samples with selective media was used to enumerate A. hydrophila. The organism was detected on most lots of vegetables as they were received from a commercial produce supplier. Without exception, the CAS system lengthened the time vegetables were subjectively considered acceptable for consumption. However, CAS did not significantly affect populations of A. hydrophila which survived or grew on inoculated vegetables. PMID:2802601

  5. Novel insights into the pathogenicity of epidemic Aeromonas hydrophila ST251 clones from comparative genomics

    PubMed Central

    Pang, Maoda; Jiang, Jingwei; Xie, Xing; Wu, Yafeng; Dong, Yuhao; Kwok, Amy H. Y.; Zhang, Wei; Yao, Huochun; Lu, Chengping; Leung, Frederick C.; Liu, Yongjie

    2015-01-01

    Outbreaks in fish of motile Aeromonad septicemia (MAS) caused by Aeromonas hydrophila have caused a great concern worldwide. Here, for the first time, we provide two complete genomes of epidemic A. hydrophila strains isolated in China. To gain an insight into the pathogenicity of epidemic A. hydrophila, we performed comparative genomic analyses of five epidemic strains belonging to sequence type (ST) 251, together with the environmental strain ATCC 7966T. We found that the known virulence factors, including a type III secretion system, a type VI secretion system and lateral flagella, are not required for the high virulence of the ST251 clonal group. Additionally, our work identifies three utilization pathways for myo-inositol, sialic acid and L-fucose providing clues regarding the factors that underlie the epidemic and virulent nature of ST251 A. hydrophila. Based on the geographical distribution and biological resources of the ST251 clonal group, we conclude that ST251 is a high-risk clonal group of A. hydrophila which may be responsible for the MAS outbreaks in China and the southeastern United States. PMID:26014286

  6. Detection and genetic analysis of group II capsules in Aeromonas hydrophila.

    PubMed

    Zhang, Y L; Lau, Y L; Arakawa, E; Leung, K Y

    2003-04-01

    The genetic organization and sequences of the group II capsule gene cluster of Aeromonas hydrophila PPD134/91 have been determined previously. The purified capsular polysaccharides can increase the ability of avirulent strain PPD35/85 to survive in naive tilapia serum but have no inhibitory effect on the adhesion of PPD134/91 to carp epithelial cells. In this study, the presence of group II capsules among 33 randomly chosen A. hydrophila strains was examined by electron microscopy and genetic analysis. Ten strains were found to produce group II capsules. A PCR detection system was developed to identify two types of group II capsules (IIA and IIB) based on their genetic organization in the region II gene clusters. Group IIA capsules in the authors' collection of A. hydrophila strains are mainly found in the O : 18 and O : 34 serogroups, while group IIB capsules are found in the O : 21 and O : 27 serogroups. The presence of group II capsules in A. hydrophila strongly correlates with the serum and phagocyte survival abilities (seven out of ten strains). The results indicate that the authors' PCR detection system can constitute a reliable assay for the classification of group II capsules in A. hydrophila. PMID:12686647

  7. Aspects of constitutive and acquired antibioresistance in Aeromonas hydrophila strains isolated from water sources.

    PubMed

    Balotescu, Carmen; Israil, Anca; Radu, Roxana; Alexandru, Ionela; Dobre, Georgeta

    2003-01-01

    Over the last three decades, the literature pointed out the implications of Aeromonas species in human pathology. These species were described as being involved in intestinal (several outbreaks of acute gastroenteritis of choleric/dysenteric form or chronic diarrhoea, ulcerative colitis, etc.) in normal adults or children, as well as in extraintestinal infections in immunocompromised hosts. This last aspect included a large range of cutaneous injuries (micronecrosis, abscesses, bums, cellulites, furunculosis), joint, bones, respiratory, urinary tract, ocular infections up to meningitis, endocarditis, peritonitis, hepatobilliary disease, endotoxic shock and septicemia (as consequence of leech microvascular surgery). During the last decade, the literature reported a high mortality in Aeromonas infections determined by certain phenospecies (A. hydrophila and A. veronii) especially in extraintestinal infections in immunocompromised patients. In microbiologists' opinion this high rate of mortality was probably due to poor knowledge concerning the aspects of antibioresistance in Aeromonas strains, to empiric treatments with antibiotics to which these bacteria exhibiting constitutive resistance lead to insuccessful results, and at last to the increasing trend of aeromonads resistance to certain antibiotics after 1996. The literature mentioned also that for a great number of Beta-lactamase producing Aeromonas strains, the use of microdilution method (by comparison to disk diffusion in agar medium) giving false results made more difficult the true knowledge of Aeromonas antibioresistance patterns. At the same time, in 2002, the literature mentioned 4 ecological compartments considered as "reservoirs for dissemination and transfer of microbial antibioresistance i.e. humans, animals, plants and natural soil and water. In the last time, more and more data of the literature revealed that some bacteria with role of reservoir of antibioresistance in the natural environment, even

  8. Cloning, Sequencing, and Role in Serum Susceptibility of Porin II from Mesophilic Aeromonas hydrophila

    PubMed Central

    Nogueras, Maria Mercé; Merino, Susana; Aguilar, Alicia; Benedi, Vicente Javier; Tomás, Juan M.

    2000-01-01

    We cloned and sequenced the structural gene for Aeromonas hydrophila porin II from strain AH-3 (serogroup O:34). The genetic position of this gene, like that of ompF in Escherichia coli, is adjacent to aspC and transcribed in the same direction. However, upstream of the porin II gene no similarities with E. coli were found. We obtained defined insertion mutants in porin II gene either in A. hydrophila (O:34) or A. veronii sobria (serogroup O:11) serum-resistant or -sensitive strains. Furthermore, we complemented these mutants with a plasmid harboring only the porin II gene, which allowed us to define the role of porin II as an important surface molecule involved in serum susceptibility and C1q binding in these strains. PMID:10722573

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

    SciTech Connect

    Zhao, Minglian; Li, Zhenguo; Zheng, Wei; Lou, Zhiyong; Chen, Guo-Qiang

    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.

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

    PubMed

    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

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

    PubMed Central

    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

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

    PubMed

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Chicken-type lysozyme in channel catfish: Expression analysis, lysozyme activity and efficacy as immunostimulant against Aeromonas hydrophila infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Chicken-type lysozyme in channel catfish: expression analysis, lysozyme activity, and efficacy as immunostimulant against Aeromonas hydrophila infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Vaccination of channel catfish with extracellular products of Aeromonas hydrophila provides protection against infection by the pathogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    PubMed

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

    PubMed Central

    Lim, Yan-Lue; Roberts, Richard J.; Ee, Robson; Yin, Wai-Fong

    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

  20. THE RESPONSE OF RAINBOW TROUT 'SALMO GAIRDNERI' TO 'AEROMONAS HYDROPHILA AFTER SUBLETHAL EXPOSURES TO PCB AND COPPER

    EPA Science Inventory

    Rainbow trout were continuously exposed to sublethal PCB concentrations for 30 days and infected with Aeromonas hydrophila or sham-injected. Mortality of PCB-exposed infected fish was significantly lower than control-infected fish. Survivors of the infection at all exposure conce...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Degradation of chitin and chitosan by a recombinant chitinase derived from a virulent Aeromonas hydrophila isolated from diseased channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. Establishment of Infection Models in Zebrafish Larvae (Danio rerio) to Study the Pathogenesis of Aeromonas hydrophila.

    PubMed

    Saraceni, Paolo R; Romero, Alejandro; Figueras, Antonio; Novoa, Beatriz

    2016-01-01

    Aeromonas hydrophila is a Gram-negative opportunistic pathogen of fish and terrestrial animals. In humans, A. hydrophila mainly causes gastroenteritis, septicaemia, and tissue infections. The mechanisms of infection, the main virulence factors and the host immune response triggered by A. hydrophila have been studied in detail using murine models and adult fish. However, the great limitation of studying adult animals is that the animal must be sacrificed and its tissues/organs extracted, which prevents the study of the infectious processes in the whole living animal. Zebrafish larvae are being used for the analysis of several infectious diseases, but their use for studying the pathogenesis of A. hydrophila has never been explored. The great advantage of zebrafish larvae is their transparency during the first week after fertilization, which allows detailed descriptions of the infectious processes using in vivo imaging techniques such as differential interferential contrast (DIC) and fluorescence microscopy. Moreover, the availability of fluorescent pathogens and transgenic reporter zebrafish lines expressing fluorescent immune cells, immune marker genes or cytokines/chemokines allows the host-pathogen interactions to be characterized. The present study explores the suitability of zebrafish larvae to study the pathogenesis of A. hydrophila and the interaction mechanisms between the bacterium and the innate immune responses through an infection model using different routes for infection. We used an early-embryo infection model at 3 days post-fertilization (dpf) through the microinjection of A. hydrophila into the duct of Cuvier, caudal vein, notochord, or muscle and two bath infection models using 4 dpf healthy and injured larvae. The latter resembled the natural conditions under which A. hydrophila produces infectious diseases in animals. We compared the cellular processes after infection in each anatomical site by confocal fluorescence imaging and determined the

  4. Establishment of Infection Models in Zebrafish Larvae (Danio rerio) to Study the Pathogenesis of Aeromonas hydrophila

    PubMed Central

    Saraceni, Paolo R.; Romero, Alejandro; Figueras, Antonio; Novoa, Beatriz

    2016-01-01

    Aeromonas hydrophila is a Gram-negative opportunistic pathogen of fish and terrestrial animals. In humans, A. hydrophila mainly causes gastroenteritis, septicaemia, and tissue infections. The mechanisms of infection, the main virulence factors and the host immune response triggered by A. hydrophila have been studied in detail using murine models and adult fish. However, the great limitation of studying adult animals is that the animal must be sacrificed and its tissues/organs extracted, which prevents the study of the infectious processes in the whole living animal. Zebrafish larvae are being used for the analysis of several infectious diseases, but their use for studying the pathogenesis of A. hydrophila has never been explored. The great advantage of zebrafish larvae is their transparency during the first week after fertilization, which allows detailed descriptions of the infectious processes using in vivo imaging techniques such as differential interferential contrast (DIC) and fluorescence microscopy. Moreover, the availability of fluorescent pathogens and transgenic reporter zebrafish lines expressing fluorescent immune cells, immune marker genes or cytokines/chemokines allows the host–pathogen interactions to be characterized. The present study explores the suitability of zebrafish larvae to study the pathogenesis of A. hydrophila and the interaction mechanisms between the bacterium and the innate immune responses through an infection model using different routes for infection. We used an early-embryo infection model at 3 days post-fertilization (dpf) through the microinjection of A. hydrophila into the duct of Cuvier, caudal vein, notochord, or muscle and two bath infection models using 4 dpf healthy and injured larvae. The latter resembled the natural conditions under which A. hydrophila produces infectious diseases in animals. We compared the cellular processes after infection in each anatomical site by confocal fluorescence imaging and determined the

  5. Roles of phagocytosis activating protein (PAP) in Aeromonas hydrophila infected Cyprinus carpio.

    PubMed

    Wonglapsuwan, Monwadee; Kongmee, Pataraporn; Suanyuk, Naraid; Chotigeat, Wilaiwan

    2016-06-01

    Cyprinus carpio (koi) is one of the most popular ornamental fish. A major problem for C. carpio farming is bacterial infections especially by Aeromonas hydrophila. Previously studies had shown that the Phagocytosis Activating Protein (PAP) gene was involved in the innate immune response of animals. Therefore, we attempted to identify a role for the PAP gene in the immunology of C. carpio. The expression of the PAP was found in C. carpio whole blood and increased when the fish were stimulated by inactivated A. hydrophila. In addition, PAP-phMGFP DNA was injected as an immunostimulant. The survival rate and the phagocytic index were significantly increased in the A. hydrophila infected fish that received the PAP-phMGFP DNA immunostimulant. A chitosan-PAP-phMGFP nanoparticle was then developed and feeded into fish which infected with A. hydrophila. These fish had a significantly lower mortality rate than the control. Therefore, this research confirmed a key role for PAP in protection fish from bacterial infection and the chitosan-PAP-phMGFP nanoparticle could be a good prototype for fish immunostimulant in the future. PMID:26748248

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

    EPA Science Inventory

    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...

  7. The Type III Secretion System and Cytotoxic Enterotoxin Alter the Virulence of Aeromonas hydrophila

    PubMed Central

    Sha, Jian; Pillai, Lakshmi; Fadl, Amin A.; Galindo, Cristi L.; Erova, Tatiana E.; Chopra, Ashok K.

    2005-01-01

    Many gram-negative bacteria use a type III secretion system (TTSS) to deliver effector proteins into host cells. Here we report the characterization of a TTSS chromosomal operon from the diarrheal isolate SSU of Aeromonas hydrophila. We deleted the gene encoding Aeromonas outer membrane protein B (AopB), which is predicted to be involved in the formation of the TTSS translocon, from wild-type (WT) A. hydrophila as well as from a previously characterized cytotoxic enterotoxin gene (act)-minus strain of A. hydrophila, thus generating aopB and act/aopB isogenic mutants. The act gene encodes a type II-secreted cytotoxic enterotoxin (Act) that has hemolytic, cytotoxic, and enterotoxic activities and induces lethality in a mouse model. These isogenic mutants (aopB, act, and act/aopB) were highly attenuated in their ability to induce cytotoxicity in RAW 264.7 murine macrophages and HT-29 human colonic epithelial cells. The act/aopB mutant demonstrated the greatest reduction in cytotoxicity to cultured cells after 4 h of infection, as measured by the release of lactate dehydrogenase enzyme, and was avirulent in mice, with a 90% survival rate compared to that of animals infected with Act and AopB mutants, which caused 50 to 60% of the animals to die at a dose of three 50% lethal doses. In contrast, WT A. hydrophila killed 100% of the mice within 48 h. The effects of these mutations on cytotoxicity could be complemented with the native genes. Our studies further revealed that the production of lactones, which are involved in quorum sensing (QS), was decreased in the act (32%) and aopB (64%) mutants and was minimal (only 8%) in the act/aopB mutant, compared to that of WT A. hydrophila SSU. The effects of act and aopB gene deletions on lactone production could also be complemented with the native genes, indicating specific effects of Act and the TTSS on lactone production. Although recent studies with other bacteria have indicated TTSS regulation by QS, this is the first

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

    PubMed Central

    Suarez, Giovanni; Sierra, Johanna C.; Sha, Jian; Wang, Shaofei; Erova, Tatiana E.; Fadl, Amin A.; Foltz, Sheri M.; Horneman, Amy J.; Chopra, Ashok K.

    2008-01-01

    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. hydrophila infections was subsequently delineated in in vitro and in vivo models. In this study, we characterized the new type 6 secretion system (T6SS) from isolate SSU of A. hydrophila and demonstrated its role in bacterial virulence. Study of the role of T6SS in bacterial virulence is in its infancy, and there are, accordingly, only limited, recent reports directed toward a better understanding its role in bacterial pathogenesis. We have provided evidence that the virulence-associated secretion (vas) genes vasH (Sigma 54-dependent transcriptional regulator) and vasK (encoding protein of unknown function) are essential for expression of the genes encoding the T6SS and/or they constituted important components of the T6SS. Deletion of the vasH gene prevented expression of the potential translocon hemolysin coregulated protein (Hcp) encoding gene from bacteria, while the vasK gene deletion prevented secretion but not translocation of Hcp into host cells. The secretion of Hcp was independent of the T3SS and the flagellar system. We demonstrated that secreted Hcp could bind to the murine RAW 264.7 macrophages from outside, in addition to its ability to be translocated into host cells. Further, the vasH and vasK mutants were less toxic to murine macrophages and human epithelial HeLa cells, and these mutants were more efficiently phagocytosed by macrophages. We also provided evidence that the expression of the hcp gene in the HeLa cell resulted in apoptosis of the host cells. Finally, the vasH and vasK mutants of A. hydrophila were less virulent in a septicemic mouse model of infection, and animals immunized with recombinant Hcp were protected from subsequent challenge with the wild-type (WT

  9. Biofilm formation by Aeromonas hydrophila on green-leafy vegetables: cabbage and lettuce.

    PubMed

    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) increased with contact time; however, no significant (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

  10. Functional Genomic Characterization of Virulence Factors from Necrotizing Fasciitis-Causing Strains of Aeromonas hydrophila

    PubMed Central

    Grim, Christopher J.; Kozlova, Elena V.; Ponnusamy, Duraisamy; Fitts, Eric C.; Sha, Jian; Kirtley, Michelle L.; van Lier, Christina J.; Tiner, Bethany L.; Erova, Tatiana E.; Joseph, Sandeep J.; Read, Timothy D.; Shak, Joshua R.; Joseph, Sam W.; Singletary, Ed; Felland, Tracy; Baze, Wallace B.; Horneman, Amy J.

    2014-01-01

    The genomes of 10 Aeromonas isolates identified and designated Aeromonas hydrophila WI, Riv3, and NF1 to NF4; A. dhakensis SSU; A. jandaei Riv2; and A. caviae NM22 and NM33 were sequenced and annotated. Isolates NF1 to NF4 were from a patient with necrotizing fasciitis (NF). Two environmental isolates (Riv2 and -3) were from the river water from which the NF patient acquired the infection. While isolates NF2 to NF4 were clonal, NF1 was genetically distinct. Outside the conserved core genomes of these 10 isolates, several unique genomic features were identified. The most virulent strains possessed one of the following four virulence factors or a combination of them: cytotoxic enterotoxin, exotoxin A, and type 3 and 6 secretion system effectors AexU and Hcp. In a septicemic-mouse model, SSU, NF1, and Riv2 were the most virulent, while NF2 was moderately virulent. These data correlated with high motility and biofilm formation by the former three isolates. Conversely, in a mouse model of intramuscular infection, NF2 was much more virulent than NF1. Isolates NF2, SSU, and Riv2 disseminated in high numbers from the muscular tissue to the visceral organs of mice, while NF1 reached the liver and spleen in relatively lower numbers on the basis of colony counting and tracking of bioluminescent strains in real time by in vivo imaging. Histopathologically, degeneration of myofibers with significant infiltration of polymorphonuclear cells due to the highly virulent strains was noted. Functional genomic analysis provided data that allowed us to correlate the highly infectious nature of Aeromonas pathotypes belonging to several different species with virulence signatures and their potential ability to cause NF. PMID:24795370

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

    PubMed Central

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

    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 similar genomes. Our phylogenomic analyses suggest that U.S. catfish isolates emerged from A. hydrophila populations of Asian origin. Furthermore, we identified an A. hydrophila strain isolated in 2004 from a diseased catfish in Mississippi, prior to the onset of the major epidemic outbreaks in Alabama starting in 2009, with genomic characteristics that are intermediate between those of the Asian and Alabama fish isolates. Investigation of A. hydrophila strain virulence demonstrated that the isolate from the U.S. catfish epidemic is significantly more virulent to both channel catfish and grass carp than is the Chinese carp isolate. This study implicates the importation of fish or fishery products into the United States as the source of highly virulent A. hydrophila that has caused severe epidemic outbreaks in United States-farmed catfish and further demonstrates the potential for invasive animal species to disseminate bacterial pathogens worldwide. PMID:24895303

  12. Antibacterial Activity of Various Plants Extracts Against Antibiotic-resistant Aeromonas hydrophila

    PubMed Central

    Al Laham, Shaza Anwar; Al Fadel, Frdoos Mohammad

    2014-01-01

    Background: Aeromonas hydrophila cause one of the most important diseases in fishes and lead to economic losses, and may be contaminated human beings. Objectives: The current research aimed to investigate the anti-bacterial activity shown by the extracts prepared from different parts of Olea europea, Myrtus communis, Thymus vulgaris, Rosmarinuis officinalis, and Achillea falcata that grow in Syria against A. hydrophila that causes the most dangerous bacterial diseases in fish. Materials and Methods: The study was performed in four stages: First of all, the presence of A. hydrophila was investigated in 450 Samples of Cyprinus Carpio fish using blood agar, Trypticase soya agar, and Analytical Profile Index (API20E). Secondly, the plants extract was obtained using water, absolute alcohol, then ether using Soxhlet extraction apparatus and rotary vacuum evaporator. Thirdly, the antibacterial activity of some antibiotics on these bacteria was evaluated by disk diffusion method. Finally, the antibacterial effect of the extracts was determined by disk diffusion method. Results: The studied antibiotics showed no antibacterial activity against these bacteria, except amikacin which had an acceptable effectiveness. However, the ethanol extracts of the studied plants revealed different antibacterial effects against A. hydrophila which showed antibiotic resistant. T. vulgaris extract had the strongest effect, whereas O. europea extract had the weakest activity. The water and ether petroleum extracts had no antibacterial activities. Conclusions: Ethanol extracts of the studied plants had different antibacterial effects against antibiotic-resistant A. hydrophila. T. vulgaris had the highest activity, R. officinalis had the second, and M. communis and A. falcate were in the third place, while the O. europea had the weakest antibacterial activity. PMID:25368797

  13. Molecular and Chemical Analysis of the Lipopolysaccharide from Aeromonas hydrophila Strain AH-1 (Serotype O11)

    PubMed Central

    Merino, Susana; Canals, Rocío; Knirel, Yuriy A.; Tomás, Juan M.

    2015-01-01

    A group of virulent Aeromonas hydrophila, A. sobria, and A. veronii biovar sobria strains isolated from humans and fish have been described; these strains classified to serotype O11 are serologically related by their lipopolysaccharide (LPS) O-antigen (O-polysaccharide), and the presence of an S-layer consisting of multiple copies of a crystalline surface array protein with a molecular weight of 52 kDa in the form of a crystalline surface array which lies peripheral to the cell wall. A. hydrophila strain AH-1 is one of them. We isolated the LPS from this strain and determined the structure of the O-polysaccharide, which was similar to that previously described for another strain of serotype O11. The genetics of the O11-antigen showed the genes (wbO11 cluster) in two sections separated by genes involved in biosynthesis and assembly of the S-layer. The O11-antigen LPS is an example of an ABC-2-transporter-dependent pathway for O-antigen heteropolysaccharide (disaccharide) assembly. The genes involved in the biosynthesis of the LPS core (waaO11 cluster) were also identified in three different chromosome regions being nearly identical to the ones described for A. hydrophila AH-3 (serotype O34). The genetic data and preliminary chemical analysis indicated that the LPS core for strain AH-1 is identical to the one for strain AH-3. PMID:25874921

  14. Quorum quenching bacteria Bacillus sp. QSI-1 protect zebrafish (Danio rerio) from Aeromonas hydrophila infection.

    PubMed

    Chu, Weihua; Zhou, Shuxin; Zhu, Wei; Zhuang, Xiyi

    2014-01-01

    Quorum Sensing (QS) is a bacterial regulatory mechanism, which is responsible for controlling the expression of various biological macromolecules such as the virulence factors in a cell density-dependent manner. Disruption of the QS system of pathogens has been proposed as a new anti-infective strategy. Biodegradation of AHLs proves to be an efficient way to interrupt QS, since AHLs are the main family of QS autoinducers used in Gram negative bacteria. In this study, the effect of Bacillus sp. QSI-1 as an efficient quorum quencher on virulence factors production and biofilm formation of fish pathogen Aeromonas hydrophila was investigated. QSI-1 reduced the accumulation of AHLs but did not affect the growth of A. hydrophila YJ-1 when cocultured. In the result, the supernatant of QSI-1 showed significant inhibition of protease production (83.9%), hemolytic activity (77.6%) and biofilm formation (77.3%) in YJ-1. In biocontrol experiment, QSI-1 significantly reduced the pathogenicity of A. hydrophila strain YJ-1 in zebrafish (Danio rerio). The fish fed with QSI-1 was observed to have a relative percentage survival of 80.8%. Our results indicate that AHLs degrading bacteria should be considered as an alternative for antibiotics in aquaculture for the biocontrol of bacterial fish diseases. PMID:24962441

  15. The effect of essential oils of basil on the growth of Aeromonas hydrophila and Pseudomonas fluorescens.

    PubMed

    Wan, J; Wilcock, A; Coventry, M J

    1998-02-01

    Basil essential oils, including basil sweet linalool (BSL) and basil methyl chavicol (BMC), were screened for antimicrobial activity against a range of Gram-positive and Gram-negative bacteria, yeasts and moulds using an agar well diffusion method. Both essential oils showed antimicrobial activity against most of the micro-organisms examined except Clostridium sporogenes, Flavimonas oryzihabitans, and three species of Pseudomonas. The minimum inhibitory concentration (MIC) of BMC against Aeromonas hydrophila and Pseudomonas fluorescens in TSYE broth (as determined using an indirect impedance method) was 0.125 and 2% (v/v), respectively; the former was not greatly affected by the increase of challenge inoculum from 10(3) to 10(6) cfu ml-1. Results with resting cells demonstrated that BMC was bactericidal to both Aer. hydrophila and Ps. fluorescens. The growth of Aer. hydrophila in filter-sterilized lettuce extract was completely inhibited by 0.1% (v/v) BMC whereas that of Ps. fluorescens was not significantly affected by 1% (v/v) BMC. In addition, the effectiveness of washing fresh lettuce with 0.1 or 1% (v/v) BMC on survival of natural microbial flora was comparable with that effected by 125 ppm chlorine. PMID:9633630

  16. Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

    NASA Astrophysics Data System (ADS)

    Zhang, Junjie; Zou, Wenzheng; Yan, Qingpi

    2008-08-01

    Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution (0.85%, w/v). Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection (dpi) for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase (SOD) activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.

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

    PubMed

    Griffin, Matt J; Goodwin, Andrew E; Merry, Gwenn E; Liles, Mark R; Williams, Malachi A; Ware, Cynthia; Waldbieser, Geoffrey C

    2013-07-01

    A new strain of Aeromonas hydrophila has been implicated in significant losses in farm-raised catfish. Outbreaks attributable to this new strain began in Alabama in the summer of 2009 and have spread to Arkansas and Mississippi in subsequent years. These outbreaks mostly afflicted market-sized fish and resulted in considerable losses in short periods of time. The present research was designed to develop an expeditious diagnostic procedure to detect the new strains of A. hydrophila due to the rapid onset and biosecurity concerns associated with this new disease. A discriminatory quantitative polymerase chain reaction assay was developed using gene sequences unique to the virulent strains identified in a related comparative genomic study. Using this assay, suspect colonies on a culture plate can be positively identified as the new strain within 2 hr. The assay is repeatable and reproducible with a linear dynamic range covering 8 orders of magnitude and a sensitivity of approximately 7 copies of target DNA in a 15-µl reaction. In addition, the assay is able to detect and quantify the virulent strain from catfish tissues (0.025 g), pond water (40 ml), and sediments (0.25 g) with a sensitivity limit of approximately 100 bacteria in a sample. This assay provides rapid discrimination between the new virulent strain and more common A. hydrophila and is useful for epidemiological studies involving the detection and quantification of the virulent strain in environmental samples and fish tissues. PMID:23847227

  18. Surface protein composition of Aeromonas hydrophila strains virulent for fish: identification of a surface array protein

    SciTech Connect

    Dooley, J.S.G.; Trust, T.J.

    1988-02-01

    The surface protein composition of members of a serogroup of Aeromonas hydrophila was examined. Immunoblotting with antiserum raised against formalinized whole cells of A. hydrophila TF7 showed a 52K S-layer protein to be the major surface protein antigen, and impermeant Sulfo-NHS-Biotin cell surface labeling showed that the 52K S-layer protein was the only protein accessible to the Sulfo-NHS-Biotin label and effectively masked underlying outer membrane (OM) proteins. In its native surface conformation the 52K S-layer protein was only weakly reactive with a lactoperoxidase /sup 125/I surface iodination procedure. A UV-induced rough lipopolysaccharide (LPS) mutant of TF7 was found to produce an intact S layer, but a deep rough LPS mutant was unable to maintain an array on the cell surface and excreted the S-layer protein into the growth medium, indicating that a minimum LPS oligosaccharide size required for A. hydrophila S-layer anchoring. The native S layer was permeable to /sup 125/I in the lactoperoxidase radiolabeling procedure, and two major OM proteins of molecular weights 30,000 and 48,000 were iodinated. The 48K species was a peptidoglycan-associated, transmembrane protein which exhibited heat-modifiable SDS solubilization behavior characteristic of a porin protein. A 50K major peptidoglycan-associated OM protein which was not radiolabeled exhibited similar SDS heat modification characteristics and possibly represents a second porin protein.

  19. An experimental vaccine against Aeromonas hydrophila can induce protection in rainbow trout, Oncorhynchus mykiss (Walbaum)

    USGS Publications Warehouse

    LaPatra, S.E.; Plant, K.P.; Alcorn, S.; Ostland, V.; Winton, J.

    2010-01-01

    A candidate vaccine against Aeromonas hydrophila in rainbow trout, Oncorhynchus mykiss, was developed using a bacterial lysate. To test the strength of protection, A. hydrophila challenge models were compared using injection into both the intraperitoneal (IP) cavity and the dorsal sinus (DS) with selected doses of live bacteria washed in saline or left untreated. Unlike the IP route, injection into the DS with either saline washed or unwashed cells resulted in consistent cumulative mortality and a dose response that could be used to establish a standard challenge having an LD50 of approximately 3 × 107 colony forming units per fish. Survivors of the challenge suffered significantly lower mortality upon re-challenge than naïve fish, suggesting a high level of acquired resistance was elicited by infection. Passive immunization using serum from hyper-immunized fish also resulted in significantly reduced mortality indicating protection can be transferred and that some portion of resistance may be antibody mediated. Vaccination of groups of rainbow trout with A. hydrophila lysate resulted in significant protection against a high challenge dose but only when injected along with Freund’s complete adjuvant. At a low challenge dose, mortality in all groups was low, but the bacterial lysate alone appeared to offer some protection.

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

    PubMed

    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

  1. Differential Glycosylation of Polar and Lateral Flagellins in Aeromonas hydrophila AH-3*

    PubMed Central

    Wilhelms, Markus; Fulton, Kelly M.; Twine, Susan M.; Tomás, Juan M.; Merino, Susana

    2012-01-01

    Polar and lateral flagellin proteins from Aeromonas hydrophila strain AH-3 (serotype O34) were found to be glycosylated with different carbohydrate moieties. The lateral flagellin was modified at three sites in O-linkage, with a single monosaccharide of 376 Da, which we show to be a pseudaminic acid derivative. The polar flagellin was modified with a heterogeneous glycan, comprised of a heptasaccharide, linked through the same 376-Da sugar to the protein backbone, also in O-linkage. In-frame deletion mutants of pseudaminic acid biosynthetic genes pseB and pseF homologues resulted in abolition of polar and lateral flagellar formation by posttranscriptional regulation of the flagellins, which was restored by complementation with wild type pseB or F homologues or Campylobacter pseB and F. PMID:22733809

  2. Effect of starvation on survival and virulence expression of Aeromonas hydrophila from different sources.

    PubMed

    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

  3. Aeromonas hydrophila infection complicating an open tibial fracture. A case report.

    PubMed

    Simodynes, E E; Cochran, R M

    1982-01-01

    Aeromonas hydrophila is a gram-negative bacterium that commonly inhabits soil and stagnant water. On extremely rare occasions, the organism can cause an aggressive, rapidly spreading, necrotizing infection in humans. The systemic signs of high fever, tachycardia, and elevation of the white blood cell count appear within 24 hours of wound contamination. If the wound is obscured by a cast, these signs erroneously may be attributed to a respiratory problem, e.g., atelectasis or fat metabolism. The organism is not usually sensitive to penicillin or cephalothin. The key to success for saving the extremity appears to be early aggressive debridement. Early diagnosis requires prompt wound inspection as soon as clinical signs of sepsis appear. PMID:7140058

  4. 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.

    PubMed

    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

  5. Protection of ornamental gold fish Carassius auratus against Aeromonas hydrophila by treating Ixora coccinea active principles.

    PubMed

    Anusha, Paulraj; Thangaviji, Vijayaragavan; Velmurugan, Subramanian; Michaelbabu, Mariavincent; Citarasu, Thavasimuthu

    2014-02-01

    Herbals such as Ixora coccinea, Daemia extensa and Tridax procumbens were selected to screen in vitro antibacterial and immunostimulant activity against the freshwater fish pathogen Aeromonas hydrophila using different organic polar and non-polar solvents. Initial screening results revealed that, ethyl acetate extracts and its purified fraction of I. coccinea was able to suppress the A. hydrophila strains at more than 15 mm of zone of inhibition and positive immunostimulant activity. The purified active fraction, which eluted from H40: EA60 mobile phase was structurally characterized by GC-MS analysis. Two compounds such as Diethyl Phthalate (1,2-Benzene dicarboxylic acid, monobutyl ester) and Dibutyl Phthalate were characterized using NIST database search. In order to study the in vivo immunostimulant influence of the compounds, the crude extracts (ICE) and purified fractions (ICF) were incorporated to the artificial diets at the concentration of 400 mg kg⁻¹ and fed to the ornamental gold fish Carassius auratus for 30 days. After termination of feeding experiment, they were challenged with highly virulent A. hydrophila AHV-1 which was isolated from infected gold fish and studied the survival, specific bacterial load reduction, serum biochemistry, haematology, immunology and histological parameters. The control diet fed fishes succumbed to death within five days at 100% mortality whereas ICE and ICF fed groups survived 60 and 80% respectively after 10 days. The diets also helped to decrease the Aeromonas load after challenge and significantly (P ≤ 0.01) improved the serum albumin, globulin and protein. The diets also helped to increase the RBC and haemoglobin level significantly (P ≤ 0.05) from the control group. Surprisingly the immunological parameters like phagocytic activity, serum bactericidal activity and lysozyme activity were significantly increased (P ≤ 0.001) in the experimental diets. Macrophages and erythrocytes were abundantly expressed in the

  6. Emerging pathogens: Aeromonas spp.

    PubMed

    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

  7. The FlgT Protein Is Involved in Aeromonas hydrophila Polar Flagella Stability and Not Affects Anchorage of Lateral Flagella

    PubMed Central

    Merino, Susana; Tomás, Juan M.

    2016-01-01

    Aeromonas hydrophila sodium-driven polar flagellum has a complex stator-motor. Consist of two sets of redundant and non-exchangeable proteins (PomA/PomB and PomA2/PomB2), which are homologs to other sodium-conducting polar flagellum stator motors; and also two essential proteins (MotX and MotY), that they interact with one of those two redundant pairs of proteins and form the T-ring. In this work, we described an essential protein for polar flagellum stability and rotation which is orthologs to Vibrio spp. FlgT and it is encoded outside of the A. hydrophila polar flagellum regions. The flgT was present in all mesophilic Aeromonas strains tested and also in the non-motile Aeromonas salmonicida. The A. hydrophila ΔflgT mutant is able to assemble the polar flagellum but is more unstable and released into the culture supernatant from the cell upon completion assembly. Presence of FlgT in purified polar hook-basal bodies (HBB) of wild-type strain was confirmed by Western blotting and electron microscopy observations showed an outer ring of the T-ring (H-ring) which is not present in the ΔflgT mutant. Anchoring and motility of proton-driven lateral flagella was not affected in the ΔflgT mutant and specific antibodies did not detect FlgT in purified lateral HBB of wild type strain. PMID:27507965

  8. Protective immunity of grass carp immunized with DNA vaccine against Aeromonas hydrophila by using carbon nanotubes as a carrier molecule.

    PubMed

    Liu, Lei; Gong, Yu-Xin; Liu, Guang-Lu; Zhu, Bin; Wang, Gao-Xue

    2016-08-01

    To reduce the economic losses caused by diseases in aquaculture industry, more efficient and economic prophylactic measures should be urgently investigated. In this research, the effects of a novel functionalized single-walled carbon nanotubes (SWCNTs) applied as a delivery vehicle for DNA vaccine administration in juvenile grass carp against Aeromonas hydrophila were studied. Our results showed that SWCNTs loaded with DNA vaccine induced a better protection to juvenile grass carp against A. hydrophila. Moreover, SWCNTs conjugated with DNA vaccine provided significantly protective immunity compared with free DNA vaccine. Thereby, SWCNTs may be considered as a potential efficient DNA vaccine carrier to enhance the immunological activity. PMID:27343373

  9. Effect of electron irradiation and packaging atmosphere on the survival of aeromonas hydrophila in minced poultry meat

    NASA Astrophysics Data System (ADS)

    Stecchini, M. L.; Sarais, I.; Del Torre, M.; Fuochi, P. G.

    1995-02-01

    Resistance to electron irradiation of Aeromonas hydrophila inoculated in minced poultry meat packed in presence of air or under vacuum was examined. Surviving bacteria were counted on starch ampicillin agar containing 100 μg/ml of ampicillin. Radiation resistance, expressed as D 10 values, was calculated from the survival curves and found to be 0.12 and 0.12 kGy in poultry meat packed in air or under vacuum respectively. Storage at 2°C of meat samples irradiated at 0.5 kGy further reduced the number of A. hydrophila.

  10. Pathogenicity of Aeromonas hydrophila isolated from the Malaysian Sea against coral (Turbinaria sp.) and sea bass (Lates calcarifer).

    PubMed

    Hamid, Rahimi; Ahmad, Asmat; Usup, Gires

    2016-09-01

    A study was carried out to determine the pathogenicity (hemolytic activity) on corals (Turbinaria sp.) and sea bass (Lates calcarifer) of Aeromonas hydrophila from water, sediment, and coral. Samples were collected from coastal water and coral reef areas. One hundred and sixty-two isolates were successfully isolated. Out of 162, 95 were from seawater, 49 from sediment, and 18 from coral. Sixteen isolates were picked and identified. Isolates were identified using a conventional biochemical test, the API 20NE kit, and 16S rRNA nucleotide sequences. Hemolytic activity was determined. Out of 16 isolates, 14 isolates were β-hemolytic and two isolates were non-hemolytic. Corals infected with A. hydrophila suffered bleaching. Similar effect was observed for both hemolytic and non-hemolytic isolates. Intramuscular injection of A. hydrophila into sea bass resulted in muscular bleeding and death. Higher infection rates were obtained from hemolytic compared to non-hemolytic strains of A. hydrophila isolates. PMID:27221587

  11. Biological approach to synthesize TiO2 nanoparticles using Aeromonas hydrophila and its antibacterial activity

    NASA Astrophysics Data System (ADS)

    Jayaseelan, Chidambaram; Rahuman, Abdul Abdul; Roopan, Selvaraj Mohana; Kirthi, Arivarasan Vishnu; Venkatesan, Jayachandran; Kim, Se-Kwon; Iyappan, Moorthy; Siva, Chinnadurai

    2013-04-01

    Nanosized materials have been an important subject in basic and applied sciences. A novel, low-cost, green and reproducible bacteria, Aeromonas hydrophila mediated biosynthesis of titanium dioxide nanoparticles (TiO2 NPs) was reported. The resulting nanoparticles were characterized by FTIR, XRD, AFM and FESEM with EDX. FTIR showed characteristic bands (1643 and 3430 cm-1) finds the role of carboxyl group Osbnd H stretching amine Nsbnd H stretch in the formation of TiO2 NPs. The XRD spectrum confirmed that the synthesized TiO2 NPs were in the form of nanocrystals, as evidenced by the peaks at 2θ values of 27.47°, 31.77°, 36.11°, 41.25°, 54.39°, 56.64° and 69.54° were identified as 110, 100, 101, 111, 211, 220 and 301 reflections, respectively. The crystallite sizes were calculated using Scherrer's formula applied to the major intense peaks and found to be the size of 40.50 nm. The morphological characterization was analyzed by FESEM and the analysis showed the NPs smooth shaped, spherical and uneven. GC-MS analysis showed the main compounds found in A. hydrophila were uric acid (2.95%), glycyl-L-glutamic acid (6.90%), glycyl-L-proline (74.41%) and l-Leucyl-d-leucine (15.74%). The potential glycyl-L-proline could have played an important role as a capping agent. A possible mechanism for the biosynthesis of TiO2 NPs has been proposed. The antibacterial activity of the synthesized TiO2 NPs was assessed by well diffusion method toward A. hydrophila, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis and showed effective inhibitory activity against S. aureus (33 mm) and S. pyogenes (31 mm).

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

    PubMed

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

    2013-12-01

    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 as alternative to antibiotics. AgNPs were synthesized using the leaf extracts of subtropical plants Mangifera indica (Mango), Eucalyptus terticornis (Eucalyptus), Carica papaya (Papaya) and Musa paradisiaca (Banana). The absorbance maxima, size range and shape of the AgNPs as characterized by the UV-Vis spectroscopy, high resolution transmission electron microscopy (HR-TEM), and energy dispersive X-ray spectroscopy (EDX) were, Mangifera-442, 50-65 nm, ovular; Eucalyptus-465, 60-150 nm, oval; Carica-442, 25-40 nm, round, irregular; and Musa-454, 10-50 nm, round, irregular, respectively. Well-diffusion of these AgNPs for their antimicrobial characteristics exhibited that, the papaya leaf extract synthesized AgNPs had maximum antimicrobial activity at 153.6 μg/ml concentrations, and that from the eucalyptus leaves was least effective. As observed, the potency of the nanoparticles enhanced with the decrease in particle size, from 60-150 nm in eucalyptus to 25-40 nm in papaya. Due to its purely natural sourcing, phytosynthesized AgNPs can be applied as alternative to antibiotics and other biocides as a cost-effective and eco-friendly therapeutic agent against A. hydrophila stimulated diseases in aquatic animals. PMID:24426148

  13. Biological approach to synthesize TiO2 nanoparticles using Aeromonas hydrophila and its antibacterial activity.

    PubMed

    Jayaseelan, Chidambaram; Rahuman, Abdul Abdul; Roopan, Selvaraj Mohana; Kirthi, Arivarasan Vishnu; Venkatesan, Jayachandran; Kim, Se-Kwon; Iyappan, Moorthy; Siva, Chinnadurai

    2013-04-15

    Nanosized materials have been an important subject in basic and applied sciences. A novel, low-cost, green and reproducible bacteria, Aeromonas hydrophila mediated biosynthesis of titanium dioxide nanoparticles (TiO2 NPs) was reported. The resulting nanoparticles were characterized by FTIR, XRD, AFM and FESEM with EDX. FTIR showed characteristic bands (1643 and 3430 cm(-1)) finds the role of carboxyl group OH stretching amine NH stretch in the formation of TiO2 NPs. The XRD spectrum confirmed that the synthesized TiO2 NPs were in the form of nanocrystals, as evidenced by the peaks at 2θ values of 27.47°, 31.77°, 36.11°, 41.25°, 54.39°, 56.64° and 69.54° were identified as 110, 100, 101, 111, 211, 220 and 301 reflections, respectively. The crystallite sizes were calculated using Scherrer's formula applied to the major intense peaks and found to be the size of 40.50 nm. The morphological characterization was analyzed by FESEM and the analysis showed the NPs smooth shaped, spherical and uneven. GC-MS analysis showed the main compounds found in A. hydrophila were uric acid (2.95%), glycyl-L-glutamic acid (6.90%), glycyl-L-proline (74.41%) and L-Leucyl-D-leucine (15.74%). The potential glycyl-L-proline could have played an important role as a capping agent. A possible mechanism for the biosynthesis of TiO2 NPs has been proposed. The antibacterial activity of the synthesized TiO2 NPs was assessed by well diffusion method toward A. hydrophila, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis and showed effective inhibitory activity against S. aureus (33 mm) and S. pyogenes (31 mm). PMID:23416912

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

    PubMed

    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

  15. Random Amplified Polymorphic DNA Typing of Clinical and Environmental Aeromonas hydrophila Strains from Limpopo Province, South Africa

    PubMed Central

    Ramalivhana, J.N.; Obi, C.L.; Labuschagne, C.; Weldhagen, G.F.

    2010-01-01

    The aim of the present study was to determine the genetic relatedness of strains isolated from diarrhoeal stool and water specimens collected from water-storage containers from different geographical areas in the Limpopo province. In total, 32 Aeromonas strains isolated from stool specimens collected from HIV/AIDS patients suffering from gastroenteritis and their household drinking-water stored in 20-L and 25-L containers were analyzed by random amplified polymorphic DNA PCR (RAPD). The RAPD fingerprints obtained proved reproducible when repeated on three different occasions using whole-cell DNA isolated from the Aeromonas strains. In total, 12 unique RAPD fingerprints were found. The results revealed a tendency of the isolates to cluster according to their origin of isolation (best-cut test 0.80 and bootstrap values >50%). However, a certain degree of similarity was also observed between isolates of water sources and clinical sources which indicated genetic relatedness. There were also genetic similarities between the clinical and the environmental strains of Aeromonas spp. isolated from different geographical areas. This study has demonstrated the genetic relatedness of Aeromonas hydrophila isolates from household drinking-water and clinical sources in South Africa, which may be due to cross-contamination from water to patients or vice-versa. This observation is of public-health significance, particularly in the era of HIV/AIDS. This study points to the importance of monitoring and evaluating infection-control measures for improved hygiene and to prevent cross-contaminations. PMID:20214080

  16. Thin-film fixed-bed reactor for solar photocatalytic inactivation of Aeromonas hydrophila: influence of water quality

    PubMed Central

    2012-01-01

    Background Controlling fish disease is one of the major concerns in contemporary aquaculture. The use of antibiotics or chemical disinfection cannot provide a healthy aquaculture system without residual effects. Water quality is also important in determining the success or failure of fish production. Several solar photocatalytic reactors have been used to treat drinking water or waste water without leaving chemical residues. This study has investigated the impact of several key aspects of water quality on the inactivation of the pathogenic bacterium Aeromonas hydrophila using a pilot-scale thin-film fixed-bed reactor (TFFBR) system. Results The level of inactivation of Aeromonas hydrophila ATCC 35654 was determined using a TFFBR with a photocatalytic area of 0.47 m2 under the influence of various water quality variables (pH, conductivity, turbidity and colour) under high solar irradiance conditions (980–1100 W m-2), at a flow rate of 4.8 L h-1 through the reactor. Bacterial enumeration were obtained through conventional plate count using trypticase soy agar media, cultured in conventional aerobic conditions to detect healthy cells and under ROS-neutralised conditions to detect both healthy and sub-lethally injured (oxygen-sensitive) cells. The results showed that turbidity has a major influence on solar photocatalytic inactivation of A. hydrophila. Humic acids appear to decrease TiO2 effectiveness under full sunlight and reduce microbial inactivation. pH in the range 7–9 and salinity both have no major effect on the extent of photoinactivation or sub-lethal injury. Conclusions This study demonstrates the effectiveness of the TFFBR in the inactivation of Aeromonas hydrophila under the influence of several water quality variables at high solar irradiance, providing an opportunity for the application of solar photocatalysis in aquaculture systems, as long as turbidity remains low. PMID:23194331

  17. Effect of dietary astaxanthin against Aeromonas hydrophila infection in common carp, Cyprinus carpio.

    PubMed

    Jagruthi, Chandrasekar; Yogeshwari, Govintharaj; Anbazahan, Sannasi Muthu; Mari, Lourthu Samy Shanthi; Arockiaraj, Jesu; Mariappan, Pitchaimuthu; Sudhakar, Gunamoni Rajam Learnal; Balasundaram, Chellam; Harikrishnan, Ramasamy

    2014-12-01

    The effect of astaxanthin at 0, 25, 50, and 100 mg kg(-1) incorporated in basal feed on immune response and disease resistance in Cyprinus carpio against Aeromonas hydrophila was investigated. When fed with 25 mg kg(-1) diet, the cumulative mortality was 35% whereas it was 10% and 20% with 50 and 100 mg kg(-1) diets. With all enriched diets the growth rate increased significantly from week 1 to 4 when compared with control. However, the specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER) did not vary significantly from that of the control except with 50 mg kg(-1) diet. When fed with 50 and 100 mg kg(-1) diets the red blood cells, white blood cells, hemoglobin, and hematocrit values significantly increased. However, the serum total protein, albumin, and globulin contents significantly increased only when fed with 50 and 100 mg kg(-1) diets. The phagocytic ratio also significantly raised with 50 and 100 mg kg(-1) diets on week 2 and 4 whereas the phagocytic index significantly increased with all groups only on fourth week. The respiratory burst activity significantly increased in 25 mg kg(-1) diet group on first week whereas in 50 and 100 mg kg(-1) diet groups the activity increased on weeks 2 and 4; a similar trend was observed in the anti-protease activity only on weeks 2 and 4. The serum lysozyme activity and bactericidal activity registered a significant increase with all enriched diets. This study suggests that supplementation of astaxanthin at 50 and 100 mg kg(-1) with the basal diet significantly promotes the growth restores hematology and modulates the immune system in C. carpio against A. hydrophila. PMID:25462460

  18. Ecofriendly biosorption of dyes and metals by bacterial biomass of Aeromonas hydrophila RC1.

    PubMed

    Busi, Siddhardha; Chatterjee, Rahul; Rajkumari, Jobina; Hnamte, Sairengpuii

    2016-03-01

    The ability of dried bacterial biomass in azo dye and heavy metal removal from aqueous solution was explored. Biosorption of three textile dyes, Eriochrome black T (EBT), Acid Red 26 (AR) and Trypan blue (TB) and heavy metals (Pb and Cr) by dried biomass of Aeromonas hydrophila RC1, was investigated in a batch system under various parameters such as dye concentration, contact time, concentration of biomass, pH, and temperature. The experimental results showed that the extent of biosorption for dyes increased with increase in initial concentration of dyes, biomass concentration, contact time, temperature and decreased with increase in pH. The experimental isotherms data were analyzed using Langmuir and Freundlich isotherm equations. The Langmuir model yielded good fit to the experimental data (R² approximately 0.794, 0.844 and 0.969 for the dyes, EBT, AR and TB, respectively) with maximum monolayer adsorption capacity of 58.8 mg g⁻¹ for AR. Similarly results were obtained for heavy metals and the data fit in Langmuir model (R² value of 0.849 and 0.787) with q(m) value of 40 mg g⁻¹ for Pb. The results fit in pseudo first order kinetics with removal upto 96.67 % for Pb. Involvement of the surface characteristics of the biomass in biosorption was studied using scanning electron micrographs, FTIR, EDX and XRD analysis. Thus, use ofA. hydrophila RC1 biomass can be extensively employed in water treatment plants in order to get desired water quality in the most economical way. PMID:27097447

  19. Effect of Euphorbia hirta plant leaf extract on immunostimulant response of Aeromonas hydrophila infected Cyprinus carpio

    PubMed Central

    Sukumaran, NatarajaPillai

    2014-01-01

    The main objective of the present study is to improve the immune power of Cyprinus carpio by using Euphorbia hirta plant leaf extract as immunostimulants. The haematological, immunological and enzymatic studies were conducted on the medicated fish infected with Aeromonas hydrophila pathogen. The results obtained from the haematological studies show that the RBC count, WBC count and haemoglobin content were increased in the infected fish at higher concentration of leaf extract. The feeds with leaf extract of Euphorbia hirta were able to stimulate the specific immune response by increasing the titre value of antibody. It was able to stimulate the antibody production only up to the 5th day, when fed with higher concentrations of (25 g and 50 g) plant leaf extract. The plant extract showed non-specific immune responses such as lysozyme activity, phagocytic ratio, NBT assay, etc. at higher concentration (50 g) and in the same concentration (50 g), the leaf extract of Euphorbia hirta significantly eliminated the pathogen in blood and kidney. It was observed that fish have survival percentage significantly at higher concentration (50 g) of Euphorbia hirta, when compared with the control. The obtained results are statistically significant at P < 0.05 and P < 0.01 levels. This research work suggests that the plant Euphorbia hirta has immunostimulant activity by stimulating both specific and non-specific immunity at higher concentrations. PMID:25405077

  20. Growth of Aeromonas hydrophila at Low Concentrations of Substrates Added to Tap Water

    PubMed Central

    van der Kooij, D.; Visser, A.; Hijnen, W. A. M.

    1980-01-01

    The ability of an Aeromonas hydrophila isolate obtained from filtered river water to grow at low substrate concentrations was studied in batch experiments with tap water supplied with low concentrations of substrates. Growth was assessed by colony count determinations. The isolate only multiplied in the used tap water (2 to 3 mg of dissolved organic carbon per liter) after the addition of a small amount of an assimilable carbon compound. d-Glucose especially caused growth of the organism even at initial concentrations below 10 μg of C per liter. At initial glucose concentrations below the Ks value (12 μg of C per liter), generation times and yield (colony-forming units per milligram of substrate-C) were nonlinear with 1/initial glucose concentrations and initial glucose concentrations, respectively. From these observations, the maintenance coefficient m was calculated (m = 0.015 mg of glucose per mg [dry wt] per h at 12°C). At initial concentrations below the Ks value of starch (73 μg of C per liter), no growth was observed, but complete use of starch occurred in these situations after the addition of 10 μg of glucose-C per liter. The results of this study show that information of ecological significance may be obtained by very simple batch experiments. Moreover, the isolate studied may be used in growth experiments to assess the maximum concentration of glucose which might be present in water, particularly tap water. PMID:16345582

  1. Inactivation kinetics of various chemical disinfectants on Aeromonas hydrophila planktonic cells and biofilms.

    PubMed

    Jahid, Iqbal Kabir; Ha, Sang-Do

    2014-05-01

    The present article focuses on the inactivation kinetics of various disinfectants including ethanol, sodium hypochlorite, hydrogen peroxide, peracetic acid, and benzalkonium chloride against Aeromonas hydrophila biofilms and planktonic cells. Efficacy was determined by viable plate count and compared using a modified Weibull model. The removal of the biofilms matrix was determined by the crystal violet assay and was confirmed by field-emission scanning electron microscope. The results revealed that all the experimental data and calculated Weibull α (scale) and β (shape) parameters had a good fit, as the R(2) values were between 0.88 and 0.99. Biofilms are more resistant to disinfectants than planktonic cells. Ethanol (70%) was the most effective in killing cells in the biofilms and significantly reduced (p<0.05) the biofilms matrix. The Weibull parameter b-value correlated (R(2)=0.6835) with the biofilms matrix removal. The present findings deduce that the Weibull model is suitable to determine biofilms matrix reduction as well as the effectiveness of chemical disinfectants on biofilms. The study showed that the Weibull model could successfully be used on food and food contact surfaces to determine the exact contact time for killing biofilms-forming foodborne pathogens. PMID:24552163

  2. Protein export by a gram-negative bacterium: production of aerolysin by Aeromonas hydrophila.

    PubMed Central

    Howard, S P; Buckley, J T

    1985-01-01

    The synthesis and export of aerolysin, an extracellular protein toxin released by the gram-negative bacterium Aeromonas hydrophila, was studied by pulse-labeling with [35S]methionine. The toxin was synthesized as a higher-molecular-weight precursor. This was processed cotranslationally, resulting in the appearance within the cell of the mature protein, which was then exported to the supernatant. Precursor aerolysin accumulated in cells incubated in the presence of carbonyl cyanide m-chlorophenyl hydrazone, a substance which also inhibited the export of mature aerolysin from the cell. The entrapped mature toxin could not be shocked from the cells, although it could be digested by protease applied to shocked cells. The toxin was processed and translocated across the inner membrane of pleiotropic export mutants and accumulated in the periplasm. The results indicate that more than one step is required for the export of the protein and that aerolysin does not cross the inner and outer membranes simultaneously. Images PMID:3972770

  3. Effect of Plasma Processing and Organosilane Modifications of Polyethylene on Aeromonas hydrophila Biofilm Formation

    PubMed Central

    2014-01-01

    The aim of our research was to study how the modifications of polyethylene—a material commonly used in medicine and water industry—influence bacterial cell attachment and biofilm formation. The native surface was activated and modified using two-step process consisting in the activation of native surface with a H2O vapor plasma followed by its treatment with various organosilanes, namely, [3(tertbutylamine-2hydroxy) propyloxypropyl] diethoxymethylsilane, 1H,1H,2H,2H-perfluorooctylmethyldimethoxysilane, dimethoxydimethylsilane, and isobutylmethyldimethoxysilane. The effect of polyethylene modification after chemical treatment was analyzed using surface tension measurement. The adhesive properties of Aeromonas hydrophila LOCK0968 were studied in water with a low concentration of organic compounds, using luminometric and microscopic methods, and the viability of the adhered bacterial cells was evaluated using the colony forming units method. After two-week incubation the chemically modified materials exhibited better antiadhesive and antibacterial characteristics in comparison to the native surface. Among the examined modifying agents, dimethoxydimethylsilane showed the best desired properties. PMID:24605323

  4. Effect of plasma processing and organosilane modifications of polyethylene on Aeromonas hydrophila biofilm formation.

    PubMed

    Kregiel, Dorota; Niedzielska, Kamila

    2014-01-01

    The aim of our research was to study how the modifications of polyethylene--a material commonly used in medicine and water industry--influence bacterial cell attachment and biofilm formation. The native surface was activated and modified using two-step process consisting in the activation of native surface with a H2O vapor plasma followed by its treatment with various organosilanes, namely, [3(tertbutylamine-2hydroxy) propyloxypropyl] diethoxymethylsilane, 1H,1H,2H,2H-perfluorooctylmethyldimethoxysilane, dimethoxydimethylsilane, and isobutylmethyldimethoxysilane. The effect of polyethylene modification after chemical treatment was analyzed using surface tension measurement. The adhesive properties of Aeromonas hydrophila LOCK0968 were studied in water with a low concentration of organic compounds, using luminometric and microscopic methods, and the viability of the adhered bacterial cells was evaluated using the colony forming units method. After two-week incubation the chemically modified materials exhibited better antiadhesive and antibacterial characteristics in comparison to the native surface. Among the examined modifying agents, dimethoxydimethylsilane showed the best desired properties. PMID:24605323

  5. Aeromonas hydrophila Beta-Hemolysin Induces Active Chloride Secretion in Colon Epithelial Cells (HT-29/B6)

    PubMed Central

    Epple, H. J.; Mankertz, J.; Ignatius, R.; Liesenfeld, O.; Fromm, M.; Zeitz, M.; Chakraborty, T.; Schulzke, J. D.

    2004-01-01

    The diarrheal mechanisms in Aeromonas enteritis are not completely understood. In this study we investigated the effect of aeromonads and of their secretory products on ion secretion and barrier function of monolayers of human intestinal cells (HT-29/B6). Ion secretion was determined as a short-circuit current (ISC) of HT-29/B6 monolayers mounted in Ussing-type chambers. Transepithelial resistance (Rt) served as a measure of permeability. A diarrheal strain of Aeromonas hydrophila (strain Sb) added to the mucosal side of HT-29/B6 monolayers induced a significant ISC (39 ± 3 μA/cm2) and decreased the Rt to ∼10% of the initial value. A qualitatively identical response was obtained with sterile supernatant of strain Sb, and Aeromonas supernatant also induced a significant ISC in totally stripped human colon. Tracer flux and ion replacement studies revealed the ISC to be mainly accounted for by electrogenic Cl− secretion. Supernatant applied serosally completely abolished basal ISC. The supernatant-induced ISC was inhibited by the protein kinase C inhibitor chelerythrine, whereas a protein kinase A inhibitor (H8) and a Ca2+ chelator (BAPTA-AM) had no effect. Physicochemical properties indicated that the supernatant's active compound was an aerolysin-related Aeromonas beta-hemolysin. Accordingly, identical ISC and Rt responses were obtained with Escherichia coli lysates harboring the cloned beta-hemolysin gene from strain SB or the aerA gene encoding for aerolysin. Sequence comparison revealed a 64% homology between aerolysin and the beta-hemolysin cloned from Aeromonas sp. strain Sb. In conclusion, beta-hemolysin secreted by pathogenic aeromonads induces active Cl− secretion in the intestinal epithelium, possibly by channel insertion into the apical membrane and by activation of protein kinase C. PMID:15271947

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

    EPA Science Inventory

    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. ...

  7. Expression of Mx Gene in Cirrhinus mrigala (Hamilton, 1822) to OmpC Protein of Aeromonas hydrophila and Bacterial Infection.

    PubMed

    Roy, Pragyan; Panda, Soumya P; Pal, Arttatrana; Mishra, Sudhanshu S; Jayasankar, P; Das, Basanta K

    2016-02-01

    The aims of this study were to identify alternative myxovirus (Mx) stimulatory compounds in Cirrhinus mrigala and to characterize the kinetics and intensity of their stimulated responses by semi-quantitative RT-PCR. Mx transcripts were measured in C. mrigala injected with Aeromonas OmpC (outer membrane protein) at a dose 0.4 mg/fish. At day 1, day 2, day 3, day 5, day 10, day 20 and day 30, samples were collected from kidney, spleen, liver, heart brain, gill, intestine and muscle for the study of Mx transcript and housekeeping gene β-actin. Similarly, Mx gene expression was also studied in Aeromonas hydrophila-infected fish for a period of 10 days. Mx/β-actin ratio was constitutively expressed from all the organs of OmpC-vaccinated fish. The expression was significantly highest (P ≤ 0.05) in spleen, followed by liver, kidney, intestine, gill, heart, muscle and brain. The expression was highest in day 2 except spleen (on day 3) and subsequently reduced up to day 30. Control fish also showed Mx expression. Similarly, A. hydrophila-infected fish showed Mx/β-actin ratio upregulated significantly in the spleen and kidney on day 5, liver on day 2 and intestine on day 3. This study revealed that OmpC of A. hydrophila and its infection could stimulate the antiviral Mx gene of C. mrigala. PMID:26487188

  8. Skin and subcutaneous mycoses in tilapia (Oreochromis niloticus) caused by Fusarium oxysporum in coinfection with Aeromonas hydrophila.

    PubMed

    Cutuli, M Teresa; Gibello, Alicia; Rodriguez-Bertos, Antonio; Blanco, M Mar; Villarroel, Morris; Giraldo, Alejandra; Guarro, Josep

    2015-09-01

    Subcutaneous mycoses in freshwater fish are rare infections usually caused by oomycetes of the genus Saprolegnia and some filamentous fungi. To date, Fusarium infections in farmed fish have only been described in marine fish. Here, we report the presence of Fusarium oxysporum in subcutaneous lesions of Nile tilapia (Oreochromis niloticus). Histopathologic evaluation revealed granuloma formation with fungal structures, and the identity of the etiological agent was demonstrated by morphological and molecular analyses. Some of the animals died as a result of systemic coinfection with Aeromonas hydrophila. PMID:26155462

  9. A study on genetic variability of pathogenic Aeromonas hydrophila strains and the varied responses of the strains towards phyto-extracts.

    PubMed

    Balasundaram, A; Kumari, P Rathna; Kolanchinathan, P; Masilamani, V; John, George

    2013-11-01

    The present study evaluated genetic variation in Aeromonas hydrophila strains using PCR-RAPD and their varied susceptibility to phyto-extract. Four strains of Aeromonas hydrophila isolated from skin infections of common freshwater fish, Cyprinus carpio were characterized by various biochemical methods, physiological tests and PCR- RAPD. Antimicrobial activity of the leaf extracts of three medicinal plants, Ocimum sanctum, Adathoda vasica and Calendula officinalis were tested against the four strains of A. hydrophila by disc diffusion (Kirby-Bauer) method. Antagonistic effects of leaf extracts against A. hydrophila strains were assessed by co-culture method. RAPD analysis showed that all the microbes isolated from skin infection belong to the same species but there was no 100% genetic similarity among them Dendrogram constructed by UPGMA clearly supported the PCR pattern of genetic variability among the strains. This study revealed that Aeromonas hydophila exhibits genetic variability and varied susceptibility towards phyto-extracts. Results indicated that phyto-extracts offers a promising alternative to the use of antibiotics in controlling Aeromonas hydrophila. PMID:24511738

  10. Proteomics Analysis Reveals a Potential Antibiotic Cocktail Therapy Strategy for Aeromonas hydrophila Infection in Biofilm.

    PubMed

    Li, Wanxin; Yao, Zujie; Sun, Lina; Hu, Wenjie; Cao, Jijuan; Lin, Wenxiong; Lin, Xiangmin

    2016-06-01

    Antibiotic fitness and acquired resistance are the two critical factors when bacteria respond to antibiotics, and the correlations and mechanisms between these two factors remain largely unknown. In this study, a TMT-labeling-based quantitative proteomics method was used to compare the differential expression of proteins between the fitness and acquired resistance to chlortetracycline in Aeromonas hydrophila biofilm. Bioinformatics analysis showed that translation-related ribosomal proteins, such as 30s ribosome subunits, increased in both factors; fatty acid biosynthesis related proteins, such as FabB, FabD, FabG, AccA, and AccD, increased in biofilm fitness, and some pathways (including propanoate-metabolism-related protein, such as PrpB, AtoB, PflB, AcsA, PrpD, and GabT) displayed decreased abundance in acquired resistance biofilm. The varieties of selected proteins involved in fatty acid biosynthesis and propanoate metabolism were further validated by q-PCR assay or Western blotting. Furthermore, the antibiotic-resistance-function assays showed that fatty-acid biosynthesis should be a protective antibiotics-resistance mechanism and a cocktail of chlortetracycline and triclosan, a fatty-acid-biosynthesis inhibitor, exhibited more efficient antimicrobial capability than did each antibiotic individually on biofilm, specifically on chlortetracycline-sensitive biofilm. We therefore demonstrate that the up-regulation of fatty acid biosynthesis may play an important role in antibiotic resistance and suggest that a cocktail of chlortetracycline and triclosan may be a potential cocktail therapy for pathogenic infections in biofilm. PMID:27110028

  11. Lethal dose and clinical signs of Aeromonas hydrophila in Arapaima gigas (Arapaimidae), the giant fish from Amazon.

    PubMed

    Dias, Marcia K R; Sampaio, Luciana S; Proietti-Junior, Aldo A; Yoshioka, Eliane T O; Rodrigues, Dália P; Rodriguez, Anselmo F R; Ribeiro, Ricardo A; Faria, Fernando S E D V; Ozório, Rodrigo O A; Tavares-Dias, Marcos

    2016-05-30

    Aeromonas hydrophila is causing substantial economic losses in world aquaculture. This study determined the tolerance limit (LD50-96h) of A. hydrophila in Arapaima gigas, and also investigated the clinical signs after intradermal inoculation. Arapaima gigas fingerlings were inoculated intraperitoneally with 0 (control), 1.0×10(5), 1.0×10(6), 1.0×10(7), 1.0×10(9) and 1.0×10(10)CFU/mL of A. hydrophila for the determination of LD50-96h, which was 1.8×10(8)CFU/mL. In another trial with intradermal inoculation of 1.8×10(8)CFU/mL A. hydrophila, there was a 91.6% of mortality between 8 and 23h, and several clinical signs were found. As follows: depigmentation in the tegument, lesions in the tail and fins, loss of balance, reduction of respiratory movements, hemorrhagic foci, necrotic hemorrhages in the kidney, liver and swim bladder, splenomegaly, ascites in the abdominal cavity and hyperemia, enlargement of the gall bladder, among other clinical signs observed. The results showed that A. gigas has a relative tolerance to A. hydrophila when compared to other Neotropical fish species. PMID:27139024

  12. The Polymerization of Aeromonas hydrophila AH-3 O-Antigen LPS: Concerted Action of WecP and Wzy

    PubMed Central

    Merino, Susana; Gonzalez, Victor; Tomás, Juan M.

    2015-01-01

    The repeat units of heteropolymeric O antigen are synthesized at the cytosolic side of the inner bacterial membrane via the Wzx/Wzy-dependent assembly pathway. After being translocated across the membrane by Wzx, each repeat unit is polymerized by Wzy to form a glycan chain. In this study, we demonstrate the need of the corresponding enzyme transferring the initial HexNAc to undecaprenol phosphate (lipid carrier), together with the corresponding O-antigen polymerase (Wzy), to produce the Aeromonas hydrophila O:34-antigen. We suggest, the concerted action of WecA or P enzyme (UDP-HexNAc: polyprenol-P HexNAc-1-P transferase) and Wzy is involved in the mechanism responsible for the A. hydrophila O-antigen polymerization. PMID:26161781

  13. Role of Aeromonas hydrophila Flagella Glycosylation in Adhesion to Hep-2 Cells, Biofilm Formation and Immune Stimulation

    PubMed Central

    Merino, Susana; Wilhelms, Markus; Tomás, Juan M.

    2014-01-01

    Abstract: Polar flagellin proteins from Aeromonas hydrophila strain AH-3 (serotype O34) were found to be O-glycosylated with a heterogeneous heptasaccharide glycan. Two mutants with altered (light and strong) polar flagella glycosylation still able to produce flagella were previously obtained, as well as mutants lacking the O34-antigen lipopolysaccharide (LPS) but with unaltered polar flagella glycosylation. We compared these mutants, altogether with the wild type strain, in different studies to conclude that polar flagella glycosylation is extremely important for A. hydrophila adhesion to Hep-2 cells and biofilm formation. Furthermore, the polar flagella glycosylation is an important factor for the immune stimulation of IL-8 production via toll receptor 5 (TLR5). PMID:25464381

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

    PubMed Central

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

    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 diets as experiment 1 plus additional two diets with or without antibiotic. Results of experiment 1 showed that growth was unaffected by dietary levels of MFE. Treatments with the inclusion of MFE at the levels of 5 and 7 g/Kg DM had no mortality. Red blood cells (RBC), albumin, and total protein were all higher for the treatments fed MFE (5 and 7 g/Kg DM). Results of experiment 2 showed RBC, hemoglobin, hematocrit, globulin, albumin, and total protein improved with the increase in MFE in the infected fish. The dietary MFE at the level of 7 g/kg DM reduced mortality rate. In conclusion, MFE at the level of 7 g/kg DM could be a valuable dietary supplement to cure the infected fish. PMID:25574488

  15. Molecular identification and virulence of three Aeromonas hydrophila isolates cultured from infected channel catfish during a disease outbreak in West Alabama in 2009

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three isolates (AL09-71, AL09-72, and AL09-73) of Aeromonas hydrophila were cultured from infected channel catfish during a disease outbreak in West Alabama in August 2009. Sequence analysis of 16S-23S rDNA intergenic spacer region (ISR), cpn60, gyrB, and rpoD genes of the three strains revealed tha...

  16. Molecular identfication and virulence of three Aeromonas hydrophila isolates cultured from infected channel catfish during a disease outbreak in West Alabama (USA) in 2009

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three isolates (AL09-71, AL09-72, and AL09-73) of Aeromonas hydrophila were cultured from infected channel catfish during a disease outbreak in West Alabama in August 2009. Sequence analysis of 16S-23S rDNA intergenic spacer region (ISR), cpn60, gyrB, and rpoD genes of the three strains revealed tha...

  17. Identification, virulence, and mass spectrometry of toxic ECP fractions of West Alabama isolates of Aeromonas hydrophila obtained from a 2010 disease outbreak

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In West Alabama, disease outbreaks in 2009 caused by Aeromonas hydrophila have led to an estimated loss of more than $3 million. In 2010, disease outbreak occurred again in West Alabama, causing losses of hundreds of thousands of pounds of market size channel catfish. During the 2010 disease outbrea...

  18. Comparative transcriptional analysis reveals distinct expression patterns of channel catfish genes after the first infection and re-infection with Aeromonas hydrophila

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine whether transcriptional levels of channel catfish (Ictalurus punctatus) genes are differentially regulated between a first infection with Aeromonas hydrophila and a re-infection, suppression subtractive hybridization (SSH) was performed in this study using anterior kidney cDNA after the...

  19. Assessment of Aquaflor (c), copper sulfate and potassium permanganate for control of Aeromonas hydrophila and Flavobacterium columnare infection in sunshine bass, Morone chrysops female x Morone saxatilis male

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to assess different therapeutants against a mixed infection of Aeromonas hydrophila and Flavobacterium columnare in sunshine bass (SB) (Morone chrysops female x Morone saxatilis male). Experiment 1 assessed the efficacy of copper sulfate (CuSO4), florfenicol-medicated...

  20. Identification, virulence, and mass spectrometry of toxic ECP fractons of West Alabama isolates of Aeromonas hydrophila obtained from a 2010 disease outbreak

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In West Alabama, disease outbreaks in 2009 caused by Aeromonas hydrophila have led to an estimated loss of more than $3 million. In 2010, disease outbreak occurred again in West Alabama, causing losses of hundreds of thousands of pounds of market size channel catfish. During the 2010 disease outbrea...

  1. Hesperidin Inhibits Inflammatory Response Induced by Aeromonas hydrophila Infection and Alters CD4+/CD8+ T Cell Ratio

    PubMed Central

    Abuelsaad, Abdelaziz S. A.; Allam, Gamal; Al-Solumani, Adnan A. A.

    2014-01-01

    Background. Aeromonas hydrophila is an opportunistic bacterial pathogen that is associated with a number of human diseases. Hesperidin (HES) has been reported to exert antioxidant and anti-inflammatory activities. Objectives. The aim of this study was to investigate the potential effect of HES treatment on inflammatory response induced by A. hydrophila infection in murine. Methods. A. hydrophila-infected mice were treated with HES at 250 mg/kg b.wt./week for 4 consecutive weeks. Phagocytosis, reactive oxygen species production, CD4+/CD8+ T cell ratio, and CD14 expression on intestinal infiltrating monocytes were evaluated. The expression of E-selectin and intercellular adhesion molecule 1 on stimulated HUVECs and RAW macrophage was evaluated. Results. Percentage of CD4+ T cells in the intestinal tissues of infected treated mice was highly significantly increased; however, phagocytic index, ROS production, CD8+ T cells percentage, and CD14 expression on monocytes were significantly reduced. On the other hand, HES significantly inhibited A-LPS- and A-ECP-induced E-selectin and ICAM-1 expression on HUVECs and ICAM-1 expression on RAW macrophage. Conclusion. Present data indicated that HES has a potential role in the suppression of inflammatory response induced by A. hydrophila toxins through downmodulation of ROS production and CD14 and adhesion molecules expression, as well as increase of CD4+/CD8+ cell ratio. PMID:24891765

  2. Detection of type III secretion system genes in Aeromonas hydrophila and their relationship with virulence in Nile tilapia.

    PubMed

    Carvalho-Castro, G A; Lopes, C O; Leal, C A G; Cardoso, P G; Leite, R C; Figueiredo, H C P

    2010-08-26

    The goals of this study were to develop a PCR technique to detect ascV and aopB genes from the type III secretion system (T3SS), to evaluate the frequency of these genes in Aeromonas hydrophila strains isolated from diseased fish and from aquaculture environments, and to determine the relationship between the presence of these genes and virulence of A. hydrophila in Nile tilapia. The PCR assay developed here successfully detected the target genes, showing three different profiles for the strains ascV+/aopB+, ascV+/aopB-, and ascV-/aopB-. A higher frequency of ascV+/aopB+ was verified in isolates from diseased fish compared to those from aquaculture environments (P<0.05). Among 64 isolates from diseased fish, ascV+/aopB+ (62.5%) was the most frequent profile (P<0.05) and caused more intensive mortality rates. Environmental strains containing the ascV+/aopB+ profile were less virulent than isolates from clinical cases. These results suggest that the presence of a functional T3SS probably increases the virulence of A. hydrophila. The PCR technique was shown to be a specific and efficient tool for detection of T3SS, and this technique can be used for virulence typing of A. hydrophila isolates. PMID:20185253

  3. Display of ISKNV orf086 protein on the surface of Aeromonas hydrophila and its immunogenicity in Chinese perch (Siniperca chuatsi).

    PubMed

    Fu, Xiaozhe; Lin, Qiang; Liu, Lihui; Liang, Hongru; Huang, Zhibin; Li, Ningqiu

    2016-09-01

    Co-infection with infectious spleen and kidney necrosis virus (ISKNV) and Aeromonas hydrophila is becoming ever more widespread in Chinese perch (Siniperca chuatsi) aquaculture industry, so that it's necessary to develop the combined vaccine against ISKNV and A. hydrophila disease. The surface display of heterologous on bacteria using anchoring motifs from outer membranes proteins has already been explored as an effective delivery system of viral antigens. In present study, the ISKNV orf086 gene, which is verified as a protective antigen, was inserted into ompA gene cassette of A. hydrophila GYK1 strain by homologous recombination. And an ompA-orf086 fusion A. hydrophila mutant strain K28 was constructed. Then the ISKNV orf086 was verified to express on the surface of A. hydrophila K28 by RT-PCR, western blot and indirect immunofluorescence assay. Next, Chinese perch were intraperitoneally inoculated with formalin inactivated A. hydrophila k28 emulsified with ISA763 adjuvant with a dose of 9 × 10(8) CFU per fish. Transcriptional analysis of non-specific and specific immune related genes revealed that the expression levels of IRF-7, IRAK1, Mx, Viperin, Lysozyme and IgM were strongly up-regulated in Chinese perch post-inoculation. In addition, specific antibodies were detected by ELISA, and the results showed that antibody titer against ISKNV or A. hydrophila reached the highest with 1:800 or 1:1200 on 14dpv, respectively. Lymphocyte proliferation were detected by MTT methods, and the results showed that the SI values of AH-K28 vaccinated group to three different stimulators were significantly higher than those of control group. At last, protective efficacy were determined by challenge trials. The cumulative mortality rates of vaccinated groups were significantly lower than the control one (P < 0.05) after ISKNV or A. hydrophila challenge, and the relative percentage survival (RPS) value was 73.3% and 60%, respectively. This system provides a novel approach to

  4. Incidence of motile Aeromonas spp. in foods.

    PubMed

    Pin, C; Marín, M L; García, M L; Tormo, J; Selgas, M D; Casas, C

    1994-09-01

    A total of 80 food samples were purchased from local retail consumer shops and examined for the presence of motile Aeromonas spp. Of the food categories tested, poultry had the highest incidence, with 100% positive. This was followed by lamb samples, with 60% positive. Raw milk and cheese samples had very low incidence (20%). No motile Aeromonas spp. were found in pre-prepared salads. Shellfish, fish, pork and beef samples had incidences of 40%. Most of the strains isolated were Aeromonas hydrophila, and for most of the food categories, no Aeromonas caviae isolates were obtained. PMID:7873101

  5. Marker exchange mutagenesis of the aerolysin determinant in Aeromonas hydrophila demonstrates the role of aerolysin in A. hydrophila-associated systemic infections.

    PubMed Central

    Chakraborty, T; Huhle, B; Hof, H; Bergbauer, H; Goebel, W

    1987-01-01

    We report here on the isolation of isogenic strains of Aeromonas hydrophila AB3 deleted for a segment of the aerolysin gene. All aer mutants obtained lacked the 49-kilodalton aerolysin gene product and were neither hemolytic for blood erythrocytes nor cytotoxic for Chinese hamster ovary tissue culture cells. One such mutant, AB3-5, was used in a mouse toxicity model to evaluate the role of aerolysin in the pathogenesis of A. hydrophila infections. The strain had a 50% lethal dose (LD50) of greater than 10(9) as compared with the parental strain which had an LD50 of 5 X 10(7). Reintegration of the deleted segment into AB3-5 resulted in an LD50 of 6 X 10(7) cells for this revertant. Furthermore, all mice injected with a sublethal dose of the parental strains developed necrotic lesions; this was never obtained with the aerolysin-deficient strain AB3-5. More importantly, specific neutralizing antibody to aerolysin was detected in mice surviving A. hydrophila infection, demonstrating that aerolysin is produced during the course of systemic A. hydrophila infections. Images PMID:3305370

  6. Lactobacillus acidophilus attenuates Aeromonas hydrophila induced cytotoxicity in catla thymus macrophages by modulating oxidative stress and inflammation.

    PubMed

    Patel, Bhakti; Kumar, Premranjan; Banerjee, Rajanya; Basu, Madhubanti; Pal, Arttatrana; Samanta, Mrinal; Das, Surajit

    2016-07-01

    The pathogenesis of Aeromonas hydrophila, a potent fish pathogen, is attributed to its ability to cause motile aeromonad septicaemia leading to apoptosis in a myriad of fish species, including freshwater carp Catla catla. However, the underlying mechanism of antagonistic activity of probiotics against A. hydrophila induced apoptosis is not elucidated due to lack of appropriate in-vitro models. This study reported that the exposure of catla thymus macrophages (CTM) to A. hydrophila markedly induced cellular injuries as evidenced by elevated levels of reactive oxygen species (ROS), reactive nitrogen species (RNS), increased apoptosis, DNA damage and decreased cellular viability. Flow cytometry analysis and Annexin-V/propidium iodide assay further confirmed increased ROS positive cells leading to cell death after infection. The quantitative real-time PCR analysis, also revealed upregulation of inducible nitric-oxide synthase (iNOS), pro-inflammatory cytokine (TNFα), cyclooxygenase2 (COX-2) and downregulation of anti-inflammatory cytokine (IL-10). Pretreatment of cells with probiotic, Lactobacillus acidophilus attenuated A. hydrophila induced apoptosis as evident from the decrease in the levels of ROS, RNS and DNA damage. Significant increase (P≤0.05) in expression of TNFα and IL-10 and decrease in iNOS and COX-2 was observed on probiotic stimulation. In-vivo study using catla fingerlings confirmed similar pattern of ROS, iNOS, NO production and cytokine expression in thymus. This study provides a comprehensive insight into the mechanistic basis of L. acidophilus induced macrophage mediated inflammatory response against A. hydrophila in CTM cells. Further, it speculates the possibility of using cost-effective in-vitro models for screening probiotic candidates of therapeutic potential in aquaculture industry. PMID:27262084

  7. In vitro and in vivo studies of the use of some medicinal herbals against the pathogen Aeromonas hydrophila in goldfish.

    PubMed

    Harikrishnan, Ramasamy; Balasundaram, Chellam

    2008-09-01

    Aeromonas hydrophila is a ubiquitous and opportunistic bacterial pathogen that produces ulcerative dermatitis under stress conditions and inflicts severe losses on global fisheries and fish culture. This study evaluates the antimicrobial potency of aqueous and ethanolic decoction (individual extract) and concoction (mixed extract) of three common medicinal herbs, turmeric Curcuma longa, Tulsi plant Ocimum sanctum, and neem Azadirachta indica, against the in vitro growth of A. hydrophila. Among the decoctions, A. indica exhibited the most potent antibacterial property (P < 0.05) against A. hydrophila. Among the concoctions, both the aqueous and ethanolic triherbal extracts mixed in the ratio of 1:1:1 had higher antibacterial activity (P < 0.05) than the other concoctions and decoctions. Goldfish Carassius auratus (10 +/- 2 g) were challenged with A. hydrophila intramuscularly in the caudal region with two separate doses (days 1 and 3) of 50 microL/fish (1.8 x 10(3) colony-forming units per milliliter). On days 9 (early) and 15 (late) of infection, fish were held in a net and dip treated for 5 min daily in a 1-L solution of 1% aqueous triherbal concoction. Red blood cell (RBC) count, hemoglobin, and hematocrit levels of the infected group were significantly higher (P < 0.05) than those of the control group. In the early treated group, all of the affected profile values returned to near normal, while the late-treated group registered a partial recovery, such as improved RBC count. The derived hematological values, such as mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration, of the early and late-treated groups also significantly declined (P < 0.05) but were restored to near normal (P > 0.05) only in the early treated group. The results suggest that dip treatment of A. hydrophila-infected goldfish in an aqueous triherbal concoction had a synergistic restorative effect on the hematological variables. PMID:18942593

  8. The cytotoxic effect of essential oils from Origanum vulgare L. and/or Rosmarinus officinalis L. on Aeromonas hydrophila.

    PubMed

    Azerêdo, Geíza Alves de; Stamford, Tânia Lúcia Montenegro; Figueiredo, Regina Celia Bressan Queiroz de; Souza, Evandro Leite de

    2012-04-01

    This study aimed to evaluate the antibacterial activities of the essential oils from Origanum vulgare L. (OV) and Rosmarinus officinalis L. (RO), both singly and in combination at sub-inhibitory concentrations (¼ MIC + ¼ MIC), against Aeromonas hydrophila and to investigate the possible mechanisms underlying these activities. Used singly (OV: 2.5 μL/mL; RO: 20 μL/mL) or in a mixture (OV: 0.625 μL/mL + RO: 5 μL/L), these essential oils led to a significant decrease (p<0.01) in bacterial viability after 24 h of exposure. A decrease in glucose consumption by A. hydrophila and release of cellular material were observed immediately after the addition of the essential oils, both singly and as a mixture, and continued for up to 6 h. Electron microscopy of cells exposed to the essential oils revealed severe changes in the plasma membrane, cytoplasmic appearance, and cell shape during the 6-h exposure period. OV and RO essential oils combined at sub-inhibitory concentrations could be rationally applied to inhibit the growth of A. hydrophila in food products, particularly minimally processed vegetables. PMID:22300224

  9. Detection of Aeromonas hydrophila in Liquid Media by Volatile Production Similarity Patterns, Using a FF-2A Electronic Nose

    PubMed Central

    Fujioka, Kouki; Arakawa, Eiji; Kita, Jun-ichi; Aoyama, Yoshihiro; Manome, Yoshinobu; Ikeda, Keiichi; Yamamoto, Kenji

    2013-01-01

    A technique for rapid detection of pathogenic microorganisms is essential for the diagnosis of associated infections and for food safety analysis. Aeromonas hydrophila is one such food contaminant. Several methods for rapid detection of this pathogen have been developed; these include multiplex polymerase chain reaction assays and the colony overlay procedure for peptidases. However, these conventional methods can only be used to detect the microorganisms at high accuracy after symptomatic onset of the disease. Therefore, in the future, simple pre-screening methods may be useful for preventing food poisoning and disease. In this paper, we present a novel system for the rapid detection of the microorganism A. hydrophila in cultured media (in <2 h), with the use of an electronic nose (FF-2A). With this electronic nose, we detected the changes of volatile patterns produced by A. hydrophila after 30 min culture. Our calculations revealed that the increased volatiles were similar to the odours of organic acids and esters. In future, distinctive volatile production patterns of microorganisms identified with the electronic nose may have the potential in microorganism detection. PMID:23296330

  10. Molecular analysis of type II topoisomerases of Aeromonas hydrophila isolated from fish and levofloxacin-induced resistant isolates in vitro.

    PubMed

    Hu, Ruixue; Du, Na; Chen, Nan; Lin, Li; Zhai, Yanhua; Gu, Zemao

    2016-05-01

    The mechanisms of resistance to levofloxacin for Aeromonas hydrophila isolated from diseased fish and selected in vitro were examined in this study. Levofloxacin-resistant mutants were obtained by selection of A. hydrophila in vitro. The quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes were sequenced in Lev(R) strains and reverse mutation strains. All Lev(R) strains carried a point mutation at codon 83 (Ser → Ile), and one strain (25 %) harbored a mutation at position 92 (Leu → Met) in the GyrA-QRDR. After being transferred in a levofloxacin-free medium, one strain of the mutants was successfully reversed and the reversion was related with mutations of GyrA-QRDR at positions 81 (Gly → Asp) and 83 (Ile → Ser). No amino acid alteration was found in the ParC-QRDR. In addition, the minimum inhibitory concentration (MIC) of levofloxacin for the mutants was lower in the presence of reserpine, and all mutants were also resistant to some of the other quinolones. It was found that the mechanism of levofloxacin resistance of A. hydrophila selected in vitro was related to gyrA of type II topoisomerase, and an efflux mechanism was involved in the resistance as well. PMID:26503714

  11. Antagonistic Activity of Cellular Components of Potential Probiotic Bacteria, Isolated from the Gut of Labeo rohita, Against Aeromonas hydrophila.

    PubMed

    Giri, Sib Sankar; Sukumaran, V; Sen, Shib Sankar; Vinumonia, J; Banu, B Nazeema; Jena, Prasant Kumar

    2011-12-01

    The objective of this study was to characterise the antagonistic activity of cellular components of potential probiotic bacteria isolated from the gut of healthy rohu (Labeo rohita), a tropical freshwater fish, against the fish pathogen, Aeromonas hydrophila. Three potential probiotic strains (referred to as R1, R2, and R5) were screened using a well diffusion, and their antagonistic activity against A. hydrophila was determined. Biochemical tests and 16S rRNA gene analysis confirmed that R1, R2, and R5 were Lactobacillus plantarum VSG3, Pseudomonas aeruginosa VSG2, and Bacillus subtilis VSG1, respectively. Four different fractions of cellular components (i.e. the whole-cell product, heat-killed whole-cell product [HKWCP], intracellular product [ICP], and extracellular product) of these selected strains were effective in an in vitro sensitivity test against 6 A. hydrophila strains. Among the cellular components, the ICP of R1, HKWCP of R2, and ICP of R5 exhibited the strongest antagonistic activities, as evidenced by their inhibition zones. The antimicrobial compounds from these selected cellular components were partially purified by thin-layer and high-performance liquid chromatography, and their properties were analysed. The ranges of pH stability of the purified compounds were wide (3.0-10.0), and compounds were thermally stable up to 90 °C. Considering these results, isolated probiotic strains may find potential applications in the prevention and treatment of aquatic aeromonosis. PMID:26781682

  12. Aeromonas hydrophila as a causative organism in peritoneal dialysis-related peritonitis: case report and review of the literature.

    PubMed

    Liakopoulos, V; Arampatzis, S; Kourti, P; Tsolkas, T; Zarogiannis, S; Eleftheriadis, T; Giannopoulou, M; Stefanidis, I

    2011-02-01

    Most episodes of peritoneal dialysis (PD)-related peritonitis could be attributed to a single organism, but in almost 10% of peritonitis episodes multiple organisms are identified. Polymicrobial peritonitis is often related to intra-abdominal pathology, and the prognosis may be poor. Aeromonas spp. have rarely been identified as the causative pathogen in PD-related peritonitis, and a very small number of cases has been reported in the literature. These rod-shaped, gram-negative microorganisms have been isolated from wastewater drainage systems, food, vegetables, and soil. Herein we report a case of polymicrobial peritonitis in a continuous ambulatory peritoneal dialysis (CAPD) patient with systemic lupus erythematosus (SLE), due to a combination of Streptococcus viridans and Aeromonas hydrophila infection. The patient was involved in gardening and was not compliant with her technique protocol. She did not wear a mask and omitted thorough hand washing. The patient was treated with i.p. vancomycin and ceftazidime and peritonitis was resolved. The patient's technique was reassessed, and she was retrained by our PD nurses. PMID:21269597

  13. Immune effects of the vaccine of live attenuated Aeromonas hydrophila screened by rifampicin on common carp (Cyprinus carpio L).

    PubMed

    Jiang, Xinyu; Zhang, Chao; Zhao, Yanjing; Kong, Xianghui; Pei, Chao; Li, Li; Nie, Guoxing; Li, Xuejun

    2016-06-01

    Aeromonas hydrophila, as a strong Gram-negative bacterium, can infect a wide range of freshwater fish, including common carp Cyprinus carpio, and cause the huge economic loss. To create the effective vaccine is the best way to control the outbreak of the disease caused by A. hydrophila. In this study, a live attenuated A. hydrophila strain, XX1LA, was screened from the pathogenic A. hydrophila strain XX1 cultured on medium containing the antibiotic rifampicin, which was used as a live attenuated vaccine candidate. The immune protection of XX1LA against the pathogen A. hydrophila in common carp was evaluated by the relative percent survival (RPS), the specific IgM antibody titers, serum lysozyme activity and the expression profiles of multiple immune-related genes at the different time points following immunization. The results showed that the variable up-regulations of the immune-related genes, such as the pro-inflammatory cytokine IL-1β, the chemokine IL-10 and IgM, were observed in spleen and liver of common carp injected in the vaccines with the formalin-killed A. hydrophila (FKA) and the live attenuated XX1LA. Specific antibody to A. hydrophila was found to gradually increase during 28 days post-vaccination (dpv), and the RPS (83.7%) in fish vaccinated with XX1LA, was significant higher than that (37.2%) in fish vaccinated with FKA (P<0.05) on Day 28 after challenged by pathogen. It was demonstrated that the remarkable immune protection presented in the group vaccinated with XX1LA. During the late stage of 4-week immunization phase, compared with FKA and the control, specific IgM antibody titers significantly increased (P<0.05) in the XX1LA group. The activity of the lysozyme in serum indicated no significant change among three groups. In summary, the live attenuated bacterial vaccine XX1LA, screened in this study, indicates the better protect effect on common carp against A. hydrophila, which can be applied in aquaculture of common carp to prevent from the

  14. Acanthamoeba castellanii of the T4 genotype is a potential environmental host for Enterobacter aerogenes and Aeromonas hydrophila

    PubMed Central

    2013-01-01

    Background Acanthamoeba can interact with a wide range of microorganisms such as viruses, algae, yeasts, protists and bacteria including Legionella pneumophila, Pseudomonas aeruginosa, Vibrio cholerae, Helicobacter pylori, Listeria monocytogenes, Mycobacterium spp., and Escherichia coli. In this capacity, Acanthamoeba has been suggested as a vector in the transmission of bacterial pathogens to the susceptible hosts. Methods Here, we used a keratitis isolate of A. castellanii of the T4 genotype and studied its interactions with two bacterial genera which have not been tested before, Enterobacter aerogenes, and Aeromonas hydrophila, as well as E. coli. Assays were performed to determine bacterial association with and invasion of A. castellanii. Additionally, bacterial survival intracellular of A. castellanii trophozoites as well as cysts was determined. Results All three bacterial isolates tested, associated, invaded, and survived inside A. castellanii trophozoites as well as A. castellanii cysts. However, E. aerogenes and E. coli exhibited significantly reduced association with and invasion of A. castellanii as compared with A. hydrophila (P < 0.01 using paired T-test, one tail distribution). In the long term survival assays, all three bacterial isolates tested remained viable inside A. castellanii trophozoites, while amoeba remained intact; however A. hydrophila exhibited higher survival inside amoebae (14.54 ± 3.3 bacteria:amoeba ratio) compared with E. aerogenes (3.96 ± 0.7 bacteria:amoeba ratio) and E. coli (5.85 ± 1.1 bacteria:amoeba ratio). A. hydrophila, E. coli, and E. aerogenes remained viable during the encystment process and exhibited higher levels of recovery from mature cysts (14.13 ± 0.89 A. hydrophila:amoeba ratio, 10.13 ± 1.17 E. aerogenes:amoeba ratio, and 11.95 ± 0.7 E. coli:amoeba ratio). Conclusions A. hydrophila and E. aerogenes also joined the ranks of other bacteria that could benefit from A. castellanii

  15. Farm size, seining practices, and salt use: risk factors for Aeromonas hydrophila outbreaks in farm-raised catfish, Alabama, USA.

    PubMed

    Bebak, Julie; Wagner, Bruce; Burnes, Brian; Hanson, Terry

    2015-01-01

    In freshwater aquaculture systems, Aeromonas hydrophila is usually considered to be an opportunistic pathogen most often associated with secondary bacterial infections. Since 2009, the U.S. catfish industry, especially in West Alabama, has been affected by mortality from a strain of A. hydrophila that has been acting as a primary pathogen. Tens of millions of pounds of catfish production have been lost as a consequence of this disease. This study used data from two whole-population farmer surveys to examine farm-level risk factors for two A. hydrophila outbreaks in foodsize Alabama catfish, one in 2009 (surveyed in 2010), and one in 2011 (surveyed in 2012). The response to the 2010 survey was 85% and the response to the 2012 survey was 82%. Univariate analyses were used to examine biologically plausible variables (farm size, pond stocking density, seine exposure, use of salt (NaCl) in ponds), and used categorical disease outcome and dependent variables. Farm size was included in bivariate analyses with the other variables, because it was a potential confounding variable. For both study years, the odds of an A. hydrophila outbreak were significantly greater for farms larger than the mean size (2009: mean=132 acres (53.4 hectares), odds ratio (OR)=8.2; 95% confidence interval (CI)=3.3-20.6, p<0.001; 2011: mean=116 acres (46.9 hectares), OR=5.3, CI=1.7-17.0, p=0.009). Compared with 42% of control farms, every case farm was seined by a commercial or processing plant seining crew in 2009. The bivariate analysis of the 2011 variable "average number of times each pond was seined per year" indicated that regardless of farm size, farms with ponds that were seined more than twice per year had a significantly greater odds of an A. hydrophila outbreak (OR=4.1, CI=1.2-14.4, p=0.02). For 2009, the results of the bivariate analyses of chloride concentrations indicated that farms that had chloride concentrations >135 ppm had a significantly lower odds of experiencing A. hydrophila

  16. Effects of dietary Lactobacillus plantarum and AHL lactonase on the control of Aeromonas hydrophila infection in tilapia.

    PubMed

    Liu, Wenshu; Ran, Chao; Liu, Zhi; Gao, Qian; Xu, Shude; Ringø, Einar; Myklebust, Reidar; Gu, Zemao; Zhou, Zhigang

    2016-08-01

    This study addressed the effects of dietary Lactobacillus plantarum or/and N-acylated homoserine lactonase (AHL lactonase) on controlling Aeromonas  hydrophila infection in juvenile hybrid tilapia (Oreochromis niloticus♀ × O. aureus ♂). Fish were fed Lb. plantarum subsp. plantarum strain JCM1149 (10(8)  CFU/g feed) or/and AHL lactonase AIO6 (4 U/g) and were exposed to a chronic challenge of A. hydrophila NJ-1 (10(5)  cells/mL) for 14 days. Intestinal (foregut) alkaline phosphatase (IAP) activities were evaluated 1 day post challenge to reflect the resistance of fish against A. hydrophila infection. Parallel groups of fish with the same dietary assignments while unchallenged were also included to investigate the effect of dietary Lb. plantarum or/and AIO6 supplementation on gut health of tilapia. The results showed that IAP activity was significantly lower in fish fed with diets supplemented with Lb. plantarum JCM1149 or the combination of Lb. plantarum JCM1149 and AIO6, indicating enhanced resistance against A. hydrophila. Light microscopy and transmission electron microscopy images of foregut revealed damage caused by A. hydrophila NJ-1, but dietary Lb. plantarumJCM1149 or/and AIO6 significantly alleviated the damages. Compared to the fish immersed in A. hydrophila NJ-1, dietary Lb. plantarum JCM1149 or AIO6 could maintain the microvilli length in the foregut of tilapia. However, among the unchallenged groups of fish, the microvilli length in the foregut of tilapia fed AIO6 (singly or combination) and the microvilli density of tilapia fed AIO6 (singly) were significantly lower than those of the control, though the microvilli density in the combination treatment was significantly improved. Additionally, the dietary Lb. plantarum JCM1149 could down-regulate the expression of stress-related gene in the gut after the acute phase. In conclusion, the dietary Lb. plantarum JCM1149 is recommended to control the A. hydrophila infection in

  17. A 425 T>C polymorphism in complement C7 association with resistance to Aeromonas hydrophila in grass carp.

    PubMed

    Shen, Y B; Zhang, J B; Fu, J J; Xu, X Y; Li, J L; Wang, R Q; Xuan, Y F

    2016-01-01

    Aeromonas hydrophila, a widespread bacterium in the aquatic environment, causes hemorrhagic septicemia in fish. In the last decade, the disease has caused mass mortalities and tremendous economic loss in cultured fish. The complement component C7 is a terminal component of complement that interacts in a sequence of polymerization reactions with other terminal complement components to form a membrane attack complex. The formation of the membrane attack complex creates a pore in the membranes of certain pathogen that can lead to their death. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the C7 gene and to assess their association with A. hydrophila resistance in grass carp. A resource population consisting of 186 susceptible and 191 resistant grass carp was constructed. We sequenced a total of 7826 bp of the C7 gene and identified 6 SNPs that were genotyped in the resource population. The SNP -1575 A>C was positioned in the promoter region of the gene. The SNP 425 C>T identified in the coding exon was a synonymous substitution in the fourth exon. Statistical analysis showed that SNP 425 C>T was associated with the incidence of hemorrhagic septicemia. The SNPs -1575 A>C, -688 T>C, and -266 A>C were highly linked together (r(2) > 0.85). No haplotypes generated with these 3 SNPs were associated with resistance to A. hydrophila in grass carp. These findings suggest that the 425 C>T polymorphism in C7 gene may be a significant molecular marker for resistance to A. hydrophila in grass carp. PMID:27050969

  18. Polar Glycosylated and Lateral Non-Glycosylated Flagella from Aeromonas hydrophila Strain AH-1 (Serotype O11).

    PubMed

    Fulton, Kelly M; Mendoza-Barberá, Elena; Twine, Susan M; Tomás, Juan M; Merino, Susana

    2015-01-01

    Polar and but not lateral flagellin proteins from Aeromonas hydrophila strain AH-1 (serotype O11) were found to be glycosylated. Top-down mass spectrometry studies of purified polar flagellins suggested the presence of a 403 Da glycan of mass. Bottom-up mass spectrometry studies showed the polar flagellin peptides to be modified with 403 Da glycans in O-linkage. The MS fragmentation pattern of this putative glycan was similar to that of pseudaminic acid derivative. Mutants lacking the biosynthesis of pseudaminic acid (pseB and pseI homologues) were unable to produce polar flagella but no changes were observed in lateral flagella by post-transcriptional regulation of the flagellin. Complementation was achieved by reintroduction of the wild-type pseB and pseI. We compared two pathogenic features (adhesion to eukaryotic cells and biofilm production) between the wild-type strain and two kinds of mutants: mutants lacking polar flagella glycosylation and lacking the O11-antigen lipopolysaccharide (LPS) but with unaltered polar flagella glycosylation. Results suggest that polar flagella glycosylation is extremely important for A. hydrophila AH-1 adhesion to Hep-2 cells and biofilm formation. In addition, we show the importance of the polar flagella glycosylation for immune stimulation of IL-8 production via toll-"like" receptor 5 (TLR5). PMID:26633358

  19. Pharmacokinetic/pharmacodynamic relationship of marbofloxacin against Aeromonas hydrophila in Chinese soft-shelled turtles (Trionyx sinensis).

    PubMed

    Shan, Q; Zheng, G; Liu, S; Bai, Y; Li, L; Yin, Y; Ma, L; Zhu, X

    2015-12-01

    The single-dose disposition kinetics of the antibiotic marbofloxacin were determined in Chinese soft-shelled turtles (n = 10) after oral and intramuscular (i.m.) dose of 10 mg/kg bodyweight. The in vitro and ex vivo activities of marbofloxacin in serum against a pathogenic strain of Aeromonas hydrophila were determined. A concentration-dependent antimicrobial activity of marbofloxacin was confirmed for levels lower than 4 × MIC. For in vivo PK data, values of AUC: minimum inhibitory concentration (MIC) ratio for serum were 1166.6 and 782.4 h, respectively, after i.m. and oral dosing of marbofloxacin against a pathogenic strain of A. hydrophila (MIC = 0.05 μg/mL). The ex vivo growth inhibition data after oral dosing were fitted to the inhibitory sigmoid Emax equation to provide the values of AUC/MIC required to produce bacteriostasis, bactericidal activity and elimination of bacteria. The respective values were 23.79, 36.35 and 126.46 h. It is proposed that these findings might be used with MIC50 or MIC90 data to provide a rational approach to the design of dosage schedules, which optimize efficacy in respect of bacteriological as well as clinical cures. PMID:25694049

  20. Effect of Lactobacillus plantarum C014 on Innate Immune Response and Disease Resistance against Aeromonas hydrophila in Hybrid Catfish

    PubMed Central

    Butprom, Sureerat; Phumkhachorn, Parichat; Rattanachaikunsopon, Pongsak

    2013-01-01

    A bacterial strain isolated from intestines of hybrid catfish (Clarias gariepinus Male × Clarias macrocephalus Female) exhibited an in vitro inhibitory effect on a fish pathogen, Aeromonas hydrophila TISTR 1321. By using the 16S rDNA sequence analysis, it was identified as Lactobacillus plantarum C014. To examine whether L. plantarum C014 had potential for use as an immunostimulant and biocontrol agent in hybrid catfish, the fish diet supplemented with L. plantarum C014 (107 CFU/g diet) was prepared and used for the in vivo investigation of its effect on innate immune response and disease resistance of hybrid catfish. Two innate immune response parameters, phagocytic activity of blood leukocytes and plasma lysozyme activity, were significantly enhanced in the treated fish after 45 days of feeding. Feeding the fish with the L. plantarum C014 supplemented diet for 45 days before challenging them with A. hydrophila at the dose of LD50 could reduce the mortality rate of the fish from 50% (in control group) to 0% (in treated group). Based on its origin and beneficial effect on innate immune response and disease resistance, L. plantarum C014 may be a potential candidate for use as a natural and safe immunostimulant and biocontrol agent in hybrid catfish. PMID:24453842

  1. Polar Glycosylated and Lateral Non-Glycosylated Flagella from Aeromonas hydrophila Strain AH-1 (Serotype O11)

    PubMed Central

    Fulton, Kelly M.; Mendoza-Barberá, Elena; Twine, Susan M.; Tomás, Juan M.; Merino, Susana

    2015-01-01

    Polar and but not lateral flagellin proteins from Aeromonas hydrophila strain AH-1 (serotype O11) were found to be glycosylated. Top-down mass spectrometry studies of purified polar flagellins suggested the presence of a 403 Da glycan of mass. Bottom-up mass spectrometry studies showed the polar flagellin peptides to be modified with 403 Da glycans in O-linkage. The MS fragmentation pattern of this putative glycan was similar to that of pseudaminic acid derivative. Mutants lacking the biosynthesis of pseudaminic acid (pseB and pseI homologues) were unable to produce polar flagella but no changes were observed in lateral flagella by post-transcriptional regulation of the flagellin. Complementation was achieved by reintroduction of the wild-type pseB and pseI. We compared two pathogenic features (adhesion to eukaryotic cells and biofilm production) between the wild-type strain and two kinds of mutants: mutants lacking polar flagella glycosylation and lacking the O11-antigen lipopolysaccharide (LPS) but with unaltered polar flagella glycosylation. Results suggest that polar flagella glycosylation is extremely important for A. hydrophila AH-1 adhesion to Hep-2 cells and biofilm formation. In addition, we show the importance of the polar flagella glycosylation for immune stimulation of IL-8 production via toll-“like” receptor 5 (TLR5). PMID:26633358

  2. Multiplex-PCR for simultaneous detection of 3 bacterial fish pathogens, Flavobacterium columnare, Edwardsiella ictaluri, and Aeromonas hydrophila.

    PubMed

    Panangala, Victor S; Shoemaker, Craig A; Van Santen, Vicky L; Dybvig, Kevin; Klesius, Phillip H

    2007-03-13

    A multiplex PCR (m-PCR) method was developed for simultaneous detection of 3 important fish pathogens in warm water aquaculture. The m-PCR to amplify target DNA fragments from Flavobacterium columnare (504 bp), Edwardsiella ictaluri (407 bp) and Aeromonas hydrophila (209 bp) was optimized by adjustment of reaction buffers and a touchdown protocol. The lower detection limit for each of the 3 bacteria was 20 pg of nucleic acid template from each bacteria per m-PCR reaction mixture. The sensitivity threshold for detection of the 3 bacteria in tissues ranged between 3.4 x 10(2) and 2.5 x 10(5) cells g(-1) of tissue (channel catfish Ictalurus punctatus Rafinesque). The diagnostic sensitivity and specificity of the m-PCR was evaluated with 10 representative isolates of each of the 3 bacteria and 11 other Gram-negative and 2 Gram-positive bacteria that are taxonomically related or ubiquitous in the aquatic environment. Except for a single species (A. salmonicida subsp. salmonicida), each set of primers specifically amplified the target DNA of the cognate species of bacteria. m-PCR was compared with bacteriological culture for identification of bacteria in experimentally infected fish. The m-PCR appears promising for the rapid, sensitive and simultaneous detection of Flavobacterium columnare, E. ictaluri and A. hydrophila in infected fish compared to the time-consuming traditional bacteriological culture techniques. PMID:17465305

  3. Cross-talk among flesh-eating Aeromonas hydrophila strains in mixed infection leading to necrotizing fasciitis.

    PubMed

    Ponnusamy, Duraisamy; Kozlova, Elena V; Sha, Jian; Erova, Tatiana E; Azar, Sasha R; Fitts, Eric C; Kirtley, Michelle L; Tiner, Bethany L; Andersson, Jourdan A; Grim, Christopher J; Isom, Richard P; Hasan, Nur A; Colwell, Rita R; Chopra, Ashok K

    2016-01-19

    Necrotizing fasciitis (NF) caused by flesh-eating bacteria is associated with high case fatality. In an earlier study, we reported infection of an immunocompetent individual with multiple strains of Aeromonas hydrophila (NF1-NF4), the latter three constituted a clonal group whereas NF1 was phylogenetically distinct. To understand the complex interactions of these strains in NF pathophysiology, a mouse model was used, whereby either single or mixed A. hydrophila strains were injected intramuscularly. NF2, which harbors exotoxin A (exoA) gene, was highly virulent when injected alone, but its virulence was attenuated in the presence of NF1 (exoA-minus). NF1 alone, although not lethal to animals, became highly virulent when combined with NF2, its virulence augmented by cis-exoA expression when injected alone in mice. Based on metagenomics and microbiological analyses, it was found that, in mixed infection, NF1 selectively disseminated to mouse peripheral organs, whereas the other strains (NF2, NF3, and NF4) were confined to the injection site and eventually cleared. In vitro studies showed NF2 to be more effectively phagocytized and killed by macrophages than NF1. NF1 inhibited growth of NF2 on solid media, but ExoA of NF2 augmented virulence of NF1 and the presence of NF1 facilitated clearance of NF2 from animals either by enhanced priming of host immune system or direct killing via a contact-dependent mechanism. PMID:26733683

  4. Species identification of Aeromonas strains based on carbon substrate oxidation profiles.

    PubMed Central

    Carnahan, A M; Joseph, S W; Janda, J M

    1989-01-01

    Twenty clinical strains each of Aeromonas hydrophila, Aeromonas caviae, and Aeromonas sobria were evaluated for their abilities to oxidize one or more of 95 carbon sources on a GN Microplate (BIOLOG, Hayward, Calif.). Nine substrates yielded good, discriminatory values for the three species tested. The panel appears to be useful for the species identification of Aeromonas isolates originating from human material. PMID:2778077

  5. Protective effects of the prebiotic on the immunological indicators of rainbow trout (Oncorhynchus mykiss) infected with Aeromonas hydrophila.

    PubMed

    Yarahmadi, Peyman; Ghafari Farsani, Hamed; Khazaei, Amin; Khodadadi, Mohammad; Rashidiyan, Ghasem; Jalali, M Ali

    2016-07-01

    The aim of this study was to investigate the protective effects of dietary administration of commercial prebiotic, Immunogen, on immunological indicators, enzymatic responses and stress tolerance in juvenile (81.65 ± 1.49) rainbow trout (Oncorhynchus mykiss) following Aeromonas hydrophila infection. The first group of fish was fed with the diet containing 2 g kg(-1) Immunogen whilst the control group received the diet free of Immunogen. There were three replicates per group. After 6 weeks feeding, the control group were divided into two treatments injected with saline buffer (control), and 1.5 × 10(8) CFU A. hydrophila respectively. The fish fed with the Immunogen supplemented diet were also injected with 1.5 × 10(8) CFU A. hydrophila. Our results revealed that dietary Immunogen increased the level of white blood cell (WBC) and percentage of lymphocyte (P < 0.05), however, the level of red blood cell (RBC), Hematocrit (Hct), hemoglobin (Hb) and percent of monocyte decreased in Untreated-Challenged group but unaffected in the group fed with Immunogen (P < 0.05). The level of lysozyme, alternative complement, antiprotease activity, total protein, albumin and globulin decreased in Untreated- Challenged group compared to control group. However, there was an increase in the level of lysozyme, alternative complement, antiprotease activity, bactericidal activity, in the Treated- Challenged group compared to other groups (P < 0.05). Serum alkali phosphatase (ALT) and aspartate aminotransferase, significantly increased fallowing challenge with A. hydrophila but in the Treated-Challenged group, there was no significant difference compared to the control group (P < 0.05). Lactate dehydrogenase (LDH) level was not different between groups (P > 0.05). Serum cortisol and glucose levels were higher in the challenge group, but these levels were lower in fish under challenge that were fed Immunogen-supplemented diet in contrast to the group fed control diet

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

    EPA Science Inventory

    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...

  7. Transcriptome Analysis of the Innate Immunity-Related Complement System in Spleen Tissue of Ctenopharyngodon idella Infected with Aeromonas hydrophila

    PubMed Central

    Dang, Yunfei; Xu, Xiaoyan; Shen, Yubang; Hu, Moyan; Zhang, Meng; Li, Lisen; Lv, Liqun; Li, Jiale

    2016-01-01

    The grass carp (Ctenopharyngodon idella) is an important commercial farmed herbivorous fish species in China, but is susceptible to Aeromonas hydrophila infections. In the present study, we performed de novo RNA-Seq sequencing of spleen tissue from specimens of a disease-resistant family, which were given intra-peritoneal injections containing PBS with or without a dose of A. hydrophila. The fish were sampled from the control group at 0 h, and from the experimental group at 4, 8, 12, 24, 48 and 72 h. 122.18 million clean reads were obtained from the normalized cDNA libraries; these were assembled into 425,260 contigs and then 191,795 transcripts. Of those, 52,668 transcripts were annotated with the NCBI Nr database, and 41,347 of the annotated transcripts were assigned into 90 functional groups. 20,569 unigenes were classified into six main categories, including 38 secondary KEGG pathways. 2,992 unigenes were used in the analysis of differentially expressed genes (DEGs). 89 of the putative DEGs were related to the immune system and 41 of them were involved in the complement and coagulation cascades pathway. This study provides insights into the complement and complement-related pathways involved in innate immunity, through expression profile analysis of the genomic resources in C. idella. We conclude that complement and complement-related genes play important roles during defense against A. hydrophila infection. The immune response is activated at 4 h after the bacterial injections, indicating that the complement pathways are activated at the early stage of bacterial infection. The study has improved our understanding of the immune response mechanisms in C. idella to bacterial pathogens. PMID:27383749

  8. Genome wide identification of scavenger receptors class A in common carp (Cyprinus carpio) and their expression following Aeromonas hydrophila infection.

    PubMed

    Feng, Shuaisheng; Jiang, Yanliang; Zhang, Songhao; Dong, Chuanju; Jiang, Likun; Peng, Wenzhu; Mu, Xidong; Sun, Xiaowen; Xu, Peng

    2016-07-01

    Scavenger receptors class A (SCARAs) is a subgroup of diverse families of pattern recognition receptors that bind a range of ligands, and play important roles in innate immune processes through pathogens detection, adhesion, endocytosis, and phagocytosis. However, most studies of SCARAs have focused on mammals, and much less is known of SCARAs in fish species. In this study, we identified 7 SCARAs across the common carp genome, which were classified into four subclasses according to comparative genomic analysis including sequence similarities analysis, gene structure and functional domain prediction. Further phylogenetic and syntenic analysis supported their annotation and orthologies. Through examining gene copy number of SCARA genes across several vertebrates, SCARA2, SCARA3 and SCARA4 were found have undergone gene duplication. The expression patterns of SCARAs in common carp were examined during early developmental stages, in healthy tissues, and after Aeromonas hydrophila infection. Most SCARA genes were ubiquitously expressed during common carp early developmental stages, and presented diverse patterns in various healthy tissues, with relatively high expression levels in spleen, liver, intestine, gill and brain, indicating their critical roles likely in maintaining homeostasis and host immune response activities. After A. hydrophila infection, most SCARA genes were up-regulated at 4 h post infection in mucosal tissue intestine, while generally up-regulated at 12 h post infection in spleen, suggesting a tissue-specific pattern of regulation. Taken together, all these results suggested that SCARA genes played important roles in host immune response to A. hydrophila infection in common carp, and provided important genomic resources for future studies on fish disease management. PMID:27041666

  9. Aeromonas hydrophila OmpW PLGA Nanoparticle Oral Vaccine Shows a Dose-Dependent Protective Immunity in Rohu (Labeo rohita).

    PubMed

    Dubey, Saurabh; Avadhani, Kiran; Mutalik, Srinivas; Sivadasan, Sangeetha Madambithara; Maiti, Biswajit; Paul, Joydeb; Girisha, Shivani Kallappa; Venugopal, Moleyur Nagarajappa; Mutoloki, Stephen; Evensen, Øystein; Karunasagar, Indrani; Munang'andu, Hetron Mweemba

    2016-01-01

    Aeromonas hydrophila is a Gram-negative bacterium that causes high mortality in different fish species and at different growth stages. Although vaccination has significantly contributed to the decline of disease outbreaks in aquaculture, the use of oral vaccines has lagged behind the injectable vaccines due to lack of proven efficacy, that being from primary immunization or by use of boost protocols. In this study, the outer membrane protein W (OmpW) of A. hydrophila was cloned, purified, and encapsulated in poly d,l-lactide-co-glycolic acid (PLGA) nanoparticles (NPs) for oral vaccination of rohu (Labeo rohita Hamilton). The physical properties of PLGA NPs encapsulating the recombinant OmpW (rOmpW) was characterized as having a diameter of 370-375 nm, encapsulation efficiency of 53% and -19.3 mV zeta potential. In vitro release of rOmpW was estimated at 34% within 48 h of incubation in phosphate-buffered saline. To evaluate the efficacy of the NP-rOmpW oral vaccine, two antigen doses were orally administered in rohu with a high antigen (HiAg) dose that had twice the amount of antigens compared to the low antigen (LoAg) dose. Antibody levels obtained after vaccination showed an antigen dose dependency in which fish from the HiAg group had higher antibody levels than those from the LoAg group. The antibody levels corresponded with post challenge survival proportions (PCSPs) and relative percent survival (RPS) in which the HiAg group had a higher PCSP and RPS than the LoAg group. Likewise, the ability to inhibit A. hydrophila growth on trypticase soy agar (TSA) by sera obtained from the HiAg group was higher than that from the LoAg group. Overall, data presented here shows that OmpW orally administered using PLGA NPs is protective against A. hydrophila infection with the level of protective immunity induced by oral vaccination being antigen dose-dependent. Future studies should seek to optimize the antigen dose and duration of oral immunization in rohu in order to

  10. A linkage map of transcribed single nucleotide polymorphisms in rohu (Labeo rohita) and QTL associated with resistance to Aeromonas hydrophila

    PubMed Central

    2014-01-01

    Background Production of carp dominates world aquaculture. More than 1.1 million tonnes of rohu carp, Labeo rohita (Hamilton), were produced in 2010. Aeromonas hydrophila is a bacterial pathogen causing aeromoniasis in rohu, and is a major problem for carp production worldwide. There is a need to better understand the genetic mechanisms affecting resistance to this disease, and to develop tools that can be used with selective breeding to improve resistance. Here we use a 6 K SNP array to genotype 21 full-sibling families of L. rohita that were experimentally challenged intra-peritoneally with a virulent strain of A. hydrophila to scan the genome for quantitative trait loci associated with disease resistance. Results In all, 3193 SNPs were found to be informative and were used to create a linkage map and to scan for QTL affecting resistance to A. hydrophila. The linkage map consisted of 25 linkage groups, corresponding to the number of haploid chromosomes in L. rohita. Male and female linkage maps were similar in terms of order, coverage (1384 and 1393 cM, respectively) and average interval distances (1.32 and 1.35 cM, respectively). Forty-one percent of the SNPs were annotated with gene identity using BLAST (cut off E-score of 0.001). Twenty-one SNPs mapping to ten linkage groups showed significant associations with the traits hours of survival and dead or alive (P <0.05 after Bonferroni correction). Of the SNPs showing significant or suggestive associations with the traits, several were homologous to genes of known immune function or were in close linkage to such genes. Genes of interest included heat shock proteins (70, 60, 105 and “small heat shock proteins”), mucin (5b precursor and 2), lectin (receptor and CD22), tributyltin-binding protein, major histocompatibility loci (I and II), complement protein component c7-1, perforin 1, ubiquitin (ligase, factor e4b isoform 2 and conjugation enzyme e2 c), proteasome subunit, T-cell antigen receptor and

  11. Aeromonas hydrophila OmpW PLGA Nanoparticle Oral Vaccine Shows a Dose-Dependent Protective Immunity in Rohu (Labeo rohita)

    PubMed Central

    Dubey, Saurabh; Avadhani, Kiran; Mutalik, Srinivas; Sivadasan, Sangeetha Madambithara; Maiti, Biswajit; Paul, Joydeb; Girisha, Shivani Kallappa; Venugopal, Moleyur Nagarajappa; Mutoloki, Stephen; Evensen, Øystein; Karunasagar, Indrani; Munang’andu, Hetron Mweemba

    2016-01-01

    Aeromonas hydrophila is a Gram-negative bacterium that causes high mortality in different fish species and at different growth stages. Although vaccination has significantly contributed to the decline of disease outbreaks in aquaculture, the use of oral vaccines has lagged behind the injectable vaccines due to lack of proven efficacy, that being from primary immunization or by use of boost protocols. In this study, the outer membrane protein W (OmpW) of A. hydrophila was cloned, purified, and encapsulated in poly d,l-lactide-co-glycolic acid (PLGA) nanoparticles (NPs) for oral vaccination of rohu (Labeo rohita Hamilton). The physical properties of PLGA NPs encapsulating the recombinant OmpW (rOmpW) was characterized as having a diameter of 370–375 nm, encapsulation efficiency of 53% and −19.3 mV zeta potential. In vitro release of rOmpW was estimated at 34% within 48 h of incubation in phosphate-buffered saline. To evaluate the efficacy of the NP-rOmpW oral vaccine, two antigen doses were orally administered in rohu with a high antigen (HiAg) dose that had twice the amount of antigens compared to the low antigen (LoAg) dose. Antibody levels obtained after vaccination showed an antigen dose dependency in which fish from the HiAg group had higher antibody levels than those from the LoAg group. The antibody levels corresponded with post challenge survival proportions (PCSPs) and relative percent survival (RPS) in which the HiAg group had a higher PCSP and RPS than the LoAg group. Likewise, the ability to inhibit A. hydrophila growth on trypticase soy agar (TSA) by sera obtained from the HiAg group was higher than that from the LoAg group. Overall, data presented here shows that OmpW orally administered using PLGA NPs is protective against A. hydrophila infection with the level of protective immunity induced by oral vaccination being antigen dose-dependent. Future studies should seek to optimize the antigen dose and duration of oral immunization in rohu in order to

  12. Molecular cloning and heterologous expression of laccase from Aeromonas hydrophila NIU01 in Escherichia coli with parameters optimization in production.

    PubMed

    Ng, I-Son; Zhang, Xia; Zhang, Yu; Lu, Yinghua

    2013-04-01

    Prior studies disclosed that Aeromonas hydrophila NIU01 was a biodecolorization and bioelectricity bacterium which was isolated from a cross-strait of Taiwan. However, enzymatic function, laccase, involved in this strain had never been reported. This first attempt is to explore its laccase activity, the molecular cloning and heterologous recombinant expression in Escherichia coli. A full-length novel gene of 1,647 bp, LacA, encoding of 549 amino acids was successfully cloned by polymerase chain reaction. The recombinant pET-15b(+)-NIU-LacA expression was compared in different E. coli strains. By applying Taguchi's L9 in culture optimization, the soluble laccase increased to 22.7 %, in which the conditions were obtained at 22 °C with initial shaking speed at 200 rpm, addition of lactose of 0.2 mM and CuSO4 of 0.5 mM to the medium, and shaking off while cell mass reached to OD(600nm) of 1.5. NIU-LacA was strongly inhibited by chloride ion. The optimal temperature was 60 °C and the optimum pH for ABTS (2,2'-azino-bis (3-ethylbenzthiazolinesulfonic acid) and 2,6-DMP (2,6-dimethoxyphenol) were pH 2.1 and pH 7.5 which enzymatic activity was 274.6 and 44.8 U/L, respectively. Further study in structural modeling of NIU-LacA showed the C terminal domain was the major variance in the three most closely A. hydrophila strains. PMID:23423657

  13. Immune responses to Aeromonas hydrophila infection in Schizothorax prenanti fed with oxidized konjac glucomannan and its acidolysis products.

    PubMed

    Zheng, Qiaoran; Wu, Yinglong; Xu, Huailiang; Wang, Hongjie; Tang, Haolan; Xia, Xiaojie; Feng, Jiao

    2016-02-01

    The objective of the present study was to determine the effect of dietary oxidized konjac glucomannan (OKGM) and its acidolysis products (L-OKGM) on the immune parameters and the gene expression profile of some inflammatory-related cytokines from Schizothorax prenanti during the early stages of injection with Aeromonas hydrophila. Fish were orally administered with seven different diets containing 0 g kg(-1) (control diet), 8.0, 16.0 and 32.0 g kg(-1) OKGM and L-OKGM diets for 60 days prior to injection. After 60 days, the control and the treated fish were intraperitoneally injected with 0.2 ml PBS or 2 × 10(7) cfu/ml bacteria per fish and sampled at time 6 h post-injection. The results showed that the serum lysozyme activity and complement C3 level of fish fed 8.0 g kg(-1) L-OKGM was significantly increased after bacterial infection. Moreover, the injection with A. hydrophila generally up-regulated the expression of all measured genes when compared to their corresponding controls. When compared with the control group, the expression of TLR22, TNF-α and IL-1β was significantly increased in fish fed OKGM and L-OKGM diet after bacterial injection. Furthermore, the L-OKGM diet showed higher activity to trigger the immune response against bacteria, especially the low dosage L-OKGM diet. The results suggested that both of OKGM and L-OKGM are promising feed additive for S. prenanti in aquaculture. PMID:26748343

  14. Common mechanistic features among metallo-beta-lactamases: a computational study of Aeromonas hydrophila CphA enzyme.

    PubMed

    Simona, Fabio; Magistrato, Alessandra; Dal Peraro, Matteo; Cavalli, Andrea; Vila, Alejandro J; Carloni, Paolo

    2009-10-01

    Metallo-beta-lactamases (MbetaLs) constitute an increasingly serious clinical threat by giving rise to beta-lactam antibiotic resistance. They accommodate in their catalytic pocket one or two zinc ions, which are responsible for the hydrolysis of beta-lactams. Recent x-ray studies on a member of the mono-zinc B2 MbetaLs, CphA from Aeromonas hydrophila, have paved the way to mechanistic studies of this important subclass, which is selective for carbapenems. Here we have used hybrid quantum mechanical/molecular mechanical methods to investigate the enzymatic hydrolysis by CphA of the antibiotic biapenem. Our calculations describe the entire reaction and point to a new mechanistic description, which is in agreement with the available experimental evidence. Within our proposal, the zinc ion properly orients the antibiotic while directly activating a second catalytic water molecule for the completion of the hydrolytic cycle. This mechanism provides an explanation for a variety of mutagenesis experiments and points to common functional facets across B2 and B1 MbetaLs. PMID:19671702

  15. Predictive modelling of growth and measurement of enzymatic synthesis and activity by a cocktail of selected Enterobacteriaceae and Aeromonas hydrophila.

    PubMed

    Braun, P; Sutherland, J P

    2005-11-25

    The possibility was examined of developing a predictive model that would predict food spoilage by combining microbial growth (increase in cellular number) with extracellular enzymatic activity of a cocktail of five strains of Enterobacteriaceae: Escherichia coli, Enterobacter agglomerans, Klebsiella oxytoca, Klebsiella pneumoniae and Proteus vulgaris and one Aeromonas hydrophila strain. Estimations of growth and enzyme activity were made within a three-dimensional matrix of conditions: temperature 2-20 degrees C, pH value 4.0-7.5 and water activity (a(w)) 0.95-0.995. A mathematical model was constructed which predicted growth based on increases in cell number. However, although notable effects of extracellular lipases and proteases were detected, it was not possible to model enzymatic activity and prepare a combined model because the data did not follow the characteristic profile that would allow curve-fitting. Nevertheless, the model for microbial growth and information relating to enzyme activity will be made freely available in a database on the internet. PMID:16154655

  16. Chlorophytum borivilianum Polysaccharide Fraction Provokes the Immune Function and Disease Resistance of Labeo rohita against Aeromonas hydrophila

    PubMed Central

    Giri, Sib Sankar; Sen, Shib Sankar; Chi, Cheng; Kim, Hyoun Joong; Yun, Saekil; Park, Se Chang; Sukumaran, V.

    2015-01-01

    The present study aimed to investigate the effects of Chlorophytum borivilianum polysaccharide (CBP), as a dietary supplement administered at varying concentrations with feed (basal diet), on various cytokine-related responses in Labeo rohita fingerlings. Immune parameters and immune-related gene expressions were measured at 3rd, 4th, and 5th week after feeding. The results revealed that dietary administration of CBP at 0.2% and 0.4% for 4 weeks significantly upregulated serum lysozyme and phagocytic activity. Complement C3 and respiratory burst activity (RBA) were significantly higher after 4 weeks of CBP feeding. The immune related genes IL-8, IL-1β, TNF-α, and iNOS were downregulated (P < 0.05) in groups with 0.2% and 0.4% CBP supplemented diets at week 4. Expression of anti-inflammatory cytokines (IL-10 and TGF-β) was also downregulated (P < 0.5) after 4 weeks of feeding with 0.2% to 0.8% CBP. However, five weeks of CBP administration had no significant effect on immune gene expression, except TNF-α and IL-8. Fish fed with 0.4% CBP for 4 weeks showed maximum resistance against Aeromonas hydrophila (73.3% survival) compared to control. From these results, we recommend that CBP administration at 0.4% for 4 weeks could effectively improve immune response and disease resistance in L. rohita. PMID:26649325

  17. Transcriptome analysis of the endangered Chinese giant salamander (Andrias davidianus): Immune modulation in response to Aeromonas hydrophila infection.

    PubMed

    Qi, Zhitao; Zhang, Qihuan; Wang, Zisheng; Ma, Tianyi; Zhou, Jie; Holland, Jason W; Gao, Qian

    2016-01-01

    The endangered Chinese giant salamander (Andrias davidianus) is the largest extant amphibian species. Disease outbreaks represent one of the major factors threatening A. davidianus populations in the wild and the viability of artificial breeding programmes. Development of future immune therapies to eliminate infectious disease in A. davidianus is dependent on a thorough understanding of the immune mechanisms elicited by pathogen encounters. To this end we have undertaken, for the first time in amphibians, differential transcriptome analysis of the giant salamander response to Aeromonas hydrophila, one of the most devastating pathogens affecting amphibian populations. Out of 87,204 non-redundant consensus unigenes 19,216 were annotated, 6834 of which were upregulated and 906 down-regulated following bacterial infection. 2058 unigenes were involved with immune system processes, including 287 differentially expressed unigenes indicative of the impact of bacterial infection on several innate and adaptive immune pathways in the giant salamander. Other pathways not directly associated with immune-related activity were differentially expressed, including developmental, structural, molecular and growth processes. Overall, this work provides valuable insights into the underlying immune mechanisms elicited during bacterial infection in amphibians that may aid in the future development of disease control measures in protecting the Chinese giant salamander. With the unique position of amphibians in the transition of tetrapods from aquatic to terrestrial habitats, our study will also be invaluable towards the further understanding of the evolution of tetrapod immunity. PMID:26620078

  18. Characterization of serum immunoglobulin in channa striata (BLOCH) and kinetics of its response to Aeromonas hydrophila antigen.

    PubMed

    Rauta, P R; Mohanty, J; Garnayak, S K; Sahoo, P K

    2013-01-01

    The immunoglobulin (Ig) from the serum of Channa striata was isolated by gel electroelution and characterized further to understand its nature and subsequent applications in studying the immune response. The purity of the sample was confirmed with the presence of a single band on native gradient PAGE and the molecular weight of ∼897 kDa was determined from the gel. In SDS-PAGE, C. striata Ig was reduced to produce two bands corresponding to H (heavy) (∼72 kDa) and L (light) (∼27 kDa) chain subunits. Polyclonal antiserum against the purified Ig was raised in a rabbit and adsorbed with 10% liver tissue homogenate of C. striata to enhance its specificity. By an indirect ELISA standardized using the adsorbed rabbit antiserum, the normal serum Ig concentration in C. striata was estimated to be 3.48 mg/mL. Further, a kinetic study of specific immunoglobulin response to formalin-killed Aeromonas hydrophila antigen was undertaken using another indirect ELISA, which showed a significant increase in serum immunoglobulin titer from day 2 onwards and reached its peak at day 14. Subsequently, the Ig titer was dropped from day 21 onwards till the completion of the experiment at day 42, although it was at a significantly higher level than the control. PMID:23656248

  19. POTENTIAL FOR GREAT EGRETS (ARDEA ALBA) TO TRANSMIT A VIRULENT STRAIN OF AEROMONAS HYDROPHILA AMONG CHANNEL CATFISH (ICTALURUS PUNCTATUS) CULTURE PONDS.

    PubMed

    Jubirt, Madison M; Hanson, Larry A; Hanson-Dorr, Katie C; Ford, Lorelei; Lemmons, Scott; Fioranelli, Paul; Cunningham, Fred L

    2015-07-01

    Aeromonas hydrophila is a gram-negative, rod-shaped, facultative, anaerobic bacterium that is ubiquitous in freshwater and slightly brackish aquatic environments and infects fish, humans, reptiles, and birds. Recent severe outbreaks of disease in commercial channel catfish (Ictalurus punctatus) aquaculture ponds have been associated with a highly virulent A. hydrophila strain (VAH), which is genetically distinct from less-virulent strains. The epidemiology of this disease has not been determined. Given that A. hydrophila infects birds, we hypothesized that fish-eating birds may serve as a reservoir for VAH and spread the pathogen by flying to uninfected ponds. Great Egrets (Ardea alba) were used in this transmission model because these wading birds frequently prey on farmed catfish. Great Egrets that were fed VAH-infected catfish shed VAH in feces demonstrating their potential to spread VAH. PMID:25984772

  20. Identification of unique DNA sequences present in highly virulent 2009 Alabama isolates of Aeromonas hydrophila

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2009, a disease outbreak caused by A. hydrophila occurred in 48 catfish farms in West Alabama, causing an estimated loss of more than 3 million pounds of food size channel catfish. Virulence studies have revealed that the 2009 isolates of A. hydrophila are at least 200-fold more virulent than a 1...

  1. Chemotaxis towards, adhesion to, and growth in carp gut mucus of two Aeromonas hydrophila strains with different pathogenicity for common carp, Cyprinus carpio L.

    PubMed

    van der Marel, M; Schroers, V; Neuhaus, H; Steinhagen, D

    2008-05-01

    Characteristics that promote bacterial colonization of the intestinal mucosal surface were examined in two strains of the common fish pathogen Aeromonas hydrophila, with different pathogenicity. The characteristics examined were chemotactic activity towards mucus, bacterial adherence to mucus and growth in mucus. Intestinal gut mucus of healthy common carp was used. The results indicate that chemotaxis is not necessary for a bacterium to become pathogenic, but it may be a necessary parameter for a bacterium to be an obligate pathogen. Adhesion also seems to be a factor influencing pathogenicity. The results suggest that higher adhesion to mucus and subsequent growth is associated with differences in pathogenicity. PMID:18355183

  2. CHARACTERIZATION OF AEROMONAS VIRULENCE USING AN IMMUNOCOMPROMISED MOUSE MODEL

    EPA Science Inventory

    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...

  3. OVERVIEW: DISINFECTION OF HELICOBACTER PYLORI AND AEROMONAS SPECIES

    EPA Science Inventory

    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...

  4. A tandem-repeat galectin-9 involved in immune response of yellow catfish, Pelteobagrus fulvidraco, against Aeromonas hydrophila.

    PubMed

    Wang, Yun; Ke, Fei; Ma, Jingjing; Zhou, Shuaibang

    2016-04-01

    Galectins exclusively recognize and bind β-galactoside on cell surface by carbohydrate recognition domain (CRD). In spite of extensive study of mammalian galectin importance in immune system, little is known about that of fish. To study the immune response of yellow catfish to pathogens, a tandem-repeat galectin-9 from yellow catfish was identified and named PfGAL9. Its full-length cDNA was 1314 bp, including a 117 bp of 5' untranslated region (UTR), a 951 bp of open reading frame (ORF), and a 246 bp of 3' UTR. The ORF encoded 316 amino acids (35.12 KDa), shared the highest 78% identity with the predicted galectin-9 of Ictalurus punctatus. This protein possessed two distinct CRDs with two highly conserved sugar binding motifs. Quantitative PCR showed that PfGAL9 was lowly expressed in skin, gill, fin, muscle, heart, and intestine, highly expressed in tested immune tissues (head kidney, trunk kidney, liver, spleen, and blood) in normal body. After inactivated Aeromonas hydrophila challenge, PfGAL9 was remarkably increased in head kidney and liver in a time-dependent manner. The recombinant protein was expressed in Escherichia coli, which not only agglutinated but also bond all examined bacteria. The binding activities are consistent with the size of aggregates formed by agglutinated bacteria. The agglutination must depend on its direct interaction with bacteria. These results suggested that PfGAL9 was involved in the innate immune response against bacterial infection and clearance of pathogens in yellow catfish. PMID:26892795

  5. Novel microbial route to synthesize ZnO nanoparticles using Aeromonas hydrophila and their activity against pathogenic bacteria and fungi

    NASA Astrophysics Data System (ADS)

    Jayaseelan, C.; Rahuman, A. Abdul; Kirthi, A. Vishnu; Marimuthu, S.; Santhoshkumar, T.; Bagavan, A.; Gaurav, K.; Karthik, L.; Rao, K. V. Bhaskara

    2012-05-01

    In the present work, we describe a low-cost, unreported and simple procedure for biosynthesis of zinc oxide nanoparticles (ZnO NPs) using reproducible bacteria, Aeromonas hydrophila as eco-friendly reducing and capping agent. UV-vis spectroscopy, XRD, FTIR, AFM, NC-AFM and FESEM with EDX analyses were performed to ascertain the formation and characterization of ZnO NPs. The synthesized ZnO NPs were characterized by a peak at 374 nm in the UV-vis spectrum. XRD confirmed the crystalline nature of the nanoparticles and AFM showed the morphology of the nanoparticle to be spherical, oval with an average size of 57.72 nm. Synthesized ZnO NPs showed the XRD peaks at 31.75°, 34.37°, 47.60°, 56.52°, 66.02° and 75.16° were identified as (1 0 0), (0 0 2), (1 0 1), (1 0 2), (1 1 0), (1 1 2) and (2 02 ) reflections, respectively. Rietveld analysis to the X-ray data indicated that ZnO NPs have hexagonal unit cell at crystalline level. The size and topological structure of the ZnO NPs was measured by NC-AFM. The morphological characterization of synthesized nanoparticles was analyzed by FESEM and chemical composition by EDX. The antibacterial and antifungal activity was ended with corresponding well diffusion and minimum inhibitory concentration. The maximum zone of inhibition was observed in the ZnO NPs (25 μg/mL) against Pseudomonas aeruginosa (22 ± 1.8 mm) and Aspergillus flavus (19 ± 1.0 mm). Bacteria-mediated ZnO NPs were synthesized and proved to be a good novel antimicrobial material for the first time in this study.

  6. ANALYSIS OF AEROMONAS BY MASS SPECTROMETRY: SPECIATION AND VIRULENCE FACTORS

    EPA Science Inventory

    Introduction:

    A number of bacteria, including Aeromonas hydrophila, are listed on the Environmental Protection Agency's 1998 Contaminant Candidate List (CCL) as research needs. One research priority designated by the CCL is the identification of virulence activity facto...

  7. Hematological and Immunological plasma assays for grass carp (Ctenopharyngodon idella) infected with Aeromonas hydrophila as an immune model in carp aquaculture.

    PubMed

    Li, Lisen; Dang, Yunfei; Shen, Yubang; Xu, Xiaoyan; Huang, Wenji; Li, Jiale

    2016-08-01

    Aeromonas hydrophila is the causative agent of bacterial septicemia, a common disease observed in grass carp, Ctenopharyngodon idella. In our study, C. idella specimens were infected with A. hydrophila, and parameters of Hematological and Immunological plasma parameters were monitored. At blood cell level, levels of red blood cells (RBCs), hematocrit (HCT), and mean corpuscular volume (MCV) showed no differences between the treatment and control groups, but levels of white blood cells (WBCs) increased. The monocyte and neutrophil varied significant according to stimulation by A. hydrophila at 1 DPI, the thrombocyte and lymphocyte at 14 and 21 DPI. At serum level, total protein, lysozyme, and IgM increased at the early infection phase and then decreased at other time points; however, peroxidase levels were significantly lower in the treatment group than that in the control group during the early infection phase. ACH50 was significantly higher in the treatment group than that in the control group during the late infection phase. On the basis of the results, we suggest that innate and adaptive immune mechanisms of C. idella are able to neutralize the virulence factors secreted by A. hydrophila. Our findings would help in understanding the mechanisms underlying resistance to infection by A. hydrophila. PMID:27368540

  8. Chironomids' Relationship with Aeromonas Species.

    PubMed

    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

  9. Expression and activity of recombinant proaerolysin derived from Aeromonas hydrophila cultured from diseased channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proaerolysin-coding gene was cloned from the genomic DNA of A. hydrophila and heterologously expressed in E. coli. The purified recombinant proaerolysin was inactive and could be activated by treatment with proteases, furin and trypsin, and extra-cellular proteins (ECPs, the cell-free supernatant of...

  10. Identification of gyrB and rpoB gene mutations and differentially expressed proteins between a novobiocin-resistant Aeromonas hydrophila catfish vaccine strain and its virulent parent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sequence comparison between the full-length 2412 bp DNA gyrase subunit B (gyrB) gene of a novobiocin resistant Aeromonas hydrophila AH11NOVO vaccine strain and that of its virulent parent strain AH11P revealed 10 missense mutations. Similarly, sequence comparison between the full-length 4092 bp RNA ...

  11. Efficacy of florfenicol, copper sulfate and potassium permanganate in controlling a natural infection of Aeromonas hydrophila and Flavobacterium columnare in sunshine bass, Morone chrysops female x Morone saxatilis male

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sunshine bass (Morone chrysops female ' Morone saxatilis male) naturally infected with Aeromonas hydrophila and Flavobacterium columnare were randomly assigned to six treatments: 1) two treatments of waterborne exposures to copper sulfate (CuSO4), at 2.1 and at 4.2 mg/L (approximately one and two pe...

  12. Effect of effluent from a nitrogen fertilizer factory and a pulp mill on the distribution and abundance of Aeromonas hydrophila in Albemarle Sound, North Carolina

    SciTech Connect

    Hazen, T.C.; Esch, G.W.

    1983-01-01

    The density of Aeromonas hydrophila, standard count bacteria, fecal coliform bacteria, and 18 physical and chemical parameters were measured simultaneously at six sites for 12 months in Albemarle Sound, N.C. One site was above and two sites were below the discharge plume of a Kraft pulping process paper mill. The fourth site was above and the remaining two sites were below the discharge point of a nitrogen fertilizer factory. The impact of the pulp mill on water quality was acute, whereas that of the nitrogen fertilizer factory was chronic and much more subtle. Diffusion chamber studies indicated that A. hydrophila survival is increased by pulp mill effluent and decreased by nitrogen fertilizer factor effluent. From correlation and regression analysis, A. hydrophila was found to be directly affected by phytoplankton density and, thus, indirectly by concentrations of phosphate, nitrate, and total organic carbon. These two point sources are suspect as indirect causes of red-sore disease epizootics, a disease of fish caused by A. hydrophila.

  13. Administration of yeast glucan enhances survival and some non-specific and specific immune parameters in carp (Cyprinus carpio) infected with Aeromonas hydrophila.

    PubMed

    Selvaraj, V; Sampath, K; Sekar, V

    2005-10-01

    Effects of beta-glucan administration on survival and immune modulations were studied in Cyprinus carpio against the bacterial pathogen, Aeromonas hydrophila. Beta-glucan was extracted from Saccharomyces cervisiae and purified. A virulent strain of the pathogen A. hydrophila was collected from infected fish. Different concentrations of beta-glucan were administered to test animals on day 1, 3 and 5 through different routes (intraperitoneal injection (ip), bathing and oral administration). Control and test animals were challenged by ip injection of LD50 concentration of A. hydrophila on day 7 and mortality was observed and Relative Percent Survival (RPS) was calculated. Intraperitoneal injection of 500 microg of glucan significantly enhanced the RPS; bathing and oral administration of glucan did not influence the RPS. On day 7, test animals injected with 100, 500 and 1000 microg of glucan had a significant increase in total blood leucocyte counts and an increase in the proportion of neutrophils and monocytes. Superoxide anion production by kidney macrophages was also elevated. RT-PCR and northern blot analysis of interleukin-1 mRNA showed elevated expression in kidney on day 7 in fish injected with glucan. Glucan had an adjuvant effect on antibody production as pretreatment by injection of 100-1000 microg glucan/fish resulted in the highest antibody titer against A. hydrophila following vaccination. Classical and alternative complement pathways were not affected by glucan administration by any of the three routes. PMID:15863011

  14. Genomic Characterization of the Novel Aeromonas hydrophila Phage Ahp1 Suggests the Derivation of a New Subgroup from phiKMV-Like Family.

    PubMed

    Wang, Jian-Bin; Lin, Nien-Tsung; Tseng, Yi-Hsiung; Weng, Shu-Fen

    2016-01-01

    Aeromonas hydrophila is an opportunistic pathogenic bacterium causing diseases in human and fish. The emergence of multidrug-resistant A. hydrophila isolates has been increasing in recent years. In this study, we have isolated a novel virulent podophage of A. hydrophila, designated as Ahp1, from waste water. Ahp1 has a rapid adsorption (96% adsorbed in 2 min), a latent period of 15 min, and a burst size of 112 PFU per infected cell. At least eighteen Ahp1 virion proteins were visualized in SDS-polyacrylamide gel electrophoresis, with a 36-kDa protein being the predicted major capsid protein. Genome analysis of Ahp1 revealed a linear doubled-stranded DNA genome of 42,167 bp with a G + C content of 58.8%. The genome encodes 46 putative open reading frames, 5 putative phage promoters, and 3 transcriptional terminators. Based on high degrees of similarity in overall genome organization and among most of the corresponding ORFs, as well as phylogenetic relatedness among their DNAP, RNAP and major capsid proteins, we propose a new subgroup, designated Ahp1-like subgroup. This subgroup contains Ahp1 and members previously belonging to phiKMV-like subgroup, phiAS7, phi80-18, GAP227, phiR8-01, and ISAO8. Since Ahp1 has a narrow host range, for effective phage therapy, different phages are needed for preparation of cocktails that are capable of killing the heterogeneous A. hydrophila strains. PMID:27603936

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

    PubMed

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

    2015-07-01

    This study describes the macroscopic and microscopic lesions in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with genetically identified Aeromonas salmonicida, A. hydrophila, and A. veronii species. The genus Aeromonas includes bacteria that naturally inhabit both waterways and organisms. At least 27 Aeromonas species have been identified to date, some of which can cause significant economic losses in aquaculture. As up to 68.8% of Aeromonas isolates may be misidentified in routine biochemical and phenotypic tests, however, reported cases of Aeromonas infection in fish may be wrongly identified. Our findings confirmed that the 3 Aeromonas species studied are associated with septicemia and dermal lesions in rainbow trout. PMID:26130859

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

    PubMed Central

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

    2015-01-01

    This study describes the macroscopic and microscopic lesions in farmed rainbow trout (Oncorhynchus mykiss) naturally infected with genetically identified Aeromonas salmonicida, A. hydrophila, and A. veronii species. The genus Aeromonas includes bacteria that naturally inhabit both waterways and organisms. At least 27 Aeromonas species have been identified to date, some of which can cause significant economic losses in aquaculture. As up to 68.8% of Aeromonas isolates may be misidentified in routine biochemical and phenotypic tests, however, reported cases of Aeromonas infection in fish may be wrongly identified. Our findings confirmed that the 3 Aeromonas species studied are associated with septicemia and dermal lesions in rainbow trout. PMID:26130859

  17. Crystal Structure of the Heteromolecular Chaperone, AscE-AscG, from the Type III Secretion System in Aeromonas hydrophila

    PubMed Central

    Chatterjee, Chiradip; Kumar, Sundramurthy; Chakraborty, Smarajit; Tan, Yih Wan; Leung, Ka Yin; Sivaraman, J.; Mok, Yu-Keung

    2011-01-01

    Background The putative needle complex subunit AscF forms a ternary complex with the chaperones AscE and AscG in the type III secretion system of Aeromonas hydrophila so as to avoid premature assembly. Previously, we demonstrated that the C-terminal region of AscG (residues 62–116) in the hetero-molecular chaperone, AscE-AscG, is disordered and susceptible to limited protease digestion. Methodology/Principal Findings Here, we report the crystal structure of the ordered AscG1–61 region in complex with AscE at 2.4 Å resolution. Helices α2 and α3 of AscE in the AscE-AscG1–61 complex assumes a helix-turn-helix conformation in an anti-parallel fashion similar to that in apo AscE. However, in the presence of AscG, an additional N-terminal helix α1 in AscE (residues 4–12) is observed. PscG or YscG in the crystal structures of PscE-PscF-PscG or YscE-YscF-YscG, respectively, assumes a typical tetratricopeptide repeat (TPR) fold with three TPR repeats and one C-terminal capping helix. By comparison, AscG in AscE-AscG1–61 comprises three anti-parallel helices that resembles the N-terminal TPR repeats in the corresponding region of PscG or YscG in PscE-PscF-PscG or YscE-YscF-YscG. Thermal denaturation of AscE-AscG and AscE-AscG1–61 complexes demonstrates that the C-terminal disordered region does not contribute to the thermal stability of the overall complex. Conclusion/Significance The N-terminal region of the AscG in the AscE-AscG complex is ordered and assumes a structure similar to those in the corresponding regions of PscE-PscG-PscF or YscE-YscF-YscG complexes. While the C-terminal region of AscG in the AscE-AscG complex is disordered and will assume its structure only in the presence of the substrate AscF. We hypothesize that AscE act as a chaperone of the chaperone to keep AscG in a stable but partially disordered state for interaction with AscF. PMID:21559439

  18. CHLORINE DISINFECTION OF AEROMONAS

    EPA Science Inventory

    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...

  19. Adjuvant and immunostimulatory effects of beta-glucan administration in combination with lipopolysaccharide enhances survival and some immune parameters in carp challenged with Aeromonas hydrophila.

    PubMed

    Selvaraj, V; Sampath, K; Sekar, Vaithilingam

    2006-11-15

    Combined effects of beta-glucan and lipopolysaccharide (LPS) on survival and immune response were studied in Cyprinus carpio that were challenged with the pathogen Aeromonas hydrophila. beta-Glucan from Saccharomyces cervisiae and LPS from a virulent strain of A. hydrophila were used in this study. Different concentrations of beta-glucan+LPS mixture were administered on days 1, 7, and 14 through different routes (intraperitoneal injection, bathing, and oral administration). Control and test fish were challenged by intraperitoneal injection of LD50 concentration of A. hydrophila on day 16 and subsequently, mortality and relative percent survival (RPS) were recorded. Intraperitoneal injection elicited 100% RPS even at the lowest concentration (100 microg beta-glucan+10 microg LPS); whereas, oral administration improved RPS rate of carps at higher concentration (1% beta-glucan+0.25% LPS). Bathing did not improve the RPS. Test animals injected with even the minimum dose of the immunomodulators (100 microg beta-glucan+10 microg LPS/fish) had a significant increase in total blood leukocyte counts and an increase in the proportion of neutrophils and monocytes. Superoxide anion production by macrophages was also elevated, which presumably aided the efficient killing of bacterial pathogen. Lower concentration of beta-glucan+LPS had an adjuvant effect on antibody production as pretreatment by injection of 100 microg beta-glucan+10 microg LPS/fish resulted in higher antibody titer against A. hydrophila following vaccination. RT-PCR analyses showed that the expression of interleukin-1beta mRNA did not increase in test fish when compared with the control. Classical and alternative complement pathways were not affected by either the dose or the route of administration of the compounds. It may be concluded that intraperitoneal injection and oral administration, and not the bathing, of beta-glucan+LPS mixture in carp could enhance resistance to challenge by A. hydrophila through

  20. A novel recombinant bivalent outer membrane protein of Vibrio vulnificus and Aeromonas hydrophila as a vaccine antigen of American eel (Anguilla rostrata).

    PubMed

    SongLin, Guo; PanPan, Lu; JianJun, Feng; JinPing, Zhao; Peng, Lin; LiHua, Duan

    2015-04-01

    The immogenicity of a novel vaccine antigen was evaluated after immunized American eels (Anguilla rostrata) with a recombinant bivalent expressed outer membrane protein (OMP) of Vibrio vulnificus and Aeromonas hydrophila. Three groups of eels were intraperitoneal (i.p) injected with phosphate-buffered saline (PBS group), formaline-killed-whole-cell (FKC) of A. hydrophila and V. vulnificus (FKC group) or the bivalent OMP (OMP group). On 14, 21, 28 and 42 days post-vaccination respectively, proliferation of the whole blood cells, titers of specific antibody and lysozyme activities of experimental eels were detected. On 28 day post-vaccination, eels from three groups were challenged by i.p injection of live A. hydrophila or V. vulnificus. The results showed that, compared with the PBS group, proliferation of whole blood cells in OMP group was significant enhanced on 28 days, and the serum titers of anti-A.hydrophila and anti-V. vulnificus antibody in eels of FKC and OMP group were significant increased on 14, 21 and 28d. Lysozyme Activities in serum, skin mucus, liver and kidney were significant changed between the three groups. Relative Percent Survival (RPS) after challenged A. hydrophila in KFC vs. PBS group and OMP vs. PBS group were 62.5% and 50% respectively, and the RPS challenged V. vulnificus in FKC and OMP vs. PBS group were 37.5% and 50% respectively. These results suggest that American eels immunized with the bivalent OMP would positively affect specific as well as non-specific immune parameters and protect against infection by the two pathogens in fresh water farming. PMID:25655329

  1. Influence of carvacrol and 1,8-cineole on cell viability, membrane integrity, and morphology of Aeromonas hydrophila cultivated in a vegetable-based broth.

    PubMed

    de Sousa, Jossana Pereira; de Oliveira, Kataryne Árabe Rimá; de Figueiredo, Regina Celia Bressan Queiroz; de Souza, Evandro Leite

    2015-02-01

    This study investigated the effects of carvacrol (CAR) and 1,8-cineole (CIN) alone (at the MIC) or in combination at subinhibitory amounts (both at 1/8 MIC) on the cell viability, membrane permeability, and morphology of Aeromonas hydrophila INCQS 7966 (A. hydrophila) cultivated in a vegetable-based broth. CAR and CIN alone or in combination severely affected the viability of the bacteria and caused dramatic changes in the cell membrane permeability, leading to cell death, as observed by confocal laser microscopy. Scanning and transmission electron microscopy images of bacterial cells exposed to CAR or CIN or the mixture of both compounds revealed severe changes in cell wall structure, rupture of the plasma membrane, shrinking of cells, condensation of cytoplasmic content, leakage of intracellular material, and cell collapse. These findings suggest that CAR and CIN alone or in combination at subinhibitory amounts could be applied to inhibit the growth of A. hydrophila in foods, particularly as sanitizing agents in vegetables. PMID:25710162

  2. Methanol extract of Nyctanthes arbortristis seeds enhances non-specific immune responses and protects Oreochromis mossambicus (Peters) against Aeromonas hydrophila infection.

    PubMed

    Kirubakaran, C John Wesly; Subramani, Parasuraman Aiya; Michael, R Dinakaran

    2016-04-01

    Immunostimulation using medicinal plant extracts is a promising approach for prevention and control of diseases with reference to sustainable fish farming. Oreochromis mossambicus, dubbed as aquatic chicken is a cultured fish worldwide and a laboratory model organism. Aeromonas hydrophila is one of the major bacterial pathogens in fish farming that causes huge loss to aquaculture industries. In this study, we investigated the efficacy of methanol extract of Nyctanthes arbortristis seeds on disease resistance of O. mossambicus against live virulent A. hydrophila. We also investigated its effect on the non-specific immune parameters such as serum lysozyme, myeloperoxidase, antiprotease and specific immune parameters in terms of specific serum antibody titres assayed by bacterial agglutination test. Our studies indicate that intra-peritoneal administration of 20mg/kg methanol extract increases the Relative Percent Survival (RPS) of O. mossambicus challenged with LD80 of A. hydrophila. Further, both non-specific and specific immune parameters were enhanced by the methanol extract. Further experiments at molecular levels in the laboratory and also efficacy testing at field level are essential before applying this plant product in aquaculture industry. PMID:27033940

  3. Detection of Aeromonas hydrophila DNA oligonucleotide sequence using a biosensor design based on Ceria nanoparticles decorated reduced graphene oxide and Fast Fourier transform square wave voltammetry.

    PubMed

    Jafari, Safiye; Faridbod, Farnoush; Norouzi, Parviz; Dezfuli, Amin Shiralizadeh; Ajloo, Davood; Mohammadipanah, Fatemeh; Ganjali, Mohammad Reza

    2015-10-01

    A new strategy was introduced for ssDNA immobilization on a modified glassy carbon electrode. The electrode surface was modified using polyaniline and chemically reduced graphene oxide decorated cerium oxide nanoparticles (CeO2NPs-RGO). A single-stranded DNA (ssDNA) probe was immobilized on the modified electrode surface. Fast Fourier transform square wave voltammetry (FFT-SWV) was applied as detection technique and [Ru(bpy)3](2+/3+) redox signal was used as electrochemical marker. The hybridization of ssDNA with its complementary target caused a dramatic decrease in [Ru(bpy)3](2+/3+) FFT-SW signal. The proposed electrochemical biosensor was able to detect Aeromonas hydrophila DNA oligonucleotide sequence encoding aerolysin protein. Under optimal conditions, the biosensor showed excellent selectivity toward complementary sequence in comparison with noncomplementary and two-base mismatch sequences. The dynamic linear range of this electrochemical DNA biosensor for detecting 20-mer oligonucleotide sequence of A. hydrophila was from 1 × 10(-15) to 1 × 10(-8) mol L(-1). The proposed biosensor was successfully applied for the detection of DNA extracted from A. hydrophila in fish pond water up to 0.01 μg mL(-1) with RSD of 5%. Besides, molecular docking was applied to consider the [Ru(bpy)3](2+/3+) interaction with ssDNA before and after hybridization. PMID:26454462

  4. Chironomids’ Relationship with Aeromonas Species

    PubMed Central

    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

  5. Effect of salinity and incubation time of planktonic cells on biofilm formation, motility, exoprotease production, and quorum sensing of Aeromonas hydrophila.

    PubMed

    Jahid, Iqbal Kabir; Mizan, Md Furkanur Rahaman; Ha, Angela J; Ha, Sang-Do

    2015-08-01

    The aim of this study was to determine the effect of salinity and age of cultures on quorum sensing, exoprotease production, and biofilm formation by Aeromonas hydrophila on stainless steel (SS) and crab shell as substrates. Biofilm formation was assessed at various salinities, from fresh (0%) to saline water (3.0%). For young and old cultures, planktonic cells were grown at 30 °C for 24 h and 96 h, respectively. Biofilm formation was assessed on SS, glass, and crab shell; viable counts were determined in R2A agar for SS and glass, but Aeromonas-selective media was used for crab shell samples to eliminate bacterial contamination. Exoprotease activity was assessed using a Fluoro™ protease assay kit. Quantification of acyl-homoserine lactone (AHL) was performed using the bioreporter strain Chromobacterium violaceum CV026 and the concentration was confirmed using high-performance liquid chromatography (HPLC). The concentration of autoinducer-2 (AI-2) was determined with Vibrio harveyi BB170. The biofilm structure at various salinities (0-3 %) was assessed using field emission electron microscopy (FESEM). Young cultures of A. hydrophila grown at 0-0.25% salinity showed gradual increasing of biofilm formation on SS, glass and crab shell; swarming and swimming motility; exoproteases production, AHL and AI-2 quorum sensing; while all these phenotypic characters reduced from 0.5 to 3.0% salinity. The FESEM images also showed that from 0 to 0.25% salinity stimulated formation of three-dimensional biofilm structures that also broke through the surface by utilizing the chitin surfaces of crab, while 3% salinity stimulated attachment only for young cultures. However, in marked contrast, salinity (0.1-3%) had no effect on the stimulation of biofilm formation or on phenotypic characters for old cultures. However, all concentrations reduced biofilm formation, motility, protease production and quorum sensing for old culture. Overall, 0-0.25% salinity enhanced biofilm formation

  6. Effects of dietary cholesterol on antioxidant capacity, non-specific immune response, and resistance to Aeromonas hydrophila in rainbow trout (Oncorhynchus mykiss) fed soybean meal-based diets.

    PubMed

    Deng, Junming; Kang, Bin; Tao, Linli; Rong, Hua; Zhang, Xi

    2013-01-01

    This study evaluated the effects of dietary cholesterol on antioxidant capacity, non-specific immune response and resistance to Aeromonas hydrophila in rainbow trout (Oncorhynchus mykiss) fed soybean meal-based diets. Fish were fed diets supplemented with graded cholesterol levels (0 [control], 0.3, 0.6, 0.9, 1.2, and 1.5%) for nine weeks. The fish were then challenged by A. hydrophila and their survival rate recorded for the next week. Dietary cholesterol supplementation generally increased the serum and hepatic superoxide dismutase (SOD), glutathione-peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (TAC) activities, but decreased the serum and hepatic malondialdehyde (MDA) contents. Further, the hepatic CAT and serum SOD, CAT, and TAC activities were significantly higher in fish fed diets supplemented with 0.9 or 1.2% cholesterol compared to those fed the control diet, whereas the serum and hepatic MDA contents were significantly lower. The respiratory burst activity, alternative complement activity, and hepatic lysozyme activity increased steadily when the supplemental cholesterol was increased by up to 1.2% and then declined with further addition. The serum lysozyme activity and phagocytic activity increased steadily with increasing dietary supplemental cholesterol level up to 0.9% and then declined with further addition. Dietary cholesterol supplementation generally enhanced the protection against A. hydrophila infection, and fish fed diets supplemented with 0.9 or 1.2% cholesterol exhibited the highest post-challenge survival rate. The results indicated that cholesterol may be under-supplied in rainbow trout fed soybean meal-based diets, and dietary cholesterol supplementation (0.9-1.2%) contributed to improved immune response and disease resistance of rainbow trout against A. hydrophila. PMID:23207478

  7. Isolation of potential probiotic Bacillus spp. and assessment of their subcellular components to induce immune responses in Labeo rohita against Aeromonas hydrophila.

    PubMed

    Ramesh, Dharmaraj; Vinothkanna, Annadurai; Rai, Amit Kumar; Vignesh, Venkada Subramanian

    2015-08-01

    Bacillus species isolated from the gut of healthy Labeo rohita (Hamilton) were screened for antibacterial activity against selected fish pathogens. Among the isolates, KADR5 and KADR6 showed antibacterial activity, tolerated low pH and high bile concentrations and were susceptibility to various antibiotics. Based on morphological and biochemical tests and 16S rRNA gene analysis the probiotic strains KADR5 and KADR6 were identified as Bacillus licheniformis and Bacillus pumilus, respectively. The immune stimulatory effect of subcellular components of probiotic Bacillus licheniformis KADR5 and Bacillus pumilus KADR6 in L. rohita against Aeromonas hydrophila infection was studied. Fish were immunized intraperitoneally in case of subcellular components [cell wall proteins (CWPs), extracellular proteins (ECPs), whole cell proteins (WCPs)] and orally in case of live cells (10(8) CFU/g of feed). After 14th day of administration, fishes from each group were challenged intraperitoneally with 0.1 ml of A. hydrophila cell suspension in PBS (10(5) cells ml(-1)). Groups immunized with subcellular components and live cells had significantly lower mortalities of 20-40% and 23-33%, respectively in comparison to control (80% mortality). The non specific immune factors in the cellular components and viable cells of the probiotics increased the expression of lysozyme and respiratory burst. Use of WCPs and CWPs resulted in better protection against A. hydrophila in L. rohita. Our results clearly reflect the potential of cellular components of the probiotics Bacillus species for the protection of fish against A. hydrophila infection by enhancing the immune response. PMID:25917974

  8. In vivo bactericidal effect of Melaleuca alternifolia essential oil against Aeromonas hydrophila: Silver catfish (Rhamdia quelen) as an experimental model.

    PubMed

    F Souza, Carine; Baldissera, Matheus D; A Vaucher, Rodrigo; Lopes, Leonardo Q S; Vizzotto, Bruno S; Raffin, Renata P; Santos, Roberto C V; L da Veiga, Marcelo; U M da Rocha, Maria Izabel; Stefani, Lenita M; Baldisserotto, Bernardo

    2016-09-01

    Aeromonas hydrophila is one of the main causative agent of high mortality and significative economic losses in aquaculture and has become increasingly resistant to conventional antibiotics. One feasible alternative to control and treat it is the use of essential oils. This study aimed to evaluate A. hydrophila susceptibility to tea tree oil (TTO-Melaleuca alternifolia) in vivo, and the effect of this treatment. In vivo tests were performed using silver catfish (Rhamdia quelen) as the experimental model. Silver catfish were treated with TTO at 25 and 50 μL/L for seven days before infection. After seven days, the fish were inoculated with A. hydrophila via intramuscularly. Treatment with TTO at 50 μL/L was able to extend longevity of infected fish, and showed 88% of therapeutic success, even though it did not show curative efficacy. TTO treatment was not toxic under these tested concentrations, since biomarkers of hepatic and renal functions were not affected, and the concentration of 50 μL/L was able to prevent increased levels of aspartate aminotransferase. There was no significative differences regarding hematological parameters (p < 0.05). Treatment with TTO 50 μL/L was able to reduce histopathological alterations usually caused by this type of bacteria in the gills, but it was unable to reduce hepatic histopathological alterations. Our results showed, for the first time, that TTO has high activity against A. hydrophila and proved to be a natural alternative to prevent and control this pathogen. PMID:27392700

  9. Effects of hirami lemon, Citrus depressa Hayata, leaf meal in diets on the immune response and disease resistance of juvenile barramundi, Lates calcarifer (bloch), against Aeromonas hydrophila.

    PubMed

    Shiu, Ya-Li; Lin, Hsueh-Li; Chi, Chia-Chun; Yeh, Shinn-Pyng; Liu, Chun-Hung

    2016-08-01

    The present study was conducted to evaluate the dietary supplementation of leaf meal from Citrus depressa Hayata on the growth, innate immune response, and disease resistance of juvenile barramundi, Lates calcarifer. Four diets were formulated to contain 0% (control), 1% (C1), 3% (C3), and 5% (C5) leaf meal, respectively. During a 56 d feeding trial, fish survival, growth performance, and feed efficiency were not significantly different among all groups. For immune response, respiratory burst, superoxide dismutase and lysozyme activities were not significantly different among all groups. However, fish fed the C5 diet for 56 d had significantly higher phagocytic activity. Also, fish fed C3 and C5 diets had significantly higher Mx gene expressions in spleens and head kidneys with nerve necrosis virus injections after 24 h. Disease resistance against Aeromonas hydrophila was increased by the C5 diet. In this study, barramundi fed on a diet containing 5% C. depressa Hayata leaf meal had significantly better innate immune response and disease resistance against A. hydrophila. PMID:27265807

  10. The main Aeromonas pathogenic factors.

    PubMed

    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

  11. Microbial levan in the diet of Labeo rohita Hamilton juveniles: effect on non-specific immunity and histopathological changes after challenge with Aeromonas hydrophila.

    PubMed

    Gupta, S K; Pal, A K; Sahu, N P; Dalvi, R; Kumar, V; Mukherjee, S C

    2008-09-01

    A 60-day feeding trial was conducted to study the immuno-protective effect of microbial levan on Labeo rohita juveniles challenged with Aeromonas hydrophila. Six purified diets were prepared with different levels of microbial levan: control (no levan), T1 (Basal + 0.25%), T2 (Basal + 0.50%), T3 (Basal + 0.75%), T4 (Basal + 1%) and T5 (Basal + 1.25%), fed to six groups of fish in triplicate. Among the treatment groups the haemoglobin content and total leucocyte count were increased with a dietary supplementation of levan at 1% or more. An increasing trend for total erythrocyte count was observed with increasing level of dietary levan. Lower levan-supplemented groups showed a higher albumin/globulin ratio. As the levan supplementation was increased, there was a gradual increase in serum lysozyme activity and respiratory burst activity [nitroblue tetrazolium (NBT) assay] reduction values. The highest lysozyme activity and NBT were observed in the T5 group although this was similar to the T4 group (P > 0.05). No significant histo-architectural changes were associated with dietary levan levels. After challenge with A. hydrophila, moderately degenerated hepatocytes, oedema and leucocytic infiltration in parenchymatous tissues, and extensive haemorrhage and haemosiderosis in the kidney were observed in the control group. However, the T5 group supplemented with 1.25% levan showed infiltrating leucocytes in the liver while the kidney showed only moderate degeneration of renal tubules. The relative survival per cent of juveniles after challenge with A. hydrophila was the highest in the T5 group followed by T4. This suggests that microbial levan at 1.25% can be used as dietary immunostimulant for L. rohita juveniles. PMID:18786027

  12. Identification, characterization and expression analysis of ERK2 in Chinese mitten crab Eriocheir sinensis after challenge with LPS and Aeromonas hydrophila.

    PubMed

    Xu, Haisheng; Lyu, Sunjian; Li, Yiqun; Xu, Jiehao; Lu, Binjie; Zhao, Jing

    2016-05-01

    Farming of Eriocheir sinensis was seriously threaten by the infection of opportunistic pathogens, especially the gram-negative bacterium. In this paper, we analyzed the sequence of extracellular signal-regulated kinases 2 (ERK2) of E. sinensis (EsERK2) and its expression levels after challenge with LPS and Aeromonas hydrophila in both in vivo and in vitro examination. The full-length cDNA sequence of EsERK2 was 2455 bp in size with an open reading frame (ORF) of 1095 bp, encoding the protein of 365 amino acids. It owned a predicted molecular mass of 42.4 kDa and a theoretical isoelectric point (pI) of 5.93. EsERK2 was distributed in all examined tissues including haemocyte, gonad, hepatopancreas, gill, muscle heart, stomach and intestine, but its expression level was significantly higher in hepatopancreas than it in other examined tissues. The expression level of EsERK2 increased significantly after LPS challenge at 2 h (P < 0.05), and then gradually increased and reached highest at 16 h. However, its expression level decreased significantly after A. hydrophila challenge at 4 h, and then gradually decreased till 24 h (P < 0.05), and returned to its initial value at 36 h. According to the immunofluorescence assay and western blotting assay, EsERK2 was found to be distributed mainly in cytoplasm of haemocyte, and its expression level showed a prominent boost in primary cultured haemocytes after challenge with LPS and A. hydrophila in vitro. These results indicated that the expression of EsERK2 was sensitive to the exterior stimulants and its encoding protein might be associated with the signaling transduction in response to exterior pathogens in E. sinensis. PMID:27018024

  13. Mutational analysis of the zinc- and substrate-binding sites in the CphA metallo-beta-lactamase from Aeromonas hydrophila.

    PubMed

    Bebrone, Carine; Anne, Christine; Kerff, Frédéric; Garau, Gianpiero; De Vriendt, Kris; Lantin, Raphaël; Devreese, Bart; Van Beeumen, Jozef; Dideberg, Otto; Frère, Jean-Marie; Galleni, Moreno

    2008-08-15

    The subclass B2 CphA (Carbapenemase hydrolysing Aeromonas) beta-lactamase from Aeromonas hydrophila is a Zn(2+)-containing enzyme that specifically hydrolyses carbapenems. In an effort to evaluate residues potentially involved in metal binding and/or catalysis (His(118), Asp(120), His(196) and His(263)) and in substrate specificity (Val(67), Thr(157), Lys(224) and Lys(226)), site-directed mutants of CphA were generated and characterized. Our results confirm that the first zinc ion is in interaction with Asp(120) and His(263), and thus is located in the 'cysteine' zinc-binding site. His(118) and His(196) residues seem to be interacting with the second zinc ion, as their replacement by alanine residues has a negative effect on the affinity for this second metal ion. Val(67) plays a significant role in the binding of biapenem and benzylpenicillin. The properties of a mutant with a five residue (LFKHV) insertion just after Val(67) also reveals the importance of this region for substrate binding. This latter mutant has a higher affinity for the second zinc ion than wild-type CphA. The T157A mutant exhibits a significantly modified activity spectrum. Analysis of the K224Q and N116H/N220G/K224Q mutants suggests a significant role for Lys(224) in the binding of substrate. Lys(226) is not essential for the binding and hydrolysis of substrates. Thus the present paper helps to elucidate the position of the second zinc ion, which was controversial, and to identify residues important for substrate binding. PMID:18498253

  14. Peperomia pellucida leaf extract as immunostimulator in controlling motile aeromonad septicemia due to Aeromonas hydrophila in red hybrid tilapia, Oreochromis spp. farming

    PubMed Central

    Lee, S. W.; Sim, K. Y.; Wendy, W.; Zulhisyam, A. K.

    2016-01-01

    Aim: This study was revealed the potential of Peperomia pellucida leaf extract as an immunostimulator agent in controlling motile aeromonad septicemia due to Aeromonas hydrophila in red hybrid tilapia, Oreochromis sp. Materials and Methods: In the present study, minimum inhibitory concentration (MIC) of P. pellucida leaf extract against A. hydrophila was determined through two-fold microbroth dilution method. The plant extract was screening for its active compound using a gas chromatograph mass spectrometer, and the effectiveness of P. pellucida leaf extract as an immunostimulator agent was evaluated. The experimental fish were fed with medicated feed at three different concentrations (25 mg/kg, PP-25; 50 mg/kg, PP-50; and 100 mg/kg, PP-100) of P. pellucida leaf extract for 1 week before they were intraperitoneally exposed to A. hydrophila. Enzyme-linked immunosorbent assay was carried out to determine the value of antibody response to A. hydrophila in fish from a group of fish that received medicated feed, and the percentage of total cumulative mortality of the experimental fish were observed at the end of the experiment. Results: The results showed that the major bioactive compound is phytol (40%), and the MIC value was 31.5 mg/L. The value of antibody response to A. hydrophila in fish from a group of fish which received medicated feed (PP-25, 0.128±0.014 optical density [OD]; PP-50, 0.132±0.003 OD; and PP-100, 0.171±0.02 OD) was found significantly higher (p<0.05) compared to fish did not receive medicated feed (0.00 OD). Whereas, percentage cumulative mortality of fish from all groups of fish received medicated feed (PP-25, 18.0±3.2%; PP-50, 18.2±2.8%; and PP-100, 17.7±1.8%) were found significantly lower (p<0.05) compared to a group of fish did not receive medicated feed (83.2±1.4%). Conclusion: The findings of the present study indicated the huge potential of P. pellucida leaf extract as natural immunostimulator agent for aquaculture uses. PMID

  15. Molecular cloning of Japanese eel Anguilla japonica TNF-α and characterization of its expression in response to LPS, poly I:C and Aeromonas hydrophila infection

    NASA Astrophysics Data System (ADS)

    Feng, Jianjun; Guan, Ruizhang; Guo, Songlin; Lin, Peng; Zadlock, Frank

    2014-09-01

    As a potent pleiotropic cytokine, tumor necrosis factor-alpha (TNF-α) plays an important role in innate immune responses. The cDNA sequence and genomic structure of the TNF-α gene ( Aj TNF-α) in the Japanese eel ( Anguilla japonica) were identified and characterized. The full-length AjTNF-α cDNA was 1 546 bp, including a 5'-untranslated region (UTR) of 13 bp, a 3'-UTR of 879 bp and an open reading frame of 654 bp encoding a protein of 218 amino acids. The full-length genomic sequence of AjTNF-α was 2 392 bp and included four exons and three introns. The putative AjTNF-α protein contained TNF family signature motifs, including a protease cleavage site, a transmembrane domain and two conserved cysteine residues. Quantitative real-time reverse transcription PCR analysis revealed AjTNF-α expression in a wide range of tissues, with predominant expression in blood and liver. Lower levels of expression were seen in spleen, gills, kidney, intestine, heart, and skin, with very low levels in muscle. The modulation of AjTNF-α expression after injection of eels with lipopolysaccharide (LPS), the viral mimic, poly I:C, or Aeromonas hydrophila was assessed in blood, liver, and kidney. In blood, TNF-α mRNA levels increased rapidly and then rapidly decreased after stimulation with LPS, poly I:C or A. hydrophila. However, the response to LPS and A. hydrophila peaked at 6 h while for poly I:C the peak was at 12 h. In liver, after injection with A. hydrophila, an up- and down-regulation of AjTNF-α expression occurred twice, peaking at 6 h and 24 h, respectively. No remarkable increase of AjTNF-α expression appeared in liver until 72 h after LPS or poly I:C treatment. In kidney, AjTNF-α expression increased significantly only at 72 h post-stimulation with LPS or A. hydrophila. Our results suggest that AjTNF-α plays an important role in fish in the defense against viral and bacterial infection.

  16. Aeromonas species in foods.

    PubMed

    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

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

    PubMed

    Alhazmi, Mohammad Ismail

    2015-01-01

    Aeromonas spp. are opportunistic pathogens causing a broad spectrum of human illnesses like gastroenteritis, chronic diarrhea, wound infections, peritonitis, urinary tract infections, and septicemia. Their ability to grow in foods stored in a refrigerator poses a substantial threat for human consumption. We investigated the prevalence of Aeromonas from commercial food products across Riyadh, Saudi Arabia. A total of 250 samples were randomly collected and processed for the isolation and identification of Aeromonas by morphological and biochemical means and for their identification by PCR. A total of 102 strains of Aeromonas were isolated, including 47% from raw meat samples, 34% from raw fish samples, and 18.6% from milk and dairy products; 56.8% were identified as A. hydrophila and 43.1% as A. sobria. Antibiotic susceptibility tests done revealed 100% sensitivity to chloramphenicol, colistin, ciprofloxacin, and nitrofurantoin. 16S rDNA PCR revealed the presence of the 953 bp fragment in all the strains. The present investigation suggested the occurrences of A. sobria and A. hydrophila in human consumable stored and refrigerated foods. PMID:26268974

  18. Dietary supplementation with Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus oryzae enhance immunity and disease resistance against Aeromonas hydrophila and Streptococcus iniae infection in juvenile tilapia Oreochromis niloticus.

    PubMed

    Iwashita, Marina Keiko P; Nakandakare, Ivan B; Terhune, Jeffery S; Wood, Theresa; Ranzani-Paiva, Maria José T

    2015-03-01

    A feeding trial was conducted to investigate the effects of dietary administration of probiotic with Bacillus subtilis, Aspergillus oryzae and Saccharomyces cerevisiae on growth, innate immune response, Hemato-immunological parameters and disease resistance of Nile tilapia, Oreochromis niloticus. Animals were distributed in three equal groups, each of five replicates and received one of the following experimental diets for four weeks: Control, non-supplemented diet; 5 g kg(-1) probiotic mixture (B. subtilis 1.5 × 10(9) CFU g(-1), S. cerevisiae 10(9) CFU g(-1) and A. oryzae 2 × 10(9) CFU g(-1)); and 10 g kg(-1) probiotic mixture (B. subtilis 3.0 × 10(9) CFU g(-1), S. cerevisiae 2.0 × 10(9) CFU g(-1) and A. oryzae 4.0 × 10(9) CFU g(-1)). The respiratory burst activity, white blood cells and hematological parameters were evaluated after four, five and six weeks of feeding. At the end of the growth trial, fish were sampled for intestinal microbiology and challenged by intraperitoneal injection of LD50 concentration of Aeromonas hydrophila and Streptococcus iniae. Mortality was recorded for the following 3 weeks. Results showed that administration of the probiotic had no significant effect on the growth rates of Nile tilapias, although the fish fed probiotics had better feed conversion. Respiratory burst activity, erythrocyte fragility and levels of white blood cells were significantly improved in tilapias fed diet supplemented with probiotic levels (P < 0.05), which may exhibit up-regulating effects on tilapia immune parameters. The cumulative mortality after A. hydrophila and S. iniae challenge decreased in tilapias fed with probiotic (P < 0.05). The present study demonstrated the potential of B. subtilis, S. cerevisiae and A. oryzae combined as beneficial dietary probiotic in juvenile O. niloticus. PMID:25530581

  19. Differential expression of interleukin-12 p35 and p40 subunits in response to Aeromonas hydrophila and Aquareovirus infection in grass carp, Ctenopharyngodon idella.

    PubMed

    Pandit, N P; Shen, Y B; Xu, X Y; Yu, H Y; Wang, W J; Wang, R Q; Xuan, Y F; Li, J L

    2015-01-01

    The grass carp (Ctenopharyngodon idella) aquaculture industry in Asia is prone to bacterial and viral hemorrhagic diseases. Effective adjuvants for vaccine formulation are the need of the hour for control of these diseases and long-term sustainability of grass carp farming. In this study, the involvement of interleukin-12 (IL-12) from grass carp (gcIL‑12) in anti-bacterial and anti-viral immune responses was demonstrated via expression profiles of gcIL-12 subunits in immune tissues of the fish, following infection by Aeromonas hydrophila and Aquareovirus. Additionally, cDNA of the gcIL-12 subunits, p35 and p40 was cloned and characterized. We found that most of the structurally and functionally important features of vertebrate orthologues were conserved in gcIL-12 subunits, p35 and p40, with some features specific to grass carp. High levels of gcIL-12 p35 expression in the brain and gills suggest that IL-12 plays an important role in neural and immune systems. High expression levels in the heart, blood, and immune-related tissues suggest an important role in circulation and the immune system as well. Infections by both, A. hydrophila and Aquareovirus stimulated the mRNA expression of gcIL-12 subunits, p35 and p40 in most immune tissues. Significant upregulation or downregulation of gcIL-12 subunits, p35 and p40 by bacterial and viral infection confirms their potential role in anti-bacterial and anti-viral immune responses in fish. PMID:25730056

  20. Clinical significance of Aeromonas species isolated from patients with diarrhea.

    PubMed Central

    Moyer, N P

    1987-01-01

    A total of 248 strains of Aeromonas spp. were isolated from 3,334 human fecal specimens submitted to a state public health laboratory over a 2-year period to be cultured for enteric pathogens. Cary-Blair transport medium, blood ampicillin agar, and alkaline peptone water enrichment provided optimal recovery of Aeromonas spp. A questionnaire requesting clinical and epidemiological information was sent to physicians, who submitted stool samples for testing, with each laboratory report for 107 consecutive stool isolates of Aeromonas spp. The 56 questionnaires which were completed and returned were analyzed to determine the seasonal distribution of illness and the age and sex distribution of patients; characteristic symptoms; and predisposing factors for gastrointestinal disease caused by Aeromonas spp. It was concluded that some A. hydrophila, A. sobria, and A. caviae strains are capable of causing diarrhea and that antibiotic therapy and the drinking of untreated water are significant risk factors for susceptible hosts. PMID:3693537

  1. Multifocal Aeromonas Osteomyelitis in a Child with Leukemia.

    PubMed

    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

  2. Multifocal Aeromonas Osteomyelitis in a Child with Leukemia

    PubMed Central

    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

  3. Trigonella foenum-graceum (Seed) Extract Interferes with Quorum Sensing Regulated Traits and Biofilm Formation in the Strains of Pseudomonas aeruginosa and Aeromonas hydrophila

    PubMed Central

    Husain, Fohad Mabood; Ahmad, Iqbal; Khan, Mohd Shahnawaz; Al-Shabib, Nasser Abdulatif

    2015-01-01

    Trigonella foenum-graecum L. (Fenugreek) is an important plant of the Leguminosae family known to have medicinal properties. However, fraction based antiquorum sensing and antibiofilm activities have not been reported from this plant. In the present study T. foenum-graecum seed extract was sequentially fractionated and sub-MICs were tested for above activities. The methanol fraction of the extract demonstrated significant inhibition of AHL regulated virulence factors: protease, LasB elastase, pyocyanin production, chitinase, EPS, and swarming motility in Pseudomonas aeruginosa PAO1 and PAF79. Further, QS dependent virulence factor in the aquatic pathogen Aeromonas hydrophila WAF38 was also reduced. Application of T. foenum-graecum seed extract to PAO1, PAF79, and WAF38 decreased the biofilm forming abilities of the pathogens by significant levels. The extract also exhibited reduced AHL levels and subsequent downregulation of lasB gene. In vivo study showed an enhanced survival of PAO1-preinfected C. elegans after treatment with extract at 1 mg/mL. Further, the major compound detected by GC-MS, caffeine, reduced the production of QS regulated virulence factors and biofilm at 200 µg/mL concentration indicating its role in the activity of the methanol extract. The results of the present study reveal the potential anti-QS and antibiofilm property of T. foenum-graceum extract and caffeine. PMID:26000026

  4. In vitro antibacterial activities of ethanol extract of iranian propolis (EEIP) against fish pathogenic bacteria (Aeromonas hydrophila, Yersinia ruckeri & Streptococcus iniae)

    PubMed Central

    Tukmechi, Amir; Ownagh, Abdolghaffar; Mohebbat, Ali

    2010-01-01

    The “in vitro” antibacterial activity of ethanol extract of propolis (EEIP) from Urmia, Iran was investigated against three prevalent species of fish bacterial pathogens including: Aeromonas hydrophila LMG 3770, Yersinia ruckeri LMG 3279 and Streptococcus iniae LMG 14520. In this study two standard susceptibility testing techniques (Micro-broth dilution method and Agar-well diffusion method) were used to evaluation of the antibacterial activity of EEIP against the mentioned micro-organisms. Also the chemical composition of propolis was determined by the method of Gas chromatography-mass spectrometry (GC-MS). Twenty-six compounds were identified by gas chromatography–mass spectrometry analysis. Results showed Chemical composition of EEIP contained significant amounts of flavonoids, Sesquiterpenes – mainly Eudesmol and Caryophyllene oxide - aromatic acid, and low amounts of aldehydes and triterpens. Furthermore the ethanol extract of propolis inhibited the growth of all examined micro-organisms with the highest antimicrobial activity against Gram-positive bacteria Streptococcus iniae. Ethanol did not influence the antimicrobial effect of EEIP. These antibacterial properties would warrant further studies on the clinical applications of propolis in aquaculture field. PMID:24031591

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

    PubMed Central

    Kivanc, Merih; Yilmaz, Meral; Demir, Filiz

    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 then selected isolates from different phenotypes (VITEK types) were identified using the DuPont Qualicon RiboPrinter® system. Aeromonas spp. was detected only in the samples from the Porsuk River. According to the results obtained with the VITEK system, our isolates were 13% Aeromonas hydrophila, 37% Aeromonas caviae, 35% Pseudomonas putida, and 15% Pseudomonas acidovorans. In addition Pseudomonas sp., Pseudomonas maltophila, Aeromonas salmonicida, Aeromonas hydrophila, and Aeromonas media species were determined using the RiboPrinter® system. The samples taken from the Porsuk River were found to contain very diverse Aeromonas populations that can pose a risk for the residents of the city. On the other hand, drinking water and tap water of the City are free from Aeromonas pathogens and seem to be reliable water sources for the community. PMID:24031613

  6. Evaluation of the roles played by Hcp and VgrG type 6 secretion system effectors in Aeromonas hydrophila SSU pathogenesis

    PubMed Central

    Sha, Jian; Rosenzweig, Jason A.; Kozlova, Elena V.; Wang, Shaofei; Erova, Tatiana E.; Kirtley, Michelle L.; van Lier, Christina J.

    2013-01-01

    Aeromonas hydrophila, a Gram-negative bacterium, is an emerging human pathogen equipped with both a type 3 and a type 6 secretion system (T6SS). In this study, we evaluated the roles played by paralogous T6SS effector proteins, hemolysin co-regulated proteins (Hcp-1 and -2) and valine glycine repeat G (VgrG-1, -2 and -3) protein family members in A. hydrophila SSU pathogenesis by generating various combinations of deletion mutants of the their genes. In addition to their predicted roles as structural components and effector proteins of the T6SS, our data clearly demonstrated that paralogues of Hcp and VgrG also influenced bacterial motility, protease production and biofilm formation. Surprisingly, there was limited to no observed functional redundancy among and/or between the aforementioned T6SS effector paralogues in multiple assays. Our data indicated that Hcp and VgrG paralogues located within the T6SS cluster were more involved in forming T6SS structures, while the primary roles of Hcp-1 and VgrG-1, located outside of the T6SS cluster, were as T6SS effectors. In terms of influence on bacterial physiology, Hcp-1, but not Hcp-2, influenced bacterial motility and protease production, and in its absence, increases in both of the aforementioned activities were observed. Likewise, VgrG-1 played a major role in regulating bacterial protease production, while VgrG-2 and VgrG-3 were critical in regulating bacterial motility and biofilm formation. In an intraperitoneal murine model of infection, all Hcp and VgrG paralogues were required for optimal bacterial virulence and dissemination to mouse peripheral organs. Importantly, the observed phenotypic alterations of the T6SS mutants could be fully complemented. Taking these results together, we have further established the roles played by the two known T6SS effectors of A. hydrophila by defining their contributions to T6SS function and virulence in both in vitro and in vivo models of infection. PMID:23519162

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Detection of goldfish haematopoietic necrosis herpes virus (Cyprinid herpesvirus-2) with multi-drug resistant Aeromonas hydrophila infection in goldfish: First evidence of any viral disease outbreak in ornamental freshwater aquaculture farms in India.

    PubMed

    Sahoo, P K; Swaminathan, T Raja; Abraham, Thangapalam Jawahar; Kumar, Raj; Pattanayak, S; Mohapatra, A; Rath, S S; Patra, Avijit; Adikesavalu, Harresh; Sood, Neeraj; Pradhan, P K; Das, B K; Jayasankar, P; Jena, J K

    2016-09-01

    This outbreak report details of a mortality event where Cyprinid herpes virus-2 (CyHV-2) was detected in association with multidrug-resistant Aeromonas hydrophila infection in goldfish, Carassius auratus, from commercial farms. The goldfish exhibited large scale haemorrhages on the body, fins and gills, lepidorthosis, necrosed gills, protruded anus and shrunken eyes. White nodular necrotic foci in spleen and kidneys were noticed, along with necrosis and fusion of gill lamellae. Transmission electron microscopy of affected tissues revealed the presence of mature virus particles. Involvement of CyHV-2 was confirmed by PCR, sequencing and observed cytopathic effect in koi carp fin cell line along with experimental infection study. A bacterium isolated from the internal organs of affected fish was found to be pathogenic Aeromonas hydrophila having resistance to more than 10 classes of antibiotics. We postulate that CyHV-2 was the primary etiological agent responsible for this outbreak with secondary infection by A. hydrophila. The experimental infection trials in Labeo rohita and koi carp by intraperitoneal challenge with CyHV-2 tissue homogenates failed to reproduce the disease in those co-cultured fish species. This is the first report of a viral disease outbreak in organised earthen ornamental fish farms in India and bears further investigation. PMID:27172876

  9. The Genus Aeromonas: Taxonomy, Pathogenicity, and Infection

    PubMed Central

    Janda, J. Michael; Abbott, Sharon L.

    2010-01-01

    Summary: Over the past decade, the genus Aeromonas has undergone a number of significant changes of practical importance to clinical microbiologists and scientists alike. In parallel with the molecular revolution in microbiology, several new species have been identified on a phylogenetic basis, and the genome of the type species, A. hydrophila ATCC 7966, has been sequenced. In addition to established disease associations, Aeromonas has been shown to be a significant cause of infections associated with natural disasters (hurricanes, tsunamis, and earthquakes) and has been linked to emerging or new illnesses, including near-drowning events, prostatitis, and hemolytic-uremic syndrome. Despite these achievements, issues still remain regarding the role that Aeromonas plays in bacterial gastroenteritis, the extent to which species identification should be attempted in the clinical laboratory, and laboratory reporting of test results from contaminated body sites containing aeromonads. This article provides an extensive review of these topics, in addition to others, such as taxonomic issues, microbial pathogenicity, and antimicrobial resistance markers. PMID:20065325

  10. Clinical Implications of Species Identification in Monomicrobial Aeromonas Bacteremia

    PubMed Central

    Wu, Chi-Jung; Chen, Po-Lin; Hsueh, Po-Ren; Chang, Ming-Chung; Tsai, Pei-Jane; Shih, Hsin-I; Wang, Hsuan-Chen; Chou, Pei-Hsin; Ko, Wen-Chien

    2015-01-01

    Background 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. Methodology/Principal Findings 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: blaAQU-1, blaMOX, or blaCepH was present in A. dhakensis, A. caviae, or A. hydrophila, respectively, and blaCphA 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. Conclusions/Significance Characteristics of Aeromonas bacteremia vary between species. A. dhakensis prevalence and its associated poor outcomes suggest it an important human pathogen. PMID:25679227

  11. Antibiogram characterization and putative virulence genes in Aeromonas species isolated from pig fecal samples.

    PubMed

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

    2016-06-01

    Aeromonas species are broadly distributed in nature and agricultural environments and have been isolated from feces, bedding, and drinking water of healthy pigs. We assessed the incidence, virulence properties, and antimicrobial resistance profile of Aeromonas spp., isolated from pig feces. Antibiogram was done using the disc diffusion methods, and polymerase chain reaction was used for the detection of putative virulence genes. Identification of isolates revealed three phenotypic species with percentage distribution as follows: Aeromonas hydrophila 23 (45.1 %), Aeromonas caviae 16 (31.4 %), and Aeromonas sobria 12 (23.5 %). All Aeromonas isolates in the study were absolutely susceptible to cefotaxime and resistant to penicillin. A. cavaie and A. sobria demonstrated absolute susceptibility against ciprofloxacin and streptomycin. Aeromonas species showed varied susceptibility to cephalothin as follows: A. hydrophila 78.3 %, A. cavaie 93.7 %, and A. sobria 91.7 %. The percentage distribution of virulence genes among Aeromonas isolates were as follows: Aerolysin (aer) 74.5 %, flagellin gene (fla) 68.6 %, cytotoxin (hly A) 43.1 %, lipase (lip) 39.2 %, enterotoxic activities (ast) 31.3 %, and cytotonic gene (alt) 13.7 %. Reports from this study shows that Aeromonas species isolated from pig fecal samples are multi-drug resistant and possess virulence potential which may result to possible risk of human or animal infection and likely contamination of food and water from this sources. PMID:26971520

  12. Aeromonas dhakensis, an Increasingly Recognized Human Pathogen

    PubMed Central

    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. Prevalence and characteristics of Aeromonas species isolated from processed channel catfish.

    PubMed

    Wang, C; Silva, J L

    1999-01-01

    From August 1994 to May 1995, 238 channel catfish fillets collected from three processing plants in the Mississippi Delta at four time periods were tested for the presence of Aeromonas species. Identification of Aeromonas spp. was accomplished using an automated Vitek bioassay system with gram-negative and nonfermenter cards. Approximately 36.1% were positive for A. hydrophila, 35.7% for A. sobria, and 10.9% for A. caviae. All three Aeromonas spp. were found in all three processing plants, and the incidence of A. hydrophila contamination appeared to be higher in summer than other seasons. Eighty-six percent of the Aeromonas isolates were hemolytic on 5% sheep blood agar plates. Most isolates were susceptible to chloramphenicol, neomycin, streptomycin, and trimethoprim-sulfamethoxazole and resistant to ampicillin and bacitracin. Results suggest that Aeromonas spp. are prevalent in processed channel catfish, and most isolates are hemolytic and resistant to ampicillin and bacitracin. PMID:9921825

  14. Isolation and characterization of Aeromonas from seafoods in Taipei.

    PubMed

    Yaun, S S; Lin, L P

    1993-05-01

    A total of 124 fresh seafoods and 158 processed seafoods collected from the retail markets and supermarkets in Taipei were tested for the contamination with motile Aeromonas spp. Of the fresh seafoods analyzed, 88% displayed the presence of Aeromonas. The isolation rates of various samples were as follows: 100%, freshwater fish; 95%, seawater fish; 78%, fish fillets; 84%, shrimp and crab of the crustacea group; 83%, bivalve shellfish and 84%, non-bivalve shellfish of the mollusca group, and 100%, seaweed. Of the 158 processed seafoods, 11% were contaminated by Aeromonas. The isolation rates were as follows: 0%, canned, dried, or frozen fresh seafood; 18%, salted seafood; 30%, fish cake; 7% vacuum-packaged fish cakes; 14%, frozen seafood dumplings; 8%, cooked seafoods. One hundred and eighty-three Aeromonas strains isolated in this survey were characterized to species level and tested for their ability to produce beta-hemolysin. Ninety-eight percent (98%) of the A. hydrophila produced beta-hemolysin on 5% blood agar, 94% of the A. sobria and 33% of the A. caviae produced beta-hemolysin. Thus it is likely that fresh seafoods are potentially significant sources of the virulent Aeromonas species and may play an important role in the epidemiology of Aeromonas-associated gastroenteritis. PMID:7995079

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

    PubMed

    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(2) cfu g(-1) to >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

  16. An evaluation of replacing fish meal with fermented soybean meal in the diet of Macrobrachium nipponense: Growth, nonspecific immunity, and resistance to Aeromonas hydrophila.

    PubMed

    Ding, Zhili; Zhang, Yixiang; Ye, Jinyun; Du, Zhenyu; Kong, Youqin

    2015-05-01

    Partial or complete replacement of fish meal (FM) with fermented soybean meal (FSM) was examined in Macrobrachium nipponense over an 8-week growth trial. Growth and immune characteristics were evaluated. Fermented soybean meal replaced 0 (FM, control), 25% (R25), 50% (R50), 75% (R75), or 100% of the FM (R100) in five isocaloric and isonitrogenous diets. Each diet was fed to juvenile prawns (mean weight, 0.103 ± 0.0009 g) twice daily to apparent satiation in five replicates. Weight gain and specific growth rate of M. nipponense were significantly higher in prawns fed the R25 diet than that of prawns fed the FM diet. No significant differences were observed among the other treatments. Total hemocyte count and hemolymph phagocytic activity decreased as the proportion of FSM increased. Total antioxidant activity competence and malondialdehyde level in the hepatopancreas were highest in prawns fed the R100 diet. mRNA levels of the antioxidant genes Cu-Zn superoxide dismutase and catalase, heat shock cognate protein 70, and heat shock protein 90 were significantly differentially regulated in the prawn hepatopancreas. In addition, percent mortality increased after challenge with live Aeromonas hydrophila. Percent mortality of prawns fed the R100 diet was significantly higher than that of prawns fed the FM and R25 diets. These findings demonstrate that (1) M. nipponense growth performance was not affected by including a high proportion of FSM in the diet, and the best growth performance was obtained when 25% of the FM was replaced with FSM; (2) nonspecific immunity was impaired when all of the FM was replaced with FSM. PMID:25707598

  17. Stability evaluation of reference genes for real-time PCR in zebrafish (Danio rerio) exposed to cadmium chloride and subsequently infected by bacteria Aeromonas hydrophila.

    PubMed

    Lang, Xingping; Wang, Lan; Zhang, Zuobing

    2016-01-01

    Environmental and occupational cadmium (Cd) toxicity is a global concern, and the model organism zebrafish is an ideal species to investigate Cd toxicity. Among various detecting techniques, quantitative real-time PCR (qPCR) is a sensitive and efficient tool. Stable reference genes are critical for relative qPCR analysis. However, accumulated evidence shows that conventional reference genes can vary significantly under different experimental setups. Here we evaluated the stability of eight candidate reference genes of zebrafish with or without exposure to different concentrations of Cd. The results showed that the best four suitable reference genes in the five selected organs were: (1) spleen: β-actin>gapdh>ef1α>rpl13α; (2) kidney: rplp2>rpl7>β-actin>ef1α; (3) liver: rpl7>rpl13α>β-actin>ef1α; (4) gills: rplp2>gapdh>rnf7>ef1α; (5) intestine: ef1α>rnf7>rplp2>rpl13α. Moreover, we further assessed the expression stability of the four reference genes for Cd immunotoxicology studies in zebrafish. The expression profiles showed that ef1α in spleen and kidney, rpl13a in liver and rplp2 in intestine were the most suitable reference genes at 12h and 9 days after the injection with Aeromonas hydrophila following Cd exposure. In gills, the expression of gapdh was more stable than ef1α after 9 days of bacteria challenge while ef1α showed a higher stability than gapdh at 12h after bacteria injection. In conclusion, this study has demonstrated that different tissues of zebrafish have different suitable reference genes after Cd exposure and the subsequently pathogenic insults for qPCR. It emphasized the importance of reference gene evaluation for studies using qPCR, in particular when investigations involve factors not explored previously. PMID:26675370

  18. Toll-like receptor 4 signaling pathway can be triggered by grass carp reovirus and Aeromonas hydrophila infection in rare minnow Gobiocypris rarus.

    PubMed

    Su, Jianguo; Yang, Chunrong; Xiong, Feng; Wang, Yaping; Zhu, Zuoyan

    2009-07-01

    Toll-like receptor 4 (TLR4) is critical for LPS recognition and cellular responses. It also recognizes some viral envelope proteins. Detection mostly results in the inflammation rather than specific antiviral responses. However, it's unclear in fish. In this report, a TLR4 gene (named as GrTLR4b) was cloned and characterized from rare minnow Gobiocypris rarus. The full length of GrTLR4b cDNA consists of 2766 nucleotides and encodes a polypeptide of 818 amino acids with an estimated molecular mass of 94,518Da and a predicted isoelectric point of 8.41. The predicted amino acid sequence comprises a signal peptide, six leucine-rich repeat (LRR) motifs, one leucine-rich repeat C-terminal (LRRCT) motif, followed by a transmembrane segment of 23 amino acids, and a cytoplasmic region of 167 amino acids containing one Toll--interleukin 1--receptor (TIR) motif. It's closely similar to the zebrafish (Danio rerio) TLR4b amino acid sequence with an identity of 77%. Quantitative RT-PCR analysis showed GrTLR4b mRNA was constitutive expression in gill, heart, intestine, kidney, liver, muscle and spleen tissues in healthy animals and up-regulated by viruses and bacteria. After being infected by grass carp reovirus or Aeromonas hydrophila, GrTLR4b expressions were up-regulated from 24h post-injection and lasted until the fish became moribund (P<0.05). These data implied that TLR4 signaling pathway could be activated by both viral and bacterial infection in rare minnow. PMID:19264133

  19. Tetrahymena: An Alternative Model Host for Evaluating Virulence of Aeromonas Strains

    PubMed Central

    Pang, Mao-Da; Lin, Xiao-Qin; Hu, Meng; Li, Jing; Lu, Cheng-Ping; Liu, Yong-Jie

    2012-01-01

    An easier assessment model would be helpful for high-throughput screening of Aeromonas virulence. The previous study indicated the potential of Tetrahymena as a permissive model to examine virulence of Aeromonas hydrophila. Here our aim was to assess virulence of Aeromonas spp. using two model hosts, a zebrafish assay and Tetrahymena-Aeromonas co-culture, and to examine whether data from the Tetrahymena thermophila model reflects infections in the well-established animal model. First, virulence of 39 Aeromonas strains was assessed by determining the 50% lethal dose (LD50) in zebrafish. LD50 values ranging from 1.3×102 to 3.0×107 indicated that these strains represent a high to moderate degree of virulence and could be useful to assess virulence in the Tetrahymena model. In Tetrahymena-Aeromonas co-culture, we evaluated the virulence of Aeromonas by detecting relative survival of Aeromonas and Tetrahymena. An Aeromonas isolate was considered virulent when its relative survival was greater than 60%, while the Aeromonas isolate was considered avirulent if its relative survival was below 40%. When relative survival of T. thermophila was lower than 40% after co-culture with an Aeromonas isolate, the bacterial strain was regarded as virulent. In contrast, the strain was classified as avirulent if relative survival of T. thermophila was greater than 50%. Encouragingly, data from the 39 Aeromonas strains showed good correlation in zebrafish and Tetrahymena-Aeromonas co-culture models. The results provide sufficient data to demonstrate that Tetrahymena can be a comparable alternative to zebrafish for determining the virulence of Aeromonas isolates. PMID:23145022

  20. Parenteral immunization of PLA/PLGA nanoparticle encapsulating outer membrane protein (Omp) from Aeromonas hydrophila: Evaluation of immunostimulatory action in Labeo rohita (rohu).

    PubMed

    Rauta, Pradipta Ranjan; Nayak, Bismita

    2015-05-01

    Advanced vaccine research approaches needs to explore on biodegradable nanoparticles (NPs) based vaccine carrier that can serve as antigen delivery systems as well as immuno-stimulatory action to induce both innate and adaptive immune response in fish. Immunogenicity of PLA and PLGA NPs encapsulating outer membrane protein (Omp) antigen of Aeromonas hydrophila were evaluated through intra-peritoneal injection in fish, Labeo rohita. Antigen loaded PLA-Omp (223.5 ± 13.19 nm) and PLGA-Omp (166.4 ± 21.23 nm) NPs were prepared using double emulsion method by efficiently encapsulating the antigen reaching the encapsulation efficiency 44 ± 4.58% and 59.33 ± 5.13% respectively. Our formulated PLA Omp and PLGA-Omp NPs were in nanometer range (<500 nm) and could be successfully endocyted in the body. Despite low antigen loading in PLA-Omp, it showed considerably slower antigen release in vitro than PLGA-Omp NPs. Other physical properties like zetapotential values and poly dispersity index (PDI) confirmed the stability as well as monodisperse nature of the formulated nanoparticles. The spherical and isolated nature of PLA-Omp and PLGA-Omp NPs were revealed by SEM analysis. Upon immunization of all antigenic formulations (PLA-Omp NP, PLGA-Omp NP, FIA-Omp, PLA NP, PLGA NP, PBS as control), significant higher bacterial agglutination titre and haemolytic activity were observed in case of PLA-Omp and PLGA-Omp immunized groups than rest groups at both 21 days and 42 days. The specific antibody response was significantly increased and persisted up to 42 days of post immunization by PLA-Omp, PLGA-Omp, FIA-Omp. PLA-Omp NPs showed better immune response (higher bacterial agglutination titre, haemolytic activity, specific antibody titre, higher percent survival upon A. hydrophila challenge) than PLGA-Omp in L. rohita confirming its better efficacy. Comparable antibody response of PLA-Omp and PLGA-Omp with FIA-Omp treated groups suggested that PLA and PLGA could be replacement for

  1. Effect of guava leaves on the growth performance and cytokine gene expression of Labeo rohita and its susceptibility to Aeromonas hydrophila infection.

    PubMed

    Giri, Sib Sankar; Sen, Shib Sankar; Chi, Cheng; Kim, Hyoun Joong; Yun, Saekil; Park, Se Chang; Sukumaran, V

    2015-10-01

    The present study aimed to evaluate the effects of Psidium guajava L. (guava) leaves on the growth and immune response of the fish species Labeo rohita and its susceptibility to Aeromonas hydrophila infection. Diets containing five different concentrations of guava leaves (0% [basal diet], 0.1% [G1], 0.5% [G2], 1% [G3], and 1.5% [G4]) were fed to fish (average weight: 11.1 g) for 60 days. Various growth and immune parameters were examined 60 days post-feeding. Fish were challenged with A. hydrophila at the end of the trial, and mortalities were recorded over 15 days post-infection. We found that growth parameters such as percent weight gain (657.61 ± 9.74) and specific growth rate (3.37 ± 0.021) were significantly higher in G2 group than in the control (P < 0.05). Among the immune parameters examined, lysozyme levels (79.5 ± 5.1 U mL(-1)), leukocyte phagocytic activity (52 ± 4.3%), and alternative complement pathway activity (ACP) (186.1 ± 8.3 U mL(-1)) were significantly high (P < 0.05) in G2 fed group; there was, however, no significant effect of guava leaves at any concentration on plasma IgM level. Of the cytokine-related genes examined, interleukin-1beta (IL-1β) and tumour necrosis factor-alpha (TNF-α) were up-regulated in the head-kidney, intestine, and hepatopancreas of fish fed experimental diets, and expression was significantly higher in G2 and G3 than in the control group. In contrast, gene expression of IL-10, transforming growth factor-beta (TGF-β), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and transcription factor nuclear factor-κB (NF-κB) were down-regulated in the treatment groups. Moreover, fish fed the G2 diet exhibited a significantly higher post-challenge survival rate (66.66%). Collectively, these results suggest that dietary supplementation with guava leaves (at 0.5% concentration) could promote growth performance and strengthen immunity of L. rohita. Guava leaves therefore represent a promising feed additive

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

    EPA Science Inventory

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

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

    PubMed

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Transcriptional profiles of multiple genes in the anterior kidney of channel catfish vaccinated with an attenuated Aeromonas hydrophila

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 22 uniquely expressed sequence tags (ESTs) were identified from channel catfish anterior kidney subtractive cDNA library at 12h post vaccination with an attenuated A. hydrophila (AL09-71 N+R). Of the 22 ESTs, six were confirmed to be significantly (P<0.05) induced by the vaccination. Of 8...

  6. Attenuation of a virulent Aeromonas hydrophila with novobiocin and pathogenic characterization of the novobiocin-resistant strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novobiocin-resistant strain AH11NOVO was obtained from a virulent A. hydrophila strain AH11P through selection of resistance to novobiocin. AH11NOVO was found to be avirulent to channel catfish (Ictalurus punctatus) whereas AH11P was virulent. When AH11NOVO vaccinated channel catfish were challeng...

  7. Attenuation of a virulent Aeromonas hydrophila with novobiocin and pathogenic characterization of the novobiocin-resistant strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novobiocin-resistant strain AH11NOVO was obtained from a virulent A. hydrophila strain AH11P through selection of resistance to novobiocin. AH11NOVO was found to be avirulent to channel catfish whereas AH11P was virulent. When AH11NOVO vaccinated channel catfish were challenged with AH11P at 14 da...

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

    PubMed

    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

  9. Interaction of Aeromonas Strains with Lactic Acid Bacteria via Caco-2 Cells

    PubMed Central

    Hatje, E.; Neuman, C.

    2014-01-01

    The genus Aeromonas includes some species that have now been identified as human pathogens of significant medical importance. We investigated the ability of 13 selected Aeromonas strains belonging to nine species isolated from clinical cases (n = 5), environmental waters (n = 5), and fish (n = 3) to adhere to and translocate Caco-2 cells in the absence and presence of two lactic acid bacteria (LAB), i.e., Lactobacillus acidophilus and Bifidobacterium breve. Aeromonas isolates were also assessed for their cytotoxicity, the presence of virulence genes, and hemolysin production. Among the clinical isolates, one strain of Aeromonas veronii biovar veronii and two strains of Aeromonas hydrophila carried cytotoxin (act), heat-labile toxin (alt), hemolysin (hlyA), and aerolysin (aerA) genes, were cytotoxic to Vero cells, produced hemolysin, and showed higher adherence to Caco-2 cells. In contrast, this was seen in only one environmental strain, a strain of A. veronii biovar sobria. When Aeromonas strains were coinoculated with LAB onto Caco-2 cells, their level of adhesion was reduced. However, their rate of translocation in the presence of LAB increased and was significantly (P < 0.05) higher among fish strains. We suggest that either the interaction between Aeromonas and LAB strains could have a detrimental effect on the Caco-2 cells, allowing the Aeromonas to translocate more readily, or the presence of the LAB stimulated the Aeromonas strains to produce more toxins and/or increase their translocation rate. PMID:24242240

  10. Aeromonas in Arab countries: 1995-2014.

    PubMed

    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

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

    PubMed

    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

  12. Optimisation of the protocol for detection of Aeromonas species in ready-to-eat salads, and its use to speciate isolates and establish their prevalence.

    PubMed

    Mattick, K L; Donovan, T J

    1998-12-01

    Aeromonas spp. are detected in more than 500 cases of gastrointestinal infection each year in England and Wales. This study aimed to identify their prevalence in ready-to-eat salads, which are a potential source of aeromonas infection. The protocol for isolation of mesophilic Aeromonas spp. from salads was optimised. Using the improved method, Aeromonas spp were isolated from 19 of 25 samples (25 g) of ready-to-eat salad products. Aeromonas organisms were counted, isolates were identified to species level, and the effect of pH on colonisation of salads was assessed. Aeromonas was present at high levels in six salads (> or = 100 cfu/g). The major species present in salads was Aeromonas caviae, but A.hydrophila and A.sobria, which have more pathogenic potential, were also isolated. It is hoped that this study will help to assess the risk to public health of aeromonas in salads. PMID:9854886

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

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

    PubMed

    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

  16. N-Acylhomoserine lactones involved in quorum sensing control the type VI secretion system, biofilm formation, protease production, and in vivo virulence in a clinical isolate of Aeromonas hydrophila

    PubMed Central

    Khajanchi, Bijay K.; Sha, Jian; Kozlova, Elena V.; Erova, Tatiana E.; Suarez, Giovanni; Sierra, Johanna C.; Popov, Vsevolod L.; Horneman, Amy J.; Chopra, Ashok K.

    2009-01-01

    In this study, we delineated the role of N-acylhomoserine lactone(s) (AHLs)-mediated quorum sensing (QS) in the virulence of diarrhoeal isolate SSU of Aeromonas hydrophila by generating a double knockout ΔahyRI mutant. Protease production was substantially reduced in the ΔahyRI mutant when compared with that in the wild-type (WT) strain. Importantly, based on Western blot analysis, the ΔahyRI mutant was unable to secrete type VI secretion system (T6SS)-associated effectors, namely haemolysin coregulated protein and the valine-glycine repeat family of proteins, while significant levels of these effectors were detected in the culture supernatant of the WT A. hydrophila. In contrast, the production and translocation of the type III secretion system (T3SS) effector AexU in human colonic epithelial cells were not affected when the ahyRI genes were deleted. Solid surface-associated biofilm formation was significantly reduced in the ΔahyRI mutant when compared with that in the WT strain, as determined by a crystal violet staining assay. Scanning electron microscopic observations revealed that the ΔahyRI mutant was also defective in the formation of structured biofilm, as it was less filamentous and produced a distinct exopolysaccharide on its surface when compared with the structured biofilm produced by the WT strain. These effects of AhyRI could be complemented either by expressing the ahyRI genes in trans or by the exogeneous addition of AHLs to the ΔahyRI/ahyR+ complemented strain. In a mouse lethality experiment, 50 % attenuation was observed when we deleted the ahyRI genes from the parental strain of A. hydrophila. Together, our data suggest that AHL-mediated QS modulates the virulence of A. hydrophila SSU by regulating the T6SS, metalloprotease production and biofilm formation. PMID:19729404

  17. Optimisation and standardisation of functional immune assays for striped catfish (Pangasianodon hypophthalmus) to compare their immune response to live and heat killed Aeromonas hydrophila as models of infection and vaccination.

    PubMed

    Sirimanapong, Wanna; Thompson, Kim D; Kledmanee, Kan; Thaijongrak, Prawporn; Collet, Bertrand; Ooi, Ei Lin; Adams, Alexandra

    2014-10-01

    Aquaculture production of Pangasianodon hypophthalmus is growing rapidly in South East Asia, especially in Vietnam. As it is a relatively new aquaculture species there are few reports evaluating its immune response to pathogens. Thus, functional assays for P. hypophthalmus were optimised to evaluate both innate and adaptive immune responses, and were then used to examine immune response following stimulation with live and heat-killed Aeromonas hydrophila. These were used as models of infection and vaccination, respectively. Four treatment groups were used, including a control group, a group injected intraperitonally (IP) with adjuvant only, a group injected with heat-killed A. hydrophila (1 × 10(9) cfu ml(-1) mixed with adjuvant), and a group injected with a subclinical dose of live A. hydrophila. Samples were collected at 0, 1, 3, 7, 14 and 21 days post-injection (d.p.i.) to assess their immune response. The results indicated that challenge with live or dead bacteria stimulated the immune response in P. hypophthalmus significantly above the levels observed in control groups with respect to specific antibody titre, plasma lysozyme and peroxidase activity, and phagocytosis by head kidney macrophages at 7 or/and 14 d.p.i. At 21 d.p.i., total and specific antibody (IgM) levels and plasma lysozyme activity in fish injected with either live or dead A. hydrophila were significantly different to the control groups. Differential immune responses were observed between fish injected with either live or dead bacteria, with live A. hydrophila significantly stimulating an increase in WBC counts and plasma peroxidase activity at 3 d.p.i., with the greatest increase in WBC counts noted at 21 d.p.i. and in phagocytosis at 14 d.p.i. By 21 d.p.i. only the macrophages from fish injected with dead A. hydrophila showed significantly stimulation in their respiratory burst activity. This study provides basic information on the immune response in pangasius catfish that can be useful in

  18. Necrotizing fasciitis caused by Aeromonas caviae

    PubMed Central

    Kumar, Simit; Mukhopadhyay, Prabir; Chatterjee, Mitali; Bandyopadhyay, Manas K; Bandyopadhyay, Maitreyi; Ghosh, Tapashi; Samaddar, Debopriyo

    2012-01-01

    Aeromonads are rarely associated with human intestinal and extra-intestinal diseases and syndromes, ranging from relatively mild illnesses such as acute gastroenteritis to life-threatening conditions, including septicemia, necrotizing fasciitis, and myonecrosis. Among the aeromonas species known to cause human infection, Aeromonas caviae has been associated with septicemia and only one reported case of human soft tissue infection. Most of the infections due to aeromonas occur in immunocompromised patients. Herein we describe a successfully treated case of post-traumatic skin and soft-tissue infections due to A. caviae in an otherwise immunocompetent individual. PMID:23826556

  19. Role of flm Locus in Mesophilic Aeromonas Species Adherence

    PubMed Central

    Gryllos, Ioannis; Shaw, Jonathan G.; Gavín, Rosalina; Merino, Susana; Tomás, Juan M.

    2001-01-01

    The adherence mechanism of Aeromonas caviae Sch3N to HEp-2 cells was initially investigated through four mini-Tn5 mutants that showed a 10-fold decrease in adherence. These mutants lost motility, flagella, and their lipopolysaccharide (LPS) O antigen (O-Ag). Three genes, flmB-neuA-flmD, were found to be interrupted by the transposon insertions; additionally, two other genes, one lying upstream (flmA) and one downstream (neuB), were found to be clustered in the same operon. While the flmA and flmB genes were present in all mesophilic Aeromonas spp. (A. hydrophila, A. caviae, A. veronii bv. veronii, and A. veronii bv. sobria) tested, this was not the case for the neuA-flmD-neuB genes. Construction and characterization of flmB insertion mutants in five other mesophilic Aeromonas strains revealed the loss of motility, flagella, and adherence but did not alter the LPS composition of these strains. Taking the above findings into consideration, we conclude (i) that flagella and possibly the LPS O-Ag are involved in the adherence of the mesophilic Aeromonas to human epithelial cells; (ii) flmA and flmB are genes widely distributed in the mesophilic Aeromonas and are involved in flagella assembly, and thus adherence; and (iii) in A. caviae Sch3N the flmA and flmB genes are found in a putative operon together with neuA, flmD, and neuB and are involved in LPS O-Ag biosynthesis and probably have a role in flagellum assembly. PMID:11119490

  20. The incidence of virulence factors in mesophilic Aeromonas species isolated from farm animals and their environment.

    PubMed Central

    Gray, S. J.; Stickler, D. J.; Bryant, T. N.

    1990-01-01

    Sixty-one isolates of Aeromonas spp. from the faeces of pigs, cows and a variety of associated environmental sources were examined for the characteristics that are reputed to have roles in pathogenicity. Most isolates of Aeromonas hydrophila were cytotoxic (96.4%) and were capable of producing cell elongation factor (75%) and haemagglutinins (67.9%). In contrast few of the Aeromonas caviae isolates produced these three markers (13.6%, 27.3% and 36.4% respectively). In general, Aeromonas sobria occupied an intermediate position (36.4%, 27.3% and 54.5%), but they did produce the highest mean invasion index for HEp-2 cells. Statistical analysis revealed significant associations between the carriage of these factors and it was clear that many isolates of aeromonads from water and animals possessed the full battery of putative virulence factors. PMID:2209733

  1. DNA adenine methyltransferase (Dam) controls the expression of the cytotoxic enterotoxin (act) gene of Aeromonas hydrophila via tRNA modifying enzyme-glucose-inhibited division protein (GidA)

    PubMed Central

    Erova, Tatiana E.; Kosykh, Valeri G.; Sha, Jian; Chopra, Ashok K.

    2013-01-01

    Aeromonas hydrophila is both a human and animal pathogen, and the cytotoxic enterotoxin (Act) is a crucial virulence factor of this bacterium because of its associated hemolytic, cytotoxic, and enterotoxic activities. Previously, to define the role of some regulatory genes in modulating Act production, we showed that deletion of a glucose-inhibited division gene (gidA) encoding tRNA methylase reduced Act levels, while overproduction of DNA adenine methyltransferase (Dam) led to a concomitant increase in Act-associated biological activities of a diarrheal isolate SSU of A. hydrophila. Importantly, there are multiple GATC binding sites for Dam within an upstream sequence of the gidA gene and one such target site in the act gene upstream region. We showed the dam gene to be essential for the viability of A. hydrophila SSU, and, therefore, to better understand the interaction of the encoding genes, Dam and GidA, in act gene regulation, we constructed a gidA in-frame deletion mutant of Escherichia coli GM28 (dam+) and GM33 (Δdam) strains. We then tested the expressional activity of the act and gidA genes by using a promoterless pGlow-TOPO vector containing a reporter green fluorescent protein (GFP). Our data indicated that in GidA+ strains of E. coli, constitutive methylation of the GATC site(s) by Dam negatively regulated act and gidA gene expression as measured by GFP production. However, in the ΔgidA strains, irrespective of the presence or absence of constitutively active Dam, we did not observe any alteration in the expression of the act gene signifying the role of GidA in positively regulating Act production. To determine the exact mechanism of how Dam and GidA influence Act, a real-time quantitative PCR (RT-qPCR) assay was performed. The analysis indicated an increase in gidA and act gene expression in the A. hydrophila Dam-overproducing strain, and these data matched with Act production in the E. coli GM28 strain. Thus, the extent of DNA methylation caused by

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

    PubMed

    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

  3. Aeromonas flagella and colonisation mechanisms.

    PubMed

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

    2014-01-01

    Aeromonas species are inhabitants of aquatic environments and are able to cause disease in humans and fish among other animals. In aquaculture, they are responsible for the economically important diseases of furunculosis and motile Aeromonas septicaemia (MAS). Whereas gastroenteritis and wound infections are the major human diseases associated with the genus. As they inhabit and survive in diverse environments, aeromonads possess a wide range of colonisation factors. The motile species are able to swim in liquid environments through the action of a single polar flagellum, the flagellin subunits of which are glycosylated; although essential for function the biological role of glycan addition is yet to be determined. Approximately 60% of aeromonads possess a second lateral flagella system that is expressed in viscous environments for swarming over surfaces; both flagellar systems have been shown to be important in the initial colonisation of surfaces. Subsequently, other non-flagellar colonisation factors are employed; these can be both filamentous and non-filamentous. The aeromonads possess a number of fimbrial systems with the bundle-forming MSHA type IV pilus system, having a major role in human cell adherence. Furthermore, a series of outer-membrane proteins have also been implicated in the aeromonad adhesion process. A number of strains are also capable of cell invasion and that maybe linked with the more invasive diseases of bacteraemia or wound infections. These strains employ cell surface factors that allow the colonisation of these niches that protect them from the host's immune system such as S-layers, capsules or particular lipopolysaccharides. PMID:25476767

  4. VIRULENCE RELATIONSHIPS OF AEROMONAS SPECIES AS DETERMINED BY EXPOSURES TO IMMUNOCOMPROMISED MICE

    EPA Science Inventory

    Our laboratory is currently determining the virulence of opportunistic pathogens reported in treated drinking water and drinking water sources. Aeromonas hydrophila is currently on the EPA's Contaminant Candidate List (CCL) and is an example of those types of bacteria that conta...

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

    EPA Science Inventory

    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...

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

    EPA Science Inventory

    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...

  7. Draft Genome Sequence of Aeromonas sp. Strain EERV15.

    PubMed

    Ehsani, Elham; Barrantes, Israel; Vandermaesen, Johanna; Geffers, Robert; Jarek, Michael; Boon, Nico; Springael, Dirk; Pieper, Dietmar H; Vilchez-Vargas, Ramiro

    2016-01-01

    We report here the draft genome sequence of Aeromonas sp. strain EERV15 isolated from sand filter. The organism most closely related to Aeromonas sp. EERV15 is Aeromonas veronii B565, with an average 83% amino acid sequence similarity of putatively encoded protein open reading frames. PMID:27540061

  8. Draft Genome Sequence of Aeromonas sp. Strain EERV15

    PubMed Central

    Ehsani, Elham; Barrantes, Israel; Vandermaesen, Johanna; Geffers, Robert; Jarek, Michael; Boon, Nico; Springael, Dirk; Pieper, Dietmar H.

    2016-01-01

    We report here the draft genome sequence of Aeromonas sp. strain EERV15 isolated from sand filter. The organism most closely related to Aeromonas sp. EERV15 is Aeromonas veronii B565, with an average 83% amino acid sequence similarity of putatively encoded protein open reading frames. PMID:27540061

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

    PubMed

    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

  10. Aeromonas jandaei and Aeromonas veronii dual infection of a human wound following aquatic exposure.

    PubMed Central

    Joseph, S W; Carnahan, A M; Brayton, P R; Fanning, G R; Almazan, R; Drabick, C; Trudo, E W; Colwell, R R

    1991-01-01

    Exudate removed from an infection that developed below the left eye of a 10-year-old male following a previously inflicted wound after aquatic exposure was cultured and revealed two different Aeromonas spp. Further characterization showed that one strain was phenotypically identical to Aeromonas veronii, while the other strain was confirmed by DNA hybridization analysis to be Aeromonas jandaei sp. nov. This is the first report of these more recently described aeromonads, thus far rarely reported from clinical disease, occurring simultaneously in a human infection. PMID:2037674

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

    PubMed

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

    2015-07-01

    Aeromonads are ubiquitous foodborne pathogens with a global distribution. Animal-origin foods and contaminated animals are the main sources of Aeromonas infection to humans. So far little is known about the occurrence of Aeromonas spp. in food-producing animals in India. The present study was conducted to determine the prevalence and seroprevalence of Aeromonas species from 50 each of meat, blood, and sera samples collected from cattle, buffaloes, goats, and pigs slaughtered in and around Nagpur, Central India. Alkaline peptone water and ampicillin dextrin agar were used to isolate Aeromonas spp. An indirect enzyme-linked immunosorbent assay (ELISA) was standardized by use of whole-cell antigen (WC) and outer membrane protein (OMP) of Aeromonas hydrophila (MTCC 646). Aeromonads were isolated from 44 (22%) of the meat samples, and 1 (0.5%) from the blood samples. Seroprevalence by indirect ELISA-based WC antigen was estimated as 68% in cattle, 44% in buffaloes, 60% in goats, and 30% in pigs. OMP-based ELISA yielded a seroprevalence of 56%, 48%, 52%, and 22% in cattle, buffaloes, goats, and pigs, respectively. The results revealed that OMP-based ELISA and WC-based ELISA were in agreement with one another. Isolation along with high seropositivity demonstrates the presence of foodborne Aeromonas spp. in the Nagpur city of Central India. PMID:25946095

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

    PubMed

    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

  13. Congo red uptake by motile Aeromonas species.

    PubMed

    Statner, B; George, W L

    1987-05-01

    Virulence of several species of enteropathogenic bacteria has been correlated with the ability of isolates to take up the dye Congo red. To determine whether Congo red uptake might be a useful marker for virulence of motile Aeromonas species, we examined 50 strains of diverse clinical origin on a medium containing 50 micrograms of Congo red per ml. All of the strains took up the dye to various degrees. For most strains, uptake was greatest at 37 degrees C and least at 22 degrees C. Production of acetyl methyl carbinol (Voges-Proskauer test) or lysine decarboxylase has been reported by some investigators to be a virulence marker for Aeromonas species. Congo red uptake did not correlate with either acetyl methyl carbinol or lysine decarboxylase production in our study. These data suggest that Congo red uptake may not be a useful marker for virulence of motile Aeromonas species. PMID:3584422

  14. Antimicrobial resistance in food and clinical Aeromonas isolates.

    PubMed

    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

  15. Evaluation of different assay systems for identification of environmental Aeromonas strains.

    PubMed

    Toranzo, A E; Santos, Y; Nieto, T P; Barja, J L

    1986-03-01

    Important biochemical reactions in conventional tests were compared with counterpart reactions in two multiple test systems, API-20E (Analytab Products, Plainview, N.Y.) and Aeromonas hydrophila medium, to evaluate their accuracy for the identification of motile Aeromonas spp. isolated from fish. In a total of 49 Aeromonas spp. isolates and 10 A. hydrophila reference strains, false-negative or -positive reactions were detected in the Voges-Proskauer test, indole production, gelatinase activity, production of gas, fermentation of arabinose, and lysine decarboxylase reaction. A good correlation was found, among the three identification systems, for the fermentation of mannitol and inositol as well as for the arginine dihydrolase and ornithine decarboxylase tests. The failure of A. hydrophila medium in the detection of gas indicates that this medium is not entirely suitable for defining aerogenic or anaerogenic strains. From the results of the present study, we consider that of the identification method and taxonomic scheme to be adopted for environmental Aeromonas spp. must be standardized. PMID:16347025

  16. Dietary myo-inositol modulates immunity through antioxidant activity and the Nrf2 and E2F4/cyclin signalling factors in the head kidney and spleen following infection of juvenile fish with Aeromonas hydrophila.

    PubMed

    Jiang, Wei-Dan; Hu, Kai; Liu, Yang; Jiang, Jun; Wu, Pei; Zhao, Juan; Zhang, Yong-An; Zhou, Xiao-Qiu; Feng, Lin

    2016-02-01

    This study was conducted to investigate the effects of the dietary vitamin myo-inositol (MI), on the immunity and structural integrity of the head kidney and spleen following infection of fish with the major freshwater pathogen bacterial Aeromonas hydrophila. The results demonstrated for the first time that MI deficiency depressed the lysozyme and acid phosphatase (ACP) activities and the complement 3 (C3) and C4 contents in the head kidney and spleen compared with the optimal MI levels, indicating that MI deficiency decreased the immunity of these important fish immune organs. The depression in immunity due to MI deficiency was partially related to oxidative damage [indicated by increases in the malondialdehyde (MDA) and protein carbonyl (PC) contents] that was in turn partially due to the decreased glutathione (GSH) content and the disturbances in antioxidant enzyme activities [total superoxide dismutase (T-SOD), CuZnSOD, MnSOD, catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR)]. MI deficiency inhibited the antioxidant-related gene transcription [CuZnSOD, MnSOD, CAT, GPx1a, GR and NF-E2-related factor 2 (Nrf2)] in the head kidney and spleen following infection of the fish with A. hydrophila. The oxidative damage due to MI deficiency also resulted in the inhibition of proliferation-associated signalling (cyclin D1, cyclin A, cyclin E and E2F4). Thus, MI deficiency partially inhibited damage repair. Excessive MI exhibited negative effects that were similar to MI deficiency, whereas the optimal MI content reversed those indicators. These observations indicated that an MI deficiency or excess could cause depression of the immune system that might be partially related to oxidative damage, antioxidant disturbances, and the inhibition of the proliferation-associated signalling in the head kidney and spleen following infection of fish with A. hydrophila. Finally, the optimal MI levels were 660.7 (based on ACP) and 736.8 mg kg(-1) diet (based

  17. Severe sepsis due to Aeromonas aquariorum in a patient with liver cirrhosis.

    PubMed

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

    2013-01-01

    Thus far, Aeromonas aquariorum infection has been unrecorded in Korea. Herein, we report a fatal case of A. aquariorum infection in a 77-year-old male patient with liver cirrhosis. The bacterium isolated from a blood culture was initially mistaken as Aeromonas hydrophila using the Vitek2 identification system. In spite of intravenous ceftriaxone therapy, the patient was exacerbated by multiple organ dysfunction. By 4 days after admission, there was no hope for treatment or remission of symptoms and the patient was discharged. In the detailed microbiological investigations, the bacterium was identified as A. aquariorum harboring the act and alt genes, which encode cytotoxic and cytotonic enterotoxins. PMID:24270141

  18. Aeromonas spp.: An Emerging Nosocomial Pathogen.

    PubMed

    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

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

    PubMed

    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

  20. Aeromonas spp.: ubiquitous or specialized bugs?

    PubMed

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

    2014-04-01

    The genus Aeromonas comprises ubiquitous bacteria that are known to play several roles in the environment. These bacteria were first described as fish pathogens, but their presence was documented in other reservoirs, such as animals and humans. Today, these bacteria are described as emerging pathogens, but their effective role in human pathogenicity is still controversial. In addition, their taxonomy is heavily debated, as species distinction is often difficult to achieve. To study the interspecies relationships and to investigate their connection with the environment, a multilocus sequence typing scheme previously developed for Aeromonas spp. was applied to 258 strains, and the genetic data were analysed by population software. Sampling was a fundamental step, including several of the main sources of Aeromonas: fish, food products and human cases of disease. The objective was to characterize the isolates and to find potential associations among them according to the following: species, sharing of virulence factors, source and adaptation to a specific habitat. The strains were characterized and demonstrated exceptionally high nucleotide variability in the Aeromonas genus. Among the sampled sources, different species distributions were found, highlighting the occurrence of adaptation processes towards specific habitats. PMID:23919504

  1. Aeromonas spp.: An Emerging Nosocomial Pathogen

    PubMed Central

    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

  2. Analysis of immune-related ESTs and differential expression analysis of few important genes in lines of rohu (Labeo rohita) selected for resistance and susceptibility to Aeromonas hydrophila infection.

    PubMed

    Das, Sweta; Chhottaray, Chiranjibi; Das Mahapatra, Kanta; Saha, Jatindra Nath; Baranski, Matthew; Robinson, Nicholas; Sahoo, P K

    2014-11-01

    A total of 137,629 contigs generated via de novo transcriptome assembly from resistant and susceptible lines of rohu (first generation) raised against aeromoniasis were further analyzed in terms of defence-related genes. Out of 1,939 contigs showing homology to genes involved in immune processes, 1,866 were further categorised into different functional subgroups. Comparative analysis revealed five genes for the first time in any carp species out of which apolipoprotein h, septin 4 isoform 3 and septin isoform cra_c were identified for the first time in fish. Differential expression analysis of ten genes viz., heat shock proteins (Hsps) (Hsp30, Hsp70 and Hsp90), serum lectin isoform 1 (SLI1), linker histone H1M (LHH1M), NAD(P)H quinone 1 (NQO1), zona pellucida 2 (ZP2) and three unknown genes that were highly up-expressed in first generation resistant line fish from mRNA-seq coverage data, was carried out using susceptible and resistant individuals of the second generation selected populations in eight different tissues viz. liver, kidney, intestine, gill, brain, spleen, skin and muscle using qPCR. Significant up-regulation in Hsp90, NQO1, C_116914 and C_22454 in specific tissues of resistant line and variable expression in Hsp30 and LHH1M genes in different tissues of both lines were noticed. The expression of Hsp70 was lower in many tissues of the resistant line than in susceptible line rohu. The expression of ZP2, SLI1 and C_94589 genes was not significantly different in terms of fold difference between the two lines. Differentially expressed genes need further characterisation to explore their role in resistance to Aeromonas hydrophila infection in rohu. PMID:25081649

  3. Structure of AscE and induced burial regions in AscE and AscG upon formation of the chaperone needle-subunit complex of type III secretion system in Aeromonas hydrophila

    PubMed Central

    Tan, Yih Wan; Yu, Hong Bing; Leung, Ka Yin; Sivaraman, J.; Mok, Yu-Keung

    2008-01-01

    In the type III secretion system (T3SS) of Aeromonas hydrophila, the putative needle complex subunit AscF requires both putative chaperones AscE and AscG for formation of a ternary complex to avoid premature assembly. Here we report the crystal structure of AscE at 2.7 Å resolution and the mapping of buried regions of AscE, AscG, and AscF in the AscEG and AscEFG complexes using limited protease digestion. The dimeric AscE is comprised of two helix–turn–helix monomers packed in an antiparallel fashion. The N-terminal 13 residues of AscE are buried only upon binding with AscG, but this region is found to be nonessential for the interaction. AscE functions as a monomer and can be coexpressed with AscG or with both AscG and AscF to form soluble complexes. The AscE binding region of AscG in the AscEG complex is identified to be within the N-terminal 61 residues of AscG. The exposed C-terminal substrate-binding region of AscG in the AscEG complex is induced to be buried only upon binding to AscF. However, the N-terminal 52 residues of AscF remain exposed even in the ternary AscEFG complex. On the other hand, the 35-residue C-terminal region of AscF in the complex is resistant to protease digestion in the AscEFG complex. Site-directed mutagenesis showed that two C-terminal hydrophobic residues, Ile83 and Leu84, of AscF are essential for chaperone binding. PMID:18662905

  4. Structure of AscE and Induced Burial Regions in AscE and AscG upon Formation of the Chaperone Needle-subunit Complex of Type III Secretion System in Aeromonas Hydrophila

    SciTech Connect

    Tan, Y.; Yu, H; Leung, K; Sivaraman, J; Mok, Y

    2008-01-01

    In the type III secretion system (T3SS) of Aeromonas hydrophila, the putative needle complex subunit AscF requires both putative chaperones AscE and AscG for formation of a ternary complex to avoid premature assembly. Here we report the crystal structure of AscE at 2.7 A resolution and the mapping of buried regions of AscE, AscG, and AscF in the AscEG and AscEFG complexes using limited protease digestion. The dimeric AscE is comprised of two helix-turn-helix monomers packed in an antiparallel fashion. The N-terminal 13 residues of AscE are buried only upon binding with AscG, but this region is found to be nonessential for the interaction. AscE functions as a monomer and can be coexpressed with AscG or with both AscG and AscF to form soluble complexes. The AscE binding region of AscG in the AscEG complex is identified to be within the N-terminal 61 residues of AscG. The exposed C-terminal substrate-binding region of AscG in the AscEG complex is induced to be buried only upon binding to AscF. However, the N-terminal 52 residues of AscF remain exposed even in the ternary AscEFG complex. On the other hand, the 35-residue C-terminal region of AscF in the complex is resistant to protease digestion in the AscEFG complex. Site-directed mutagenesis showed that two C-terminal hydrophobic residues, Ile83 and Leu84, of AscF are essential for chaperone binding.

  5. Molecular Characterization and Expression Analyses of the Complement Component C8α, C8β and C9 Genes in Yellow Catfish (Pelteobagrus fulvidraco) after the Aeromonas hydrophila Challenge.

    PubMed

    Zheng, Huan; Ji, Wei; Zhang, Gui-Rong; Zhang, Xiao-Ting; Shi, Ze-Chao; Wei, Kai-Jian; Yang, Rui-Bin; Gardner, Jonathan P A

    2016-01-01

    The complement components C8α, C8β and C9 have important roles in the innate immune system against invading microorganisms. Partial cDNA sequences of the Pf_C8α, Pf_C8β and Pf_C9 genes (Pf: abbreviation of Pelteobagrus fulvidraco) were cloned from yellow catfish. The Pf_C8α, Pf_C8β and Pf_C9 genes showed the greatest amino acid similarity to C8α (54%) and C8β (62%) of zebrafish and to C9 (52%) of grass carp, respectively. Ontogenetic expression analyses using real-time quantitative PCR suggested that the three genes may play crucial roles during embryonic and early larval development. The mRNA expressions of the three genes were all at the highest levels in liver tissue, and at lower or much lower levels in 16 other tissues, demonstrating that the liver is the primary site for the protein synthesis of Pf_C8α, Pf_C8β and Pf_C9. Injection of Aeromonas hydrophila led to up-regulation of the three genes in the spleen, head kidney, kidney, liver and blood tissues, indicating that the three genes may contribute to the host's defense against invading pathogenic microbes. An increased understanding of the functions of the Pf_C8α, Pf_C8β and Pf_C9 genes in the innate immunity of yellow catfish will help enhance production of this valuable freshwater species. PMID:27005612

  6. Molecular Characterization and Expression Analyses of the Complement Component C8α, C8β and C9 Genes in Yellow Catfish (Pelteobagrus fulvidraco) after the Aeromonas hydrophila Challenge

    PubMed Central

    Zheng, Huan; Ji, Wei; Zhang, Gui-Rong; Zhang, Xiao-Ting; Shi, Ze-Chao; Wei, Kai-Jian; Yang, Rui-Bin; Gardner, Jonathan P. A.

    2016-01-01

    The complement components C8α, C8β and C9 have important roles in the innate immune system against invading microorganisms. Partial cDNA sequences of the Pf_C8α, Pf_C8β and Pf_C9 genes (Pf: abbreviation of Pelteobagrus fulvidraco) were cloned from yellow catfish. The Pf_C8α, Pf_C8β and Pf_C9 genes showed the greatest amino acid similarity to C8α (54%) and C8β (62%) of zebrafish and to C9 (52%) of grass carp, respectively. Ontogenetic expression analyses using real-time quantitative PCR suggested that the three genes may play crucial roles during embryonic and early larval development. The mRNA expressions of the three genes were all at the highest levels in liver tissue, and at lower or much lower levels in 16 other tissues, demonstrating that the liver is the primary site for the protein synthesis of Pf_C8α, Pf_C8β and Pf_C9. Injection of Aeromonas hydrophila led to up-regulation of the three genes in the spleen, head kidney, kidney, liver and blood tissues, indicating that the three genes may contribute to the host’s defense against invading pathogenic microbes. An increased understanding of the functions of the Pf_C8α, Pf_C8β and Pf_C9 genes in the innate immunity of yellow catfish will help enhance production of this valuable freshwater species. PMID:27005612

  7. Influence of food system conditions on N-acyl-L-homoserine lactones production by Aeromonas spp.

    PubMed

    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

  8. Biochemical and molecular characterization of the novobiocin and rifampicin resistant Aeromonas hydrophila vaccine strain AL09-71 N+R compared to its virulent parent strain AL90-71

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the fitness cost of novobiocin- and rifampicin- resistance in an attenuated Aeromonas hydrophiila vaccine strain AL09-71 N+R compared to its virulent parent strain AL09-71, colony size, cell size, cell proliferation rate, chemotactic response, and the ability to invade catfish gill cel...

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

    PubMed

    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

  10. [Resistance to antimicrobial agents, hemolytic activity and plasmids in Aeromonas species].

    PubMed

    Morita, K; Watanabe, N; Kanamori, M

    1990-06-01

    A total of 174 Aeromonas isolates consisting of 100 strains from patients with diarrhea being mainly overseas travellers nd healthy subjects, and 74 strains from environmental sources including foods, fish, fresh water, sea water and river soil collected in the area of Tokyo Metropolis and Kanagawa Prefecture was examined for the antimicrobial resistance, presence of plasmids and hemolytic activity. Almost all the isolates (99.4%) were resistant to aminobenzyl penicillin. The isolation frequency of chloramphenicol- or tetracycline-resistant strain was low. Most environmental isolates of A. hydrophila were resistant to multiple antimicrobial agents. Thirty-seven percent of environmental isolates and 39% of human fecal ones carried plasmids. In environmental isolates, seven A. hydrophila and three A. sobria strains carried 63- to 150-kilobase pair (kb) conjugative R plasmids. Two A. hydrophila strains from both the healthy subject and domestic case with diarrhea carried 58- to 90-kb conjugative R plasmids, respectively. None of the isolates from the feces of overseas traveller's diarrhea carried the plasmid. Irrespective of the sources. A. hydrophila showed the highest hemolytic activity among three Aeromonas species. Eighty percent or more of A. hydrophila isolates were of hemolysin positive. The hemolytic titer of A. hydrophila strains from human feces was higher than that of the strains from environmental sources. PMID:2401817

  11. The risk to public health of aeromonas in ready-to-eat salad products.

    PubMed

    Mattick, K L; Donovan, T J

    1998-12-01

    Mesophilic Aeromonas spp. are isolated regularly from cases of gastrointestinal infection and have markers indicative of enteropathogenicity. Is aeromonas, which is present in a large proportion of ready-to-eat salads, actually a gastrointestinal pathogen? Isolates of mesophilic aeromonas from salads were characterised in terms of their ability to grow at refrigeration temperatures over the given shelf life and by the presence of markers of potential virulence. The major phenospecies present in salads, A.caviae, showed little enteropathogenic potential. Thirty-five per cent of aeromonas salad isolates are A.hydrophila or A.sobria, however, and all isolates tested had at least one marker of enteropathogenicity, including cytotoxin and haemolysin production, adherence to epithelial cells, and resistance to certain antibiotics Despite the presence of markers of enteropathogencity, the lack of epidemiological evidence of a link between infectious intestinal disease and the consumption of salads suggests that their contamination with aeromonas does not pose a significant risk to health in immunocompetent adults. PMID:9854887

  12. Aeromonas trota sp. nov., an ampicillin-susceptible species isolated from clinical specimens.

    PubMed

    Carnahan, A M; Chakraborty, T; Fanning, G R; Verma, D; Ali, A; Janda, J M; Joseph, S W

    1991-06-01

    Previous DNA hybridization studies established 12 Aeromonas genospecies, from which nine phenotypic species have been proposed: Aeromonas hydrophila, A. sobria, A. caviae, A. media, A. veronii, A. schubertii, A. salmonicida, A. eucrenophila, and A. jandaei. We have delineated a new Aeromonas genospecies, A. trota, on the basis of 13 strains isolated primarily from fecal specimens from southern and southeastern Asia. All strains were highly related to the proposed type strain, AH2 (ATCC 49657T): 51 to 100% (60 degrees C) and 49 to 99% (75 degrees C), with 0.2 to 2.2 divergence. AH2 was only 16 to 41% (60 degrees C) related to all other Aeromonas type strains and DNA group definition strains. The unique profile of A. trota includes negative reactions for esculin hydrolysis, arabinose fermentation, and the Voges-Proskauer test, positive reactions for cellobiose fermentation, lysine decarboxylation, and citrate utilization, and susceptibility to ampicillin, as determined by the broth microdilution MIC method and the Bauer-Kirby disk diffusion method (10 micrograms). Nine of the A. trota strains were from a single study of 165 geographically diverse aeromonads. This finding questions the efficacy of screening fecal specimens for Aeromonas spp. with ampicillin-containing media and suggests a previously unrecognized prevalence of this new species. PMID:1864939

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

    PubMed

    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

  14. G-protein coupled receptor 18 (GPR18) in channel catfish: Expression analysis and efficacy as immunostimulant against Aeromonas hydrophila infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were: 1) to determine the transcriptional profiles of G-protein coupled receptor 18 (GPR18) in channel catfish after infection with A. hydrophila compared to that in healthy catfish; 2) to determine whether over-expression of GPR18 in catfish gill cells will offer protec...

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

    PubMed Central

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

    2012-01-01

    Aeromonas species are ubiquitous bacteria in terrestrial and aquatic milieus. They are becoming renowned as enteric pathogens of serious public health concern as they acquire a number of virulence determinants that are linked with human diseases, such as gastroenteritis, soft-tissue, muscle infections, septicemia, and skin diseases. Proper sanitary procedures are essential in the prevention of the spread of Aeromonas infections. Oral fluid electrolyte substitution is employed in the prevention of dehydration, and broad-spectrum antibiotics are used in severe Aeromonas outbreaks. This review presents an overview of emerging Aeromonas infections and proposes the need for actions necessary for establishing adequate prevention measures against the infections. PMID:22701365

  16. Medicinal leech therapy and Aeromonas spp. infection.

    PubMed

    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

  17. Enterotoxin production in relation to taxonomic grouping and source of isolation of Aeromonas species.

    PubMed

    Turnbull, P C; Lee, J V; Miliotis, M D; Van de Walle, S; Koornhof, H J; Jeffery, L; Bryant, T N

    1984-02-01

    A total of 19 of 20 (95%) strains of Aeromonas hydrophila biovar hydrophila and 16 of 17 (94%) strains of Aeromonas sobria isolated from a variety of clinical and environmental sources were found to be enterotoxin positive. Only 2 of 18 (11%) A. hydrophila biovar anaerogenes and 2 of 13 (15%) unidentified Aeromonas strains from a similar variety of sources produced enterotoxin. No association was apparent between the source of isolation, in particular diarrheal stools, and enterotoxigenicity; 41% of the isolates from diarrheal stools were enterotoxin negative. A strong correlation was noted between ability to produce enterotoxin and positive results in six characters: lysine decarboxylase and Voges-Proskauer reactions, production of gas from glucose, gluconate oxidation, xanthine hydrolysis, and hemolysis of human erythrocytes. In the majority of cases (35 of 39 strains), enterotoxigenicity was detected using cell-free filtrates of brain heart infusion broth cultures grown at 36 degrees C for 15; however, the other four positive isolates were detected after growth in the same broth at 30 degrees C or in Casamino Acids-yeast extract broth at 30 or 37 degrees C. It is recommended that for enterotoxin tests, strains should be grown in both media at both temperatures. The infant mouse test was found to be a simple and reliable method for detection of the enterotoxin. The toxin proved to be heat labile and not neutralized by cholera antitoxin. PMID:6699147

  18. Distribution of Aeromonas phenospecies and genospecies among strains isolated from water, foods or from human clinical samples.

    PubMed Central

    Hänninen, M. L.; Siitonen, A.

    1995-01-01

    A total of 332 Aeromonas spp. originating from drinking water (n = 75), fresh water (n = 57), chicken and ground beef (107), human faecal samples in association with travelling (n = 49), human faecal samples not associated with travelling (n = 38), and six strains from human blood cultures were studied by phenotypic methods and by using analysis of ribopatterns as a molecular method for the identification of the 13 known hybridization groups (HGs). Also included were the reference strains of each HG. A. hydrophila HG 1, A. caviae HG 4 and A. veronii biotype sobria HG 8/10 were the most important genospecies identified in human faecal samples. A. hydrophila HG 2 and A. media HG 5B predominated in drinking water and A. hydrophila HG 2 and HG 3, A. media HG 5A and HG 5B predominated in fresh water. In drinking water only one isolate was A. hydrophila HG 1 and two isolates were A. caviae HG 4. Clinically important Aeromonas spp. HG 1 (A. hydrophila), HG 4 (A. caviae) and HG 8/10 (A. veronii biotype sobria) were common in chicken and ground beef. In contrast to the drinking water samples, HG 5A was common in chicken and ground beef samples. Atypical, unidentified isolates were most often found in fresh water samples (12/57 strains). Although water has been suspected of being an important source of human aeromonas infections, clinically important HGs were found to be in the minority among Aeromonas spp. identified in drinking water or fresh water. The distribution of Aeromonas spp. HGs among drinking water, chicken and ground beef samples was also different, suggesting that contamination of meat or chicken may not originate from water. Images Fig. 1 Fig. 2 PMID:7641837

  19. Recurrent Aeromonas Bacteremia Due to Contaminated Well Water

    PubMed Central

    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

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

    PubMed

    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

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

    USGS Publications Warehouse

    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.

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

    PubMed

    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

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

    PubMed Central

    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

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

    PubMed

    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

  5. Mixture of Sodium Hypochlorite and Hydrogen Peroxide on Adhered Aeromonas hydrophila to Solid Substrate in Water: Impact of Concentration and Assessment of the Synergistic Effect

    PubMed Central

    Lontsi Djimeli, Chrétien; Tamsa Arfao, Antoine; Noah Ewoti, Olive V.; Nougang, Mireille Ebiane; Moungang, Marlyse L.; Nola, Moïse; Sime-Ngando, Télesphore

    2014-01-01

    The synergistic effects of the combined treatments of NaOCl and H2O2 on the elimination of A. hydrophila adhered to polythene under static and dynamic conditions were evaluated. The concentrations 0.1, 0.2, and 0.3‰ NaOCl and 0.5, 1, and 1.5‰ H2O2 were used. The contact periods were 180, 360, 540, and 720 minutes. The abundance of cells adhered reached 2.47 and 2.27 units (log (CFU/cm²)), respectively, under static and dynamic conditions after action of the mixture of disinfectants, whereas it reached 2.41 and 3.39 units (log (CFU/cm²)) after action of NaOCl and H2O2 alone, respectively. Increase in the incubation period resulted in a significant decrease in the abundance of cells adhered when the mixture of 0.3‰ NaOCl and 1.5‰ H2O2 was used (P < 0.01). For each cell growth phase, there was a significant difference amongst the mean densities of cells adhered after action of the mixture of disinfectants (P < 0.05). Although the Freundlich isotherm parameters relatively varied from one experimental condition to another, the Kf value registered in the exponential growth phase was relatively higher in static state than in dynamic regime; cells adhered under dynamic condition seem more sensitive to the synergistic action than those adhered under static condition. PMID:26904729

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

    PubMed

    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

  7. Virulence Diversity among Bacteremic Aeromonas Isolates: Ex Vivo, Animal, and Clinical Evidences

    PubMed Central

    Chen, Po-Lin; Wu, Chi-Jung; Tsai, Pei-Jane; Tang, Hung-Jen; Chuang, Yin-Ching; Lee, Nan-Yao; Lee, Ching-Chi; Li, Chia-Wen; Li, Ming-Chi; Chen, Chi-Chung; Tsai, Hung-Wen; Ou, Chun-Chun; Chen, Chang-Shi; Ko, Wen-Chien

    2014-01-01

    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. PMID:25375798

  8. Insight into the mobilome of Aeromonas strains

    PubMed Central

    Piotrowska, Marta; Popowska, Magdalena

    2015-01-01

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

  9. Cloning, Sequencing, and Role in Virulence of Two Phospholipases (A1 and C) from Mesophilic Aeromonas sp. Serogroup O:34

    PubMed Central

    Merino, Susana; Aguilar, Alicia; Nogueras, Maria Mercedes; Regue, Miguel; Swift, Simon; Tomás, Juan M.

    1999-01-01

    Two different representative recombinant clones encoding Aeromonas hydrophila lipases were found upon screening on tributyrin (phospholipase A1) and egg yolk agar (lecithinase-phospholipase C) plates of a cosmid-based genomic library of Aeromonas hydrophila AH-3 (serogroup O34) introduced into Escherichia coli DH5α. Subcloning, nucleotide sequencing, and in vitro-coupled transcription-translation experiments showed that the phospholipase A1 (pla) and C (plc) genes code for an 83-kDa putative lipoprotein and a 65-kDa protein, respectively. Defined insertion mutants of A. hydrophila AH-3 defective in either pla or plc genes were defective in phospholipase A1 and C activities, respectively. Lecithinase (phospholipase C) was shown to be cytotoxic but nonhemolytic or poorly hemolytic. A. hydrophila AH-3 plc mutants showed a more than 10-fold increase in their 50% lethal dose on fish and mice, and complementation of the plc single gene on these mutants abolished this effect, suggesting that Plc protein is a virulence factor in the mesophilic Aeromonas sp. serogroup O:34 infection process. PMID:10417167

  10. Dietary low or excess levels of lipids reduced growth performance, and impaired immune function and structure of head kidney, spleen and skin in young grass carp (Ctenopharyngodon idella) under the infection of Aeromonas hydrophila.

    PubMed

    Ni, Pei-Jun; Jiang, Wei-Dan; Wu, Pei; Liu, Yang; Kuang, Sheng-Yao; Tang, Ling; Tang, Wu-Neng; Zhang, Yong-An; Zhou, Xiao-Qiu; Feng, Lin

    2016-08-01

    Our study explored the effect of dietary lipids on growth and immunity and structure (head kidney, spleen and skin) of young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp with an average initial weight of 261.41 ± 0.53 g were fed diets containing six graded levels of lipids at 5.9-80.1 g/kg diet for 8 weeks. After that, a challenge trial was conducted by injection of Aeromonas hydrophila over 2 weeks. The results indicated that compared with optimal lipids supplementation, low and excess levels of lipids down-regulated the mRNA levels of antimicrobial peptides, anti-inflammatory cytokines, inhibitor of κBα (IκBα) and ribosomal p70S6 kinase (S6K1), and up-regulated pro-inflammatory cytokines, nuclear factor κB p65 (NF-κB p65), NF-κB c-Rel (not p52), IκB kinase α (IKKα), IKKβ, IKKγ, and eIF4E-binding protein (4EBP) mRNA levels in the head kidney and spleen of young grass carp (P < 0.05). Low or excess levels of lipids also increased reactive oxygen species (ROS) production and malondialdehyde (MDA) and protein carbonyl (PC) contents, reduced the activities of antioxidant enzymes (P < 0.05), down-regulate the relative mRNA levels of antioxidant enzymes and NF-E2-related factor 2 (Nrf2), and up-regulated the expression levels of Kelch-like ECH-associating protein 1a (Keap1a) and Keap1b in the head kidney and spleen. In addition, low or excess levels of lipids down-regulated the mRNA levels of B-cell lymphoma-2 (Bcl-2) and inhibitor of apoptosis protein (IAP) in the head kidney and spleen, whereas up-regulated the mRNA levels of apoptotic protease activating factor-1 (Apaf-1), caspase 3, 7, 8 and 9 mRNA levels in the head kidney and spleen and Fas ligand (FasL) mRNA levels in the spleen of young grass carp, suggesting that low or excess levels of lipids could decrease the head kidney and spleen immune function, induce oxidative damage and apoptosis and impair antioxidant system of young grass carp. At last, low or excess

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

    PubMed

    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

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

    PubMed Central

    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-blaOXA-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-blaOXA-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 blaCTX-M-3, blaTEM-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

  13. Vibrio cholerae and Aeromonas: do they share a mutual host?

    PubMed

    Senderovich, Yigal; Gershtein, Yana; Halewa, Etti; Halpern, Malka

    2008-03-01

    Species of the genus Aeromonas are native inhabitants of aquatic environments and have recently been considered as an emergent human pathogen. It is estimated that aeromonads cause up to 13% of reported gastroenteritis cases in the United States. Although the autochthonous existence of Aeromonas in the aquatic environment has been established, its natural reservoir is as yet unknown. Chironomids are closely related to mosquitoes except they do not bite and they are the most widely distributed insects in freshwater. They infest drinking water systems in Israel and all over the world. Vibrio cholerae inhabit chironomids and are able to degrade their egg masses. The degradation of the egg masses is followed by failure of the eggs to hatch. In the current study, egg masses from a waste stabilization pond and a river in northern Israel were collected and cultured during a five-month period. Bacterial colonies were randomly chosen and checked for their egg mass degradation abilities. In addition to V. cholerae, most of the other isolates that had the ability to degrade the egg masses were identified as Aeromonas species, thus, demonstrating that Aeromonas species are natural inhabitants of chironomid egg masses. The following virulence-associated genes were detected in Aeromonas species that were isolated from chironomid egg masses: alt (78%); ahpB (76%); act/aerA/hlyA (65%); fla (59%); pla/lipH3/apl-1/lip (43%); and ast (2%). These findings indicate that the Aeromonas species inhabiting chironomid egg masses pose a potential health risk. Understanding the natural reservoir of Aeromonas will help to develop methods to monitor and control the bacteria in fresh and drinking water reservoirs and to better understand the relationships between chironomids, V. cholerae and Aeromonas populations. PMID:18317460

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

    PubMed

    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

  15. Multidrug-resistant (MDR) Aeromonas recovered from the metropolitan area of Valencia (Spain): diseases spectrum and prevalence in the environment.

    PubMed

    Esteve, C; Alcaide, E; Giménez, M J

    2015-01-01

    Aeromonas infections are rare in Europe and often related to traveller's diarrhoea. A total of 185 Aeromonas isolates from river water, fish and clinical sources, recovered during a 1-year period, were used to investigate the disease spectrum and impact of multidrug-resistant (MDR) strains. They were all identified by biochemical tests and 25% of them were also identified by sequencing of the 16S rRNA gene. The minimum inhibitory concentrations (MICs) of 21 antimicrobials were determined for all isolates by broth microdilution/E-strips methods, and susceptibility was assessed according to the Clinical and Laboratory Standards Institute (CLSI). Strains pathogenicity was determined by using Swiss Webster mice as the animal model. Aeromonas diseases had an incidence of around 20 cases/million inhabitants in the metropolitan area of Valencia (Spain). Acute gastroenteritis in children with no history of travel abroad was the main pathology. These cases were related to A. caviae, A. veronii biovar sobria, A. hydrophila and A. dhakensis. A significant incidence of A. caviae in humans was found, while the other species were equally present in clinical and environmental origins. A. jandaei, A. bestiarum and A. media had mainly an environmental distribution. The prevalence of MDR Aeromonas was maximal in clinical samples, and resistance phenotypes were significantly related to this source. 7.2% of environmental Aeromonas was resistant to at least five drugs; most of them were moderately virulent for mice and, in addition, belonged to clinically significant species. The present study demonstrates a diseases spectrum similar to that reported in tropical countries, and also that pathogenic and heavily MDR Aeromonas are present in environmental reservoirs. MDR Aeromonas from any source analysed were susceptible to aztreonam, netilmicin, cefotaxime, ceftazidime, cefepime and fluoroquinolones. PMID:25082185

  16. Aeromonas Surface Glucan Attached through the O-Antigen Ligase Represents a New Way to Obtain UDP-Glucose

    PubMed Central

    Merino, Susana; Bouamama, Lamiaa; Knirel, Yuriy A.; Senchenkova, Sofya N.; Regué, Miguel; Tomás, Juan M.

    2012-01-01

    We previously reported that A. hydrophila GalU mutants were still able to produce UDP-glucose introduced as a glucose residue in their lipopolysaccharide core. In this study, we found the unique origin of this UDP-glucose from a branched α-glucan surface polysaccharide. This glucan, surface attached through the O-antigen ligase (WaaL), is common to the mesophilic Aeromonas strains tested. The Aeromonas glucan is produced by the action of the glycogen synthase (GlgA) and the UDP-Glc pyrophosphorylase (GlgC), the latter wrongly indicated as an ADP-Glc pyrophosphorylase in the Aeromonas genomes available. The Aeromonas glycogen synthase is able to react with UDP or ADP-glucose, which is not the case of E. coli glycogen synthase only reacting with ADP-glucose. The Aeromonas surface glucan has a role enhancing biofilm formation. Finally, for the first time to our knowledge, a clear preference on behalf of bacterial survival and pathogenesis is observed when choosing to produce one or other surface saccharide molecules to produce (lipopolysaccharide core or glucan). PMID:22563467

  17. Aeromonas hydrophila in a burn patient.

    PubMed

    Yasti, Ahmet Cinar; Otan, Emrah; Doganay, Mutlu; Kama, Nuri A

    2009-01-01

    Infectious consequences are still a major problem and leading cause of mortality in burn patients. Among others, aeromonads need special concern because they mimic pseudomonal infections; however, they have a more rapid progression with considerable mortality if undiagnosed promptly. Here, we present a major burn case extinguished with tap water pooled in a tank. With the possibility of aeromonal infection in mind, the patient underwent aggressive debridement with proper antibiotic medication, which resulted in a successful patient management. Aeromonads should always be kept in mind in burn cases that contacted with tanked water or soil after the burn. PMID:19692919

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

    PubMed Central

    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

  19. Aeromonas Caviae Strain Induces Th1 Cytokine Response in Mouse Intestinal Tract

    EPA Science Inventory

    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 i...

  20. Distribution and phenotypic and genotypic detection of a metallo-β-lactamase, CphA, among bacteraemic Aeromonas isolates.

    PubMed

    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

  1. Clustering subspecies of Aeromonas salmonicida using IS630 typing

    PubMed Central

    2013-01-01

    Background The insertion element IS630 found in Aeromonas salmonicida belongs to the IS630-Tc1-mariner superfamily of transposons. It is present in multiple copies and represents approximately half of the IS present in the genome of A. salmonicida subsp. salmonicida A449. Results By using High Copy Number IS630 Restriction Fragment Length Polymorphism (HCN-IS630-RFLP), strains of various subspecies of Aeromonas salmonicida showed conserved or clustering patterns, thus allowing their differentiation from each other. Fingerprints of A. salmonicida subsp. salmonicida showed the highest homogeneity while ‘atypical’ A. salmonicida strains were more heterogeneous. IS630 typing also differentiated A. salmonicida from other Aeromonas species. The copy number of IS630 in Aeromonas salmonicida ranges from 8 to 35 and is much lower in other Aeromonas species. Conclusions HCN-IS630-RFLP is a powerful tool for subtyping of A. salmonicida. The high stability of IS630 insertions in A. salmonicida subsp. salmonicida indicates that it might have played a role in pathoadaptation of A. salmonicida which has reached an optimal configuration in the highly virulent and specific fish pathogen A. salmonicida subsp. salmonicida. PMID:23406017

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

    PubMed

    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

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

    PubMed

    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

  4. Aeromonas salmonicida: updates on an old acquaintance.

    PubMed

    Menanteau-Ledouble, Simon; Kumar, Gokhlesh; Saleh, Mona; El-Matbouli, Mansour

    2016-06-15

    Aeromonas salmonicida is the oldest known infectious agent to be linked to fish disease and constitutes a major bacterial pathogen of fish, in particular of salmonids. This bacterium can be found almost worldwide in both marine and freshwater environments and has been divided into several sub-species. In this review, we present the most recent developments concerning our understanding of this pathogen, including how the characterization of new isolates from non-salmonid hosts suggests a more nuanced picture of the importance of the so‑called 'atypical isolates'. We also describe the clinical presentation regarding the infection across several fish species and discuss what is known about the virulence of A. salmonicida and, in particular, the role that the type 3 secretion system might play in suppressing the immune response of its hosts. Finally, isolates have displayed varied levels of antibiotic resistance. Hence, we review a number of solutions that have been developed both to prevent outbreaks and to treat them once they occur, including the application of pre- and probiotic supplements. PMID:27304870

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

    PubMed

    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

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

    PubMed

    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

  7. Reduction of Aeromonas hidrophyla biofilm on stainless stell surface by essential oils

    PubMed Central

    Millezi, Alessandra Farias; Cardoso, Maria das Graças; Alves, Eduardo; Piccoli, Roberta Hilsdorf

    2013-01-01

    This study demonstrates the possibility of using sanitizing detergents based on natural products for the elimination and/or reduction of Aeromonas hydrophila biofilm formed on stainless steel surfaces. The goal of this work was to determine the reduction effect of sanitizing detergents containing essential oils of Thymus vulgaris (thyme) and Cymbopogon citratus (lemongrass) on biofilm formed by A. hydrophila on AISI 304 stainless steel coupons, using UHT skimmed milk as substratum. There was adhesion and biofilm formation by A. hydrophila at 28 °C, presenting 7.60 log cfu.cm−2 after the fourth day of cultivation. There was no significant difference between the lemongrass treatment and that of the thyme oil (p < 0.05). However, both treatments significantly reduced the biofilm, differing significantly from the NaOH control (p > 0.05). The treatment with lemongrass solution reduced the biofilm by 4.51 log cfu cm−2 at 25 °C. The thyme detergent also reduced the number of cfu cm−2 by 3.84 log cycles at 25 °C. The use of the lemongrass and thyme solutions efficiently reduced the A. hydrophila biofilm. PMID:24159286

  8. Reduction of Aeromonas hidrophyla biofilm on stainless stell surface by essential oils.

    PubMed

    Millezi, Alessandra Farias; Cardoso, Maria das Graças; Alves, Eduardo; Piccoli, Roberta Hilsdorf

    2013-01-01

    This study demonstrates the possibility of using sanitizing detergents based on natural products for the elimination and/or reduction of Aeromonas hydrophila biofilm formed on stainless steel surfaces. The goal of this work was to determine the reduction effect of sanitizing detergents containing essential oils of Thymus vulgaris (thyme) and Cymbopogon citratus (lemongrass) on biofilm formed by A. hydrophila on AISI 304 stainless steel coupons, using UHT skimmed milk as substratum. There was adhesion and biofilm formation by A. hydrophila at 28 °C, presenting 7.60 log cfu.cm(-2) after the fourth day of cultivation. There was no significant difference between the lemongrass treatment and that of the thyme oil (p < 0.05). However, both treatments significantly reduced the biofilm, differing significantly from the NaOH control (p > 0.05). The treatment with lemongrass solution reduced the biofilm by 4.51 log cfu cm(-2) at 25 °C. The thyme detergent also reduced the number of cfu cm(-2) by 3.84 log cycles at 25 °C. The use of the lemongrass and thyme solutions efficiently reduced the A. hydrophila biofilm. PMID:24159286

  9. Prospective Nationwide Study of Aeromonas Infections in France▿

    PubMed Central

    Lamy, Brigitte; Kodjo, Angeli; Laurent, Frédéric

    2009-01-01

    We report a systematic prospective multicenter nationwide study of clinical Aeromonas infections in France. During 6 months (May to October 2006), 78 cases of aeromonosis were reviewed for risk factors and clinical, microbiological, and antimicrobial susceptibility data. They included wound infections (44%), bacteremia (26%), enteritis (19%), respiratory tract infections (6%), and miscellaneous (5%) infections. PMID:19244464

  10. SENSITIVITY OF DIFFERENT AEROMONAS SPECIES TO COPPER AND SILVER

    EPA Science Inventory

    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 ...

  11. PCR detection, characterization, and distribution of virulence genes in Aeromonas spp.

    PubMed

    Kingombe, C I; Huys, G; Tonolla, M; Albert, M J; Swings, J; Peduzzi, R; Jemmi, T

    1999-12-01

    We found 73.1 to 96.9% similarity by aligning the cytolytic enterotoxin gene of Aeromonas hydrophila SSU (AHCYTOEN; GenBank accession no. M84709) against aerolysin genes of Aeromonas spp., suggesting the possibility of selecting common primers. Identities of 90 to 100% were found among the eight selected primers from those genes. Amplicons obtained from Aeromonas sp. reference strains by using specific primers for each gene or a cocktail of primers were 232 bp long. Of hybridization group 4/5A/5B (HG4/5A/5B), HG9, and HG12 or non-Aeromonas reference strains, none were positive. PCR-restriction fragment length polymorphism (PCR-RFLP) with HpaII yielded three types of patterns. PCR-RFLP 1 contained two fragments (66 and 166 bp) found in HG6, HG7, HG8, HG10, and HG11. PCR-RFLP 2 contained three fragments (18, 66, and 148 bp) found in HG1, HG2, HG3, and HG11. PCR-RFLP 3, with four fragments (7, 20, 66, and 139 bp), was observed only in HG13. PCR-amplicon sequence analysis (PCR-ASA) revealed three main types. PCR-ASA 1 had 76 to 78% homology with AHCYTOEN and included strains in HG6, HG7, HG8, HG10, and HG11. PCR-ASA 2, with 82% homology, was found only in HG13. PCR-ASA 3, with 91 to 99% homology, contained the strains in HG1, HG2, HG3, and HG11. This method indicated that 37 (61%) of the 61 reference strains were positive with the primer cocktail master mixture, and 34 (58%) of 59 environmental isolates, 93 (66%) of 141 food isolates, and 100 (67%) of 150 clinical isolates from around the world carried a virulence factor when primers AHCF1 and AHCR1 were used. In conclusion, this PCR-based method is rapid, sensitive, and specific for the detection of virulence factors of Aeromonas spp. It overcomes the handicap of time-consuming biochemical and other DNA-based methods. PMID:10583979

  12. Prevalence, virulence and antimicrobial resistance patterns of Aeromonas spp. isolated from children with diarrhea

    PubMed Central

    Soltan Dallal, Mohammad Mehdi; Mazaheri Nezhad Fard, Ramin; Kavan Talkhabi, Morteza; Aghaiyan, Leyla; Salehipour, Zohre

    2016-01-01

    Background Aeromonas spp. cause various intestinal and extraintestinal diseases. These bacteria are usually isolated from fecal samples, especially in children under five years old. The aim of this study was to assess the prevalence of Aeromonas spp. and their antimicrobial resistance profile in children with diarrhea referred to the Children Medical Center in Tehran, between 2013 and 2014. Methods A total number of 391 stool samples were collected from children with ages between 1 day and 14 years old, with diarrhea (acute or chronic), referred to the Children Hospital, Tehran, Iran, between 2013 and 2014. Samples were enriched in alkaline peptone water broth for 24 hours at 37 °C and then cultured. Suspicious colonies were analyzed through biochemical tests. Furthermore, antimicrobial susceptibility tests were carried out for the isolates. Isolates were further studied for act, ast, alt, aerA and hlyA virulence genes using polymerase chain reaction. Results In total, 12 isolates (3.1%) were identified as Aeromonas spp.; all were confirmed using the API-20E test. Of these isolates, five A. caviae (42%), four A. veronii (33%) and three A. hydrophila (25%) were identified in cases with gastroenteritis. Second to ampicillin (which was included in the growth medium used), the highest rate of antimicrobial resistance was seen against nalidixic acid and trimethoprim-sulfamethoxazole (5 isolates each, 41.6%) and the lowest rate of antimicrobial resistance was seen against gentamicin, amikacin and cefepime (none of the isolates). Results included 76.4% act, 64.7% ast, 71.5% alt, 83.3% aerA and 11.7% hlyA genes. Conclusion Aeromonas spp. are important due to their role in diarrhea in children; therefore, isolation and identification of these fecal pathogens should seriously be considered in medical laboratories. Since virulence genes play a significant role in gastroenteritis symptoms caused by these bacteria, Aeromonas species that include virulence genes are potentially

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

    PubMed

    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

  14. Genetic and biochemical characterization of TRU-1, the endogenous class C beta-lactamase from Aeromonas enteropelogenes.

    PubMed

    De Luca, Filomena; Giraud-Morin, Chantal; Rossolini, Gian Maria; Docquier, Jean-Denis; Fosse, Thierry

    2010-04-01

    Aeromonas enteropelogenes (formerly A. tructi) was described to be an ampicillin-susceptible and cephalothin-resistant Aeromonas species, which suggests the production of a cephalosporinase. Strain ATCC 49803 was susceptible to amoxicillin, cefotaxime, and imipenem but resistant to cefazolin (MICs of 2, 0.032, 0.125, and >256 microg/ml, respectively) and produced an inducible beta-lactamase. Cefotaxime-resistant mutants (MIC, 32 microg/ml) that showed constitutive beta-lactamase production could be selected in vitro. The gene coding for the cephalosporinase of A. enteropelogenes ATCC 49803 was cloned, and its biochemical properties were investigated. Escherichia coli transformants showing resistance to various beta-lactams carried a 3.5-kb plasmid insert whose sequence revealed a 1,146-bp open reading frame (ORF) encoding a class C beta-lactamase, named TRU-1, showing the highest identity scores with A. punctata CAV-1 (75%), A. salmonicida AmpC (75%), and A. hydrophila CepH (71%). The bla(TRU-1) locus includes open reading frames (ORFs) showing significant homology with genes found in the genomes of other Aeromonas species, although it exhibits a different organization, as reflected by the presence of additional ORFs located downstream of the beta-lactamase gene in the A. hydrophila and A. salmonicida genomes. Specific PCR assays were negative for cphA-like and bla(OXA-12)-like genes in three A. enteropelogenes ATCC strains. Purified TRU-1 showed a broad substrate profile, efficiently hydrolyzing benzylpenicillin, cephalothin, cefoxitin, and, although with significantly lower turnover rates, oxyiminocephalosporins. Cephaloridine and cefepime were poorly recognized by the enzyme, as reflected by the high K(m) values observed with these substrates. Thus far, A. enteropelogenes represents the only known example of an Aeromonas species that produces only one beta-lactamase belonging to molecular class C. PMID:20124004

  15. Faecal contamination indicators, Salmonella, Vibrio and Aeromonas in water used for the irrigation of agricultural products.

    PubMed Central

    Pianietti, A.; Sabatini, L.; Bruscolini, F.; Chiaverini, F.; Cecchetti, G.

    2004-01-01

    The faecal contamination indicators (total coliforms, faecal coliforms, Escherichia coli, enterococci) and the genera Salmonella, Vibrio, Aeromonas were investigated in water samples used for irrigation. During 4 months, 52 samples were taken. The methods used were: multiple tube fermentation method for faecal contamination indicators and membrane filtration techniques for salmonella, aeromonas and vibrio. Two samples were positive for Salmonella spp., fourteen for Aeromonas spp. and no samples for Vibrio spp. No correlation was found between aeromonas and the indicators of faecal contamination. Regarding Aeromonas spp., 21.6% of the strains were adhesive and 12.6% cytotoxic: this confirms the possible role of aeromonas in human pathologies. These results are important to determine the quality of irrigation water in relation to human health. In fact, the spray or sprinkler irrigation produces bioaerosol, which can contaminate the crops that are likely to be eaten uncooked. In addition, the flood or furrow irrigation represents a risk to field workers. PMID:15061497

  16. Denaturing gradient gel electrophoresis for nonlethal detection of Aeromonas salmonicida in salmonid mucus and its potential for other bacterial fish pathogens.

    PubMed

    Quinn, Robert A; Stevenson, Roselynn M W

    2012-05-01

    Denaturing gradient gel electrophoresis (DGGE) of 16S rDNA was used to nonlethally detect Aeromonas salmonicida and other bacteria in salmonid skin mucus. Mucus samples from wild spawning coho salmon (Oncorhynchus kisutch) with endemic A. salmonicida and from cultured lake trout (Salvelinus namaycush) were tested by PCR-DGGE and were compared with mucus culture on Coomassie brilliant blue agar and internal organ culture. PCR-DGGE gave a highly reproducible 4-band pattern for 9 strains of typical A. salmonicida, which was different from other Aeromonas spp. Aeromonas salmonicida presence in mucus was evident as a band that comigrated with the bottom band of the A. salmonicida 4-band pattern and was verified by sequencing. PCR-DGGE found 36 of 52 coho salmon positive for A. salmonicida, compared with 31 positive by mucus culture and 16 by organ culture. Numerous other bacteria were detected in salmonid mucus, including Pseudomonas spp., Shewanella putrefaciens, Aeromonas hydrophila and other aeromonads. However, Yersinia ruckeri was not detected in mucus from 27 lake trout, but 1 fish had a sorbitol-positive Y. ruckeri isolated from organ culture. Yersinia ruckeri seeded into a mucus sample suggested that PCR-DGGE detection of this bacterium from mucus was possible. PCR-DGGE allows nonlethal detection of A. salmonicida in mucus and differentiation of some Aeromonas spp. and has the potential to allow simultaneous detection of other pathogens present in fish mucus. PMID:22506865

  17. Virulence characteristics of Aeromonas spp. in relation to source and biotype.

    PubMed Central

    Kirov, S M; Rees, B; Wellock, R C; Goldsmid, J M; Van Galen, A D

    1986-01-01

    The significance of Aeromonas spp. as potential water-borne enteric pathogens in Tasmania, Australia, an area with a mild climate and comparatively low year-round water temperatures, was investigated in view of the reported marked peak of Aeromonas-associated gastroenteritis in the summer and the apparent influence of temperature on levels of potentially pathogenic species in water supplies. Biochemical characteristics and virulence-associated properties--exotoxin production (hemolysin, enterotoxin), ability to grow at 43 degrees C, and possession of pili--were determined for 105 Tasmanian isolates of Aeromonas spp.; 43 isolates were from clinical specimens (greater than 75% diarrhea associated) and 62 were from water. Current classification schemes were evaluated for these isolates. A. sobria comprised 35% of the clinical isolates and 16% of the water isolates, A. hydrophila comprised 56 and 79%, and A. caviae comprised 9 and 5%. A total of 42% of the clinical isolates and 15% of the environmental isolates were enterotoxigenic (by the suckling mouse assay); these levels were significantly lower than those found in warmer environments. The majority (74%) of enterotoxigenic isolates were A. sobria. Enterotoxin-producing isolates possessed three or more of the following properties. They were Voges-Proskauer positive, did not hydrolyze arabinose, were positive for lysine decarboxylase, were able to grow at 43 degrees C, and produced large amounts of hemolysin (titer, greater than 128). Thus, the biochemical scheme proposed by Burke et al. (V. Burke, J. Robinson, H.M. Atkinson, and M. Gracey, J. Clin. Microbiol. 15:48-52, 1982) for identifying enterotoxigenic isolates appears to have widespread applicability. Environmental enterotoxigenic isolates possessed numerous pili, but these appeared to be lost once infection was established, as a similar isolates from patients with diarrhea were poorly piliated. Images PMID:2877008

  18. Hemerythrin is required for Aeromonas hydraphlia to survive in the macrophages of Anguilla japonica.

    PubMed

    Zeng, W B; Chen, W B; Yan, Q P; Lin, G F; Qin, Y X

    2016-01-01

    Survival in host phagocytes is an effective strategy for pathogenic microbes to spread. To understand the mechanisms of Aeromonas hydrophila survival within host macrophages, a library of mini-Tn10 transposon insertion mutants was constructed. The M85 mutant, whose survival in host macrophages was only 23.1% of that of the wild-type (WT) strain, was utilized for further study. Molecular analysis showed that a 756-bp open reading frame (ORF) (GenBank accession No. CP007576) in the M85 mutant was interrupted by mini-Tn10. This ORF encodes for a 183-amino acid protein and displays the highest sequence identity (99%) with the hemerythrin (Hr) protein of A. hydrophila subspecies hydrophila ATCC 7966. The survival of the WT, M85 mutant, and complemented M85 (Hr) strains were compared in host macrophages in vitro, and the results showed that M85 exhibited defective survival, while that of M85 (Hr) was restored. To investigate the possible mechanisms of A. hydrophila survival in host macrophages, the expression of Hr under hyperoxic and hypoxic conditions was evaluated. The results revealed that the expression of this protein was higher under hyperoxic conditions than under hypoxic conditions, which indicates that Hr protein expression is sensitive to O2 concentration. Hydrogen peroxide sensitivity tests further suggested that the M85 mutant was more sensitive to oxidative stress than the WT and M85 (Hr) strains. Taken together, these results suggest that the Hr protein may act as an O2 sensor and as a detoxifier of reactive oxygen species, and is required for A. hydrophila survival within host macrophages. PMID:27173333

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

    PubMed

    Merino, Susana; Tomás, Juan M

    2016-01-01

    Initial hydridization tests using Aeromonas salmonicida typical and atypical strains showed the possibility of different lipopolysaccharide (LPS) outer cores among these strains. By chemical structural analysis, LPS-core SDS-PAGE gel migration, and functional and comparative genomics we demonstrated that typical A. salmonicida (subsp. salmonicida) strains and atypical subsp. masoucida and probably smithia strains showed the same LPS outer core. A. salmonicida subsp. achromogenes strains show a similar LPS outer core but lack one of the most external residues (a galactose linked α1-6 to heptose), not affecting the O-antigen LPS linkage. A. salmonicida subsp. pectinolytica strains show a rather changed LPS outer core, which is identical to the LPS outer core from the majority of the A. hydrophila strains studied by genomic analyses. The LPS inner core in all tested A. salmonicida strains, typical and atypical, is well-conserved. Furthermore, the LPS inner core seems to be conserved in all the Aeromonas (psychrophilic or mesophilic) strains studied by genomic analyses. PMID:26904002

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

    PubMed Central

    Merino, Susana; Tomás, Juan M.

    2016-01-01

    Initial hydridization tests using Aeromonas salmonicida typical and atypical strains showed the possibility of different lipopolysaccharide (LPS) outer cores among these strains. By chemical structural analysis, LPS-core SDS-PAGE gel migration, and functional and comparative genomics we demonstrated that typical A. salmonicida (subsp. salmonicida) strains and atypical subsp. masoucida and probably smithia strains showed the same LPS outer core. A. salmonicida subsp. achromogenes strains show a similar LPS outer core but lack one of the most external residues (a galactose linked α1-6 to heptose), not affecting the O-antigen LPS linkage. A. salmonicida subsp. pectinolytica strains show a rather changed LPS outer core, which is identical to the LPS outer core from the majority of the A. hydrophila strains studied by genomic analyses. The LPS inner core in all tested A. salmonicida strains, typical and atypical, is well-conserved. Furthermore, the LPS inner core seems to be conserved in all the Aeromonas (psychrophilic or mesophilic) strains studied by genomic analyses. PMID:26904002

  1. Aeromonas dhakensis pneumonia and sepsis in a neonate Risso's dolphin Grampus griseus from the Mediterranean Sea.

    PubMed

    Pérez, Lola; Abarca, M Lourdes; Latif-Eugenín, Fadua; Beaz-Hidalgo, Roxana; Figueras, M José; Domingo, Mariano

    2015-09-17

    A neonate Risso's dolphin Grampus griseus was found stranded alive on a beach in Catalonia, Spain. Rehabilitation attempts were unsuccessful and it died 2 d later, showing pneumonia and sepsis. A pure bacterial culture was obtained from all tissues and blood and identified as Aeromonas hydrophila using the API 20NE. However, sequencing the rpoD gene showed that the strain in fact belongs to A. dhakensis, making this the first report of fatal haemorrhagic-necrotizing pneumonia and sepsis due to this species in a marine mammal. The A. dhakensis strain GMV-704 produced β-haemolysis, possessed several virulence genes and showed sensitivity to several antimicrobials. This study provides a new potential host for A. dhakensis, and its potential virulence in dolphins and its presence in the marine environment may warrant considering this species a potential threat to marine mammals. PMID:26378409

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

    PubMed

    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

  3. Antimicrobial Susceptibilities of Aeromonas spp. Isolated from Environmental Sources▿

    PubMed Central

    Huddleston, Jennifer R.; Zak, John C.; Jeter, Randall M.

    2006-01-01

    Aeromonas spp. are ubiquitous aquatic bacteria that cause serious infections in both poikilothermic and endothermic animals, including humans. Clinical isolates have shown an increasing incidence of antibiotic and antimicrobial drug resistance since the widespread use of antibiotics began. A total of 282 Aeromonas pure cultures were isolated from both urban and rural playa lakes in the vicinity of Lubbock, Texas, and several rivers in West Texas and New Mexico. Of these, at least 104 were subsequently confirmed to be independent isolates. The 104 isolates were identified by Biolog and belonged to 11 different species. The MICs of six metals, one metalloid, five antibiotics, and two antimicrobial drugs were determined. All aeromonads were sensitive to chromate, cobalt, copper, nickel, zinc, cefuroxime, kanamycin, nalidixic acid, ofloxacin, tetracycline, and sulfamethoxazole. Low incidences of trimethoprim resistance, mercury resistance, and arsenite resistance were found. Dual resistances were found in 5 of the 104 Aeromonas isolates. Greater numbers of resistant isolates were obtained from samples taken in March versus July 2002 and from sediment versus water. Plasmids were isolated from selected strains of the arsenite- and mercury-resistant organisms and were transformed into Escherichia coli XL1-Blue MRF′. Acquisition of the resistance phenotypes by the new host showed that these resistance genes were carried on the plasmids. Mercury resistance was found to be encoded on a conjugative plasmid. Despite the low incidence of resistant isolates, the six playa lakes and three rivers that were sampled in this study can be considered a reservoir for antimicrobial resistance genes. PMID:16950901

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

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

    2015-02-01

    The potential control efficacy of Aeromonas phage PAS-1 was evaluated against Aeromonas salmonicida subsp. salmonicida infection in rainbow trout (Oncorhynchus mykiss) model in this study. The phage was co-cultured with the virulent A. salmonicida subsp. salmonicida strain AS05 that possesses the type III secretion system (TTSS) ascV gene, and efficient bacteriolytic activity was observed against the bacteria. The administration of PAS-1 in rainbow trout demonstrated that the phage was cleared from the fish within 200 h post-administration, and a temporal neutralizing activity against the phage was detected in the sera of phage-administrated fish. The administration of PAS-1 (multiplicity of infection: 10 000) in A. salmonicida subsp. salmonicida infected rainbow trout model showed notable protective effects, with increased survival rates and mean times to death. These results demonstrated that Aeromonas phage PAS-1 could be considered as an alternative biological control agent against A. salmonicida subsp. salmonicida infections in rainbow trout culture. PMID:23594036

  7. Novel role for Aeromonas jandaei as a digestive tract symbiont of the North American medicinal leech.

    PubMed

    Siddall, Mark E; Worthen, Paul L; Johnson, Matthew; Graf, Joerg

    2007-01-01

    The gut bacteria of the North American medicinal leech, Macrobdella decora, were characterized. Biochemical tests and DNA sequences indicated that Aeromonas jandaei is the dominant culturable symbiont in leeches from a broad geographic area. In this work we identified a new habitat for A. jandaei, and here we suggest that there is unexpected specificity between leeches and Aeromonas species. PMID:17114316

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

    EPA Science Inventory

    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...

  9. Distribution of Virulence Factors and Molecular Fingerprinting of Aeromonas Species Isolates from Water and Clinical Samples: Suggestive Evidence of Water-to-Human Transmission ▿ †

    PubMed Central

    Khajanchi, Bijay K.; Fadl, Amin A.; Borchardt, Mark A.; Berg, Richard L.; Horneman, Amy J.; Stemper, Mary E.; Joseph, Sam W.; Moyer, Nelson P.; Sha, Jian; Chopra, Ashok K.

    2010-01-01

    A total of 227 isolates of Aeromonas obtained from different geographical locations in the United States and different parts of the world, including 28 reference strains, were analyzed to determine the presence of various virulence factors. These isolates were also fingerprinted using biochemical identification and pulse-field gel electrophoresis (PFGE). Of these 227 isolates, 199 that were collected from water and clinical samples belonged to three major groups or complexes, namely, the A. hydrophila group, the A. caviae-A. media group, and the A. veronii-A. sobria group, based on biochemical profiles, and they had various pulsotypes. When virulence factor activities were examined, Aeromonas isolates obtained from clinical sources had higher cytotoxic activities than isolates obtained from water sources for all three Aeromonas species groups. Likewise, the production of quorum-sensing signaling molecules, such as N-acyl homoserine lactone, was greater in clinical isolates than in isolates from water for the A. caviae-A. media and A. hydrophila groups. Based on colony blot DNA hybridization, the heat-labile cytotonic enterotoxin gene and the DNA adenosine methyltransferase gene were more prevalent in clinical isolates than in water isolates for all three Aeromonas groups. Using colony blot DNA hybridization and PFGE, we obtained three sets of water and clinical isolates that had the same virulence signature and had indistinguishable PFGE patterns. In addition, all of these isolates belonged to the A. caviae-A. media group. The findings of the present study provide the first suggestive evidence of successful colonization and infection by particular strains of certain Aeromonas species after transmission from water to humans. PMID:20154106

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

    PubMed

    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

  11. [The suicide phenomenon and fermentative metabolic activity in strains of the Aeromonas group isolated from feces].

    PubMed

    Reina, J; Serra, A; Borrell, N; Gómez, J

    1992-11-01

    We study the "suicide" phenomena as well as metabolic pathways of mixed acids (methyl red test, MR) and butylene glycol (Voges-Proskauer, VP), in 107 strains belonging to mesophilic Aeromonas group, isolated from stools. The strains have been identified as A. hydrophila, 28 cases (26.1%), A. sobria 26 cases (24.3%) and A. caviae 53 cases (49.6%). All A. caviae strains behave homogeneously as F+, RM+ and VP-, independently of temperature (30 or 37 degrees C). A. hydrophila strains only showed their trend to "suicide" at 37 degrees C, being this behavior linked to RM test positivity. At 30 degrees C all strains were NS and RM-, keeping always positive the VP test (both temperatures). In A. sobria we have recorded changes in their behavior related to the temperature of incubation. At 37 degrees C, 57.7% were NS, whereas at 30 degrees C, 69.2% showed the same phenotype. The metabolic activity had remained stable, therefore F+ strains were VP and RM+, and NS strains were VP+ and RM-. It seems that FS is a phenotypic behavior of this bacterial group species and temperature-dependent, and also is related to a fermentative metabolic activity modulation of each of them. PMID:1489794

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

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed

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

    2015-11-01

    This study aimed to assess the antibiogram of Aeromonas strains recovered from cattle faeces and the potential pathogenic status of the isolates. The antibiogram of the Aeromonas isolates demonstrated total resistance to clindamycin oxacillin, trimethoprim, novobiocin and ticarcillin. However, Aeromonas strains were sensitive to cefotaxime, oxytetracycline and tobramycin. The Aeromonas strains from Lovedale and Fort Cox farms were found to possess some virulence genes. The percentage distribution was aer 71.4%, ast 35.7%, fla 60.7%, lip 35.7% and hlyA 25% for Lovedale farm and aer 63.1%, alt 10.5%, ast 55.2%, fla 78.9%, lip 21% and hlyA 35.9% for Fort Cox farm. Class 1 integron was present in 27% of Aeromonas isolates; the bla TEM gene was present in 34.8%, while the blaP1 class A β-lactamase gene was detected in 12.1% of the isolates. Approximately 86% of the isolates formed a biofilm on microtitre plates. The presence of multiple antibiotic resistance and virulence genes in Aeromonas isolates from cattle faeces reveals the pathogenic and infectious importance of these isolates and is of great significance to public health. The possession of a biofilm-forming capability by such isolates may lead to difficulty during the management of infection related to Aeromonas species. PMID:26143545

  14. A Variant Quorum Sensing System in Aeromonas veronii MTCC 3249

    PubMed Central

    Jangid, Kamlesh; Parameswaran, Perunninakulath S.; Shouche, Yogesh S.

    2012-01-01

    We have investigated the quorum sensing control in Aeromonas veronii MTCC 3249, originally isolated as A. culicicola from the midgut of Culex quinquefasciatus. Based on biosensor assays, the bacterium showed constant production of multiple acyl-homoserine lactones (AHLs) with increasing cell-density. The luxRI gene homologs, acuR (A. culicicola transcriptional Regulator) and acuI (A. culicicola autoInducer) were successfully amplified by inverse-PCR. Sequence analysis indicated acuRI were divergent from all known quorum sensing gene homologs in Aeromonas. Two localized regions in the C-terminal autoinducer binding domain of acuR showed indels suggesting variations in autoinducer specificity. Further, only a single copy of the quorum sensing genes was detected, suggesting a tight regulation of mechanisms under its control. Chromatography and further chemical analysis identified two AHLs in the culture supernatant: 6-carboxy-HHL (homoadipyl homoserine lactone), a novel AHL, and N-tetradecanoylhomoserine lactone. The existence of a potentially variant quorum sensing system might therefore, reflect in some way the ecological strategies adopted by this bacterium in the mosquito midgut. PMID:22666003

  15. Accuracy of 6 commercial systems for identifying clinical Aeromonas isolates.

    PubMed

    Lamy, Brigitte; Laurent, Frédéric; Verdier, Isabelle; Decousser, Jean-Winoc; Lecaillon, Evelyne; Marchandin, Hélène; Roger, Frédéric; Tigaud, Sylvestre; de Montclos, Henri; Kodjo, Angeli

    2010-05-01

    We compared the accuracy of 6 commercial systems for Aeromonas identification by testing 87 clinical isolates in routine conditions, using partial rpoB gene sequencing as the reference standard. The systems were API-20E, API-32GN, the ID-GN card with the Vitek2 system (bioMérieux, Marcy l'Etoile, France), the identification portion of the NFC47 panel (MicroScan Walk/Away system; Siemens Healthcare, Sacramento, CA), ID69 (Phoenix system; BD Diagnostic Systems, Sparks, MD), and GN2 microplates (Omnilog system; Biolog, Hayward, CA), for which 67 (77.1%), 80 (91.9%), 72 (82.7%), 70 (80.5%), 64 (73.5%), and 59 (67.8%) isolates, respectively, were correctly identified at the genus and species level. Confusion with Vibrio affected 6.9% and 16.1% of results obtained with NFC47 and API-20E, respectively. Overall, the accuracy of identification for aeromonads was hampered by outdated databases and taxonomy, weak algorithms, and impractical additional tests. Commercial identification systems should be redesigned to make Aeromonas identification algorithms more robust and to cover infrequent clinical species of this genus. PMID:20167449

  16. Detection of the frequency, antimicrobial susceptibility, and genotypic discrimination of Aeromonas strains isolated from municipally treated tap water samples by cultivation and AP-PCR.

    PubMed

    Emekdas, Gurol; Aslan, Gonul; Tezcan, Seda; Serin, Mehmet Sami; Yildiz, Cilem; Ozturhan, Hakan; Durmaz, Riza

    2006-04-01

    The frequency, antibiotic susceptibility, and genotypic discrimination of Aeromonas strains isolated from municipally treated drinking tap water distribution systems were investigated in this study. We have analyzed 148 tap water samples collected from 8 different locations by bacterial cultivation and arbitrarily primed polymerase chain reaction (AP-PCR). Gram negative, hemolytic, oxidase (+) and catalase (+) bacterial colonies were applied to the study. Identification of bacterial colonies was done by conventional biochemical method and API ID 20E panel (BioMerieux-France). Molecular epidemiological discrimination of the isolates was done by AP-PCR. Aeromonas spp. was detected in 6 of 148 (4%) tap water samples from 8 different locations. Five isolates were identified as Aeromonas hydrophila and one isolate was identified as Vibrio fluvialis by conventional biochemical method. These data were also confirmed by API 20E panel. One of 6 isolates was resistant to gentamicin, 2 of 6 isolates were resistant to trimethoprim/sulfamethoxazole, 4 of 6 isolates were resistant to ampicillin and ampicillin-sulbactam and all of 6 isolates were resistant to cephalothin. All isolates were found to be susceptible to amikacin, aztreonam, ceftazidime, ceftriaxone, ciprofloxacin. All 6 strains of Aeromonas were discriminated by AP-PCR and were determined that all isolates were from different genotypic sources. Although the frequency of the isolates was under the standard limits, the results indicate that hemolytic A. hydrophila are present in municipally treated tap water samples in Mersin City. While all strains were genotypically distinct, all of them were resistant to first generation beta lactam antibiotics tested in this study. PMID:16427154

  17. Antibiotic Resistance in Aeromonas Upstream and Downstream of a Water Resource Recovery Facility

    PubMed Central

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

    2014-01-01

    Aeromonas strains isolated from sediments upstream and downstream of a water resource recovery facility (WRRF) over a two-year time period were tested for susceptibility to thirteen antibiotics. Incidence of resistance to antibiotics, antibiotic resistance phenotypes, and diversity (based on resistance phenotypes) were compared in the two populations. At the beginning of the study, the upstream and downstream Aeromonas populations were different for incidence of antibiotic resistance (p < 0.01), resistance phenotypes (p < 0.005), and diversity. However, these differences declined over time and were not significant at the end of the study. These results (1) indicate that antibiotic resistance in Aeromonas in stream sediments fluctuates considerably over time and (2) suggest that WRRF effluent does not, when examined over the long term, affect antibiotic resistance in Aeromonas in downstream sediment. PMID:25327024

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

    EPA Science Inventory

    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...

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

    PubMed Central

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

    PubMed

    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. Bundle-forming pilus locus of Aeromonas veronii bv. Sobria.

    PubMed

    Hadi, Nahal; Yang, Qin; Barnett, Timothy C; Tabei, S Mohammed B; Kirov, Sylvia M; Shaw, Jonathan G

    2012-04-01

    Little is known about the colonization mechanisms of Aeromonas spp. Previous work has suggested that the type IV bundle-forming pilus (Bfp) is an aeromonad intestinal colonization factor. This study provides the first genetic characterization of this structure. To define the role of Bfp in Aeromonas veronii bv. Sobria adherence, a 22-kb locus encoding the bundle-forming pilus was isolated; this contained 17 pilus-related genes similar to the mannose-sensitive hemagglutinin (MSHA) of Vibrio cholerae. Reverse transcriptase PCR (RT-PCR) demonstrated that the locus had two major transcriptional units, mshI to mshF and mshB to mshQ. Transcriptional fusion experiments demonstrated the presence of two strong promoters upstream of mshI and mshB. The locus encoded four putative prepilin proteins, one of which (MshA) corresponded to the N-terminal sequence of the previously isolated major pilin protein. All the pilin genes were inactivated, mutation of each minor or major pilin gene greatly reduced the bacterium's ability to adhere and form biofilms, and complementation of each mutant in trans rescued this phenotype. Mutation of the major pilin MshA and MshB, a minor pilin, resulted in their loss. The position of the mshH gene is conserved within a number of bacteria, and we have shown it is not transcriptionally linked to the other msh genes; moreover, its mutation did not have a dramatic effect on either adhesion or biofilm formation. We conclude that the bundle-forming pilus is required for A. veronii bv. Sobria adherence and biofilm formation; furthermore, both the major and minor pilin proteins are essential for this process. PMID:22311923

  2. Bundle-Forming Pilus Locus of Aeromonas veronii bv. Sobria

    PubMed Central

    Hadi, Nahal; Yang, Qin; Barnett, Timothy C.; Tabei, S. Mohammed B.; Kirov, Sylvia M.

    2012-01-01

    Little is known about the colonization mechanisms of Aeromonas spp. Previous work has suggested that the type IV bundle-forming pilus (Bfp) is an aeromonad intestinal colonization factor. This study provides the first genetic characterization of this structure. To define the role of Bfp in Aeromonas veronii bv. Sobria adherence, a 22-kb locus encoding the bundle-forming pilus was isolated; this contained 17 pilus-related genes similar to the mannose-sensitive hemagglutinin (MSHA) of Vibrio cholerae. Reverse transcriptase PCR (RT-PCR) demonstrated that the locus had two major transcriptional units, mshI to mshF and mshB to mshQ. Transcriptional fusion experiments demonstrated the presence of two strong promoters upstream of mshI and mshB. The locus encoded four putative prepilin proteins, one of which (MshA) corresponded to the N-terminal sequence of the previously isolated major pilin protein. All the pilin genes were inactivated, mutation of each minor or major pilin gene greatly reduced the bacterium's ability to adhere and form biofilms, and complementation of each mutant in trans rescued this phenotype. Mutation of the major pilin MshA and MshB, a minor pilin, resulted in their loss. The position of the mshH gene is conserved within a number of bacteria, and we have shown it is not transcriptionally linked to the other msh genes; moreover, its mutation did not have a dramatic effect on either adhesion or biofilm formation. We conclude that the bundle-forming pilus is required for A. veronii bv. Sobria adherence and biofilm formation; furthermore, both the major and minor pilin proteins are essential for this process. PMID:22311923

  3. Antibacterial action of combinations of oxytetracycline, dimethyl sulfoxide, and EDTA-tromethamine on Proteus, Salmonella, and Aeromonas.

    PubMed

    Wooley, R E; Gilbert, J P; Shotts, E B

    1982-01-01

    Antibacterial effects against Proteus mirabilis, Salmonella typhimurium, and Aeromonas hydrophila were obtained with subminimal inhibitory concentrations of oxytetracycline and EDTA-tromethamine. Antibacterial effects were not observed with subminimal inhibitory concentrations of dimethyl sulfoxide plus oxytetracycline or with dimethyl sulfoxide plus EDTA-tromethamine. Using a 2-dimensional Microtiter checkerboard technique, inhibitory activities of the various combinations of solutions were studied, and isobolograms were plotted. A synergistic effect was seen with combinations of oxytetracycline and EDTA-tromethamine. The greatest synergistic effect was observed when the mixture was caused to react with P mirabilis. These findings were confirmed by kinetic studies of microbial death, using one-fourth minimal inhibitory concentrations of these preparations. PMID:6807142

  4. Characterization of Aeromonas spp. isolated from humans with diarrhea, from healthy controls, and from surface water in Bangladesh.

    PubMed Central

    Kühn, I; Albert, M J; Ansaruzzaman, M; Bhuiyan, N A; Alabi, S A; Islam, M S; Neogi, P K; Huys, G; Janssen, P; Kersters, K; Möllby, R

    1997-01-01

    Aeromonas isolates from patients with diarrhea in Bangladesh (n = 69), from healthy controls (n = 11), and from surface water (n = 40) were analyzed with respect to their hybridization groups (HGs) by the aid of fatty acid methyl ester (FAME) characterization and DNA fingerprinting by AFLP, biochemical phenotypes (Phe-nePlate [PhP] types), and the production of hemolysin and cytotoxin. The aim of the investigation was to find out whether certain strains carrying virulence factors predominated among patient isolates. According to FAME and/or AFLP analysis, most human isolates were allocated to DNA HGs 4 (Aeromonas caviae) and 1 (A. hydrophila). Most environmental strains were allocated to HG8 (A. veronii biogroup sobria) and HG4 (A. caviae), and only one was of HG1. According to PhP typing, the diversity among patient isolates was lower than that among other strains, and two dominating PhP types (types BD-1 and BD-2) were identified in 29 and 30% of the patient isolates, respectively. PhP type BD-1 was also common among the environmental isolates, whereas PhP type BD-2 was only identified in two of the other isolates. Twenty-five of 26 isolates belonging to HG1 were of the same PhP type (BD-2), whereas isolates of other common HGs were more diverse according to their PhP types. Hemolytic and cytotoxin-producing strains occurred more frequently among the environmental isolates than among patient isolates. However, the hemolytic and cytotoxic activities among human isolates was strongly correlated to the HG1/BD-2 type, which, in addition, showed high cytotoxin titers (median values, 1/512 compared to 1/128 for cytotoxin-positive isolates belonging to other types). Thus, the HG1/BD-2 type may represent a pathogenic A. hydrophila type that is able to produce diarrhea in humans. PMID:9003598

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

    PubMed Central

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

    2015-01-01

    The pigmentation of many Aeromonas species has been thought to be due to the production of a L-DOPA (L-3,4-dihydroxyphenylalanine) based melanin. However, in this study we found that although L-DOPA synthesis occurs in the high-melanin-yielding Aeromonas media strain WS, it plays a minor, if any, role in pigmentation. Instead, the pigmentation of A. media strain WS is due to the production of pyomelanin through HGA (homogentisate). Gene products of phhA (encodes phenylalanine hydroxylase), tyrB and aspC (both encode aromatic amino acid aminotransferase), and hppD (encodes 4-hydroxyphenylpyruvate dioxygenase) constitute a linear pathway of converting phenylalanine to HGA and disruption of any one of these genes impairs or blocks pigmentation of A. media strain WS. This HGA biosynthesis pathway is widely distributed in Aeromonas, but HGA is only detectable in the cultures of pigmented Aeromonas species. Heterologous expression of HppD from both pigmented and non-pigmented Aeromonas species in E. coli leads to the production of pyomelanin and thus pigmentation, suggesting that most Aeromonas species have the critical enzymes to produce pyomelanin through HGA. Taken together, we have identified a widely conserved biosynthesis pathway of HGA based pyomelanin in Aeromonas that may be responsible for pigmentation of many Aeromonas species. PMID:25793756

  6. CHARACTERIZATION OF PRECURSOR 165 RRNA FOR AEROMONAS HYDROPHILA

    EPA Science Inventory

    Current strategies for monitoring drinking water quality involve culture-based methods to detect the presence of microbial indicators. However, these methods are insensitive when the organisms have undergone physiological changes such as injury and starvation that can occur in h...

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

    PubMed

    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

  8. Hydroxamate-induced spectral perturbations of cobalt Aeromonas aminopeptidase.

    PubMed

    Wilkes, S H; Prescott, J M

    1987-06-25

    The absorption spectrum of cobalt(II)-substituted Aeromonas aminopeptidase is markedly perturbed by the presence of equimolar concentrations of D-amino acid hydroxamates and acyl hydroxamates that have previously been shown to be powerful inhibitors of this enzyme (Wilkes, S. H., and Prescott, J. M. (1983) J. Biol. Chem. 258, 13517-13521). D-Valine hydroxamate produces the most distinctive perturbation, splitting the characteristic 527 nm absorption peak of the cobalt enzyme to form peaks at 564, 520, and 487 nm with molar extinction values of 126, 98, and 67 M-1 cm-1, respectively. A qualitatively similar perturbation, albeit with lower extinction values, results from the addition of D-leucine hydroxamate, whereas D-alanine hydroxamate perturbs the spectrum, but does not evoke the peak at 564 nm. In contrast, hydroxamates of L-valine and L-leucine in concentrations equi-molar to that of the enzyme produce only faint indications of change in the spectrum, but the hydroxamates of several other L-amino acids perturb the spectrum essentially independently of the identity of the side chain and in a qualitatively different manner from that of D-valine hydroxamate and D-leucine hydroxamate. At the high enzyme:substrate ratios used in the spectral experiments, L-leucine hydroxamate and L-valine hydroxamate proved to be rapidly hydrolyzed, hence their inability to perturb the spectrum of the cobalt-substituted enzyme during the time course of a spectral experiment. Values of kcat for L-amino acid hydroxamates, all of which are good reversible inhibitors of the hydrolysis of L-leucine-p-nitroanilide by Aeromonas aminopeptidase, were found to range from 0.01 min-1 to 5.6 min-1 for the native enzyme and from 0.27 min-1 to 108 min-1 for the cobalt-substituted enzyme; their km values toward the cobalt aminopeptidase range from 1.2 X 10(-7) M to 1.9 X 10(-5) M. The mutual exclusivity of binding for hydroxamate inhibitors and 1-butaneboronic acid, previously shown by kinetics

  9. Lectin-binding properties of Aeromonas caviae strains

    PubMed Central

    Rocha-de-Souza, Cláudio M.; Hirata-Jr, Raphael; Mattos-Guaraldi, Ana L.; Freitas-Almeida, Angela C.; Andrade, Arnaldo F. B.

    2008-01-01

    The cell surface carbohydrates of four strains of Aeromonas caviae were analyzed by agglutination and lectin-binding assays employing twenty highly purified lectins encompassing all sugar specificities. With the exception of L-fucose and sialic acid, the sugar residues were detected in A. caviae strains. A marked difference, however, in the pattern of cell surface carbohydrates in different A. caviae isolates was observed. Specific receptors for Tritricum vulgaris (WGA), Lycopersicon esculentum (LEL) and Solanum tuberosum (STA) (D-GlcNAc-binding lectins) were found only in ATCC 15468 strain, whereas Euonymus europaeus (EEL, D-Gal-binding lectin) sites were present exclusively in AeQ32 strain, those for Helix pomatia (HPA, D-GalNAc-binding lectin) in AeC398 and AeV11 strains, and for Canavalia ensiformes (Con A, D-Man-binding lectin) in ATCC 15468, AeC398, AeQ32 and AeV11 strains, after bacterial growing at 37°C. On the other hand, specific receptors for WGA and EEL were completely abrogated growing the bacteria at 22°C. Binding studies with 125I- labeled lectins from WGA, EEL and Con A were performed. These assays essentially confirmed the selectivity, demonstrated in the agglutination assays of these lectins for the A. caviae strains. PMID:24031204

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

    PubMed

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

    2015-09-01

    The genus Aeromonas comprises primarily aquatic bacteria and also serious human and animal pathogens with the occurrence in clinical material, drinking water, and food. Aeromonads are typical for their complex taxonomy and nomenclature and for limited possibilities of identification to the species level. According to studies describing the use of MALDI-TOF MS in diagnostics of aeromonads, this modern chemotaxonomical approach reveals quite high percentage of correctly identified isolates. We analyzed 64 Aeromonas reference strains from the set of 27 species. After extending the range of analyzed Aeromonas species by newly described ones, we proved that MALDI-TOF MS procedure accompanied by Biotyper tool is not a reliable diagnostic technique for aeromonads. We obtained quite high percentage of false-positive, incorrect, and uncertain results. The identification of newly described species is accompanied with misidentifications that were observed also in the case of pathogenic aeromonads. PMID:25520239

  11. Inhibition of Microcystis aeruginosa by the extracellular substances from an Aeromonas sp.

    PubMed

    Liu, Yu-Mei; Chen, Ming-Jun; Wang, Meng-Hui; Jia, Rui-Bao; Li, Li

    2013-09-28

    Growth of Microcystis aeruginosa could be inhibited significantly within 24 h by the extracellular substances prepared from Aeromonas sp. strain FM. During the treatment, the concentration of extracellular soluble carbohydrates increased significantly in algal culture. Morphological and ultrastructural changes in M. aeruginosa cells, including breakage of the cell surface, secretion of mucilage, and intracellular disorganization of thylakoids, were observed. HPLC-MS analysis showed that the extracellular substances of Aeromonas sp. strain FM were a mixture of free amino acids, tripeptides, and clavulanate. Among these, the algae-lysis effects of lysine and clavulanate were confirmed. PMID:23727796

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

    PubMed

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

    2015-05-01

    We aimed to document the risk of Aeromonas spp. in marine shrimp species cultured in inland low salinity ponds in Thailand. In 14 of 18 shrimp samples retrieved from inland grow-up ponds, Aeromonas spp. were detected at ranges from 4667 to 1,500,000 CFU/g body weight. The phylogenetic tree constructed with the gyrB and cpn60 concatenated sequences indicated that the 87 isolates consisted of Aeromonas veronii (70%), Aeromonas aquariorum (18%), Aeromonas caviae (7%), Aeromonas jandaei (2%), and Aeromonas schubertii (2%). The potential virulence of the isolates was examined by phenotypic and PCR assays. Hemolytic activity and the extracellular activity of lipase, DNase, and gelatinase were observed in most isolates (94-99%). PCR revealed the presence of 9 genes related to virulence in the 87 isolates: act (75%), aer (74%), alt (30%), ast (1%), ascV (34%), aexT (24%), fla (92%), ela (34%), and lip (24%). The susceptibility profiles to 14 antimicrobial agents of isolates were typical for the genus, but resistance to cefotaxime, a third-generation cephalosporin, and imipenem were found in two A. aquariorum and in three A. veronii isolates, respectively. These resistances were confirmed by determining minimum inhibitory concentrations. Our results indicate that the microbiological risk posed by Aeromonas should be considered for marine shrimp species that are cultured in low-salinity ponds. These shrimps may also be a vehicle for the transfer of different genotypes of Aeromonas and antibiotic-resistant determinants to regions worldwide through trade. PMID:25583334

  13. Properties of Hemolysin and Protease Produced by Aeromonas trota

    PubMed Central

    Takahashi, Eizo; Ozaki, Haruka; Fujii, Yoshio; Kobayashi, Hidetomo; Yamanaka, Hiroyasu; Arimoto, Sakae; Negishi, Tomoe; Okamoto, Keinosuke

    2014-01-01

    We examined the properties of exotoxins produced by Aeromonas trota (A. enteropelogenes), one of the diarrheagenic species of Aeromonadaceae. Nine of 19 A. trota isolates that grew on solid media containing erythrocytes showed hemolytic activity. However, the hemolytic activities of the culture supernatants of these hemolytic strains of A. trota were markedly lower than those of A. sobria when cultured in liquid medium, and the amount of hemolysin detected by immunoblotting using antiserum against the hemolysin produced by A. sobria was also low. A mouse intestine loop assay using living bacterial cells showed that A. trota 701 caused the significant accumulation of fluid, and antiserum against the hemolysin produced suppressed the enterotoxic action of A. trota 701. These results indicated that A. trota 701 was diarrheagenic and the hemolysin produced was the causative agent of the enterotoxic activity of A. trota. The hemolysin in A. sobria was previously shown to be secreted in a preform (inactive form) and be activated when the carboxy-terminal domain was cleaved off by proteases in the culture supernatant. Since mature hemolysin was detected in the culture supernatants of A. trota, we analyzed the extracellular protease produced by A. trota. Fifteen of 19 A. trota isolates that grew on solid media containing skim milk showed proteolytic activity. We subsequently found that most A. trota isolates possessed the serine protease gene, but not the metalloprotease gene. Therefore, we determined the nucleotide sequence of the serine protease gene and its chaperone A. trota gene. The results obtained revealed that the deduced amino acid sequences of serine protease and the chaperone were homologous to those of A. sobria with identities of 83.0% and 75.8%, respectively. PMID:24633045

  14. Surface phenotypic characteristics and virulence of Spanish isolates of Aeromonas salmonicida after passage through fish.

    PubMed Central

    Fernández, A I; Pérez, M J; Rodríguez, L A; Nieto, T P

    1995-01-01

    Eleven strains of Aeromonas salmonicida were passaged twice by intraperitoneal injection through rainbow trout and reisolated from the kidney of moribund fish. The surface characteristics and virulence of the strains changed following passage through fish. None of the in vitro tests used could effectively predict the in vivo virulence. PMID:7646039

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

    EPA Science Inventory

    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...

  16. VIRULENCE FACTORS OF AEROMONAS: A GENETIC CHARACTERIZATION OF DRINKING WATER ISOLATES

    EPA Science Inventory

    A survey of finished drinking water conducted by the US EPA during 2000-2001, revealed that 8 out of 18 water utilities encompassing several states (NY, KY, IA, OH) were contaminated with aeromonas species. Altogether 205 organisms were isolated by EPA method 1601. All of the ...

  17. Detection of the causative agent of furunculusis, Aeromonas salmonicida in salmonids of the Krka River.

    PubMed

    Kapetanović, D; Vardić, I; Kurtović, B; Valić, D; Teskeredzić, E

    2008-02-01

    In this paper we describe the bacterial community associated with salmonids from the Krka River. Diversity analysis demonstrated that majority of the recovered bacteria were related to Aeromonadaceae group. Bacterial analysis also revealed the presence of Shigella spp. and Pseudomonas fluorescens. Isolation of Aeromonas salmonicida from trout, presents first isolation of this bacteria Croatian rivers. PMID:17624808

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

    PubMed

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

    2015-01-01

    Storage in ice is a common way of preserving commercial fish species but some microorganisms can still contaminate and participate in the spoilage of the product; therefore, identification of potential harmful microbes is important. Thirteen colonies were isolated from common carp (Cyprinus carpio) that had been stored in ice, whose phenotypic identification revealed that they belonged to the genera Aeromonas (n = 5) and Shewanella (n = 8). Molecular genotyping with ERIC-PCR showed clonality only among two of the five Aeromonas isolates and for two groups (n = 3; n = 2) of the eight Shewanella isolates. Sequencing the rpoD gene showed that four Aeromonas isolates belonged to the species Aeromonas salmonicida and one to A. sobria. Of the eight Shewanella, seven isolates cluster with Shewanella putrefaciens and one with Shewanella profunda in the 16S rRNA phylogenetic tree. However, analysis of the gyrB gene showed that these eight isolates could constitute a new species closely related to S. baltica. The Shewanella and A. salmonicida isolates produce off-odours and reduce trimethylamine oxide, indicating that they might contribute to the spoilage of the fish. PMID:25790506

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

    PubMed Central

    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 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. PMID:22927788

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

    PubMed

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

    2015-03-01

    In vitro and in vivo activity of the Lippia alba essential oil (EO) against Aeromonas sp. was evaluated. In the in vitro assay the minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of EO for Aeromonas cells were determined using the microdilution method. Twenty five strains of Aeromonas sp. isolated from infected fish obtained from local fish farms were used. MIC and MBC values were 2862 and 5998 µg mL-1 for L. alba EO and 0.5 and 1.2 µg mL-1 for gentamicin, respectively. In the in vivo assay silver catfish juveniles (Rhamdia quelen) (7.50 ± 1.85 g and 10.0 ± 1.0 cm) with typical injuries associated to Aeromonas infection were divided into four treatments (in triplicate n=10): untreated fish (negative control), 10 mg L-1 of gentamicin, and 20 or 50 µL L-1 of EO. Fish were maintained in aerated 20 L plastic boxes. After 10 days survival of silver catfish infected with Aermonas sp. and treated with essential oil (50 µL L-1) was greater than 90%. PMID:25789790

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

    PubMed

    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

  2. Functional Characterization of Type IV Pili Expressed on Diarrhea-Associated Isolates of Aeromonas species

    PubMed Central

    Kirov, Sylvia M.; O’Donovan, Lisa A.; Sanderson, Kevin

    1999-01-01

    Our past work has shown that long, flexible type IV pili (single or in bundles) are the predominant pili expressed on fecal isolates of diarrhea-associated species of Aeromonas (Aeromonas veronii biovar sobria and A. caviae). They represent a family of type IV pili which we have designated Bfp (for bundle-forming pili). Reports from Japan suggest that Bfp are intestinal colonization factors. This study presents compelling evidence to support this conclusion. Aeromonas bacteria and/or Bfp purified from a strain of A. veronii biovar sobria were shown to adhere to epithelial and intestinal cell lines, freshly isolated human enterocytes, and fresh and fixed human and rabbit intestinal tissues, as determined by light and electron microscopy and immunohistochemical detection. Removal of Bfp by mechanical means decreased adhesion to cell lines by up to 80%. Purified Bfp blocked adhesion of the test strain to intestinal cells in a dose-dependent manner. Adhesion was also blocked by the Fab fraction of anti-Bfp immunoglobulin G. Moreover, ultrastructural studies (ruthenium red staining and transmission and scanning electron microscopy) demonstrated for the first time that Aeromonas adhesion to human enterocytes is pilus mediated and suggested that Bfp may also promote colonization by forming bacterium-to-bacterium linkages. Bfp-positive isolates examined for type IV pilus-mediated twitching motility in agar and slide culture assays developed for Pseudomonas aeruginosa did not, however, exhibit this function. PMID:10496928

  3. An in-house multiplex pcr method to detect of putative virulence factors in aeromonas species

    PubMed Central

    Aguilera-Arreola, Ma. Guadalupe; Martínez, Alma Aidee Carmona; Castro-Escarpulli, Graciela

    2011-01-01

    A pentaplex PCR was developed and optimised to detect the genes that encode the five most important putative virulence factors in Aeromonas isolates. It seems to be more efficient than previously reported techniques and promises to be a powerful tool for more accurate risk assessments and for monitoring pathogenic strains. PMID:24031758

  4. Prevalence, characterization, and antimicrobial resistance of Aeromonas strains from various retail food products in Mumbai, India.

    PubMed

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

    2011-09-01

    A total of 154 food samples (chicken, fish, and ready-to-eat sprouts) from various retail outlets in Mumbai, India, were analyzed for the presence of Aeromonas spp. over a period of 2 y (January 2006 to March 2008). Twenty-two Aeromonas isolates belonging to 7 different species were isolated from 18 (11.7%) food samples. The highest percentages of isolation were from chicken (28.6%) followed by fish (20%) and sprout (2.5%) samples. Aeromonas caviae, A. veronii bv. sobria, and A. salmonicida were the most frequently isolated species from sprouts, chicken, and fish samples, respectively. The genes encoding for putative virulence factors, cytotoxic enterotoxin (act), hemolysin (hly), aerolysin (aer), elastase (ahyB), and lipase (lip) were detected using polymerase chain reaction method in 59.1%, 40.9%, 22.7%, 54.5%, and 31.8% of the strains, respectively. The isolated Aeromonas strains were found to be positive for virulence factors, that is, amylase, DNase, gelatinase, protease, and lipase production. More than 60% isolates were also positive for β-hemolytic activity. All these food isolates were found to be resistant to ampicillin and bacitracin, and sensitive to gentamicin, 3rd-generation cephalosporins (ceftazidime, cephotaxime, ceftriaxone), and chloramphenicol. Seventeen (77.2%) isolates harbored single and/or multiple plasmids (approximately 5 to >16 kb). The XbaI digestion patterns of chromosomal DNA of these isolates, using pulsed field gel electrophoresis, showed high genetic diversity among these isolates. Our results demonstrate the presence of various Aeromonas spp. with virulence potential and antimicrobial resistance in different food products marketed in Mumbai, India. The potential health risks posed by consumption of these raw or undercooked food products should not be underestimated. PMID:21824136

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

    PubMed

    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

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

    PubMed

    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

  7. Physical and functional S-layer reconstitution in Aeromonas salmonicida.

    PubMed Central

    Garduño, R A; Phipps, B M; Kay, W W

    1995-01-01

    The various functions attributed to the S-layer of Aeromonas salmonicida have been previously identified by their conspicuous absence in S-layer-defective mutants. As a different approach to establish the multifunctional nature of this S-layer, we established methods for reconstitution of the S-layer of A. salmonicida. Then we investigated the functional competence of the reconstituted S-layer. S-layers were reconstituted in different systems: on inert membranes or immobilized lipopolysaccharide (LPS) from purified S-layer protein (A-protein) or on viable cells from either A-protein or preassembled S-layer sheets. In the absence of divalent cations and LPS, purified A-protein in solution spontaneously assembled into tetrameric oligomers and, upon concentration by ultrafiltration, into macroscopic, semicrystalline sheets formed by oligomers loosely organized in a tetragonal arrangement. In the presence of Ca2+, purified A-protein assembled into normal tetragonal arrays of interlocked subunits. A-protein bound with high affinity (Kd, 1.55 x 10(-7) M) and specificity to high-molecular-weight LPS from A. salmonicida but not to the LPSs of several other bacterial species. In vivo, A-protein could be reconstituted only on A. salmonicida cells which contained LPS, and Ca2+ affected both a regular tetragonal organization of the reattached A-protein and an enhanced reattachment of the A-protein to the cell surface. The reconstitution of preformed S-layer sheets (produced by an S-layer-secreting mutant) to an S-layer-negative mutant occurred consistently and efficiently when the two mutant strains were cocultured on calcium-replete solid media. Reattached A-protein (exposed on the surface of S-layer-negative mutants) was able to bind porphyrins and an S-layer-specific phage but largely lacked regular organization, as judged by its inability to bind immunoglobulins. Reattached S-layer sheets were regularly organized and imparted the properties of porphyrin binding

  8. Aeromonas sobria necrotizing fasciitis and sepsis in an immunocompromised patient: a case report and review of the literature

    PubMed Central

    2014-01-01

    Introduction Aeromonas veronii biovar sobria is a rare cause of bacteremia, with several studies indicating that this isolate may be of particular clinical significance since it is enterotoxin producing. A wide spectrum of infections has been associated with Aeromonas species in developing countries that include gastroenteritis, wound infections, septicemia and lung infections. This infection, caused by Aeromonas species, is usually more severe in immunocompromised than immunocompetent individuals. We here describe a case of soft tissue infection and severe sepsis due to Aeromonas sobria in an immunocompromised patient. Case presentation A 74-year-old Caucasian man with a clinical history of chronic lymphocytic leukemia and immune thrombocytopenia, periodically treated with steroids, was admitted to our Intensive Care Unit because of necrotizing fasciitis and multiorgan failure due to Aeromonas sobria, which resulted in his death. The unfortunate coexistence of a Candida albicans infection played a key role in the clinical course. Conclusion Our experience suggests that early recognition and aggressive medical and surgical therapy are determinants in the treatment of severe septicemia caused by an Aeromonas sobria in an immunocompromised patient. PMID:25245365

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

    PubMed Central

    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. Aeromonas schubertii, a new mannitol-negative species found in human clinical specimens.

    PubMed

    Hickman-Brenner, F W; Fanning, G R; Arduino, M J; Brenner, D J; Farmer, J J

    1988-08-01

    In 1983 the vernacular name Enteric Group 501 was coined for a group of strains that had been referred to our laboratory as "possible Vibrio damsela that does not require NaCl for growth." By DNA-DNA hybridization (hydroxyapatite method, 32P, 60 and 75 degrees C), six strains of Enteric Group 501 were closely related to the labeled strain 2446-81 (70 to 95% at 60 degrees C and 71 to 93% at 75 degrees C; 0 to 1% divergence). Type strains of all Aeromonas species and reference strains of six other Aeromonas DNA hybridization groups were 26 to 42% related (60 degrees C) to strain 2446-81, but type strains of 27 Vibrio and Photobacterium species, including V. damsela, were 0 to 1% (75 degrees C) related. We propose the name Aeromonas schubertii for the highly related group of seven strains formerly known as Enteric Group 501. The type strain is designated as ATCC 43700 (CDC 2446-81). Strains of A. schubertii grew well at 36 degrees C and had positive reactions at this temperature for methyl red, Voges-Proskauer (1% NaCl, Coblentz method), lysine decarboxylase, arginine dihydrolase, motility, lipase, DNase, nitrate reduction to nitrite, oxidase, and growth in nutrient broth with 0 and 1% NaCl. There was no growth in 6% NaCl or on thiosulfate-citrate-bile salts-sucrose agar. The following sugars were fermented: D-glucose, D-galactose, maltose, D-mannose, and trehalose. The following sugars were not fermented: adonitol, L-arabinose, D-arabitol, cellobiose, dulcitol, erythritol, myo-inositol, lactose, D-mannitol, melibiose, alpha-CH3-D-glucoside, raffinose, L-rhamnose, salicin, D-sorbitol, sucrose, and D-xylose. Esculin was not hydrolyzed, and the string test was negative. The mannitol-negative reaction differtiates A. schubertii from other Aeromonas species. The antibiogram of this organism is typical of other Aeromonas strains (resistance to ampicillin and carbenicillin and susceptibility to most other agents). A. schubertii strains have been isolated from abscesses (two

  11. 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

    EPA Science Inventory

    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., ...

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

    SciTech Connect

    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.

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

    PubMed

    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

  14. Isolation of Aeromonas salmonicida from Human Blood Sample: A Case Report.

    PubMed

    Tewari, Rachna; Dudeja, Mridu; Nandy, Shyamasree; Das, Ayan Kumar

    2014-02-01

    Aeromonas salmonicida belonging to the genus Aeromonas, is a common pathogen that causes furunculosis and septicaemia in variety of fishes. It infects cold blooded vertebrates living at low temperatures mainly salmonid fish hence named salmonicida. Untill recently Aeromanas salmonicida is considered to be a fish pathogen. A. salmonicida is considered to be non-pathogenic for humans as it cannot grow at 37ºC. "However, In our laboratory culture plates and broths were incubated twice at 37ºC and each time same type of colonies were isolated which were identified as A. samonicida by Vitek 2 compact system bioMerieux, Inc. (Durham, N.C.)". By far no report has been received regarding its isolation from humans biological sample. Here we present the first report of A. salmonicida isolated from the human blood. PMID:24701507

  15. Characterization of Aeromonas caviae antigens which cross-react with Shigella boydii 5.

    PubMed Central

    Albert, M J; Qadri, F; Ansaruzzaman, M; Kibriya, A K; Haider, K; Neogi, P K; Alam, K; Alam, A N

    1992-01-01

    Live and boiled cells of 16 strains of Aeromonas caviae, isolated from patients with diarrhea, agglutinated with Shigella boydii 5 antiserum in a slide test. Further studies with seven selected strains showed agglutination with boiled cells in a tube test. Lipopolysaccharide antigen extracted from one of these strains cross-reacted with S. boydii 5 in enzyme-linked immunosorbent assay and immunoblot studies. Either all or the majority of the seven strains possessed properties deemed to be diarrheagenic. Images PMID:1583145

  16. Precipitating antibody against Aeromonas salmonicida in serums of inbred albino Rainbow Trout (Salmo gairdneri)

    USGS Publications Warehouse

    Anderson, Douglas P.; Klontz, George W.

    1970-01-01

    Precipitins in albino rainbow trout serums were demonstrated by gel diffusion after a single parenteral exposure to the soluble antigens of Aeromonas salmonicida. The fraction of the serum containing antibody activity against the presented antigens was shown by immunoelectrophoresis to be in the nonmigrating region. This corresponded to the beta-2 fraction of rabbit serum. An antibody-containing component comparable with rabbit gamma globulin was not detected.

  17. Natural transformation as a mechanism of horizontal gene transfer among environmental Aeromonas species.

    PubMed

    Huddleston, Jennifer R; Brokaw, Joshua M; Zak, John C; Jeter, Randall M

    2013-06-01

    Aeromonas species are common inhabitants of aquatic environments and relevant as human pathogens. Their potential as pathogens may be related in part to lateral transfer of genes associated with toxin production, biofilm formation, antibiotic resistance, and other virulence determinants. Natural transformation has not been characterized in aeromonads. DNA from wild-type, prototrophic strains that had been isolated from environmental sources was used as donor DNA in transformation assays with auxotrophs as the recipients. Competence was induced in 20% nutrient broth during the stationary phase of growth. Optimal transformation assay conditions for one chosen isolate were in Tris buffer with magnesium or calcium, pH 5-8, and a saturating concentration of 0.5 μg of DNA per assay (3.3 ng of DNA μl⁻¹) at 30°C. Sodium was also required and could not be replaced with ammonium, potassium, or lithium. The maximal transformation frequency observed was 1.95 × 10⁻³ transformants (recipient cell)⁻¹. A survey of environmental Aeromonas auxotrophic recipients (n=37), assayed with donor DNA from other wild-type environmental aeromonads under optimal assay conditions, demonstrated that 73% were able to act as recipients, and 100% were able to act as donors to at least some other aeromonads. Three different transformation groups were identified based on each isolates' ability to transform other strains with its DNA. The transformation groups roughly corresponded to phylogenetic groups. These results demonstrate that natural transformation is a general property of Aeromonas environmental isolates with implications for the genetic structures of coincident Aeromonas populations. PMID:23541366

  18. Isolation of a pigment-producing strain of Aeromonas liquefaciens from silver salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Ross, A.J.

    1962-01-01

    Aeromonas salmonicida, the etiological agent of furunculosis in fish, is distinctive in the field of fish diseases in that it may readily be recognized by the water-soluble reddish-brown pigment formed on culture media containing tyrosine. Additional tests for the identification of this organism include blackening of the colonial growth when flooded with an aqueous solution of p-phenylenediamine and a lack of motility (Griffin, Progressive Fish Culturist 14:74, 1952).

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

    PubMed

    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

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

    PubMed Central

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

    2014-01-01

    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

  1. Prevalence and antimicrobial susceptibilities of Vibrio, salmonella, and Aeromonas isolates from various uncooked seafoods in Thailand.

    PubMed

    Woodring, Joseph; Srijan, Apichai; Puripunyakom, Paksathorn; Oransathid, Wilawan; Wongstitwilairoong, Boonchai; Mason, Carl

    2012-01-01

    Uncooked seafood samples were collected from open markets and supermarkets in Bangkok, Thailand, and were examined for the presence of Vibrio, Salmonella, and Aeromonas species from January to February 2008. From 120 samples, 272 bacterial isolates were identified through biochemical testing. Of all sea bass, shrimp, oyster, and blood cockle samples (30 of each) that were processed for culture, 114 (95%) samples had at least one detectable isolate of Vibrio, Salmonella, or Aeromonas, leaving only 6 (5%) samples free of them. All oyster sample (100%) had at least one pathogen, followed by sea bass (97%), blood cockles (97%), and shrimp (90%). Overall, 111 (92%) of all samples had detectable Vibrio spp., 32 (27%) had detectable Aeromonas spp., and 25 (21%) had detectable Salmonella enterica. There was no overall difference between positive samples collected from fresh markets versus supermarkets (relative risk, 0.97; 95% CI, 0.89 to 1.05). Resistance to ampicillin among isolated pathogens was relatively high (56%), while resistance to 12 other antibiotics, including azithromycin, ciprofloxacin, and trimethoprim-sulfamethoxazole, was relatively low (0, 0, and 3%, respectively). Study results indicate that uncooked seafood in Bangkok, Thailand, commonly harbors enteric pathogens and that consumption of uncooked seafood should be avoided to reduce foodborne illnesses. PMID:22221354

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

    USGS Publications Warehouse

    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

  3. Transient intestinal colonization by multiple phenotypes of Aeromonas species during the first week of life.

    PubMed Central

    Pazzaglia, G; Escalante, J R; Sack, R B; Rocca, C; Benavides, V

    1990-01-01

    The intestinal colonization rate of Aeromonas spp. was determined for 52 cesarean-born Peruvian neonates. Rectal swabs were obtained daily from newborns during their postdelivery hospitalization (mean = 5.5 days), and the gross appearances of their feces (blind determinations) were recorded. Aeromonas spp. were recovered from rectal swabs of 12 of 52 (23.1%) infants during their first week of life; the isolates were obtained from 5 of 9 (55.6%) infants with at least one stool with a watery consistency and from 7 of 43 (16.3%) neonates with no watery stools (P = 0.022). None of the infected infants became clinically ill. No other commonly recognized enteropathogens were detected in watery stools. An environmental survey indicated that hospital water was the probable source of infection. These and other data indicated that Aeromonas colonization occurs transiently at a very early age in Peruvian neonates and that in some instances, initial infection may be followed several days later by one or more watery stools of normal volume. PMID:2394805

  4. Aeromonas species associated with necrotizing enteritis and septicemia in an adult male ostrich (Struthio camelus).

    PubMed

    França, M; Walker, R L; Kokka, R; Shivaprasad, H L

    2009-06-01

    A deceased 10-yr-old male ostrich was diagnosed with severe necrotizing enteritis and septicemia. The bird was inappetent for 3 wk and had neurologic signs 2 days prior to death. Macroscopically, no significant lesions were noted aside from congestion of the liver, kidneys, and spleen. Histopathology revealed severe fibrinonecrotic enteritis,associated with large numbers of gram-negative bacteria, multifocal fibrinoid necrosis in portal arteries, accumulation of fibrin in hepatic sinusoids, myocardial degeneration, and necrosis. There was also squamous metaplasia in the glands of the esophagus and external ears. A gram-negative rod was isolated in pure culture from intestine, liver, lungs, and trachea and identified as an Aeromonas species. The concentration of vitamin A in the liver was extremely low. The lesions seen in the intestine and liver and the isolation of an Aeromonas sp. from various tissues strongly suggest that this bacterium was the cause of the necrotizing enteritis, septicemia, and death of this ostrich. Vitamin A deficiency might have predisposed the bird to the Aeromonas infection. PMID:19630242

  5. Simultaneous effects of environmental factors on motile Aeromonas dynamics in an urban effluent and in the natural seawater.

    PubMed

    Maalej, Sami; Mahjoubi, Amira; Elazri, Chafai; Dukan, Sam

    2003-07-01

    Seasonal dynamics of motile Aeromonas in a treated urban effluent and in natural seawater along the Sfax coast (Mediterranean sea, Tunisia) were measured over a year concurrently with seven environmental factors, and compared with those of faecal coliforms. Counts for Aeromonas from a standard plate count method, ranged from 1.48 x 10(5)CFU.100 ml(-1) to 2.2 x 10(8)CFU.100 ml(-1) in the effluent and from 7.9 x 10(3)CFU.100 ml(-1) to undetectable level in the surface marine waters. Contrary to faecal coliforms, the Aeromonas dynamics exhibited a seasonal distribution in seawater which was inverse of the seasonal distribution in the sewage: From the end of November 1998 to April 1999 (cold period), Aeromonas counts increased in the treated effluent, while it decreased very rapidly in seawater. From May to October (warm period), Aeromonas abundance decreased in the effluent but showed an increasing fluctuating trend in the marine waters with a maximum in late summer/early autumn when the temperatures were around 22-23 degrees C. Multiple correlation and regression analyses suggest, by the coefficient of determination (R(2)), that 42% of variance in Aeromonas number changes in the treated effluent, may be explained by only turbidity, radiation and Aeromonas density in the previous sample, while 37% of variance in marine ecosystem were explained by radiance and conductivity. Furthermore, the t statistics and their p values and the coefficient of partial determination (r(2)) indicated that radiance contributed the most (r(2)=0.3184, t=-3.2, p=0.0041) to the dynamics of motile Aeromonas in seawater, when combined with conductivity. The models relevant for changes in faecal coliforms abundance incorporated turbidity, radiance in the effluent and conductivity, pH, radiance, turbidity in coastal marine environment. These models explain 66% and 73% of the observed cell number fluctuation, with turbidity (r(2)=0.529, t=5.08, p=0.0001) and conductivity (r(2)=0.5407, t=4.97, p=0

  6. Development and application of real-time PCR assays for quantifying total and aerolysin gene-containing aeromonas in source, intermediate, and finished drinking water.

    PubMed

    Yu, Chang-Ping; Farrell, Sara K; Robinson, Bruce; Chu, Kung-Hui

    2008-02-15

    Aeromonas spp., opportunistic pathogens, are listed as a microbiological contaminant on the Environmental Protection Agency's (EPA) Drinking Water Contaminant Candidate List. Culture-based methods for identification and quantification of Aeromonas in drinking water are time-consuming and often fail to differentiate pathogenic species from nonpathogenic ones. This study reports successful development and applications of two real-time PCR assays, based on 16S rRNA gene sequences and a virulence gene (aerolysin gene), for rapid and effective quantification of total and aerolysin gene-containing Aeromonas spp. The assays successfully quantified total and aerolysin gene-containing Aeromonas in source, intermediate, and finished water samples collected from seven water works and one pilot plant. The effectiveness of Aeromonas removal by different drinking water treatment processes was examined by comparing the results obtained from the EPA culture-based method and developed real-time PCR assays. Regardless of the methods, our results indicated that conventional water treatment combination (prechlorination/ coagulation/sedimentation/rapid sand filtration) and membrane filtration alone could effectively remove Aeromonas. Slow sand filtration alone might not be effective. The removal efficiencies by different disinfection treatments were not determined, due to the lack of detectable Aeromonas. No Aeromonas was detected in samples with turbidity below 0.06 NTU. PMID:18351092

  7. Predicting Virulence of Aeromonas Isolates Based-on Changes in Transcription of c-jun and c-fos in Human Tissue Culture Cells

    EPA Science Inventory

    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 ...

  8. Two novel temperate bacteriophages co-existing in Aeromonas sp. ARM81 - characterization of their genomes, proteomes and DNA methyltransferases.

    PubMed

    Dziewit, Lukasz; Radlinska, Monika

    2016-08-01

    Aeromonas species are causative agents of a wide spectrum of diseases in animals and humans. Although these bacteria are commonly found in various environments, little is known about their phages. Thus far, only one temperate Aeromonas phage has been characterized. Whole-genome sequencing of an Aeromonas sp. strain ARM81 revealed the presence of two prophage clusters. One of them is integrated into the chromosome and the other was maintained as an extrachromosomal, linear plasmid-like prophage encoding a protelomerase. Both prophages were artificially and spontaneously inducible. We separately isolated both phages and compared their genomes with other known viruses. The novel phages show no similarity to the previously characterized Aeromonas phages and might represent new evolutionary lineages of viruses infecting Aeromonadaceae. Apart from the comparative genomic analyses of these phages, complemented with their structural and molecular characterization, a functional analysis of four DNA methyltransferases encoded by these viruses was conducted. One of the investigated N6-adenine-modifying enzymes shares sequence specificity with a Dam-like methyltransferase of its bacterial host, while another one is non-specific, as it catalyzes adenine methylation in various sequence contexts. The presented results shed new light on the diversity of Aeromonas temperate phages. PMID:27184451

  9. Differentiation of Aeromonas isolated from drinking water distribution systems using matrix-assisted laser desorption/ionization-mass spectrometry.

    PubMed

    Donohue, Maura J; Best, Jennifer M; Smallwood, Anthony W; Kostich, Mitchell; Rodgers, Mark; Shoemaker, Jody A

    2007-03-01

    The genus Aeromonas is one of several medically significant genera that have gained prominence due to their evolving taxonomy and controversial role in human diseases. In this study, matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was used to analyze the whole cells of both reference strains and unknown Aeromonas isolates obtained from water distribution systems. A library of over 45 unique m/z signatures was created from 40 strains that are representative of the 17 recognized species of Aeromonas, as well as 3 reference strains from genus Vibrio and 2 reference strains from Plesiomonas shigelloides. The library was used to help speciate 52 isolates of Aeromonas. The environmental isolates were broken up into 2 blind studies. Group 1 contained isolates that had a recognizable phenotypic profile and group 2 contained isolates that had an atypical phenotypic profile. MALDI-MS analysis of the water isolates in group 1 matched the phenotypic identification in all cases. In group 2, the MALDI-MS-based determination confirmed the identity of 18 of the 27 isolates. These results demonstrate that MALDI-MS analysis can rapidly and accurately classify species of the genus Aeromonas, making it a powerful tool especially suited for environmental monitoring and detection of microbial hazards in drinking water. PMID:17269751

  10. Temperate bacteriophage {phi}O18P from an Aeromonas media isolate: Characterization and complete genome sequence

    SciTech Connect

    Beilstein, Frauke

    2008-03-30

    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 {phi}O18P was induced from the Aeromonas media isolate O18. {phi}O18P belongs to the Myoviridae phage family. The complete nucleotide sequence of the double stranded DNA genome of bacteriophage {phi}O18P consists of 33,985 bp. The genome has 5' protruding cohesive ends of 16 bases. On the {phi}O18P 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.

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

    PubMed

    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

  12. Historical record of Yersinia ruckeri and Aeromonas salmonicida among sea-run Atlantic salmon (Salmo salar) in the Penobscot River

    USGS Publications Warehouse

    Cipriano, R.C.; Coll, J.

    2005-01-01

    Despite restoration efforts, only about 2,000 Atlantic salmon (Salmo salar) salmon have annually returned to New England Rivers and more than 71% of these fish migrate to the Penobscot River alone. This report provides a historical compilation on the prevalence's of both Yersinia ruckeri, cause of enteric redmouth disease, and Aeromonas salmonicida, cause of furunculosis, among mature sea-run Atlantic salmon that returned to the Penobscot River from 1976 to 2003. Aeromonas salmonicida was detected in 28.6% and Yersinia ruckeri was detected among 50% of the yearly returns. Consequently, Atlantic salmon that return to the river are potential reservoirs of infection.

  13. Ribosomal Multi-Operon Diversity: An Original Perspective on the Genus Aeromonas

    PubMed Central

    Roger, Frédéric; Lamy, Brigitte; Jumas-Bilak, Estelle; Kodjo, Angeli; F., Carmagnol; E., Chachaty; C., Alba-Sauviat; C., Auvray; D., Barraud; Z., Benseddik; A., Bertrou; F., Bessis; H., Biessy; V., Blanc; Y., Boucaud-Maitre; P., Brunet; A., Michel; B., Cancet; J., Carrere; A., Cecille; G., Chambreuil; P., Chantelat; H., Chardon; C., Charrel; H., De Montclos; J.W., Decousser; J. M., Delarbre; A., Gravet; D., Deligne; C., Denoix; J., Deregnaucourt; F., Desroys du Roure; S., Dubourdieu; Z., El Harrif; C., Eloy; A., Evers; C., Febvre; D., Fevre; S., Gabriel; M. J., Galanti; E., Garnotel; M., Gavignet; F., Geffroy; G., Grise; I., Gros; I., Hermes; J., Heurte; E., Heusse; D., Jan; E., Jaouen; S., Laluque; R., Lamarca; Laurens, E.; A., Le Coustumier; E., Lecaillon; C., Lemble; M., Leneveu; S., Leotard; M. N., Letouzey; C., Malbrunot; O., Menouni; M., Morel; C., Olive; B., Pangon; J. G., Paul; J. M., Perez; P., Pouedras; D., Pressac; R., Sanchez; Y., Scat; A., Secher; J., Semon; D., Simeon; C., Simonin; J. P., Thellier; B., Tourand; A., Vachée; C., Varache; J., Vaucel; A. C., Vautrin; A., Verhaeghe; M., Villemain; L., Villeneuve; Marchandin, Hélène

    2012-01-01

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

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

    USGS Publications Warehouse

    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.

  15. Expression, purification, crystallization and preliminary X-ray analysis of Aeromonas hydrophilia metallo-[beta]-lactamase

    SciTech Connect

    Sharma, N.; Toney, J.H.; Fitzgerald, P.M.D.

    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.

  16. Development of a PCR protocol for the detection of Aeromonas salmonicida in fish by amplification of the fstA (ferric siderophore receptor) gene.

    PubMed

    Beaz-Hidalgo, Roxana; Magi, Gian Enrico; Balboa, Sabela; Barja, Juan L; Romalde, Jesús L

    2008-04-30

    The aims of the study were to evaluate a new PCR protocol designed to detect Aeromonas salmonicida in fish tissues and to develop a non-destructive method for the diagnosis of furunculosis. A set of primers (Fer3, Fer4), flanking a fragment of the fstA gene (coding for the ferric-siderophore receptor) was designed, showing to be sensitive and specific. When compared to PCR methods previously reported, the new protocol recognized all the 69 A. salmonicida strains evaluated, with no cross-reactions with the other bacterial species analysed. Sensitivity assays were performed in fish tissues seeded with serial dilutions of pure cultures of A. salmonicida and mixed cultures of this bacterium with Vibrio anguillarum and Aeromonas hydrophila. Detection limits obtained were of 60 and 450 bacterial cells 100 mg(-1) of tissue, respectively. Mucus and blood were evaluated in order to develop a non-destructive tool to detect the pathogen. The detection limits in seeded mucus and blood samples were 2.5 x 10(2) and 1 x 10(5) bacterial cells mL(-1), respectively. When the method was used to detect A. salmonicida in asymptomatic wild salmon, four samples of mucus and six of blood were positive, corresponding to 6 out of the 31 fish examined, whereas only one of the samples resulted positive by culture methods. It is concluded that the PCR protocol evaluated is fast, specific and sensitive to detect A. salmonicida in infected and asymptomatic fish, and will be helpful for the control of the disease through the prompt detection of carriers within fish populations. PMID:18035507

  17. Antibiogram, Adhesive Characteristics, and Incidence of Class 1 Integron in Aeromonas Species Isolated from Two South African Rivers

    PubMed Central

    Igbinosa, Isoken H.; Chigor, Vincent N.; Igbinosa, Etinosa O.; Obi, Lawrence C.; Okoh, Anthony I.

    2013-01-01

    Aeromonas species are well distributed in freshwater environments, and their natural susceptibility to antimicrobials renders them interesting candidates for the survey of antimicrobial resistance in freshwater milieu. Water samples were collected from Kat and Tyume rivers in the Eastern Cape province of South Africa, and a total of 45 isolates identified as Aeromonas species were recovered from the two rivers. All Aeromonas isolates were resistant to oxacillin, penicillin, clindamycin, cephalothin, vancomycin, and rifamycin, while appreciable susceptibilities (89.3 : 94.1%, 82.1 : 94.1%, 85.7 : 88.2%, and 92.9 : 88.2%) were observed against ciprofloxacin, chloramphenicol, nitrofurantoin, and gentamicin from Kat and Tyume rivers, respectively. Multiple antibiotic resistance (MAR) indices ranged from 0.016 to 0.044 for the two rivers. Class 1 integron was detected in about 20% of the isolates, and all the isolates except one showed ability to produce biofilm in vitro as weak producers (53.33%), moderate producers (15.56%), and strong producers (28.9%). This investigation provides a baseline data on antibiotic resistance as well as the adhesive characteristics of Aeromonas isolates from Tyume and Kat rivers in the Eastern Cape province of South Africa. PMID:24187658

  18. DISTRIBUTION OF SIX VIRULENCE FACTORS IN AEROMONAS SPECIES ISOLATED FROM US DRINKING WATER UTILITIES: A PCR IDENTIFICATION

    EPA Science Inventory

    Surveys of finished drinking water conducted by the U.S. EPA during 2000-2001, revealed 7 out of 16 water utilities encompassing four states, were contaminated with Aeromonas species. A Polymerase Chain reaction (PCR) based genetic characterization determined the presence of six...

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

    PubMed

    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

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

    PubMed

    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

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

    USGS Publications Warehouse

    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.

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

    PubMed Central

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Influence of temperature and process technology on the occurrence of Aeromonas species and hygienic indicator organisms in drinking water production plants.

    PubMed

    Kersters, I; Van Vooren, L; Huys, G; Janssen, P; Kersters, K; Verstraet, W

    1995-09-01

    The occurrence of Aeromonas spp. and hygienic indicator organisms in raw and treated waters of five drinking water production plants in Flanders (Belgium) was surveyed over a period of 17 months. Aeromonads were isolated on ampicillin-dextrin agar (ADA) and further identified by gas-liquid chromatographic analysis of their cellular fatty acid methyl ester (FAME) content. ADA medium was found to be highly specific for the enumeration of Aeromonas spp. In general, Aeromonas counts were very low in untreated groundwater but numbered 10(4)-10(6) colony-forming units per liter in open storage reservoirs for surface water. Aeromonas spp. were seasonally distributed with maximal densities occurring during the summer. The ecology of Aeromonas in the different waters was studied in relation to the physical, chemical, and microbiological water characteristics. Strongly positive correlations were observed between Aeromonas densities and heterotrophic plate counts, whereas a clearly negative relationship was found with dissolved oxygen. On average, 99.7% of the aeromonads were removed by flocculation-decantation followed by breakpoint chlorination, whereas 98.9% were removed by slow sand filtration. Flocculation-decantation without breakpoint chlorination did not reduce the microbial numbers. At three of four drinking water production plants tested, rapid sand filtration decreased the number of aeromonads and hygienic indicator organisms. At one plant, however, the numbers of Aeromonas and hygienic indicator organisms were high in the sand filter effluents. Increased numbers of aeromonads were also counted in the effluent of the activated carbon filters. Hence, inactivation of Aeromonas spp. by the current process technology appears not sufficient to exclude postchlorination. The survival of aeromonads in certain filter systems may be due to the growth of these bacteria on biodegradable organic material, provided by the decomposition from bacteria, algae, or other sources

  5. Aeromonas proteolyrica bacteria in aerospace environments. [possible genetic alterations and effects on man

    NASA Technical Reports Server (NTRS)

    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.

  6. Aeromonas salmonicida subsp. salmonicida in the light of its type-three secretion system

    PubMed Central

    Vanden Bergh, Philippe; Frey, Joachim

    2014-01-01

    Aeromonas salmonicida subsp. salmonicida is an important pathogen in salmonid aquaculture and is responsible for the typical furunculosis. The type-three secretion system (T3SS) is a major virulence system. In this work, we review structure and function of this highly sophisticated nanosyringe in A. salmonicida. Based on the literature as well as personal experimental observations, we document the genetic (re)organization, expression regulation, anatomy, putative functional origin and roles in the infectious process of this T3SS. We propose a model of pathogenesis where A. salmonicida induces a temporary immunosuppression state in fish in order to acquire free access to host tissues. Finally, we highlight putative important therapeutic and vaccine strategies to prevent furunculosis of salmonid fish. PMID:24119189

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

    SciTech Connect

    Castro, Miguel E.; Molina, Roberto C.; Diaz, Waldo A.; Pradenas, Gonzalo A.; Vasquez, Claudio C.

    2009-02-27

    Potassium tellurite (K{sub 2}TeO{sub 3}) 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.

  8. Cylindrospermopsin Biodegradation Abilities of Aeromonas sp. Isolated from Rusałka Lake.

    PubMed

    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. Cylindrospermopsin Biodegradation Abilities of Aeromonas sp. Isolated from Rusałka Lake

    PubMed Central

    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

  10. A Report of Peritonitis from Aeromonas sobria in a Peritoneal Dialysis (PD) Patient with Necrotizing Fasciitis.

    PubMed

    Janma, Jirayut; Linasmita, Patcharasarn; Changsirikulchai, Siribha

    2015-11-01

    A 70-years of age, male patient with underlying type 2 diabetes mellitus, hypertension, dyslipidemia and ischemic heart disease had undergone continuous ambulatory peritoneal dialysis (CAPD)for 3 years without any episodes of peritonitis. He was diagnosed with necrotizing fasciitis and later developed peritonitis after receiving a laceration from an aquatic injury suffered during the flood disaster of 2011. The blood culture, necrotic tissue and the clear dialysate collected upon admission had shown Aeromonas sobria. The route of peritonitis may be from the hematogenous spread of A. sobria resulting in necrotizing fasciitis. A. sobria should be considered as the pathogen of peritonitis in PD patients who have history of wounds from contaminated water. We suggest that the PD patients who present with septicemia and did not meet the criteria for peritonitis, the initial dialysate effluent should be sent for culture. The benefit of this is to allow early recognition and treatment of peritonitis. PMID:27276849

  11. Pathological alterations due to motile Aeromonas infection in red swordtail fish (Xiphophorus helleri).

    PubMed

    Bunnajirakul, S; Pavasutthipaisit, S; Steinhagen, D

    2015-01-01

    A herd of red swordtail fish (Xiphophorus helleri) was reared in outdoor concrete ponds and suffered from occasional mortality. Moribund fishes showing abdominal dropsy and fin rots were sent for diagnosis. Gross necropsy findings showed enlargement of liver, spleen, and kidney in concurrence with congestion, and a severe accumulation of peritoneal fluid. Histopathological findings revealed an alteration of hepatocytes, with a severe diffuse accumulation of fat vacuoles in the cytoplasm. In the trunk kidney, severe accumulation of mononuclear cells together with cloudy swelling of the renal tubular epithelium was observed. From internal organs of the fish motile Aeromonas spp. were identified. The pathological findings might be associated with a long-term infection of affected fish fostered by common stressors such as improper feeding and poor pond environment condition (water temperature). Effective therapeutic measures comprised an advancement of keeping conditions and appropriate feeding to improve the health status in combination with the application of antibiotic substances. PMID:26527040

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

    PubMed

    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

  13. A novel method for the diagnosis of drowning by detection of Aeromonas sobria with PCR method.

    PubMed

    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

  14. Aeromonas salmonicida subsp. salmonicida in the light of its type-three secretion system.

    PubMed

    Vanden Bergh, Philippe; Frey, Joachim

    2014-09-01

    Aeromonas salmonicida subsp. salmonicida is an important pathogen in salmonid aquaculture and is responsible for the typical furunculosis. The type-three secretion system (T3SS) is a major virulence system. In this work, we review structure and function of this highly sophisticated nanosyringe in A. salmonicida. Based on the literature as well as personal experimental observations, we document the genetic (re)organization, expression regulation, anatomy, putative functional origin and roles in the infectious process of this T3SS. We propose a model of pathogenesis where A. salmonicida induces a temporary immunosuppression state in fish in order to acquire free access to host tissues. Finally, we highlight putative important therapeutic and vaccine strategies to prevent furunculosis of salmonid fish. PMID:24119189

  15. The Aeromonas caviae AHA0618 gene modulates cell length and influences swimming and swarming motility

    PubMed Central

    Lowry, Rebecca C; Parker, Jennifer L; Kumbhar, Ramhari; Mesnage, Stephane; Shaw, Jonathan G; Stafford, Graham P

    2015-01-01

    Aeromonas caviae is motile via a polar flagellum in liquid culture, with a lateral flagella system used for swarming on solid surfaces. The polar flagellum also has a role in cellular adherence and biofilm formation. The two subunits of the polar flagellum, FlaA and FlaB, are posttranslationally modified by O-linked glycosylation with pseudaminic acid on 6–8 serine and threonine residues within the central region of these proteins. This modification is essential for the formation of the flagellum. Aeromonas caviae possesses the simplest set of genes required for bacterial glycosylation currently known, with the putative glycosyltransferase, Maf1, being described recently. Here, we investigated the role of the AHA0618 gene, which shares homology (37% at the amino acid level) with the central region of a putative deglycosylation enzyme (HP0518) from the human pathogen Helicobacter pylori, which also glycosylates its flagellin and is proposed to be part of a flagellin deglycosylation pathway. Phenotypic analysis of an AHA0618 A. caviae mutant revealed increased swimming and swarming motility compared to the wild-type strain but without any detectable effects on the glycosylation status of the polar flagellins when analyzed by western blot analysis or mass spectroscopy. Bioinformatic analysis of the protein AHA0618, demonstrated homology to a family of l,d-transpeptidases involved in cell wall biology and peptidoglycan cross-linking (YkuD-like). Scanning electron microscopy (SEM) and fluorescence microscopy analysis of the wild-type and AHA0618-mutant A. caviae strains revealed the mutant to be subtly but significantly shorter than wild-type cells; a phenomenon that could be recovered when either AHA0618 or H. pylori HP0518 were introduced. We can therefore conclude that AHA0618 does not affect A. caviae behavior by altering polar flagellin glycosylation levels but is likely to have a role in peptidoglycan processing at the bacterial cell wall, consequently altering

  16. Acinetobacter, Aeromonas, and Trichococcus populations dominate the microbial community within urban sewer infrastructure

    PubMed Central

    VandeWalle, J. L.; Goetz, G.W.; Huse, S.M.; Morrison, H. G.; Sogin, M.L.; Hoffmann, R.G.; Yan, K.; McLellan, S.L.

    2012-01-01

    We evaluated the population structure and temporal dynamics of the dominant community members within sewage influent from two wastewater treatment plants (WWTPs) in Milwaukee, WI. We generated >1.1M bacterial pyrotag sequences from the V6 hypervariable region of 16S rRNA genes from 38 influent samples and two samples taken upstream in the sanitary sewer system. Only a small fraction of pyrotags from influent samples (~15%) matched sequences from human fecal samples. The fecal components of the sewage samples included enriched pyrotag populations from Lactococcus and Enterobacteriaceae relative to their fractional representation in human fecal samples. In contrast to the large number of distinct pyrotags that represent fecal bacteria such as Lachnospiraceae and Bacteroides, only one or two unique V6 sequences represented Acinetobacter, Trichococcus and Aeromonas, which collectively account for nearly 35% of the total sewage community. Two dominant Acinetobacter V6 pyrotags (designated Acineto tag 1 and Acineto tag 2) fluctuated inversely with a seasonal pattern over a 3-year period, suggesting two distinct Acinetobacter populations respond differently to ecological forcings in the system. A single nucleotide change in the V6 pyrotags accounted for the difference in these populations and corresponded to two phylogenically distinct clades based on full-length sequences. Analysis of wavelet functions, derived from a mathematical model of temporal fluctuations, demonstrated that other abundant sewer associated populations including Trichococcus and Aeromonas had temporal patterns similar to either Acineto tag 1 or Acineto tag 2. Populations with related temporal fluctuations were found to significantly correlate with the same WWTP variables (5-day BOD, flow, ammonia, total phosphorous, and suspended solids). These findings illustrate that small differences in V6 sequences can represent phylogenetically and ecologically distinct taxa. This work provides insight into

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

    USGS Publications Warehouse

    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

  18. Molecular Phylogenetics and Temporal Diversification in the Genus Aeromonas Based on the Sequences of Five Housekeeping Genes

    PubMed Central

    Lorén, J. Gaspar; Farfán, Maribel; Fusté, M. Carmen

    2014-01-01

    Several approaches have been developed to estimate both the relative and absolute rates of speciation and extinction within clades based on molecular phylogenetic reconstructions of evolutionary relationships, according to an underlying model of diversification. However, the macroevolutionary models established for eukaryotes have scarcely been used with prokaryotes. We have investigated the rate and pattern of cladogenesis in the genus Aeromonas (γ-Proteobacteria, Proteobacteria, Bacteria) using the sequences of five housekeeping genes and an uncorrelated relaxed-clock approach. To our knowledge, until now this analysis has never been applied to all the species described in a bacterial genus and thus opens up the possibility of establishing models of speciation from sequence data commonly used in phylogenetic studies of prokaryotes. Our results suggest that the genus Aeromonas began to diverge between 248 and 266 million years ago, exhibiting a constant divergence rate through the Phanerozoic, which could be described as a pure birth process. PMID:24586399

  19. Arsenic binding to iron(II) minerals produced by an iron(III)-reducing Aeromonas strain isolated from paddy soil.

    PubMed

    Wang, Xin-Jun; Chen, Xue-Ping; Kappler, Andreas; Sun, Guo-Xin; Zhu, Yong-Guan

    2009-11-01

    An iron reducing bacterial strain was isolated from a paddy soil and identified as a member of the Aeromonas group by 16S rRNA gene sequence analysis. When the cells were growing with dissolved Fe(III) as electron acceptor in the presence of As(V), Fe(II) minerals (siderite and vivianite) were formed and dissolved As was removed efficiently from solution. When the cells were growing with the Fe(III) hydroxide mineral (ferrihydrite) as electron acceptor in the presence of As(V), ferrihydrite was reduced and dissolved As(V) concentrations decreased sharply. Our results demonstrated firstly that members of the Aeromonas group can reduce Fe(III) in paddy soils, and secondly that iron reduction does not necessarily lead to arsenic mobilization. However, As immobilization can occur in environments that contain significant concentrations of counter ions such as bicarbonate and phosphate. PMID:19572768

  20. Differential partition of virulent Aeromonas salmonicida and attenuated derivatives possessing specific cell surface alterations in polymer aqueous-phase systems

    NASA Technical Reports Server (NTRS)

    Van Alstine, J. M.; Trust, T. J.; Brooks, D. E.

    1986-01-01

    Two-polymer aqueous-phase systems in which partitioning of biological matter between the phases occurs according to surface properties such as hydrophobicity, charge, and lipid composition are used to compare the surface properties of strains of the fish pathogen Aeromonas salmonicida. The differential ability of strains to produce a surface protein array crucial to their virulence, the A layer, and to produce smooth lipopolysaccharide is found to be important in the partitioning behavior of Aeromonas salmonicida. The presence of the A layer is shown to decrease the surface hydrophilicity of the pathogen, and to increase specifically its surface affinity for fatty acid esters of polyethylene glycol. The method has application to the analysis of surface properties crucial to bacterial virulence, and to the selection of strains and mutants with specific surface characteristics.

  1. Virulence and persistence of rough and smooth forms of Aeromonas salmonicida inoculated into coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Anderson, Douglas P.

    1972-01-01

    Virulent isolates of Aeromonas salmonicida showed a majority of smooth colonies, while the attenuated isolates displayed mostly rough colonies. A lesion occurred at the site of inoculation when one of the rough forms was inoculated into yearling coho salmon, but few mortalities were recorded even though the rough forms were readily recovered from both the lesion and the kidney. The fish inoculated with the same dosage of smooth forms all died within 96 hr of inoculation.

  2. Identification of antibiotic resistance cassettes in class 1 integrons in Aeromonas spp. strains isolated from fresh fish (Cyprinus carpio L.).

    PubMed

    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

  3. Use of Aeromonas spp. as General Indicators of Antimicrobial Susceptibility among Bacteria in Aquatic Environments in Thailand.

    PubMed

    Usui, Masaru; Tagaki, Chie; Fukuda, Akira; Okubo, Torahiko; Boonla, Chanchai; Suzuki, Satoru; Seki, Kanako; Takada, Hideshige; Tamura, Yutaka

    2016-01-01

    Antimicrobials are widely used, not only for treating human infections, but also for treatment of livestock and in fish farms. Human habitats in Southeastern Asian countries are located in close proximity to aquatic environments. As such, the human populations within these regions are at risk of exposure to antimicrobial resistant bacteria, and thereby disseminating antimicrobial resistance genes (ARGs). In this study, we collected water samples from 15 sites (5 sites in Chao Phraya River, 2 sites at the mouth of Chao Phraya River, 3 sites in Ta Chin River, and 5 sites at city canals) and 12 sites (6 sites at city canals; 2 sites at chicken farms; 2 sites at pig farms; and 2 samples from sites at pig farms, which were subsequently treated at a biogas plant) in Thailand in 2013 and 2014, respectively. In total, 117 Aeromonas spp. were isolated from the water samples, and these organisms exhibited various antimicrobial susceptibility profiles. Notably, there was a significant correlation between the environmental concentration of tetracyclines and the rates of tetracycline resistance in the isolated Aeromonas spp.; however, both the concentration and rates of tetracycline resistance in samples derived from pig farms were higher than those of samples harvested from other aquatic environments. These findings suggest that the high concentrations of antimicrobials observed in these aquatic environments likely select for ARGs. Furthermore, they indicate that Aeromonas spp. comprise an effective marker for monitoring antimicrobial resistance in aquatic environments. PMID:27433156

  4. Use of Aeromonas spp. as General Indicators of Antimicrobial Susceptibility among Bacteria in Aquatic Environments in Thailand

    PubMed Central

    Usui, Masaru; Tagaki, Chie; Fukuda, Akira; Okubo, Torahiko; Boonla, Chanchai; Suzuki, Satoru; Seki, Kanako; Takada, Hideshige; Tamura, Yutaka

    2016-01-01

    Antimicrobials are widely used, not only for treating human infections, but also for treatment of livestock and in fish farms. Human habitats in Southeastern Asian countries are located in close proximity to aquatic environments. As such, the human populations within these regions are at risk of exposure to antimicrobial resistant bacteria, and thereby disseminating antimicrobial resistance genes (ARGs). In this study, we collected water samples from 15 sites (5 sites in Chao Phraya River, 2 sites at the mouth of Chao Phraya River, 3 sites in Ta Chin River, and 5 sites at city canals) and 12 sites (6 sites at city canals; 2 sites at chicken farms; 2 sites at pig farms; and 2 samples from sites at pig farms, which were subsequently treated at a biogas plant) in Thailand in 2013 and 2014, respectively. In total, 117 Aeromonas spp. were isolated from the water samples, and these organisms exhibited various antimicrobial susceptibility profiles. Notably, there was a significant correlation between the environmental concentration of tetracyclines and the rates of tetracycline resistance in the isolated Aeromonas spp.; however, both the concentration and rates of tetracycline resistance in samples derived from pig farms were higher than those of samples harvested from other aquatic environments. These findings suggest that the high concentrations of antimicrobials observed in these aquatic environments likely select for ARGs. Furthermore, they indicate that Aeromonas spp. comprise an effective marker for monitoring antimicrobial resistance in aquatic environments. PMID:27433156

  5. First record of the rare species Aeromonas schubertii from mussels: phenotypic and genetic reevaluation of the species and a review of the literature.

    PubMed

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

    2016-05-01

    In a study where the prevalence of Aeromonas in shellfish was analysed, three isolates of Aeromonas schubertii were identified, representing this the first report of this species from mussels. This species was originally described in 1988 from strains isolated from extra-intestinal human infections and since then has been cited in only 18 occasions. For many years, A. schubertii was the only mannitol-negative species of the genus. However, three additional mannitol-negative species (Aeromonas simiae, Aeromonas diversa and Aeromonas australiensis) have been described. This, together with the fact that A. schubertii is a rare human pathogenic species, motivated the present study to characterize its biochemical behaviour and differentiation from the other mannitol-negative species. The molecular similarity (16S rRNA, rpoD and gyrB genes) of the strains, presence of virulence genes and antimicrobial resistance were determined. All A. schubertii strains showed the same phenotypic behaviour, i.e. they use citrate, are positive for lysine decarboxylase and DL-lactate, but negative for production of mannitol, indole and acid from sucrose and could be easily differentiated from other mannitol-negative species. All strains carried the aerA and lafA virulence genes and showed susceptibility to all antibiotics tested. Seafood could be a transmission route of this bacterium to humans. PMID:26825089

  6. Adhesion, invasion, intracellular survival and cytotoxic activity of strains of Aeromonas spp. in HEp-2, Caco-2 and T-84 cell lines.

    PubMed

    dos Santos, Paula Azevedo; Pereira, Ana Claudia Machado; Ferreira, Andréa Fonseca; de Mattos Alves, Maria Angélica; Rosa, Ana Cláudia Paula; Freitas-Almeida, Angela Corrêa

    2015-05-01

    The genus Aeromonas contains important pathogen for both humans and other animals, being responsible for the etiology of intestinal and extraintestinal diseases. The pathology caused by these bacteria involves several virulence factors, such as the ability to produce toxins, adhesion and invasion. The properties conferred by these factors have been extensively studied in experiments of interaction between bacterial strains and cell culture. We evaluate the interaction of eight Aeromonas spp. strains, previously isolated from human faeces, food and water with HEp-2, Caco-2 and T-84 cell lines. Cytotoxic effects, the pattern of adhesion, invasive capacity and intracellular survival were analyzed. The results showed that Aeromonas strains were adherent to three cells lines in 6 h of incubation, displaying the aggregative adherence pattern. Among eight strains studied, 50% produced cytotoxic effects on HEp-2 cells, while none of the strains produced cytotoxic effects on Caco-2 and T-84 cells at 48 h. This study demonstrated that subsets of Aeromonas isolated from different sources were able to invade intestinal (T-84, Caco-2) and epithelial (HEp-2) cell lines cultivated in vitro surviving in intracellular environments up to 72 h. Finally, our results support the pathogenic potential of Aeromonas, especially those of food and clinical sources. PMID:25743539

  7. The dihydrolipoamide dehydrogenase of Aeromonas caviae ST exhibits NADH-dependent tellurite reductase activity.

    PubMed

    Castro, Miguel E; Molina, Roberto; Díaz, Waldo; Pichuantes, Sergio E; Vásquez, Claudio C

    2008-10-10

    Potassium tellurite (K(2)TeO(3)) is extremely toxic for most forms of life and only a limited number of organisms are naturally resistant to the toxic effects of this compound. Crude extracts prepared from the environmental isolate Aeromonas caviae ST catalize the in vitro reduction of TeO32- in a NADH-dependent reaction. Upon fractionation by ionic exchange column chromatography three major polypeptides identified as the E1, E2, and E3 components of the pyruvate dehydrogenase (PDH) complex were identified in fractions exhibiting tellurite-reducing activity. Tellurite reductase and pyruvate dehydrogenase activities co-eluted from a Sephadex gel filtration column. To determine which component(s) of the PDH complex has tellurite reductase activity, the A. caviae ST structural genes encoding for E1 (aceE), E2 (aceF), and E3 (lpdA) were independently cloned and expressed in Escherichia coli and their gene products purified. Results indicated that tellurite reductase activity lies almost exclusively in the E3 component, dihydrolipoamide dehydrogenase. The E3 component of the PDH complex from E. coli, Zymomonas mobilis, Streptococcus pneumoniae, and Geobacillus stearothermophilus also showed NADH-dependent tellurite reductase in vitro suggesting that this enzymatic activity is widely distributed among microorganisms. PMID:18675788

  8. Aeromonas salmonicida Ati2 is an effector protein of the type three secretion system.

    PubMed

    Dallaire-Dufresne, Stéphanie; Barbeau, Xavier; Sarty, Darren; Tanaka, Katherine H; Denoncourt, Alix M; Lagüe, Patrick; Reith, Michael E; Charette, Steve J

    2013-09-01

    The bacterium Aeromonas salmonicida, a fish pathogen, uses the type three secretion system (TTSS) to inject effector proteins into host cells to promote the infection. The study of the genome of A. salmonicida has revealed the existence of Ati2, a potential TTSS effector protein. In the present study, a structure-function analysis of Ati2 has been done to determine its role in the virulence of A. salmonicida. Biochemical assays revealed that Ati2 is secreted into the medium in a TTSS-dependent manner. Protein sequence analyses, molecular modelling and biochemical assays demonstrated that Ati2 is an inositol polyphosphate 5-phosphatase, which hydrolyses PtdIns(4,5)P2 and PtdIns(3,4,5)P3 in a way similar to VPA0450, a protein from Vibrio parahaemolyticus having high sequence similarity with Ati2. Mutants of Ati2 with altered amino acids at two different locations in the catalytic site displayed no phosphatase activity. Wild-type and mutant forms of Ati2 were cloned into expression systems for Dictyostelium discoideum, a soil amoeba used as an alternative host to study A. salmonicida virulence. Expression tests allowed us to demonstrate that Ati2 is toxic for the host cell in a catalytic-dependent manner. Finally, this study demonstrated the existence of a new TTSS effector protein in A. salmonicida. PMID:23832001

  9. Evidence for the subcellular localization and specificity of chlordane inhibition in the marine bacterium Aeromonas proteolytica.

    PubMed Central

    Nakas, J P; Litchfield, C D

    1979-01-01

    Sublethal levels (10 to 100 micrograms/ml) of the chlorinated insecticide chlordane (1,2,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-methanoindan) were introduced into the growth medium of the marine bacterium, Aeromonas proteolytica. Chlordane inhibited the synthesis of an extracellular endopeptidase by almost 40% but exhibited no such inhibition of the extracellular aminopeptidase also produced during the growth cycle. Studied with 14C-labeled chlordane demonstrated that the insecticide was not biologically degraded under the test conditions used and that up to 75% of the recoverable chlordane was cell associated within 48 h. Studied with uniformly labeled L[14C]valine and [2-14C]uracil established that neither the transport nor the incorporation of these protein and ribonucleic acid precursors was inhibited by chlordane. Separation of the membrane fractions using isopycnic centrifugation localized 14C-labeled chlordane in the cytoplasmic membrane. Also, chlordane inhibited the membrane-bound adenosine 5'-triphosphatase while the soluble (released) form of this enzyme remained unaffected. These data indicate that chlordane resides in the cytoplasmic membrane and may cause specific alterations in membrane-associated activities. PMID:156517

  10. Novel application of Mahua (Madhuca sp.) flowers for augmented protease production from Aeromonas sp. S1.

    PubMed

    Bhattacharya, Amrik; Saini, Vandana; Gupta, Anshu

    2012-10-01

    The present study explored the utilization of Mahua (Madhuca sp.) flowers, a major non-timber forest product (NTFP) of India, as a low-cost, natural substrate for protease production under submerged fermentation. Bacterial strain Aeromonas sp. Si1, previously reported by us, was used as the protease producer. Using Mahua flower extract (MFE) as the medium additive, the protease production could successfully be enhanced by 5.6-fold (564.5 UmL-1) after 24 h of fermentation under optimized conditions compared with initial production of 99.9 UmL' in the absence of MFE. The cultural parameters for optimum production of protease were determined to be: incubation time-24 h; pH-7.0; MFE concentration-5% (v/v); inoculum size-0.3% (v/v) and agitation rate-200 rpm. The results obtained demonstrate the potential of cheaper and abundantly available Mahua flowers for induction of proteases, and thus offer a new approach for value addition to this biomass through industrial enzyme production. PMID:23157010

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

    PubMed

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

    2015-04-01

    Peracetic acid (PAA) is a therapeutic agent used for disinfection in aquaculture, but it must be investigated thoroughly in order to mitigate diseases without harming the fish. Successful disinfectants (like PAA) should not leave dangerous residues in the environment in order to successfully contribute to sustainable aquaculture. The aim of our study was to compare the effectiveness of 6 commercial PAA products with different molecular PAA:H2O2 ratios to reduce bacterial growth of Aeromonas salmonicida and Yersinia ruckeri and to determine effective concentrations and exposure times. All products reduced colony-forming units (CFUs) of A. salmonicida and Y. ruckeri. Products with higher molecular PAA:H2O2 ratios inhibited growth better than products with lower molecular PAA:H2O2 ratios at the same PAA concentration; this indicates that H2O2 is not the driving force in the reduction of A. salmonicida and Y. ruckeri growth by PAA in vitro. The practical application of the products with high molecular PAA:H2O2 ratios should be prioritized if these pathogens are diagnosed. PMID:25850398

  12. Active intermediates of polyhydroxyalkanoate synthase from Aeromonas caviae in polymerization reaction.

    PubMed

    Numata, Keiji; Motoda, Yoko; Watanabe, Satoru; Tochio, Naoya; Kigawa, Takanori; Doi, Yoshiharu

    2012-11-12

    Polyhydroxyalkanoate (PHA) synthase from Aeromonas caviae FA440 (PhaC(Ac), BAA21815) is one of the most valuable PHA synthase, because of its function to synthesize a practical bioplastic, poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] [P(3HB-co-3HHx)]. However, biochemical activity and active intermediates of PhaC(Ac) have not been clarified until now. In the present study, a gene of PhaC(Ac) was cloned and overexpressed by a cell-free protein expression system. Both the polymerization activity and oligomerization behavior of the purified PhaC(Ac) were characterized in order to clarify the active intermediates of PhaC(Ac) based on the hydrodynamic diameters and specific activities of PhaC(Ac). The influences of a substrate, (R)-3-hydroxybutyryl-CoA (3HB-CoA), on the oligomerization of PhaC(Ac) (7.5 μM) were also investigated, and then the Hill coefficient (n = 2.6 ± 0.4) and the microscopic dissociation constant (K(m) = 77 ± 5 μM) were determined. Based on the results, the active intermediate of PhaC(Ac) was concluded to be the dimeric PhaC(Ac) containing 3HB-CoA as an activator for its dimerization. This information is critical for revealing the relationships between its dimerization and function in PHA synthesis. PMID:23043466

  13. Aeromonas sobria infection in farmed mud loach (Misgurnus mizolepis) in Korea, a bacteriological survey

    PubMed Central

    Yu, J; Koo, B. H; Kim, D. H; Kim, D. W; Park, S. W

    2015-01-01

    A disease outbreak occurred in June 2012 among mud loach cultured on pond farms in Jangseong-gun, Jeollanam-do, Korea. Mortality rates reached up to 1.2% in the farm per day. Typical clinical signs were bleeding ulcer at the middle portion of head and haemorrhagic erosion of the operculum. Based on biochemical characteristics, the causative bacterium isolated from diseased fish was identified as Aeromonas sobria. The isolate expressed two haemolytic genes, aerolysin (sob) and haemolysin (asa1) genes. Histopathologically, liver showed hepatocellular vacuolar degeneration and congestion in sinusoids. The spleen exhibited necrotized splenocytes and haemorrhagic pulps. In the kidney, glomerular destruction, renal tubular necrosis and haemorrhage were observed. Experimental infection (infectious dose of 106, 107, and 108 cfu fish-1) of healthy mud loach with the isolate resulted in the development of clinical signs similar to those seen in the farm. By injection with an infectious dose of 106 cfu fish-1, the mortality rate was 10.3% within 7 days post infection. A mortality rate of 60.9% was reached within 2 days when an infectious dose of 107 cfu fish-1 was used. Otherwise, all fish died within 1 day when injected with 108 cfu fish-1. The results demonstrated that A. sobria is involved in the morbidity and mortality of the farmed mud loach. PMID:27175175

  14. On the mechanism underlying tellurite reduction by Aeromonas caviae ST dihydrolipoamide dehydrogenase.

    PubMed

    Arenas, F A; Leal, C A; Pinto, C A; Arenas-Salinas, M A; Morales, W A; Cornejo, F A; Díaz-Vásquez, W A; Vásquez, C C

    2014-07-01

    The dihydrolipoamide dehydrogenase (LpdA) from the tellurite-resistant bacterium Aeromonas caviae ST reduces tellurite to elemental tellurium. To characterize this NADH-dependent activity, the A. caviae lpdA gene was subjected to site-directed mutagenesis and genes containing C45A, H322Y and E354K substitutions were individually transformed into Escherichia coli Δlpd. Cells expressing the modified genes exhibited decreased pyruvate dehydrogenase, dihydrolipoamide dehydrogenase and TR activity regarding that observed with the wild type A. caviae lpdA gene. In addition, cells expressing the altered lpdA genes showed increased oxidative stress levels and tellurite sensitivity than those carrying the wild type counterpart. The involvement of Cys residues in LpdA's TR activity was analyzed using specific inhibitors that interact with catalytic cysteines and/or disulfide bridges such as aurothiomalate, zinc or nickel. TR activity of purified LpdA was drastically affected by these compounds. Since LpdA belongs to the flavoprotein family, the involvement of the FAD/NAD(P)(+)-binding domain in TR activity was determined. FAD removal from purified LpdA results in loss of TR activity, which was restored with exogenously added FAD. Substitutions in E354, involved in FAD/NADH binding, resulted in low TR activity because of flavin loss. Finally, changing H322 (involved in NAD(+)/NADH binding) by tyrosine also resulted in altered TR activity. PMID:24680738

  15. Effect of a phytogenic feed additive on the susceptibility of Onchorhynchus mykiss to Aeromonas salmonicida.

    PubMed

    Menanteau-Ledouble, S; Krauss, I; Santos, G; Fibi, S; Weber, B; El-Matbouli, M

    2015-06-29

    In recent years, feed additives have increasingly been adopted by the aquaculture industry. These supplements not only offer an alternative to antibiotics but have also been linked to enhanced growth performance. However, the literature is still limited and provides contradictory information on their effectiveness. This is mainly due to the wide variety of available products and their complex mechanisms of action. Phytogenic feed additives have been shown to have antimicrobial effects and can improve growth performance. In the present study, we investigated the susceptibility of several fish pathogenic bacteria to a phytogenic essential oil product in vitro. In addition, we determined the protective effect of a commercial phytogenic feed additive containing oregano, anis and citrus oils on the resistance of rainbow trout Oncorhynchus mykiss to infection by Aeromonas salmonicida. The bacterium was administered through 3 different routes: intra-peritoneal injection, immersion in a bacterial solution and cohabitation with infected fish. Mortality rates were significantly lower in infected rainbow trout that had received the feed additive: the overall mortality rate across all routes of infection was 18% in fish fed a diet containing the additive compared to 37% in fish that received unsupplemented feed. The route of infection also significantly impacted mortality, with average mortality rates of 60, 17.5 and 5% for intra-peritoneal injection, immersion and cohabitation, respectively. In general, fish were better protected against infection by immersion than infection by injection. PMID:26119300

  16. Insertion sequence AS5 (ISAS5) is involved in the genomic plasticity of Aeromonas salmonicida

    PubMed Central

    Trudel, Mélanie V.; Tanaka, Katherine H.; Filion, Geneviève; Daher, Rana K.; Frenette, Michel; Charette, Steve J.

    2013-01-01

    The genome of the fish pathogen Aeromonas salmonicida subsp salmonicida harbors a large number of insertion sequences (ISs), many of which are located on plasmids. In the present study, we analyzed the small plasmid profile of A. salmonicida strains to identify evidences of plasmid alterations. Ten out of 78 strains analyzed displayed an unconventional plasmid profile. However the HER1104 strain was unique, having a positive PCR signal for pAsal1 plasmid despite not carrying this plasmid. Instead, HER1104 was bearing a plasmid at higher molecular weight than pAsal1. We characterized this new larger plasmid, which we called pAsal1B since it is a derivative of pAsal1 containing one more complete IS (ISAS5) than the parental plasmid. An additional 96 bp relic of ISAS5 was also present in pAsal1B. These results propose that ISAS5 is another active mobile genetic element in A. salmonicida subsp salmonicida and provided further proof of the genomic plasticity of this bacterium. PMID:23956951

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

    PubMed

    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

  18. Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea

    PubMed Central

    Kim, Ji Hyung; Hwang, Sun Young; Son, Jee Soo; Han, Jee Eun; Jun, Jin Woo; Shin, Sang Phil; Choresca, Casiano; Choi, Yun Jaie; Park, Yong Ho

    2011-01-01

    The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser83→Arg83 or Ser83→Asn83. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida. PMID:21368562

  19. Development and validation of a real-time PCR assay for the detection of Aeromonas salmonicida.

    PubMed

    Keeling, S E; Brosnahan, C L; Johnston, C; Wallis, R; Gudkovs, N; McDonald, W L

    2013-05-01

    A real-time PCR assay using a molecular beacon was developed and validated to detect the vapA (surface array protein) gene in the fish pathogen, Aeromonas salmonicida. The assay had 100% analytical specificity and analytical sensitivities of 5 ± 0 fg (DNA), 2.2 × 10(4) ± 1 × 10(4) CFU g(-1) (without enrichment) and 40 ± 10 CFU g(-1) (with enrichment) in kidney tissue. The assay was highly repeatable and proved to be robust following equivalency testing using a different real-time PCR platform. Following analytical validation, diagnostic specificity was determined using New Zealand farmed Chinook salmon, Oncorhynchus tshawytscha (Walbaum), (n = 750) and pink shubunkin, Carassius auratus (L.) (n = 157). The real-time PCR was run in parallel with culture and all fish tested were found to be negative by both methods for A. salmonicida, resulting in 100% diagnostic specificity (95% confidence interval). The molecular beacon real-time PCR system is specific, sensitive and a reproducible method for the detection of A. salmonicida. It can be used for diagnostic testing, health certification and active surveillance programmes. PMID:23121198

  20. Detection of Aeromonas salmonicida by reverse transcription-multiplex polymerase chain reaction.

    PubMed

    Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat

    2012-01-01

    Aeromonas salmonicida is one of the major fish pathogens causing economically devastating losses in aquaculture. A. salmonicida subsp. salmonicida is a typical A. salmonicida causing furunculosis, while the other subspecies are atypical strains causing ulcer diseases. PCR-based methods of detecting A. salmonicida suffer from the drawback that they do not distinguish living (pathogenic) from dead cells. In this study, a method of detecting A. salmonicida was developed based on reverse transcription-multiplex PCR (RT-MPCR) using two sets of primers, SV1/SV2 and SF1/SF2, specific to the vapA gene and the fstB gene of A. salmonicida respectively. This method was found to detect A. salmonicida specifically with detection limits of 10 CFU in pure culture and 30 CFU in the presence of tissue debris. It was also found distinguish not only between viable and nonviable cells but also between typical and atypical strains of A. salmonicida. Using RT-MPCR, two DNA fragments, of 542 and 1,258 bp, were amplified from RNA of typical A. salmonicida, whereas only one DNA fragment, of 542 bp, was amplified from the RNA of the atypical ones. The proposed assay was also used successfully to detect A. salmonicida in artificially infected rainbow trout (Oncorhyncus mykiss). PMID:22484927

  1. Variants of a genomic island in Aeromonas salmonicida subsp. salmonicida link isolates with their geographical origins.

    PubMed

    Emond-Rheault, Jean-Guillaume; Vincent, Antony T; Trudel, Mélanie V; Brochu, Francis; Boyle, Brian; Tanaka, Katherine H; Attéré, Sabrina A; Jubinville, Éric; Loch, Thomas P; Winters, Andrew D; Faisal, Mohamed; Frenette, Michel; Derome, Nicolas; Charette, Steve J

    2015-01-30

    Aeromonas salmonicida subsp. salmonicida is a fish pathogen. Analysis of its genomic characteristics is required to determine the worldwide distribution of the various populations of this bacterium. Genomic alignments between the 01-B526 pathogenic strain and the A449 reference strain have revealed a 51-kb chromosomal insertion in 01-B526. This insertion (AsaGEI1a) has been identified as a new genomic island (GEI) bearing prophage genes. PCR assays were used to detect this GEI in a collection of 139 A. salmonicida subsp. salmonicida isolates. Three forms of this GEI (AsaGEI1a, AsaGEI1b, AsaGEI2a) are now known based on this analysis and the sequencing of the genomes of seven additional isolates. A new prophage (prophage 3) associated with AsaGEI2a was also discovered. Each GEI appeared to be strongly associated with a specific geographic region. AsaGEI1a and AsaGEI2a were exclusively found in North American isolates, except for one European isolate bearing AsaGEI2a. The majority of the isolates bearing AsaGEI1b or no GEI were from Europe. Prophage 3 has also a particular geographic distribution and was found only in North American isolates. We demonstrated that A. salmonicida subsp. salmonicida possesses unsuspected elements of genomic heterogeneity that could be used as indicators to determine the geographic origins of isolates of this bacterium. PMID:25480167

  2. Aeromonas jandaei (formerly genospecies DNA group 9 A. sobria), a new sucrose-negative species isolated from clinical specimens.

    PubMed Central

    Carnahan, A; Fanning, G R; Joseph, S W

    1991-01-01

    A large numerical taxonomy study conducted in 1988 of 165 mostly clinical Aeromonas strains from diverse geographic sources produced a cluster (S = 84%, SSM) of four sucrose-negative strains that included the DNA definition strain for DNA group 9 A. sobria (CDC 0787-80). These four strains, together with five additional strains received in 1989, were subjected to DNA-DNA hybridization (hydroxyapatite, 32P, 60 and 75 degrees C), and all eight strains were closely related to the ninth labeled DNA group 9 definition strain CDC 0787-80 (73 to 86% relatedness at 60 degrees C and 68 to 80% relatedness at 75 degrees C; percent divergence, 2.0 to 3.5). Type strains and DNA definition strains for all other established Aeromonas species were only 35 to 72% related (60 degrees C) to CDC 0787-80. We propose the name Aeromonas jandaei for this highly related group of nine strains, formerly known as DNA group 9 A. sobria. The type strain was designated ATCC 49568 (CDC 0787-80). The nine strains were examined at 36 degrees C and were found to be resistant to 0/129 (vibriostatic agent) and uniformly positive for oxidase, gas production from glucose, indole, lysine decarboxylase, arginine dihydrolase, o-nitrophenyl-beta-D-galactopyranoside, motility (25 degrees C), nitrate reduction, citrate utilization, hemolysis on sheep blood agar, and growth in Trypticase soy broth with no added NaCl. They all fermented D-glucose, D-mannitol, and mannose but did not ferment sucrose, cellobiose, L-arabinose, inositol, salicin, or D-sorbitol. They were uniformly negative for esculin and urea hydrolysis, elastase production, ornithine decarboxylation, and the string test. The antibiogram of A. jandaei resembled that of other aeromonads (resistance to ampicillin and cephalothin), but it differed from most other aeromonads because of resistance to single dilution of colistin and differed from clinical A. veronii biogroup sorbria (formerly A. sobria) by its nearly uniform resistance to cephalothin

  3. Inhibition of biosynthesis of metalloprotease of Aeromonas sobria by sodium chloride in the medium.

    PubMed

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

    2011-01-01

    The present authors have previously shown that the serine protease activity of Aeromonas sobria is markedly decreased when A. sobria is cultured in medium containing 3.0% sodium chloride (NaCl, concentration almost equivalent to sea water salinity), and that this occurs because, although the synthesis of ASP is not disturbed by the salt in the medium, the maturation pathway of serine protease of A. sobria (ASP) does not proceed successfully in such a medium. In this study, the effect of salt in the medium on the production of metalloprotease by A. sobria (AMP) was examined. A. sobria produced AMP in the milieu when the bacteria were cultured in medium containing (NaCl) at a concentration of 0.5%. However, AMP was not produced when the bacteria were cultured in salty medium containing 1.5% or more NaCl. To examine how NaCl reduces the production of metalloprotease by A. sobria, the amount of amp mRNA in the cell was measured and it was found that this decreased in proportion to the concentration of NaCl in the medium. The mRNA of amp was not detected in cells cultured in medium containing 1.5% or more NaCl. This means that the transcription of amp is inhibited in salty condition. As described, NaCl in the medium disturbs the maturation pathway of ASP. The mode of action whereby NaCl suppresses AMP activity in A. sobria differs from the mechanism for suppressing ASP activity. PMID:21175775

  4. Evaluation of commercially prepared transport systems for nonlethal detection of Aeromonas salmonicida in salmonid fish

    USGS Publications Warehouse

    Cipriano, R.C.; Bullock, G.L.

    2001-01-01

    In vitro studies indicated that commercially prepared transport systems containing Amies, Stuart's, and Cary-Blair media worked equally well in sustaining the viability of the fish pathogen Aeromonas salmonicida, which causes furunculosis. The bacterium remained viable without significant increase or decrease in cell numbers for as long as 48 h of incubation at 18-20??C in Stuart's transport medium; consequently, obtaining mucus samples in such tubes were comparable to on-site detection of A. salmonicida by dilution plate counts on Coomassie Brilliant Blue agar. In three different assays of 100 samples of mucus from Atlantic salmon Salmo salar infected subclinically with A. salmonicida, dilution counts conducted on-site proved more reliable for detecting the pathogen than obtaining the samples in the transport system. In the on-site assays, dilution counts detected the pathogen in 34, 41, and 22 samples, whereas this was accomplished in only 15, 15, and 3 of the respective samples when the transport system was used. In an additional experiment, Arctic char Salvelinus alpinus sustaining a frank epizootic of furunculosis were sampled similarly. Here, too, dilution counts were more predictive of the prevalence of A. salmonicida and detected the pathogen in 46 mucus samples; in comparison, only 6 samples collected by using the transport system were positive. We also observed that the transport system supported the growth of the normal mucus bacterial flora. Particularly predominant among these were motile aeromonads and Pseudomonas fluorescens. In studies of mixed culture growth, two representatives of both of the latter genera of bacteria outgrew A. salmonicida - in some cases, to the total exclusion of the pathogen itself.

  5. A Chitinase from Aeromonas veronii CD3 with the Potential to Control Myxozoan Disease

    PubMed Central

    Liu, Yuchun; Zhou, Zhigang; Miao, Wei; Zhang, Yuting; Cao, Yanan; He, Suxu; Bai, Dongqing; Yao, Bin

    2011-01-01

    Background The class Myxosporea encompasses about 2,400 species, most of which are parasites of fish and cause serious damage in aquaculture. Due to the concerns about food safety issues and limited knowledge of Myxozoa life cycle and fish immune system, no chemicals, antibiotics or immune modulators are available to control myxozoa infection. Therefore, little can be done once Myxozoa establishment has occurred. Methodology/Principal Findings In this paper we isolated Aeromonas veronii CD3 with significant myxospore shell valve-degrading ability from pond sediment. A 3,057-bp full-length chitinase gene was consequently cloned, and the corresponding mature, recombinant chitinase (ChiCD3) produced by Escherichia coli had substantial chitinase activity. The deduced sequence of ChiCD3 contained one catalytic domain, two chitin-binding domains, and one putative signal peptide. ChiCD3 had an optimal activity at 50°C and pH 6.0, and retained more than 50% of its optimal activity under warm water aquaculture conditions (∼30°C and pH ∼7.0). After incubation with ChiCD3, 38.0±4.8% of the myxospores had damaged shell valves, whereas myxospores incubated with commercially available chitinases remained intact. Conclusion/Significance This study reveals a new strategy to control myxozoan disease. ChiCD3 that has capacity to damage the shell valve of myxospores can be supplemented into fish feed and used to control Myxozoa-induced diseases specifically. PMID:22205999

  6. Antibiotic resistance due to an unusual ColE1-type replicon plasmid in Aeromonas salmonicida.

    PubMed

    Vincent, Antony T; Emond-Rheault, Jean-Guillaume; Barbeau, Xavier; Attéré, Sabrina A; Frenette, Michel; Lagüe, Patrick; Charette, Steve J

    2016-06-01

    Aeromonas salmonicida subsp. salmonicida is a fish pathogen known to have a rich plasmidome. In the present study, we discovered an isolate of this bacterium bearing an additional unidentified small plasmid. After having sequenced the DNA of that isolate by next-generation sequencing, it appeared that the new small plasmid is a ColE1-type replicon plasmid, named here pAsa7. This plasmid bears a functional chloramphenicol-acetyltransferase-encoding gene (cat-pAsa7) previously unknown in A. salmonicida and responsible for resistance to chloramphenicol. A comparison of pAsa7 with pAsa2, the only known ColE1-type replicon plasmid usually found in A. salmonicida subsp. salmonicida, revealed that even if both plasmids share a high structural similarity, it is still unclear if pAsa7 is a derivative of pAsa2 since they showed several mutations at the nucleotide level. Transcriptomic analysis revealed that the cat-pAsa4 gene, another chloramphenicol-acetyltransferase-encoding gene, found on the large plasmid pAsa4, was significantly more transcribed than cat-pAsa7. This was correlated with a higher chloramphenicol resistance for isolates bearing pAsa4 compared with the one having pAsa7. Finally, a phylogenetic analysis showed that both CAT-pAsa4 and CAT-pAsa7 proteins were in different clusters. The clustering was supported by the identity of residues involved in the catalytic site. In addition, to give a better understanding of the large drug-resistance panel of A. salmonicida, this study reinforces the hypothesis that A. salmonicida subsp. salmonicida is a considerable reservoir for mobile genetic elements such as plasmids. PMID:27028891

  7. Phasin proteins activate Aeromonas caviae polyhydroxyalkanoate (PHA) synthase but not Ralstonia eutropha PHA synthase.

    PubMed

    Ushimaru, Kazunori; Motoda, Yoko; Numata, Keiji; Tsuge, Takeharu

    2014-05-01

    In this study, we performed in vitro and in vivo activity assays of polyhydroxyalkanoate (PHA) synthases (PhaCs) in the presence of phasin proteins (PhaPs), which revealed that PhaPs are activators of PhaC derived from Aeromonas caviae (PhaCAc). In in vitro assays, among the three PhaCs tested, PhaCAc was significantly activated when PhaPs were added at the beginning of polymerization (prepolymerization PhaCAc), whereas the prepolymerization PhaCRe (derived from Ralstonia eutropha) and PhaCDa (Delftia acidovorans) showed reduced activity with PhaPs. The PhaP-activated PhaCAc showed a slight shift of substrate preference toward 3-hydroxyhexanoyl-CoA (C6). PhaPAc also activated PhaCAc when it was added during polymerization (polymer-elongating PhaCAc), while this effect was not observed for PhaCRe. In an in vivo assay using Escherichia coli TOP10 as the host strain, the effect of PhaPAc expression on PHA synthesis by PhaCAc or PhaCRe was examined. As PhaPAc expression increased, PHA production was increased by up to 2.3-fold in the PhaCAc-expressing strain, whereas it was slightly increased in the PhaCRe-expressing strain. Taken together, this study provides evidence that PhaPs function as activators for PhaCAc both in vitro and in vivo but do not activate PhaCRe. This activating effect may be attributed to the new role of PhaPs in the polymerization reaction by PhaCAc. PMID:24584238

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

    PubMed

    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. CHARACTERIZATION OF PRECURSOR FOR 16S rRNA FOR AEROMONAS HYDROPHILA

    EPA Science Inventory

    Current strategies for monitoring drinking water quality involve culture-based methods to detect the presence of microbial indicators. However, these methods are insensitive when the organisms have undergone physiological changes such as injury and starvation that can occur in h...

  10. Immune responses to Aeromonas hydrophila in catfish (Heteropneustis fossilis) exposed to cadmium and hexachlorocyclohexane

    SciTech Connect

    Saxena, M.P.; Gopal, K.; Jones, W.; Ray, P.K. )

    1992-02-01

    Fishes are poikilothermic vertebrates hence all the body functions including immunological defense may be susceptible to adverse changes in the aquatic environment. Environmental pollutants, especially heavy metals and pesticides are known to contribute to outbreaks of infectious bacterial diseases in fishes. Pesticides enter the aquatic environment through intentional application, aerial drift or runoff from applications or accidental release and then become rapidly distributed. Major routes of pesticide movement into water are agricultural runoff from fields and grazing lands. Several investigators have evaluated the toxicity of hexachlorocyclohexane (HCH) in fishes, however, only sporadic observations on the humoral immune responses have been made. Cadmium has been demonstrated to affect the immune system of teleost. The effects of sublethal concentrations of methylmercury and copper on the immune response of blue gourami (Trichogaster trichopterus) have also been studied. Attempts have been made to investigate the effect of the HCH and cadmium on the humoral immune responses to bacterial antigen using H. fossilis as test species. Attempt is also made to evaluate the vascular function at sublethal doses.

  11. Evasion of mucosal defenses during Aeromonas hydrophila infection of channel catfish (Ictalurus punctatus) skin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mucosal surfaces of fish serve as the first-line of defense against the myriad of aquatic pathogens present in the aquatic environment. The immune repertoire functioning at these interfaces is still poorly understood. The skin, in particular, must process signals from several fronts, sensing and...

  12. Early mucosal responses in blue catfish (Ictalurus furcatus) skin to Aeromonas hydrophila infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial pathogens are well-equipped to detect, adhere to, and initiate infection in their finfish hosts. The mucosal surfaces of fish, such as the skin, function as the front line of defense against such bacterial insults that are routinely encountered in the aquatic environment. While recent prog...

  13. Parasitism by protozoan Ichthyophthirius enhanced invasion of Aeromonas hydrophila in channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In aquaculture production mortality resulting from a single pathogen is rare. More likely, multiple disease agents are present and responsible for disease losses. The ciliated protozoan Ichthyophthirius multifiliis is a common parasite of freshwater fish and frequently causes mass kills of culture...

  14. DIFFERENTIATION OF AEROMONAS ISOLATES OBTAINED FROM DRINKING WATER DISTRIBUTION SYSTEM USING MATRIX-ASSISTED LASER DESCRIPTION/IONIZATION-MASS SPECTROMETRY (MALDI-MS)

    EPA Science Inventory

    The genus Aeromonas is one of several medically significant genera that have gained prominence due to their evolving taxonomy and controversial role in human diseases. In this study, matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was used to analyze the...

  15. THE USE OF MATRIX-ASSISTED LASER DESORPTION/IONIZATION-MASS SPECTROMETRY FOR THE IDENTIFICATION OF AEROMONAS ISOLATES OBTAINED FROM WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) has long been established as a tool by which microorganisms can be characterized and identified. EPA is investigating the potential of using this technology as a way to rapidly identify Aeromonas species fo...

  16. THE IDENTIFICATION OF THE WATER-BORNE PATHOGEN AEROMONAS USING WHOLE CELL ANALYSIS BY MATRIX ASSISTED LASER DESORPTION/IONIZATION-MASS

    EPA Science Inventory

    MALDI-MS has long been established as a tool by which microorganisms can be characterized and identified. The U.S. Environmental Protection Agency (EPA) is investigating the potential of using this technique as a way to rapidly identify Aeromonas species in drinking water. A nu...

  17. Behavior of Listeria monocytogenes and Aeromonas spp. on fresh-cut produce packaged under equilibrium-modified atmosphere.

    PubMed

    Jacxsens, L; Devlieghere, F; Falcato, P; Debevere, J

    1999-10-01

    Storage experiments were conducted to follow the behavior of pathogens on fresh-cut vegetables (trimmed brussels sprouts, grated carrots, shredded iceberg lettuce, and shredded chicory endives) packaged under an equilibrium-modified atmosphere (EMA) (2 to 3% O2, 2 to 3% CO2, and 94 to 96% N2) and stored at 7 degrees C. As a comparison, fresh-cut vegetables were also packaged in a perforated high-barrier film (air conditions) and stored at 7 degrees C. In a first step, the shelf life of the vegetables in the two kinds of packages was determined by evaluating the microbiological quality as well as the sensorial quality (appearance, taste, and odor). In general, sensorial properties were faster in limiting the shelf life than microbiological criteria. The shelf life of the vegetables stored under an EMA was extended by 50% or more, compared with the air-stored vegetables. In a second storage experiment, the four fresh-cut vegetables were inoculated with a cocktail of psychrotrophic pathogens (Listeria monocytogenes, Aeromonas caviae [HG4]) and A. bestiarum (HG2) before packaging under an EMA and air at 7 degrees C. The inoculated pathogens were more influenced by the type of vegetable than by the type of atmosphere. No growth was detected on the brussels sprouts or on carrots (L. monocytogenes). Aeromonas spp. had a higher growth rate than L. monocytogenes on the shredded chicory endives and shredded iceberg lettuce at 7 degrees C. PMID:10528715

  18. Effect of Diuron on aquatic bacteria in laboratory-scale wastewater treatment ponds with special reference to Aeromonas species studied by colony hybridization.

    PubMed

    Sumpono; Perotti, P; Belan, A; Forestier, C; Lavedrine, B; Bohatier, J

    2003-01-01

    Six laboratory-scale wastewater treatment ponds were filled with sediment and water obtained from a reference pond (a wastewater treatment plant located in a rural environment at Montel-de-Gelat, Puy-de-Dôme, France). They were kept at 20 degrees C, with alternative light and dark periods (12 h-12 h), and fed with raw effluent supplied weekly. Three of them were treated with Diuron (dissolved in DMSO) at a final concentration 10 mg/l, while the other three received only DMSO. Physico-chemical parameters, total bacteria, cultivable bacteria, and Aeromonas spp. were measured periodically until 41 days after the Diuron contamination. Total bacteria were treated with 4,6-diamidino 2-phenylindole (DAPI) and counted by epifluoroscence microscopy. The cultivable bacteria were quantified on plate count agar medium and Aeromonas spp. using colony hybridization. In the contaminated pilots, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), suspended solids (SS), volatile suspended solids (VSS), ammonium, phosphorus, and bacteria increased, but dissolved oxygen decreased. The abundance of total bacteria, cultivable bacteria (multiplied by 30), and Aeromonas spp. increased for two weeks after Diuron introduction, reverting to initial values three weeks later. The percentage of cultivable bacteria relative to total bacteria was 0.2% in controls and 1.2% in treated pilots, while the percentage of Aeromonas spp. relative to cultivable bacteria decreased from 6-10% to 2%. Our results suggest that Diuron, which acts on the photosystem II of phototrophs, supports the development of cultivable bacteria through new carbon sources derived from the decomposition of photosynthetic micro-organisms, but does not specifically support Aeromonas spp. PMID:12656266

  19. Selective culturing and genus-specific PCR detection for identification of Aeromonas in tissue samples to assist the medico-legal diagnosis of death by drowning.

    PubMed

    Huys, Geert; Coopman, Vera; Van Varenbergh, Dirk; Cordonnier, Jan

    2012-09-10

    The detection of autochthonous aquatic bacteria in tissue samples from drowning cases is increasingly considered as an alternative approach to assist the medico-legal diagnosis of death by drowning. Bacteria belonging to the genus Aeromonas may be suitable candidates for this application as they are ubiquitous in natural aquatic environments but are generally not part of the human microbiota. The research aims of this study were (i) to develop a sensitive, specific and rapid screening and confirmation method for Aeromonas species in tissue samples and (ii) to evaluate aseptic sternal puncture as a post-mortem sample technique and bone marrow as an alternative matrix to provide evidence of death by drowning. The presence of Aeromonas in tissue samples was verified by cultivation using the selective media Ampicillin Dextrin Agar (ADA) and Ryan's Aeromonas Medium. The use of ADA medium was found most optimal for the sensitive, inexpensive and quick detection of aeromonads in human tissue samples. Positive culture plates were confirmed by harvesting all colonies for DNA extraction and subsequent PCR amplification using Aeromonas genus-specific primers. Aeromonads were detected in lung swab, blood and bone marrow of drowned bodies (n=3), but were negative in these three matrices for all negative controls (n=90) tested. Bone marrow proved to be a suitable alternative matrix and can be sampled post-mortem by an aseptic sternal puncture. In conclusion, this study confirms previous indications that aeromonads in cultures from blood of water bodies can be considered a potential marker for drowning. Given the fact that the number of immersed bodies (drowned and non-drowned) included in this study is statistically not significant, however, more tissue samples need to be investigated to confirm the validity of these methods to aid the diagnosis of death by wet drowning. PMID:22497704

  20. Exposure to pairs of Aeromonas strains enhances virulence in the Caenorhabditis elegans infection model

    PubMed Central

    Mosser, Thomas; Talagrand-Reboul, Emilie; Colston, Sophie M.; Graf, Joerg; Figueras, Maria J.; Jumas-Bilak, Estelle; Lamy, Brigitte

    2015-01-01

    Aeromonad virulence remains poorly understood, and is difficult to predict from strain characteristics. In addition, infections are often polymicrobial (i.e., are mixed infections), and 5–10% of such infections include two distinct aeromonads, which has an unknown impact on virulence. In this work, we studied the virulence of aeromonads recovered from human mixed infections. We tested them individually and in association with other strains with the aim of improving our understanding of aeromonosis. Twelve strains that were recovered in pairs from six mixed infections were tested in a virulence model of the worm Caenorhabditis elegans. Nine isolates were weak worm killers (median time to death, TD50, ≥7 days) when administered alone. Two pairs showed enhanced virulence, as indicated by a significantly shortened TD50 after co-infection vs. infection with a single strain. Enhanced virulence was also observed for five of the 14 additional experimental pairs, and each of these pairs included one strain from a natural synergistic pair. These experiments indicated that synergistic effects were frequent and were limited to pairs that were composed of strains belonging to different species. The genome content of virulence-associated genes failed to explain virulence synergy, although some virulence-associated genes that were present in some strains were absent from their companion strain (e.g., T3SS). The synergy observed in virulence when two Aeromonas isolates were co-infected stresses the idea that consideration should be given to the fact that infection does not depend only on single strain virulence but is instead the result of a more complex interaction between the microbes involved, the host and the environment. These results are of interest for other diseases in which mixed infections are likely and in particular for water-borne diseases (e.g., legionellosis, vibriosis), in which pathogens may display enhanced virulence in the presence of the right partner. This