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Lectin-binding properties of Aeromonas caviae strains
Rocha-de-Souza, Cláudio M.;Hirata-Jr, Raphael;Mattos-Guaraldi, Ana L.;Freitas-Almeida, Angela C.;Andrade, Arnaldo F. B.;
Brazilian Journal of Microbiology , 2008, DOI: 10.1590/S1517-83822008000200003
Abstract: 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 37oc. on the other hand, specific receptors for wga and eel were completely abrogated growing the bacteria at 22oc. 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.
Effects of Aeromonas caviae co-cultured in mouse small intestine
Longa-Brice?o,Aurora; Pe?a-Contreras,Zulma; Dávila-Vera,Delsy; Mendoza-Brice?o,Rosa Virginia; Palacios-Prü,Ernesto;
Interciencia , 2006,
Abstract: the ultrastructural aspects generated by the interaction between two strains of aeromonas caviae with mouse intestinal mucosa are described. one of the strains was isolated from an asymptomatic patient and the other one from a patient with diarrhea. both strains were separately inoculated in closed cylinders of mouse small intestine and the whole preparations were incubated in eagle?s culture medium. the intestinal cylinders were divided into two groups, one was incubated for 24h and the other for 48h. samples of the co-cultures were processed for analysis using high resolution light microscopy and transmission electron microscopy. the strain isolated from the asymptomatic patient showed variable alterations in the intestinal mucosa, according to the different periods of incubation, whereas the one obtained from the patient with diarrhea always produced severe enteropathogenic effects
Cloning and Sequence Analysis of aha1 Gene Encoding Major Adhesin Protein from Aeromonas sp. Isolated from Aquaculture Animals with Haemorrhagic Septicemia
W. Wang,L. Wang,J.N. Li,M. Zhang
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2012.3908.3913
Abstract: Nine bacterial strains (LA1, LA2, LA4, JA1, CA3, CA4, BA1, BA18 and EA9) were isolated from different aquaculture animals with haemorrhagic septicemia and then they were identified as A. hydrophila (LA4, JA1, CA3 and BA1), A. sobria (LA1 and EA9), A. caviae (BA18) and A. veronii (CA4 and LA2), respectively by morphological and biochemical characterization. All isolates were found to be pathogenic to experimental zebrafish (Danio rerio) by artificial infection test. The outer membrane protein Aha1 is a major adhesin of A. hydrophila and also highly conserved in different serotypes of A. hydrophila. In order to ascertain the conservation of aha1 protein among mesophilic motile aeromonads, full length aha1 gene from all isolates was detected, cloned and sequenced. As the results show, the aha1 genes were amplified in all strains and the ORF size of the aha1 gene from A. hydrophila and other phenotypic species of aeromonas isolates was 1,068 and 1,038 bp, respectively. Four Anhui A. hydrophila isolates and six A. hydrophila reference strains formed a cluster together with 91.4-99.7% nucleotide identity and 91.9-99.7% amino acid identity of the aha1 gene. Five Anhui other phenotypic species isolates formed another cluster, they shared 79.5-81.1% nucleotide identity and 79.6-81.6% amino acid identity of the aha1 gene compared with A. hydrophila and the major sequence variations were observed between amino acids 85-134, 176- 227, 243-263, 280-295 and 321-336.
Purification, Characterization and Gene Cloning of High-molecular-weight Xylanase-4 of Aeromonas caviae W-61  [PDF]
Narayan Roy,Naoko Okai,Yoshiyuki Kamio
Pakistan Journal of Biological Sciences , 2001,
Abstract: Aeromonas caviae W-61 produces multiple extracellular xylanases, the xylanases 1, 2, 3, 4, and 5. In this study, we purified and characterized the xylanase-4 gene of A. caviae W-61, and cloned it. The purified xylanase-4 consisted of a single polypeptide with molecular masses of 120 kDa. The xylanases 4 was endo- -1,4-xylanase with optimum temperature 40°C, optimum pH 6.0 and temperature stability 40-50 C. Various xylo-oligosaccharides such as xylobiose, xylotriose, xylotetraose, xylopentaose and xylohexaose were formed, and a small amount of xylose was detected as the hydrolysis products. The N-terminal amino acid sequence and several identical internal amino acid sequences of xylanases-4 were determined. From the sequence, 1.8 kbp xyn 4 was amplified by PCR and was cloned from the genomic DNA of A. caviae W-61. The flanking region of xylanase-4 were sequenced and it contained a sequence corresponding a typical signal peptide consisting of 27 amino acid residues at the 5` end. Putative promotor ( 35 and 10) sequences and a typical ribosome-binding sequence were present upstream the xyn 4
Isolation and identification of Aeromonas caviae from Eriocheir sinensis

XU Hai-sheng,HUANG Li-feng,WANG Shu-xia,

浙江大学学报(农业与生命科学版) , 2001,
Abstract: Two strains of bacteria were isolated from haemolymph, liver, ascites and muscle of the diseased Eriocheir sinensis, which were cultured in the ponds in Zhuantang, Hangzhou. Both of the isolates were Gram-negative rods, motile by means of single polar flagella, and were facultatively anaerobic. Glucoce was catabolized with production of acid and no gas. Oxidase, Esculin, Catalase were positive, and nitrite was prodused from nitrate. Morpholohic, physiological and biochemical characteristics of the present isolates were the same as those of Aeromonas caviae, therefore, the pathogens isolated from the diseased Eriocheir sinensis were identified as Aeromonas caviae. The mortality of artificial infection was 100% , which ascertained that the bacterial isolates were the pathogens of the Eriocheir sinensis. The pathogens were highly sensitive to streptomycin, kanamycin, neomycin, ciprofloxacin, norfloxacin, chloramphenical, gentamicin, tobramycin, ofloxacin, ceftazidime, cefuroxime, ceftriaxone, nalidixic acid, nitrofurantoin.
Evaluation of Morphological Changes of Aeromonas caviae Sch3 Biofilm Formation under Optimal Conditions  [PDF]
Erika Beatriz Angeles-Morales, Ricardo Mondragón-Flores, Juan Pedro Luna-Arias, Cinthia Teresa Enríquez-Nieto, Berenice Parra-Ortega, Graciela Castro-Escarpulli
Advances in Microbiology (AiM) , 2012, DOI: 10.4236/aim.2012.24071

Aeromonas is a Gram-negative bacterium that lives in aquatic habitats. It can be infective in humans. One of its remarkable attributes is the ability of biofilm formation. Many factors are involved in the construction of biofilms as has been described for Pseudomonas, Klebsiella, and Vibrio, among others. The aim of this work was to study the bacterial morphology during the establishment of biofilm through scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with a modified microtiter plate assay and to determine the best conditions for the establishment of Aeromonas caviae Sch3 biolfilm in vitro. We observed several phenotypic changes, including surface appearance, size, presence of extracellular vesicles from 100 to 250 nm in diameter, and flagella. The best conditions for biofilm formation were to grow cultures at 28℃ at pH 6, as determined by the crystal violet assay. This is, to the best of our knowledge, the first study that describes the cell’s biological events involved in the establishment of biofilm formation of Aeromonas caviae Sch3 in vitro.

Occurrence of potential pathogenic Aeromonas species in tropical seafood, aquafarms and mangroves off Cochin coast in South India  [cached]
Alphonsa Vijaya Joseph,Raghul Subin Sasidharan,Harisree P Nair,Sarita G Bhat
Veterinary World , 2013, DOI: 10.5455/vetworld.2013.300-306
Abstract: Background: The genus Aeromonas include gram-negative, motile, facultative anaerobic, rod shaped and oxidase positive bacteria comprising several species, associated with the aquatic environment. Aeromonas species have been implicated in human pathogenesis and are linked with gastroenteritis, muscle infections, septicemia, and skin diseases. In fish they are renowned as enteric pathogens causing haemorrhagic septicemia, fin rot, soft tissue rot and furunculosis resulting in major die-offs and fish kills. Aim: This study reports the occurrence of potential pathogenic Aeromonas sp. in tropical seafood (Squids, Prawns and Mussels), aquafarms and mangroves of Cochin, Kerala, South India. Materials and Methods :Tropical seafood (Squid, Prawn and Mussel), sediment and water samples from aquafarms and associated mangroves were screened for Aeromonas contamination. The isolates were identified by 16S rDNA sequence analysis and subjected to morphological and biochemical characterization. Haemolytic assay was used for determining pathogenicity of the organisms. Antibiotic susceptibility against 12 antibiotics were performed and the MAR index was calculated. Results: A total of 134 isolates were recovered from the samples of which 15 were identified as Aeromonas species by 16S rDNA sequence analysis and were assigned to 5 species namely, A. hydrophila, A. enteropelogenes, A. caviae, A. punctataand A. aquarorium. Morphological, biochemical and phylogenetic analyses revealed relatedness and variability among the strains. All the isolates were haemolytic on blood agar indicating their pathogenicity. The isolates exhibited varying degrees of resistance to vancomycin (86.66%), ampicillin (46.66%), nalidixic acid (20%), tetracycline (6.66%), co-trimaxozole (6.66%) and rifampicin (6.66%) and were susceptible to antibiotics like gentamycin, streptomycin, trimethoprim, azithromycin, cefixime and chloramphenicol. 20% of Aeromonas sp. showed MAR index > 0.2 indicative of the high risk environment. Conclusion: The presence of Aeromonas sp. has been recognised as a potential health risk and surveillance of this pathogen is crucial for successful disease management and control. [Vet World 2013; 6(6.000): 300-306]
南方鲇(Silurus meridionalis)豚鼠气单胞菌溶血素的分离、纯化与致病性研究

WANG Kai-Yu,XIAO Dan,HE Yang,CHEN De-Fang,GENG Yi,LIU Tian-Qiang,HUANG Guan-Jun,
,肖 丹,贺 扬,陈德芳,耿 毅,刘天强,黄冠军

海洋与湖沼 , 2012,
Abstract: The haemolysin produced by Aeromonas caviae was salted out by ammonium sulphate precipitation and purified by chromatography on Sephadex A50. It was estimated to a homogeneous polypeptide of 32.2kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Haemolysis assay showed that its haemolytic activity was 25. To investigate its pathogenicity, double dilution haemolysin was intraperitoneally injected into Silurus meridionalis Chen. The results showed that the purified haemolysin was toxic towards S. meridionalis, with a half-lethal dose (LD50) of 0.29mg/kg (protein/weight). Fish injected with this haemolysin exhibited symptoms of color fading, abdominal intumescence, congestion and enlargement of liver and spleen, renomegaly, gastrointestinal inflammation. Skeletal muscle appeared swollen and disruption with red stained sarcoplasm. Liver corroded to cell death and necrosis, and were congested with few sinusoid. Degeneration and necrosis was found in the renal cells, which could extend to some histolysis. Renal interstitium showed a reduced incidence of lymphocytes with numerous inflammatory cells infiltration. Spleen lymphocytes were reduction. The epithelial cells of gastrointestinal tract mucoa developed symptoms of degeneration, necrosis and desquamation.
Isolation and Antibiotic Profile of Aeromonas Species from Tilapia Fish (Tilapia nilotica) and Catfish (Clarias betrachus)  [PDF]
A.W. Ashiru,P.O. Uaboi-Egbeni,J.E. Oguntowo,C.N. Idika
Pakistan Journal of Nutrition , 2011,
Abstract: In this study, the surface and the intestinal tract of catfish and tilapia fish purchased from Makoko market, Lagos metropolis in Nigeria were analyzed for the presence of Aeromonas species and their susceptibility to antibiotics was determined. The surface and intestinal tract of the fishes were found to be contaminated with Aeromonas species (Aeromonas caviae, Aeromonas hydrophila and Aeromonas sobria) and this is a potential risk for public health. Aeromonas caviae was predominant in tilapia fish while Aeromonas hydrophila and Aeromonas sobria were predominant in catfish. The Aeromonas species exhibited different level of antibiotics susceptibility based on the zone of inhibition observed around the antibiotics disc. Aeromonas caviae, Aeromonas sobria and Aeromonas hydrophila were all resistant to tetracycline, nitrofurantoin and augmentin with an average zone of inhibition of 9mm, 10mm and 8mm respectively but highly susceptible to pefloxacin, ofloxacin and ciprofloxacin with an average zone of inhibition of 17 mm, 21 mm and 24 mm respectively while they were randomly susceptible to ceftriazone, gentamycin, cotrimozazole and amoxycillin. Hence, pefloxacin, ofloxacin and ciprofloxacin are suitable drugs that can be use in the treatment of Aeromonas associated infections. There is need for antibiotic susceptibility test before treatment of Aeromonas associated infection since some strains of the Aeromonas species were randomly susceptible to the some of the antibiotics.
The Main Aeromonas Pathogenic Factors  [PDF]
J. M. Tomás
ISRN Microbiology , 2012, DOI: 10.5402/2012/256261
Abstract: 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. 1. Introduction Ever since the first reference of an organism that could be considered a motile aeromonad in 1891 the taxonomy of the genus Aeromonas, initiated in 1943, is complex and continuously changing. Although historically the genus Aeromonas was included in the family Vibrionaceae, together with the genera Vibrio, Photobacterium, and Plesiomonas, phylogenetic investigations indicated that they should form their own family: Aeromonadaceae [1]. The family Aeromonadaceae consists of Gram-negative, facultative anaerobic, chemoorganotroph bacteria with an optimal growing temperature of about 22°C to 28°C. Generally they are motile by polar flagellation, able to reduce nitrates to nitrites and able to catabolize glucose and several carbohydrates while producing acids and often gases as well. Initially, in Bergey’s Manual of Systematic Bacteriology this family only included the genus Aeromonas and was divided into two principal subgroups: the nonmotile and psycnrophilic species (A. salmonicida) and the motile and mesophilic species (A. hydrophila, A. caviae, and A. sobria) [2]. The current edition, list three genera in this family: Aeromonas, Oceanimonas, and Tolumonas [3]. The first classifications within the Aeromonas genus have been determined phenotypically (phenospecies), based on growth characteristics and biochemical tests. Nevertheless, there is a great difficulty in identifying the different Aeromonas strains on a species level by these characteristics, due to the phenotypical heterogeneity and growing number of known species [4]. One of the
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