Aeromonas hydrophila: Variability in biochemical characteristics of environmental isolates

SummaryFaecal samples from 110 horses, 115 pigs, 111 sheep and 123 cows were examined for the presence ofAeromonas 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 ofA. hydrophilafrom 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 ofA. hydrophilawere resistant to amoxycillin, carbenicillin and cephradine, and sensitive to gentamicin, chloramphenicol and neomycin.

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PCR Detection, Characterization, and Distribution of Virulence Genes in Aeromonas spp

Applied and Environmental Microbiology ◽

10.1128/aem.65.12.5293-5302.1999 ◽

1999 ◽

Vol 65 (12) ◽

pp. 5293-5302 ◽

Cited By ~ 107

Author(s):

Cesar Isigidi Bin Kingombe ◽

Geert Huys ◽

Mauro Tonolla ◽

M. John Albert ◽

Jean Swings ◽

...

Keyword(s):

Aeromonas Hydrophila ◽

Virulence Genes ◽

Fragment Length Polymorphism ◽

Environmental Isolates ◽

Specific Primers ◽

Group 4 ◽

Pcr Rflp ◽

The World ◽

Hybridization Group ◽

Reference Strains

ABSTRACT 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 ofAeromonas 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 fromAeromonas 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) withHpaII 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.

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Sequence Analysis of Amplified DNA Fragments Containing the Region Encoding the Putative Lipase Substrate-Binding Domain and Genotyping of Aeromonas hydrophila

Applied and Environmental Microbiology ◽

10.1128/aem.70.1.145-151.2004 ◽

2004 ◽

Vol 70 (1) ◽

pp. 145-151 ◽

Cited By ~ 3

Author(s):

Noboru Watanabe ◽

Koji Morita ◽

Tomoko Furukawa ◽

Taki Manzoku ◽

Eiko Endo ◽

...

Keyword(s):

Amino Acid ◽

Nucleotide Sequence ◽

Amino Acid Sequence ◽

Aeromonas Hydrophila ◽

Substrate Binding ◽

Binding Domain ◽

Dna Fragments ◽

Environmental Isolates ◽

Sequence Patterns ◽

Substrate Binding Domain

ABSTRACT DNA fragments were amplified by PCR from all tested strains of Aeromonas hydrophila, A. caviae, and A. sobria with primers designed based on sequence alignment of all lipase, phospholipase C, and phospholipase A1 genes and the cytotonic enterotoxin gene, all of which have been reported to have the consensus region of the putative lipase substrate-binding domain. All strains showed lipase activity, and all amplified DNA fragments contained a nucleotide sequence corresponding to the substrate-binding domain. Thirty-five distinct nucleotide sequence patterns and 15 distinct deduced amino acid sequence patterns were found in the amplified DNA fragments from 59 A. hydrophila strains. The deduced amino acid sequences of the amplified DNA fragments from A. caviae and A. sobria strains had distinctive amino acids, suggesting a species-specific sequence in each organism. Furthermore, the amino acid sequence patterns appear to differ between clinical and environmental isolates among A. hydrophila strains. Some strains whose nucleotide sequences were identical to one another in the amplified region showed an identical DNA fingerprinting pattern by repetitive extragenic palindromic sequence-PCR genotyping. These results suggest that A. hydrophila, and also A. caviae and A. sobria strains, have a gene encoding a protein with lipase activity. Homologs of the gene appear to be widely distributed in Aeromonas strains, probably associating with the evolutionary genetic difference between clinical and environmental isolates of A. hydrophila. Additionally, the distinctive nucleotide sequences of the genes could be attributed to the genotype of each strain, suggesting that their analysis may be helpful in elucidating the genetic heterogeneity of Aeromonas.

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Biochemical characteristics of clinical and environmental isolates of Burkholderia pseudomallei

Journal of Medical Microbiology ◽

10.1099/00222615-45-6-408 ◽

1996 ◽

Vol 45 (6) ◽

pp. 408-412 ◽

Cited By ~ 102

Author(s):

V. Wuthiekanun ◽

M. D. Smith ◽

D. A. B. Dance ◽

A. L. Walsh ◽

T. L. Pitt ◽

...

Keyword(s):

Burkholderia Pseudomallei ◽

Environmental Isolates ◽

Biochemical Characteristics

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Microtubule Dynamics and Organelle Transport in Reticulomyxa

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158510 ◽

1990 ◽

Vol 48 (3) ◽

pp. 194-195

Author(s):

Yih-Tai Chen ◽

Ursula Euteneuer ◽

Ken B. Johnson ◽

Michael P. Koonce ◽

Manfred Schliwa

Keyword(s):

Plasma Membrane ◽

Light Microscopy ◽

Cytoplasmic Dynein ◽

Living Cells ◽

Microtubule Dynamics ◽

Model Systems ◽

Organelle Transport ◽

Biochemical Characteristics ◽

Dependent Transport

The application of video techniques to light microscopy and the development of motility assays in reactivated or reconstituted model systems rapidly advanced our understanding of the mechanism of organelle transport and microtubule dynamics in living cells. Two microtubule-based motors have been identified that are good candidates for motors that drive organelle transport: kinesin, a plus end-directed motor, and cytoplasmic dynein, which is minus end-directed. However, the evidence that they do in fact function as organelle motors is still indirect.We are studying microtubule-dependent transport and dynamics in the giant amoeba, Reticulomyxa. This cell extends filamentous strands backed by an extensive array of microtubules along which organelles move bidirectionally at up to 20 μm/sec (Fig. 1). Following removal of the plasma membrane with a mild detergent, organelle transport can be reactivated by the addition of ATP (1). The physiological, pharmacological and biochemical characteristics show the motor to be a cytoplasmic form of dynein (2).

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