Identification of Pathogenic Fish Bacteria Using the API ZYM System

1993 ◽  
Vol 50 (6) ◽  
pp. 1137-1141 ◽  
Author(s):  
Masahiro Sakai ◽  
M. K. Soliman ◽  
T. Yoshida ◽  
Masanori Kobayashi

The API ZYM system was used to identify the bacterial fish pathogens Enterococcus seriolicida, β-hemolytic Streptococcus sp., Renibacterium salmoninarum, Aeromonas salmonicida, A. hydrophila, Pasteurella piscicida, Edwardsiella tarda, Vibrio anguillarum, Pseudomonas fluorescens, Flexibacter columnaris, and F. maritimus. As additional tests, Gram stain and the activities of cytochrome oxidase and catalase were examined. The results of APS ZYM and the additional tests were coded for easy identification. Several biotypes were demonstrated by Streptococcus sp., V. anguillarum, and A. hydrophila. Other bacteria showed uniform profiles. This system can distinguish each fish pathogen from all other bacterial species examined.

1993 ◽  
Vol 39 (6) ◽  
pp. 581-587 ◽  
Author(s):  
Declan Maher ◽  
Diane E. Taylor

HI plasmids are distinguished by their thermosensitive mode of conjugation (transfer efficiency is optimal at 22–30 °C) and their capacity to encode multiple antibiotic resistance. These traits have implicated HI plasmids as potential vectors in the dissemination of antibiotic resistance among pathogenic and indigenous bacterial species in water and soil environments. We compared the transfer efficiency of HI plasmids with that of plasmids from 13 other incompatibility groups at 37, 24, and 14 °C in intragenic conjugations between laboratory strains of Escherichia coli K-12 under in vitro conditions. Only the HI plasmids and a representative plasmid from incompatibility groups M, N, Pα, T, and W were observed to be transmissible at 14 °C. These plasmids, along with HI plasmids and the related HII representative, were tested for their host range and transfer proficiency to Enterobacteria species and some other Gram-negative organisms of environmental significance at 24 and 14 °C. Notable differences in the host range of HI plasmids compared with plasmid representatives from the other enterobacterial groups were not evident at 24 °C. At 14 °C, R478 (HI2) displayed the broadest host range and transfer proficiency among the test plasmids. The ability of several plasmid groups, including HI, to transfer at 14–24 °C to Vibrio cholerae non 01, Salmonella typhi, and the fish pathogens Aeromonas salmonicida, Vibrio anguillarum, and Yersinia ruckeri needs to be corroborated by in situ studies.Key words: conjugation, plasmids, thermosensitive transfer, host range.


1977 ◽  
Vol 34 (8) ◽  
pp. 1244-1249 ◽  
Author(s):  
G. L. Bullock ◽  
H. M. Stuckey

Filtration (25 nm) and ultraviolet irradiation dosages of 13,100–29,400 microwatt seconds per square centimetre (μW∙s∙cm−2) effected a 99.98–100% reduction of five gram-negative fish pathogens — Aeromonas salmonicida, A. hydrophila, Vibrio anguillarum, Pseudomonas fluorescens, and the enteric redmouth organism in 12.5 °C clear spring water or spring water containing particulate matter. Filtration and a dosage of 4500 μW∙s∙cm−2 killed 99.83–100% of test strains in spring water and 4000–4750 μW∙s∙cm−2 killed 99.33–99.99% in water with particulate matter. Irradiation of unfiltered water containing particulate matter was less effective, especially at dosages of 5000 μW∙s∙cm−2 or less, which killed 97–99.94% of strains. Filtration and 13,100 μW∙s∙cm−2 irradiation of water containing A. salmonicida prevented transmission of furunculosis. Key words: ultraviolet irradiation, bacterial fish pathogens, water disinfection


2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Maki Teramoto ◽  
Zhenyu Zhai ◽  
Ayumi Komatsu ◽  
Keigo Shibayama ◽  
Masato Suzuki

Some bacterial species of the genus Tenacibaculum , including Tenacibaculum ovolyticum , have been known as fish pathogens in the sea. So far, the only published genome sequence for this genus is for Tenacibaculum dicentrarchi , which could also be a fish pathogen. Strain da5A-8, showing 100% identity to the 16S rRNA gene sequence of T. ovolyticum DSM 18103 T , was isolated from seawater at a depth of 344 m in Kochi, Japan, and grew optimally at 10 to 20°C. The genome sequence of strain da5A-8 revealed the possible virulence genes commonly observed in the genus Tenacibaculum .


2008 ◽  
Vol 52 (No. 2) ◽  
pp. 49-53 ◽  
Author(s):  
N. Topic Popovic ◽  
R. Coz-Rakovac ◽  
I. Strunjak-Perovic

The available data concerning rapid identification of fish bacteria via commercial phenotypic tests demonstrate that there is no agreement regarding the choice of the tests. However, API 20E, an identification system for Enterobacteriaceae and other non-fastidious Gram-negative rods developed for clinical specimens, seems to be increasingly used for the identification of fish pathogens. In this review, adaptation of API 20E for fish bacterial isolates and its distinctiveness for fish bacteria was assessed. Some strains are wrongly identified because they are not included in the database of API 20E system. API 20E reactions should be compared with the diagnostic schemes based on reactions in conventional phenotypic tests. Due to their significance for fish health and impact on the aquaculture, and because of the need for their rapid identification, some important fish bacteria should be included in the API 20E system, such as <i>Yersinia ruckeri</i>, <i>Edwardsiella ictaluri</i>, <i>Vibrio anguillarum</i>.


2009 ◽  
Vol 418 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Claudia S. López ◽  
R. Sean Peacock ◽  
Jorge H. Crosa ◽  
Hans J. Vogel

In the fish pathogen Vibrio anguillarum the TonB2 protein is essential for the uptake of the indigenous siderophore anguibactin. Here we describe deletion mutants and alanine replacements affecting the final six amino acids of TonB2. Deletions of more than two amino acids of the TonB2 C-terminus abolished ferric-anguibactin transport, whereas replacement of the last three residues resulted in a protein with wild-type transport properties. We have solved the high-resolution solution structure of the TonB2 C-terminal domain by NMR spectroscopy. The core of this domain (residues 121–206) has an αββαβ structure, whereas residues 76–120 are flexible and extended. This overall folding topology is similar to the Escherichia coli TonB C-terminal domain, albeit with two differences: the β4 strand found at the C-terminus of TonB is absent in TonB2, and loop 3 is extended by 9 Å (0.9 nm) in TonB2. By examining several mutants, we determined that a complete loop 3 is not essential for TonB2 activity. Our results indicate that the β4 strand of E. coli TonB is not required for activity of the TonB system across Gram-negative bacterial species. We have also determined, through NMR chemical-shift-perturbation experiments, that the E. coli TonB binds in vitro to the TonB box from the TonB2-dependent outer membrane transporter FatA; moreover, it can substitute in vivo for TonB2 during ferric-anguibactin transport in V. anguillarum. Unexpectedly, TonB2 did not bind in vitro to the FatA TonB-box region, suggesting that additional factors may be required to promote this interaction. Overall our results indicate that TonB2 is a representative of a different class of TonB proteins.


2013 ◽  
Vol 16 (4) ◽  
pp. 273-277 ◽  
Author(s):  
Geon-A Jo ◽  
Sae-Bom Kwon ◽  
Na-Kyeong Kim ◽  
Muhammad Tofazzal Hossain ◽  
Yu-Ri Kim ◽  
...  

1993 ◽  
Vol 39 (11) ◽  
pp. 1051-1058 ◽  
Author(s):  
Rafael A. Garduño ◽  
Julian C. Thornton ◽  
William W. Kay

A model was developed to study the fate of the fish pathogen Aeromonas salmonicida in vivo, inside a specialized intraperitoneal chamber implanted in rainbow trout, Oncorhynchus mykiss. Although normally recalcitrant to lytic agents in vitro, owing to the presence of its regular surface array (S layer), A. salmonicida was rapidly killed in the peritoneal cavity by a host-derived, soluble lytic activity present in peritoneal fluid. Peritoneal fluid was also found to kill other bacteria and lyse various types of erythrocytes, but was particularly lytic to A. salmonicida. Intraperitoneal survival of injected (free) A. salmonicida cells was several orders of magnitude higher than survival of implanted (restrained) cells. Injected free cells could evade the lytic activity of peritoneal fluid because they readily spread, initiating lethal infections. One evasion strategy was envisioned to be the penetration of peritoneal and (or) tissue macrophages. In spite of the killing mechanisms of these phagocytic cells, A. salmonicida was still able to survive and even replicate inside head kidney macrophages, thereby supporting the notion of A. salmonicida as a facultatively intracellular pathogen. Intraperitoneal chambers in rainbow trout may constitute a valuable experimental tool for studying the in vivo fate of A. salmonicida, and perhaps of other fish pathogens as well.Key words: Aeromonas salmonicida, intraperitoneal chambers, rainbow trout, complement-mediated cell lysis.


Author(s):  
Antony T Vincent ◽  
Laurent Intertaglia ◽  
Victor Loyer ◽  
Valérie E Paquet ◽  
Émilie Adouane ◽  
...  

Abstract Genomic islands (Aeromonas salmonicida genomic islands, AsaGEIs) are found worldwide in many isolates of Aeromonas salmonicida subsp. salmonicida, a fish pathogen. To date, five variants of AsaGEI (1a, 1b, 2a, 2b and 2c) have been described. Here, we investigate a sixth AsaGEI, which was identified in France between 2016 and 2019 in 20 A. salmonicida subsp. salmonicida isolates recovered from sick salmon all at the same location. This new AsaGEI shares the same insertion site in the chromosome as the other AsaGEI2s as they all have a homologous integrase gene. This new AsaGEI was thus named AsaGEI2d, and has 5 unique genes compared to the other AsaGEIs. The isolates carrying AsaGEI2d also bear the plasmid pAsa7, which was initially found in an isolate from Switzerland. This plasmid provides resistance to chloramphenicol thanks to a cat gene. This study reveals more about the diversity of the AsaGEIs.


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