Host range and transfer efficiency of incompatibility group HI plasmids

1993 ◽  
Vol 39 (6) ◽  
pp. 581-587 ◽  
Author(s):  
Declan Maher ◽  
Diane E. Taylor
Keyword(s):  
Antibiotic Resistance ◽  
Host Range ◽  
Bacterial Species ◽  
Vibrio Anguillarum ◽  
Aeromonas Salmonicida ◽  
Transfer Efficiency ◽  
Yersinia Ruckeri ◽  
Fish Pathogens ◽  
K 12

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.

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
Keyword(s):  
Bacterial Species ◽  
Vibrio Anguillarum ◽  
Aeromonas Salmonicida ◽  
Edwardsiella Tarda ◽  
Gram Stain ◽  
Fish Pathogen ◽  
Fish Pathogens ◽  
Renibacterium Salmoninarum ◽  
Hemolytic Streptococcus ◽  
Fish Bacteria

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.

Ultraviolet Treatment of Water for Destruction of Five Gram-Negative Bacteria Pathogenic to Fishes

1977 ◽  
Vol 34 (8) ◽  
pp. 1244-1249 ◽  
Author(s):  
G. L. Bullock ◽  
H. M. Stuckey
Keyword(s):  
Particulate Matter ◽  
Ultraviolet Irradiation ◽  
Vibrio Anguillarum ◽  
Spring Water ◽  
Aeromonas Salmonicida ◽  
Water Disinfection ◽  
Gram Negative Bacteria ◽  
Fish Pathogens ◽  
Gram Negative ◽  
Ultraviolet Treatment

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

scholarly journals Efficiency of Phage φ6 for Biocontrol of Pseudomonas syringae pv. syringae: An in Vitro Preliminary Study

2019 ◽  
Vol 7 (9) ◽  
pp. 286 ◽  
Author(s):  
Larindja A. M. Pinheiro ◽  
Carla Pereira ◽  
Carolina Frazão ◽  
Victor M. Balcão ◽  
Adelaide Almeida
Keyword(s):  
Solar Radiation ◽  
Host Range ◽  
Pseudomonas Syringae ◽  
Bacterial Resistance ◽  
Phage Therapy ◽  
Bacterial Species ◽  
Fruit Trees ◽  
Range Analysis ◽  
Maximum Reduction

Pseudomonas syringae is a plant-associated bacterial species that has been divided into more than 60 pathovars, with the Pseudomonas syringae pv. syringae being the main causative agent of diseases in a wide variety of fruit trees. The most common treatments for biocontrol of P. syringae pv. syringae infections has involved copper derivatives and/or antibiotics. However, these treatments should be avoided due to their high toxicity to the environment and promotion of bacterial resistance. Therefore, it is essential to search for new approaches for controlling P. syringae pv. syringae. Phage therapy can be a useful alternative tool to the conventional treatments to control P. syringae pv. syringae infections in plants. In the present study, the efficacy of bacteriophage (or phage) φ6 (a commercially available phage) was evaluated in the control of P. syringae pv. syringae. As the plants are exposed to the natural variability of physical and chemical parameters, the influence of pH, temperature, solar radiation and UV-B irradiation on phage φ6 viability was also evaluated in order to develop an effective phage therapy protocol. The host range analysis revealed that the phage, besides its host (P. syringae pv. syringae), also infects the Pseudomonas syringae pv. actinidiae CRA-FRU 12.54 and P. syringae pv. actinidiae CRA-FRU 14.10 strains, not infecting strains from the other tested species. Both multiplicities of infection (MOIs) tested, 1 and 100, were effective to inactivate the bacterium, but the MOI 1 (maximum reduction of 3.9 log CFU/mL) was more effective than MOI 100 (maximum reduction of 2.6 log CFU/mL). The viability of phage φ6 was mostly affected by exposure to UV-B irradiation (decrease of 7.3 log PFU/mL after 8 h), exposure to solar radiation (maximum reduction of 2.1 PFU/mL after 6 h), and high temperatures (decrease of 8.5 PFU/mL after 6 days at 37 °C, but a decrease of only 2.0 log PFU/mL after 67 days at 15 °C and 25 °C). The host range, high bacterial control and low rates of development of phage-resistant bacterial clones (1.20 × 10−3) suggest that this phage can be used to control P. syringae pv. syringae infections in plants, but also to control infections by P. syringae pv. actinidiae, the causal agent of bacterial canker of kiwifruit. Although the stability of phage φ6 was affected by UV-B and solar radiation, this can be overcome by the application of phage suspensions at the end of the day or at night.

scholarly journals Adaptation in a Mouse Colony Monoassociated with Escherichia coli K-12 for More than 1,000 Days

2010 ◽  
Vol 76 (14) ◽  
pp. 4655-4663 ◽  
Author(s):  
Sean M. Lee ◽  
Aaron Wyse ◽  
Aaron Lesher ◽  
Mary Lou Everett ◽  
Linda Lou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rates ◽  
Bacterial Species ◽  
Intestinal Flora ◽  
Average Density ◽  
Host Bacterium ◽  
E Coli ◽  
K 12

ABSTRACT Although mice associated with a single bacterial species have been used to provide a simple model for analysis of host-bacteria relationships, bacteria have been shown to display adaptability when grown in a variety of novel environments. In this study, changes associated with the host-bacterium relationship in mice monoassociated with Escherichia coli K-12 over a period of 1,031 days were evaluated. After 80 days, phenotypic diversification of E. coli was observed, with the colonizing bacteria having a broader distribution of growth rates in the laboratory than the parent E. coli. After 1,031 days, which included three generations of mice and an estimated 20,000 generations of E. coli, the initially homogeneous bacteria colonizing the mice had evolved to have widely different growth rates on agar, a potential decrease in tendency for spontaneous lysis in vivo, and an increased tendency for spontaneous lysis in vitro. Importantly, mice at the end of the experiment were colonized at an average density of bacteria that was more than 3-fold greater than mice colonized on day 80. Evaluation of selected isolates on day 1,031 revealed unique restriction endonuclease patterns and differences between isolates in expression of more than 10% of the proteins identified by two-dimensional electrophoresis, suggesting complex changes underlying the evolution of diversity during the experiment. These results suggest that monoassociated mice might be used as a tool for characterizing niches occupied by the intestinal flora and potentially as a method of targeting the evolution of bacteria for applications in biotechnology.

scholarly journals Antimicrobial Peptides Protect Coho Salmon fromVibrio anguillarum Infections

2000 ◽  
Vol 66 (5) ◽  
pp. 1928-1932 ◽  
Author(s):  
X. Jia ◽  
A. Patrzykat ◽  
R. H. Devlin ◽  
P. A. Ackerman ◽  
G. K. Iwama ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Coho Salmon ◽  
Vibrio Anguillarum ◽  
Transgenic Fish ◽  
In Vivo Studies ◽  
Bacterial Disease ◽  
Control Groups ◽  
Fish Pathogens

ABSTRACT Fish losses from infectious diseases are a significant problem in aquaculture worldwide. Therefore, we investigated the ability of cationic antimicrobial peptides to protect against infection caused by the fish pathogen Vibrio anguillarum. To identify effective peptides for fish, the MICs of certain antimicrobial peptides against fish pathogens were determined in vitro. Two of the most effective antimicrobial peptides, CEME, a cecropin-melittin hybrid peptide, and pleurocidin amide, a C-terminally amidated form of the natural flounder peptide, were selected for in vivo studies. A single intraperitoneal injection of CEME did not affect mortality rates in juvenile coho salmon infected with V. anguillarum, the causative agent of vibriosis. Therefore, the peptides were delivered continuously using miniosmotic pumps placed in the peritoneal cavity. Twelve days after pump implantation, the fish received intraperitoneal injections ofV. anguillarum at a dose that would kill 50 to 90% of the population. Fish receiving 200 μg of CEME per day survived longer and had significantly lower accumulated mortalities (13%) than the control groups (50 to 58%). Fish receiving pleurocidin amide at 250 μg per day also survived longer and had significantly lower accumulated mortalities (5%) than the control groups (67 to 75%). This clearly shows the potential for antimicrobial peptides to protect fish against infections and indicates that the strategy of overexpressing the peptides in transgenic fish may provide a method of decreasing bacterial disease problems.

scholarly journals Commercial phenotypic tests (API 20E) in diagnosis of fish bacteria: a review

2008 ◽  
Vol 52 (No. 2) ◽  
pp. 49-53 ◽  
Author(s):  
N. Topic Popovic ◽  
R. Coz-Rakovac ◽  
I. Strunjak-Perovic
Keyword(s):  
Vibrio Anguillarum ◽  
Rapid Identification ◽  
Identification System ◽  
Bacterial Isolates ◽  
Yersinia Ruckeri ◽  
Fish Health ◽  
Fish Pathogens ◽  
Phenotypic Tests ◽  
Fish Bacteria ◽  
Important Fish

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>.

scholarly journals Molecular characterization of the TonB2 protein from the fish pathogen Vibrio anguillarum

2009 ◽  
Vol 418 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Claudia S. López ◽  
R. Sean Peacock ◽  
Jorge H. Crosa ◽  
Hans J. Vogel
Keyword(s):  
Amino Acids ◽  
Solution Structure ◽  
Bacterial Species ◽  
Vibrio Anguillarum ◽  
Fish Pathogen ◽  
E Coli ◽  
Terminal Domain ◽  
C Terminus

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.

scholarly journals Pharmacokinetics of chloramphenicol (CAP) in gilthead sea bream (Sparus aurata) and its in vitro activities against important bacterial fish pathogens

2017 ◽  
Vol 54 (4) ◽  
pp. 311 ◽  
Author(s):  
A. E. TYRPENOU (Α.Ε. ΤΥΡΠΕΝΟΥ) ◽  
G. RIGOS (Γ. ΡΗΓΟΣ) ◽  
M. YAGNISI (Μ. ΓΙΑΓΝΙΣΗ) ◽  
I. NENGAS (Ι. ΝΕΓΚΑΣ) ◽  
M. ALEXIS (Μ. ΑΛΕΞΗΣ)
Keyword(s):  
Half Life ◽  
Sparus Aurata ◽  
Vibrio Anguillarum ◽  
Central Compartment ◽  
Apparent Volume ◽  
Gilthead Sea Bream ◽  
Sea Bream ◽  
Farmed Fish ◽  
Fish Pathogens

The pharmacokinetics of chloramphenicol (CAP) in gilthead sea bream (Sparus aurata), a warm water farmed fish species and its in vitro efficacy against important bacterial diseases of Mediterranean mariculture were investigated in this study. After an intravascular injection (10 mg/kg/fish), the distribution half-life (tl/2a) and the elimination half-life (tl/2ß) of CAP were calculated to be 1.6 and 69 h, respectively. Tissue penetration of CAP was found to be moderate since both the apparent volume of distribution of the drug at steady-state (V<i(ss)) and the apparent volume of the central compartment (Vc) were calculated to be 1.13 and 0.90 L/kg. The total clearance (CLp) of the drug was slow (0.022 L/kg/h). The minimum inhibitory concentration (MIC) values of CAP in distilled water supplemented with 2% NaCl against Vibrio anguillarum serotype lb, Photobacterium damsela subsp. piscicida, V alginolyticus and V ßuvialis were determined to be 4.78 pg/mL, while it was 0.60 pg/mL for V. damsela. The addition of 10 mM Ca2+ and 55 mM Mg2+ in the medium revealed MIC values of 19.13 pg/mL for V alginolyticus and V ßuvialis, whereas showed no effect for V anguillarum P. damsela subsp. Piscicida and V damsela. The results indicate that CAP displayed a satisfactory kinetic profile and it is eliminated fast from gilthead sea bream muscle; however, its high MIC values stress show a possible inefficacy against important bacterial pathogens of Mediterranean mariculture.

scholarly journals Preliminary in vitro screening of the antibacterial activity of leaf extracts from various Ficus species (Moraceae) against Yersinia ruckeri

2019 ◽  
Vol 27 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Halyna Tkachenko ◽  
Lyudmyla Buyun ◽  
El¿bieta Terech-Majewska ◽  
Vitaliy Honcharenko ◽  
Andriy Prokopiv ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Yersinia Ruckeri ◽  
Leaf Extracts ◽  
Fish Pathogens ◽  
Promising Alternative ◽  
Ethanolic Extracts ◽  
Activity Screening

Abstract Remarkable progress in the field of antibacterial herbal therapy has been made in recent decades in response to the development of drug-resistant pathogens in aquaculture. Studies have focused on the in vitro antimicrobial activity screening of ethanolic extracts of various plants belonging to the genus Ficus. The aim of the present study was to evaluate the antibacterial efficacy of ethanolic extracts of various Ficus species against Yersinia ruckeri. In vitro tests for antibacterial activity revealed that ethanolic leaf extracts of various Ficus species and their cultivars offer a promising alternative to antibiotics and chemotherapeutics for controlling the growth of Y. ruckeri. In our study, ethanolic extracts obtained from leaves of F. natalensis subsp. leprieurii and F. macrophylla proved effective against a bacterial strain at a dose of 400 pl standardized inoculum (108 CFU ml−1). It should be noted that Y. ruckeri demonstrated an intermediate susceptibility to more extracts derived from the leaves of Ficus species. Our investigation showed that among the various Ficus species, ethanolic leaf extracts of ten Ficus species against Y. ruckeri were the most effective. The effect of the leaf extracts that expressed the highest antimicrobial activity (F. macrophylla, F. natalensis subsp. leprieurii) against Y. ruckeri was comparable to that of gentamicin. Therefore, preliminary screening indicated that the ethanolic leaf extracts of some Ficus species with antibacterial properties can be used in aquaculture as therapeutic and prophylactic agents against fish pathogens, including Y. ruckeri.

Fate of the fish pathogen Aeromonas salmonicida in the peritoneal cavity of rainbow trout

1993 ◽  
Vol 39 (11) ◽  
pp. 1051-1058 ◽  
Author(s):  
Rafael A. Garduño ◽  
Julian C. Thornton ◽  
William W. Kay
Keyword(s):  
Rainbow Trout ◽  
Peritoneal Cavity ◽  
Peritoneal Fluid ◽  
Aeromonas Salmonicida ◽  
Lytic Activity ◽  
Fish Pathogen ◽  
Phagocytic Cells ◽  
Fish Pathogens

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.

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