Electron microscopy of particles associated with a bacteriocinogenic Vibrio cholerae strain

Vibrio spp. and Their Vibriocin as a Vibriosis Control Measure in Aquaculture

Vibriosis disease is a major threat to the aquaculture industry caused by Vibrio spp. that are often resistant to antibiotics. Alternative controlling measures such as bacteriocins could be effective due to their narrow-spectrum activity. Hence, this systematic literature review (SLR) was carried out to review the feasibility of Vibrio spp. and their vibriocins to be used as a vibriosis control measure in aquaculture. A literature search using the web of science (WOS) and SCOPUS databases resulted in 42 unique articles which were reviewed. The results showed that Vibrio spp. could be used as a probiotic to control vibriosis, but not recommended due to their opportunistic nature and pathogenesis. Vibriocin showed narrow-spectrum activity against Vibrio spp. including highly pathogenic strains such as V. alginolyticus, V. harveyi, and V. parahaemolyticus. This supported this review's hypothesis of using vibriocin as a targeted vibriosis control measure. Vibrio cholerae was the most studied and showed the highest inhibition range, inhibiting 13 different vibrio and non-vibrio species. Various innovations were reported in the field and vibriocins can now be produced on large scales using whole-cell culture. Vibriocins were structurally diverse, large molecular weight, and relatively heat stable. These vibriocins mainly inhibited the cell wall but could have other novel mechanisms. These properties could affect the extraction process as well as applications in aquaculture, hence, should be considered in future research.

Genetic mapping of a defective bacteriophage on the chromosome of Bacillus subtilis 168

A genetic marker responsible for the killing activity of PBSX, a defective phage carried by Bacillus subtilis 168, has been located on the bacterial chromosome. Two mutant strains of B. subtilis 168, which produced tailless phage particles upon mitomycin C induction, were shown to carry lesions, designated xtl-1 and xtl-2, which were linked by transformation and PBS1-mediated transduction to metC. The link-age relationship between xtl and adjacent auxotrophic markers was determined by three-factor PBS1 transduction, the suggested order of markers being argO 1 metA metC xtl.

Production of Bacteriophage-Associated Materials by Vibrio cholerae : Possible Correlation with Pathogenicity

Classical and El Tor strains of Vibrio cholerae were examined for production of bacteriophage or bacteriophage-related material by electron microscopy of mitomycin C-induced cultures. The strains were also tested for pathogenicity by using the ligated ileal loops of adult rabbits. Of the 27 strains tested, 25 showed a correlation between the production of bacteriophage-related material and pathogenicity. Both P + and P − strains produced bacteriophage tails. The bacteriophage tails of strains 569B and ATCC 9168 and other strains were shown to occur in an extended form with tail appendages.

New method for the detection of a lethal factor in vibrios

When vibriocinogenic vibrios were mixed with an indicator strain, "lacunas" (plaquelike clearings) were observed, thus providing a new method for detection of vibriocins.