Bacterial Fish Pathogens Alsina et ai 1994 On VAM V anguillarum produced bright

Bacterial fish pathogens alsina et ai 1994 on vam v

This preview shows page 195 - 197 out of 594 pages.

Bacterial Fish Pathogens Alsina et ai, 1994). On VAM, V. anguillarum produced bright-yellow colonies with yellow haloes. Its usefulness was attested by its ability to recognise the majority, i.e. 197/227 = 87%, of V. anguillarum isolates. However, some erroneous results occurred insofar as VAM recognised 3/66 = 4% of other vibrios as V. anguillarum (Alsina et aL, 1994). Vibrio cholerae (non-Ol) This may be achieved by inoculating kidney material (from swabs) onto the surface of nutrient agar plates, with incubation at 25°C for an undisclosed period (presumably 2-5 days) (Muroga et ai, 1979; Kiiyukia et ai, 1992). Vibrio fischeri By use of TSA supplemented with 2% (w/v) sodium chloride, marine 2216E agar (Difco) and TCBS (Oxoid), virtual pure culture growth of bacteria was recovered from the kidney and liver, following incubation at an unstated temperature for an unspecified duration (Lamas et ai, 1990). Vibrio harveyi Samples of kidney and liver were inoculated into thioglycollate broth (Appendix 5.1), followed by single-colony isolation on plates of TSA supplemented with 1 % (w/v) sodium chloride (Grimes et ai, 1984a). Yii et al. (1997) used TSA supplemented with 2% (w/v) sodium chloride and TCBS with intestinal fluid from diseased grouper. Generally, the use of TSA, MacConkey agar, TCBS and cytophaga agar were advocated, with incubation at 25-35°C for 24-48 h. Thus according to Kraxberger- Beatty et al. (1990), the eyes were removed and homogenised in sterile saline, loopfuls of the material being streaked onto the agar-containing media. It should be empha- sised that attempts were not made to surface-sterilise the eyes. Therefore, the resulting homogenate would have also contained aquatic (saprophytic) bacteria, as well as any potential pathogen. It is unclear from the article describing V. trachuri how the organisms were isolated from fish (Iwamoto et ai, 1995). Vibrio logei Benediktsdottir et al. (1998) used 5% (v/v) horse blood agar supplemented with 1.5% (w/v) sodium chloride with incubation at 15°C for 7 days. Vibrio ordalii As with V. anguillarum, isolation involves use of seawater agar and TCBS with incubation at 15-25°C for up to 7 days (Ransom, 1978; Ransom et al, 1984).
Image of page 195
Isolation/Detection 173 Vibrio pelagius Samples from diseased tissues were inoculated onto TSA supplemented with 2% (w/v) sodium chloride, marine 2216E agar and TCBS with incubation at 25°C for 48 h (Angulo et al, 1992). Vibrio salmonicida Microscopy suggests that bacteria are rampant throughout infected fish, and es- pecially in the blood and kidney of moribund and freshly dead specimens. Pure cultures may be readily recovered from blood and kidney samples on TSA supple- mented with 1.5% (w/v) sodium chloride following incubation at 15°C for up to 5 days (Holm et ai, 1985; Egidius et ai, 1986). Colonies are small, i.e. <lmm in diameter, round, raised, entire and translucent. Inexperienced personnel could easily miss the colonies upon cursory glances at inoculated plates. To some extent, the organism is fragile, and will quickly die at supra-optimum temperatures or by failure to carry out regular subculturing.
Image of page 196
Image of page 197

You've reached the end of your free preview.

Want to read all 594 pages?

  • Spring '20
  • Bacteria, representative, gram-negative bacteria

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors