Questions and Answers
What is the typical incubation temperature for P.anguilliseptica growth on nutrient agar?
25°C
Which of the following tests is P.anguilliseptica negative for?
O–F test
What is the common feature of epizootiology in Japanese and European eels infected with P.anguilliseptica?
Low water temperatures in spring time
Which of the following organs is NOT affected by focal haemorrhagic necrosis in P.anguilliseptica infection?
Signup and view all the answers
What is the primary requirement for successful antibiotic treatment of P.anguilliseptica infection?
Signup and view all the answers
What has the most significant effect on mortalities as mentioned?
Signup and view all the answers
What is the diameter size range of Chlamydiaceae microorganisms in their developmental stages?
Signup and view all the answers
What is the stage called when the Chlamydiaceae microorganism becomes non-infectious within the host cell?
Signup and view all the answers
Which condition is associated with epitheliocystis, and what is a distinct feature of this disease?
Signup and view all the answers
What is the main difficulty in definitively diagnosing epitheliocystis?
Signup and view all the answers
Study Notes
P. anguilliseptica Characteristics
- Forms 1 mm diameter colonies on nutrient agar after 3-4 days of incubation at 25°C
- Growth can be enhanced by adding 10% horse blood to the medium
- Catalase and oxidase-positive
- Does not produce acid from glucose and gives no reaction in the O-F test
- Hydrolyses gelatine but is arginine-negative
Sekitenbyo (Red Spot Disease)
- P. anguilliseptica is the causal agent of Sekitenbyo
- A major disease of Japanese eel
- Also affects European eel, but less susceptible
- Typically occurs in spring time with low water temperatures
- Characterized by darkening, inappetance, and one or more 'red spots' (deep haemorrhagic ulcers)
Clinical Pathology
- Features of acute septicaemia: petechial haemorrhages, swollen bright red spleen
- Focal haemorrhagic necrosis in liver, heart, and spleen
- Necrotic haemopoietic tissue in spleen and kidney
- Bacterial colonies within lesions
- Leucocytosis with predominance of pigment-bearing leucocytes in blood smears
Treatment
- Antibiotic treatment has a role, but environmental stress must be removed
- Raising water temperature to >26°C has a significant effect on mortalities
Chlamydiaceae
- Gram-negative coccoid microorganisms (0.2-1.5 µm in diameter)
- Obligatory intracellular parasites
- Infectious particle is the elementary body, which enlarges to become the non-infectious initial body
- Divides by fission and forms mature, infectious, elementary bodies
Epitheliocystis
- Believed to be caused by Chlamydial organisms
- Benign or proliferative condition of the gill and skin epithelium
- Characterized by white miliary swellings on skin or gills (up to 0.8 mm in diameter)
- Histopathological picture: distension of individual epithelial cells, strongly basophilic, with large numbers of coccoid or coccobacillary bodies
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
