Quaglio + Marcer Exam

Question 1

Cryptocaryon irritans is

a. an ectoparasite of marine fish
b. a virus transmitted by contaminated water
c. an endoparasite of cetaceans
d. an endoparasite of freshwater fish

Answer 1

a. an ectoparasite of marine fish

Question 2

For routine histological analyses, the samples should be

a. fresh and immediately fixed in formalin
b. frozen and later fixed in formalin
c. kept at room temperature
d. kept in absolute ethanol

Answer 2

a. fresh and immediately fixed in formalin

Question 3

For copromicroscopic exam you need to collect fresh feces and store them in a

a. sterile container at room temperature
b. sterile container with the addition of physiological solution at room temperature
c. sterile vacuum container at −80°C
d. clean container at +4°C

Answer 3

d. clean container at +4°C

Question 4

Clinical signs of columnaris disease are represented by

a. steatosis, swollen and hypertrophic kidney
b. severe erosive lesions on gills, up to diffuse gill necrosis and deep ulcers
c. swollen hypertrophic kidney
d. myocarditis

Answer 4

b. severe erosive lesions on gills, up to diffuse gill necrosis and deep ulcers

Question 5

Fill in the following form for vibriosis

1. Main species of Vibrio involved

Answer 5

• Vibrio anguillarum
• Vibrio salmonicida
• Vibrio harveyi

Question 6

Fill in the following form for vibriosis

2. Sensitive fish hosts

Answer 6

• Salmonidae
• Marine, euryhaline, and freshwater fish
• Wide host range (cosmopolitan distribution)

Question 7

Fill in the following form for vibriosis

3. Main gross lesions

Answer 7

Question 8

Fill in the following form for vibriosis

4. Diagnosis (methods)

Answer 8

• Bacteriology: Isolation and identification by culturing.
• PCR: Polymerase chain reaction for genetic detection.

Question 9

Fill in the following form for vibriosis

5. Prophylaxis and control

Answer 9

• Immersion treatment (antibiotics)
• Vaccination (injection gun)
• Biosecurity measures (hygiene, husbandry, and welfare)

Question 10

Nodular Gill Disease

a) Bacteria
b) Virus
c) mycotic
d) ?

Answer 10

d) Amoebae –> protozoan eukaryotic parasite

Question 11

Sturgeon skeletal deformities

a) viral
b) trauma
c) gametic

Answer 11

b) trauma

Question 12

Whirling Disease is

• caused by?
• found in ?

Answer 12

1. Myxobolus (Myxosoma) cerebralis = Parasite
2. Salmonids (salmon + trout)

Question 13

Whirling Disease infects?

Answer 13

• cartilage
• eventually nervous tissue

Question 14

What are clinical signs of Whirling Disease?

Answer 14

• fish “whirl” forward in corkscrew-like, circular swimming pattern
• black tail
• spinal deformities
• eventually other deformities in anterior part of fish

Question 15

Columnari Disease: clinical signs?

Answer 15

caused by bacterial pathogen Flavobacterium columnare

Question 16

What is Toxoplasmosis?

Answer 16

Toxoplasma gondii (protozoan Parasite)

Question 17

Lifecycle of Toxoplasma gondii

Answer 17

1. Definitive Host: Felids

• here Bradyzoites mature and, reach adult stage and sexual maturity
• here they release oocytes that are entering environment through feces

2. Intermediate hosts: all warm-blooded animals (marine and terrestrial)

Question 18

What are the three infective stages of T. gondii?

Answer 18

1. Sporozoites

• Shed in cat feces, highly resistant in the environment (viable for 24 months in marine water)
• oocytes first need to sporulate to become infectious (1-5 days)
• found in environment

2. Tachyzoites

• found in intermediate hosts
• they penetrate intestinal wall if I.H. and enter the bloodstream
• allows to reach tissue: eyes, muscle, CNS
• tachyzoites can be transmitted vertically (breastfeeding/mild + placenta/blood)
• cause infections in host
• differentiate and develop into:

3. Bradyzoites

• 3rd infectious stage
• found in muscle tissue where they form tissue cysts
• these are eaten by D.H. (felid)

Question 19

What are symptoms of T. gondii in marine mammals?

Answer 19

• Severe (non-suppurative) meningoencephalitis.
• High risk for immunocompromised individuals (e.g., due to morbillivirus or PCB exposure).
• Atypical pathological effects, as observed in monk seals
• abortions evtl. due to vertikal transmission

Question 20

Acute phase of T. gondii?

Answer 20

asexual reproduction in blood of I.H.

Question 21

Sexual reproduction of T. gondii?

Answer 21

in intestinal cells of D.H.

Question 22

How can marine mammals be infected?

Answer 22

• Ingestion of oocysts washed into marine environments from land via coastal runoff.
• mollusks and plants can act as mechanical vectors (= no support of T. gondii development, but transport-function)
• marine mammals can eat contaminated fish or invertebrates

Question 23

Transmission of T. gondii

Answer 23

• Horizontal: Ingestion of oocyst-contaminated food or water.
• Vertical: Transplacental transmission documented in marine mammals like bottlenose dolphins and monk seals​

Question 24

Diagnosis of T. gondii?

Answer 24

• Histology: Detection of cysts and lesions in formalin-fixed tissues.
• Immunohistochemistry: To confirm presence in tissues.
• PCR: Analysis of CNS, heart, and other tissues (fresh, refrigerated, or frozen).
• Serology: Epidemiological studies using serum​

Question 25

What is a parasite?

Answer 25

A parasite is an organism living in (endoparasite) or on (ectoparasite) an other organism (the host). It feeds and acquires nutrients or benefits from the host and brings pathogenic effects. Their relationship is "with damage" for the host.

Question 26

What is a host?

Answer 26

The organism the parasite lives in or on

Question 27

Mention or explain 4 kinds of relationships between organisms.

Answer 27

- There is relationships with or without damage. - without damage: Mutualism (+/+) and Commensalism (+/0) with damage: "Predatorism" (+/-) and Parasitism (+/-), where parasite benefits from host and thereby harms the host

Question 28

What are the main forms of Parasitism?

Answer 28

- **obligate parasites:** the parasite depends on host (permanently, periodically, temporary) - **facultative:** parasite can also survive without the host - **accidental:** e.g. Anisakis is an accidental parasite for humans, when they eat uncooked fish that contained larvae

Question 29

What is the difference between endoparasitism and ectoparasitism?

Answer 29

- **Endoparasitism** is when the parasite lives in the host’s body - **Ectoparasitism** is when the parasite lives on the skin or the extremal body of the host (e.g. carapace)

Question 30

What is - Polyparasitism - Pseudoparasitism

Answer 30

- **Polyparasitism** when there is more than one parasite cohabiting a host - **Pseudoparasitism** when a parasite of *another* species is accidentally ingested by a host --> parasite doesn't take roots in the host

Question 31

What are the main categories of parasites based on their Life cycle?

Answer 31

- **monoxenous** = direct LC (only D.H.) with or without a free phase in the external environment - **eteroxenous** = indirect LC (with 1 or >1 I.H.)

Question 32

What are the main categories of host and explain them?

Answer 32

- **Intermediate host:** They are required for the completion of a parasite’s life cycle. - **Definitive host:** They are essential to the completion of an organism’s life cycle and usually hosts the adult stage of the organism to reach sexual maturity. - **Paratenic host:** They are not necessarily for the life cycle of the organism but can hist them for a long period of time without them undergoing any significant development

Question 33

What are the determinants of a disease?

Answer 33

- Etiological agents - Host - Environment

Question 34

Under each determinant of a disease, state or describe the factors.

Answer 34

- Etiological agents can also be termed as the **primary factors** and they include endo/ecto parasites, the type of life cycle it undergoes, its virulence and the organs they target. - Host also known as the **internal factors** include the age, the species, its immunocompetence and nutritional status of the host. - Environment also known as the **external factors.** This ranges from the environmental conditions, climate change, temperature, and other physicochemical parameters.

Question 35

Mention some epibionts of sea turtles that are linked to their immune system alteration and other diseases.

Answer 35

- Barnacles - Amphipods - Polychaetes - Molluscs

Question 36

Write short notes on Leeches

Answer 36

- primary host: loggerhead sea turtle *(Caretta caretta)* - they cause: 1. severe skin lesions 2. deep cutaneous erosions 3. severe eye injuries 4. death (in severe cases) - they are vectors for transmitting many infectious diseases - direct LC - stay as permanent damaging parasite

Question 37

Write short notes on *Sulcascaris sulcata*

Answer 37

- nematodes - D.H.: Loggerhead Seaturtles, green turtles, Kemp's Ridley turtles (in stomach) - Distribution in warm marine waters (Pacific, Atlantic, Caribbean, Mediterranean) - indirect LC with benthonic I.H.: mollusks and gastropods - they causee 1. ulcers 2. gastritis 3. lesions (severity increases with parasite load)

Question 38

Write short notes on Blood flukes (spirorchiids) in sea turtles

Answer 38

- endoparasite - flatworms - infect marine and freshwater turtles - adult worms present in blood vessels - eggs migrate through host's body - indirect LC - D.H.: neritic species (feeding in shallow waters) - I.H.: **gastropods and annelids** - they cause: 1. lesions 2. granulomatous inflammation 3. thrombosis