Test on Parasitic Protozoa in Ectothermic Vertebrates

Question 1: Amastigotes of Sauroleishmania tarentolae occupy both leukocytic and erythroid cells.

A. Ano

B. Ne

Explanation: The diagnosis for Sauroleishmania tarentolae specifies that it is a species in which amastigotes occupy both leukocytic and erythroid cells.

Question 2: Which of the following statements accurately describes the vector competence or transmission mechanisms observed for *Sauroleishmania tarentolae* according to the provided study materials?

A. When *Phlebotomus papatasi* fed on infected geckoes, *S. tarentolae* multiplied in the stomach and then migrated to the thoracic midgut, pharynx, and proboscis.

B. *Sergentomyia antennata* (previously *P. minuta*) could host *S. tarentolae* promastigotes, which were primarily expelled with fecal material, suggesting transmission via ingestion of the sand fly.

C. Infections in *Sergentomyia minuta* were observed to involve promastigotes in malpighian tubules, and in some cases, heavy infections in the midgut and pharynx.

D. Successful experimental transmission of *S. tarentolae* to susceptible lizards has been achieved by the bite of an infected sand fly.

Explanation: *Phlebotomus papatasi* was shown to be infected with *S. tarentolae*, which multiplied in the stomach and moved to the thoracic midgut, pharynx, and proboscis (Adler and Theodor, 1929). *Sergentomyia antennata* (previously *P. minuta*) showed multiplication in the stomach, with promastigotes expelled in fecal material, leading to the belief that transmission occurred by ingestion of the sand fly (Parrot, 1934b, 1935). Natural infections of promastigotes in *Sergentomyia minuta* included malpighian tubules and sometimes heavy midgut and pharynx infections (Killick-Kendrick, 1979). The materials explicitly state, 'There has been no successful experimental transmission of a *Sauroleishmania* species to a susceptible lizard or snake by the bite or ingestion of an infected sand fly,' making the last option incorrect.

Question 3: Sauroplasma infection is known to cause pathogenic effects in its lizard hosts.

A. Ano

B. Ne

Explanation: The study materials state that there is no evidence that infection by Sauroplasma is pathogenic to the lizard host.

Question 4: Which of the following characteristics are part of the diagnosis or description of Serpentoplasma, according to the provided study materials?

A. Infection typically begins in erythroid cells, then spreads to thrombocytes.

B. Division in host cells occurs by budding, binary fission, or possibly merogony, sometimes forming Nuttallia-like tetrads.

C. Intracorpuscular forms are often less than 1 μm in diameter and can show a signet-ring configuration.

D. Pathogenic to the snake host, causing severe anemic changes and other pathological features.

Explanation: According to the study materials, Serpentoplasma infection begins in thrombocytes, not erythroid cells, making option 0 incorrect. The diagnosis states that division occurs by budding, binary fission, or perhaps merogony, sometimes resulting in Nuttallia-like tetrads of nuclei (option 1 is correct). Pienaar's description notes that intracorpuscular forms are tiny spherical or oval bodies (less than 1 μm in diameter) with a typical signet-ring configuration (option 2 is correct). The material states that 'Apart from mild anaemic changes and polychromasia, no other pathological features could be associated with the relatively heavy Serpentoplasma infection,' indicating it is not severely pathogenic, making option 3 incorrect.

Question 5: Trypanosoma boueti is transmitted by mosquitoes to the skink Mabuya striata.

A. Ano

B. Ne

Explanation: The study materials state that observations were made on Trypanosoma boueti in the skink Mabuya striata and the sandfly Sergentomyia bedfordi, implying the sandfly as a vector, not mosquitoes.