Genotyping of Toxoplasma gondii in a lethal toxoplasmosis outbreak affecting captive howler monkeys (Alouatta sp.)

Abstract

Background Toxoplasmosis is a zoonotic disease that affects humans and warm‐blooded animals. This study describes an outbreak of toxoplasmosis in howler monkeys (Alouatta sp.) and survival of capuchins (Sapajus apella), under the same environmental conditions. Methods Howler monkeys were submitted to post‐mortem examination. Tissue samples were processed to histopathology and immunohistochemistry to detect lesions and tachyzoites of Toxoplasma gondii. Tissue samples were also frozen and submitted to PCR and genotyping of T. gondii. Results Typical lesions were observed in several organs including the liver, lymph node, and brain, with intralesional cysts and tachyzoites of T. gondii demonstrated by immunohistochemistry. T. gondii genomic sequences were amplified by PCR, and genotyping characterized the same T. gondii clone in all howler monkeys. Conclusions Our results support the notion that some species of neotropical primates are highly susceptible to toxoplasmosis and the hypothesis that capuchins (S. apella) may be resistant.

Molecular detection of Toxoplasma gondii and Neospora caninum in neotropical primates

“…There are marked differences in the natural resistance against T. gondii in this group of animals, due to behavioral, ecological, physiological, and evolutionary differences between the species; therefore, mortality rates vary from 0% to 100%, depending on the severity. 2,4,13 When infected with T. gondii, a primate may present neurological clinical signs such as motor incoordination due to encephalitis caused by the installation of protozoan cysts in the central nervous system, 11 which is the same clinical sign reported in the animals in this study.…”

“…There are marked differences in the natural resistance against T . gondii in this group of animals, due to behavioral, ecological, physiological, and evolutionary differences between the species; therefore, mortality rates vary from 0% to 100%, depending on the severity 2,4,13 …”

“…caninum ), which is responsible for neosporosis are the etiological agents of multisystemic diseases, especially in neurological and reproductive systems. Neotropical primates are intermediate hosts of these pathogens and commonly contribute to acute and potentially fatal clinical outcomes 3,4 …”

“…primates are intermediate hosts of these pathogens and commonly contribute to acute and potentially fatal clinical outcomes. 3,4 In Brazil, studies on the health profile of these animals are scarce because of the limited resources to adequately detail the great diversity of the country's fauna. Thus, molecular tests, especially polymerase chain reaction (PCR), which is highly sensitive and specific when compared to other methods, aid in providing the correct diagnosis of pathological agents that jeopardize the survival of freeliving and captive neotropical primates.…”

Parasites of Free-Ranging and Captive American Primates: A Systematic Review

“…Some studies on Blastocystis assessed the genetic variability and host specificity, reporting different subtypes (ST1-ST5, ST8) [42,61,116]. Studies on Trypanosoma cruzi identified the genetic lineages of the parasite (TcI-TcIII, TcV, TcVI) [64,90] as well as types of Toxoplasma gondii (Type I, Type II, non-archetypal) [39,100]. Molecular approaches were less frequent in studies of nematodes: Trypanoxyuris sp., Dipetalonema sp., Mansonella sp., Brugia sp., Pterygodermatites sp.…”