Severe coenurosis caused by larvae of Taenia serialis in an olive baboon (Papio anubis) in Benin

Abstract

In March 2017, a captive male juvenile (ca. 6 months old) olive baboon (Papio anubis) was brought to a primate rescue center in Benin with multiple subcutaneous swellings of unknown aetiology. At the general inspection of the body, around 15 partially mobile masses of variable sizes were found in different locations across the body. Following two surgical procedures, several cyst-like structures were removed and placed either in 10% formalin or in absolute ethanol. The cysts had a typical coenurus-like morphology. Genomic DNA was extracted from one cyst using a commercially available kit. The molecular characterization was performed by PCR amplification and sequencing of a region of the nuclear ITS-2 rDNA and a fragment of the mitochondrial 12S rDNA gene, revealing its identity as T. serialis, with 88%-98% similarity to T. serialis isolates from USA, Japan and Germany This study reports a new host for the larval form of T. serialis and confirms the role of primates as intermediate host, highlighting also the risk for human infection. Further genetic studies from multiple geographic isolates are needed to clarify the taxonomic status of this group.

Keywords: Coenurus; Intermediate host; Olive baboon; Taenia serialis.

Graphical abstract

Fig. 1

Clinical presentation of the baboon with the clear presence of swellings in various areas of the body: ventral abdominal and thoracic parts, inner part of forearms, intermandibular region (arrow heads) and dorsal region also.

Fig. 2

Macroscopic appearance of a Taenia serialis cyst during surgery, located in intermuscular tissues. Multiple protoscolices are visible as white spots on the inner surface of the cyst.

Fig. 3

Detail of a protoscolex extracted from a cyst.

Fig. 4

Bootstrap consensus tree inferred from 1000 replicates, using the Maximum Likelihood method. The analysis involved 20 sequences of 12S rDNA gene of cestodes having coenurus type larvae (Taenia serialis and T. multiceps) and one sequence of Echinococcus granulosus, as outgroup. For each sequence, the GenBank Accession number, species, developmental stage, host and geographic origin are provided. A total of 320 positions were included in the dataset. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (1000 replicates) are shown next to the branches.