Molecular and serological evidence of Pneumocystis circulation in a social organization of healthy macaques (Macaca fascicularis)

Abstract

Simian populations represent valuable models for understanding the epidemiology of human pneumocystosis. The present study aims to describe the circulation ofPneumocystisorganisms within a social organization of healthy crab-eating macaques (Macaca fascicularis) living in a natural setting in France. Animals were followed for up to 2 years. Deep nasal swab and blood samples were collected monthly from each animal under general anaesthesia. Environmental air was sampled for a 1 week period every month in the park where the macaques dwelt.PneumocystisDNA was detected by nested-PCR of mitochondrial large subunit rRNA (mtLSU) gene in nasal swab and air samples. Anti-PneumocystisIgG antibodies were detected in serum samples by indirect immuno-fluorescence assay.PneumocystisDNA was detected in 168 of 500 swab samples examined (33·6 %). The number of macaques with detectablePneumocystisDNA was highly variable from one month to another. Positive detection ofPneumocystisDNA was not related to the detection of serum anti-Pneumocystisantibody. During the second year of the study,PneumocystisDNA was amplified more frequently from unweaned macaques than from adults or subadults. The mtLSU sequence showed marked polymorphism with eightPneumocystissequence types representing two distinct groups. On the whole, a constant and intensive circulation ofPneumocystisorganisms within the community was observed. However, the implication of the various members of the colony was probably different and several levels of colonization byPneumocystismay occur in immunocompetent macaques.