Résumé
Simian immunodeficiency virus (SIV) infects many primate species. Chimpanzees (Pan troglodytes) can develop an immune disease similar to human acquired immunodeficiency syndrome (AIDS). Immunosuppressed patients often suffer from opportunistic diseases such as microsporidiosis and cryptosporidiosis. We report on the occurrence of infections with microsporidia and Cryptosporidium spp. in wild-living chimpanzees, gorillas (Gorilla gorilla gorilla), bonobos (Pan paniscus), and four monkey species from the Cercopithecinae subfamily (Cercocebus agilis, Cercopithecus cephus, Cercopithecus nictitans, and Lophocebus albigena) and assess whether these infections may be good indicators of SIV-related immunosuppression. We analyzed 399 fecal samples collected in Cameroon and Democratic Republic of Congo for the presence of cross-reactive HIV antibodies using a line immunoassay (INNO-LIAA (R)). We amplified via polymerase chain reaction (PCR) a 200-500 bp DNA fragment for the genus Encephalitozoon and the genus Enterocytozoon respectively (microsporidia), and an 820 bp DNA fragment of various Cryptosporidium species. Twenty-nine percent (45/155) of the chimpanzees samples analyzed were SIV+, whereas samples from the other primate species were SIV-. Phylogenetic analyses showed that 11 fecal samples [one SIV+, four SIV- chimpanzees, three gorillas, a bonobo, an agile mangabey (Cercocebus agilis), and a moustached monkey (Cercopithecus cephus)] are infected with microsporidia. DNA sequences of amplicons derived from eight fecal samples clustered together with Encephalitozoon hellem and three branched close to E. intestinalis. We also amplified Cryptosporidium spp. in two SIV+ chimpanzee samples and in two gorilla samples. We found no significant association between SIV infection status in chimpanzees and the presence of microsporidia or Cryptosporidium, suggesting that detection of microsporidia and Cryptosporidium is not a reliable marker for immunosuppressive status in SIV-infected primates.