A link between SIVsm in sooty mangabeys (SM) in wild-living monkeys in Sierra Leone and SIVsm in an American-based SM colony

We have developed a noninvasive method for SIVsm virion RNA detection in feces of captive sooty mangabeys (SMs) ( Cercocebus atys). Employing this method to investigate the natural history of SIVsm in endangered SMs is useful for understanding the diversity and evolution of SIVsm and HIV-2. The fecal samples of 61 wild-living SMs and 14 chimpanzees ( Pan troglodytes verus) were studied. Samples were collected in rural Sierra Leone in 1993. One SM sample tested positive by reverse transcriptase-PCR. No viral sequence was detected in the feces of 14 chimpanzees. Phylogenetic analysis of the env sequence obtained from SM#13 showed that it clustered within the SIVsm lineage that includes SIVsmH4, B670, and PBj, confirming a direct connection between SIVsm from West Africa and an American-based colony of SM. The virus, designated as SIVsmSL93g, supports a link between the SIVB670/SIVsmH4/SIVPbj lineage and SMs living in Northern Sierra Leone in 1993. The discovery of this strain in a wild-living SM also indicates that noninvasive methods can be used for SIV detection from monkey feces collected in the field.