Multiple diverse circoviruses infect farm animals and are commonly found in human and chimpanzee feces.
Circoviruses are known to infect birds and pigs and can cause a wide range of severe symptoms with significant economic impact. Using viral metagenomics, we identified circovirus-like DNA sequences and characterized 15 circular viral DNA genomes in stool samples from humans in Pakistan, Nigeria, Tunisia, and the United States and from wild chimpanzees. Distinct genomic features and phylogenetic analysis indicate that some viral genomes were part of a previously unrecognized genus in the Circoviridae family we tentatively named "Cyclovirus" whose genetic diversity is comparable to that of all the known species in the Circovirus genus. Circoviridae detection in the stools of U.S. adults was limited to porcine circoviruses which were also found in most U.S. pork products. To determine whether the divergent cycloviruses found in non-U.S. human stools were of dietary origin, we genetically compared them to the cycloviruses in muscle tissue samples of commonly eaten farm animals in Pakistan and Nigeria. Limited genetic overlap between cycloviruses in human stool samples and local cow, goat, sheep, camel, and chicken meat samples indicated that the majority of the 25 Cyclovirus species identified might be human viruses. We show that the genetic diversity of small circular DNA viral genomes in various mammals, including humans, is significantly larger than previously recognized, and frequent exposure through meat consumption and contact with animal or human feces provides ample opportunities for cyclovirus transmission. Determining the role of cycloviruses, found in 7 to 17% of non-U.S. human stools and 3 to 55% of non-U.S. meat samples tested, in both human and animal diseases is now facilitated by knowledge of their genomes.
Li
Linlin
L
Blood Systems Research Institute, 270 Masonic Ave., San Francisco, CA 94118, USA.
Kapoor
Amit
A
Slikas
Beth
B
Bamidele
Oderinde Soji
OS
Wang
Chunlin
C
Shaukat
Shahzad
S
Masroor
Muhammad Alam
MA
Wilson
Michael L
ML
Ndjango
Jean-Bosco N
JB
Peeters
Martine
M
Gross-Camp
Nicole D
ND
Muller
Martin N
MN
Hahn
Beatrice H
BH
Wolfe
Nathan D
ND
Triki
Hinda
H
Bartkus
Joanne
J
Zaidi
Sohail Zahoor
SZ
Delwart
Eric
E
D000328:Adult; D000818:Animals; D000829:Animals, Domestic / Q000821:virology; D001483:Base Sequence; D002648:Child; D018136:Circoviridae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D018173:Circoviridae Infections / Q000662:veterinary / Q000821:virology; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D005243:Feces / Q000821:virology; D005814:Genes, Viral; D014644:Genetic Variation; D006801:Humans; D008460:Meat / Q000821:virology; D008969:Molecular Sequence Data; D002679:Pan troglodytes / Q000821:virology; D010802:Phylogeny; D034421:Sus scrofa / Q000821:virology
D017931:DNA Primers; D004279:DNA, Viral