G. V. Velmurugan
C. Ragendran
M. J. Yabsley
N. J. Thomas
K. B. Beckmen
D. Sinnett
D. Ruid
J. Hart
P.A. Fair
W.E. McFee
V. Shearn-Bochsler
O. C. H. Kwok
L. R. Ferreira
S. Choudhary
E. B. Faria
H. Zhou
T. A. Felix
C. Su
J. P. Dubey
2011
<p><span>Little is known of the genetic diversity of </span><i>Toxoplasma gondii</i><span> circulating in wildlife. In the present study wild animals, from the USA were examined for </span><i>T. gondii</i><span> infection. Tissues of naturally exposed animals were bioassayed in mice for isolation of viable parasites. Viable </span><i>T. gondii</i><span> was isolated from 31 animals including, to our knowledge for the first time, from a bald eagle (</span><i>Haliaeetus leucocephalus</i><span>), five gray wolves (</span><i>Canis lupus</i><span>), a woodrat (</span><i>Neotoma micropus)</i><span>, and five Arctic foxes </span><i>(Alopex lagopus)</i><span>. Additionally, 66 </span><i>T. gondii</i><span> isolates obtained previously, but not genetically characterised, were revived in mice. </span><i>Toxoplasma gondii</i><span> DNA isolated from these 97 samples (31</span><span> </span><span>+</span><span> </span><span>66) was characterised using 11 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, 5′- and 3′-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22–8, c29–2, L358, PK1 and Apico). A total of 95 isolates were successfully genotyped. In addition to clonal Types II, and III, 12 different genotypes were found. These genotype data were combined with 74 </span><i>T. gondii</i><span> isolates previously characterised from wildlife from North America and a composite data set of 169 isolates comprised 22 genotypes, including clonal Types II, III and 20 atypical genotypes. Phylogenetic network analysis showed limited diversity with dominance of a recently designated fourth clonal type (Type 12) in North America, followed by the Type II and III lineages. These three major lineages together accounted for 85% of strains in North America. The Type 12 lineage includes previously identified Type A and X strains from sea otters. This study revealed that the Type 12 lineage accounts for 46.7% (79/169) of isolates and is dominant in wildlife of North America. No clonal Type I strain was identified among these wildlife isolates. These results suggest that </span><i>T. gondii</i><span> strains in wildlife from North America have limited diversity, with the occurrence of only a few major clonal types.</span></p>
application/pdf
10.1016/j.ijpara.2011.06.005
en
Elsevier
Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type
article