1.Global genetic diversity of Spirometra tapeworms
Hong, X. ; Liu, S.N. ; Xu, F.F. ; Han, L.L. ; Jiang, P. ; Wang, Z.Q. ; Cui, J. ; Zhang, X.
Tropical Biomedicine 2020;37(No.1):237-250
Spirometra larvae are etiological agents of human sparganosis. However, the systematics of spirometrid cestodes has long been controversial. In order to determine the current knowledge on the evolution and genetic structure of Spirometra, an exhaustive population diversity analysis of spirometrid cestodes using the mitochondrial gene: cytochrome c oxidase subunit 1 (cox1) was performed. All publicly available cox1 sequences available in the GenBank and 127 new sequencing genes from China were used as the dataset. The haplotype identify, network, genetic differentiation and phylogenetic analysis were conducted successively. A total of 488 sequences from 20 host species, representing four spirometrid tapeworms (S. decipiens, S. ranarum, S. erinaceieuropaei and Sparganum proliferum) and several unclassified American and African isolates from 113 geographical locations in 17 countries, identified 45 haplotypes. The genetic analysis revealed that there are four clades of spirometrid cestodes: Clade 1 (Brazil + USA) and Clade 2 (Argentina + Venezuela) included isolates from America, Clade 3 contained African isolates and one Korean sample, and the remainders from Asia and Australia belonged to Clade 4; unclassified Spirometra from America and Africa should be considered the separate species within the genus; and the taxonomy of two Korea isolates (S. erinaceieuropaei KJ599680 and S. decipiens KJ599679) was still ambiguous and needs to be further identified. In addition, the demographical analyses supported population expansion for the total spirometrid population. In summary, four lineages were found in the spirometrid tapeworm, and further investigation with deeper sampling is needed to elucidate the population structure.
2.Epidemiological investigation and risk factors of Peste des petitis ruminants (PPR) in yaks (Bos grunniens) and cattle in five regions of China
Li, X.H. ; Li, K. ; Zhang, H. ; Gan, P. ; Luo, H.Q ; Han, Z.Q ; Mehmood, K. ; Shahzad, M.
Tropical Biomedicine 2018;35(3):736-743
To investigate the prevalence of Peste des petitis ruminants in yaks and cattle in
poorly studied areas of China. A total of 1202 and 560 blood samples were collected from
yaks and cattle, respectively and processed using a commercial ELISA kit. Multivariable
logistic regression model was piloted to find the variables, potentially associated with exposure
of PPR infection in yaks and cattle. Results indicated that the overall prevalence of PPR in
yaks was 11.2%. A total 66 (11.8%) out of 560 were examined out to be positive to PPR in
cattle in Jiangxi province. According to conditional stepwise logistic regression, region, age
and gender were found to be the more influencing risk factors in yaks, while region and age
were found to be the potential risk factors in cattle. The current results reported the prevalence
and associated risk factors of PPR in bovine for the first time in China.