| Autor: |
Takai, Shinji, Chaffin, M. Keith, Cohen, Noah D., Hara, Michiyo, Nakamura, Mutsu, Kakuda, Tsutomu, Sasaki, Yukako, Tsubaki, Shiro, Martens, Ronald J. |
| Zdroj: |
Journal of Veterinary Diagnostic Investigation; November 2001, Vol. 13 Issue: 6 p489-494, 6p |
| Abstrakt: |
Rhodococcus equiisolates (462) obtained from 64 soil samples collected on 5 R. equi-endemic horse-breeding farms and isolates from 100 infected foals in Texas were examined to determine the prevalence and genotypic diversity of virulence-associated plasmids. Isolates were tested for the presence of 15–17-kDa virulence-associated protein antigens (VapA) by immunoblotting and virulence-associated plasmids by PCR. Plasmid DNAs were isolated and analyzed by digestion with restriction endonucleases for estimation of size and comparison of polymorphisims. Rhodococcus equiwere isolated from soil of all 5 farms; however, virulent R. equiwere only isolated from 3 of the 5 farms and represented 18.8% (87 of 462) of total isolates. Of the 87 virulent soil isolates, 56 (64.5%) contained an 85-kb type I plasmid, 23 (26.4%) an 87-kb type I plasmid, 7 (8%) a newly defined 85-kb type III plasmid (Tx 43), and 1 (1.1%) a newly defined 85-kb type IV plasmid (Tx 47). Of the 100 isolates from infected foals, 96 were virulent. Of the 96 virulent isolates, 51 (53.1%) contained an 85-kb type I plasmid, 39 (40.6%) an 87-kb type I plasmid, 4 (4.2%) an 85-kb type III plasmid (Tx 43), and 2 (2.1%) an 85-kb type IV plasmid (Tx 47). There are at least 4 different R. equivirulence-associated plasmids in Texas, 2 of which have not previously been described. Based upon virulence plasmid typing, there is geographic diversity among isolates of R. equifrom clinical and environmental samples on horse-breeding farms in Texas. There is not a strong correlation between the presence of virulent R. equiin farm soils and the R. equidisease status of those farms. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
