Plasmid Profiles and Prevalence of Intermediately Virulent Rhodococcus equi from Pigs in Nakhonpathom Province, Thailand: Identification of a New Variant of the 70-kb Virulence Plasmid, Type 18.
The prevalence of intermediately virulent Rhodococcus equi isolates from pig submaxillary lymph nodes from four slaughterhouses in Nakhonpathom province, Thailand, was investigated. The isolates were tested for the presence of virulence plasmids and the 20-kDa virulence-associated protein antigen (VapB) gene by PCR. Of the 734 submaxillary lymph nodes tested, 19 (2.6%) produced positive cultures of R. equi. All 19 isolates were positive for the VapB gene and contained virulence plasmids that were identified as type 1 (six isolates), type 6 (two isolates), type 7 (one isolate), type 16 (two isolates), and a new variant (eight isolates). Based on the restriction digestion patterns of the plasmid DNAs, we tentatively designated the variant as type 18. Investigation of the prevalence and plasmid profiles of VapB-positive R. equi in pigs should be extended throughout Thailand to evaluate potential sources of zoonotic infections.
Poolkhet
Chaithep
C
Faculty of Veterinary Medicine, Kasetsart University, Nakhonpathom 73140, Thailand.
Chumsing
Suksun
S
Wajjwalku
Worawidh
W
Minato
Chihiro
C
Otsu
Yukiko
Y
Takai
Shinji
S
J Clin Microbiol. 1994 Feb;32(2):457-60
8150957
J Infect Chemother. 2005 Feb;11(1):37-40
15729486
J Infect Dis. 2003 Dec 1;188(11):1717-23
14639543
J Clin Microbiol. 1979 May;9(5):640-2
479362
J Clin Microbiol. 1991 Mar;29(3):439-43
2037660
J Clin Microbiol. 1996 Apr;34(4):1034-7
8815079
J Clin Microbiol. 1991 Dec;29(12):2696-700
1757535
J Infect Dis. 1995 Nov;172(5):1306-11
7594668
Vet Microbiol. 2002 Sep 24;88(4):377-84
12220812
J Bacteriol. 2008 Sep;190(17):5797-805
18606735
FEMS Immunol Med Microbiol. 1998 Dec;22(4):329-33
9879924
Vet Microbiol. 1997 Jun 16;56(3-4):167-76
9226831
Am J Trop Med Hyg. 2002 Jan;66(1):52-5
12135268
Vet Microbiol. 2007 Mar 10;120(3-4):352-7
17126501
J Clin Microbiol. 2005 Mar;43(3):1246-50
15750091
Comp Immunol Microbiol Infect Dis. 2005 Jan;28(1):53-61
15563953
Nucleic Acids Res. 1979 Nov 24;7(6):1513-23
388356
Vet Microbiol. 2008 Oct 15;131(3-4):318-23
18499361