Infect Chemother.  2004 Dec;36(6):335-340.

Distribution and Study on Single Nucleotide Polymorphism (SNP) of spvR Gene in Korean Isolates of Salmonella

• Kwon HJ
• Park KY
• Park JY
• Park YH
• Kim SJ
• Yoo HS

Abstract

BACKGROUND: The Salmonella virulence plasmid (spv) genes (spvR, A, B, C and D) on the large virulence plasmids of pathogenic Salmonella serotypes can replace the virulence of the whole plasmid. Recently, virulence plasmid-negative pathogenic Salmonella isolates were isolated. However, positive rates of spv genes among Korean Salmonella serotypes have been obscure. spv genes are conserved in compared to other virulence genes but there are single nucleotide polymorphisms (SNPs) conserved in only certain serotype. Such SNPs are useful for differentiation and understanding evolution of certain serotypes.
MATERIALS AND METHODS
Salmonella serotypes isolated from live stocks [Salmonella typhimurium (ST, 26), S. enteritidis (SE, 10), S. gallinarum (SG, 40) and S. pullorum (SP, 53)] were used for colony-PCR. A primer set covering single nucleotide polymorphism (SNP) at 625th nucleotide of spvR was designed. The nucleotide sequences of amplicons were determined by cyclic sequencing method and RFLP was performed by using MseI.
RESULTS
All isolates of SE, SG and SP, including four plasmid-negative isolates, showed specific amplicons but not all of ST (19/26, 73%) were positive to spvR. Based on the nucleotide sequence of 625th nucleotide and PCR-RFLP, SE, SG and SP [A(625)] and ST [G(625)] could be differentiated.
CONCLUSION
spvR can be used as a molecular marker to detect virulent SE, SG, SP and the SNP may be useful for differentiation of SE, SG, SP and ST. According to the SNP study SE may be evolutionarily closer to SG and SP than ST.

Keyword

Salmonella; spvR; Virulence plasmid; Single nucleotide polymorphism (SNP); Colony-PCR

MeSH Terms

Base Sequence
Plasmids
Polymorphism, Restriction Fragment Length
Polymorphism, Single Nucleotide*
Salmonella*
Virulence