Effectiveness of BOX-PCR in Differentiating Genetic Relatedness amongSalmonella entericaSerotype 4,[5],12:i:- Isolates from Hospitalized Patients and Minced Pork Samples in Northern Thailand

Abstract

Salmonella entericaSerotype 4,[5],12:i:-, a monophasic variant ofS. Typhimurium, with high virulence and multidrug resistance is distributed globally causing pathogenicity to both humans and domesticated animals. BOX-A1R-based repetitive extragenic palindromic-PCR (BOX)-PCR proved to be superior to three other repetitive element-based PCR typing methods, namely, enterobacterial repetitive intergenic consensus (ERIC)-, poly-trinucleotide (GTG)5-, and repetitive extragenic palindromic (REP)-PCR (carried out under a single optimized amplification condition), in differentiating genetic relatedness amongS. 4,[5],12:i:- isolates from feces of hospitalized patients (n=12) and isolates from minced pork samples ofS. 4,[5],12:i:- (n=6),S. Typhimurium (n=6), andSalmonellaSerogroup B (n=4) collected from different regions of northern Thailand. Construction of phylogenetic trees from amplicon size patterns allowed allocation ofSalmonellaisolates into clusters of similar genetic relatedness, with BOX-PCR generating more unique clusters for each serotype than the other three typing methods. BOX-, (GTG)5-, and REP-PCR indicated significant genetic relatedness betweenS. 4,[5],12:i:- isolates 1 and 9 from hospitalized patients andS. 4,[5],12:i:- isolate en 29 from minced pork, suggesting a possible route of transmission. Thus, BOX-PCR provides a suitable molecular typing method for discriminating genetic relatedness amongSalmonellaspp. of the same and different serotypes and should be suitable for application in typing and tracking route of transmission inSalmonellaoutbreaks.