Pulsed-field gel electrophoresis (PFGE)를 이용한 Listeria monocytogenes의 molecular typing

A total of 1,354 samples was collected from bovine and porcine carcass from January 2005 to December 2006 in a slaughter house. Twenty five strains(1.8%) of Listeria monocytogenes were isolated from 1,354 samples using selective media. Ten(1.4%) L monocytogenes were isolated from the 677 of bovine carcasses, and 15(2.2%) were isolated from the 677 of porcine carcasses. Among 15 L mono-cytogenes from porcine, 11 siolates were serovars 1/2c, followed by 1/2b (3 strains, 20.0%) and 1/2a(1 strain) Out of 10 bovine samples, positive cases in 1/2a were 9 strains (90.0%), 1/2b were 1 strains(10.0%). PCR primers were selected to amplify a 520-base pair(bp) DNA fragment from the listeolysin O gene (hlyA) of L mono-cytogenes. A 520-bp product was detected in PCR with DNA from L monocytogenes, but not from the other Listeria species tested. A total of 25 L monocytogenes strains were analysed by PFGE after digestion with Apa I. PFGE analysis of genomic DNA showed the $14{\sim}18$ fragments ranging in size from 30 to 550 kb, resulting in 14 patterns.