Genetic Comparison of Isolates of Listeria Monocytogenes and Listeria Innocua From Different Sources in Australia Publisher



Jalali M¹ ; Richardson B² ; Hazzard A³ Show Affiliations
Source: Journal of Biological Sciences Published:2007

Abstract

Listeria innocua is a closely related nonpathogenic species of Listeria, which has been suggested as an appropriate epidemiological marker for Listeria monocytogenes. Little information is available on the comparative epidemiology and molecular biology of Listeria monocytogenes and Listeria innocua. Using multilocus enzyme electrophoresis to analyse 168 strains collected mainly in poultry production environments, it was shown that Listeria innocua maintains 1.9 alleles per polymorphic loci and a genetic diversity of 0.12 compared with 2.9 alleles and a genetic diversity of 0.48 in Listeria monocytogenes. The number of Electrophortic Type (ET) found in isolates obtained from two poultry production plants in Sydney, Australia also varied, with 54 ETs in 73 isolates of Listeria monocytogenes and 10 ETs in 95 isolates of Listeria innocua. There was one common ET (67%) in Listeria innocua but no common ET in Listeria monocytogenes, where 79% of ETs were represented by a single isolates. Nine isolates obtained from episodic human cases of listeriosis in Australia represented nine different ETs and there was no evidence of a disease specific strain. The marked difference in the level and distribution of genetic variation in Listeria innocua compared to Listeria monocytogenes raises serious doubts as to the validity of using it as a marker surrogate for Listeria monocytogenes. © 2007 Asian Network for Scientific Information.