Antibiotic resistance and molecular typing of Listeria monocytogenes from foods in Shandong province from 2009 to 2010

Abstract

To know the antibiotic resistance and molecular characteristics of Listeria monocytogenes in Shandong province and to study the relationship between antibiotic resistance phenotypes and genome types. From 2009 to 2010, a total of 80 Listeria monocytogenes isolates were collected from raw meat, cooked meat, aquatic products and other foods in 6 cities of Shandong province. The antibiotic susceptibility was measured by broth microdilution method, PFGE was performed for molecular typing and the relationship between antimicrobial resistance and PFGE patterns was analyzed. 16.25% (13/80) of the isolates were drug-resistant. Imipenem resistance was the most prevalent (12.50%, 10/80), followed by tetracycline and doxycycline (3.75%, 3/80 and 2.50%, 2/80). A total of the 80 isolates were subtyped into 9 antibiotic resistance patterns and 34 PFGE types which were largely dominated by the type 17 and 29. Antibiotic resistance pattern A corresponded to 79.41% (27/34) of PFGE types. The antibiotic resistance of Listeria monocytogenes in Shandong province is serious from 2009 to 2010 and there is no correlation between PFGE types and antibiotic resistance patterns.