Using MLVA to type strains of Salmonella Typhimurium in New South Wales

Phage typing has been the traditional strain typing (or .fingerprinting.) method used in Australia for surveillance of common salmonella serovars (such as Salmonella Typhimurium) and outbreak investigations. The need for more accessible, discriminatory and objective methods has been recognised but, until now, none has been widely accepted. Recently, the molecular typing method, known as MLVA (multilocus variable number tandem repeat analysis), has been applied to several Salmonella serovars and promises to provide faster strain typing and cluster identification than phage typing, with comparable or better sensitivity. The present article is intended as a short primer on MLVA typing, which has recently been introduced into routine use at the New South Wales Enteric Reference Laboratory at the Centre for Infectious Diseases and Microbiology, Institute of Clinical Pathology and Medical Research, Westmead.