The propagation of Vi-phage I1 on ‘degraded Vi strains ’ of Salmonella typhi did not yield phage preparations bearing any trace of the specificity of the original Vi type from which the degraded strains had sprung. Ten different standard Vi-typing phages were grown on a selection of degraded Vi strains. The phages could be separated into two groups: six underwent a change which appeared to be a...

A typing procedure for methicillin-resistant Staphylococcus aureus (MRSA) based on the polymerase chain reaction (PCR) amplification of both mecA sequences and variable DNA sequences as present in the prokaryotic genome has been developed. Two primers based on the sequences of DNA repeats as discovered in gram-negative members of the family Enterobacteriaceae allow detection of variable regions...

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 (m...

Panton-Valentine leukocidin (PVL, encoded by lukSF-PV genes), a bi-component and pore-forming toxin, is carried by different staphylococcal bacteriophages. The prevalence of PVL in Staphylococcus aureus has been reported around the globe. However, the data on PVL-encoding phage types, lukSF-PV gene variation and chromosomal phage insertion sites for PVL-positive S. aureus are limited, especiall...

For epidemiologic investigations, the primary subdivision of Salmonella Typhi is vi-phage typing; 106 Vi-phage types are defined. For multidrug-resistant strains the most common types have been M1 (Pakistan) and E1 (India, Pakistan, Bangladesh, and the Arabian Gulf); a strain untypable with the Vi phages has been responsible for a major epidemic in Tajikistan. Most often, isolates from the Indi...