The consistency with which virulence factors in particular, and most genes in general, are present within each genome is remarkable.
Brought up in a communist household, one of my own strongest memories of 50 years ago is of the virulence, shocking at the time, with which the Daily Worker attacked the newly dead Churchill.
Inclusion proteins are an important family of chlamydial proteins, associated with virulence, which target the host inclusion membrane.
Moreover, the speed with which shifts in virulence can apparently occur in Bd suggests that this pathogen has a considerable capacity to respond to novel conditions.
The speed with which resistance and virulence genes move between strains by lateral gene transfer in S. aureus is clinically worrisome in patients chronically colonized and receiving many antibiotics and represents a model for emergence of uncontrollable super bugs in a specific niche.
This agrees with virulence data which suggests that despite the emergence of new highly aggressive isolates after 2000 in some European countries (Denmark and Sweden), these have not yet appeared in UK fields (unpublished observations, Rosemary Bayles).
It is believed that understanding the regulatory mechanisms with which P. aeruginosa governs virulence gene expression may hold the key to develop alternative therapeutic interventions to control and prevent the bacterial infections (Fig. 1).
