Good antivirus for linux

[Me.B]

I'm installing antivirus on servers mainly to scan users files for php rootkits that could cause a lot of mess with spam/cpu use.

Also We need antivirus in email gateways despite we are getting less virus in email (attachment) while facing more phishing attacks (AV can't do a lot here as it's links).

I have many severs running without antivirus as most of the websites if not all are mine and no one other have access beside Web front end (Windows & linux), but on shared hosting server I have set AV on both windows/linux.

Also if you are experienced once you had fought rootkit you will smell it quickly that something is wrong in the server. I remeber I was unable once to kill a rootkit but managed to jail it so it was almost frozen and gained time until I moved my data, as it was a production server.

M B