Strict compliance with Biosaftey level-2 (BSL-2) practices may be required if the modified strains are still associated with their pathogenic characteristics.

All Salmonella is considered as pathogenic, therefore the use of P2 safety level lab is mandatory. If not possible, you must find a surrogate in bibliography according to the application you want to investigate. 

Read the recent instructions of WHO in this respect You can downloaded via google schoolar