Yes brine does kill bacteria on the meat.
As long as you're soaking the meat all the way in the salt water brine the brine will kill the bacteria on the meat and also when you brine meat it prevents the meat from spoiling as fast.
Just make sure you brine the meat long enough and make sure the meat is fully submerged in the brine solution to kill the meat.
When soaking meat in brine you are supposed to soak the meat in the brine for an hour for each lb of the meat.
For example if you have 10 lbs of meat that needs soaked in brine then you would soak the 10 lb meat in the brine for 10 hours.
You do not want to soak meat in the brine for longer than needed because when you soak the meat in brine to long the meats proteins break down too far, turning it into unappetizing mush.
So as long as you're just soaking the meat in the brine for an hour for each lb of the meat then you are doing it correct.
Just put the meat in the brine and set a timer for an hour for each lb of meat and then when the time is up remove the meat from the brine.
I've made the mistake of leaving the meat in brine too long and it turned it into mush so I use a timer to remind myself.