The bouncer realizes that all the IDs that the pathogens were showing him were fake: the official Organism watermark was missing, and the cards were made of cheap paper.
Because he's seen these fake IDs before, he tells his fellow B-cell bouncers to look out for the same thing and easily identifies the rest of the pathogens who came in illegally. He calls the police and keeps the offending pathogens in his line of sight until they come.
The Pathogen Police Department arrive quickly on scene. Because underage pathogens trying to break into the bar is a common occurrence, the officers are able to deal with the hooligans easily because they have experience and deadly weapons.
Unfortunately, Pete the pathogen was one of the organisms apprehended that night. Getting into the Body Bar isn't easy and he is facing consequences for trying to bust in.