Glutamine synthetase (glnA), on the other hand, was identified as a fitness factor for CAUTI, and the importance of this gene to P. mirabilis fitness was confirmed by direct co-challenge with wild-type P. mirabilis. Thus, there appears to be a differential requirement for metabolic pathways as well as nitrogen assimilation pathways during UTI and CAUTI. Here, GLUL is linked to bacterial urinary tract infection.