To explore the role of GlnA-1 in A. baumannii, either intracellularly or extracellularly, our study aimed to evaluate glutamine synthetase activity in a glnA1 transposon mutant (glnA1::Tn) and correlate these findings with outcomes from an infection model to assess the impact of glnA1 disruption on virulence. This evidence concerns the gene GLUL and infection.