Enteroaggregative Escherichia coli (EAEC) are highly heterogeneous in virulence; we wanted to understand the pathogenic potential of EAEC isolated various clinical and non-clinical sources in an animal model. We infected male BALB/c mice in six mice/group with 50 EAEC isolates, isolated from clinical and non-clinical sources. We studied colonization, weight loss, stool shedding, inflammatory markers and its relationship with 21 virulence genes and phylogroups, EAEC organ burden and histopathological changes. We detected significantly more inflammatory changes and fecal lactoferrin and calprotectin levels in mice infected with EAEC isolated from symptomatic cases. In clinical EAEC isolates, the presence of chromosomal genes {(aap (46%), aaiC (23.3%), and SPATEs (pet (13.3%), sat (20%), sigA and pic (6.6%)}, adhesive variants {(agg4A (53.3%), aggA (53.3%), aafA (36.6%), agg3A (40%)} of EAEC, and master regulator gene aggR (66.6%) were associated with higher levels of lactoferrin and calprotectin. Also, 70% (9/13) of EAEC isolated from acute diarrheal cases bearing chuA (70%) in our study were assigned to group B2 (4 isolates) and D (5 isolates). Real-time PCR analysis revealed that colonization by EAEC strains from different clinical and non-clinical sources occurs up to 10-15 days of life. Even from non-diarrhoeal stools and non-clinical sources, had the potential to cause prolonged colonization, weight loss, and inflammation in the intestine though the degree varied. Moreover, better understanding of EAEC pathogenic pathways is desperately needed in different clinical scenarios.