Species of Enterobacter cloacae complex (ECC) are widely distributed in the environment and are part of the gut microbiota of both animals and humans. Anolis marmoratus, an endemic and anthropophilic lizard of Guadeloupe, is a natural carrier of ECC and in particular of strains resistant to third generation cephalosporins (3GCR). Bacteria belonging to this complex are also major opportunistic pathogens which draw attention by their involvement in nosocomial infections and the emergence of multidrug resistant clones. Using hsp60 genotyping, ECC is divided into 12 genetic clusters (cluster I-XII) and a loosely knit group (cluster XIII). Strains belonging to clusters III, VI and VIII are prominent in human infections. We collected ECC strains (n=155) isolated from different sources (anoles, environment and clinical samples). We characterized these strains according to their antibiotic resistance phenotypes. Nearly 28% of strains sampled from environment and anoles were resistant to 3GC. This specific resistance was related to the overexpression of the AmpC cephalosporinase. We identified the cluster for each strain by using hsp60 genotyping. Cluster VIII was predominant in A. marmoratus feces (n=37, 38.9%) and in water catchment (n=10, 45.6%). We sequenced 58 strains of C-VIII (33 from clinical isolates: 26 from France and 7 from Guadeloupe, and 25 from anoles). A Maximum likelihood analysis based on core genome alignment revealed a clear split of isolates into two main clusters depending on sources: the first one clustering most of clinical samples together (from France and Guadeloupe, n=29) but also 5 strains isolated from anoles. The second cluster was mainly constituted by strains from anoles (n=20) and by 4 clinical samples. These results suggest first that bacteria resistant to third generation cephalosporins exist in environmental reservoirs in Guadeloupe. Moreover, exchange of ECC C-VIII strains may happen between human and anoles within a One Health appro