Choanal and cloacal aerobic bacterial flora in captive green iguanas: a comparative analysis

The aims of this study were to characterize the choanal and cloacal aerobic bacterial flora in healthy captive green iguanas and to compare it with the bacterial flora of the biofilm present in the water container of each terrarium. Samples were collected from the choana and the cloaca of 20 healthy captive adult green iguanas and from the biofilm of 15 water containers. The final identification of aerobic bacteria was performed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Salmonella positive samples were serotyped. The most common strains observed at each test location were from 1) choanae: Staphylococcus spp. , Enterobacter cloacae and Comamonas testosteroni; 2) cloacae: Citrobacter spp. , Salmonella spp. and Corynebacterium spp. ; and 3) biofilms: Pseudomonas spp. , Salmonella spp. and Acidovorax spp. We showed that apart from Salmonella spp. , the choanal and cloacal bacterial flora differed from the microorganisms present in the biofilm of the animal’s water container. These data revealed that healthy captive adult green iguanas harbored several aerobic bacterial strains that in immunosuppressed reptiles may act as opportunistic pathogens. Also, several of the aerobic bacteria identified in samples are potential zoonotic agents. Characterization of the normal background flora in captive reptiles and their environment can contribute to an understanding of the spread of bacterial contamination and the risk of potential zoonotic diseases for people in contact with these animals. Reptiles, biofilm, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, serotype Previous studies in clinically healthy captive lizards showed a predominance of Pseudomonas spp. , Aeromonas spp. , Serratia spp. and Enterobacter spp. in the oral cavity of green iguanas (Barten 2002) and Citrobacter spp. , Enterobacter spp. , Escherichia coli, Klebsiella oxytoca, Salmonella spp. , Pseudomonas aeruginosa, Corynebacterium spp. , Staphylococcus spp. , and Streptococcus spp. in the cloaca of giant lizards (Martinez Silvestre et al. 2003). These studies have helped us to understand the normal bacterial flora in captive lizards and to interpret the significance of bacterial strains in ill individuals. Pet green iguanas are kept for many years in indoor terrariums. This situation leads us to consider the influence of the bacterial population in the biofilm that forms on the water container that is used by the lizard to drink from and bathe in, on the bacterial community of the lizard. The aims of this study were to characterize and compare the aerobic bacterial flora between the choanal and cloacal sites in healthy captive adult green iguanas, and with the bacteria of the water container in their terrariums. This information will explore the hypothesis that the biofilm in water containers may perpetuate and spread bacterial contamination between animals and between terrariums. Furthermore, these data will contribute to knowledge of the normal background flora in pet iguanas and their environment, and for understanding the risk of potential zoonotic diseases for people in contact with these animals.