Captive green iguana is a reservoir of diarrheogenic Escherichia coli pathotypes

Abstract

The green iguana appears to be a reservoir for bacteria causing gastrointestinal infections in humans. The presence of diarrheogenic E. coli (DEC) pathotypes, however, has not been studied in this reptile. The aim of the current work was to investigate the prevalence of DEC in the intestines of 240 captive green iguanas, their phylogenetic groups, and the antibiotic susceptibility profile. E. coli strains were isolated from 41.7% of the intestinal content of green iguanas. DEC strains was identified in 25.9% of the screened population and were detected in the majority (62%, p=0.009] of those reptiles carrying E. coli strains. Among DEC strains, STEC strains carrying the stx1 gene were the most prevalent pathotype isolated (38.7%), followed by EAEC and ETEC (27.4% each). Genetic markers of DEC strains belonging to the EHEC pathotype were not detected. More than a half of DEC strains were classified into the Clade I-II phylogroup (64.5%), followed by the phylogroup A (14.5%). The antibiotic susceptibility method demonstrated that a high proportion of DEC strains were resistance, or non-susceptible, to carbenicillin, amikacin, and ampicillin (85, 74, and 66%, respectively). We conclude that the green iguana kept in captivity is a reservoir of DEC strains bearing resistance to first-line antibiotics, including penicillins. Given the increase presence of the green iguana in Latin American households, these reptiles represent a potential source of transmission to susceptible humans and therefore a potential source of gastrointestinal disease.\n\nImportanceLatin-American countries present a high burden of diarrheal disease. In this part of the world, besides common pathogens, diarrheal diseases are also caused by pathogenic types of E. coli referred as \"diarrheagenic E. coli\" (DEC). While inhabitants of Latin American countries suffer of self-limiting diarrhea when infected with DEC, a main target of these strains are tourists from developed countries who are not exposed to DEC strains. Efforts are in place to decrease the burden of DEC-associated diarrheal disease. As such, this study investigated a potential reservoir of DEC strains that had been underestimated, the green iguana. These reptiles are very common in Latin American households and are found virtually everywhere in Mexico, Central and South America. We found that 25% of green iguanas carried DEC strains in their intestines. We also demonstrated a high prevalence of antibiotic resistance in these strains, posing a potential risk to humans.