Captive Green Iguana Carries Diarrheagenic Escherichia coli Pathotypes

Abstract

The green iguana appears to be a carrier for bacteria causing gastrointestinal infections in humans. The presence of diarrheagenic 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% (N = 100/240) 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. We conclude that the green iguana kept in captivity is a carrier 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.

Evidence of Another Anthropic Impact on Iguana delicatissima from the Lesser Antilles: The Presence of Antibiotic Resistant Enterobacteria

“…This could be regarded as an indication of the disturbance to the iguanas caused by the contamination of their environment by human activity. It should be noticed that the frequency of E. coli (32%) described in this work refers to the DOM species of the cloaca-associated enterobacteria, rather than to the simple presence of this bacterium in the samples, as in other studies, e.g., [8][9][10][11]. An even clearer indication comes from the comparison of antibiotic resistance frequency and profiles.…”

“…Most isolates belonged to ubiquitous genera, usually recovered both from the environment and from the gut of animals and man (i.e., Enterobacter, Citrobacter, Klebsiella and Raoultella), as well as being frequently isolated from human clinical samples [17]. Salmonella is quite common in the cloaca of many reptiles including iguanas [8][9][10][11]18], whilst E. coli is more commonly associated to the gut of warm-blooded animals and man, and are also used as an index of fecal contamination to assess water quality.…”

“…However, wherever the proximity and/or promiscuity between man and wildlife is high, resistant bacterial isolates and/or resistance genetic determinants can circulate more easily in wild animals, thus, antibiotic resistant bacteria are likely observed in anthropogenic biased sites (for a review see Allen et al [6]). The diffusion of resistant strains and/or resistance determinants related to antibiotic abuses in both husbandry and agricultural practices, have persuaded researchers to look mainly at animals as the reservoir for bacteria that potentially threaten human health (e.g., Woodward et al [7]; Sylvester et al [8]; Bautista-Trujillo et al [9]). However, especially when endangered animal species are considered, the exchange of microorganisms caused by a high anthropic pressure should be assessed as a further element of risk and used as a tool to evaluate its extent.…”

“…both husbandry and agricultural practices, have persuaded researchers to look mainly at animals as the reservoir for bacteria that potentially threaten human health (e.g., Woodward et al [7]; Sylvester et al [8]; Bautista-Trujillo et al [9]). However, especially when endangered animal species are considered, the exchange of microorganisms caused by a high anthropic pressure should be assessed as a further element of risk and used as a tool to evaluate its extent.…”

Florida's Introduced Reptiles: Green Iguana (Iguana iguana)

“…In addition to being physical hazards, green iguanas in captivity are also known carriers of E. coli and Salmonella bacteria. In a study of captive green iguanas in Mexico, nearly 40% were found to carry E. coli strains that were resistant to antibiotics (27). However, there is no scientific evidence that indicates wild green iguanas in Florida transmit pathogens to humans.…”