PREVALENCE OF FECAL SHEDDING OF SALMONELLA ORGANISMS AMONG CAPTIVE GREEN IGUANAS AND POTENTIAL PUBLIC-HEALTH IMPLICATIONS

Objective-To determine prevalence of fecal shedding of Salmonella orga nisms among captive green iguanas (Iguana iguana). Design-Cohort study . Animals-12 captive green iguanas. Procedure-Iguanas were isolated in an environmental chamber, and fecal samples were collected weekly for 10 consecutive weeks. Samples were incubated aerobically in tetrathio nate broth for 18 to 24 hours. Aliquots were then transferred to Hekto en and Salmonella-Shigella agar plates and incubated for an additional 18 to 24 hours. Isolated colonies were subcultured on nutrient agar s lants, and Salmonella isolates were serogrouped and serotyped. Results -All 12 iguanas were found to be shedding Salmonella organisms at leas t once during the study, and multiple serotypes were isolated from 7 o f the 12. Salmonella organisms were isolated from 88 of 106 (83%) feca l samples; 21 samples contained multiple Salmonella serotypes. Overall , 11 Salmonella serotypes were identified. In 74 of 100 instances, whe n a particular Salmonella serotype was isolated from an individual igu ana, the same serotype was also isolated from a subsequent fecal sampl e from that iguana. Clinical implications-Results suggested that most iguanas have a stable mixture of Salmonella serotypes in their intesti nal tracts and intermittently or continuously shed Salmonella organism s in their feces. Veterinarians should advise their clients on precaut ions for reducing the risk of acquiring these organisms from their pet s. Public health officials trying to determine whether an iguana is th e source of a specific Salmonella serotype that caused infection in hu man patients should submit at least 3 fecal samples collected from the iguana 1 week apart for bacterial culture.