COMPARISON OF FRESH AND FROZEN FECAL SAMPLES FOR DETECTION OF ENTERICSALMONELLAFROM CAPTIVE INDIAN STAR TORTOISES (GEOCHELONE ELEGANS)

Abstract

The use of frozen fecal samples in enrichment media to detect Salmonella spp. strains was evaluated in Indian star tortoises (Geochelone elegans) to determine the utility of this test method for field collection. Fresh fecal samples were collected from 10 captive adult Indian star tortoises. Each sample was split, with one portion in enrichment media at room temperature for 1 or 2 days before submission to a reference laboratory for standard enteric culture. The other was placed in the same enrichment media and frozen at -20°C for 2 wk. Afterwards, it was transferred to a -80°C freezer for 1 mo before submission to the same reference laboratory. These freezer temperatures and holding times were selected to replicate typical field collection procedures. Salmonella enterica was isolated from all 10 fresh samples but from only six frozen samples. Statistically, results showed no significant difference between the two methods; however, this may be due to the limited sample size, and if so, utilization of frozen fecal samples to determine Salmonella spp. prevalence may underestimate the actual prevalence.