Isolation and characterization of Campylobacter, Helicobacter, and Anaerobiospirillum strains from a puppy with bloody diarrhea

Abstract

We carried out a microscopic examination of stools from a 2-month-old female puppy with bloody diarrhea, and this revealed large numbers of different spiral-shaped bacteria. To isolate these organisms, a rectal swab specimen was inoculated onto plates of Skirrow’s agar and incubated at 37 °C for 6 days in a microaerobic atmosphere. Finally, a total of six different spiral-shaped bacteria (strains G1104, 94105, FR106, B0101, 3J102, and J2103) were isolated. Based on their morphology, biochemical traits, whole-cell protein profiles, and analysis of their 16S rDNA sequences, they were identified as Campylobacter upsaliensis, Helicobacter cinaedi, ‘ Flexispira rappini’, two Anaerobiospirillum spp. with different morphologies, and Helicobacter sp., respectively. Analysis of 16S rRNA gene sequence data for strains 94150 ( H. cinaedi) and FR106 ( F. rappini) revealed that this approach has limitations when identifying isolates to the species level because of a high degree of sequence homology between these species (>99%) and considerable sequence variation among different isolates within these species. The dog was treated orally with amoxicillin for 3 days, which resolved the diarrhea. However, 1 day after the last dose the bloody diarrhea recurred but regarded to six more days amoxicillin treatment. This suggests a bacterial cause for the diarrhea. The approach to identification to microaerobic spiral-shaped bacteria in diarrheic dogs can be applied further to characterize their role in diarrhea illness.