Selective isolation of Pseudomonas stutzeri from vertebrate faeces on Rambach agar

Faecal samples collected from 308 wild birds of 25 species and 19 rodents of 3 species in South Moravia (Czechland) were pre-incubated in Müller-Kauffmann tetrathionate broth at 42 degrees C for 24 h and then streaked onto Rambach agar plates which were incubated at 37 degrees C for 48 h. Seventeen out of 22 isolates forming orange-red colonies on Rambach agar were identified as Pseudomonas stutzeri, the rest as Pseudomonas sp. and Alcaligenes sp. The colonies of P. stutzeri were either dry, wrinkled and adherent to the agar (resembling Bacillus) or smooth, less adherent (mimicking Salmonella). P. stutzeri was recovered from five species of vertebrates caught in farmland habitats: the house sparrow (Passer domesticus), the tree sparrow (P. montanus), the great warbler (Acrocephalus arundinaceus), the wood mouse (Apodemus sylvaticus) and the common vole (Microtus arvalis). The overall isolation rate was 4.5% in birds (12.6% in house sparrows) and 15.8% in rodents. The procedure can be useful for the isolation of P. stutzeri in clinical and environmental studies.