A NEW SELECTIVE ENRICHMENT PROCEDURE FOR ISOLATING PASTEURELLA-MULTOCIDA FROM AVIAN AND ENVIRONMENTAL-SAMPLES

A selective enrichment procedure, using two new selective media, was d eveloped to isolate Pasteurella multocida from wild birds and environm ental samples. These media were developed by testing 15 selective agen ts with six isolates of P. multocida from wild avian origin and seven other bacteria representing genera frequently found in environmental a nd avian samples. The resulting media-Pasteurella multocida selective enrichment broth and Pasteurella multocida selective agar-consisted of a blood agar medium at pH 10 containing gentamicin, potassium telluri te, and amphotericin B. Media were tested to determine: 1) selectivity when attempting isolation from pond water and avian carcasses, 2) sen sitivity for detection of low numbers of P. multocida from pure and mi xed cultures, 3) host range specificity of the media, and 4) performan ce compared with standard blood agar. With the new selective enrichmen t procedure, P. multocida was isolated from inoculated (60 organisms/m l) pond water 84% of the time, whereas when standard blood agar was us ed, the recovery rate was 0%.