Agarose soy casein digest medium for replacement of blood agar for potency determinations of live Pasteurella vaccines

• Published in: Applied and Environmental Microbiology Vol. 55; no. 1; pp. 106 - 108
• Main Authors: Rebers, P.A, Christianson, G.G, Laird, G.A, Symanowski, J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.01.1989
• Subjects: Bacterial Vaccines - standards; Bacteriological methods and techniques used in bacteriology; Bacteriology; BACTERIOSE; BACTERIOSIS; Biological and medical sciences; Colony Count, Microbial; Culture Media; ESSAI; Fundamental and applied biological sciences. Psychology; MEDIO DE CULTIVO; Microbiology; MILIEU DE CULTURE; PASTEURELLA; Pasteurella - growth & development; Pasteurella - immunology; Pasteurella haemolytica; PASTEURELLA MULTOCIDA; PRUEBAS; VACCIN; VACUNA; Pasteurellaceae; Culture medium; Vaccine strain; Microorganism culture; Bacteria; Vaccine; Viability; Pasteurella haemolytica; Colony forming cell; Pasteurella multocida
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.55.1.106-108.1989

Blood agar, prepared with Trypticase soy agar and 5% defibrinated bovine blood, is used for testing the potency of live Pasteurella multocida and Pasteurella haemolytica vaccines, but its potential for variation makes it undesirable to use in a standard assay method. Tests done with RPMI 1640 and Trypticase soy medium indicated that the benefits obtained by adding defibrinated blood to the Trypticase soy agar medium were more likely due to neutralization of toxic components than to the presence of transferrin or iron as growth factors. Reduction of toxic components in the Trypticase soy agar medium was accomplished by replacing agar with agarose and by autoclaving glucose as a separate solution to produce the replacement medium. The replacement medium was prepared by autoclaving three separate solutions--Trypticase soy broth without glucose; glucose; and agarose--cooling to 55 degrees C, and mixing and then pouring the mixtures into petri dishes. The growth obtained with this medium as judged by determination of the number of CFU and the colony sizes of P. multocida or P. haemolytica was equal to or better than those obtained with blood agar