The use of the API 20 NE bacteria classification procedure to identify Pasteurellaceae strains in rodents and rabbits

Abstract

Forty growth-factor independent Pasteurellaceae strains representing most known taxa from rodents and  rabbits were API 20 NE profiled by four laboratory animal diagnostic laboratories using their routine  methodology. Significant differences were found in the number of bacterial strains classified with the  Pasteurellaceae. The results of the four laboratories taken together showed that 136 (85 %) of the 160 tests  carried out with the 40 strains led to classification with the family. The 23 Pasteurellaceae strains from  species (Pasteurella aerogenes, P. multocida, P. pneumotropica) present in the API 20 NE data base (API  taxa strains) and the 17 strains from taxa not included (non - API taxa strains) were classified with the family  with similar frequency.

Pasteurella species designation differed significantly between the laboratories and full agreement in speciation  was found with only 9 (22.5 %) of the 40 strains. Of the tests carried out with P. multocida and P.  pneumotropica, 42 and 52 % respectively led to misclassification. Conversely 38 % of the profiles  obtained with non- API taxa strains led to identification as P. multocida or P. pneumotropica.  We conclude that identification of Pasteurellaceae to the species level by the API 20 NE system is unreliable,  but the system is useful to classify various Pasteurellaceae taxa from rodents and rabbits with the  bacterial family.