DETECTION OF PASTEURELLA-PNEUMOTROPICA IN LABORATORY MICE AND RATS BYPOLYMERASE CHAIN-REACTION

A 16S rDNA-based polymerase chain reaction (PCR) method specific for P asteurella pneumotropica was developed. The PCR product, a 395-base pa ir DNA fragment, was amplified from P. pneumotropica and not from 42 o ther bacterial species tested, including four other Pasteurella specie s and Actinobacillus ureae, The PCR method was used to identify 13 pre viously isolated strains that had been identified as P. pneumotropica by conventional methods: 12 were confirmed by PCR; one that was PCR-ne gative was re-examined by biochemical methods and determined to be A. ureae. The PCR detection of P. pneumotropica in nasopharyngeal swab sp ecimens from 121 surveillance animals (15 inbred mice and 5 inbred rat s from 29 animal rooms) had a high carrier state in healthy laboratory animals; for example, rat swab specimens were 89.6% (43/48) positive by PCR, 8.3% were positive by the direct culture-biochemical method, a nd 16.7% were positive by the enrichment culture-biochemical method. T he positive rate for mice (21.9% [16/73]) was lower than that for rats .