Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 1996
Publication Date: N/A
Technical Abstract: Restriction endonuclease analysis (REA) is utilized at the NADC to discriminate among P. multocida strains of the same serotype. The method is particularly useful for strains which cause haemorrhagic septicemia (HS). Chromosomal DNA from lysed bacteria is digested with an endonuclease; the endonucleases HhaI and HpaII are particularly useful for differentiating P. multocida. Following gel electrophoresis and staining, band patterns (fingerprint profiles) produced by endonuclease digestion are viewed and photographed in ultraviolet light. To analyze and compare fingerprint profiles, reverse negative photographs of a gel are made, scanned to create an image file, and the image file is processed by a computer analysis program. Using HhaI, most diversity amongst HS strains occurs with serotype B:2 strains; 17 different fingerprint profiles have been recognized to date. Twelve DNA fingerprint profiles have been found among serotype B:3,4 strains, whereas only 1 DNA fingerprint profile was found among serotype E:2 strains. When HpaII was used with serotype E:2 strains, five different DNA fingerprint profiles were recognized. We have observed a particularly interesting phenomenon comparing serotype B:3,4 strains isolated from healthy-carrier elk and B:3,4 strains isolated from HS outbreaks in elk. A DNA fingerprint profile designated HhaI-036 was isolated from outbreaks of HS in elk that occurred in 1986, 1987 and 1993 in the United States. Serotype B:3,4 isolated from healthy-carrier elk in the same geographic region in 1992 had four different fingerprint profiles. However, none of the four DNA fingerprint profiles from healthy-carrier elk was identical with HhaI-036.