LktA deletion mutant of P. haemolytica

摘要

Described are isolated and purified P. haemolytica bacteria, which express a deletion mutant leukotoxin that induces antibodies that neutralize biologically active leukotoxin. The bacteria contain a temperature sensitive plasmid, which replicates at 30oC but not 40oC and have an origin of replication obtained by mutation of a pD80 origin of replication of a 4.3 kb ampicillin-resistance plasmid of P. haemolytica serotype NADC D80.