Bactericidal Activities of Rat Defensins and Synthetic Rabbit Defensins on Staphylococci, Klebsiella pneumoniae (Chedid, 277, and 8N3), Pseudomonas aeruginosa (Mucoid and Nonmucoid Strains), Salmonella typhimurium (Ra, Rc, Rd, and Re of LPS Mutants) and Escherichia coli