Antibiotics WAP-8294A, A.sub.1, A.sub.2, A.sub.4, AX, AX-8, AX-9 and AX-13 or pharmeceutically acceptable salts thereof produced by a strain belonging to the genus Lysobacter; a method for producing the foregoing antibiotic WAP-8294A comprising the steps of cultivating, in the culture medium, a microorganism belonging to the genus Lysobacter and having an ability of producing the antibiotic WAP-8294A to produce the antibiotic and accumulate it in the culture medium; then recovering the antibiotic; as well as an antibacterial composition comprising the antibiotic or pharmaceutically acceptable salts thereof are herein disclosed. The novel antibiotic WAP-8294A has an excellent therapeutic effect on infectious diseases developed by infection with Gram-positive bacteria, in particular, MRSA and, therefore, the antibiotic is effective for treating diseases including MRSA infectious diseases developed through infection with Gram-positive bacteria as infectious bacteria.