Background:

Bicyclomycin benzoate is a novel antibiotic produced by S. sapporonensi [1]. Bicyclomycin shows an inhibitory effect on Gram-negative bacteria, such as E. coli, Klebsiella, Shigella, Salmonella, Citrobacter, E. cloacae, and the pathogenic group of Neisseria [2]. Bicyclomycin benzoate is inactive against Proteus, P. aeruginosa, and Gram-positive bacteria [1,2].

In vitro: The MIG of bicyclomycin for E.coli NIHJ JC-2 was 25-50 μg/ml. Bicyclomycin (25-50 μg/ml) completely inhibited formation of visible colonies or turbidity of this organism on agar plates, in nutrient broth, and in heart infusion broth [2]. Bicyclomycin inhibited ATPase activity in the presence of poly(dC) and ribo(C)10. The approximate IC50 value for inhibition of transcription termination at Rho-dependent sites was 5 μM. The inhibitory effect of bicyclomycin on Rho-dependent transcripts was accompanied by the appearance of a new set of transcripts. In the presence of poly(dC), bicyclomycin reversibly inhibited the ribo(C)10-stimulated ATPase activity. The extrapolated Ki for bicyclomycin was 2.8 μM without ribo(C)10, which was increased to 26 μM in the presence of ribo(C)10 [3].

In vivo: Bicyclomycin showed therapeutic activity for infections with several strains of E. coli which were resistant to the control antibiotics. The ED50 of bicyclomycin for infection with GP-resistant E.coli 312 was 3.05 (1.47-7.66) mg/mouse [2].

参考文献:
[1] Miyoshi, T. ,Miyairi, N.,Aoki, H., et al. Bicyclomycin, a new antibiotic. I. Taxonomy, isolation and characterization. J.Antibiot.(Tokyo) 25(10), 569-575(1972).
[2] Nishida, M. ,Mine, Y.,Matsubara, T., et al. Bicyclomycin, a new antibiotic. III. In vitro and in vivo antimicrobial activity. J.Antibiot.(Tokyo) 25(10), 582-593(1972).
[3] Magyar A, Zhang X, Kohn H, et al.  The antibiotic bicyclomycin affects the secondary RNA binding site of Escherichia coli transcription termination factor Rho[J]. Journal of Biological Chemistry, 1996, 271(41): 25369-25374.