Background:

Clavulanate is a metabolite existed in cultures of Streptomyces clavuligerusa with activity against both Gram-positive and Gram-negative bacteria. Clavulanate is a first clinically useful broad-spectrum β-lactamase inhibitor. Clavulanate formulations have been widely used in the treatment of a broad range of clinical infections [1].

Clavulanate was least active against Pseudomonas spp. and the enterococci with MICs of 125–512 mg/L, followed by members of the Enterobacteriaceae and H. influenzae with MICs of 12–125 mg/L. Clavulanate showed great activity against Bacteroides spp. and other anaerobes, M. catarrhalis, staphylococci and streptococci with MICs of 4–50 mg/L. Clavulanate was active against Neisseria spp. with MICs of 1.25–4 mg/L [1].

In an infection model of L. pneumophila pneumonia leucopenic weanling rats, clavulanate effectively prevented the development of infection. In a mouse lethal thigh infection model with two susceptible strains of S. pneumoniae, treatment with clavulanate decreased the mortality [1].

Reference:
[1] Finlay J, Miller L, Poupard J A.  A review of the antimicrobial activity of clavulanate[J]. Journal of Antimicrobial Chemotherapy, 2003, 52(1): 18-23.