Antibacterials synergism

Clavulanic acid has only weak antibacterial activity, but is a potent irreversible inhibitor for many clinically important P-lactamases (10—14,57,58) including penases, and Richmond-Sykes types 11, 111, IV, V, VI ([Bacteroides). Type I Cephases are poorly inhibited. Clavulanic acid synergizes the activity of many penicillins and cephalosporins against resistant strains. The chemistry (59—63), microbiology (64,65), stmcture activity relationships (10,13,60—62,66), biosynthesis (67—69), and mechanism of action (6,26,27,67) have been reviewed. 

Scarpignato C, Pelosini I Antisecretory drugs for eradication of Helicobacter pylori Antibacterial activity and synergism with antimicrobial agents. Progr Basic Clin Pharmacol 1999 11 136-180. 

Sakagami, Y., linuma, M., Piyasena, K.C.N.P. and Dharmaratne, H.R.W. (2005) Antibacterial activity of a-mangostin against vancomycin resistant Enterococci VRE) and synergism with antibiotics. Phytomedicine 12(3), 203-208. 

Hugbo PG. Additivity and synergism in vitro as displayed by mixtures of some commonly employed antibacterial preservatives. Can J Pharm Sci 1976 11 17-20. 

ANTiBionc. Clinically, it has broad-spectrum antibacterial properties and can be used systemically and topically often in conjunction with other drugs (it synergizes with f-lactam antibiotics). 

By way of comparison, we might consider the famesol/anacardic acid synergism against P. acnes. Its antibacterial activity against this follicular bacterium was significantly increased in combination with AMIC of anacardic acid isolated from the cashew Anacardium occidentale (Anacardiaceae) apple, nut and nut shell oil (32). More specifically, the MIC of famesol was lowered from 6.25 to 0.78 /tg/ml, in combination with 0.39 ftg/ml of anacardic acid. Interestingly, this synergism was found to be vice versa the MIC of anacardic acid was reduced from 0.78 to 0.2 /tg/ml when it was combined with 3.13 /tg/ml of famesol (33). The mode of action of the combination, however, remains unclear. 

Many groups have blended PU with other polymers that possess inherent antibacterial properties to synergize the beneficial mechaifical properties of PU with the antibacterial properties of other polymers. In particular, zein and chitosan have been used most frequently (Kara et al., 2014 Umiithan et al., 2014). Both zein, a plant protein, and chitosan, derived from chitin, are natural polymers. Both are also cationic, which is thought to dismpt bacterial cell wall interactions (Chen et al., 2000 Ishitsuka et al., 2006 Kuroda and DeGrado, 2005 Tew et al., 2002) as well as having poor mechanical properties, making both polymers good candidates for copolymer blends with PUs. 

It has been proposed that some monoterpenoid constituents of Cannabis, such as ot-pinene or limonene, may synergize the antibacterial action of CBD, CBG, and CBN [79]. Interestingly, a potentiating effect of mono- or sesquiterpenoids present in Cannabis has been postulated also for other activities, and this observation supports arguments that whole plants and their complex preparations are better drugs than individual components isolated from them. 

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