**6. Conclusions**

Selected herbs, spices, fruits and vegetables contain high polyphenol concentrations. They show pronounced antibacterial activity acting against a plethora of

pathogenic Gram(−) and Gram(+) bacteria as *P. aeruginosa*, *S. aureus*, *Streptococcus epidermidis, K. pneumoniae*, *E. coli*, *L. monocytogenes*, *Acinetobacter* sp., *Proteus* sp., *Micrococcus* sp., and *Bacillus* sp. Extraction of polyphenols is challenging and depends on the method, solvent, solvent percentage, temperature of isolation and plant sample. Plant polyphenolic extracts obtained at 80°C possess higher antibacterial activity compared to those extracted at 100°C. Numerous herbs, spices, fruits, and vegetables rich in polyphenols are valuable sources of novel highly effective antimicrobial substances.
