Antimicrobial properties of the polyaniline composites against pseudomonas aeruginosa and klebsiella pneumoniae

CuO∗TiO₂∗Or SiO₂was decorated on polyaniline (PANI) by a sonochemical method, and their antimicrobial properties were investigated for two common Gram-negative pathogens: Pseudomonas aeruginosa (PA) and Klebsiella pneumoniae (KP). Without PANI, CuO, TiO₂, or SiO₂with a concentration of 220 μg/mL exhibited no antimicrobial activities. In contrast, PANI-CuO and PANI-TiO₂(1 mg/mL, each) completely suppressed the PA growth after 6 h of exposure, compared to 12 h for the PANI-SiO₂at the same concentration. The damage caused by PANI-SiO₂to KP was less effective, compared to that of PANI-TiO₂with the eradication time of 12 h versus 6 h, respectively. This bacterium was not affected by PANI-CuO. All the composites bind tightly to the negative groups of bacteria cell walls to compromise their regular activities, leading to the damage of the cell wall envelope and eventual cell lysis.