Antimicrobial Activity of ChiNH/Q

To evaluate the antimicrobial effects of ChiNH/Q, five strains of the pathogen, including Staphylococcus aureus (S. aureus) (ATCC 12600), Listeria monocytogenes (L. monocytogenes) (PTCC 1297), Escherichia coli (E. coli) (PTCC 1395), Klebsiella pneumoniae (K. pneumoniae) (PTCC 1290) and Candida albicans (C. albicans) (PTCC 5072) were obtained from the National Cell Bank of Iran (NCBI, Pasteur Institute, Tehran).

Antimicrobial effects of broth microdilution were used according to the CLSI standard method.^53,54 Briefly, to examine the Minimum Inhibitory Concentration (MIC), ChiNH/Q and blank (1000 µg/mL), Q (5000 µg/mL), Ceftriaxone/Fluconazole (200 µg/mL) sterile media, Mueller-Hinton broth for bacteria and Sabouraud Dextrose broth agar (SDA) for C. albicans were prepared. Then, different concentrations of stocks were added to the wells and the microbial suspension equivalent to Half McFarland (1.5×10⁸ CFU/mL) was added to the wells and kept in a 37°C incubator for 24 hours. After this time, salts of 2,3,5- Triphenyltetrazolium chloride were used to evaluate microbial viability. Pink wells indicate microbial life and non-color wells indicate microbial inhibition.⁵³ After calculating the MIC, 5 µL was cultured on Mueller-Hinton agar (for bacteria) and SDA (for C. albicans) with 24 min incubation, and then incubated for 24 h. At 37°C, the first concentration where no colony was found, reported as the Minimum Bactericidal Concentration and Minimum Fungicidal Concentration (MBC/MFC).