Penicillin has good antibacterial effect on hemolytic streptococci and other streptococci, Streptococcus pneumoniae and non-penicillinase-producing staphylococci. It has moderate antibacterial effect on enterococci. Neisseria gonorrhoeae, Neisseria meningitidis, Corynebacterium diphtheriae, Bacillus anthracis, Actinomyces bovis, Streptobacillus candida, Listeria monocytogenes, Leptospira and Treponema pallidum are sensitive to this product. This product also has certain antibacterial activity against Haemophilus influenzae and Bordetella pertussis, and other Gram-negative aerobic or facultative anaerobic bacteria are less sensitive to this product. This product has good antibacterial effect on Clostridium, Peptostreptococcus anaerobic bacteria and melanin-producing Bacteroides, but has poor antibacterial effect on Bacteroides fragilis. Penicillin exerts its bactericidal effect by inhibiting bacterial cell wall synthesis.

Penicillin has good antibacterial effect on Streptococcus such as hemolytic Streptococcus, Streptococcus pneumoniae and Staphylococcus that does not produce penicillinase. It has moderate antibacterial effect on enterococci, and Neisseria gonorrhoeae, Neisseria meningitidis, Corynebacterium diphtheriae, Bacillus anthracis, Actinomyces bovis, Streptobacillus candida, Listeria monocytogenes, Leptospira and Treponema pallidum are sensitive to this product. This product also has certain antibacterial activity against Haemophilus influenzae and Bordetella pertussis, and other Gram-negative aerobic or facultative anaerobic bacteria are less sensitive to this product. This product has good antibacterial effect on Clostridium, Peptostreptococcus anaerobic bacteria and melanin-producing Bacteroides, but has poor antibacterial effect on Bacteroides fragilis. Penicillin exerts its bactericidal effect by inhibiting bacterial cell wall synthesis.

Ampicillin sodium is a broad-spectrum semi-synthetic penicillin. This product has a strong antibacterial effect on hemolytic streptococci, Streptococcus pneumoniae and non-penicillinase-producing Staphylococci, which is similar to or slightly inferior to penicillin. Ampicillin also has a good antibacterial effect on viridans streptococci, and is better than penicillin on enterococci and Listeria. This product has antibacterial activity against Corynebacterium diphtheriae, Bacillus anthracis, Actinomyces, Haemophilus influenzae, Bordetella pertussis, Neisseria and anaerobic bacteria except Bacteroides fragilis. Some Proteus mirabilis, Escherichia coli, Salmonella and Shigella are sensitive to this product. Ampicillin exerts its bactericidal effect by inhibiting bacterial cell wall synthesis.

This product is an acid-resistant and penicillinase-resistant penicillin, which has good antibacterial activity against penicillinase-producing Staphylococci, but its antibacterial activity against various streptococci and non-penicillinase-producing Staphylococci is inferior to penicillin G. This product exerts its bactericidal effect by inhibiting bacterial cell wall synthesis.