neem preparations showed toxicity to cultures of 14 common fungi, including members of the following genera:
  • Trichophyton—an "athlete's foot" fungus that infects hair, skin, and nails;

  • Epidermophyton—a "ringworm" that invades both skin and nails of the feet;

  • Microsporum—a ringworm that invades hair, skin, and (rarely) nails;

  • Trichosporon—a fungus of the intestinal tract;

  • Geotrichum—a yeast like fungus that causes infections of the bronchi, lungs, and mucous membranes; and

  • Candida—a yeast like fungus that is part of the normal mucous flora but can get out of control, leading to lesions in mouth (thrush), vagina, skin, hands, and lungs.


In trials neem oil has suppressed several species of pathogenic bacteria, including:

  • Staphylococcus aureus.3 A common source of food poisoning and many pus-forming disorders (for example, boils and abscesses), this bacterium also causes secondary infections in peritonitis, cystitis, and meningitis. Many strains are now resistant to penicillin and other antibiotics, one reason for the widespread occurrence of staphylococcal infections in hospitals.

  • Salmonella typhosa.4 This much-feared bacterium, which lives in food and water, causes typhoid, food poisoning, and a variety of infections that include blood poisoning and intestinal inflammation. Current antibiotics are of only uncertain help in treating it.

However, neem has many limitations as an antibiotic. In the latter test, neem showed no antibacterial activity against certain strains of the above bacteria, and none against Citrobacter, Escherichia coli, Enterobacter, Klebsiella pneumoniae, Proteus mirabilis, Proteus morgasi, Pseudomonas aeruginosa, Pseudomonas EO1, and Streptococcus faecalis.


In India, there is much interesting, but anecdotal, information attributing antiviral activity to neem. Its efficacy-particularly against


Schneider, 1986.


Patel and Trivedi, 1962.

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