To perform the antimicrobial tests of clays, a sample of 0.1 g of clay was added to the 10 mL Mueller Hinton Broth (MHB). After 5 h, the clay sample was inoculated with 0.1 mL of S. aureus culture. Control experiments without clay and samples with unmodified clay were performed under the same conditions. Control and samples were incubated at 37 _ C for 24 h. Afterwards, 0.1 mL of each was sowed in agar–triptone–soybean (TSA) plates and incubated for 24 h at 37 _ C. Finally, viable cells were counted.