RESUMO
OBJECTIVE: Assess the antimicrobial activity of Phramongkutklao antibiotic hydroxyapatite pellets in vitro. MATERIAL AND METHOD: The selected bacteria used in the present study were the standard and drug-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa, which are the common organisms causing infection in Orthopedics. Phramongkutklao antibiotic hydroxyapatite pellets developed by the Orthopedics Department, Phramongkutklao Hospital contained either Vancomycin, Fosfomycin, or Gentamycin. Each preparation was placed on an agar plate inoculated with each bacterium. The inhibition zones were monitored in 24 hours. Then the pellets were moved onto the new inoculated plate every day for 28 days. RESULTS: Compared with the control group, Phramongkutklao antibiotic hydroxyapatite pellets had good inhibitory effect against S.aureus. Vancomycin hydroxyapatite pellets were able to maintain their activity for 28 days whereas Gentamycin hydroxyapatite pellets was effective for only three days. Fosfomycin hydroxyapatite pellets could inhibit MSSA for 13 days and MRSA for 25 days. On the contrary, all three Phramongkutklao antibiotic hydroxyapatite pellets had very low efficacy against Paeruginosa. CONCLUSION: Phramongkutklao antibiotic hydroxyapatite pellets were able to inhibit the growth of S. aureus both MSSA and MRSA while the activity against P. aeruginosa needs to be developed.