Vancomycin and amikacin in cell cultures for virus isolation

Contamination of cell cultures for virus isolation has been increasingly encountered. By reviewing and changing the antimicrobials incorporated in cell culture media, we aim to control this problem. Contaminated cell culture fluids were inoculated for bacterial and fungal isolation, identification and antibacterial susceptibility testing. Based on the above results, vancomycin and amikacin were chosen to replace the penicillin and gentamicin used conventionally. Analysis was carried out on various characteristics of cell culture with respect to antimicrobial change. All contaminating Gram-positive bacteria were susceptible to vancomycin while about 80% of the Gram-negative bacteria were sensitive to amikacin. The new antimicrobial combination was not toxic to cell cultures and both antimicrobials were found to remain stable in media for over six months. The virus isolation rate was maintained after antimicrobial change while the contamination rate was reduced from nearly 10% to 1.5%. We thus conclude that vancomycin and amikacin can well replace the conventional penicillin and gentamicin to be incorporated into maintenance and transport media to control the emerging problem of viral culture contamination.