Combination of a betalactam antibiotic ( ampicillin or azlocillin ) or polymyxin B with rifampicin were studied with their administration in succession at various intervals in an experimental model of plague infection of albino mice .
[A method of sequential administration of antibiotics in preventive treatment of experimental plague in albino mice].  Combination of a betalactam antibiotic ( ampicillin or azlocillin ) or polymyxin B with rifampicin were studied with their administration in succession at various intervals in an experimental model of plague infection of albino mice . It was shown that when the administration of the betalactams or polymyxin B preceded the administration of rifampicin, the efficacy of the preventive therapy considerably increased. The time of the intervals was noted to be of importance and should be predetermined for every subsequent administration.
### Instruction:
            Given the context about compound efficacy for the given treatment mentioned within the input, mentioned the compounds 
            that can co-occur for the mentioned treatment

            ### Input:
            [A method of sequential administration of antibiotics in preventive treatment of experimental plague in albino mice].  Combination of a betalactam antibiotic ( ampicillin or azlocillin ) or polymyxin B with rifampicin were studied with their administration in succession at various intervals in an experimental model of plague infection of albino mice . It was shown that when the administration of the betalactams or polymyxin B preceded the administration of rifampicin, the efficacy of the preventive therapy considerably increased. The time of the intervals was noted to be of importance and should be predetermined for every subsequent administration.

            ### Response:
            ampicillin, azlocillin, polymyxin, rifampicin
            