the activities of penicillin g , ampicillin , piperacillin , cefotaxime and ceftriaxone alone and in combination against 130 isolates of escherichia coli , group b streptococci and listeria monocytogenes from neonatal meningitis were assessed by using agar dilution , checkerboard and time-kill techniques .
C0002680
ampicillin
C0031955
piperacillin