Comparative and Veterinary Pharmacology

those that disrupt bacterial cell membranes). They can repopulate the biofilm
following discontinuation of therapy (del Pozo and Patel 2007 ). These cells forfeit
rapid propagation to ensure survival of the bacterial population in the presence of
lethal factors (Keren et al. 2004 ). They can exist in planktonic form or in biofilms

–2

0

2

4

6

a 8

b

c

NonGrowth Suboptimal Optimal Growth

Log10 CFU/mL killed

Control

Meropenem

Cipro

Ofloxacin

Gent

Cefotaxime

–2

0

2

4

6

8

NonGrowth Suboptimal Optimal Growth

Log10 CFU/mL killed

Control

Meropenem

Cipro

Ofloxacin

Gent

Cefotaxime

–2

0

2

4

6

8

NonGrowth Suboptimal Optimal Growth

Log10 CFU/mL killed

Control

Meropenem

Cipro

Ofloxacin

Gent

Nafcillin

Fig. 4(a–c) Relationship between drug, pathogen, growth phase, and antimicrobial cidal activ-
ities. Based upon data from Eng et al. ( 1991 ). Cipro = ciprofloxacin, Gent = gentamicin.
(a) Relationship between growth phase and antimicrobial activity:E. coli(b) Relationship
between growth phase and antimicrobial activity:K. pneumoniae(c) Relationship between growth
phase and antimicrobial activity:S. aureus

252 M. Martinez and P. Silley