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. 2012 Jun;56(6):3277–3282. doi: 10.1128/AAC.06315-11

Table 2.

Effects of antibiotics at 1/4 MIC on induction of stx2-harboring bacteriophages and Stx2 productiona

Antibioticb LB226692 (O104:H4)
 LB226806 (O104:H4)
 EDL933 (O157:H7)
stx2-harboring phage titer P value Stx2 titer P value stx2-harboring phage titer P value Stx2 titer P value stx2-harboring phage titer P value Stx2 titer P value
CIP 6.4 × 104 ± 7.5 × 103c <0.001 128.0 ± 0c <0.001 1.4 × 105 ± 9.3 × 103c <0.001 128.0 ± 0c <0.001 6 × 103 ± 8.8 × 102c <0.001 128.0 ± 0c <0.001
MEM 0.98 ± 0.2 0.68 0.67 ± 0.18 0.28 0.95 ± 0.10 0.68 0.51 ± 0.09 0.13 1.0 ± 0.1 0.79 0.50 ± 0.06 0.12
AZM 0.72 ± 0.1 0.43 0.50 ± 0 0.12 0.51 ± 0.11 0.11 0.54 ± 0.13 0.14 0.63 ± 0.09 0.22 0.59 ± 0.04 0.19
RIF 0.12 ± 0.01d 0.011 0.13 ± 0d 0.012 0.39 ± 0.04 0.062 0.25 ± 0.06d 0.025 0.61 ± 0.11 0.21 0.93 ± 0.28 0.65
TGC 0.21 ± 0.02d 0.05 0.58 ± 0.1 0.17 0.16 ± 0.04d 0.014 0.29 ± 0.11d 0.031 0.85 ± 0.12 0.52 0.50 ± 0.14 0.12
FOF 0.97 ± 0.22 0.71 1.2 ± 0.42 0.95 0.96 ± 0.26 0.72 0.75 ± 0.23 0.37 1.8 ± 0.48 0.45 0.87 ± 0.28 0.54
CHL 0.25 ± 0.06d 0.024 0.13 ± 0.02d 0.012 0.13 ± 0.03d 0.012 0.04 ± 0.02d 0.0068 0.61 ± 0.09 0.21 0.55 ± 0.06 0.15
GEN 0.57 ± 0.12 0.17 0.83 ± 0.18 0.53 1.3 ± 0.23 0.89 0.67 ± 0.18 0.29 2.4 ± 0.12 0.24 1.0 ± 0.18 0.96
KAN 1.56 ± 0.42 0.37 0.83 ± 0.18 0.51 0.48 ± 0.09 0.21 0.58 ± 0.18 0.33 1.0 ± 0.11 0.99 0.83 ± 0.18 0.51
a

Fold increases of stx2-harboring phage titers (indicating stx2-harboring phage induction) and Stx2 titers (indicating Stx2 production) in antibiotic-treated cultures compared to those in control, untreated cultures (defined as 1) are presented (for the actual stx2-harboring phage and Stx2 titers in the control cultures, see Materials and Methods). Data are means ± standard deviations for four independent experiments. P values (by unpaired Student's t test) of ≤0.05 are statistically significant (data shown in bold).

b

CIP, ciprofloxacin; MEM, meropenem; AZM, azithromycin; RIF, rifaximin; TGC, tigecycline; FOF, fosfomycin; CHL, chloramphenicol; GEN, gentamicin; KAN, kanamycin.

c

Significantly increased (P < 0.001) compared to control.

d

Significantly decreased (P ≤ 0.05) compared to control.