TABLE 1.

Phage titers of β-lactam-induced lysogenic staphylococcal strainsa

Donor strainPhageInducerbPhage titerc
RN27φ80αMC3.4 × 1010
A2.4 × 108
P7.3 × 108
CL2.4 × 108
CE3.2 × 108
NI8.0 × 105
RN451φ11MC3.6 × 109
A3.6 × 106
P2.8 × 106
CL2.3 × 106
CE3.0 × 106
NI1.4 × 105
RN1030 (recA mutant)φ11MC<10
A<10
P<10
NI<10
JP83 [RN27 LexA (G94E)]φ80αA4.5 × 106
NI4.0 × 105
JP84 [RN451 LexA (G94E)]φ11A1.3 × 106
NI3.0 × 104
  • a Results from a representative experiment are shown.

  • b MC, mitomycin C (2 μg/ml); A, ampicillin (10 μg/ml); P, penicillin G (10 μg/ml); CL, cloxacillin (10 μg/ml); CE, ceftriaxone (10 μg/ml); NI, not induced.

  • c Number of plaque-forming phages per milliliter of induced culture, using RN4220 as the indicator strain.