TABLE 1.

Bacteriocin phenotypes of bacteriocin-resistant mutants and corresponding wild-type L. monocytogenes strains

StrainaPhenotypeb for:Reference or source
Nisin APediocin PA-1Leucocin ACarnobacteriocin B2
412ESESESS16
412NISSS15
412CSIIIThis workc
412PSHRHRHR16
412C2SHRHRHR14
358ESESSS15
358NISIS15
358CSHRHRHRThis workc
409SESESS15
409NISIS15
B73ESESESES13a
B73-V1ESIIS43
B73-V2ESIIS43
B73-MR1ESHRHRHR33
B73PESHRHRHRThis workd
31SESESS16a
31PSIII16a
O57ESSSS1a
3.33AESHRHRHR14
O57CESHRHRHRThis workc
EGDeESESESES13b
EGY2ESHRHRHR12
  • a Spontaneous mutants were isolated from wild-type strains 412, 358, 409, B73, 31, and O57. Mutants were isolated by selection as follows: N, with nisin A; P, with pediocin PA-1; C, C2, and A, with carnobacteriocin B2; and MR1, V1, and V2, with leucocin A. EGY2 was made from wild-type EGDe by in-frame deletion in the mptD gene.

  • b ES, S, I, and HR indicate extremely sensitive, sensitive, intemediately resistant, and highly resistant, respectively.

  • c Isolated with 100 C-AU of carnobacteriocin B2 ml−1 and 0.1% Tween 80 on TSA plates incubated at 5°C for 24 h and then at 30°C.

  • d Isolated with 2,560 P-AU of pediocin PA-1 ml−1 on TSA plates (pH 6.5) incubated at 30°C.