Table 2.

Ribosomal mutations and erythromycin susceptibility in Campylobacter coli strains compared to C. coli DSM 4689 type straine

Strain(s)Erythromycin MIC (μg/ml)23S rRNA gene mutationaL4 mutation(s)L22 mutation(s)L22 insertions
DSM 4689b0.5wt
36>128A2059GS28P, T176Swt
41,c 37–40, 42–44>128A2059GS28Pwt
45>128A2059GS28P, V121A, M192Iwt
46, 47>128A2059GS28P, V121A, V176I, T177S, V184I, M192IA103V
48>128A2059GS28PG58S
49>128A2059GS28P, M192IT95I, A103V, T109A, A111E, A114T, V121A119-TTTKA-120, 124-T-125
50>128A2059GS28P, M192IA103V, T109A, A111E, A114T, V121A119-TTTKA-120, 124-T-125
51d128A2059GS28P, V121A, M192IA103V, T109A, A111E, A114T, V121A119-TTTKA-120, 124-T-125
5216wtS28Pwt
538wtS28P, V121A, V176I, T177S, V184I, M192IA103V
548wtS28P, M192IA103V, T109A, A111E, A114T, V121A119-TTTKA-120, 124-T-125
  • a Position according to Escherichia coli numbering.

  • b Reference strain for the ribosomal proteins L4 and L22.

  • c Only two mutated copies of A2059G.

  • d NMP caused 2-fold decrease in MIC.

  • e Abbreviations: A, Ala; E, Glu; G, Gly; I, Ile; K, Lys; M, Met; P, Pro; S, Ser; T, Thr; V, Val; wt, wild type, based on corresponding sequences of C. coli DSM 4689 type strain. One strain from each row was selected for the efflux pump inhibitor (NMP and PAβN) testing, and only one strain exhibited a 2-fold decrease in MIC.