TABLE 3.
Changes in antibiotic susceptibilitiesa of Lactobacillus species grown in the presence of bile acidsb
| Lactobacillus species and strain | Relative change in growth zonec
|
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| STREP | KAN | GENT | CHLOR | BAC | RIF | ERY | TET | CIP | NAL | OFLX | VAN | |
| L. acidophilus ATCC 332 | 1.4 | 1.4 | 1.8 | — | 1.5 | — | (1.5) | — | — | — | — | — |
| L. acidophilus ATCC 4356 | 2 | 16 | 17 | — | — | (1.5) | — | (1.3) | — | — | — | — |
| L. acidophilus ATCC 4357 | — | 18 | 1.5 | (1.4) | — | — | — | — | — | — | — | — |
| L. acidophilus ATCC 53103 | 14 | 14 | 2.3 | — | — | — | — | — | — | — | — | — |
| L. acidophilus ATCC 53544 | 16 | 16 | 16 | 1.4 | — | — | — | — | — | — | — | — |
| L. acidophilus KS-13 | — | — | 1.4 | — | 1.9 | — | 1.3 | — | — | — | — | 1.6 |
| L. bifidus ATCC 11146 | 16 | 1.6 | 2.2 | — | — | (1.4) | 1.3 | — | — | — | — | 10 |
| L. delbrueckii ATCC 11842 | NG | NG | NG | NG | NG | NG | NG | NG | NG | NG | NG | NG |
| L. delbrueckii DSM 20080 | NG | NG | NG | NG | NG | NG | NG | NG | NG | NG | NG | NG |
| L. fermentum ATCC 23271 | 11 | 10 | 2 | (1.3) | — | — | (20) | — | — | — | — | — |
| L. gasseri ATCC 19992 | 2.1 | 9 | 13 | — | — | — | — | (26) | — | — | — | 1.4 |
| L. gasseri NCK 99 | 1.6 | 17 | 16 | — | 1.5 | (1.3) | (1.3) | — | — | — | — | 1.4 |
| L. johnsonii ATCC 33200 | 14 | 13 | 1.8 | — | — | — | (20) | — | 2.9 | — | — | — |
| L. maltaromicus BCCM 6903 | 12 | 17 | 18 | (1.4) | — | — | — | (1.5) | — | — | — | — |
| L. paracasei ATCC 27092 | (8) | 11 | 2.3 | — | — | — | — | 1.2 | — | — | — | — |
| L. paracasei JCM 1109 | 27 | 20 | 2.3 | — | 1.4 | — | — | — | 1.4 | — | — | — |
| L. plantarum ATCC 14917 | 10 | 12 | 14 | 1.4 | 1.4 | (1.4) | — | — | — | — | — | — |
| L. plantarum WCFS1 | 12 | 14 | 1.4 | 1.2 | — | (1.3) | — | (1.2) | 11 | — | — | — |
| L. reuteri ATCC 23272 | — | — | 1.3 | — | — | — | — | — | — | — | — | — |
| L. ruminis ATCC 25644 | 1.7 | 15 | 1.8 | — | — | — | — | — | — | — | — | — |
| Surveillance strains | ||||||||||||
| L. murinus NCTR 2479 | 12 | 1.5 | 2 | — | — | — | — | — | 1.2 | — | — | — |
| L. murinus NCTR 2478 | 1.2 | 1.2 | 1.5 | (1.3) | (1.4) | (1.3) | — | (1.2) | — | — | (1.2) | — |
| L. murinus NCTR 2489 | 17 | 1.4 | 1.8 | 1.2 | — | — | — | — | — | — | — | — |
| L. murinus NCTR 2487 | 14 | 1.2 | 1.3 | (1.3) | (1.3) | (1.3) | — | (1.2) | — | — | (1.2) | — |
| L. murinus NCTR 976 | 12 | 12 | 1.4 | — | — | (2) | — | (1.2) | — | — | — | — |
| L. murinus NCTR 2744 | 16 | 18 | 1.5 | — | — | — | — | — | — | — | — | — |
| L. murinus NCTR 2745 | 1.7 | 16 | 1.7 | — | — | — | — | — | — | — | — | — |
| L. murinus NCTR 684 | 16 | 13 | 20 | — | — | — | — | 1.3 | — | — | (1.4) | — |
| L. murinus NCTR 688 | 17 | 17 | 1.6 | — | — | — | (1.2) | (1.2) | — | — | — | — |
| L. murinus NCTR 2507 | 12 | 11 | 1.5 | — | — | 1.3 | — | — | — | — | — | — |
Susceptibilities were evaluated by measuring (in millimeters) zones of growth inhibition in standard disc diffusion assays.
MRS plates were supplemented with 0.5% fractionated ox gall powder containing a complex mixture of bile acids.
Relative changes in growth zones were computed as ratios by dividing the size of the zone of inhibition on MRS plates containing bile acids by that of MRS control plates. For values of >10, there was no zone of inhibition on the MRS control plate and these values were normalized to 1 for compution of the ratio. A dash represents no change in zone diameter between the two plates. Values in parenthesis represent inverse ratios for which an increase in resistance (smaller zone diameter) was observed on bile acid-containing plates. NG, no growth observed on bile acid-containing plates. For drug name abbreviations and concentrations, see Table 1, footnote b.