The selected lactobacilli strains were susceptible to
all the analyzed antimicrobial agents (including tetracycline,
erythromycin, clindamycin, ampicillin, and
aminoglycosides) with the exception of vancomycin, for
which an intrinsic resistance was observed. The chloramphenicol
MIC for MRS55 and M1743 strains was
only one dilution higher (8 μg/mL) than the microbiological
breakpoint defined by the EFSA (4 μg/mL),
which is within the normal acceptable variation around
the means (EFSA, 2012).