Antibiotic resistance proWle and transferability of
resistances. Bacteria may bear transferable resistances. Some
enterococcal strains have shown a resistance to vancomycin
and a capacity to transfer this kind of resistance to other bacteria
species. The SCAN has adopted an opinion on this matter
(European Commission, 2001a,b), which was updated
(European Commission, 2003). In 2005, a new opinion of
FEEDAP Panel of the EFSA has anew updated the criteria
used for the assessment of bacteria for resistance to antibiotics
of human or veterinary importance (EFSA, 2005a). The
aim of this opinion is to provide guidance for developing
studies to show the potential of each bacterial strain (and not
yeast) to bear resistances and to transfer them. The basis of
such evaluation starts with the determination in vitro antibacterial
activity [minimum inhibitory concentration (MIC)]
for a relevant range of antibiotics of human or veterinary
importance. Although the detection of the MIC above the
breakpoint levels identiWed for one or more antimicrobials
requires further investigations to make the distinction
between acquired and intrinsic resistance, the microbiological
breakpoints categorising bacteria as resistant are expressed in
Table 1. When a bacterial strain is known to be resistant to a
speciWc antibiotic, while others species normally are susceptible
to this antibiotic, the applicant should evaluate the reason
for such resistance. If an acquired resistance may be transferred
or if known exogenous resistance genes are present,
the probiotic strain is not considered as suitable for use as
feed additive.