In vitro inhibition activity of nisin A, nisin Z, pediocin PA-1 and antibiotics against common intestinal bacteria.
OBJECTIVE
To evaluate the sensitivity of 21 common intestinal bacteria to six antibiotics and three broad-spectrum bacteriocins (nisins Z and A and pediocin PA-1).


RESULTS
Neutralized cell-free culture supernatants containing active bacteriocins, and antibiotics were tested with the agar diffusion test and the disc-diffusion method, respectively. The tested intestinal strains showed high sensitivity to most antibiotics except for streptomycin and oxacillin. Nisins A and Z (8 mug per well) had similar activity spectra and inhibited all Gram-positive intestinal bacteria at different levels (except Streptococcus salivarius), with bifidobacteria (except Bifidobacterium breve and Bif. catenulatum), Collinsella aerofaciens and Eubacterium biforme being the most sensitive strains, but they were not active against Gram-negative bacteria. Surprisingly, none of the tested strains were inhibited by pediocin PA-1 (16 mug per well).


CONCLUSIONS
Pediocin PA-1 which is very active against Listeria spp. and other food pathogens did not inhibit major intestinal species in the human intestine in contrast to both nisins A and Z.


CONCLUSIONS
Our data suggest that pediocin PA-1 has potential to inhibit Listeria within the intestinal microbiota without altering commensal bacteria.
Le Blay
G
G
Laboratory of Food Biotechnology, Institute of Food Science and Nutrition, ETH Zurich, Zurich, Switzerland. gwenaelle.leblay@ilw.agrl.ethz.ch
Lacroix
C
C
Zihler
A
A
Fliss
I
I
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology*; D041981:Gastrointestinal Tract / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D007778:Lactobacillus / Q000187:drug effects; D008089:Listeria monocytogenes / Q000187:drug effects; D009561:Nisin / Q000031:analogs & derivatives* / Q000494:pharmacology; D000070017:Pediocins
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D000070017:Pediocins; C074288:pediocin PA-1; D009561:Nisin; C102526:nisin A; C071364:nisin Z