Aim: The present study aimed to determine the antibiotic reaction and adhesion
pattern of antimicrobial homo-fermenting LAB strains in the
fermenting slurries of
kunu-zaki, Nigeria.
Background: Lactic acid bacteria are usually found in
decomposing plants and
lactic products. Lactic acid is the major metabolic
end-product of the carbohydrate
fermentation. LAB is a large group of fermentative, anaerobe
aero-tolerant
microorganisms that are usually present in the gut of humans
and other animals,
raw vegetables, meat and meat products, and cereal.
Study Design: Samples were obtained directly from the
72-hour fermenting mash
of the kun-uzaki made from each cereal type. The Pour plate
technique was used
to isolate the organisms. The pure colonies isolates were
examined according to
their colony morphology, catalase reaction and gram
reaction. Inhibition of
indicator lawn used ≥10mm inhibition as antibiotic
susceptible. Adhesion was
measured by staining and quantifying grains of
Digitariaexilis (acha), Sorghum
bicolour (sorghum) and Pennisetum americanum (millet) in
composite and non
composite proportions. LAB isolates were obtained on MRS
agar. Homo
fermenting isolates were identified at species level using
the API 50 CHL test kit.
Antibiotic sensitivity testing on the identified isolates
followed the modified
standard Kirby-Bauer procedure on MRS agar (pH 7.4) using
the disc diffusion
technique with selected antibiotics. For quality control of
the antibiotics, sensitive
reference strains S. aureus ATCC 25923 and E. coli ATCC
25922 obtained from
the Nigeria Institute of Medical Research were used.
Adhesion properties were
determined by differential staining of the bacterial cells
that bound to intestinal
epithelial cells as observed under light and phase contrast
microscopy.
Results: Antimicrobial substances produced by the
eight LAB isolates inhibited
the growth of four selected human pathogens in vitro. All
eight LAB isolates were
resistant to amoxicillin, gentamycin and ciprofloxacin. L.
plantarum126, L.
paracasei sub sp paracasei339 and Pediococcus damnosus32
were resistant to
erythromycin whilst all others were susceptible. L.
plantarum126 and L.
paracaseisubspparacasei339 were resistant to all antibiotics
tested. All LAB
isolates demonstrated high in-vitro intestinal epithelial
cell adhesion potential. The
result of this study documents findings on the antibiotic
resistance pattern of these
eight homo-fermenting lactic acid bacteria present in ready
to drink kunu-zaki. If
these homo-fermenting strains are to be used in kunu-zaki as
starter cultures, it is
important that they should be further carefully examined for
inability to transfer
antibiotic resistance genes to food pathogens.
Conclusion: When used in conjunction with these
antibiotic treatments, kunuzaki
may not have an impact on the antibacterial activity of LAB.
To ensure that these
LAB strains cannot pass antibiotic resistance genes to food
pathogens, they must
be thoroughly screened if they are to be used as kunu-zaki
starter cultures.
Author (s) Details
S. O. Oluwajoba
Department of Microbiology, Federal University of
Technology, Akure, Nigeria and Department of Biological Science, Yaba College
of Technology, Yaba, Lagos, Nigeria.
F. A. Akinyosoye
Department of Microbiology, Federal University of
Technology, Akure, Nigeria.
V. O. Oyetayo
Please see the link - https://doi.org/10.9734/bpi/rpmab/v3/211
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