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Formation of
biofilm by strains of Listeria monocytogenes isolated
from soft cheese 'wara' and its processing environment
V.
O. Adetunji1* and G. O. Adegoke2
1Department of Veterinary Public Health and Preventive
Medicine, University of Ibadan, Ibadan, Nigeria.
2Department of Food Technology, University of Ibadan, Ibadan,
Nigeria.
*Corresponding author: E-mail:
vadetunji@gmail.com.
Accepted 10 July, 2008 |
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Quantification of biofilm formation by 40
Listeria monocytogenes strains from wara soft cheese
and its processing environment was assessed on glass vials
surfaces. Attachement to glass surface was quantified using
a crystal violet binding assay. All the 40 strains produced
biofilms after 48 and 72 h incubation at 37oC. No
biofilms were formed at 24 h incubation but biofilm
formation increased with incubation period in 20 out of the
40 strains. R2 values obtained were 0.0166 and
0.1193 respectively for biofilm formation between 24 and 48
h and 24 and 72 h incubation periods, respectively (P-values
of < 0.05*). L. monocytogenes strains isolated from
wara cheese were generally sensitive to augmentin,
streptomycin, claforan, erythromycin, gentamycin, septrin,
tarivid, and rocephine and were highly resistant to
nitrofuran, fortum, zinnat, and tetracycline. The
enhancement of biofilm formation in L. monocytogenes
strains from ‘wara’ in this study suggests a relationship
with pathogenicity in foodborne isolates. The transfer of
antibiotic resistant L. monocytogenes to human via
the food chain is a significant health concern.
Key words:
biofilm, Listeria monocytogenes, ‘wara’,
antibiotic sensitivity, incubation. |
