of Listeria monocytogenes planktonic and biofilm-associated cells
A. Adu-Gyamfi1 and S.T.Odonkor2
and Nuclear Agriculture Research Institute, Ghana Atomic Energy
Commission, P.O. Box LG 80, Legon, GHANA.
Research Centre, Radiological and Medical Sciences Research Institute,
Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, GHANA.
Academic Editor: Dr.
Listeria monocytogenes were formed on sterile glass
slides in a coincubation apparatus, using inoculated tryptic
soy broth, incubated at 37�C for 48 h. The planktonic and biofilm
cultures were subjected to incremental gamma radiation doses
(0, 0.5, 1.0, 1.5 , 2.0 kGy) from a Cobalt-60 source. The D10
values were calculated from the linear regression model for the
logarithm of the surviving fraction and irradiation dose. The survivors
and surviving fraction of planktonic and biofilm-associated cells
decreased with increased irradiation doses. The D10
value of L. monocytogenes planktonic cells (0.476KGy) was
higher than that of biofilm-associated cells (0.379KGy) indicating
biofilm cells were more sensitive to ionizing radiation than planktonic
cells. The antimicrobial efficacy of ionizing radiation is
therefore preserved or enhanced in the treatment of biofilm-associated