CULTURAL AND MORPHOLOGICAL
PROPERTIES OF THE VACCINE STRAIN OF
BACTERIA Y. PESTIS EV NIIEG AFTER
PHOTODYNAMIC INACTIVATION
Onega Ulianova, Saratov State Agrarian University, RUSSIA
Sergey Ulyanov, Saratov State University, RUSSIA
Inactivation of bacteria vaccine strain of the plague microbe Y. pestis EV NIIÈG have
been carried out by photodynamic method (PDT).
Cells of Y. pestis EV NIIÈG after the PDT and intact cells have been cultivated on
O
bactoagar at 37 C. In experiments with cell inactivation, vaccine strain of Y. pestis EV
9
have been used, with concentration of bacterial suspension 10 microbial cells/ml.
Bacteria have been processed by radiation of red LED (λo = 650 nm, Δλ = 10 nm),
2
power density have been varied at 1, 3 and 5 mW/cm .
Methylene blue has been added to bacterial suspension in very small concentrations of
0.0005 %, 0.05% and 0.005 %.
Inactivation of suspensions have been carried out during 5-360 min. The results of
experiments are presented in Figures below.
Time, min
Time, min
Time, min
Changing of number of colonies-generated cells (KOE) Y. pestis EV NIEG (Осд) after photoinactivation (1 мW/cm2):
exposition with methylene blue with concentration 0,0005 % (а); 0,005 % (b); 0,05 % (c)
during 5–60 min; Кк – culture control ; Кмс – culture control with methylene blue ;
Ксд – culture of illumination by light emitting diodes
Time, min
Time, min
Time, min
Changing of number of colonies-generated cells (KOE) Y. pestis EV NIEG (Осд) after photoinactivation (3 мW/cm2):
exposition with methylene blue with concentration 0,0005 % (а); 0,005 % (b); 0,05 % (c)
during 5–60 min; Кк – culture control ; Кмс – culture control with methylene blue ;
Ксд – culture of illumination by light emitting diodes
Time, min
Time, min
Time, min
Changing of number of colonies-generated cells (KOE) Y. pestis EV NIEG (Осд) after photoinactivation (5 мW/cm2):
exposition with methylene blue with concentration 0,0005 % (а); 0,005 % (b); 0,05 % (c)
during 5–60 min; Кк – culture control ; Кмс – culture control with methylene blue ;
Ксд – culture of illumination by light emitting diodes
P=0.2 mW
Time, 104 s
P=0.6 mW
Time, 104 s
P=1 mW
Time, 104 s
Dependence of parameter of growth of cells of Y. pestis EV (grow) on
time of photoinactivations of bacteria and concentration of methylene
blue 0,05 % (а); 0,005 % (б); 0,0005 % (в)
Dose, J
Dependence of parameter of growth of cells of
Y. pestis EV (grow) on dose of (J) and
concentration of methylene blue 0,05 % (а);
0,005 % (б); 0,0005 % (в)
Changes of number of colonies-generated cells Y. pestis EV NIEG after photoinactivation
I = 1мВт/см2, concentration of methylene blue is 0,005 %
Changes of number of colonies-generated cells Y. pestis EV NIEG after photoinactivation
I = 1мВт/см2, concentration of methylene blue is 0,005 %
Changes of number of colonies-generated cells Y. pestis EV NIEG after photoinactivation
I = 1мВт/см2, concentration of methylene blue is 0,005 %
Changes of number of colonies-generated cells Y. pestis EV NIEG after photoinactivation
I = 1мВт/см2, concentration of methylene blue is 0,005 %
Resume:
It is extremely important to note that both activation and inhibition of cell
growth does not depend on the dose only , but also on the mode of
exposure.
When defining the dependence of light-induced effects in bacterial
suspensions of photosensitizer concentration it was quite evident that the
concentration of singlet oxygen produced in a bacterial suspension and
interacts with cells depends not only on the intensity of light, but also on
the initial concentration of photosensitizer.
Thus, the product of dose and concentration is an important parameter in
determining the processes of interaction of light with bacterial cells.
Dependence of parameters of cell growth of Y. pestis EV (during the
process of photoinactivation) on product of exposure to concentration of
methylene blue is characterized by a significant dispersion of the received
data.