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 bactoagar at 37OC. In experiments with cell inactivation, vaccine strain of Y. pestis EV have been used, with concentration of bacterial suspension 109 microbial cells/ml.

Bacteria have been processed by radiation of red LED (λo = 650 nm, Δλ = 10 nm), power density have been varied at 1, 3 and 5 mW/cm2.

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

Time, 104 s

Time, 104 s

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)

P=0.2 mW

P=0.6 mW

P=1 mW

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)

Dose, J

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.