The prophylactic effect of heat- killed lactobacillus fermentum against pseudomonas aeruginosa infection in mice

Abstract EN

The protective effect of heat– killed Lactobacillus fermentum against Pseudomonas aeruginosa infection in Swiss mice with age of 5 weeks.

0.5 mg of heat – killed Lactobacillus fermentum was injected in intraperitoneally (I.P.) 5 days before challenge with 0.2 ml of viable P.

aeruginosa (10 8 cell / ml).

Animals were sacrificed by cervical dislocations after 12 h.

from challenge dose.

To follow bacterial growth in the peritoneal cavity of injected Mice , its contents were washed out with 5 ml of PBS .The number of colonies in 5 ml of harvested fluid was expressed as Log 10 CFU .

Bacterial growth in the Spleen was determined by spreading the organ homogenates.

Survival of mice after intraperitoneal (I.P.) infection with P.

aeruginosa was augmented in mice that had been pretreated I.P.

with L.

fermentum five days earlier.

Mice became resistant to infection with P.

aeruginosa after pretreatment with L.

fermentum .

Growth of P.

aeruginosa in the peritoneal cavity and spleen was markedly inhibited in L.

fermentum pretreated mice, whereas such inhibition of bacterial growth was not observed in control group (mice don’t treated with L.

Fermentum) the mean number of peritoneal cells in control mice was 3 x 106 CFU and 60% of these cells were macrophages.

It was suggested that macrophages activated by L.

fermentum were involved in the protection against P.

aeruginosa.