Abstract:
Bacteriophages are known to be the most abundant entity in the universe. They
infect bacteria and replicate inside bacterial cells either by lytic or lysogenic cycle.
Bacteriophages have been employed for many applications i.e. for transfer of
gene/protein vaccines, an alternative to antibiotics, screening of peptides/proteins,
identification of pathogens etc. They also have an important role in controlling biofilm,
an aggregation of microbial cells that are adhered to inert/biological surface or with each
other. Biofilms are resistant to antibiotics and other disinfectants so they a play major
role in the spread of disease, so an alternative should be find out to control biofilm
formation. Amongst biofilm forming bacteria, Salmonella typhi is gram negative, rod
shaped bacterium that is involved in spread of typhoid fever. Due to poor administrative
measures of antibiotics, this bacterium has developed resistant towards 3rd generation
antibiotics. This study aimed to isolate bacteriophage against Salmonella typhi and to
control biofilm formation. Bacteriophages were isolated from sewage water against
clinical bacterial strains and characterization of isolated phage showed it to be stable at
long temperature range (37-65 ºC) and pH range (5-11) with adsorption rate increased by
presence of divalent metal ions. The burst size of bacteriophage is 300 virions per cell
with 24 minutes latent time period. The isolated phage reduced bacterial population to 2
folds in planktonic culture and 2.2 folds in the biofilm. In conclusion our findings suggest
that waste water is a good source for finding bacteriophages against newly emerging
antibiotic resistant bacteria Salmonella typhi. Phages can be used to control bacteria both
in planktonic forms, as well as in biofilms. In conclusion our findings suggest that waste
water is a good source for finding bacteriophages against newly emerging antibiotic
resistant bacteria Salmonella typhi. Phages can be used to control bacteria both in
planktonic forms, as well as in biofilms
