Daftar Isi:
  • Salmonella typhi is a cause of typhoid fever. The  major problem in the therapy is drug resistancy. PhoP-PhoQ  two-component  system  is  a  regulator  of  many  virulent  factors  of  Salmonella  typhi  used in this research as a potential target of developing new antibacterial agents. The goal of this research is to search new antibacterial agents against Salmonella typhi. The research procedure involved isolating the DNA,  optimating  phoQ  gene  amplification,  and  cloning  the  gene.  These  steps  were  used  as  a  part of a novel screening system for searching new antibacterial agents against Salmonella typhi. S. typhi genome was isolated by using Wizard Isolation Kit, and then PCR were done by using PhoQFWD and PhoQREV as  primers.  Afterwards,  phoQ  was  cloned  by  using  pGEM-T  easy  vector.  The  result  was  grown  in  LB agar  medium  containing  ampicillin,  IPTG  and  X-gal,  and  plasmid  with  DNA  insert  was characterized with fast lysis method. The result of DNA isolation is the total cell DNA of Salmonella typhi. PCR was performed  in  30  cycles.  Denaturation  was  at  94oC  for  a  minute,  annealing  at  53oC  for  a  minute,  and extension  at  72oC  for  2  minutes.  The  result  showed  a  band  between  1000  and  1500  bp,  close  to  the expected size 1464 bp. The cloning produced 37 white colonies and 11 blue colonies. After fast lysis, the colonies number 9, 18, 24 and 34 displayed a band with a size larger than that of the empty pGEM-T easy vector and were expected to have been inserted with DNA target.  Keywords: Salmonella typhi, PhoP-PhoQ two-component system, DNA isolation, PCR, cloning.