<P> Both the liver cholera vaccine and live typhoid vaccine can be made ineffective if given with ampicillin . Ampicillin is normally used to treat cholera and typhoid fever, lowering the immunological response that the body has to mount . </P> <P> Ampicillin is in the penicillin group of beta - lactam antibiotics and is part of the aminopenicillin family . It is roughly equivalent to amoxicillin in terms of activity . Ampicillin is able to penetrate Gram - positive and some Gram - negative bacteria . It differs from penicillin G, or benzylpenicillin, only by the presence of an amino group . That amino group, present on both ampicillin and amoxicillin, helps them enter the pores of the outer membrane of Gram - negative bacteria, such as E. coli, Proteus mirabilis, Salmonella enterica, and Shigella). </P> <P> Ampicillin acts as an irreversible inhibitor of the enzyme transpeptidase, which is needed by bacteria to make the cell wall . It inhibits the third and final stage of bacterial cell wall synthesis in binary fission, which ultimately leads to cell lysis; therefore, ampicillin is usually bacteriolytic . </P> <P> Ampicillin is well - absorbed from the GI tract (though food reduces its absorption), and reaches peak concentrations in one to two hours. The bioavailability is around 62% for parenteral routes . Unlike other penicillins, which usually have bind 60--90% to plasma proteins, ampicillin binds to only 15--20% . </P>

Which cellular component in the bacterial cell is targeted by ampicillin