Hi Sony

If you have access to both test them against E coli then decide which one you should use; if you do not have both then test what you have and make as a control.

Hope this helps   

Hello Sony

You can use Ciprofloxacin as it is a broad spectrum antibiotic which is active against both gram negative and gram positive bacteria.

If you are using E. coli susceptible strain (ATCC25922), It's better to use amoxicilin. If not, may ciprofloxacin wich are more active than genta