The main goal for scientific groups is the selection and identification of suitable inhibitory compounds against pathogenic bacterial protein tyrosine phosphatases (PTPs) involved in the infection process, such as PTPA and PTPB from Staphylococcus aureus and Mycobacterium tuberculosis; SptP from Salmonella typhimurium; YopH from Yersinia spp. Here, PTPA is linked to infection.