The effector protein BteA induces host cell death by disruption of calcium homeostasis.

is the causative agent of whooping cough in humans, a disease that has recently experienced a resurgence. In contrast, infects the respiratory tract of various mammalian species, causing a range of symptoms from asymptomatic chronic carriage to acute illness. Both pathogens utilize type III secretion system (T3SS) to deliver the effector protein BteA into host cells.

Low-molecular weight chitosan enhances antibacterial effect of antibiotics and permeabilizes cytoplasmic membrane of Staphylococcus epidermidis biofilm cells.

This study evaluated the effect of low-molecular weight chitosan on Staphylococcus epidermidis, a common colonizer of joint implants and other prosthetic devices. We have also attempted to elucidate its mechanism of action. Chitosan was found to be effective against both the planktonic and biofilm cells (MIC 35-40 mg/L; MBIC 40-150 mg/L), in contrast to the antibiotics erythromycin and tetracycline with no antibiofilm activity (MBIC not found).