Isopropoxy Benzene Guanidine Ameliorates Streptococcus suis Infection In Vivo and In Vitro

Streptococcus suis, an encapsulated zoonotic pathogen, has been reported to cause a variety of infectious diseases, such as meningitis and streptococcal-toxic-shock-like syndrome. Increasing antimicrobial resistance has triggered the need for new treatments. In the present study, we found that isopropoxy benzene guanidine (IBG) significantly attenuated the effects caused byS. suisinfection, in vivo and in vitro, by killingS. suisand reducingS. suispathogenicity. Further studies showed that IBG disrupted the integrity ofS. suiscell membranes and increased the permeability ofS. suiscell membranes, leading to an imbalance in proton motive force and the accumulation of intracellular ATP. Meanwhile, IBG antagonized the hemolysis activity of suilysin and decreased the expression ofSlygene. In vivo, IBG improved the viability ofS. suisSS3-infected mice by reducing tissue bacterial load. In conclusion, IBG is a promising compound for the treatment ofS. suisinfections, given its antibacterial and anti-hemolysis activity.Keywords:Streptococcus suis;isopropoxy benzene guanidine;antibacterial;anti-hemolysis;suilysin