Intraperitoneal administration of leukotriene B4 (LTB4) and omega-guanidino caproic acid methane sulfonate (GCA) increased the survival of mice challenged with methicillin-resistant Staphylococcus aureus (MRSA).

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) very often complicate management of immunocompromised patients. We studied the effect of leukotriene B4 (LTB4) and epsilon-guanidino caproic acid methane sulfonate (GCA), on MRSA infection. Mice fed a 20% casein diet were intraperitoneally administered LTB4, GCA, or saline (control) daily for 30 days. On the 10th day of this treatment, mice were challenged with MRSA. The survival rate in the control group (20%) was significantly lower than the rates in the GCA (60%) and LTB4 (50%) groups, respectively (p < 0.05). There was a significant reduction of MRSA in the spleen and kidney of the survived mice in GCA group as against mice in the LTB4 and saline groups, indicating a better recovery in GCA group than the other groups. The results suggest that intraperitoneal administration of GCA and LTB4 may play a role in host defense mechanism during MRSA infections.