Effect of Teicoplanin and G-CSF on Survival in Experimental MRSA Pneumonia in Neutropenic Mice

Aim: To evaluate the effects of Teicoplanin and/or Granulocyte-Colony Stimulating Factor (G-CSF) on survival in an experimental model of MRSA pneumonia.

Material And Method: Seventy five Swiss Albino mice weighing 35 gr (32-43) were used. 50 microl of clinical isolate of MRSA (3 x 10(8) CFU/ml in saline solution) was administered by tracheal puncture to neutropenic mice. Neutropenia was achieved by using Cyclophosphamide 200 mg per kg intraperitoneally. The groups were consisted of tracheal puncture control in neutropenic mice (group 1) (n = 15), pneumonia in neutropenic mice (group II) (n = 15), Teicoplanin therapy for pneumonia in neutropenic mice (group III) (n = 15), G-CSF therapy for pneumonia in neutropenic mice (group IV) (n = 15), Teicoplanin and G-CSF combined therapy for pneumonia in neutropenic mice (group V) (n = 15). Differences in the survival rates within 72 hours among the groups, microbiological analysis of various tissue samples were accomplished and white blood cell counts were obtained. Kaplan-Meier statistics was used for survival analysis. Subgroup comparisons were done by using Breslow statistics.

Results: Teicoplanin therapy increased the survival rate (p = 0.0001) whereas G-CSF therapy did not in comparison to other groups. Teicoplanin and G-CSF combination therapy improved survival rate when compared with groups II, III, IV (p = 0.0001, p = 0.003, p = 0.0001, respectively).

Conclusion: Teicoplanin and G-CSF combination therapy seems effective in reducing mortality rates in MRSA pneumonia in an experimental setting. Further animal and clinical studies must be done to achieve success in the treatment of nosocomial MRSA pneumonia.