摘要
There is growing interest in re-evaluation of older antibiotics with the wide spread of pathogen resistance, especially gram negative bacteria, which impair treatment of some infections. In contrast various studies have reported that some antibiotics have efficacy in clearing resistant bacterial infections. On account of that it was interesting to evaluate the efficacy of erythromycin, chloramphenicol and/or tenoxicam in curing and/or relieving wound infection of highly resistant Escherichia coli and investigate the possible mechanisms beyond their antibacterial activity. This was achieved through evaluating highly resistant E. coli strains in vitro using agar dilution and in vivo rat models of E. coli infected wound and acute inflammation by carrageenin, where possible mechanisms were evaluated through measuring immunological mediators and histopathological examination. This study revealed that in vivo, erythromycin alone or in combination with tenoxicam significantly improved the healing of infected skin wounds with E. coli irresspective of resistancy in vitro. In addition to the improvement of immunological mediators involved in inflammatory reaction, oxidative stress and in cytokines expression as response to the bacterial infection in vivo. On the other hand chloramphenicol neither alone nor in combination with tenoxicam, achieved any significant effect. Tenoxicam didn’t show antimicrobial activity alone nor in combination with tested antibiotics in vitro, but it has shown synergestic activity in combination with tested antibiotics in vivo. Thus we concluded that immunomodulatory activity of erythromycin through anti-inflammatory and antioxidant effects was the possible mechanisms by which this antibiotic had healed infection with resistant E. coli in vivo, despite its resistancy to this antibiotic in vitro.
There is growing interest in re-evaluation of older antibiotics with the wide spread of pathogen resistance, especially gram negative bacteria, which impair treatment of some infections. In contrast various studies have reported that some antibiotics have efficacy in clearing resistant bacterial infections. On account of that it was interesting to evaluate the efficacy of erythromycin, chloramphenicol and/or tenoxicam in curing and/or relieving wound infection of highly resistant Escherichia coli and investigate the possible mechanisms beyond their antibacterial activity. This was achieved through evaluating highly resistant E. coli strains in vitro using agar dilution and in vivo rat models of E. coli infected wound and acute inflammation by carrageenin, where possible mechanisms were evaluated through measuring immunological mediators and histopathological examination. This study revealed that in vivo, erythromycin alone or in combination with tenoxicam significantly improved the healing of infected skin wounds with E. coli irresspective of resistancy in vitro. In addition to the improvement of immunological mediators involved in inflammatory reaction, oxidative stress and in cytokines expression as response to the bacterial infection in vivo. On the other hand chloramphenicol neither alone nor in combination with tenoxicam, achieved any significant effect. Tenoxicam didn’t show antimicrobial activity alone nor in combination with tested antibiotics in vitro, but it has shown synergestic activity in combination with tested antibiotics in vivo. Thus we concluded that immunomodulatory activity of erythromycin through anti-inflammatory and antioxidant effects was the possible mechanisms by which this antibiotic had healed infection with resistant E. coli in vivo, despite its resistancy to this antibiotic in vitro.
