Evaluation of oxidative stress in foals with Rhodococcus equi infection-induced pneumonia for the judgment of therapeutic effect

Abstract

Forty-five foals with Rhodococcus equi infection and pneumonia symptoms were classified into a surviving group and a dead group. Using serum samples, the oxidative stress index (OSI) was determined at the first visit and the follow-up visit. The OSI of the surviving group was significantly lower at the follow-up than that at the first visit. No significant difference was observed between the OSI of the dead group at the first and follow-up visits. In the surviving group, treatment at the first visit mitigated inflammation and reduced OSI. However, in the dead group, poor response to the treatment provided at the first visit led to continued inflammation, and no change was observed the OSI.

Keywords: Rhodococcus equi; horse; oxidative stress; pneumonia.

Fig. 1.

Box-and-whisker plot of diacron-reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and oxidative stress index (OSI) in the surviving group. (a) d-ROMs in the surviving group, (b) BAP in the surviving group, (c) OSI in the surviving group. The d-ROMs value of the surviving group was significantly lower at the follow-up than at the first visit. The BAP value of the surviving group was significantly higher at the follow-up than at the first visit. The OSI of the surviving group was significantly lower at the follow-up than at the first visit (n=38, *: P<0.001).

Fig. 2.

Box-and-whisker plot of diacron-reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and oxidative stress index (OSI) in the dead group. (a) d-ROMs in the dead group, (b) BAP in the dead group, (c) OSI in the dead group. In the dead group, no significant differences were observed in the d-ROMs, BAP, and OSI values at the first visit and follow-up (n=7).