Comparative Study of 48-Hour Survival in Female Sprague Dawley Rats in Oestrus After Sepsis Induction by CLP

Abstract

Sepsis remains a major cause of mortality worldwide, driven by an uncontrolled inflammatory response to infection that compromises organ function. This study aimed to evaluate the effects of the probiotic strain Alcaligenes faecalis A12C on 48-hour survival and physiological outcomes in a rat model of peritonitis-induced sepsis. Fourteen female Sprague-Dawley rats in oestrus were randomly assigned to two groups: a control group (CSI) receiving only water and a treatment group (PSI) receiving A. faecalis A12C (6 × 10⁸ CFU/mL) in drinking water over 30 days. Sepsis was induced by caecal ligation and puncture (CLP), and survival was assessed for 48 hours post-surgery. Microbiological analyses confirmed successful gut colonization by A. faecalis A12C in the PSI group. Haematological and biochemical parameters remained within physiological reference ranges, indicating no adverse effects from the probiotic. However, creatinine levels were significantly lower in the PSI group, suggesting improved renal function. Additionally, visible clinical signs such as plantar cyanosis and ruffled fur were significantly reduced in treated animals. Although the difference in survival between groups did not reach statistical significance, the PSI group showed a notably higher survival rate (85.71%) compared to the CSI group (42.85%). This finding, combined with reduced clinical deterioration and improved renal biomarker profiles, supports the hypothesis of a beneficial physiological effect mediated by the probiotic. Furthermore, the study aligns with prior evidence that female animals exhibit enhanced immune regulation and better outcomes in sepsis models, attributed in part to the immunoprotected effects of oestrogens. In summary, this study demonstrates that A. faecalis A12C can colonize the gut, modulate the host immune response, and improve clinical outcomes following sepsis induction without compromising physiological balance. These findings suggest that this strain, possibly through its production of β-1,3-glucan (curdlan), may serve as a promising candidate for future research on probiotic-based interventions in septic conditions.