Generation of Protective Antibodies in Mice via Inactivated Whole-Cell Vaccine Targeting Multidrug-Resistant Escherichia coli

Background: The growing prevalence of multidrug-resistant (MDR) Escherichia coli poses a significant challenge for clinicians, often leading to treatment failures. Developing an effective vaccine could help address issues related to antibiotic resistance and therapeutic limitations. Objectives: This study aimed to evaluate the immune response elicited by a formaldehyde-inactivated MDR E. coli vaccine in a murine model. Methods: A total of fifteen Swiss albino mice were used. The experimental group received three intradermal doses of formaldehyde-inactivated MDR E. coli at 14-day intervals. Following immunization, mice were challenged intraperitoneally with live E. coli and monitored for 14 days. Blood was collected from the tail to measure serum antibody binding using ELISA. Results: All immunized mice (100%) survived the 14-day post-challenge period. ELISA results revealed a statistically significant increase (p < 0.001) in serum IgG levels both before and after the challenge in the immunized group. Conclusion: This study demonstrates that formaldehyde-inactivated MDR E. coli can stimulate the production of protective antibodies in mice, suggesting its potential as a vaccine candidate.