Core-Proteomics-Based Annotation of Antigenic Targets and Reverse-Vaccinology-Assisted Design of Ensemble Immunogen against the Emerging Nosocomial Infection-Causing Bacterium Elizabethkingia meningoseptica

Elizabethkingia meningoseptica is a ubiquitous Gram-negative emerging pathogen that causes hospital-acquired infection in both immunocompromised and immunocompetent patients. It is a multi-drug-resistant bacterium; therefore, an effective subunit immunogenic candidate is of great interest to encounter the pathogenesis of this pathogen. A protein-wide annotation of immunogenic targets was performed to fast-track the vaccine development against this pathogen, and structural-vaccinology-assisted epitopes were predicted. Among the total proteins, only three, A0A1T3FLU2, A0A1T3INK9, and A0A1V3U124, were shortlisted, which are the essential vaccine targets and were subjected to immune epitope mapping. The linkers EAAK, AAY, and GPGPG were used to link CTL, HTL, and B-cell epitopes and an adjuvant was also added at the N-terminal to design a multi-epitope immunogenic construct (MEIC). The computationally predicted physiochemical properties of the ensemble immunogen reported a highly antigenic nature and produced multiple interactions with immune receptors. In addition, the molecular dynamics simulation confirmed stable binding and good dynamic properties. Furthermore, the computationally modeled immune response proposed that the immunogen triggered a strong immune response after several doses at different intervals. Neutralization of the antigen was observed on the 3rd day of injection. Conclusively, the immunogenic construct produces protection against Elizabethkingia meningoseptica; however, further immunological testing is needed to unveil its real efficacy.

Elizabethkingia meningoseptica –An emerging infection: A case report

Elizabethkingia meningoseptica are Gram-negative rod bacteria that are commonly found in the environment. The bacteria have also been associated with nosocomial infections, having been isolated on contaminated medical equipment, especially in neonatal wards. Rapid diagnosis and early institution of appropriate therapy for prolonged period are essential for the management of such infections. Here, we report a case of bacteremia due to E. meningoseptica in a neonate who was presented with respiratory distress and seizure episodes. A diagnosis of bacterial meningitis was made based on clinical findings and examination of cerebrospinal fluid. The baby was treated with antibiotics and other supportive measures, that helped to improve the condition. During follow-up, the baby showed developmental delay with hydrocephalus. E. meningoseptica can cause severe infection, with high risk of mortality and neurological sequelae in neonates. Intensive care and multidisciplinary interventions are crucial for the case management. Awareness among clinicians along with correct diagnosis in microbiology laboratory is required to minimize the fatal outcome associated with this infection.