Mycobaterium fortuitum disseminated infection in an immunocompetent patient without predisposing factors

A case of complete Melkersson-Rosenthal syndrome: Possibly associated with Mycolicibacterium fortuitum from odontogenic origin

Melkersson-Rosenthal syndrome (MRS) is a neuromucocutaneous disease of unknown pathogenesis. With this communication, we describe a case of a 26-year-old woman with complete MRS in whom Mycolicibacterium fortuitum was detected in the swelling lip biopsy by next- generation sequencing. The patient's symptoms were slightly improved after intralesional corticosteroid injection combined with broad-spectrum antibiotics, while they were significantly improved after further treatment of dental caries and removal of the residual root. This case provides insight into the possible microbial infection pathogenesis of MRS, and M. fortuitum was speculated to be related to granulomatous and neuronal disorders, most probably from odontogenic origin.

M. fortuitum-induced CNS-pathology: Deciphering the role of canonical Wnt signaling, blood brain barrier components and cytokines

Molecular underpinning of mycobacteria-induced CNS-pathology is not well understood. In the present study, zebrafish were infected with Mycobacterium fortuitum and the prognosis of CNS-pathogenesis studied. We observed M. fortuitum triggers extensive brain-pathology. Evans blue extravasation demonstrated compromised blood-brain barrier (BBB) integrity. Further, decreased expression in tight-junction (TJ) and adherens junction complex (AJC) genes were noted in infected brain. Wnt-signaling has emerged as a major player in host-mycobacterial immunity but its involvement/role in brain-infection is not well studied. Sustained expression of wnt2, wnt3a, fzd5, lrp5/6 and β-catenin, with concordant decline in degradation complex components axin, gsk3β and β-catenin regulator capn2a were observed. The surge in ifng1 and tnfa expression preceding il10 and il4 suggested cytokine-interplay critical in M. fortuitum-induced brain-pathology. Therefore, we suggest adult zebrafish as a viable model for studying CNS-pathology and using the same, conclude that M. fortuitum infection is associated with repressed TJ-AJC gene expression and compromised BBB permeability. Our results implicate Wnt/β-catenin pathway in M. fortuitum-induced CNS-pathology wherein Th1-type signals facilitate bacterial clearance and Th2-type signals prevent the disease sequel.