PMC10013466_01
1A) Clinical picture. The right mandible showed edema, hyperpigmentation, ulcer, and seropurulent secretion; 1B) Histopathology [5X, hematoxylin-eosin (H&E) stain]. Lower magnification exhibits epidermal hyperplasia, fistulous tract, cutaneous ulcer, vascular damage, and inflammatory infiltrate dermis; 1C) (40X, PAS stain) High magnification showed inflammatory infiltrate composed of histiocytes, plasma cells, lymphocytes, and polymorphonuclear infiltrate with extravasated erythrocytes in dermis; 1D) (40X plus close-up H&E stain) Exhibits a trypomastigote in the deep dermis; 1E) [100X, Ziehl-Neelsen (ZN) stain] In dermis, observe multiple amastigotes that display nuclei and kinetoplasts; 1F) (100X, ZN stain) In fat tissue, observe intracellular bacteria clusters, ZN negative; 1G) (100x, Gram stain) A direct examination from the MacConkey culture obtained from tissue sample reveals gram-negative bacilli.
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The dermatosis comprised an area of 3x4 cm and exuded a slightly seropurulent secretion (Figure 1A). Tissue slices (Figure 1B) exhibited an inflammatory infiltrate composed of histiocytes, plasma cells, lymphocytes, and polymorphonuclear located in the dermis and subcutaneous tissue (Figure 1C). Surprisingly, parasites (amastigotes and trypomastigotes), as well as intracellular bacteria, were presented in the tissue samples (Figures 1D, 1E, and 1F). The former corresponded to a Gram-negative bacillus, Ziehl-Neelsen negative, and catalase-negative, identified by PCR and sequencing as Bacillus velenzensis (Figure 1G), and the second was identified as Corynebacterium sp.
The phylogenetic tree showed reference sequences from DTU I to DTU V, and the sequence from the present case belongs to DTU II group, and is located near to the sequence obtained from South America (Brazil and Argentina).
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Furthermore, Bayesian phylogenetic analysis (Figure 2) supported the grouping of the sequence obtained inside T. cruzi DTUs and showed high posterior probability values (1.00) for DTU II.