case_images: PMC11825202_01
case_images: Single-shot fast spin echo T2 weighted magnetic resonance imaging showing a collection in the anterior abdominal wall located at the left paramedian region, which slightly imprints and displaces the left hepatic lobe (a). The content appears mildly and heterogeneously hyperintense on fluid-sensitive sequences, indicating a predominantly fluid component with proteinaceous content. The walls appear moderately thickened. The described finding appears compatible with an abscess collection. Moreover, there is a slight edema and inhomogeneity present in the visceral peritoneal fat (b).
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case_images: Magnetic resonance imaging (MRI) contrast examination showed an increased swelling with irregular and intense thickening and progressive enhancement of the walls with uneven content (Figure 1).
case_images: Gram staining performed on drainage fluids at 100X magnification. The staining highlights the filamentous and branched cells of N. kroppenstedtii (a). N. kroppenstedtii growing on CNA agar. Note the different morphology after 24 h (on the left), and prolonged incubation (on the right) (b).
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case_images: fig2
case_images: Microbiology and Virology, cultured in brain heart infusion (BHI) broth and incubated at 37 C. Meanwhile, the staining of the two samples resulted in Gram-positive bacilli with a branching filamentous morphology that resembled actinomycetes (Figure 2(a)). After the incubation period, we observed the growth of greyish colonies only on Columbia CNA agar which became yellowish after 4-5 days (Figure 2(b)), for both the fluids.
case_images: N. kroppenstedtii spectrum generated on MALDI-TOF MS.
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case_images: Additionally, the spectra underwent baseline correction and were adjusted to the total positive ion current (Figure 3).
case_images: Axial CT portal venous phase section shows a large discontinuity at the level of the anterior abdominal wall, as a result of surgical drainage of the previously noted collection. The postoperative CT revealed a good surgical cleaning of the site, with no further collections observed and no postoperative complications identified.
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case_images: fig4
case_images: A total body CT scan was performed before dismission, showing successful surgical site debridement with no residual collections (Figure 4).