Title : An unusual case of multidrug-resistant klebsiella pneumoniae and vancomycin-resistant enterococcus faecium skin and soft tissue infection in an immunocompromised host
Abstract:
Skin and soft tissue infections (SSTI) represent an uncommon source of infection (<10%) in patients with persistent or recurring fever and neutropenia.1-3 Worldwide, the prevalence of immunocompromised hosts is increasing even as the incidence of gram-negative and of multidrug-resistant (MDR) SSTI are also increasing, exacerbating existing challenges in treating infection in neutropenic patients.
A 43-year-old male with B-cell acute lymphoblastic leukemia (B-ALL) (on treatment with R-hyper-CVAD [rituximab, cyclophosphamide, vincristine, doxorubicin, dexamethasone] with intrathecal cytarabine) and schizophrenia (on multiple psychiatric medications) presented with neutropenic fever. He had a history of three MDR Klebsiella pneumoniae bloodstream infections within the last six months alone. Indeed, his blood cultures were positive for Klebsiella pneumoniae again and meropenem was started, with therapeutic drug monitoring used to optimize dosing. The source, however, remained unclear. CT of the chest, abdomen, and pelvis was unremarkable. An echocardiogram performed to evaluate for endocarditis revealed neither vegetations nor valvular changes. He continued to be febrile and vancomycin therapy was added empirically.
Then, the left gluteal lesion that had been present on admission ruptured and began draining purulent material. The abscess itself had an unusual appearance with dark purple coloring, initially suggestive of ecthyma gangrenosum. Bedside incision and drainage was performed. However, the surrounding erythema and induration continued to progress even after presumed source control. Empiric antifungal therapy was considered but deferred given the potential interactions with both his chemotherapy and antipsychotic medications. Vancomycin was switched to daptomycin, and he was taken to the operating room for surgical exploration of the abscess. Intraoperative deep tissue cultures ultimately grew both MDR Klebsiella pneumoniae and vancomycin-resistant Enterococcus faecium. Both meropenem and daptomycin were continued and he improved clinically. For the management of his B-ALL, in order to avoid future neutropenia, he was switched from chemotherapy to bispecific T-cell engager therapy.
We present a case of a mixed MDR SSTI in an immunocompromised host, with SSTI as a presumed source of recurrent gram-negative bloodstream infection. Both Klebsiella pneumoniae and Enterococcus faecium are uncommon culprits in SSTI. Broad-spectrum antibiotics, source control, and species identification were critical in managing infection in an already vulnerable host.
