Pneumonia and Bacteremia Due to Kytococcus schroeteri

Abstract

Kytococcus schroeteri, a saprophyte of the human skin, may cause serious infections in the immunocompromised host. Here, we describe a case of pneumonia and bacteremia due to Kytococcus schroeteri in an immunocompromised patient, successfully treated with linezolid and trimethoprim-sulfamethoxazole. CASE REPORTA 43-year-old woman diagnosed with acute myeloid leukemia (AML) received induction therapy with daunorubicin and cytarabin with poor response and was given a new induction therapy with fludara, cytarabin, and idarubicin. She was also treated with flucloxacillin and ciprofloxacin due to a breast abscess. Ten days later, the patient was readmitted to hospital because of neutropenic fever. Chest X-ray showed a small infiltrate in the right lung, and antibiotic therapy with piperacillin-tazobactam was initiated. A chest computed tomography (CT) scan performed 4 days later showed three small, dense infiltrates in the middle and lower lobe in the right lung. Bronchoscopy with bronchoalveolar lavage (BAL) was performed, and the patient was treated with voriconazole, which later was switched to liposomal amphotericin B when fungal cultures of BAL fluid and galactomannan antigen were negative. Blood cultures, taken the day after bronchoscopy was performed, showed growth of a Kytococcus species in one aerobic blood culture vial out of a total of four blood culture vials, two aerobic and two anaerobic. Susceptibility testing by Etest showed that the strain had low MIC values for vancomycin, meropenem, linezolid, and trimethoprim-sulfamethoxazole. Despite concerns regarding the clinical significance of the isolate, as it was only recovered in one blood culture vial, the patient was treated with vancomycin, and piperacillintazobactam was switched to meropenem. The BAL fluid culture yielded a pure growth of 10 5 CFU/ml of the same Kytococcus species. The isolate was later identified, using sequencing, as Kytococcus schroeteri. The patient continued to deteriorate, and a new chest CT scan showed large, dense infiltrates in both lungs with necrosis in the middle lobe. Due to therapeutic failure and to reach better antibiotic concentrations in the lungs, vancomycin was switched to linezolid, and later, trimethoprim-sulfamethoxazole was added when the patient continued to deteriorate. Finally, 19 days after the BAL was performed, the leucopenia resolved and the patient improved. She was discharged with long-term treatment with trimethoprimsulfamethoxazole, and 4 months later, allogeneic stem cell transplantation was successfully performed.Blood samples were cultured using the BacT/Alert 3D (bioMérieux, Inc., Durham, NC) automated blood culture system. After 48 h of incubation, one aerobic blood culture vial signaled positive. Gram staining revealed Gram-positive cocci occurring in pairs and in tetrads. Broth from the aerobic bottle was subcultured onto blood and CLED (cystine-lactose-electrolyte-deficient) agar plates incubated in air, chocolate agar plates incubated in 5% CO 2 , and blood agar plates incubated in an anaero...

Kytococcus schroeteriBacteremia in a Patient with Hairy Cell Leukemia: A Case Report and Review of the Literature

“…We are not sure this would have changed the outcome in our patient due to the degree of overwhelming septic shock and multiorgan dysfunction; however, sensitivity testing may have impacted our treatment choices in this patient. Other cases outlined the use of different antibiotics including linezolid [ 3 ], doxycycline [ 5 ], amoxicillin [ 9 ], ofloxacin [ 10 ], and daptomycin [ 11 ]. However, vancomycin remains a common initial option due to the gram-positive nature of the organism.…”

Bacteraemia Caused by Kytococcus schroeteri in a Pneumonia Patient

“…Though K. schroeteri is a part of the normal human skin flora, it causes systemic human infections associated with prosthetic devices and immunodeficiency. To date, K. schroeteri has been identified as a human pathogen in 17 cases; prosthetic valve endocarditis was the most common clinical presentation (n=8) [6][7][8][9][10][11][12][13], followed by pneumonia in immunocompromised patients (n=5) [14][15][16][17], ventriculoperitoneal shunt infection (n=2) [1,18], postoperative spondylodiscitis (n=1) [19], and implantrelated septic arthritis (n=1) [20]. K. schroeteri is a Gram-positive coccus; however, the isolate GNKS01 showed Gram-variable results in routine Gram staining.…”

Circulating microbial content in myeloid malignancy patients carries diagnostic and prognostic potential

“…In our setting, VI can therefore indicate the strength of association of a bacterial genus with each diagnosis. Among the genera with the highest VI (Figure 4b,c) are Dermabacter and Kytococcus, both of which are known as opportunistic pathogens frequently affecting immunocompromised individuals 34,35 . The species Kytococcus schroeteri in particular has been found in multiple patients with myeloid malignancies 36 .…”