CASE 1
A 3 years old boy with high risk acute lymphoblastic leukemia (ALL),
presented with 48 hours of fever without a source at emergency room.
Three weeks earlier, he experienced febrile neutropenia and grade III
mucositis (WHO scale) and persisted with profound neutropenia since
then. Six days before admission, he received third consolidation cycle
of chemotherapy. Laboratory tests revealed leucocytes count of 120
cells/μL (reference range, 5.5–14.5 × 103 cells/μL)
with an absolute neutrophil count of 20 cells/μL. Hemoglobin level was
7.2 g/dL (reference range, 10.2–12.7 g/dL) and platelet count was 8 x
103 cells/μL (reference range, 150 – 450 x
103 cells/μL ). C-reactive protein (CRP) level was
88.32 mg/L (reference range, <5 mg/L). He was admitted to
Pediatric Intensive Care Unit (PICU) and was commenced on vancomycin and
piperacillin/tazobactam after blood cultures were drawn. Peripheral
blood culture was positive at 14 hours. The quantitative central and
peripheral blood cultures were positive for 8 and 32 colony forming
units (CFU) respectively, each for Rothia mucilaginosa (Figure
1). Echocardiogram showed an image suggestive of vegetation in
the right atrium (11.6 mm x 15.6 mm) in relation to the central venous
catheter (CVC) tip in the interatrial septum (Figure 2). CVC was
removed. CVC tip and peripheral concomitant blood cultures were
negative. Susceptibility evaluation was performed in Mueller Hinton
Blood (MHB) Broth medium and epsilometry. Rothia mucilaginosa was
resistant to sulphamethoxazole/trimethoprim and susceptible to
penicillin, ceftriaxone, vancomycin (MIC ≤ 0.5), erythromycin and
clarithromycin. Piperacillin/tazobactam was replaced by ceftriaxone. On
third day of hospitalization he was transferred to the Oncology Unit. As
he persisted febrile until day eight of hospitalization a bone
scintigram, abdominal ultrasound and a cerebral magnetic resonance image
(MRI) were performed, all resulted normal. The patient completed 6 weeks
of intravenous vancomycin plus ceftriaxone with no evidence of
vegetation at 38 days of treatment.