The Detection of Streptococcus pneumoniae in Peripheral Blood Smears from a Patient with Acute Promyelocytic Leukemia

A 31-year-old male patient presented with fever and gingival bleeding.Laboratory tests revealed a hemoglobin concentration of 105 g/L, a white blood cell count of 2.410 9 /L, and a platelet count of 1010 9 /L.The coagulation profile revealed a PT of 22.1s and an APTT of 43.9 s, with a fibrinogen level of 0.42 g/L, D-dimer of 15.3 g/mL, and FDPs of 56.9 g/mL, indicative of disseminated intravascular coagulation.The PML::RARA fusion gene was detected using peripheral blood samples.Abnormal promyelocytes (Figure 1 A) and a large number of bacteria, both within abnormal promyelocytes (Figure 1 B-C-D), were observed in the blood smear, and in the surrounding extracellular environment(Figure 1 D), accompanied by erythrocyte lysis.Subsequent bacterial identification confirmed the presence of Streptococcus pneumoniae bacteremia.Although the patient was treated with intravenous fluids, antibiotics, and blood products, he suffered a cardiac arrest and passed away four hours after his initial presentation.When bacteremia is suspected, a peripheral blood smear might be useful for rapid identification of microorganisms and take action while waiting for blood culture results.The presence of bacteria on a peripheral blood smear is a rare finding; however, when detected, it usually suggests massive bacteremia.Most cases follow a fulminant course of sepsis [1,2,3].Mortality typically occurs within hours or during the first 24 hours.