The Brief Case: Recurrent Chromobacterium violaceum Bloodstream Infection in a Glucose-6-Phosphate Dehydrogenase (G6PD)-Deficient Patient with a Severe Neutrophil Defect

Abstract

A 37-year-old male with a medical history of glucose-6-phosphate dehydrogenase (G6PD) deficiency (Beaumont variant) presented at the emergency department (ED) with fatigue, malaise, generalized joint pains, and chills.On exam, he was febrile (40.2°C) and tachycardic (143 beats/min) while normotensive (124/75 mm Hg) and oxygenating well on ambient air (99% SpO 2 ).His blood chemistries were remarkable, with elevated lactic acid at 3.27 mmol/liter (range, 0.5 to 2.20 mmol/liter) and procalcitonin at 0.35 ng/ml (range, Ͻ0.05 ng/ml).Additional lab findings showed a normal white blood cell (WBC) count (7,192 cells/l; range, 4,000 to 11,000/l), with 80% neutrophils, and signs of acute hemolytic anemia, with high reticulocytes at Ͼ17.97% (range, 0.59 to 2.24%), low hemoglobin (Hgb; 9.9 mg/dl; range, 12.2 to 16.4 mg/dl), hyperbilirubinemia (unconjugated bilirubin, 3 mg/dl; range, 0.1 to 1.1 mg/dl), and high ferritin level (3,240 ng/ml; range, 18 to 464 ng/ml).He was given a dose of 1 g meropenem intravenously (i.v.) and admitted for further management of suspected septicemia.The urine and sputum cultures collected at the ED were negative, but aerobic blood cultures became positive after 18 h of incubation.The initial Gram stain showed Gram-negative rods (Fig. 1A); however, the Verigene Gram-negative blood culture nucleic acid test (BC-GN; Luminex Co., Austin, TX) did not identify any organisms.Blood bottle subcultures grew purple colonies of Gram-negative rods on both 5% sheep blood (SBA) and MacConkey (MAC) agars (Fig. 1B andC).Identification by matrixassisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (Vitek MS; bioMérieux, Inc., Hazelwood, MO) revealed Chromobacterium violaceum, which was confirmed by 16S rRNA sequencing (GenBank accession number MH790126) with 99.93% (1,470/1,471 nucleotides) identity to C. violaceum ATCC 12472 T .Antimicrobial susceptibility testing was performed using a Sensititre Gram-negative nonfermenters MIC plate (Thermo Fisher Scientific, Waltham, MA) and an Etest (bioMérieux Inc., Hazelwood, MO) for meropenem.The MIC values were reported with no interpretation (Table 1).He was given 14 days of high dose meropenem (2 g every 8 h [q8h] i.v.) and doxycycline (100 mg twice a day oral [BID]).Due to a continuous decline in his Hgb and platelets, he was given 1 unit of packed red blood cells and platelet transfusion on hospital day (HD) 2. Subsequent blood cultures drawn 48 and 96 h postbacteremia were negative.On HD 12, he was discharged with doxycycline maintenance therapy.