Clostridium haemolyticum Infection: A Cause of Hemolytic Anemia in a Patient with Bone Marrow Necrosis

Clostridium haemolyticum is a sporulating Gram-positive anaerobic rod that is considered to be one of the most fastidious and oxygen-sensitive anaerobes. It is a well-known animal pathogen and the cause of bacillary hemoglobinuria primarily in cattle. To date, human infections caused by C. haemolyticum have been reported in three patients with malignant underlying diseases. We present herein the case of a 30-year-old obese woman with no significant past medical history who developed bacteremia caused by C. haemolyticum with massive intravascular hemolysis associated with bone marrow necrosis and acute renal failure. Because of subculture failure, the diagnosis was made on the basis of 16S rDNA sequencing and next-generation sequencing. The patient, who had been afebrile for 20 days after a 17-day-course of antibiotics, experienced a second bacteremic episode caused by C. haemolyticum. After having been successfully treated for 42 days with clindamycin and amoxicillin-clavulanic acid, the patient developed acute myeloid leukemia as a result of bone marrow regeneration. Although uncommon in humans, infections caused by C. haemolyticum are severe and should be considered in a febrile patient who has severe hemolytic anemia. This case also highlights the importance of using molecular techniques for the identification of this fastidious anaerobic organism.

E Test versus Agar Dilution for Antimicrobial Susceptibility Testing of Viridans Group Streptococci

Viridans group streptococci (VGS) are commonly isolated from the blood of hospitalized patients. The E test represents a convenient method for determining the MICs for VGS, but for this purpose it has not been well validated against reference methods. In this study, 180 unselected VGS isolates were identified to a species level, and the MICs of penicillin, cefuroxime, cefotaxime, and vancomycin were determined by both agar dilution and the E test. Available data regarding demographic and laboratory variables for each VGS bacteremic episode were collected, the significance of each VGS isolate was assessed, and the associations between and among laboratory and clinical variables were investigated. Among all VGS isolates, 68.3% (median of three runs) were found to be fully susceptible to penicillin by agar dilution. The E test and agar dilution showed average agreements (within ±1 dilution) of 92.2% for penicillin, 95.7% for cefuroxime 91.3% for cefotaxime, and 86.7% for vancomycin. Agreements over serial E tests and serial agar dilutions were excellent for β-lactam agents (intraclass correlation coefficients, >0.9) but less impressive for vancomycin. Very major error rates for the E test were ≤0.7%, and combined major and minor error rates were within acceptable limits for all antimicrobial agents tested. Lysis-centrifugation culture methods were more often associated with clinically insignificant VGS isolates; otherwise, no associations between clinical and laboratory variables were noted.

Patterns of Illness in the Highly Febrile Young Child: Epidemiologic, Clinical, and Laboratory Correlates

Three hundred one episodes of fever ≥103 F were documented in 375 infants and young children observed in a comprehensive care clinic during the period October 1974 to October 1978. Of such highly febrile illnesses 79% were accompanied by respiratory tract signs or symptoms, 7% by disease at a site other than the respiratory tract, and 22% of illnesses had no localizing signs or symptoms. Viral cultures were obtained from the respiratory tract in 178 cases and were positive in 68:57/ 134 from respiratory illness; 2/4 from illness at sites other than the respiratory tract; and 9/40 in children without localizing disease. Bacterial cultures of the upper respiratory tract were obtained in 191 illnesses, but the overall rate of isolation of Haemophilus influenzae, Streptococcus pneumoniae and group A streptococci (46%) did not differ from that in a group of well children (39%). Bacterial cultures of the blood were obtained in 89 patients with fever ≥103 F and in an additional 41 children with lower temperatures. Nine children had documented systemic bacterial disease (eight positive blood cultures and one positive CSF). The rate of clinically apparent systemic bacterial disease in these otherwise normal infants was one bacteremic episode per 94 years of child care.