Analytical evaluation of the cobas® 6800 system for the detection and quantification of BK Virus (BKV) and Epstein Barr Virus (EBV) at a US solid organ and hematopoietic stem cell transplant center.

The cobas® EBV and BKV assays are the first FDA-approved, quantitative assays for monitoring posttransplant reactivation of these viruses. In this study, we assessed performance of the fully-automated cobas® assays, compared with Diasorin Molecular ASR, our laboratory developed test, and demonstrated a strong interassay correlation for BK and EBV monitoring.

A case report of Nocardia spp. infective endocarditis in an injection drug user.

BACKGROUND: Nocardia-related endocarditis is rare. Intravenous drug use with nonsterile injection practices is a potential risk factor for nocardia infection. Disseminated nocardiosis with endovascular involvement is rarely reported in immunocompetent individuals. CASE PRESENTATION: A 54-year-old male was diagnosed with infective endocarditis due to Nocardia asteroides with septic emboli in the brain and spleen. The use of a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) rapid diagnostic system was beneficial in identifying the causative organism. He was empirically treated with combination therapy consisting of three antibiotics. Antimicrobial susceptibility testing indicated that all three antibiotics had favorable minimum inhibitory concentrations (MICs). Due to his clinical status, he was not a surgical candidate. Patient passed away after discharge to hospice. CONCLUSIONS: This case demonstrates unique challenges in the identification, diagnosis, and management of Nocardia-related infective endocarditis. A detailed history of injection practices should guide clinicians in assessing the risk for environmental pathogens. Valvular surgery and combination antibiotic therapy should be recommended for all eligible patients to improve the chances of survival.

Screening for Bacteremia in Trauma Patients: Traditional Markers Fall Short.

BACKGROUND: Deranged physiology in trauma complicates the clinical identification of sepsis, resulting in overscreening for bacteremia. No clinical signs or biomarkers accurately diagnose sepsis in this population. Our objective was to evaluate the accuracy of the current criteria used to prompt screening for bacteremia in trauma patients and determine independent predictors of bacteremia. MATERIALS AND METHODS: Adult trauma patients admitted to our level I academic trauma center who had blood cultures (BCs) drawn were identified. Those with positive BCs were compared to those with negative or false positive BCs. False positive was defined as a BC deemed contaminated and not treated at the discretion of the attending physician. RESULTS: Over a 2-year period, 366 trauma patients had BCs drawn. After excluding surveillance cultures (those drawn to demonstrate bacteremia clearance), 492 unique BC sets were evaluated; 104 (21.1%) BC sets were positive; 30 (28.8%) of these were falsely positive, resulting in a true-positive rate of 15% in the screened population. Univariate analysis suggested temperature and heart rate were associated with positive BC, while multivariable analysis found only the presence of a central line and lactic acid to be predictive. Procalcitonin (PCT) was poorly predictive, with a positive predictive value of 18% and a negative predictive value of 91%. CONCLUSION: Current tools for identifying bacteremia in trauma patients result in overscreening. PCT may have a limited role as a negative predictor for bacteremia. Given that false-positive BCs have negative patient and economic consequences, future study should focus on development of alternative screening modalities.

Fatal autoimmune hemolytic anemia due to immunoglobulin g autoantibody exacerbated by epstein-barr virus.

Most cases of autoimmune hemolytic anemia (AIHA) are caused by the production of an autoantibody that targets determinants on red blood cells (RBCs). This autoantibody can be immunoglobulin (Ig) G, IgM, or IgA. Some autoantibodies react optimally at 0° to 4°C (ie, cold agglutinin) and usually are clinically insignificant. High-titer cold agglutinins are associated with IgM autoantibody and complement fixation induced by infectious agents, including the Epstein-Barr virus (EBV). This case report describes a 31-year-old man who had jaundice, a hemoglobin of 6.0 gdL, and was diagnosed with a hemolytic crisis of AIHA. He received a total of 11 RBC transfusions during a 15-hour period without sustained response and later died. The direct antiglobulin test results for this patient were positive, whereas the cold-agglutinin-testing results were negative. We detected EBV DNA in blood via polymerase chain reaction (PCR). We report a rare case of AIHA associated with an IgG autoantibody and exacerbated by EBV infection, causing a fatal hemolytic anemia.

Four-year experience with simultaneous culture and Shiga toxin testing for detection of Shiga toxin-producing Escherichia coli in stool samples.

We report our experience with universal Shiga toxin-producing Escherichia coli (STEC) screening using culture and Shiga toxin antigen testing over 4 years. Twelve cases were detected-8 detected by both culture and Shiga toxin immunochromatographic assay (IA), 3 by culture, and 1 by IA only. The addition of Shiga toxin testing is of questionable benefit over culture alone for detection of STEC in areas of low prevalence.

Filamentous bacteria masquerading as fungi: a diagnostic pitfall in direct smear interpretation with report of two cases.

Bacteria, particularly Gram-negative bacilli, can develop abnormal morphology after the administration of subinhibitory concentrations of antibacterial agents. Filamentation is a common response in which bacteria replicate but incompletely divide, leading to long slender chains that resemble fungal hyphae. Pathologists are frequently consulted to examine direct smears of body fluids, which often contain microorganisms. Antibiotic-related filamentous morphology may resemble fungal hyphae and this potential misinterpretation can lead to inappropriate treatment for presumed fungal infections. Two cases are described in which direct smears of body fluids were examined by on-call pathology residents who misinterpreted filamentous bacteria as fungal organisms, with one case leading to the initiation of antifungal medication. Although well-established within the field of microbiology, many residents and practising pathologists are less familiar with antibiotic-related bacterial morphology, as it may not be routinely encountered. It is important for pathologists to be aware of this phenomenon in order to avoid misinterpretation.

Cushing's syndrome and nocardiosis associated with a pulmonary carcinoid tumor: report of a case and review of the literature.

Ectopic hormone production is an uncommon complication of neoplastic lung disease. Rarely, patients may present with signs and symptoms of systemic endocrine dysfunction related to a hormone-secreting tumor. Bronchopulmonary carcinoids are the most common neoplasm implicated in ectopic ACTH-dependent Cushing's syndrome. Persistent hypercortisolism, such as that which occurs in Cushing's syndrome, causes immunosuppression and makes patients vulnerable to opportunistic infections. We present a case of a 42-year-old woman diagnosed with ACTH-dependent Cushing's syndrome which was originally thought to stem from a pituitary lesion as interpreted on magnetic resonance imaging. Her symptoms persisted after undergoing hypophysectomy, and further work-up involving a fine needle aspiration of the left lung revealed an ACTH-producing carcinoid tumor. Before treatment could be administered, the patient developed several new suspicious nodules in the left lung that were shown by fine needle aspiration to be infectious in nature. A Gram stain revealed numerous Gram positive branching organisms, and culture of the specimen grew Nocardia asteroides. Her pulmonary infection was treated with antibiotics and she underwent successful ablation of the carcinoid tumor.

Macrolide resistance phenotypes in Streptococcus pneumoniae in Santiago, Chile.

The mechanism of resistance was investigated in 39 macrolide-resistant clinical isolates of Streptococcus pneumoniae isolated from January 1997 to July 1999 in Santiago, Chile. Our results showed that 22 (56.5%) were macrolide-resistant, clindamycin-susceptible isolates (M phenotype) and 17 (43.5%) were macrolide and clindamycin resistant (MLS(B) phenotype). mefE gene was detected in all M phenotype, while ermB gene was detected in all MLS(B)-phenotype strains. Serotype 14 was the most frequent serotype among M-phenotype strains, and serotypes 19 and 23F were the most frequent serotypes in MLS(B) strains. These results demonstrate that both phenotypes of macrolide-resistant S. pneumoniae are found in Santiago, Chile, with the M phenotype predominating.