Reassessment of the routine anaerobic culture and incubation time in the BacT/Alert FAN blood culture bottles.

A total of 9,130 blood cultures were collected from adult patients with suspected bloodstream infections. The recommended 20 mL sample of blood was divided equally between the aerobic and anaerobic FAN bottles and monitored in the BacT/Alert Microbial Detection System for a total of 5 days. There were 757 clinically significant positive culture pairs from 291 patients. Significant differences were found with greater recovery of Pseudomonas aeruginosa (p < 0.001), Acinetobacter spp. (p = 0.002), coagulase-negative staphylococci other than Staphylococcus epidermidis (p = 0.002), and Candida spp. (p < 0.001) from the aerobic bottle and greater recovery of anaerobic bacteria (p < 0.001) from the anaerobic bottle. Significantly more episodes of P. aeruginosa bacteremia (p < 0.003) and candidemia (p < 0.001) were detected by the aerobic FAN bottle and significantly more episodes of anaerobic bacteremia (p < 0.001) were detected by the anaerobic FAN bottle (Table 2). No other significant differences between systems in their detection of bacteremias were noted. Anaerobic bacteremias were encountered in diverse and often unpredictable clinical settings. All clinically significant episodes of bloodstream infection were detected within 4 days of incubation of their cultures. We conclude routine, rather than selective, use of the anaerobic FAN bottle in the blood culture set and a 4-day incubation of blood cultures in the BacT/Alert aerobic and anaerobic FAN bottles is an appropriate routine procedure.

Amplicor enterovirus polymerase chain reaction in patients with aseptic meningitis: a sensitive test limited by amplification inhibitors.

OBJECTIVE: To evaluate the sensitivity and specificity of reverse-transcription polymerase chain reaction (RT-PCR) and routine cell culture for the detection of enterovirus in cerebrospinal fluid. METHODS: Thirty-eight cerebrospinal fluid specimens were included. Cell culture was inoculated immediately and incubated for 14 days. An aliquot was kept frozen for Amplicor RT-PCR. Chart review was performed to determine the validity of the results. RESULTS: Nine of 38 specimens were positive for enterovirus by culture, and 14 were positive by RT-PCR. There were 7 discrepancies between the 2 methods. Six specimens were positive by RT-PCR and negative by the culture method. The 1 culture-positive but RT-PCR--negative specimen was determined to contain PCR inhibitors. All discrepant results were confirmed as true positives by chart review. Patients whose cerebrospinal fluid was negative by both methods had a final diagnosis other than enterovirus infection. CONCLUSION: Amplicor PCR is more sensitive than cell culture (93.3% vs. 60%) and is very specific. With the incorporation of appropriate controls for the detection of amplification inhibitors, RT-PCR could be a valuable tool in the diagnosis of enteroviral meningitis.

Reassessment of the incubation time in a controlled clinical comparison of the BacT/Alert aerobic FAN bottle and standard anaerobic bottle used aerobically for the detection of bloodstream infections.

This study assessed the minimum incubation time required to detect bloodstream infections during a controlled clinical comparison of the performance characteristics of the BacT/Alert aerobic FAN bottle and the standard anaerobic bottle used aerobically except on a selective basis. Blood was collected from adults with suspected bloodstream infections and inoculated into each bottle, which was monitored in the BacT/Alert Microbial Detection System. The anaerobic bottle was vented before incubation except when cultures were obtained from patients on the colorectal and gynecologic surgical and emergency services. Statistical analysis was limited to those culture sets in which each bottle was inoculated with > or = 8 mL of blood and bacterial growth was considered to be clinically significant. A total of 682 positive cultures from 243 patients satisfied the inclusion criteria. Significantly more isolates of Staphylococcus aureus (p < 0.001), S. epidermidis (p < 0.001), other coagulase-negative staphylococci (p < 0.001), Enterococcus spp. (p = 0.04), Escherichia coli (p = 0.03), all Enterobacteriaceae (p < 0.001), Pseudomonas aeruginosa (p = 0.001), and Candida spp. (p < 0.001) were detected by the aerobic FAN bottle. Significantly more septic episodes due to S. aureus, S. epidermidis, other coagulase-negative staphylococci, Enterobacteriaceae, P. aeruginosa, and Candida spp. were detected by the aerobic FAN bottle. Significantly more bacterial isolates were detected by the aerobic FAN whether or not antibiotics were being administered at the time of blood culture, whereas there were significantly fewer positive cultures in the vented standard anaerobic bottle when patients were receiving antimicrobial therapy than when they were not. All but 5% of positive cultures were detected within three days. Only six of the cultures requiring four or five days of incubation represented true misses, and only one of these six resulted in a change in therapy which, however, did not affect the patent's outcome.

Localized lichen sclerosus with nail loss.

A 52-year-old woman who developed a pale sclerotic second left toe with loss of the nail plate is described. Biopsy showed changes of lichen sclerosus. There were no other skin or genital lesions present.

Antimicrobial susceptibility testing of a clinical isolate of vancomycin-dependent enterococcus using D-alanine-D-alanine as a growth supplement.

Bacteremia due to a vancomycin-dependent enterococcus (VDE) occurred during long-term vancomycin therapy in a renal transplant recipient with underlying pancreatitis and a vancomycin-resistant enterococcal (VRE) wound infection and bacteremia. The VDE was isolated from blood during vancomycin therapy and grew only in the presence of vancomycin and D-alanine-D-alanine (DADA), a substance required for cell-wall synthesis. Colonies beyond the periphery of growth of the VDE around a vancomycin disk contained vancomycin-independent revertant mutants after 48 hours of incubation. Pulsed-field gel electrophoresis of the VDE, revertant mutant, the initial blood culture isolate of VRE, and an autopsy isolate showed that the four strains were identical. Antimicrobial susceptibility testing was performed using standard macrobroth and microbroth dilution methods. DADA was used as a growth supplement for macrobroth dilution susceptibility testing of the VDE isolate. Minimum inhibitory concentrations (MICs) were similar for the VRE isolate and the VDE revertant, which were both resistant to ampicillin, high-level gentamicin, ciprofloxacin, imipenem, vancomycin, and daptomycin, and were susceptible to fusidic acid, high-level streptomycin, rifampin, and a quinupristin-dalfopristin combination. The MICs of teicoplanin were 2 microg/mL or less and 16 microg/mL for the clinical VRE isolate and the VDE revertant, respectively. The autopsy isolate was resistant to all antimicrobials tested and showed a fourfold increase in MICs for quinupristin-dalfopristin compared with that of the original blood isolate. The VDE was susceptible to all drugs tested except vancomycin.

Measuring the topology of the universe.

Observations of microwave background fluctuations can yield information not only about the geometry of the universe but potentially about the topology of the universe. If the universe is negatively curved, then the characteristic scale for the topology of the universe is the curvature radius. Thus, if we are seeing the effects of the geometry of the universe, we can hope to soon see signatures of the topology of the universe. The cleanest signature of the topology of the universe is written on the microwave sky: There should be thousands of pairs of matched circles. These circles can be used to determine the precise topology and volume of the universe. Because we see hundreds of slices through the fundamental domain of the universe, we can use the microwave observations to reconstruct the initial conditions of the entire universe on the scale of a few megaparsecs.

Platelet adherence and phagocytosis. A method for the detection of platelet antibodies.

An assay was developed to identify platelet antibodies based on the adherence and phagocytosis of sensitized platelets by blood monocytes. Platelets obtained from normal HLA-typed donors were labeled with carboxyfluorescein diacetate (COFDA), fixed in paraformaldehyde, and sensitized with antibody. T cell-depleted mononuclear cells (MNCs) were mixed with antibody-sensitized platelets. Following an incubation phase, monocytes were isolated by adherence to glass tissue culture slides. Phagocytosis and adherence were evaluated by fluorescence microscopy. Thirteen of 18 donor-specific HLA antibodies and four of six sera from patients with chronic immune thrombocytopenic purpura enhanced platelet uptake. This assay was useful in detecting allo- and autoantibodies directed against platelets and may be valuable in investigating the pathophysiology of macrophage-mediated platelet destruction.