Multicenter Evaluation of NeuMoDx Group B Streptococcus Assay on the NeuMoDx 288 Molecular System.

Group B Streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis in developed countries. Recommendations for antepartum GBS detection include enriched culture with several options for identifying GBS, some of which are time-consuming. To reduce the time for identification and determination of the maternal GBS colonization status, rapid nucleic acid amplification technologies have been developed and commercialized. For rapid detection of GBS, a three-site clinical study was conducted to evaluate the NeuMoDx GBS assay, a real-time PCR test performed for vaginal/rectal swab specimens in Lim broth enrichment culture on the NeuMoDx 288 molecular system (NeuMoDx system); these data were used to a support 510(k) submission. A total of 1,250 eligible remnant samples were prospectively enrolled and tested during the study. The results of the PCR assay were compared to the results of the Centers for Disease Control and Prevention (CDC)-recommended enriched-culture method, which served as the gold standard reference method for the study. The NeuMoDx GBS assay results yielded a sensitivity of 96.9% (95% confidence interval [CI] = 94.1 to 98.4), specificity of 96.0% (95% CI = 94.6 to 97.1), and a total agreement with the reference method of 96.2% (95% CI = 93.8 to 98.3). NeuMoDx GBS assay results were also compared to results obtained using the BD MAX GBS assay on the BD MAX system. The two systems demonstrated a total percent agreement of 98.0% (95% CI = 95.5 to 100.0). The performance of the NeuMoDx GBS assay implemented on the NeuMoDx system compared favorably to the CDC enriched-culture method and to the BD MAX GBS assay.

Detection and clinical significance of extended-spectrum beta-lactamases in a tertiary-care medical center.

The prevalence of extended-spectrum beta-lactamase (ESBL)-mediated resistance remains unknown for most hospitals, and national guidelines for testing and reporting ESBL-mediated resistance have not yet been developed. We undertook a study to determine the prevalence of ESBLs and the clinical need for testing in our tertiary-care medical center. Members of the family Enterobacteriaceae isolated over a 6-month period for which ceftazidime or ceftriaxone MICs were greater than 1 microg/ml were tested for production of ESBLs by the double-disk synergy method. Approximately 1.5% of isolates of the family Enterobacteriaceae (50 of 3,273), which were isolated from 1.2% of patients (23 of 1,844), were found to express ESBLs. ESBL-producing strains included eight different species and were isolated from patients located throughout the hospital, including outpatient clinics. By using the interpretive guidelines of the National Committee for Clinical Laboratory Standards, 26 to 39% of the isolates would have been reported to be susceptible to ceftazidime, depending upon the routine susceptibility method used. However, tests with cefpodoxime found all of the ESBL-producing strains to be resistant or intermediate. Nine patients infected with ESBL-producing isolates were treated with therapy which included an expanded-spectrum cephalosporin. Seven were cured. The deaths of the other two patients were not attributed to bacterial resistance missed by routine susceptibility testing. These observations suggest that in our tertiary-care medical center, it may not be clinically necessary or cost-effective at this time to institute additional testing on a routine basis to detect ESBL production in all clinical isolates of the family Enterobacteriaceae.

Feasibility study of magnetic resonance imaging-guided intranasal flexible microendoscopy.

Interventional magnetic resonance imaging (MRI) offers potential advantages over conventional interventional modalities such as X-ray fluoroscopy, ultrasonography, and computed tomography (CT). In particular, it does not use ionizing radiation, can provide high-quality images, and allows acquisition of oblique sections. We have carried out a feasibility study on the use of interventional MRI to track a flexible microendoscope in the paranasal sinuses. In this cadaver study, high-speed MRI was used to track a passive marker attached to the end of the endoscope. Automatic image registration algorithms were used to transfer the coordinates of the endoscope tip into the preoperative MRI and CT images, enabling us to display the position of the endoscope in reformatted orthogonal views or in a rendered view of the preoperative images. The endoscope video images were digitized and could be displayed alongside an approximately aligned, rendered preoperative image. Intraoperative display was provided in the scanner room by means of an liquid crystal display (LCD) projector. We estimate the accuracy of the endoscope tracking to be approximately 2 mm.

The Kleihauer-Betke test. Clinical utility, indication, and correlation in patients with placental abruption and cocaine use.

This study examines the indications for performing the Kleihauer-Betke (KB) test and makes recommendations for its use. Results of 523 KB tests performed during 1993 at our hospital (Cleveland, Ohio) are reviewed in conjunction with surgical pathology reports of placental findings, obstetric records, and toxicology results. We conclude that the KB test should be performed following a positive screening test on all Rh negative mothers of Rh positive infants. Additional indications include cases of maternal trauma, unexplained increased maternal alpha-fetoprotein levels, fetal distress with abnormal heart tracings, intrauterine fetal death, and cases of unexplained neonatal anemia. We note that the KB test should not be performed to detect suspected placental abruption.

B-cell prolymphocytic leukemia expressing discordant myeloid-associated antigens in simultaneous specimens from bone marrow and peripheral blood.

The case of a 73-year-old man with B-cell prolymphocytic leukemia (PLL) and rapid clinical demise is reported. Flow cytometric immunophenotyping results of specimens obtained from the patient demonstrated a monoclonal CD5 positive B-cell population with myeloid-associated marker expression, which was discordant: CD15 and CD11b were expressed in bone marrow leukemic cells, whereas peripheral blood leukemic cells showed virtually no expression of these markers. Discordant immunophenotyping results between bone marrow and peripheral blood cells have been reported recently. Additionally, investigators have associated expression of CD13 and CD11b by chronic B-cell lymphoid leukemias with a more aggressive clinical course and shorter survival. Expression of these myeloid-associated antigens by B-cell prolymphocytes in PLL has not been widely reported. Cytogenetic analysis revealed a karyotype of 46,XY/?44,XYdel(1q),del (3p), whereas molecular genetic studies demonstrated immunoglobulin gene rearrangements in both heavy and light chain regions. Cytochemical staining for PAS (periodic acid-Schiff), nonspecific esterase and methyl-green-pyronin was positive in leukemic cells.

Variables related to body-weight status of mentally retarded adults.

Mentally retarded male and female adult subjects displayed mean body weights in excess of their ideal weights; excessive body weight of females was also apparent in comparison to normative data for the United States. Maintenance of appropriate weight appeared to be more likely in a controlled residential setting than in the natural home environment. These sex and environmental relationships could not be explained by medication and dietary programming differences, and age, race, and level of retardation were unrelated to body weight.