Journal of clinical microbiology
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J. Clin. Microbiol. · Sep 2000
Diagnosis of amebic liver abscess and intestinal infection with the TechLab Entamoeba histolytica II antigen detection and antibody tests.
A noninvasive diagnostic test for amebic liver abscess is needed, because amebic and bacterial abscesses appear identical on ultrasound or computer tomography and because it is rarely possible to identify Entamoeba histolytica in stool specimens from patients with amebic liver abscess. Here we report a method of detection in serum of circulating E. histolytica Gal/GalNAc lectin to diagnose amebic liver abscess, which was used in patients from Dhaka, Bangladesh. The TechLab E. histolytica II test (which differentiates the true pathogen E. histolytica from Entamoeba dispar) detected Gal/GalNAc lectin in the sera of 22 of 23 (96%) amebic liver abscess patients tested prior to treatment with the antiamebic drug metronidazole and 0 of 70 (0%) controls. ⋯ PCR analysis of stool specimens was used to confirm that most antigen-positive but culture-negative specimens were true-positive: PCR identified parasite DNA in 27 of 34 (79%) of the antigen-positive, culture-negative stool specimens. Antigen detection was a more sensitive test for infection than antilectin antibodies, which were detected in only 76 of 98 (78%) amebic liver abscess patients and in 26 of 50 (52%) patients with intestinal infection. We conclude that the TechLab E. histolytica II kit is a sensitive means to diagnose hepatic and intestinal amebiasis prior to the institution of metronidazole treatment.
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J. Clin. Microbiol. · Jul 2000
Case ReportsRecurrent infections and chronic colonization by an Escherichia coli clone in the respiratory tract of a patient with severe cystic bronchiectasis.
A 39-year-old woman with cystic bronchiectasis had repeated pulmonary infections from 1996 to 1999, and 6 of a total of 28 isolates of Escherichia coli from sputum specimens were studied. Their identical antibiotype and randomly amplified polymorphic DNA patterns indicated a single clone of E. coli, which persistently colonized the respiratory tract, causing recurrent infections.
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J. Clin. Microbiol. · Jul 2000
Comparative StudyDiagnosis and clinical virology of Lassa fever as evaluated by enzyme-linked immunosorbent assay, indirect fluorescent-antibody test, and virus isolation.
The Lassa virus (an arenavirus) is found in West Africa, where it sometimes causes a severe hemorrhagic illness called Lassa fever. Laboratory diagnosis has traditionally been by the indirect fluorescent-antibody (IFA) test. However, enzyme-linked immunosorbent assays (ELISAs) for Lassa virus antigen and immunoglobulin M (IgM) and G (IgG) antibodies have been developed that are thought to be more sensitive and specific. ⋯ The presence of IFA during both acute and convalescent stages of infection, as well as significant interobserver variation in reading the slides, made interpretation difficult. However, the assay provided useful prognostic information, the presence of IFA early in the course of illness correlating with death. The high sensitivity and specificity, capability for early diagnosis, and prognostic value of the ELISAs make them the diagnostic tests of choice for the detection of Lassa fever.
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J. Clin. Microbiol. · May 2000
Evaluation of the LiPA MYCOBACTERIA assay for identification of mycobacterial species from BACTEC 12B bottles.
The LiPA MYCOBACTERIA (Innogenetics NV, Ghent, Belgium) assay was used to identify mycobacterial isolates using culture fluid from positive BACTEC 12B bottles. The LiPA method involves reverse hybridization of a biotinylated mycobacterial PCR fragment, a 16 to 23S rRNA spacer region, to oligonucleotide probes arranged in lines on a membrane strip, with detection via biotin-streptavidin coupling by a colorimetric system. This system identifies Mycobacterium species and differentiates M. tuberculosis complex, M. avium-M. intracellulare complex, and the following mycobacterial species: M. avium, M. intracellulare, M. kansasii, M. chelonae group, M. gordonae, M. xenopi, and M. scrofulaceum. ⋯ Seven additional mycobacterial species were LiPA positive for Mycobacterium spp. (six were M. fortuitum, and one was M. szulgai). The LiPA MYCOBACTERIA assay was easy to perform, and the interpretation of the positive bands was clear-cut. Following PCR amplification and gel electrophoresis, the LiPA assay was completed within 3 h.