Screening and Identification of Unexpected Red Cell Antibodies by Simultaneous LISS/Coombs and NaCl/Enzyme Gel Methods

We evaluated the clinical usefulness of simultaneous LISS/Coombs and NaCl/Enzyme testing using the gel method for screening and identification of unexpected antibodies in 15,014 samples. When unexpected antibodies were detected by either screening test, those antibodies were identified using both the LISS/Coombs and the NaCl/Enzyme gel test. The positive screening rates of the LISS/Coombs, NaCl/Enzyme, and combined tests (excluding 25 autoantibody cases) were 0.48%, 1.29%, and 1.39%, respectively. Among the 57 samples positive by both screening methods, the antibodies in 19.3% could be identified only by the NaCl/Enzyme method. Among the 137 samples positive only by NaCl/Enzyme screening, 74.5% showed positive results in antibody identification only by the NaCl/Enzyme test, although 7.3% were also positive in the LISS/Coombs test. The NaCl/Enzyme method thus showed about threefold higher detection rates than the LISS/Coombs method, especially in screening for Rh antibodies, and higher exact identification rates and discriminatory power for identifying mixed antibodies. Addition of the NaCl/Enzyme method to routine laboratory procedures may detect and identify considerable numbers of significant antibodies that might be missed if only the LISS/Coombs method is used.

Acute Lymphadenitis with Cellulitis Caused by Staphylococcus lugdunensis / 대한진단검사의학회지

Although coagulase-negative staphylococci (CNS) have been considered part of the resident flora on the human skin, Staphylococcus lugdunensis is an unusually virulent CNS and can cause many types of infection. We report a rare case of acute lymphadenitis with cellulitis in the right infraauricular region caused by S. lugdunensis. A 62-yr-old woman visited the Department of Otolaryngology of Busan Paik university hospital. She had a palpable mass and swelling in the right infraauricular region and complained of aggressive pain and a febrile sensation in the region for 5 days. On the suspicion of abscess with infection, percutaneous aspiration was performed and smooth, flat, white, opaque colonies grew on a blood agar plate as a pure culture. The biochemical test results showed the organism to be catalase positive, tube coagulase negative, ornithine decarboxylase positive, slide coagulase positive, and latex agglutination tests for coagulase positive. The API Staph Kit was used to identify the isolate to the species level as S. lugdunensis with a 64.6% probability (profile 6716152). We confirmed the species identification of this strain by 16S rDNA sequence analysis. The patient's clinical condition improved with appropriate antimicrobial therapy and pus drainage.

Pseudo-outbreak of Klebsiella oxytoca fromBronchial Washing Specimens / 대한임상미생물학회지

BACKGROUND: We noticed a sudden increase in the isolation of Klebsiella oxytoca from bronchial washing specimens during May to June 2006. An epidemiological investigation was conducted to identify the cause of the outbreak and to implement appropriate infection control measures. METHODS: A total of 18 isolates of K. oxytoca were found. The 14 bronchial washing specimens that yielded K. oxytoca were taken in the outpatient bronchoscopy suite, and the other 4 specimens were obtained by a portable bronchoscopy. The medical records and microbiologic findings of these patients were reviewed. Environmental samples from two bronchoscopes and the bronchoscopy suite were cultured. The relations between the available 10 isolates from bronchial washing fluid were investigated by pulsed-field gel electrophoresis (PFGE). RESULTS: No patients were judged to have had true infections attributable to K. oxytoca either before or after bronchoscopy. Cultures of samples from two bronchoscopes and related environment did not grow K. oxytoca. The PFGE analysis showed that 8 of 10 isolates had a similar pattern of DNA fragments. An infection control strategy was implemented, including adequately cleaning and disinfecting the bronchoscopes, and a sharp reduction in the incidence of K. oxytoca from bronchial washing samples followed. CONCLUSION: The sudden increase of K. oxytoca from bronchial washing specimens was a pseudo-outbreak. We presumed that the bronchoscopes became contaminated during a procedure in a patient colonized with K. oxytoca in the upper-respiratory tract.

Evaluation of a Colorimetric Antifungal Susceptibility Test by 2,3-Diphenyl-5-Thienyl-(2)-Tetrazolium Chloride for Fluconazole in Candida Species Isolated from Clinical Specimens / 대한임상미생물학회지

BACKGROUND: The aims of this study were to evaluate the colorimetric antifungal susceptibility test to fluconazole using 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC) for various Candida species isolated from clinical specimens and to compare the results with those of the CLSI M27-A2 standard method. METHODS: The fluconazole MICs for 204 clinical Candida isolates consisting of 100 C. albicans, 45 C. glabrata, 28 C. tropicalis, 22 C. parapsilosis, and 9 other Candida species were determined by the CLSI and STC colorimetric methods. RESULTS: All 204 Candida strains were grown on the growth control wells of CLSI standard plates, but 26 Candida strains (6 C. albicans and 20 C. tropicalis) were not grown on those containing STC. Therefore, those 26 Candida strains were excluded from the comparison of MICs in this report. Overall, the STC visual and spectrophotometric readings of fluconazole MICs showed 96.1% (N=171) and 89.9% (N=160) accordance with those obtained by the CLSI standard method within 2 dilutions, respectively. The STC visual reading of C. albicans showed 76.6, 92.6, and 95.8% accordance with the CLSI standard method within 1, 2, and 3 dilutions, respectively. The agreement between the two endpoint determinations of the STC colorimetric method (visual and spectrophotometric readings) was excellent, with 170 of the 178 MICs within 2 dilutions. CONCLUSION: The STC colorimetric method to determine the MIC for Candida species except C. tropicalis showed high levels of agreement with CLSI method. And also, it is useful with objective and easy interpretation.