Saceanu C A, Pfeiffer N C, McLean T
Clinical Microbiology Laboratory at Lincoln Medical and Mental Health Center, Bronx, New York 10451.
J Clin Microbiol. 1993 Sep;31(9):2371-4. doi: 10.1128/jcm.31.9.2371-2374.1993.
Early identification and isolation of tuberculosis patients is of utmost importance to minimize the risk of further epidemic spread of the disease. The traditional concentrated acid-fast smears are not very reliable tools for the presumptive diagnosis of tuberculosis. Acid-fast bacillus (AFB) smears from 120 patients specimens and 80 simulated AFB samples were processed according to standard laboratory procedures and by cytocentrifugation (Cyto-Tek, Ames Division, Miles Laboratories, Inc., Elkhart, Ind.). Prior to dispensing of samples into the Cyto-Tek chambers, specimens were liquefied and decontaminated by mixture with an equal volume of 5% sodium hypochlorite (household bleach). Culture and smear results were correlated. Of 120 patient specimens, 43 were culture and smear negative by both methods. Ten specimens were overgrown with mold and bacteria, but 2 of them had positive AFB smears by cytocentrifugation only. There were 67 positive AFB cultures, with 67 positive cytocentrifuge smears and 34 positive smears by the conventional technique. Of the 80 simulated positive AFB samples, all grew mycobacteria on culture. Smears from the 10(5)- to 10(3)-CFU/ml specimens were positive by both methods. The simulated samples with 10(2) CFU/ml yielded smears positive only by cytocentrifugation. The Cyto-Tek AFB smears had a greater correlation with positive culture than did the smears from concentrated specimens. The sensitivity, efficiency, and rapidly of the Cyto-Tek AFB smear technique resulted in increased detection of mycobacteria in clinical specimens. The simplicity and safety of this method will enable qualified mycobacteriology technologists to rapidly and accurately perform sputum smears for AFB at clinics, emergency rooms, and field sites, as well as in the traditional laboratory setting.
早期识别和隔离结核病患者对于将疾病进一步流行传播的风险降至最低至关重要。传统的浓缩抗酸涂片对于结核病的初步诊断并非非常可靠的工具。按照标准实验室程序并通过细胞离心法（Cyto-Tek，迈尔斯实验室公司艾姆斯分部，印第安纳州埃尔克哈特）对120份患者标本和80份模拟抗酸杆菌样本的抗酸杆菌涂片进行处理。在将样本分配到Cyto-Tek腔室之前，通过与等体积的5%次氯酸钠（家用漂白剂）混合使标本液化并去污。将培养结果和涂片结果进行关联。在120份患者标本中，43份通过两种方法培养和涂片均为阴性。10份标本被霉菌和细菌过度生长，但其中2份仅通过细胞离心法抗酸杆菌涂片呈阳性。有67份抗酸杆菌培养阳性，其中67份细胞离心涂片阳性，34份通过传统技术涂片阳性。在80份模拟抗酸杆菌阳性样本中，所有样本在培养时均生长出分枝杆菌。来自10(5)至10(3)CFU/ml标本的涂片通过两种方法均为阳性。含10(2)CFU/ml的模拟样本仅通过细胞离心法涂片呈阳性。与浓缩标本涂片相比，Cyto-Tek抗酸杆菌涂片与培养阳性的相关性更高。Cyto-Tek抗酸杆菌涂片技术的敏感性、效率和快速性导致临床标本中分枝杆菌的检测增加。该方法的简单性和安全性将使合格的分枝杆菌学技术人员能够在诊所、急诊室、现场以及传统实验室环境中快速准确地进行抗酸杆菌痰涂片检查。
