[Mycobacterial tests].
Tuberculosis is a bacterial disease caused by organisms of the M. tuberculosis complex, which is transmitted primarily by airborne droplet nuclei. Rapid and accurate detection of the bacilli is crucial for breaking the chain of transmission. Therefore, mycobacteriology laboratories have a major role to play in it. In this year, "the guideline for testing of M. tuberculosis, 2007" has been published. Here, it is emphasized that mycobacteriology laboratories must optimize their procedures for reporting results on the basis of current CDC recommendation: (i) reports of acid-fast examination of specimens within 24 hours of specimen collection, (ii) identification of M. tuberculosis within 21 days of specimen collection, and (iii) reports of drug susceptibility tests within 30 days of specimen collection. However, rapid mycobacteriology practices using liquid culture medium have many aerosol-generating handlings. Safety procedures, using a class II biological safety cabinet and so on, must be enforced for protecting laboratory personnel. As the improved technology available for use in mycobacteriology laboratories, such as nucleic acid amplification tests and others, are quite complicated, quality control is much more important than before. In this symposium, the 6 writers of "the guideline for testing of M. tuberculosis, 2007" have described the revised points of each chapters. We, as the chairpersons of this symposium, hope that this symposium would move a step forward toward rapid and accurate mycobacteriology practices in Japan. (1) Mycobacterial examinations and quality assurance: Satoshi Mitarai. It is well recognized that the mycobacterial examinations require careful quality assurances to perform highly reliable and safe laboratory examinations. As of 2003, a questionnaire survey was conducted to investigate the real state of laboratory examinations for mycobacterium. A total of 579 laboratories (291 of 390 hospitals and 288 of 397 private commercial laboratories) sent the replies, and the results were analysed from the points of quality assurance. Many laboratories adopted the sample concentration method and liquid culture methods. Meanwhile, the quality assurance activities for all examinations were not good enough to keep the quality and reliability. An effective quality assurance system should be necessary to maintain the good laboratory performances. (2) Revised "The guideline for testing of M.tuberculosis, 2007": Chiyoji Abe Rapid detection, species identification, and testing for drug resistance are necessary to control tuberculosis among patients and populations. Tuberculosis control officials and clinicians need access to prompt and reliable tuberculosis laboratory services. (3) The value of proper sputum collection instruction in detection of acid-fast bacillus: Takeshi HIGUCHI Modern techniques including molecular biology have been applied to routine laboratory works for rapid detection, identification, and drug susceptibility testing of mycobacteria. Even in using such techniques, however, poor quality specimens yield only poor results. To get a high quality specimen, particularly sputum samples, is very important. Therefore, laboratory technicians in our hospital have directly taught each patient how to expectorate good quality sputa since 2001. The teaching of patients has improved the rate of PI samples from 21.5% to 36.6% by Miller and Jones visual score of sputum. The teaching has also improved the rate of smear positive P1 samples from 11.4% to 28.8%. To teach patient how to get good sputa seems for useful for keeping the laboratory quality high. (4) The latest information for culture and the identification of acid-fast bacillus: Hajime Saitoh Culture methods are much more sensitive than smear ones to detect mycobacteria in the specimens. However, the duration of isolation by solid mediums is considerably long. Contemporary liquid culture methods allow for the rapid detection of M. tuberculosis complex, especially in smear positive samples. Therefore, in "the guideline for testing of M. tuberculosis, 2007", we recommend the routine use of liquid medium such as MGIT (Mycobacteria Growth Indicator Tube) or KRD in clinical laboratories. We also recommend the use of a simple immunochromatographic assay, Capilia TB, for rapid confirmation of the M. tuberculosis complex in liquid cultures. (5) The present condition of molecular detection and identification, and a future view: Mitsuaki NAGASAWA "The guideline for testing of M. tuberculosis, 2007" and the present condition of genetic screening, and a future view were described. It described about the kind of molecular detection and identification kit of Mycobacteria, results, an inspection request and extraction of a sample, preservation, and the measure against a biohazard. Moreover, it described also about quality assurance and the interpretation of a result. (6) Susceptibility testing of Mycobacterium tuberculosis: Toyoko OGURI Included below is a summary in susceptibility testing. The 9 methods that are used in the susceptibility test of Mycobacterium are in Table 1. The Committee for Mycobacterial Examination considered that a susceptibility test was attached great importance to rapidly reporting. (1) The target of organism for susceptibility test is Mycobacterium tuberculosis complex only. (2) The standard method is proportion methods using ogawa medium. (3) The inoculum suspension is recommended subculture growth in broth. (4) Rapid broth methods for susceptibility testing of M. tuberculosis are recommended susceptibility results for M. tuberculosis complex could be reported within 28 days of receipt of the specimen in the laboratory. (5) The detection of rpoB gene is added to the new method.
Takashima
Tetsuya
T
Osaka Prefectural Medical Center for Respiratory and Allergic Diseases, Kyoto University Hospital.
Higuchi
Takeshi
T
D001431:Bacteriological Techniques; D024881:Drug Resistance, Bacterial; D009161:Mycobacterium / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D013183:Sputum / Q000382:microbiology