Bhat Sevitha, Radhakrishna M, Kotian Mohan, Rao Sunil
Department of Microbiology, Kasturba Medical College, Mangalore, Karnataka, India.
Indian J Med Sci. 2010 Mar;64(3):99-103.
Tuberculosis (TB) remains one of the major causes of death from a single infectious agent worldwide. Its resurgence in 1990s is primarily due to co-infection with HIV and the emergence of multi-drug-resistant (MDR) strains. Our objectives in this study were demonstration and grading of acid-fast bacilli in smears from sputum specimens of clinically newly diagnosed pulmonary TB patients, isolation of the organism, speciation and drug susceptibility testing of Mycobacterium tuberculosis isolates to isoniazid (H), rifampicin (R), streptomycin (S), and ethambutol (E).
Sputum specimens were collected from 150 patients. Smear examination was done after Ziehl-Neelsen staining. The specimens were cultured onto Lowenstein Jensen media after Petroff's method of concentration. The growth was identified as M. tuberculosis with standard tests. Sensitivity of 50 isolates of tubercle bacilli to anti-TB drugs H, R, S, E were determined by Resistance-Ratio method.
Out of 150 sputum specimens examined, 62(41.3%) were smear positive. Out of these 62,56 grew on culture. 50 isolates of M. tuberculosis were picked up for drug susceptibility testing. Total of 31 (62%) were resistant to S, 14(28%) to H, 9(18%) to R, 6(12%) were resistant to E and 2 strains (4%) were resistant to H and R.
From the small cohort, incidence of primary MDR-TB was found to be 4% in this region, which is within the expected range.
结核病仍是全球单一传染源导致死亡的主要原因之一。其在20世纪90年代的再度流行主要归因于与艾滋病毒的合并感染以及多重耐药（MDR）菌株的出现。本研究的目的是对临床新诊断的肺结核患者痰标本涂片进行抗酸杆菌的显示和分级，分离该病原体，对结核分枝杆菌分离株进行菌种鉴定及对异烟肼（H）、利福平（R）、链霉素（S）和乙胺丁醇（E）进行药敏试验。
收集150例患者的痰标本。经萋-尼染色后进行涂片检查。采用彼得罗夫浓缩法后，将标本接种于罗-琴培养基上。通过标准试验将生长物鉴定为结核分枝杆菌。采用耐药比法测定50株结核杆菌对抗结核药物H、R、S、E的敏感性。
在检查的150份痰标本中，62份（41.3%）涂片阳性。在这62份涂阳标本中，56份培养生长。选取50株结核分枝杆菌分离株进行药敏试验。总共有31株（62%）对S耐药，14株（28%）对H耐药，9株（18%）对R耐药，6株（12%）对E耐药，2株（4%）对H和R耐药。
在这个小队列中，该地区原发性耐多药结核病的发生率为4%，在预期范围内。
