[Isolation and identification of non-tuberculosis mycobacteria].

Seeding of 117,579 samples of clinical materials at the Central Microbiological Laboratory, Moscow Research and Practical Centre of Tuberculosis, resulted in isolation of 15,786 (13,4%) mycobacterial cultures, with 15,333 (97.1%) ones being identified as M. tuberculosis complex and 490 (3.1%) as non-tuberculosis mycobacteria (NTM). Samples collected in the Moscow region were dominated by MAC, M. kansasii, M. xenopi, and M. fotuitum. Cultivation on solid and liquid media in an automated regime was shown to be optimal for isolation of NTM. Comparison of mycobacteria identification by microbiological methods and by high performance liquid chromatography revealed excellent agreement between the results (96.1%), with the latter technique taking less time to obtain them. Agreement between identification of acid-resistant mycobacterial cultures using the MAIS-dif test system and microbiological methods was estimated at 93.5%. IMS biochips may also be used to detect species composition of myobacteria because only one case of disagreement with the results of microbiological methods was documented in the study of 108 cultures by the two techniques.

[The detection rate of different species of non-tuberculous mycobacteria in Moscow].

The centralized microbiological laboratory of the Moscow Scientific-and-Practical Center for Tuberculosis Control (MSPCTC) conducted studies to isolate and identify mycobacterial cultures from clinical materials (sputum, bronchial and bronchoalveolar lavages) that had come from Moscow tuberculosis facilities in August 2005 to November 2008. The isolated mycobacterial cultures were identified by microbiological studies, high-performance liquid chromatography, and restriction fragment length polymorphism analysis of the hsp65 gene by means of the MAIS Dif test system developed at the MSPCTC. During the investigation, 117579 inoculations were made; 15786 (13.4%) of mycobacterial cultures were isolated, which included 15333 (97.1%) M. tuberculosis complex (MAC) cultures and 490 non-tuberculous mycobacteria (NTM) ones that amounted to 3.1% of the total number of the mycobacterial cultures isolated in this period. Two thirds of mycobacteria were referred to as slowly growing NTM (according to the Runyon classification; among them there were predominant MAC (32.40%), M. kansasii (14.7%), and M. xenopi (13.9%). Among the rapidly growing mycobacteria, M. fortuitum (21%) and M. chelonae/abscessus complex (6.5%) were isolated. MAC was frequently detected in all the examined administrative districts of the city However, among the slowly growing NTMs, M. kansasii was identified in the South and West districts even at a greater rate; M. xenopi ranked first in the West district. Among the rapidly growing NTM, M. fortuitum was most common in all districts. M. chelonae/abscessus complex was next in the East district (these NTMs were undetectable in other districts).

[Study of the sensitivity of non-tuberculous mycobacteria isolated on the solid and liquid media to antituberculous agents].

The centralized bacteriological laboratory of the Moscow Scientific-and-Practical Center for Tuberculosis Control Department of Public Health of the city of Moscow, examined the susceptibility of non-tuberculous mycobacteria (NTM) isolated and studied on the solid (Levenstein-Jensen) and liquid (Middlebrook 7H9 in the BACTEC-960 automatic system) media. A total of 159 cultures obtained from the solid medium and 132 from the liquid one were studied; of them there were 4 and 5 M. chelonae cultures, respectively, M. flavescense (n=6 and 4), M. fortuitum (n=34 and 28), MAC (n=52 and 44), M. xenopi (17 and 14), M. kansasii (n=41 and 35). Among the slowly-growing NTM, MAC was found to be resistant to streptomycin, isoniazid, rifampicin, and ethambutol in most cases. M. kansasii was sensitive to all basic antituberculous agents (ATAs) in most cases. M. xenopi was resistant to rifampicin in two thirds and to streptomycin, isoniazid, and ethambutol in a half of cases. Among the rapidly growing NTM, M. fortuitum was resistant to the study basic ATAs in most cases. No significant differences were found in the susceptibility/resistance of NTM to the basic ATAs depending on whether they had been isolated and their susceptibility evaluated on the solid and liquid media. Moreover, the duration of the entire study using the liquid medium was 2-3 times shorter.

[Study of the drug-sensitivity of nontuberculous mycobacteria].

The central bacteriological laboratory of the Moscow Research-and-Practical Center for Tuberculosis Control studied the sensitivity of nontuberculous mycobacteria (NTM) to a number of antituberculous drugs (streptomycin, isoniazid, rifampicin, ethambutol, kanamycin, ethionamide, cycloserine, ofloxacin) by the absolute concentration method (after isolating the cultures on both solid and liquid nutrient media). A total of 160 cultures, including M. chelonae (n = 4), M. flavescense (n = 6), M. fortuitum (n = 34), M. avium complex (MAC) (n = 52), M. xenopi (n = 18), M. kansasii (n = 41), M. marinum (n = 2), M. malmoense (n = 1), M. simiae (n = 1), and M. gastri (n = 1), were explored. MAC was found to be resistant to streptomycin, isoniazid, rifampicin, ethambutol, and ethionamide in most cases, to ofloxacin in a nearly half of cases, to canamycin and cycloserine in a third of cases. In most cases, M. kansasii was sensitive not only to first-, but also second-line chemical drugs. M. xenopi was resistant to rifampicin in two thirds of cases and to streptomycin, isoniazid, ethambutol, and ethionamide in a half of cases. This species of NTM was more sensitive to kanamycin, cycloserine, and oflaxacin. In the majority of cases, M. fortuitum was resistant to streptomycin, isoniazid, rifampicin, ethambutol, ethionamide, kanamycin, and cycloserine and sensitive to ofloxacin.

[Isolation of mycobacteria on different growth media and their identification].

AIM: To compare results of isolation of mycobacteria on different growth media. MATERIALS AND METHODS: From August 2005 to September 2008 Central Bacteriological Laboratory of MSPCTC performed 111,029 inoculations of clinical samples, isolated 14,513 (13.5%) cultures of mycobacteria, of which 14,095 (97.1%) belonged to M. tuberculosis complex and 418 (2.9%)--to non-tuberculous mycobacteria (NTM). RESULTS: Two thirds of isolated NTM belonged to slowly growing NTM (Ranyon classification), of which bacteria from M. avium complex as well as M. kansasii and M. xenopi predominated. M. fortuitum was the most frequently isolated between rapidly growing NTM. CONCLUSION: For isolation and identification of NTM the optimal was inoculation on at least 2 media: solid agar (Middlebrook 7H11) or egg medium and liquid medium (Middlebrook 7H9, in automated system BACTEC MGIT 960), each of which has its own advantages.

Dynamical surface affinity of diphasic liquids as a probe of wettability of multimodal porous media.

We introduce a method for estimating the wettability of rock/oil/brine systems using noninvasive in situ nuclear magnetic relaxation dispersion. This technique scans over a large range of applied magnetic fields and yields unique information about the extent to which a fluid is dynamically correlated with a solid rock surface. Unlike conventional transverse relaxation studies, this approach is a direct probe of the dynamical surface affinity of fluids. To quantify these features we introduce a microscopic dynamical surface affinity index which measures the dynamical correlation (i.e., the microscopic wettability) between the diffusive fluid and the fixed paramagnetic relaxation sources at the pore surfaces. We apply this method to carbonate reservoir rocks which are known to hold about two thirds of the world's oil reserves. Although this nondestructive method concerns here an application to rocks, it could be generalized as an in situ liquid/surface affinity indicator for any multimodal porous medium including porous biological media.

[The centralized mycobacteriological laboratory is a necessary component of a phthisiological service in large towns of Russia].

The paper presents the main points of the authors' own concept of the centralization of mycobacteriological service in large towns of the Russian Federation. The main points of step-by-step organizational and methodological measures required to solve this problem are described in detail. Consecutive measures to realize the proposed mycobacteriological service centralization model originated in January 2004 on a model of the Moscow Eastern Administrative District with 1380 thousand inhabitants are described.