[Accelerated determination of the Mycobacterium tuberculosis drug resistance with a semiliquid culture medium]. / Uskorennoe opredelenie lekarstvennoi ustoichivosti Mycobacterium tuberculosis s pomoshch'iu poluzhidkoi pitatel'noi sredy.

A medium was worked out whose consistence is close to liquid ones (the terminal concentration of agar-agar is 0.08%) and which enable a visual registration of growth of Mycobacterium tuberculosis (MBT) on days 3-4 after culture inoculation. The medium is based on the liquid synthetic medium of Soton, which is added 0.35% of nutrition agar and 10% (medium 1) or 25% (medium 2) of horse serum. The elaborated semi-liquid medium was used simultaneously with the standard method of absolute concentrations base on Levenstein-Jensen's medium to determine the drug resistance of 294 MBT clinical strains. The highest coincidence rate of results, in percent, was found for medium 2: for streptomycin--90.1%, for isoniazid--96.7%, and for rifampycin--96.3%, therefore, the mentioned medium can be referred to as an optimal one in a fast determination of the MBT resistance to three main anti-TB drugs. The deadline of registering the results for sensitive strains is 7 days, and for resistant strains it is 3-4 days, i.e. after the onset of primary growth signs.

[Sensitivity of Mycobacterium tuberculosis to levofloxacin]. / Issledovanie chuvstvitel'nosti mikobakterii tuberkuleza k levofloksatsinu.

Susceptibility of 92 strains of mycobacteria to levofloxacin (5, 10 and 50 mcg/mL) was investigated by indirect method of absolute concentrations on Levenstain-Jensen media. The investigation was performed on 85 strains of Mycobacterium tuberculosis isolated from 83 patients with different types of tuberculosis and also on drug-sensitive laboratory strains of M. tuberculosis H37Rv-M, H37Rv-GISK, Academia, M. bovis-bovinus 8, M. bovis BCG and on two strains of M. fortuitum with total resistance to antimycobacterial agents. 87.8 per cent of clinical isolates were multi-drug resistant. From one patient treated with ciprofloxacin two strains of M. tuberculosis were isolated--one resistant to 5 mcg/mL of levofloxacin and second strain-resistant to 10 mcg/mL of levofloxacin. All other clinical and laboratory strains of mycobacteria (97.8 per cent) were susceptible to all three concentrations of levofloxacin.