Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_2894_Библиотеки_им_академика_М_И_Перельмана

In order to prevent contamination, it uses liquid media like Middlebrook 7H9 sup­plemented with enrichment such as Oleic acid, Albumin, Dextrose and Catalase (OADC) enrichment, which is a mixture of bovine albumin, dextrose, oleic acid, and catalase, and PANTA antibiotic (polymixin B, amhotericin B, nalidixic Acid, trimethoprim, and azlocillin), which prevents the growth of contaminants.

It notices a change in medium pressure brought on by bacteria’s generation of car­bon dioxide. Before usage, 1mL of each antibiotic dilution and 1mL of growth supplement are added to ESP myco bottles. In place of the antibiotic solution in the control bottle, 1cc of sterile distilled water was introduced. Each drug-containing bottle and control bottle received 0.5mL of a 1:10 diluted 1McFarland solution as an inoculation. The ESP device is then lled with bottles. If an organism produces a signal from the drug-containing bottle within 3days after the control, it is deemed resistant; if it does not produce a signal within 3days, it is deemed susceptible [17].

The manner of treatment regimens utilized for non-tubercular mycobacterial infec­tions is guided by DST.The test culture is added to two tubes of Middlebrook 7H9 liquid medium for inoculation. One of the MGIT tubes is supplemented with a known concentration of a test substance, and the growth is compared to the un­inoculated one. If the test medicine is effective against the isolated NTM, it will suppress uorescence and impede growth, whereas the growth control will grow unhindered and exhibit increased uorescence. The BACTEC 960 equipment mea­sures growth and instantly determines whether the results are resistant or sensitive.

Treatment for M. kansasii typically involves the use of clinically effective medica­tions, such as isoniazid, rifampicin, and ethambutol. A different medicine combina­tion, rifampicin, ethambutol, and clarithromycin, has been proven to be efcient. For testing with primary treatment medications, broth micro-dilution, and agar pro­portion have been used. It is advised to use CAMHB supplemented with 5% OADC while micro-dilution broth. The growth of micro-dilution trays is observed after 7–14days of incubation at 37°C and 5–10% CO2. CO2 must be avoided when test­ing macrolides. Untreated strains’ MICs for these medications will fall within a specic range, so routine testing is typically unnecessary. Treatment failure happens

Variability in susceptibility to therapeutically effective antimicrobial drugs or a siz­able risk of developing acquired mutational resistance to one or more of these agents serves as the primary justications for susceptibility testing of NTM. M. marinum infections have been successfully treated with rifampicin, doxycycline, minocy­cline, trimethoprim-sulfamethoxazole, and clarithromycin as single agents. For individuals whose treatment has failed after several months and whose cultures are still positive, testing for M. marinum may be an option. It has been recommended to test for M. marinum using a 5% OADC supplemented with CAMHB in a broth micro-dilution. For 7days, incubation should take place between 28 and 30°C.A macrolide should not be tested with CO2 and should be incubated at 5 to 10% CO2.

For the purpose of assessing the susceptibility of rapidly proliferating mycobacte­ria, the Clinical and Laboratory Standards Institute (CLSI) document M24–A2 sug­gests using broth micro-dilution MIC determination. Agar tests and E-tests are not advised due to inconsistent ndings. M. fortuitum, M. peregrinum, M. chelonae, and M. abscessus are among the recommended strains. Amikacin, cefoxitin, ciprooxa­cin, clarithromycin, co-trimoxazole, doxycycline, imipenem, linezolid, moxioxa­cin, and tobramycin are medications that have been shown effective against rapidely growing bacteria (RGM). After 72h of incubation, micro-dilution trays should be tested at a temperature of 28 to 30 °C. The MIC should be recorded if there is growth in the growth control that is at least +2, else, re-incubate the tray and read on the fourth day. Repeat testing should be done if the growth on the fth day is insuf­cient. In the event that RGM does not improve after 6months of suitable antibiotic medication, it is required to conrm species identication and repeat susceptibility testing.