Mycobacteria multidrug resistance

Capreomycin is a peptide protein synthesis inhibitor antibiotic obtained from Streptomyces capreolus. Daily injection of 1 g intramuscularly results in blood levels of 10 mcg/mL or more. Such concentrations in vitro are inhibitory for many mycobacteria, including multidrug-resistant strains of M tuberculosis. 

Treatment problems that can arise are mainly of two types adverse reactions (collateral, toxic, or hypersusceptibility reactions), and initial or acquired resistance of Mycobacterium tuberculosis, Mycobacterium bovis, or non-tuberculous mycobacteria to one or more of the antituberculosis drugs. The latter probably only occurs when the patient has not taken the full combination or the full doses of the drugs all the time. Combination formulations are thus particularly useful. Multidrug-resistant tuberculosis, defined as resistance against at least isoniazid and rifampicin, is the most clinically relevant form of resistance to treatment worldwide. 

Multidrug-resistant tuberculosis generally results from inadequate therapy or lack of compliance with therapy. A strain of mycobacteria is called resistant when it is insensitive to one of the first-line drugs. It is called multiresistant when it is insensitive to both isoniazid and rifampicin. In this case other antituberculosis drugs may also be ineffective (35). In practice, at least two second-line antituberculosis drugs, selected on the basis of individual drug susceptibility, are given in combination with a fluoroquinolone (36). 

In addition to the three discussed above, there are a number of other pathogens within the mycolata. Infections by non-TB mycobacteria including M. avium-intracellulare, M. marinum M. ulcerans, and M. kansasii are rarely seen in healthy individuals, but are common sources of skin infections and lung disease in AIDS patients [297]. In addition, there are increasing reports of human infections caused by multidrug-resistant non-diphtheria Corynebacteria, especially in immunocompromised patients [298,299]. 

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