Métodos de determinación de sensibilidad a los antimicrobianos en micobacterias / Methods for determining the antimicrobial susceptibility of mycobacteria

Las micobacterias son un amplio grupo de microorganismos en el que múltiples especies son causa de una importante morbimortalidad, como la tuberculosis y la lepra. La aparición y diseminación de cepas del complejo Mycobacterium tuberculosis resistentes a diversos fármacos constituye en la actualidad uno de los problemas sanitarios de mayor gravedad a nivel mundial. Por otro lado, las micobacterias diferentes de M. tuberculosis y Mycobacterium leprae, denominadas micobacterias no tuberculosas (MNT), son aislamientos cada vez más frecuentes, requiriendo en muchos casos un tratamiento que precisa una orientación sobre la sensibilidad de estos microorganismos a los antimicrobianos. En el presente artículo se revisan los métodos para determinar la sensibilidad in vitro a los antimicobacterianos de los aislamientos del complejo M. tuberculosis y las MNT más relevantes. Además, también se realiza un análisis de las técnicas moleculares de detección rápida de la resistencia a partir de las muestras clínicas (AU)

Mycobacteria are a large group of microorganisms, multiple species of which are major causes of morbidity and mortality, such as tuberculosis and leprosy. At present, the emergence and spread of multidrug-resistant strains of Mycobacterium tuberculosis complex are one of the most serious health problems worldwide. Furthermore, in contrast to M. tuberculosis and Mycobacterium leprae, non-tuberculous mycobacteria (NTM) are more frequently isolated and, in many cases, treatment is based on drug susceptibility testing. This article is a review of the different methods to determine the in vitro drug susceptibility of M. tuberculosis complex and the most relevant NTM isolates. The molecular techniques currently used for rapid detection of resistance of clinical specimens are also analysed (AU)

Methods for determining the antimicrobial susceptibility of mycobacteria. / Métodos de determinación de sensibilidad a los antimicrobianos en micobacterias.

Mycobacteria are a large group of microorganisms, multiple species of which are major causes of morbidity and mortality, such as tuberculosis and leprosy. At present, the emergence and spread of multidrug-resistant strains of Mycobacterium tuberculosis complex are one of the most serious health problems worldwide. Furthermore, in contrast to M. tuberculosis and Mycobacterium leprae, non-tuberculous mycobacteria (NTM) are more frequently isolated and, in many cases, treatment is based on drug susceptibility testing. This article is a review of the different methods to determine the in vitro drug susceptibility of M. tuberculosis complex and the most relevant NTM isolates. The molecular techniques currently used for rapid detection of resistance of clinical specimens are also analysed.

[Cutaneous and soft skin infections due to non-tuberculous mycobacteria]. / Infecciones cutáneas y de partes blandas por micobacterias no tuberculosas.

The frequency of isolation as well as the number of species of non-tuberculous mycobacteria (NTM) has increased in the last years. Nearly every pathogenic species of NTM may cause skin and soft tissue infections, but rapidly growing mycobacteria (Mycobacterium fortuitum, Mycobacterium chelonae and Mycobacterium abscessus), Mycobacterium marinum and Mycobacterium ulcerans are the most commonly involved. Many of these cutaneous mycobacteriosis, such as rapidly growing mycobacteria, M. marinum, Mycobacterium avium complex, Mycobacterium kansasii or Mycobacterium xenopi are world-wide distributed. In contrast, some others have a specific geographical distribution. This is the case of M. ulcerans, which causes a cutaneous diseases endemic of Central and West Africa (Buruli ulcer) and Australia (Bairnsdale ulcer), being the third mycobacterial infection after tuberculosis and leprosy. Cutaneous mycobacteriosis usually appear either after contact of traumatic or surgical wounds with water or other contaminated products, or, secondarily, as a consequence of a disseminated mycobacterial disease, especially among immunosuppressed patients. For an early diagnosis, it is necessary to maintain a high degree of suspicion in patients with chronic cutaneous diseases and a history of trauma, risk exposure and negative results of conventional microbiological studies. In general, individualized susceptibility testing is not recommended for most NTM infections, except for some species, and in case of therapeutic failure. Treatment includes a combination of different antimicrobial agents, but it must be taken into account that NTM are resistant to conventional antituberculous drugs. Severe cases or those with deep tissues involvement could also be tributary of surgical resection.