RESUMEN
BACKGROUND & OBJECTIVE: We report a new polymerase chain reaction (PCR) - restriction fragment length polymorphism (RFLP) assay using mycobacterial groES as a target to identify Mycobacterium avium and M. intracellulare in clinical samples. METHODS: The assay was standardized using M. avium and M. intracellulare standard strains obtained from ATCC and was tested with 45 M. avium-M. intracellulare complex (MAC) clinical isolates (Of which 31 were from HIV(+) individuals). The standard and clinical strains were typed with HPLC based mycolic acid fingerprinting. RESULTS: Three polymorphisms (BamHI, BstNI and HgaI) were identified for inter-species differentiation among standard strains; of which, only HgaI was found to be useful in clinical isolates. Of the 45 isolates, 25 were M. avium and 20 were M. intracelluare. MAC isolates, which could not be differentiated by HPLC analysis, were also typed by this method. INTERPRETATION & CONCLUSION: The use of mycobacterial groES as a PCR-RFLP target for M. avium and M. intracellulare is a simple and rapid method that can complement HPLC in their differentiation.
Asunto(s)
Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Secuencia de Bases , Cartilla de ADN/genética , ADN Bacteriano/genética , Genes Bacterianos , Chaperonina 10/genética , Proteínas de Choque Térmico/genética , Humanos , Mycobacterium avium/genética , Complejo Mycobacterium avium/genética , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Especificidad de la EspecieRESUMEN
Nocardiosis has been recognized in recent times as an unusual opportunistic infection associated with HIV. Bacteraemia due to this pathogen is even rarer and only few cases have been reported in the literature. We report here a case of pulmonary nocardiosis with bacteraemia, which was initially diagnosed as pulmonary tuberculosis. A high index of suspicion is required to diagnose this infection as the clinical presentation and radiographic features mimic pulmonary tuberculosis.
RESUMEN
A comparison of three methods of susceptibility testing was undertaken on 30 susceptible and 25 resistant strains of Mycobacterium tuberculosis to determine an acceptable in vitro definition of resistance of ofloxacin. The strains were tested by the proportion method on Lowenstein Jensen (L-J) and 7H11 media and also by the BACTEC radiometric method. Using a criterion of 1 per cent or more growth at a concentration of 2 mg/1, there was a 100 per cent agreement with the conventional MIC method by the proportion tests on L-J as well as on 7H11 media. The BACTEC radiometric method, at the same concentration, yielded 98 per cent agreement. Thus, any of these methods could be used depending upon the infrastructure available.