Detection of Nocardia, Streptomyces and Rhodococcus from broncho- alveolar lavage specimens of patients with HIV by Multiplex PCR Assay

Abstract

Background: Nocardia, Streptomyces and Rhodococcus are lifethreatening opportunistic pathogens under immunodeficiencyconditions, particularly among patients infected with HIV. Rapidand accurate detection of these infections can improve immunehealth quality, patient management and appropriate treatment. Theaim of this study was to design a novel multiplex-PCR assay forrapid diagnosis of these three organisms directly from broncho-alveolar lavage (BAL) specimens of patients infected with HIV.Methods: The genus specific primers were designed for direct-detection of Nocardia, Streptomyces and Rhodococcus in a singletube multiplex PCR. This PCR specifically amplified the targetgenes from pure cultures. It subsequently was applied on BALspecimens of 29 HIV positive patients that had previously beenculture negative for actinomycete bacteria, of which Nocardia,Streptomyces and Rhodococcus are members.Results: Of 29 respiratory clinical specimens, there were positivefor Nocardia spp. and one was positive for Streptomyces spp usingthe multiplex PCR assay. The sequencing of the PCR productsidentified the species as Nocardia cyriacigeorgica (n=2), Nocardiafarcinica and Streptomyces albus.Conclusion: This novel multiplex PCR assay yielded reliableresults for accurate identification of Nocardia, Streptomyces andRhodococcus from BAL while the results of bacterial culture werenegative.