Isolation, biochemical and molecular identification of Nocardia species among TB suspects in northeastern, Tanzania; a forgotten or neglected threat?
نویسندگان
چکیده
BACKGROUND Pulmonary nocardiosis mimic pulmonary tuberculosis in most clinical and radiological manifestations. In Tanzania, where tuberculosis is one of the major public health threat clinical impact of nocardiosis as the cause of the human disease remains unknown. The objective of the present study was to isolate and identify Nocardia isolates recovered from TB suspects in Northeastern, Tanzania by using biochemical and molecular methods. METHODS The study involved 744 sputum samples collected from 372 TB suspects from four periphery diagnostic centers in Northeastern, Tanzania. Twenty patients were diagnosed as having presumptively Nocardia infections based on microscopic, cultural characteristics and biomèrieux ID 32C Yeast Identification system and confirmed using 16S rRNA and hsp65 gene specific primers for Nocardia species and sequencing. RESULTS Biochemically, the majority of the isolates were N. asteroides (n = 8/20, 40%), N. brasiliensis (n = 4/20, 20%), N. farcinica (n = 3/20, 15%), N. nova (n = 1/20, 5%). Other aerobic actinomycetales included Streptomyces cyanescens (n = 2/20, 10%), Streptomyces griseus, Actinomadura madurae each (n = 1/20, 5%). Results of 16S rRNA and hsp65 sequencing were concordant in 15/17 (88. 2%) isolates and discordant in 2/17 (11.8%) isolates. Majority of the isolates belonged to N. cyriacigeorgica and N. farcinica, four (23.5%) each. CONCLUSIONS Our findings suggest that Nocardia species may be an important cause of pulmonary nocardiosis that is underdiagnosed or ignored. This underscores needs to consider pulmonary nocardiosis as a differential diagnosis when there is a failure of anti-TB therapy and as a possible cause of human infections.
منابع مشابه
Comparison of Three Methods of Isolation of the Genus Nocardia from the Soil of Hospitals in Isfahan Province, Iran, and its Identification Based on Phenotypic and Molecular Methods
Background & Aims: Nocardia are gram-positive, aerobic, relative acid-fast, and opportunistic bacteria, and one of the causes of systematic infection around the world. The natural habitats of these bacteria are soil and dust. Hospitalized patients with immune deficiency are at high risk of transmission of opportunistic infection. Due to these facts and the complexities that exist in the isolati...
متن کاملComparison of Three Methods of Isolation of the Genus Nocardia from the Soil of Hospitals in Isfahan Province, Iran, and its Identification Based on Phenotypic and Molecular Methods
Background & Aims: Nocardia are gram-positive, aerobic, relative acid-fast, and opportunistic bacteria, and one of the causes of systematic infection around the world. The natural habitats of these bacteria are soil and dust. Hospitalized patients with immune deficiency are at high risk of transmission of opportunistic infection. Due to these facts and...
متن کاملComparative of phenotypic tests in aerobic actinomycetes
Dear editor,I read with interest article that published entitled *Isolation and identification of bioactive compound producing Rhodococcus spp. isolated from soil samples {IJMCM/5(1) (2015) 463-468}* [1]. Some of the genus such as Nocardia, Gordonia, Mycobacterium and Rhodococcus are in actinomycete family and they are Gram-positive and partially acid-fast. Rhodococcus species usually stain Gra...
متن کاملDetection of Nocardia Asteroides Complex in Clinical Isolates by Real-Time Polymerase Chain Reaction
Background and Aims: Nocardia asteroides complex is the most common cause of infectious diseases due to nocardiosis. Interspecies differentiation of Nocardia genera is essential for prognosis and timely proper treatment, as well as for epidemiological studies. Since each genus has its own antibiotic resistance, precise careful diagnosis is of prime importance. As compared to biochemical and phe...
متن کاملThe Comparison of Biochemical and Sequencing 16S rDNA Gene Methods to Identify Nontuberculous Mycobacteria
The identification of Mycobacteria in the species level has great medical importance. Biochemical tests are laborious and time-consuming, so new techniques could be used to identify the species. This research aimed to the comparison of biochemical and sequencing 16S rDNA gene methods to identify nontuberculous Mycobacteria in patients suspected to tuberculosis in Golestan province which is the ...
متن کامل