Introduction: Nocardia is saprophytic soil bacterium of the actinomycetes families. Nocardia has high diversity of species and due to species diversity of Nocardia, phenotypic tests are essential for early identification of Nocardia species.
Methods: 155 soil samples from different regions of North Khorasan province in Iran were collected, including: urban and rural areas. Isolation of Nocardia was performed by paraffin baiting Technique. Identification of Nocardia species was performed by phenotypic methods that are including: hydrolysis of the amino acids, acid production of carbohydrates and, growth at 35° C and 45°C.
Results: 11 Nocardia species (7%) were identified . These bacteria were related to the gardens, the sands soils, and soil of town square. No growth was observed at 45°C. As the result, our isolates were identified as Nocardia asteroides complex.
Conclusion: Isolation and identification of Nocardia spp. from soil of different regions in North Khorasan province in Iran can help to enhance our understanding of epidemiological and ecological of the pathogenic Nocardia species.