摘要：The aim of this multicenter study was to determine the genetic diversity and antibiotic susceptibility of clinically isolated Nocardia species. One hundred twenty-seven patients with nocardiosis were randomly selected from 5 provinces of Iran. Molecular diagnosis of Nocardia species was performed using multilocus sequence analysis of gyrase B of the β subunit of DNA topoisomerase ( gyrB ), and 16S rRNA and subunit A of SecA preproteintranslocase ( secA1 ). Antimicrobial susceptibility testing was performed following the Clinical and Laboratory Standards Institute recommendations. Thirty-five N. cyriacigeorgica , 30 N. asteroides , 26 N. farcinica , 12 N. otitidiscaviarum, and 10 N. abscessus cultures were studied. All isolates were susceptible to linezolid. All isolates of N. cyriacigeorgica , N. asteroides, N. abscessus, and N. otitidiscaviarum were susceptible to trimethoprim-sulfamethoxazole, while 8% of N. farcinica isolates were resistant to this drug. All N. otitidiscaviarum isolates were highly resistant to imipenem, but N. cyriacigeorgica , N. asteroides, N. farcinica, and N. abscessus were only moderate resistant. The susceptibility patterns vary with different species of Nocardia . Resistance to trimethoprim-sulfamethoxazole in Iran is low and this drug should be first line therapy, unless drug susceptibility testing shows resistance. Linezolid also covers Nocardia well and could be a second line agent.
