Clinical characteristics of Nocardia infection and drug resistance

OBJECTIVE To investigate the clinical characteristics of Nocardia infection, specimens sources and drug resistance so as to provide guidance for reasonable clinical use of antibiotics.METHODS The Nocardia strains that were isolated from Jan 2012 to Mar 2017 were retrospectively analyzed, the distribution of species, specimens sources, clinical characteristics and results of drug susceptibility testing were observed, the strains were amplified, sequenced and identified by using 16S rRNA, and the in vitro drug susceptibility testing was performed with the use of micro broth dilution method.RESULTS Totally 15 strains of Nocardia were collected, including 3 species, 66.7% of which were Nocardia cyriacigeorigica,20.0% were Nocardia farcinica,and 13.3% were Nocardia otitidiscaviarum. Of the specimens sources, 46.5% were sputum specimens, and 20.0% were venous blood specimens. The respiratory system, skin and central nervous system were involved, the pulmonary infection was the major clinical manifestation and was characterized by cough, expectoration and fever. The drug resistance rate of the Nocardia strains to ciprofloxacin was the highest (80.0%),followed by gentamicin (26.7%). The drug susceptibility rates of all the strains to amikacin, clarithromycin, linezolid and sulfamethoxazole-trimethoprim were 100.0%, and the strains were highly susceptible to imipenem and minocycline.CONCLUSION The Nocardia strains are highly susceptible to linezolid and macrolides as well as sulfonamides but are less susceptible to quinolones. It is necessary to strengthen the surveillance of drug resistance so as to provide theoretical bases for reasonable clinical use of antibiotics and control of nosocomial infection.