title: First case report of pulmonary nocardiosis caused byNocardia mexicana.
abstract: BACKGROUND
  Nocardiaspecies usually cause opportunistic infections, and the frequency of these infections is increasing owing to the growing population of immunocompromised hosts. However,Nocardiaspecies may sometimes cause an infection disease in immunocompetent hosts.Nocardia mexicanainfections are the least common and are very rare.
  
  
  METHODS
  Herein, we report the first case of a pulmonary infection withN. mexicanain a 61-year-old Japanese woman with a history of hyperlipidaemia and bronchiectasis and a 6-month history of non-productive hacking cough. A sample of bronchial lavage fluid obtained by bronchofiberscopy showed filamentous branching gram-positive rods and acid-fast filamentous branching rods, and a colony of suspectedNocardiawas cultured. Based on 16S rRNA,gyrB,rpoB,secA1andhsp65gene sequence analyses and biochemical and physiological properties, the strain was identified asN. mexicana.The strain was resistant to the antimicrobial agents amoxicillin-clavulanic acid, clarithromycin, minocycline, gentamycin, tobramycin, ciprofloxacin and trimethoprim-sulfamethoxazole. The patient was treated with biapenem followed by intravenous amikacin and oral linezolid.
  
  
  CONCLUSIONS
  Despite its rarity, the species require attention owing to the existence of multidrug-resistant strains.
authors.affiliation: Department of Clinical Laboratory, Naga Municipal Hospital, 1282 Uchita, Kinokawa, Wakayama, 649-6414, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Kuchibiro
authors.affiliation: Department of Respiratory Medicine, Naga Municipal Hospital, 1282 Uchita, Kinokawa, Wakayama, 649-6414, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ikeda
authors.affiliation: Department of Respiratory Medicine, Naga Municipal Hospital, 1282 Uchita, Kinokawa, Wakayama, 649-6414, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Nakanishi
authors.affiliation: Department of Respiratory Medicine, Naga Municipal Hospital, 1282 Uchita, Kinokawa, Wakayama, 649-6414, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Morishita
authors.affiliation: Department of Clinical Laboratory, Naga Municipal Hospital, 1282 Uchita, Kinokawa, Wakayama, 649-6414, Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Houdai
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuoku, Chiba City, Chiba, 260-8673, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Ito
authors.affiliation: Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuoku, Chiba City, Chiba, 260-8673, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Gonoi
keywords: 16S rRNA; Nocardia mexicana; pulmonary nocardiosis