Case Report
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Apr 26, 2024; 12(12): 2079-2085
Published online Apr 26, 2024. doi: 10.12998/wjcc.v12.i12.2079
Overlapping infections of Mycobacterium canariasense and Nocardia farcinica in an immunocompetent patient: A case report
Hai-Yan Huang, Kun-Peng Bu, Jin-Wei Liu, Jing Wei
Hai-Yan Huang, Kun-Peng Bu, Jing Wei, Department of Comprehensive Internal Medicine, The Affiliated Cancer Hospital of Guangxi Medical University, Nanning 530021, Guangxi Zhuang Autonomous Region, China
Jin-Wei Liu, Department of Doppler Ultrasound, The Second Nanning People's Hospital, Nanning 530021, Guangxi Zhuang Autonomous Region, China
Author contributions: Huang HY and Wei J substantial contribution to the conception and design of the work; Huang HY, Wei J, Bu KP and Liu JW contribution to the acquisition, analysis, interpretation of data for the work; Huang HY contribution to article writing and revising; Bu KP and Wei J agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All authors have read and approve the final manuscript and contributed to the conception and design of the work.
Supported by The Guangxi TCM Suitable Technology Development and Promotion Project, No. GZSY20-20.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Jing Wei, Doctor, Department of Comprehensive Internal Medicine, The Affiliated Cancer Hospital of Guangxi Medical University, No. 71 Hedi Road, Nanning 530021, Guangxi Zhuang Autonomous Region, China.
Received: November 11, 2023
Revised: February 26, 2024
Accepted: April 2, 2024
Published online: April 26, 2024

Infections by non-tuberculous mycobacteria (NTM) have become more common in recent years. Mycobacterium canariasense (M. canariasense) was first reported as an opportunistic pathogen in 2004, but there have been very few case reports since then. Nocardia is a genus of aerobic and Gram-positive bacilli, and these species are also opportunistic pathogens and in the Mycobacteriales order. Conventional methods for diagnosis of NTM are inefficient. Metagenomic next-generation sequencing (mNGS) can rapidly detect many pathogenic microorganisms, even rare species. Most NTM and Nocardia infections occur in immunocompromised patients with atypical clinical symptoms. There are no previous reports of infection by M. canariasense and Nocardia farcinica (N. farcinica), especially in immunocompetent patients. This case report describes an immunocompetent 52-year-old woman who had overlapping infections of M. canariasense, N. farcinica, and Candida parapsilosis (C. parapsilosis) based on mNGS.


A 52-year-old woman presented with a productive cough and chest pain for 2 wk, and recurrent episodes of moderate-grade fever for 1 wk. She received antibiotics for 1 wk at a local hospital, and experienced defervescence, but the productive cough and chest pain persisted. We collected samples of a lung lesion and alveolar lavage fluid for mNGS. The lung tissue was positive for M. canariasense, N. farcinica, and C. parapsilosis, and the alveolar lavage fluid was positive for M. canariasense. The diagnosis was pneumonia, and application of appropriate antibiotic therapy cured the patient.


Etiological diagnosis is critical for patients with infectious diseases. mNGS can identify rare and novel pathogens, and does not require a priori knowledge.

Keywords: Overlapping infection, Mycobacterium canariasense, Nocardia farcinica, Metagenomic next-generation sequencing technology, Case report

Core Tip: Non-tuberculous mycobacteria (NTM) and Nocardia are opportunistic pathogens that can occur in immunocompromised patients who present with atypical clinical symptoms. Mycobacterium canariasense (M. canariasense) is a rare NTM species was first identified 20 years ago. We describe a patient with multiple lung nodules of unequal size with uneven internal density, and multiple small burrs at the edges of these lung lesions. The pathology results were inconsistent with malignancy, and metagenomic next-generation sequencing indicated overlapping infections of M. canariasense, Nocardia farcinica, and Candida parapsilosis. The anti-infective treatment was successful.