Case Report
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 26, 2022; 10(18): 6283-6288
Published online Jun 26, 2022. doi: 10.12998/wjcc.v10.i18.6283
Coinfection of Streptococcus suis and Nocardia asiatica in the human central nervous system: A case report
Ying-Ying Chen, Xin-Hong Xue
Ying-Ying Chen, Xin-Hong Xue, Department of Neurology, Liaocheng People’s Hospital, Liaocheng 252000, Shandong Province, China
Author contributions: Chen YY reviewed the literature, analyzed the patient data and wrote the manuscript; Xue XH and Chen YY were responsible for data collection; All the authors read and approved the final manuscript.
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 conflicts 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: Xin-Hong Xue, Doctor, Additional Professor, Department of Neurology, Liaocheng People’s Hospital, No. 67, Dongchang West Road, Liaocheng 252000, Shandong Province, China.
Received: December 17, 2021
Peer-review started: December 17, 2021
First decision: January 18, 2022
Revised: February 19, 2022
Accepted: April 21, 2022
Article in press: April 21, 2022
Published online: June 26, 2022

Streptococcus suis (S. suis) is an anthropozoonotic pathogen that shows clinical manifestations of meningitis, septicemia, and arthritis in infected humans. Nocardia is another type of anthropozoonotic bacteria, with clinical manifestations of skin, lung, and brain abscesses in infected humans. Few intracranial infections caused by S. suis or Nocardia have been reported. To the best of our knowledge, no study has reported a patient with simultaneous intracranial infection by S. suis and Nocardia.


A 66-year-old male presented at Liaocheng People’s Hospital (Liaocheng, Shandong Province, China) reporting dizziness with nausea and vomiting. Metagenomic next-generation sequencing (mNGS) was performed on cerebrospinal fluid for examination, and the patient was diagnosed with suppurative meningitis caused by S. suis infection. He received anti-infection treatment with penicillin sodium and ceftriaxone. The patient’s condition initially improved but then deteriorated. Further mNGS of cerebrospinal fluid revealed both S. suis and Nocardia. Imaging examination revealed a brain abscess. Furthermore, a mixed infection of S. suis and Nocardia was detected in the patient’s central nervous system. The patient was treated with antibiotics and sulfamethoxazole. He was discharged after his condition improved.


This case shows that the disease can be recurrent in patients with intracranial infection of a rare pathogen. The possibility of mixed infection should also be considered, especially in patients treated with immunosuppressive agents. mNGS of cerebrospinal fluid is a supplement to conventional microbial pathogen identification methods. Patients with unknown pathogen diagnosis, early extensive use of antibiotics and infection with rare pathogens can be diagnosed by the combination of conventional methods and mNGS of cerebrospinal fluid.

Keywords: Streptococcus suis, Nocardia, Meningitis, Brain abscess, Case report

Core Tip: Streptococcus suis (S. suis) meningitis is rare in the neurology department. S. suis combined with Nocardia is also rare, and intracranial infection of atypical pathogens is difficult to identify. Streptococcus cultivation requires high nutrition. In addition, the difficulty of cultivating S. suis makes the clinical identification more challenging and usually prolongs therapies. mNGS can be utilized to determine pathogens in the early phase of illness.