Streptococcus suis (S. suis) is a capsular Gram-positive coccus that often colonizes the upper respiratory tract of pigs, and causes zoonotic diseases. Occupations susceptible to S. suis infection are pigs or pig by-products processors, such as butchers, farmers or cooks [1]. Some studies identified consumption of raw pork and presence of skin injuries while dealing with pigs or pig meat as independent risk factors for S. suis infections. S. suis can infect various systems, often causing fever, skin and mucous membrane bleeding and gastrointestinal symptoms. In severe cases, multiple organ dysfunction and septic shock may occur. The most common site of infection of S. suis is the central nervous system [2]. When it infects the central nervous system, it manifests as the typical symptoms of purulent meningoencephalitis. With increased intracranial pressure, patients show headache, papilledema, and other symptoms, and may have focal neurological damage in severe cases. Because of these nonspecific initial manifestations, it is easily misdiagnosis for pneumococcal meningitis (20 %) or Listeria monocytogenes meningitis (36 %) [3]. S. suis may cause serious consequences with rapid disease progression, therefore an early diagnosis and treatment is crucial for S. suis meningitis patients. However, the current routine microbiological tests are not satisfactory hurdling a correct diagnosis at first attempt. In contrast, metagenomic next-generation sequencing (mNGS) can detect the DNA sequence of microorganisms in cerebrospinal fluid (CSF), so this technology can detect various microorganisms, including rare ones [3]. mNGS is a promising and universal pathogen detection method which can be used for clinical diagnosis in patients with meningitis or encephalitis.

Here, we report a clinical case where CSF was examined by mNGS for a rapid diagnosis of “Streptococcus suis meningoencephalitis”. At present, the reports of mNGS to check for S. suis in CSF have been rare, but its benefits are obvious. The study was approved by the ethics committee of the First Affiliated Hospital of Fujian Medical University and publication of the clinical data was approved by the patient.