Identification and genomic analyses of a Streptococcus suis ST25 strain associated with the first human septicemia in mainland China
Peipei Cao,
Meixing Lin,
Zhiling Chen,
Guannan Zhang,
Xin-He Lai,
Xiang Wu,
Lina Niu
Affiliations
Peipei Cao
Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, Hainan, China; Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Haikou, Hainan, China; Department of Pathogen Biology, School of Basic Medical Sciences and Life Sciences, Hainan Medical University, Haikou, Hainan, China
Meixing Lin
Hainan Provincial Hospital of Traditional Chinese Medicine, Haikou, Hainan, China
Zhiling Chen
Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, Hainan, China; Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Haikou, Hainan, China; Department of Pathogen Biology, School of Basic Medical Sciences and Life Sciences, Hainan Medical University, Haikou, Hainan, China
Guannan Zhang
Hainan Medical University Public Research Center, Haikou, Hainan, China
Xin-He Lai
Shenzhen Boya Gene Technology Company Limited, Shenzhen, China
Xiang Wu
Hainan Provincial Hospital of Traditional Chinese Medicine, Haikou, Hainan, China; Corresponding author.
Lina Niu
Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, Hainan, China; Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Haikou, Hainan, China; Department of Pathogen Biology, School of Basic Medical Sciences and Life Sciences, Hainan Medical University, Haikou, Hainan, China; Corresponding author. Hainan Medical College, No. 3 Xueyuan Road, Longhua District, Haikou, Hainan, China.
Streptococcus suis (S. suis) is a Gram-positive bacterium and the main culprit behind zoonotic outbreaks, posing a serious threat to public health. The prevalent strains in China are mainly of sequence types (ST) 1 and 7, with few cases of human infections caused by other sequence type being reported. This study presents the first isolation of a ST25 strain from the blood of a septicemic patient. A 57-year-old febrile patient was admitted to a hospital in Hainan of China, diagnosed as septicemia and hepatic dysfunction. A strain of S. suis was isolated from blood culture and confirmed to be serotype 2 and ST25 through 16S rRNA sequencing and whole-genome sequencing, and its genome was further analyzed for gene functions and presence of drug resistance genes. The full-length genome of strain HN28 spans 2,280,124 bp and encodes a total of 2291 proteins. Genes annotated in COG, GO, KEGG, CAZy, and PHl databases accounted for 75.38 %, 69.14 %, 55.35 %, 4.58 %, and 11.87 % of the total predicted proteins, respectively. Virulence factor analysis revealed the presence of seven putative virulence genes in strain HN28. Analysis using the CARD database identified 51 resistance genes in HN28, alongside abundant exocytosis systems. These findings underscore the occurrence of S. suis infections in humans caused by less common ST, emphasizing the need for enhanced epidemiological investigations and monitoring of S. suis infections in the human population.
