Description of Streptococcus thalassemiae sp. nov., a Bacterium Isolated from Human Blood

Fatou Samba Diouf; Mamadou Beye; Mapenda Gaye; Babacar Mbaye; Stephane Alibar; Mariema Sarr; Gregory Dubourg; Jean-Christophe Lagier; Cheikh Sokhna; Florence Fenollar; Pierre-Edouard Fournier; Cheikh Ibrahima Lo

doi:10.1155/2023/3802590

Description of Streptococcus thalassemiae sp. nov., a Bacterium Isolated from Human Blood

Int J Microbiol. 2023 Aug 1:2023:3802590. doi: 10.1155/2023/3802590. eCollection 2023.

Authors

Fatou Samba Diouf^{1

2}, Mamadou Beye^{2

3}, Mapenda Gaye^{1

2}, Babacar Mbaye^{1

2}, Stephane Alibar^{1

2}, Mariema Sarr^{1

2}, Gregory Dubourg^{1

2}, Jean-Christophe Lagier^{1

2}, Cheikh Sokhna^{1

2

4}, Florence Fenollar^{2

3}, Pierre-Edouard Fournier^{2

3}, Cheikh Ibrahima Lo^{2

3}

Affiliations

¹ Aix Marseille University, IRD, AP-HM, MEPHI, Marseille, France.
² IHU-Mediterranean Infection, Marseille, France.
³ Aix Marseille University, IRD, AP-HM, SSA, VITROME, Marseille, France.
⁴ Campus Commun UCAD-IRD of Hann, Dakar, Senegal.

Abstract

Blood is a precious biological liquid that is normally sterile. Therefore, bacteria in the bloodstream are shown a priori anomaly. A blood culture is systematically performed to diagnose the cause of the bacteremia. Indeed, a patient received in our service had a thalassemia major and underwent a genoidentical transplant. Then, a blood test was performed to diagnose a four-day fever. In this context, we have isolated strain Marseille-Q2617 from the blood sample. It revealed a new bacterial strain that belongs to the genus Streptococcus. It is a Gram-positive coccus, nonmotile, and nonspore forming. The major fatty acid found is hexadecanoic acid, with 49.5%. A taxonomic method was used to characterize the strain by studying their phenotypic, phylogenetic, and genomic characteristics. In addition, sequence analysis of the 16S rRNA gene shows that the strain Marseille-Q2617 has 99.94% sequence similarity to Streptococcus mitis. Average nucleotide identity (ANI) analysis for strain Marseille-Q2617^T showed the highest similarity of 92.9% with S. mitis. The DNA-DNA hybridization value obtained (50.2%) between strain Marseille-Q2607 and S. mitis, its closest related species, was below the recommended threshold (<70%). Strain Marseille-Q2617^T has a genome size of 2.02 Mbp with 40.5 mol% of G + C content. Based on these results, we propose a new species of the genus Streptococcus, for which the name Streptococcus thalassemiae sp. nov., Marseille-Q2617^T (=CSUR Q2617 = CECT 30109) was proposed.