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Pufferfish (Tetraodon cutcutia) Sampled from a Freshwater River Serves as an Intermediate Reservoir of a Sucrose Nonfermenting Variant of Vibrio cholerae PS-4.
- Source :
-
Microbiology spectrum [Microbiol Spectr] 2022 Feb 23; Vol. 10 (1), pp. e0122121. Date of Electronic Publication: 2022 Feb 16. - Publication Year :
- 2022
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Abstract
- We describe the genomic characteristics of Vibrio cholerae strain PS-4 that is unable to ferment sucrose on a thiosulfate citrate bile salt sucrose (TCBS) agar medium. This bacterium was isolated from the skin mucus of a freshwater pufferfish. The genome of strain PS-4 was sequenced to understand the sucrose nonfermenting phenotype. The gene encoding the sucrose-specific phosphotransferase system IIB (sucR) was absent, resulting in the defective sucrose fermenting phenotype. In contrast, genes encoding the glucose-specific transport system IIB (ptsG) and fructose-specific transport system IIB (fruA) showed acid production while growing with respective sugars. The overall genome relatedness indices (OGRI), such as in silico DNA-DNA hybridization ( is DDH), average nucleotide identity (ANI), and average amino acid identity (AAI), were above the threshold value, that is, 70% and 95 to 96%, respectively. Phylogenomic analysis based on genome-wide core genes and the nonrecombinant core genes showed that strain PS-4 clustered with Vibrio cholerae ATCC 14035 <superscript>T</superscript> . Further, genes encoding cholera toxin ( ctx ), zonula occludens toxin ( zot ), accessory cholera enterotoxin ( ace ), toxin-coregulated pilus ( tcp ), and lipopolysaccharide biosynthesis ( rfb ) were absent. PS-4 showed hemolytic activity and reacted strongly to the R antibody. Therefore, the Vibrio cholerae from the pufferfish adds a new ecological niche of this bacterium. IMPORTANCE Vibrio cholerae is native of aquatic environments. In general, V. cholerae ferments sucrose on thiosulfate citrate bile salt sucrose (TCBS) agar and produces yellow colonies. V. cholerae strain PS-4 described in this study is a sucrose nonfermenting variant associated with pufferfish skin and does not produce yellow colonies on TCBS agar. Genes encoding sucrose-specific phosphotransferase system IIB (sucR) were absent. The observed phenotype in the distinct metabolic pathway indicates niche-specific adaptive evolution for this bacterium. Our study suggests that the nonfermenting phenotype of V. cholerae strains on TCBS agar may not always be considered for species delineation.
- Subjects :
- Animals
Bacterial Proteins genetics
Bacterial Proteins metabolism
Cholera microbiology
Endotoxins metabolism
Fermentation
Fructose metabolism
Genome, Bacterial
Glucose metabolism
Humans
Phosphotransferases genetics
Phosphotransferases metabolism
Rivers microbiology
Skin microbiology
Vibrio cholerae genetics
Vibrio cholerae isolation & purification
Disease Reservoirs microbiology
Sucrose metabolism
Tetraodontiformes microbiology
Vibrio cholerae metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 2165-0497
- Volume :
- 10
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Microbiology spectrum
- Publication Type :
- Academic Journal
- Accession number :
- 35171023
- Full Text :
- https://doi.org/10.1128/spectrum.01221-21