A new species of bacterium Pseudomonas trutticola sp. nov., isolated from rainbow trout farm in temperate northern Himalayan region of India

A novel bacterial species belonging to the genus Pseudomonas has been isolated from a trout farm in Uttarakhand by ICAR-Central Institute of Coldwater Fisheries Research, Bhimtal. The species has been designated Pseudomonas trutticola (trut.ti’co.la. L. n. trutta, trout; L. suff. -cola, dweller; N.L. fem. adj. trutticola, dwelling on trout). Notably, this bacterium could not be detected using universal primers targeting the 16S rRNA, rpoD, and gyrB genes, as no PCR amplicons were obtained. Identification was achieved through whole-genome sequencing (WGS).

The draft genome size of P. trutticola is 6,625,804 bp with a G+C content of 59 mol%. Unlike many Pseudomonas species, it does not exhibit fluorescence. Genomic analysis revealed 110 antimicrobial resistance (AMR) genes and 595 virulence-associated genes.

Phylogenomic analysis based on WGS data indicates that P. trutticola forms a distinct clade within the genus, showing closest similarity to Pseudomonas baetica (93%) and Pseudomonas tensinigenes ZA 5.3 (89%). Average Nucleotide Identity (ANI) values between P. trutticola and related species are below the 93% species demarcation threshold, and digital DNA–DNA hybridization (dDDH) values are below 70%, confirming its status as a novel species. The genome sequence of this bacterium has been submitted to GenBank (NCBI: BioProject ID PRJNA1348883; Biosample ID Submission: SUB15730266).

Colony of Pseudomonas trutticola in TSA agar plate, when incubated at 28°C for 48 h. The colony is mucoid and translucent. 

Gram-stain of Pseudomonas trutticola, shows that the bacterium is non chain forming Gram-negative rod.

This discovery was made possible by a team of scientists from ICAR-CICFR, Bhimtal namely Dr Neetu Shahi, Dr Krishna Kala, Mr Sumanta K. Mallik, Mr Bhupendra Singh, Dr Amit Pande and Dr Suresh Chandra. 

(Source: ICAR-Central Institute of Coldwater Fisheries Research, Bhimtal)