Pseudocitrobacter corydidari sp. nov., isolated from the Asian emerald cockroach Corydidarum magnifica

Abstract

A Gram-negative bacterial strain, G163CM^T, was isolated from the gut of the Asian emerald cockroach Corydidarum magnifica. The 16S rRNA gene sequence (1416 bp) of strain G163CM^T showed 99.22% similarity to Pseudocitrobacter faecalis CCM 8479^T and Pseudocitrobacter vendiensis CPO20170097^T. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values of strain G163CM^T were 92.4, 48.8 and 95.7% to P. faecalis CCM 8479^T, and 93.3, 52.4 and 95.7% to P. vendiensis CPO20170097^T. This strongly supports the designation of G163CM^T as representing a new species in the genus Pseudocitrobacter. Phylogenetic trees based on the alignment of 16S rRNA, multilocus sequence analysis of six single-copy genes (fusA, pyrG, leuS, rpoB, recN and mnmE) and 107 core protein sequences consistently showed G163CM^T to be a member of the genus Pseudocitrobacter, closely related to P. vendiensis CPO20170097^T. In contrast to P. faecalis CCM 8479^T and P. vendiensis CPO20170097^T, the genome of G163CM^T did not encode for proteins conferring resistance to antibiotics. However, all three genomes encoded a similar number of virulence factors and specialized metabolite biosynthetic proteins. The major fatty acids of strain G163CM^T were C_16:0 (31.5 %), C_18:1 ω7c (22.6 %), C_17:0 cyclo (15.3 %) and C_14:0 (6.5 %). Based on the polyphasic results, we conclude that strain G163CM^T represents a novel species of the genus Pseudocitrobacter and we propose the name Pseudocitrobacter corydidari sp. nov. with the type strain G163CM^T (=DSM 112648^T=CCM 9160^T).

Keywords: Corydidarum magnifica; Enterobacteriaceae; Pseudocitrobacter corydidari; cockroach microbiome.