Network analysis identifies a shared flagellar-associated candidate module in five selected Gram-negative pathogen strains

YITAO XIANG (School of Pharmaceutical Science, Hengyang Medical College, University of South China. Changsheng West Road, Hengyang 421001, Hunan, China)
XIAOCHAN LIU (First Affiliated Hospital, Hunan Provincial Clinical Medical Research Center for Drug Evaluation of Major Chronic Diseases, Hengyang Medical School, University of South China. Hengyang 421001, Hunan, China)
LI YU (School of Pharmaceutical Science, Hengyang Medical College, University of South China. Changsheng West Road, Hengyang 421001, Hunan, China)
FANGZHEN LUO (School of Pharmaceutical Science, Hengyang Medical College, University of South China. Changsheng West Road, Hengyang 421001, Hunan, China)

Nusantara Bioscience
Vol. 18 No. 2 (2026)

Abstract. Xiang Y, Liu X, Yu L, Luo F. 2026. Network analysis identifies a shared flagellar-associated candidate module in five selected Gram-negative pathogen strains. Nusantara Bioscience 18 (2): n180202. https://doi.org/10.13057/nusbiosci/n180202. We compared score-filtered STRING functional-association networks from five selected flagellated Gram-negative pathogen reference strains: Burkholderia cenocepacia J2315, Enterobacter cloacae ATCC 13047, Escherichia coli JJ1886, Legionella pneumophila Philadelphia 1, and Pseudomonas aeruginosa UCBPP-PA14. Here, shared denotes an exact normalized node label present in all five networks and does not imply formal orthology. The five connected networks contained 51, 94, 157, 117, and 222 nodes. Their exact five-way connected-node intersection comprised 20 labels, and the same 20 were recovered from the full filtered-node sets. The raw preferred-name intersection expanded to 21 only because one Burkholderia flhA mapping referred to a non-flagellar alcohol dehydrogenase annotation. Under a within-network top-decile rule, only flgG and fliM were shared-central across all five networks. A within-species MMseqs2 audit across five fixed 50-assembly panels showed broad presence of the primary 20 labels and little change after restriction to strict ANI-pass assemblies. The selected-reference fliC label remained detectable in 50/50, 50/50, 47/50, 50/50, and 50/50 assemblies, yet a broader flagellin-family audit revealed marked cross-species heterogeneity, so shared label identity was not interpreted as molecular equivalence. The historical 18-protein set was retained only as secondary conditional STRING-coherence evidence. Because the study includes only five selected flagellated pathogen strains and no commensal, non-pathogenic, or non-flagellated controls, the results support a hypothesis-generating shared flagellar/motility-associated module rather than a pathogen-specific core.