Neuropharmacological Alterations by a Rice Contaminant Stenotrophomonas maltophilia: a Detailed Bio-molecular and Mechanistic Landscape.

Contaminated rice is a major source of food poisoning in human communities where our earlier study showed Stenotrophomonas maltophilia, a Gram-negative bacillus, has been a major contaminant of the stored rice. In the present study, mono- and di-unsaturated fatty acids (UFAs) such as 18:1 ω 7 c, 16:1 ω 6 c, 16:1 ω 7 c, and 18:2 ω 6,9 c long-chain fatty acids have been found as the chief constituents of S. maltophilia boiled cell lysate. Throughout the study, both acute and chronic exposure of the cell lysate showed a decrease in the locomotor activity and a time-dependent increase of the depression (p < 0.001-0.0001, two-way ANOVA), supported by bioamine (dopamine, noradrenaline, adrenaline, serotonin, and GABA) depletion in rodents' brain possibly due to UFA-amino acid decarboxylase interaction favoring bioamine depletion as revealed by our study. Furthermore, the UFA-rich cell lysate revealed dose-dependent inhibition of murine brain microglial cell viability in vitro with concomitant increase of reactive oxygen species (ROS) inside the cell. Destruction of neuroprotective and neurotrophin releasing microglial cells, augmentation of brain ROS, and inflaming brain tissue resulting in infiltration of polymorphonuclear leucocytes also suggest to cause neurotoxicity by UFA derived from Stenotrophomonas maltophilia.