TY - JOUR

T1 - The Symbiotic Bacterium Serratia liquefaciens Enhances the Development of Bacillus thuringiensis Bacteriosis in Colorado Potato Beetle Larvae by Alkalization of pH in the Midgut

AU - Artemchenko, A. S.

AU - Klementeva, T. N.

AU - Khodyrev, V. P.

AU - Sitnikov, V. N.

AU - Glupov, V. V.

AU - Polenogova, O. V.

PY - 2025/5/5

Y1 - 2025/5/5

N2 - Abstract: Invasion by pathogens is accompanied by competitive interactions between the pathogens and the microbiota, by the allocation of a niche in the intestine for the pathogen, and induction of immune processes in the host organism. These processes are accompanied by the accumulation of microbiota secondary metabolites, which may result in alterations of physicochemical characteristics of the host gut. These events may affect the speed of progression of bacterial infections, including secondary bacterial infections. In this study, experimental evidence showed that within the initial 24-h period, both in vitro and in vivo, interaction between Bacillus thuringiensis (Bt) and the symbiotic bacterium Serratia liquefaciens caused alkalization of the medium: both the culture fluid and the midgut contents of the Colorado potato beetle (CPB). Combined oral administration of S. liquefaciens and Bt resulted in 83% mortality of CPB larvae as early as 48 h after the inoculation. This mortality rate was 8.3-fold higher than that (≤10%) observed in individuals infected with Bt alone. Provision of food treated with Bt and a peptide fraction of S. liquefaciens metabolites to CPB larvae had analogous synergistic effects on mortality. It is possible that during an invasion by pathogens under conditions of the gut microbiota, there is an increase in the production of metabolites that can result in a release of inhibitors into the local medium. These inhibitors may then act as activators of Bt endotoxins (Cry toxins). This hypothesis requires further research.

AB - Abstract: Invasion by pathogens is accompanied by competitive interactions between the pathogens and the microbiota, by the allocation of a niche in the intestine for the pathogen, and induction of immune processes in the host organism. These processes are accompanied by the accumulation of microbiota secondary metabolites, which may result in alterations of physicochemical characteristics of the host gut. These events may affect the speed of progression of bacterial infections, including secondary bacterial infections. In this study, experimental evidence showed that within the initial 24-h period, both in vitro and in vivo, interaction between Bacillus thuringiensis (Bt) and the symbiotic bacterium Serratia liquefaciens caused alkalization of the medium: both the culture fluid and the midgut contents of the Colorado potato beetle (CPB). Combined oral administration of S. liquefaciens and Bt resulted in 83% mortality of CPB larvae as early as 48 h after the inoculation. This mortality rate was 8.3-fold higher than that (≤10%) observed in individuals infected with Bt alone. Provision of food treated with Bt and a peptide fraction of S. liquefaciens metabolites to CPB larvae had analogous synergistic effects on mortality. It is possible that during an invasion by pathogens under conditions of the gut microbiota, there is an increase in the production of metabolites that can result in a release of inhibitors into the local medium. These inhibitors may then act as activators of Bt endotoxins (Cry toxins). This hypothesis requires further research.

KW - Leptinotarsa decemlineata

KW - bioinsecticide

KW - biological control

KW - entomopathogenic bacterium

KW - microbiota

UR - https://www.mendeley.com/catalogue/c3c191bd-e6b2-30fb-b849-472938471092/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-105004345694&origin=inward&txGid=c07d1e75aa553710dfaa4f6ca42a4378

U2 - 10.1134/S0026261724609436

DO - 10.1134/S0026261724609436

M3 - Article

VL - 94

SP - 273

EP - 281

JO - Microbiology

JF - Microbiology

SN - 0026-2617

IS - 2

ER -