Humans and animals come into contact with various compounds in their natural environment. Most of the encountered substances are neutral, yet some may carry adverse health effects. The ingested food may be a source of harmful substances, including benzoquinones which, as shown by research results cited in this paper, demonstrate toxic, carcinogenic and enterotoxic activity. This group of compounds is inclusive of 2-methyl-1,4-benzoquinone (MBQ) and 2-ethyl-1,4-benzoquinone (EBQ), defensive secretions of the confused flour beetle (Tribolium confusum J. du V) and the red flour beetle (Tribolium castaneum Herbst). Benzoquinones have a carcinogenic effect, they are inhibitors of growth of various microorganisms, they produce a self-defense mechanism in threat situations and affect population aggregation. As noted by the referenced authors, the properties of benzoquinones have not been fully researched to this date.

A screen of bacteriophages infecting a panel of Campylobacter jejuni PT14 gene knock-out mutants identified a role for the minor flagellin encoded by the flaB gene, in the defense of the host against CP8unalikevirus bacteriophage CP_F1 infection. Inactivation of the flaB gene resulted in an increase in the susceptibility of PT14 cultures to infection by CP_F1 and an increase in bacteriophage yields. Infection of wild type PT14 with CP_F1 produces turbid plaques in bacterial lawns, from which 78% of the resistant isolates recovered exhibit either attenuation or complete loss of motility. CP_F1 produces clear plaques on the flaB mutant with no regrowth in the lysis zones. Complementation of the mutant restored overgrowth and the development of resistance at the expense of motility. Further analyses revealed an increase in bacteriophage adsorption constant of nearly 2-fold and burst-size 3-fold, relative to the wild type. Motility analysis showed no major reduction in swarming motility in the flaB mutant. Thus, we propose a new role for FlaB in the defense of campylobacters against bacteriophage infection.

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The present experiment was designed to demonstrate differences in the degree of fodder contamination with benzoquinones at various Tribolium confusum levels, the impact of infested feed on the beetle population and the impact of infested feed on the health status of rats.The feeding studies were done on female rats divided into 3 groups: a control group and two experimental groups. Experimental groups were fed with a fodder infested by 150 individuals of T. confusum per kg (group D1) and 300 individuals of T. confusum per kg (group D2). The insects were grown in the fodder for 5 months and the contaminated fodder was given to the laboratory animals for 8 weeks. After that period the rats were sacrificed, blood was drawn for morphological, biochemical and immunological analyses, as well as the samples of internal organs were taken for histopathology.Regardless of initial degree of infestation, after 5 months incubation period the content of benzoquinones in fodder reached the maximum level that reduced beetle population.The resulting concentration to benzoquinones had no effect upon feed intake nor growth of rate, whereas caused the presence of these substances in feces, urine and also in tissues which was indicated by pathological lesions observed in the study.The results obtained point to the possibility of the benzoquinones accumulation in the organisms of farm animals fed fodder containing pests.