Effects of Antibody Induced Localized Cell Crowding on Autoinducer-2 Levels in Salmonella typhimurium LT2

Abstract

Cell-cell communication in bacteria such as Salmonella typhimurium LT2 is mediated by quorum sensing. The mechanism involves the synthesis and subsequent increase in the extracellular concentration of molecules called autoinducers as bacterial population density increases. Effects on autoinducer levels caused by antibody induced localized cell crowding of Salmonella typhimurium in liquid culture were studied. The Vibrio harveyi bioluminescence assay system was used to measure the amount of autoinducer present in the cell-free supernatant of treated Salmonella typhimurium cultures. The data suggested that antibody mediated cell crowding caused a decrease in autoinducer level. This effect was consistent with artificial crowding experiments that did not utilize antibodies.