INHIBITION OF BACTERIAL QUORUM SENSING BY THE RUMINAL FLUID OF CATTLE

Authors

  • Karimov Il' shat
  • Duskaev Galimzhan
  • Inchagova Kseniya
  • Kartabaeva Madina

Keywords:

Ruminal fluid, Homoserine lactone, Bioluminescence, Quorum sensing inhibitor

Abstract

Rumen fluid contains factors that inactivate autoinducers, monitor microflora development
and prevent the mobilization of virulence properties, and thus, the formation of resistant bacteria. The aim of
this study was to assess the ability of rumen fluid to suppress the intercellular communication of bacteria by
inactivating the N-acyl-homoserine lactones. We used strains of luminescent Escherichia coli JLD271 which
were transformed with plasmids containing quorum sensing genes and luminescence genes. Bacteria were
cultivated in LB agar medium containing 10 ug/ml doxycycline then in LB medium until the early
exponential growth phase. The autoinducers used were N-butyryl-L-homoserine lactone (C4-HSL), N-(3-
oxo)-hexanoyl-L-homoserine lactone (oxo-С6-HSL) and N-dodecanoyl-L-homoserine lactone (C12-HSL).
The ruminal fluid of young calves was collected via a fistula. Equal volumes of ruminal fluid and
autoinducers were incubated then added to the cultures of luminescent bacterial strains. Dilution of the
ruminal fluid up to 12.5% did not affect the luminescence of the bacterial biosensors. Incubation of ruminal
fluid with N-acyl-homoserine lactones decreased their activity, marked by unexpressed specificity. The most
effective inhibition of the N-(3-oxo)-hexanoyl-L-homoserine lactone was observed at 10-7 M, and above this
concentration the efficiency of quorum sensing inhibition decreased. Ruminal fluid was able to inactivate Nacyl-homoserine lactones, and the efficiency of inhibition was not related to the length of the alkyl tail in the
signal molecule. This suggests the ability of the ruminant digestive system to control bacteria by the
inactivation of N-acyl-homoserine lactones, which regulate the quorum sensing system.

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Published

2017-09-15

How to Cite

Karimov Il’ shat, Duskaev Galimzhan, Inchagova Kseniya, & Kartabaeva Madina. (2017). INHIBITION OF BACTERIAL QUORUM SENSING BY THE RUMINAL FLUID OF CATTLE. GEOMATE Journal, 13(40), 88–92. Retrieved from https://geomatejournal.com/geomate/article/view/1373