Elucidating the effect of cations onKlebsiella pneumoniaebiofilm and related genes

Abstract

AbstractK. pneumoniaeis a non-motile, encapsulated bacterium from the Enterobacteriaceae family. The illnesses related to this opportunistic pathogen are pneumonia, Urinary Tract Infection (UTI), pyogenic liver abscess, endophthalmitis, and meningitis. Among them, UTI is predominant due to its biofilm formation leading to the mortality of 150 million people worldwide. The function of monovalent and divalent ions onKlebsiellabiofilm, aside from physiochemical variables, remains unclear. Hence the present study was performed to analyze the role of K+, Ca2+, Na+, Mg2+, NH+4in biofilm formation and its influence on biofilm-related genes. Among the tested cations, K+and Ca2+yielded strong biofilm in clinical and environment isolates in pH between 6.5 to 9.5. Increasing Ca2+ions concertation reduced theKlebsiellabiofilm. When compared to the hypercalciuria condition (Ca2+level > 5 mM), 2.5 mM resulted in high biofilm mass. Cations concurrently enhanced the size of the capsule and cell density ofKlebsiellabut were not correlated with biofilm mass. Expression of the LPS gene (WbaG) either in planktonic or biofilm stage promoted biofilm formation in the presence of K+, Ca2+and Na+. Whereas, expression of fimbriae genes (FimHandmrkD) was co- regulation, and capsule genes (RmpAandWcab) were absent. Stating, the primary component needed for theKlebsiellabiofilm is not the capsule or fimbriae, rather LPS. Resulting as a potent target in the treatment ofKlebsiellabiofilm in UTI. To the best of our knowledge, this is the first kind of study on the effect of cation ions on biofilm and planktonic cells ofKlebsiellaspp. and demonstrating the role of LPS biosynthesis gene (WbaG) in biofilm development.