Short Chain N-Acylhomoserine Lactone Production by Clinical Multidrug Resistant Klebsiella pneumoniae Strain CSG20

Abstract

Klebsiella pneumoniae is one of the most common Gram-negative bacterial pathogens in clinical practice. It is associated with a wide range of disorders, ranging from superficial skin and soft tissue infections to potentially fatal sepsis in the lungs and blood stream. Quorum sensing, or bacterial cell-cell communication, refers to population density-dependent gene expression modulation. Quorum sensing in Proteobacteria relies on the production and sensing of signaling molecules which are mostly N-acylhomoserine lactones. Here, we report the identification of a multidrug resistant clinical isolate, K. pneumoniae strain CSG20, using matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry. We further confirmed quorum sensing activity in this strain with the use of high resolution tandem liquid chromatography quadrupole mass spectrometry and provided evidence K. pneumoniae strain CSG20 produced N-hexanoyl-homoserine lactone (C6-HSL). To the best of our knowledge, this is the first report on the production of N-hexanoylhomoserine lactone (C6-HSL) in clinical isolate K. pneumoniae.

Quorum sensing activity of Citrobacter amalonaticus L8A, a bacterium isolated from dental plaque

“…The target plate was then subjected to automated MALDI Biotyper bench-top mass spectrometer using FlexControl software version 3.3. Bruker MALDI Biotyper Real Time Classification (RTC) (Version 3.1) software was implemented to analyze the generated spectra by standard pattern matching with default settings and identification was provided with score value 46 . In addition, the score-oriented dendrogram was constructed using MALDI Biotyper MSP creation method.…”

“…Mobile phases A and B used in this study were water and acetonitrile (both mobile phases added with 0.1% v/v formic acid), respectively with an initial ratio of 80:20. The parameters included flow rate, temperature were set as described previously 46 51 . The precursor ion scan mode will scan through m/z value from 150 to 400 and target the m/z 102 [M+H] + product ion which is the characteristic of the lactone ring moiety and indicates the presence of AHL.…”

Quorum Sensing Activity in Pandoraea pnomenusa RB38

“…MALDI-TOF MS analysis and 16S rDNA nucleotide sequencing was performed as described previously [12,18–20]. Nucleotide comparison was performed using the BLASTN program in the NCBI database and the phylogenetic tree was constructed using Molecular Evolutionary Genetic Analysis (MEGA).…”

Dielectrophoresis for Biomedical Sciences Applications: A Review

“…Conventionally, there a several methods available for bacterial identification such as staining, chromogenic agar, differential media, enzyme-based reaction or biochemical reaction methods for example indole, motility, Voges Proskauer (VP), methyl red, and citrate, matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry, enzyme linked immunoassay (ELISA) and polymerase chain reaction (PCR) methods [144,145,146,147,148,149,150,151]. These methods have been practiced in many pathology laboratories from local to central and specialized laboratories.…”