Production of N-acyl homoserine lactones by Chromobacterium haemolyticum KM2 isolated from the river water in Malaysia

Abstract

Quorum sensing (QS) is a term used to describe cell-to-cell communication that enables bacteria to orchestrate group behaviours according to density of bacterial cells. In Gram-negative bacteria, this signalling system is widely known to regulate a variety of different phenotypes such as antibiotic production and biofilm formation. In this study, we report the production of N-acyl homoserine lactones produced by Chromobacterium haemolyticum strain KM2, a bacterium isolated from a river water of a reserved tropical national park. Preliminary screening of QS activity using biosensor reporter assays indicated that C. haemolyticum strain KM2 produces both short- and long-chain AHLs. Analysis with high-resolution liquid chromatography-mass spectrometry (LC-MS/MS) analysis revealed the production of three AHLs by strain KM2: N-octanoyl-L-homoserine lactone (C8-HSL), N-dodecanoyl-L-homoserine lactone (C12-HSL), and N-3-oxo-dodecanoyl-L-homoserine lactone (OC12-HSL). This bacterial isolate also exhibited strong β-haemolytic activity. To the best of our knowledge, this is the first documentation of QS activity and multiple AHLs production by C. haemolyticum strain KM2.

Outbreak of Fatal Piglet Diarrhea Caused by Chromobacterium haemolyticum in China

“…Te growth and development of C. haemolyticum require moist water sources. Consequently, the geographical location and climate of Guangdong Province provide an ideal habitat for the reproduction of C. haemolyticum [6,15]. We also detected C. haemolyticum in the drinking water of other pig farms with unexplained diarrhea, and after changing the water source, the piglet diarrhea was controlled.…”

“…Chromobacterium haemolyticum (C. haemolyticum) was considered as a separate species, lacking violet pigmentation but demonstrating strong hemolysis on sheep blood agar plates [3]. C. haemolyticum has been isolated from a variety of water environments, such as rice roots, lakes, rivers, and sewage efuent [4][5][6]. Tere is evidence that C. haemolyticum is mainly transmitted through water sources, and some reports suggest that C. haemolyticum can cause pneumonia and sepsis in humans, and the patients in these cases have a history of wound exposure or contact with water sources, indicating that C. haemolyticum maybe an opportunistic pathogen [7,8].…”

Fatal piglets diarrhea caused by a novel Chromobacterium haemolyticum

“…Clinical trials and drug resistance analysis show that this novel Chromobacterium haemolyticum is a potential threat to humans and animals. The suitable conditions for the growth ofChromobacterium haemolyticum are near moist water sources, and the geographical location and climate of Guangdong Province are very suitable for the reproduction of Chromobacterium haemolyticum(Lima-Bittencourt, Costa, Barbosa, Chartone-Souza, & Nascimento, 2011;Priya et al, 2018). We also detected Chromobacterium haemolyticum in the drinking water of other pig farms with unexplained diarrhea, and after changing the water source, the piglet diarrhea was controlled.…”

“…(Han, Han, & Segal, 2008). C .haemolyticum has been isolated in a variety of water environments, such as rice roots, lakes, rivers, and sewage effluent (Kanamori et al, 2020;Priya, Sulaiman, How, Yin, & Chan, 2018;Zhou et al, 2016). There is evidence that C .…”