Broad spectrum antimicrobial compounds from the bacterium Exiguobacterium mexicanum MSSRFS9

Abstract

Clinical bacterial pathogens front a major challenge for the clinical researchers and physicians. In particular microbial pathogens like Escherichia coli, Shigella flexneri, Klebsiella pneumonia and Salmonella enterica are apparelled with systemic machineries to bring down the human immune system as well as proliferate dramatically in a short period which in turn cause a pronounced ailment to the human health. In vitro evaluation of four purified compounds isolated from rhizosphere bacterium Exiguobacterium mexicanum tested against clinical pathogens mentioned above by disc diffusion method showed the two compounds viz., 3,6,18-trione, 9,10-dihydro-12'-hydroxyl-2methyl-5-(phenyl methyl) (5'-alpha, 10-alpha)-dihydroergotamine (C3) and dipropyl - S-propyl ester (C4) exhibit antibacterial property against all the tested pathogens. Among the four clinical pathogens tested, compound C3 has shown higher zone of inhibition against S. enterica with 17±0 mm, followed by S. flexneri with 16.5±0.7 mm, E. coli with 15±0 mm and K. pneumoniae with 14±0 mm, respectively. The compound C4 has shown higher antimicrobial activity against S. enterica with 21.5±0.7 mm zone of inhibition, followed by S. flexneri with 19.5±0.7 mm, E. coli with 17±0 mm and K. pneumoniae with 16±0 mm, these two compounds were found to be safer when subjected to rat haematological and enzymatic analysis.

Bactericidal Effects of Exiguobacterium sp GM010 Pigment Against Food-Borne Pathogens

“…These results revealed, the isolated bacterium is belongs to the genus Exiguobacterium. Even though there are reports on Exiguobacterium species showing the algicidal (Li et al, 2016), antifungal (Selvakumar et al, 2009) and antibacterial (Shanthakumar et al, 2015) effect, there are no report on the antibacterial action of Exiguobacterium sp GM010 pigment and the mechanism of antibacterial action.…”

“…h10 mainly included carbonyl, amino, and hydroxyl groups (Li et al, 2016). Similarly 3,6,18-trione, 9,10-dihydro-12-hydroxyl-2methyl-5-(phenyl methyl) (5-alpha, 10-alpha)-dihydroergotamine and dipropyl-Spropyl ester molecules exhibit antibacterial action against clinical pathogens (Shanthakumar et al, 2015). The hydroxyl group of compounds and the presence of a system of delocalized electrons are important for the antimicrobial activity (Ultee et al, 2002).…”

“…The Streptomyces sp was widely studied microbial species from Indian coastal waters as a source of antibiotics (Chandramohan, 1997;Valliappan et al, 2014). There are report on the algicidal (Li et al, 2016), antifungal (Selvakumar et al, 2009) and antibacterial (Shanthakumar et al, 2015) effect of Exiguobacterium species, however mechanism of antibacterial effect of Exiguobacterium pigment on food-borne pathogens was not reported. In this study pigment producing Exiguobacterium sp GM010 was isolated, and characterized.…”

Whole-Genome Sequencing and Annotation of Exiguobacterium sp. RIT 452, an Antibiotic-Producing Strain Isolated from a Pond Located on the Campus of the Rochester Institute of Technology

“… Exiguobacterium is a genus of Gram-positive soil bacteria widely distributed in the environment, from tropical ( 1 ) to polar regions ( 2 ). A number of species have been sequenced and were shown to be extremophiles, such as hyperthermophiles, alkaliphiles, halophiles, and psychrophiles ( 2 – 4 ).…”

“…Other members of this genus have potential applications in the bioremediation of pesticides and metals and other applications in the biotechnology industry ( 5 – 11 ). One strain was found to produce antimicrobial compounds ( 1 ). A strain was isolated from the guts of mealworms, and it was shown that the bacterium was able to degrade the plastic polymer polystyrene ( 12 ).…”