scholarly journals Quorum sensing modulatory effect of sound stimulation on Serratia marcescens and Pseudomonas aeruginosa

2016 ◽  
Author(s):  
Vijay Kothari ◽  
Pooja Patel ◽  
Chinmayi Joshi ◽  
Brijesh Mishra ◽  
Shashikant Dubey ◽  
...  

AbstractEffect of nine different mono-frequency sound stimuli on two gram-negative bacteria (Pseudomonas aeruginosa and Serratia marcescens) was investigated. Frequency of the test sound ranged from 100 Hz to 2,000 Hz. Both the test bacteria responded differently to sonic stimulation. Sound corresponding to 600 HZ caused a notable reduction in quorum sensing (QS) regulated production of the pigment pyoverdine by P. aeruginosa. 400 Hz sound affected prodigiosin production by S. marcescens the most. 500 Hz sound could enhance prodigiosin production without affecting growth of the producing bacterium, suggesting the effect purely to be QS modulatory. This study has demonstrated the capacity of the sound waves of affecting bacterial growth and quorum sensing regulated metabolite production.

2020 ◽  
Vol 147 ◽  
pp. 03019
Author(s):  
Amara Faiz Wriahusna ◽  
Niswah Umhudloh Dzakiyya ◽  
Indun Dewi Puspita ◽  
Sri Pudjiraharti

Serratia marcescens PT6 is a Gram-negative bacteria isolated from shrimp pond sediment that capable of producing chitinase. This study aimed to observe the effect of agitation rate on growth and chitinase activity of S. marcescens PT-6 in a bioreactor. The production of chitinase was done in 1.5 l bioreactor using colloidal chitin broth at the condition of pH 7, the temperature of 30°C, aeration of 0.04 vvm, and variation of agitation rate (200, 350, 500 rpm). Bacterial growth was measured by colonies counting in agar medium, while chitinase activity was measured by means of colorimetric every day for four days incubation. The results of ANOVA analysis show that the agitation rate had no effect on bacterial growth, but a significant effect (P<0.05) was observed on chitinase activity. The highest growth and chitinase activity were obtained at 200 rpm, with the highest chitinase activity of 0.006 ± 0.001 U/ml was at day-2. This study implies that the optimized agitation rate in the bioreactor increased the chitinase activity produced by S. marcescens PT-6.


1998 ◽  
Vol 180 (9) ◽  
pp. 2402-2408 ◽  
Author(s):  
Kenji Nakahigashi ◽  
Hideki Yanagi ◽  
Takashi Yura

ABSTRACT The heat shock response in Escherichia coli is mediated primarily by the rpoH gene, encoding ς32, which is specifically required for transcription of heat shock genes. A number of ς32 homologs have recently been cloned from gram-negative bacteria that belong to the gamma or alpha subdivisions of the proteobacteria. We report here some of the regulatory features of several such homologs (RpoH) expressed in E. coli as well as in respective cognate bacteria. When expressed in an E. coli ΔrpoH strain lacking its own ς32, these homologs activated the transcription of heat shock genes (groE and dnaK) from the start sites normally used in E. coli. The level of RpoH inSerratia marcescens and Pseudomonas aeruginosacells was very low at 30°C but was elevated markedly upon a shift to 42°C, as found previously with E. coli. The increased RpoH levels upon heat shock resulted from both increased synthesis and stabilization of the normally unstable RpoH protein. In contrast, the RpoH level in Proteus mirabilis was relatively high at 30°C and increased less markedly upon heat shock, mostly by increased synthesis; this ς32 homolog was already stable at 30°C, and little further stabilization occurred upon the shift to 42°C. The increased synthesis of RpoH homologs in all these gamma proteobacteria was observed even in the presence of rifampin, suggesting that the induction occurred at the level of translation. Thus, the basic regulatory strategy of the heat shock response by enhancing the RpoH level is well conserved in the gamma proteobacteria, but some divergence in the actual mechanisms used occurred during evolution.


2015 ◽  
Vol 13 (3) ◽  
pp. 925-937 ◽  
Author(s):  
Nripendra Nath Biswas ◽  
Samuel K. Kutty ◽  
Nicolas Barraud ◽  
George M. Iskander ◽  
Renate Griffith ◽  
...  

Indole basedN-acylatedl-homoserine lactone (AHL) mimics were developed as quorum sensing (QS) inhibitors for Gram-negative bacteriaPseudomonas aeruginosaand can be used as novel antimicrobial agents.


RSC Advances ◽  
2021 ◽  
Vol 11 (46) ◽  
pp. 28797-28808
Author(s):  
Tung Truong Thanh ◽  
Huy Luong Xuan ◽  
Thang Nguyen Quoc

Benzo[d]thiazole-2-thiol bearing 2-oxo-2-substituted-phenylethan-1-yl as potent selective lasB quorum sensing inhibitors and anti-biofilm formation of Pseudomonas aeruginosa.


2021 ◽  
Vol 22 (10) ◽  
pp. 5328
Author(s):  
Miao Ma ◽  
Margaux Lustig ◽  
Michèle Salem ◽  
Dominique Mengin-Lecreulx ◽  
Gilles Phan ◽  
...  

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3745
Author(s):  
Dittu Suresh ◽  
Shekh Sabir ◽  
Tsz Tin Yu ◽  
Daniel Wenholz ◽  
Theerthankar Das ◽  
...  

Rottlerin is a natural product consisting of chalcone and flavonoid scaffolds, both of which have previously shown quorum sensing (QS) inhibition in various bacteria. Therefore, the unique rottlerin scaffold highlights great potential in inhibiting the QS system of Pseudomonas aeruginosa. Rottlerin analogues were synthesised by modifications at its chalcone- and methylene-bridged acetophenone moieties. The synthesis of analogues was achieved using an established five-step synthetic strategy for chalcone derivatives and utilising the Mannich reaction at C6 of the chromene to construct morpholine analogues. Several pyranochromene chalcone derivatives were also generated using aldol conditions. All the synthetic rottlerin derivatives were screened for QS inhibition and growth inhibition against the related LasR QS system. The pyranochromene chalcone structures displayed high QS inhibitory activity with the most potent compounds, 8b and 8d, achieving QS inhibition of 49.4% and 40.6% and no effect on bacterial growth inhibition at 31 µM, respectively. Both compounds also displayed moderate biofilm inhibitory activity and reduced the production of pyocyanin.


2021 ◽  
Vol 226 ◽  
pp. 113864
Author(s):  
Maxwell Ampomah-Wireko ◽  
Chunying Luo ◽  
Yaquan Cao ◽  
Huanhuan Wang ◽  
Lauraine Nininahazwe ◽  
...  

2012 ◽  
Vol 37 (2) ◽  
pp. 315-318 ◽  
Author(s):  
Chigusa Okano ◽  
Marina Arai ◽  
Eri Nasuno ◽  
Ken-ichi Iimura ◽  
Tomohiro Morohoshi ◽  
...  

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