@article { ISI:000329137400042, title = {Selective imaging of quorum sensing receptors in bacteria using fluorescent Au nanocluster probes surface functionalized with signal molecules}, journal = {ACS Applied Materials \& Interfaces}, volume = {5}, number = {24}, year = {2013}, month = {DEC}, pages = {13076-13081}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Fluorescent ultrasmall gold clusters decorated with bacterial quorum sensing signal molecules, acyl homoserine lactone, are synthesized. These fluorescent probes are found to have emission in the near-infrared spectral region advantageous for bioimaging. Imaging studies using different. strains of bacteria with and without acyl homoserine lactone receptors with the aid of confocal microscopy have shown that the probe interacts preferentially with cells possessing these receptors. This indicates that, with appropriate surface functionalization, the Au clusters can be used for receptor specific detection with enhanced selectivity.

}, keywords = {Au nanoclusters, Biosensor, fluorescence imaging, quorum sensing}, issn = {1944-8244}, doi = {10.1021/am404093m}, author = {Mukherji, Ruchira and Samanta, Anupam and Illathvalappil, Rajith and Chowdhury, Somak and Prabhune, Asmita and Devi, R. Nandini} } @article { ISI:000367612000010, title = {Penicillin acylases revisited: importance beyond their industrial utility}, journal = {Critical Reviews In Biotechnology}, volume = {36}, number = {2}, year = {2016}, month = {MAR}, pages = {303-316}, publisher = {TAYLOR \& FRANCIS LTD}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

It is of great importance to study the physiological roles of enzymes in nature; however, in some cases, it is not easily apparent. Penicillin acylases are pharmaceutically important enzymes that cleave the acyl side chains of penicillins, thus paving the way for production of newer semi-synthetic antibiotics. They are classified according to the type of penicillin (G or V) that they preferentially hydrolyze. Penicillin acylases are also used in the resolution of racemic mixtures and peptide synthesis. However, it is rather unfortunate that the focus on the use of penicillin acylases for industrial applications has stolen the spotlight from the study of the importance of these enzymes in natural metabolism. The penicillin acylases, so far characterized from different organisms, show differences in their structural nature and substrate spectrum. These enzymes are also closely related to the bacterial signalling phenomenon, quorum sensing, as detailed in this review. This review details studies on biochemical and structural characteristics of recently discovered penicillin acylases. We also attempt to organize the available insights into the possible in vivo role of penicillin acylases and related enzymes and emphasize the need to refocus research efforts in this direction.

}, keywords = {beta-lactam, choloyl glycine, in vivo role, Ntn hydrolases, pathogenicity, quorum sensing, regulation, signalling}, issn = {0738-8551}, doi = {10.3109/07388551.2014.960359}, author = {Avinash, Vellore Sunder and Pundle, Archana Vishnu and Ramasamy, Sureshkumar and Suresh, Cheravakkattu Gopalan} } @article {46672, title = {Inhibition of quorum sensing, motility and biofilm formation ofpseudomonas aeruginosaby copper oxide nanostructures}, journal = {Journal of Cluster Science}, volume = {32}, year = {2020}, month = {OCT}, pages = {1531 - 1541}, type = {Article; Early Access}, abstract = {

Quorum sensing (QS) is the communication between bacterial cells governed by their population density and regulated by the genes controlling virulence factors and biofilm formation. Multiple mechanisms of biofilms are resistive to antimicrobial chemotherapy; therefore novel strategies are required to overcome its limitations. Here, we report the effect of various copper oxide nanostructures (CuO-NSs) on quorum sensing inhibition. The two-dimensional CuO-NSs such as interlaced nanodiscs, nanodiscs and leaf-shaped nanosheets are prepared via a simple chemical method. The Quorum sensing inhibition (QSI) activity of all the CuO-NS are examined using reporter strainChromobacterium violaceumCV026 andEscherichia colipSB1142. We found that the CuO-interlaced nanodisc structures exhibit better QSI activity than nanodiscs and leaf-shaped sheets. The interlaced nanodisc structures are inhibited various long-chainN-acyl homoserine lactones (AHLs) mediated QS individually and confirmed by other QS-associated phenomena forPseudomonas aeruginosa, including biofilm inhibition, inhibition of virulence factors such as pyocyanin, protease production and swarming motility. Thus QSI activity of CuO-NSs is solely dependent on specific shape offering large surface area and more active sites. The CuO-NS is effective quorum sensing inhibitors, which has potential clinical applications in the management ofP. aeruginosaassociated infections.

}, keywords = {aeruginosa, Biofilm, Nanostructures, P, quorum sensing, Virulence factors}, isbn = {1572-8862}, issn = {1040-7278}, doi = {10.1007/s10876-020-01916-2}, author = {Desai, Dnyanada G. and Swarali, H. and Navale, Govinda R. and Prabhune, A. and Late, Dattatray J. and Dharne, Mahesh S. and Walke, Pravin S.} } @article {47498, title = {Red fluorescent ultra-small gold nanoclusters functionalized with signal molecules to probe specificity in quorum sensing receptors in gram-negative bacteria}, journal = {Archives of Microbiology}, year = {2021}, month = {JUN}, type = {Article; Early Access}, abstract = {Ultra-small (size < 2 nm) gold nanoclusters (AuNCs) are used as fluorescent probes which have excellent applications in bioimaging and sensing due to their emission in visible and NIR spectral region. Here, this property is exploited for understanding the quorum sensing phenomenon in bacteria which is regulated by signal molecules which are specific to various species. AuNCs are then functionalized with the signal molecules, Acyl Homoserine Lactones (AHL) of varying carbon chain length, C-6, C-8, and C-12 without 3rd C modification, to sense different strains of gram-negative bacteria i.e., Escherichia coli, Cronobacter sakazakii and Pseudomonas aeruginosa. In the concentration employed, selectivity to a limited extent is observed between the three Gram-negative bacteria tested. E. coli showed emission with all the AHL conjugates and P. aeruginosa did not interact with any of the three conjugates, whereas C. sakazakii showed specificity to C-8AHL. This is probably due to selectivity for cognate AHL molecules of appropriate concentrations.}, keywords = {acyl homoserine lactone, fluorescence imaging, Gold nanoclusters, quorum sensing, Receptors, selectivity}, issn = {0302-8933}, doi = {10.1007/s00203-021-02338-y, Early Access Date = JUN 2021}, author = {Chahande, Anurag M. and Lathigara, Disha and Prabhune, Asmita A. and Devi, R. Nandini} }