Screening antibiofilm and quorum-quenching activity of Actinomycetes isolates against aquatic pathogens

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

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Anti-quorum quenching activity of methyl gallate isolated from galls of Guiera senegalensis J. F. Gmel (Combretaceae)

African Journal of Microbiology Research ◽

10.5897/ajmr2019.9056 ◽

2019 ◽

Vol 13 (16) ◽

pp. 290-297 ◽

Cited By ~ 1

Author(s):

Ouedraogo Vincent ◽

Alexandre Eric Djifaby Sombié Pierre ◽

Compaoré Moussa ◽

Kiendrébéogo Martin

Keyword(s):

Quorum Quenching ◽

Methyl Gallate ◽

Guiera Senegalensis

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Extract from phyllosphere bacteria with antibiofilm and quorum quenching activity to control several fish pathogenic bacteria

BMC Research Notes ◽

10.1186/s13104-021-05612-w ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Olivia Nathalia ◽

Diana Elizabeth Waturangi

Keyword(s):

Streptococcus Agalactiae ◽

Aeromonas Hydrophila ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Vibrio Harveyi ◽

Quorum Quenching ◽

Indicator Bacteria ◽

Antibiofilm Activity ◽

Fish Pathogen ◽

Phyllosphere Bacteria

Abstract Objective The objective of this research were to screen quorum quenching activity compound from phyllosphere bacteria as well as antibiofilm activity against several fish pathogen bacteria such as Aeromonas hydrophila, Streptococcus agalactiae, and Vibrio harveyi. Results We found eight phyllosphere bacteria isolates with potential quorum quenching activity to inhibit Chromobacterium violaceum as indicator bacteria. Crude extracts (20 mg/mL) showed various antibiofilm activity against fish pathogenic bacteria used in this study. Isolate JB 17B showed the highest activity to inhibit biofilm formation of A. hydrophila and V. harveyi, meanwhile isolate JB 3B showed the highest activity to inhibit biofilm of S. agalactiae. From destruction assay, isolate JB 8F showed the highest activity to disrupt biofilm of A. hydrophila isolate JB 20B showed the highest activity to disrupt biofilm of V. harveyi, isolate JB 17B also showed the highest activity to disrupt biofilm of S. agalactiae.

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Molecular docking, quorum quenching effect, antibiofilm activity and safety profile of silver-complexed sulfonamide on Pseudomonas aeruginosa

Biofouling ◽

10.1080/08927014.2021.1939019 ◽

2021 ◽

pp. 1-17

Author(s):

Fallon dos Santos Siqueira ◽

Camilla Filippi dos Santos Alves ◽

Alencar Kolinski Machado ◽

Josiéli Demétrio Siqueira ◽

Thiago dos Santos ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Molecular Docking ◽

Safety Profile ◽

Quorum Quenching ◽

Antibiofilm Activity ◽

Quenching Effect

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A single point mutation converts a glutaryl-7-aminocephalosporanic acid acylase into an N-acyl-homoserine lactone acylase

Biotechnology Letters ◽

10.1007/s10529-021-03135-9 ◽

2021 ◽

Author(s):

Shereen A. Murugayah ◽

Gary B. Evans ◽

Joel D. A. Tyndall ◽

Monica L. Gerth

Keyword(s):

Single Point ◽

Quorum Quenching ◽

Homoserine Lactone ◽

Site Directed Mutagenesis ◽

Saturation Mutagenesis ◽

Single Amino Acid ◽

Single Point Mutation ◽

Acyl Homoserine Lactone ◽

Signalling Molecules ◽

Single Amino Acid Residue

Abstract Objective To change the specificity of a glutaryl-7-aminocephalosporanic acid acylase (GCA) towards N-acyl homoserine lactones (AHLs; quorum sensing signalling molecules) by site-directed mutagenesis. Results Seven residues were identified by analysis of existing crystal structures as potential determinants of substrate specificity. Site-saturation mutagenesis libraries were created for each of the seven selected positions. High-throughput activity screening of each library identified two variants—Arg255Ala, Arg255Gly—with new activities towards N-acyl homoserine lactone substrates. Structural modelling of the Arg255Gly mutation suggests that the smaller side-chain of glycine (as compared to arginine in the wild-type enzyme) avoids a key clash with the acyl group of the N-acyl homoserine lactone substrate. Conclusions Mutation of a single amino acid residue successfully converted a GCA (with no detectable activity against AHLs) into an AHL acylase. This approach may be useful for further engineering of ‘quorum quenching’ enzymes.

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Quorum-quenching activity of some Iranian medicinal plants

New Microbes and New Infections ◽

10.1016/j.nmni.2021.100882 ◽

2021 ◽

pp. 100882

Author(s):

Farhad Moradi ◽

Nahal Hadi

Keyword(s):

Medicinal Plants ◽

Quorum Quenching

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Attenuation of Aeromonas hydrophila Infection in Carassius auratus by YtnP, a N-acyl Homoserine Lactonase from Bacillus licheniformis T-1

Antibiotics ◽

10.3390/antibiotics10060631 ◽

2021 ◽

Vol 10 (6) ◽

pp. 631

Author(s):

Mengfan Peng ◽

Wentao Tong ◽

Zhen Zhao ◽

Ling Xiao ◽

Zhaoyue Wang ◽

...

Keyword(s):

Virulence Factors ◽

Bacillus Licheniformis ◽

Aeromonas Hydrophila ◽

Biofilm Formation ◽

Carassius Auratus ◽

Quorum Quenching ◽

Inhibition Rate ◽

Sequence Identity

In this experiment, the quorum quenching gene ytnP of Bacillus licheniformis T-1 was cloned and expressed, and the effect against infection of Aeromonas hydrophila ATCC 7966 was evaluated in vitro and vivo. The BLAST results revealed a 99% sequence identity between the ytnP gene of T-1 and its homolog in B.subtilis sub sp. BSP1, and the dendroGram showed that the similarity in the YtnP protein in T-1 was 100% in comparison with B.subtilis 3610, which was categorized as the Aidc cluster of the MBL family. The AHL lactonase activity of the purified YtnP was detected as 1.097 ± 0.7 U/mL with C6-HSL as the substrate. Otherwise, purified YtnP protein could significantly inhibit the biofilm formation of A.hydrophila ATCC 7966 with an inhibition rate of 68%. The MIC of thiamphenicol and doxycycline hydrochloride against A. hydrophila reduced from 4 μg/mL and 0.5 μg/mL to 1 μg/mL and 0.125 μg/mL, respectively, in the presence of YtnP. In addition, YtnP significantly inhibited the expression of five virulence factors hem, ahyB, ast, ep, aerA of A. hydrophila ATCC 7966 as well (p < 0.05). The results of inhibition on virulence showed a time-dependence tendency, while the strongest anti-virulence effects were within 4–24 h. In vivo, when the YtnP protein was co-injected intraperitoneally with A. hydrophila ATCC 7966, it attenuated the pathogenicity of A. hydrophila and the accumulated mortality was 27 ± 4.14% at 96 h, which was significantly lower than the average mortality of 78 ± 2.57% of the Carassius auratus injected with 108 CFU/mL of A. hydrophila ATCC 7966 only (p < 0.001). In conclusion, the AHL lactonase in B. licheniformis T-1 was proven to be YtnP protein and could be developed into an agent against infection of A. hydrophila in aquaculture.

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