Effect of Thiophenone Compound on Motility and Caseinase Production of Aeromonas hydrophila

Motility and caseinase production are part of bacterial virulence factors which are regulated by a bacterial intercellular communication system, often called quorum sensing (QS). This study aims to determine the effect of the QS inhibitor compound thiophenone in reducing those virulence factors. This research was conducted at the Laboratory of Fisheries Science, Faculty of Marine Science and Fisheries, Udayana University, from December 2019 to March 2020. This study tested 3 different treatments with 3 repetitions for each treatment. Treatment A as control (without the addition of thiophenone), treatment B (addition of 5 ?M thiophenone), and C treatment (addition of 10 ?M thiophenone). The results showed that thiophenone compounds can inhibit the QS system of Aeromonas hydrophila. It can be seen from the significantly reduced (P<0.05) motility and caseinase enzyme activity of A. hydrophila compared to without addition of thiophenone compounds. The average diameter of the caseinase enzyme production produced in treatment A at 22 hours was 21.40±0.36 mm, in treatment B was 19.70±0.2 mm and in treatment, C was 17.87±0.05 mm. Whereas in motility, the resulting average diameter in treatment A at 22 hours was 6.57±0.61 mm, in treatment B was 5.67±0.35 mm and in treatment, C was 5.10±0.6 mm. These results indicate that the QS thiophenone inhibitor compound can reduce virulence factors, namely motility and caseinase production from pathogenic bacteria A. hydrophila. Treatment C can decrease virulence factors compared to treatment A and B.

Download Full-text

New generation of peptide antibiotics.

Acta Biochimica Polonica ◽

10.18388/abp.2005_3423 ◽

2005 ◽

Vol 52 (3) ◽

pp. 633-638 ◽

Cited By ~ 12

Author(s):

Adam Dubin ◽

Paweł Mak ◽

Grzegorz Dubin ◽

Małgorzata Rzychon ◽

Justyna Stec-Niemczyk ◽

...

Keyword(s):

Virulence Factors ◽

Broad Spectrum ◽

Pathogenic Bacteria ◽

Bacterial Virulence ◽

Antibacterial Peptides ◽

Peptide Antibiotics ◽

Fields Of Study ◽

Secreted Proteases ◽

New Generation ◽

Further Development

The increasing antibiotic resistance of pathogenic bacteria calls for the development of alternative antimicrobial strategies. Possible approaches include the development of novel, broad-spectrum antibiotics as well as specific targeting of individual bacterial virulence factors. It is impossible to decide currently which strategy will prove more successful in the future since they both promise different advantages, but also introduce diverse problems. Considering both approaches, our laboratory's research focuses on the evaluation of hemocidins, broad-spectrum antibacterial peptides derived from hemoglobin and myoglobin, and staphostatins, specific inhibitors of staphopains -- Staphylococcus aureus secreted proteases that are virulence factors regarded as possible targets for therapy. The article summarizes recent advances in both fields of study and presents perspectives for further development and possible applications.

Download Full-text

A Structural Approach to Anti-Virulence: A Discovery Pipeline

Microorganisms ◽

10.3390/microorganisms9122514 ◽

2021 ◽

Vol 9 (12) ◽

pp. 2514

Author(s):

Michael McCarthy ◽

Monica Goncalves ◽

Hannah Powell ◽

Blake Morey ◽

Madison Turner ◽

...

Keyword(s):

Host Cell ◽

Virulence Factors ◽

Pathogenic Bacteria ◽

Bacterial Virulence ◽

Structural Approach ◽

Multi Drug Resistance ◽

Enzyme Active Site ◽

Catalytic Function ◽

Molecule Inhibitor ◽

High Resolution Structure

The anti-virulence strategy is designed to prevent bacterial virulence factors produced by pathogenic bacteria from initiating and sustaining an infection. One family of bacterial virulence factors is the mono-ADP-ribosyltransferase toxins, which are produced by pathogens as tools to compromise the target host cell. These toxins are bacterial enzymes that exploit host cellular NAD+ as the donor substrate to modify an essential macromolecule acceptor target in the host cell. This biochemical reaction modifies the target macromolecule (often protein or DNA) and functions in a binary fashion to turn the target activity on or off by blocking or impairing a critical process or pathway in the host. A structural biology approach to the anti-virulence method to neutralize the cytotoxic effect of these factors requires the search and design of small molecules that bind tightly to the enzyme active site and prevent catalytic function essentially disarming the pathogen. This method requires a high-resolution structure to serve as the model for small molecule inhibitor development, which illuminates the path to drug development. This alternative strategy to antibiotic therapy represents a paradigm shift that may circumvent multi-drug resistance in the offending microbe through anti-virulence therapy. In this report, the rationale for the anti-virulence structural approach will be discussed along with recent efforts to apply this method to treat honey bee diseases using natural products.

Download Full-text

Prodigiosin inhibits bacterial growth and virulence factors as a potential physiological response to interspecies competition

PLoS ONE ◽

10.1371/journal.pone.0253445 ◽

2021 ◽

Vol 16 (6) ◽

pp. e0253445

Author(s):

Chee-Hoo Yip ◽

Sobina Mahalingam ◽

Kiew-Lian Wan ◽

Sheila Nathan

Keyword(s):

Staphylococcus Aureus ◽

Liquid Chromatography ◽

Virulence Factors ◽

Bacterial Growth ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Bacterial Virulence ◽

Protease Production ◽

Natural Soil ◽

Microbial Competition

Prodigiosin, a red linear tripyrrole pigment, has long been recognised for its antimicrobial property. However, the physiological contribution of prodigiosin to the survival of its producing hosts still remains undefined. Hence, the aim of this study was to investigate the biological role of prodigiosin from Serratia marcescens, particularly in microbial competition through its antimicrobial activity, towards the growth and secreted virulence factors of four clinical pathogenic bacteria (methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Salmonella enterica serovar Typhimurium and Pseudomonas aeruginosa) as well as Staphylococcus aureus and Escherichia coli. Prodigiosin was first extracted from S. marcescens and its purity confirmed by absorption spectrum, high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrophotometry (LC-MS/MS). The extracted prodigiosin was antagonistic towards all the tested bacteria. A disc-diffusion assay showed that prodigiosin is more selective towards Gram-positive bacteria and inhibited the growth of MRSA, S. aureus and E. faecalis and Gram-negative E. coli. A minimum inhibitory concentration of 10 μg/μL of prodigiosin was required to inhibit the growth of S. aureus, E. coli and E. faecalis whereas > 10 μg/μL was required to inhibit MRSA growth. We further assessed the effect of prodigiosin towards bacterial virulence factors such as haemolysin and production of protease as well as on biofilm formation. Prodigiosin did not inhibit haemolysis activity of clinically associated bacteria but was able to reduce protease activity for MRSA, E. coli and E. faecalis as well as decrease E. faecalis, Salmonella Typhimurium and E. coli biofilm formation. Results of this study show that in addition to its role in inhibiting bacterial growth, prodigiosin also inhibits the bacterial virulence factor protease production and biofilm formation, two strategies employed by bacteria in response to microbial competition. As clinical pathogens were more resistant to prodigiosin, we propose that prodigiosin is physiologically important for S. marcescens to compete against other bacteria in its natural soil and surface water environments.

Download Full-text

mRNA Regulatory elements and bacterial virulence.

Acta Biochimica Polonica ◽

10.18388/abp.2014_1924 ◽

2014 ◽

Vol 61 (1) ◽

Author(s):

Małgorzata Pawlikowska-Warych ◽

Wiesław Deptuła

Keyword(s):

Virulence Factors ◽

Pathogenic Bacteria ◽

Regulatory Elements ◽

Bacterial Virulence ◽

Non Coding Rna

Pathogenic bacteria cause many diseases, some of which are fatal. For researchers, it is a challenge to understand bacterial mechanisms of pathogenicity, including their virulence pathways regulated by RNA. This work presents data on the mechanisms of regulation and expression of several virulence factors coded by RNA, namely 5' UTR fragments, riboswitches and small non-coding RNA (sRNA).

Download Full-text

Faculty Opinions recommendation of Long-distance delivery of bacterial virulence factors by Pseudomonas aeruginosa outer membrane vesicles.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1160071.623233 ◽

2009 ◽

Author(s):

Fergal O'Gara

Keyword(s):

Pseudomonas Aeruginosa ◽

Outer Membrane ◽

Virulence Factors ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Bacterial Virulence ◽

Long Distance ◽

Distance Delivery

Download Full-text

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.

Download Full-text

Interference of quorum sensing regulated bacterial virulence factors and biofilms by Plumbago zeylanica extract

Microscopy Research and Technique ◽

10.1002/jemt.23872 ◽

2021 ◽

Author(s):

Faizan Abul Qais ◽

Iqbal Ahmad ◽

Fohad Mabood Husain ◽

Suliman Y. Alomar ◽

Naushad Ahmad ◽

...

Keyword(s):

Quorum Sensing ◽

Virulence Factors ◽

Bacterial Virulence ◽

Plumbago Zeylanica

Download Full-text

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.

Download Full-text