Combined antibacterial and antibiofilm activity of phenyllactic acid and bacteriocin XSJ01 against Shigella flexneri

Background and Objectives: The aim of this study was to evaluate the antibacterial and antibiofilm activity of recombinant Azurin from Pseudomonas aeruginosa against different bacterial species. Materials and Methods: The azurin gene was cloned in the pET21a vector. The pET21a-azurin construct was transformed into Escherichia coli BL21. The recombinant Azurin was expressed and purified using affinity chromatography and con- firmed by Western blotting. The cytotoxicity of rAzurin was assessed on peripheral blood mononuclear cells. Antibacterial and antibiofilm activity of rAzurin with different concentrations were determined by micro-broth dilution and crystal violet methods, respectively. The effect of rAzurin on bacterial species was statistically analyzed by t- test and spearman correla- tion. Results: The identity of purified protein was confirmed by blotting and distinguished as a 14 kDa band on 15% SDS-PAGE. The IC50 of rAzurin on Peripheral Blood Mononuclear Cell (PBMC) was determined as 377.91±0.5 µg/mL in 24 h. Vibrio cholerae and Campilobacter jejuni displayed the most sensitivity to rAzurin (27.5 and 55 μg/mL, respectively) and the highest resistance (220 μg/mL) was displayed by P. aeruginosa and E. coli. The MIC for other species was 110 μg/mL. The Minimum Biofilm Inhibition Concentration (MBIC) was determined as 220 μg/mL for Salmonella enterica and V. cholerae, 300 μg/mL for Shigella sonnei, Shigella flexneri and P. aeruginosa and 440 μg/mL for the other species. The antimicrobial effect of rAzurin on bacterial species were significant (p value<0.05) and correlation coefficient was negative. Conclusion: The rAzurin appears to be an appropriate choice and a new strategy for prevention of bacterial infection. It inhibits bacterial growth and biofilm formation and candidates as antimicrobial peptides.

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Antibacterial and antibiofilm activity of phenyllactic acid against Enterobacter cloacae

Food Control ◽

10.1016/j.foodcont.2017.09.004 ◽

2018 ◽

Vol 84 ◽

pp. 442-448 ◽

Cited By ~ 36

Author(s):

Fang Liu ◽

Fengting Wang ◽

Lihui Du ◽

Tong Zhao ◽

Michael P. Doyle ◽

...

Keyword(s):

Enterobacter Cloacae ◽

Antibiofilm Activity ◽

Phenyllactic Acid

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Antibiofilm Activity of Lactobacillus plantarum 12 Exopolysaccharides against Shigella flexneri

Applied and Environmental Microbiology ◽

10.1128/aem.00694-20 ◽

2020 ◽

Vol 86 (15) ◽

Cited By ~ 1

Author(s):

Yinglong Song ◽

Mengying Sun ◽

Lu Feng ◽

Xue Liang ◽

Xing Song ◽

...

Keyword(s):

Developing Countries ◽

Lactobacillus Plantarum ◽

Biofilm Formation ◽

Glucuronic Acid ◽

Shigella Flexneri ◽

Molar Ratio ◽

Composition Analysis ◽

Antibiofilm Activity ◽

Content Type ◽

Ht 29

ABSTRACT In developing countries, Shigella flexneri is the most common enteric pathogen causing bacillary dysentery. Biofilm formation by S. flexneri can cause the emergence of antibiotic-resistant strains, which poses serious threats to food safety and human health. In this study, the effects of Lactobacillus plantarum 12 exopolysaccharides (L-EPSs) and S. flexneri exopolysaccharides (S-EPSs) on S. flexneri CMCC51574 biofilm formation were investigated. The results showed that L-EPS could decrease polysaccharide production in the extracellular polymeric matrix of S. flexneri and inhibit biofilm formation by S. flexneri. L-EPS could decrease the minimum biofilm elimination concentration (MBEC) of antibiotics against S. flexneri biofilm and inhibit S. flexneri adhesion to and invasion into HT-29 cell monolayers, which might be ascribed to S. flexneri biofilm disturbance by L-EPS. In contrast, S-EPS exhibited the opposite effects compared to L-EPS. The monosaccharide composition analysis showed that L-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, galactose, and xylose, with the molar ratio of 32.26:0.99:1.79:5.63:0.05:4.07, while S-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, and galactose, with the molar ratio of 25.43:2.28:7.13:5.35. L-EPS was separated into the neutral polysaccharide L-EPS 1-1 and the acidic polysaccharide L-EPS 2-1 by ion-exchange chromatography and gel chromatography. L-EPS 2-1 exerted higher antibiofilm activity than L-EPS 1-1. The antibiofilm activity of L-EPS might be associated with its structure. IMPORTANCE S. flexneri is a widespread foodborne pathogen causing food contamination and responsible for food poisoning outbreaks related to various foods in developing countries. Not only has biofilm formation by S. flexneri been difficult to eliminate, but it has also increased the drug resistance of the strain. In the present study, it was demonstrated that L-EPSs secreted by Lactobacillus plantrum 12 could inhibit S. flexneri biofilm formation on, adhesion to, and invasion into HT-29 cells. Also, L-EPSs could decrease the minimum biofilm elimination concentration (MBEC) of the antibiotics used against S. flexneri biofilm. Therefore, L-EPSs were shown to be bioactive macromolecules with the potential ability to act against S. flexneri infections.

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Ultrastructure of periplasmic bodies in gram-negative bacteria

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100160753 ◽

1990 ◽

Vol 48 (3) ◽

pp. 640-641

Author(s):

Xie Nianming ◽

Ding Shaoqing ◽

Wang Luping ◽

Yuan Zenglin ◽

Zhan Guolai ◽

...

Keyword(s):

Electron Microscope ◽

Campylobacter Jejuni ◽

Proteus Mirabilis ◽

Shigella Flexneri ◽

Morphological Description ◽

Gram Negative Bacteria ◽

Periplasmic Space ◽

Clostridium Tetani ◽

Gram Negative ◽

Brucella Canis

Perhaps the data about periplasmic enzymes are obtained through biochemical methods but lack of morphological description. We have proved the existence of periplasmic bodies by electron microscope and described their ultrastructures. We hope this report may draw the attention of biochemists and mrophologists to collaborate on researches in periplasmic enzymes or periplasmic bodies with each other.One or more independent bodies may be seen in the periplasmic space between outer and inner membranes of Gram-negative bacteria, which we called periplasmic bodies. The periplasmic bodies have been found in seven species of bacteria at least, including the Pseudomonas aeroginosa. Shigella flexneri, Echerichia coli. Yersinia pestis, Campylobacter jejuni, Proteus mirabilis, Clostridium tetani. Vibrio cholerae and Brucella canis.

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