Antibacterial and Antibiofilm Activities of Chloroindoles Against Vibrio parahaemolyticus

Vibrio parahaemolyticus is a food-borne pathogen recognized as the prominent cause of seafood-borne gastroenteritis globally, necessitating novel therapeutic strategies. This study examined the antimicrobial and antivirulence properties of indole and 16 halogenated indoles on V. parahaemolyticus. Among them, 4-chloroindole, 7-chloroindole, 4-iodoindole, and 7-iodoindole effectively inhibited planktonic cell growth, biofilm formation, bacterial motility, fimbrial activity, hydrophobicity, protease activity, and indole production. Specifically, 4-chloroindole at 20 μg/mL inhibited more than 80% of biofilm formation with a minimum inhibitory concentration (MIC) of 50 μg/mL against V. parahaemolyticus and Vibrio harveyi. In contrast, 7-chloroindole inhibited biofilm formation without affecting planktonic cell growth with a MIC of 200 μg/mL. Both chlorinated indoles caused visible damage to the cell membrane, and 4-chloroindole at 100 μg/mL had a bactericidal effect on V. parahaemolyticus within 30 min treatment, which is superior to the effect of tetracycline at the same dose. The quantitative structure-activity relationship (QSAR) analyses revealed that chloro and bromo at positions 4 or 5 of the indole are essential for eradicating the growth of V. parahaemolyticus. These results suggest that halogenated indoles have potential use in antimicrobial and antivirulence strategies against Vibrio species.

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Exogenous fungal quorum sensing molecules inhibit planktonic cell growth and modulate filamentation and biofilm formation in the Sporothrix schenckii complex

Biofouling ◽

10.1080/08927014.2020.1828373 ◽

2020 ◽

Vol 36 (8) ◽

pp. 909-921

Author(s):

Raimunda Sâmia Nogueira Brilhante ◽

Vandbergue Santos Pereira ◽

Augusto Feynman Dias Nobre ◽

Jonathas Sales de Oliveira ◽

Mirele Rodrigues Fernandes ◽

...

Keyword(s):

Cell Growth ◽

Quorum Sensing ◽

Biofilm Formation ◽

Sporothrix Schenckii ◽

Planktonic Cell

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Identification of LuxR Family Regulators That Integrate Into Quorum Sensing Circuit in Vibrio parahaemolyticus

Frontiers in Microbiology ◽

10.3389/fmicb.2021.691842 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xiaojun Zhong ◽

Ranran Lu ◽

Fuwen Liu ◽

Jinjie Ye ◽

Junyang Zhao ◽

...

Keyword(s):

Quorum Sensing ◽

Biofilm Formation ◽

Vibrio Parahaemolyticus ◽

Wide Spectrum ◽

Cell Communication ◽

Systematic Research ◽

Global Regulator ◽

Food Borne ◽

Reporter Assays ◽

Complex Regulatory Network

Vibrio parahaemolyticus is one of the most important food-borne pathogens that cause economic and public health problems worldwide. Quorum sensing (QS) is a way for the cell-cell communication between bacteria that controls a wide spectrum of processes and phenotypic behaviors. In this study, we performed a systematic research of LuxR family regulators in V. parahaemolyticus and found that they influence the bacterial growth and biofilm formation. We then established a QS reporter plasmid based on bioluminescence luxCDABE operon of Vibrio harveyi and demonstrated that several LuxR family regulators integrated into QS circuit in V. parahaemolyticus. Thereinto, a novel LuxR family regulator, named RobA, was identified as a global regulator by RNA-sequencing analyses, which affected the transcription of 515 genes in V. parahaemolyticus. Subsequent studies confirmed that RobA regulated the expression of the exopolysaccharides (EPS) synthesis cluster and thus controlled the biofilm formation. In addition, bioluminescence reporter assays showed that RobA plays a key role in the QS circuit by regulating the expression of opaR, aphA, cpsQ-mfpABC, cpsS, and scrO. We further demonstrated that the regulation of RobA to EPS and MfpABC depended on OpaR and CpsQ, which combined the QS signal with bis-(3′-5′)-cyclic dimeric GMP to construct a complex regulatory network of biofilm formation. Our data provided new insights into the bacterial QS mechanisms and biofilm formation in V. parahaemolyticus.

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Bacteriostatic effects of benzyl isothiocyanate on Vibrio parahaemolyticus: Transcriptomic analysis and morphological verification

10.21203/rs.3.rs-258843/v1 ◽

2021 ◽

Author(s):

Ke Zhang ◽

Jie Song ◽

Hongyan Wu ◽

Hongshun Hao ◽

Jingran Bi ◽

...

Keyword(s):

Biofilm Formation ◽

Vibrio Parahaemolyticus ◽

Virulence Gene ◽

Antibacterial Activities ◽

Transcriptomic Analysis ◽

Control Group ◽

Benzyl Isothiocyanate ◽

Virulence Gene Expression ◽

Food Borne ◽

Upregulated Genes

Abstract Vibrio parahaemolyticus is a food-borne pathogenic microorganism that commonly exists in aquatic products. In this study, the antibacterial activities of benzyl isothiocyanate (BITC) against V. parahaemolyticus were investigated by both transcriptomic analysis and morphological verification. Treatment with 1/8 minimum inhibitory concentration (1/8 MIC) BITC resulted in 234 upregulated genes and 273 downregulated genes. We selected six virulence genes that were significantly downregulated and verified them using quantitative real-time reverse transcription-polymerase chain reaction. The verification results revealed that the relative expression levels of the six genes VP0820, VP0548, VP2233, VPA2362, fliA and fliG were only 31.0%, 31.1%, 55.8%, 57.0%, 75.3%, and 79.9% of the control group, respectively. Among them, genes VP2233, fliA and fliG are related to flagella and VP2362 can regulate a protein relevant to biofilm formation. Morphologically, we verified that the swimming diffusion diameter of V. parahaemolyticus was significantly reduced by 14.9%, and biofilm formation was significantly inhibited by treatment with 1/8 MIC BITC. These results indicated that 1/8 MIC BITC had antibacterial effect on V. parahaemolyticus by inhibiting virulence gene expression related to flagella and biofilm. These findings are helpful to further elucidate the bacteriostatic mechanism of BITC on V. parahaemolyticus and other food-borne pathogens.

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Effects of Nicotine on Streptococcus gordonii Growth, Biofilm Formation, and Cell Aggregation

Applied and Environmental Microbiology ◽

10.1128/aem.02395-14 ◽

2014 ◽

Vol 80 (23) ◽

pp. 7212-7218 ◽

Cited By ~ 34

Author(s):

R. Huang ◽

M. Li ◽

M. Ye ◽

K. Yang ◽

X. Xu ◽

...

Keyword(s):

Gene Expression ◽

Cell Growth ◽

Periodontal Disease ◽

Biofilm Formation ◽

Binding Proteins ◽

Cell Aggregation ◽

Planktonic Cell ◽

Laser Scanning Microscopy ◽

Streptococcus Gordonii ◽

Content Type

ABSTRACTStreptococcus gordoniiis a commensal species of human oral flora. It initiates dental biofilm formation and provides binding sites for later colonizers to attach to and generate mature biofilm. Smoking is the second highest risk factor for periodontal disease, and cigarette smoke extract has been reported to facilitatePorphyromonas gingivalis-S. gordoniidual-species biofilm formation. Our hypothesis is that nicotine, one of the most important and active components of tobacco, stimulatesS. gordoniimultiplication and aggregation. In the present study,S. gordoniiplanktonic cell growth (kinetic absorbance and CFU), biofilm formation (crystal violet stain and confocal laser scanning microscopy [CLSM]), aggregation with/without sucrose, and 11 genes that encode binding proteins or regulators of gene expression were investigated. Results demonstrated planktonic cell growth was stimulated by 1 to 4 mg/ml nicotine treatment. Biofilm formation was increased at 0.5 to 4 mg/ml nicotine. CLSM indicated bacterial cell mass was increased by 2 and 4 mg/ml nicotine, but biofilm extracellular polysaccharide was not significantly affected by nicotine. Cell aggregation was upregulated by 4, 8, and 16 mg/ml nicotine with sucrose and by 16 mg/ml nicotine without sucrose. Quantitative reverse transcriptase PCR indicatedS. gordoniiabpA,scaA,ccpA, andsrtAwere upregulated in planktonic cells by 2 mg/ml nicotine. In conclusion, nicotine stimulatesS. gordoniiplanktonic cell growth, biofilm formation, aggregation, and gene expression of binding proteins. Those effects may promote later pathogen attachment to tooth surfaces, the accumulation of tooth calculus, and the development of periodontal disease in cigarette smokers.

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Inhibition of Bacterial Biofilm Formation by Phytotherapeutics with Focus on Overcoming Antimicrobial Resistance

Current Pharmaceutical Design ◽

10.2174/1381612826666200212121710 ◽

2020 ◽

Vol 26 (24) ◽

pp. 2807-2816 ◽

Cited By ~ 1

Author(s):

Yun Su Jang ◽

Tímea Mosolygó

Keyword(s):

Antimicrobial Resistance ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Bacterial Biofilm ◽

Experimental Investigations ◽

Resistant Bacteria ◽

Salmonella Spp ◽

Food Borne ◽

High Prevalence ◽

Scientific Attention

: Bacteria within biofilms are more resistant to antibiotics and chemical agents than planktonic bacteria in suspension. Treatment of biofilm-associated infections inevitably involves high dosages and prolonged courses of antimicrobial agents; therefore, there is a potential risk of the development of antimicrobial resistance (AMR). Due to the high prevalence of AMR and its association with biofilm formation, investigation of more effective anti-biofilm agents is required. : From ancient times, herbs and spices have been used to preserve foods, and their antimicrobial, anti-biofilm and anti-quorum sensing properties are well known. Moreover, phytochemicals exert their anti-biofilm properties at sub-inhibitory concentrations without providing the opportunity for the emergence of resistant bacteria or harming the host microbiota. : With increasing scientific attention to natural phytotherapeutic agents, numerous experimental investigations have been conducted in recent years. The present paper aims to review the articles published in the last decade in order to summarize a) our current understanding of AMR in correlation with biofilm formation and b) the evidence of phytotherapeutic agents against bacterial biofilms and their mechanisms of action. The main focus has been put on herbal anti-biofilm compounds tested to date in association with Staphylococcus aureus, Pseudomonas aeruginosa and food-borne pathogens (Salmonella spp., Campylobacter spp., Listeria monocytogenes and Escherichia coli).

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Biofilm Formation and Associated Genes in Listeria Monocytogenes

THE INDIAN JOURNAL OF VETERINARY SCIENCES AND BIOTECHNOLOGY ◽

10.21887/ijvsbt.v12i3.7079 ◽

2017 ◽

Vol 12 (3) ◽

Author(s):

S. R. Warke ◽

V. C. Ingle ◽

N. V. Kurkure ◽

P. A. Tembhurne ◽

Minakshi Prasad ◽

...

Keyword(s):

Public Health ◽

Listeria Monocytogenes ◽

Multiplex Pcr ◽

Food Processing ◽

Biofilm Formation ◽

Milk Samples ◽

Biofilm Production ◽

Food Borne ◽

Serious Infections ◽

Microtiter Assay

Listeria monocytogenes, an opportunistic food borne pathogen can cause serious infections in immunocompromised individuals. L. monocytogenes is capable of producing biofilm on the surface of food processing lines and instruments.The biofilm transfers contamination to food products and impose risk to public health. In the present study biofilm producing ability of L. monocytogenes isolates were investigated phenotypically and genotypically by microtiter assay and multiplex PCR, respectively. Out of 38 L. monocytogenes isolates 14 were recovered from animal clinical cases, 12 bovine environment and 12 from milk samples. A total of 3 (21.42%) clinical, 2 (16.66%) environment and 3 (25%) milk samples respectively, revealed biofilm production in microtiter assay. Cumulative results showed that 23 (60.52%) out of 38 strains of L. monocytogenes were positive for luxS and flaA gene and 1 (2.63%) was positive only for the flaA gene.

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Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources

Pharmaceuticals ◽

10.3390/ph14050414 ◽

2021 ◽

Vol 14 (5) ◽

pp. 414

Author(s):

Neda Aničić ◽

Uroš Gašić ◽

Feng Lu ◽

Ana Ćirić ◽

Marija Ivanov ◽

...

Keyword(s):

Biofilm Formation ◽

Food Industry ◽

Balkan Peninsula ◽

Antimicrobial Activities ◽

Natural Sources ◽

E Coli ◽

Food Borne ◽

Metabolite Profiles ◽

Aspergillus Sp ◽

First Time

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

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Superhydrophobic Nanocoatings as Intervention against Biofilm-Associated Bacterial Infections

Nanomaterials ◽

10.3390/nano11041046 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1046

Author(s):

Yinghan Chan ◽

Xun Hui Wu ◽

Buong Woei Chieng ◽

Nor Azowa Ibrahim ◽

Yoon Yee Then

Keyword(s):

Biofilm Formation ◽

Bacterial Infections ◽

Therapeutic Strategies ◽

Public Healthcare ◽

Persistent Infections ◽

Promising Strategy ◽

Antimicrobial Interventions ◽

Novel Therapeutic Strategies ◽

Insight Into ◽

Microbial Attachment

Biofilm formation represents a significant cause of concern as it has been associated with increased morbidity and mortality, thereby imposing a huge burden on public healthcare system throughout the world. As biofilms are usually resistant to various conventional antimicrobial interventions, they may result in severe and persistent infections, which necessitates the development of novel therapeutic strategies to combat biofilm-based infections. Physicochemical modification of the biomaterials utilized in medical devices to mitigate initial microbial attachment has been proposed as a promising strategy in combating polymicrobial infections, as the adhesion of microorganisms is typically the first step for the formation of biofilms. For instance, superhydrophobic surfaces have been shown to possess substantial anti-biofilm properties attributed to the presence of nanostructures. In this article, we provide an insight into the mechanisms underlying biofilm formation and their composition, as well as the applications of nanomaterials as superhydrophobic nanocoatings for the development of novel anti-biofilm therapies.

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