Insights into coumarin-mediated inhibition of biofilm formation in <i>Salmonella</i> Typhimurium

Thakur, Samriddhi; Ray, Semanti; Jhunjhunwala, Siddharth; Nandi, Dipankar

doi:10.1080/08927014.2020.1773447

Cited by 21 publications

(17 citation statements)

References 40 publications

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“…This suggests that Coumarin reduced string formation by lowering c-di-GMP levels in strings. However, coumarin could also have other targets like quorum sensing, type III secretion system as well, raising the possibility that other factors may also be involved in this reduction (Zhang et al, 2018;Thakur et al, 2020). Strings stained positive for cellulose as judged by calcofluor staining but not planktonic single cells in M9.…”

Section: Discussionmentioning

confidence: 99%

“…We observed a 6-fold increase in c-di-GMP levels in strings under Bipd stress compared to planktonic cells in M9 (Figure 7A). To confirm the roles of c-di-GMP, we utilized Coumarin, a compound that has multiple effects but also importantly reduces intracellular c-di-GMP amounts (Zhang et al, 2018;Thakur et al, 2020). Treatment with Coumarin decreased string formation in M9 plus Bipd extensively but not planktonic growth, suggesting a potential role for c-di-GMP during string formation (Figures 7B,C).…”

Section: Strings Formation Is Dependent On the Bacterial Secondary Mementioning

confidence: 99%

“…50 µl of 2 OD cells were inoculated in 1.5 ml media and kept at 30 • C for 5 days in static condition. Biofilms were quantitated using 1% (w/v) crystal violet staining and 33% (v/v) acetic acid extraction and the absorbance was measured at 570 nm (Ray et al, 2020;Thakur et al, 2020).…”

Section: Biofilm Production and Quantitationmentioning

confidence: 99%

“…Apart from swarming motility and classical biofilms, group behavior/structures in Salmonella have not been reported extensively. Our lab has studied the various genetic and environmental factors that affect biofilm formation and stress responses by Salmonella (Kumar and Nandi, 2007;Bhosale et al, 2013;Ray et al, 2019;Ray et al, 2020;Thakur et al, 2020). While studying some stress responses, we observed macroscopic string-like structures.…”

Section: Introductionmentioning

confidence: 99%

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Multicellular String-Like Structure Formation by Salmonella Typhimurium Depends on Cellulose Production: Roles of Diguanylate Cyclases, YedQ and YfiN

et al. 2020

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Bacteria face diverse stresses in the environment and, sometimes, respond by forming multi-cellular structures, e.g., biofilms. Here, we report a novel macroscopic and multi-cellular structure formed by Salmonella Typhimurium, which resembles small strings. These string-like structures, ∼1 cm long, are induced under some stress conditions: iron deprivation by 2,2-Bipyridyl or low amounts of antibiotics or ethanol in minimal media. However, cells in strings revert back to planktonic growth upon return to nutrient rich media. Compared to planktonic cells, strings are more resistant to antibiotics and oxidative stress. Also, strains lacking csgD or rpoS, which are defective in the classical rdar biofilm formation, form strings. Furthermore, some biofilm inducing conditions do not result in strings and vice-versa, demonstrating that strings are not related to classical CsgD-dependent biofilms. Cells in a string are held together by cellulose and a strain lacking bcsA, which is defective in cellulose production, does not form strings. In addition, reductive stress conditions such as dithiothreitol (DTT) or mutations in the Disulfide bonding system (DSB) also give rise to strings. The amounts of c-di-GMP are increased upon string formation and studies with single and double deletion strains of the diguanylate cyclases, yedQ (STM1987) primarily and yfiN (STM2672) partly, revealed their importance for string formation. This is the first study showcasing the ability of Salmonella to produce high amounts of cellulose in liquid culture, instead of an interface, in a CsgD-independent manner. The relevance and possible applications of strings in the production of bacterial cellulose and bioremediation are discussed.

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Section: Discussionmentioning

confidence: 99%

Section: Strings Formation Is Dependent On the Bacterial Secondary Mementioning

confidence: 99%

Section: Biofilm Production and Quantitationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Multicellular String-Like Structure Formation by Salmonella Typhimurium Depends on Cellulose Production: Roles of Diguanylate Cyclases, YedQ and YfiN

et al. 2020

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“…The antimicrobial and anti-biofilm properties of some plant extracts have been proven by numerous studies. This activity is generally attributed to bioactive components such as terpenoids, saponins, alkaloids, and glycosides in plant extracts (Mathlouthi et al 2021 ; Ozma et al 2021 ; Thakur et al 2020 ).…”

Section: Discussionmentioning

confidence: 99%

Down-regulation of biofilm-associated genes in mecA-positive methicillin-resistant S. aureus treated with M. communis extract and its antibacterial activity

Khaleghi

Khorrami

2021

AMB Expr

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Considering the prevalence of resistance to antibiotics, the discovery of effective agents against resistant pathogens is of extreme urgency. Herein, 26 mecA-positive methicillin-resistant S. aureus (MRSA) isolated from clinical samples were identified, and their resistance to 11 antibiotics was investigated. Next, the antibacterial and anti-biofilm activity of the ethanolic extract of M. communis on these strains was evaluated. Furthermore, the effect of this extract on the expression of biofilm-associated genes, icaA, icaD, bap, sarA, and agr, was studied. According to the results, all isolated strains were multidrug-resistant and showed resistance to oxacillin and tetracycline. Also, 96.15 and 88.46 % of them were resistant to gentamicin and erythromycin. However, the extract could effectively combat the strains. The minimum inhibitory concentration (MIC) against different strains ranged from 1.56 to 25 mg/ml and the minimum bactericidal concentration (MBC) was between 3.125 and 50 mg/ml. Even though most MRSA (67 %) strongly produced biofilm, the sub-MIC concentration of the extract destroyed the pre-formed biofilm and affected the bacterial cells inside the biofilm. It could also inhibit biofilm development by significantly decreasing the expression of icaA, icaD, sarA and bap genes involved in biofilm formation and development. In conclusion, the extract inhibits biofilm formation, ruins pre-formed biofilm, and kills cells living inside the biofilm. Furthermore, it down-regulates the expression of necessary genes and nips the biofilm formation in the bud.

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Role of narL gene in the pathogenesis of Salmonella Typhimurium

Mani,

Priyadarsini,

K. Channabasappa

et al. 2023

J Basic Microbiol

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Salmonella Typhimurium (STM) is a facultative anaerobe and one of the causative agents of nontyphoidal salmonellosis (NTS). Its anaerobic metabolism is enabled under the hypoxic environment that is encountered inside macrophages and the gut lumen of the host. In both of these niches, free radicals and oxidative intermediates are released by neutrophils as an inflammatory response. These chemical species further undergo reactions to produce nitrate, which is preferably taken up by STM as an electron acceptor in the absence of oxygen. NarL, the response regulator of the two‐component regulatory system NarX/L, and a transcription factor, gets activated under anaerobic nitrate‐rich conditions and upregulates the nitrate reduction during anaerobic respiration of STM. To understand the role of NarL in the pathogenesis of STM, we generated a narL‐knockout (STM:ΔnarL) as well as a narL‐complemented strain of STM. Anaerobically, the mutant displayed no growth defect but a significant attenuation in the swimming (26%) and swarming (61%) motility, and biofilm‐forming ability (73%) in vitro, while these morphotypes got rescued upon genetic complementation. We also observed a downregulation in the expression of genes associated with nitrate reduction (narG) and biofilm formation (csgA and csgD) in anaerobically grown STM:ΔnarL. As compared with wild STM, narL mutant exhibited a threefold reduction in the intracellular replication in both intestinal epithelial cells (INT‐ 407) and monocyte‐derived macrophages of poultry origin. Further, in vivo competitive assay in the liver and spleen of the murine model showed a competitive index of 0.48 ± 0.58 and 0.403668 ± 0.32, respectively, for STM:ΔnarL.

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Insights into coumarin-mediated inhibition of biofilm formation in Salmonella Typhimurium

Cited by 21 publications

References 40 publications

Multicellular String-Like Structure Formation by Salmonella Typhimurium Depends on Cellulose Production: Roles of Diguanylate Cyclases, YedQ and YfiN

Multicellular String-Like Structure Formation by Salmonella Typhimurium Depends on Cellulose Production: Roles of Diguanylate Cyclases, YedQ and YfiN

Down-regulation of biofilm-associated genes in mecA-positive methicillin-resistant S. aureus treated with M. communis extract and its antibacterial activity

Role of narL gene in the pathogenesis of Salmonella Typhimurium

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