Cell Surface Hydrophobicity Research Articles

Anti-fungal efficacy of Carvacrol against Candida glabrata clinical isolates of vulvovaginal candidiasis

Fungal infections affect over 1 billion people worldwide each year, including superficial infections like athlete's foot and more severe systemic infections. Fungal diseases are responsible for an estimated 1.5 million deaths annually, a figure comparable to or exceeding the mortality rate of diseases like malaria or tuberculosis. The limited arsenal of available antifungal drugs, coupled with the emergence of drug-resistant fungal strains, has increased this concern. Therefore, there is a significant need to explore alternative therapeutics to overcome fungal pathogens. Carvacrol, phenolic monoterpenoids, is present in essential oils of many plants and is known for its biological and pharmacological properties. In the present study, the efficacy of carvacrol was investigated against four Candida glabrata strains isolated from patients of vulvovaginal candidiasis, which have shown varying extents of susceptibility against fluconazole. Carvacrol, a phytoactive monoterpene phenol, has shown a minimum inhibitory concentration (MIC50) ranging from 75 to 125 µg/mL and minimum fungicidal concentration of 150 and 175 µg/mL for all clinical isolates, including wild-type strains. Carvacrol, in combination with fluconazole, has shown a strong synergism against wild type C. glabrata with a FIC index value of 0.156. Preliminary mechanistic investigations unveiled that exposure to carvacrol significantly reduced cell surface hydrophobicity and ergosterol content in all strains. In conclusion, carvacrol holds promising potential as an effective antifungal agent against C. glabrata, which is categorized as high priority in the first fungal pathogen priority list of the World Health Organisation released in 2022 for highlighting priority areas for action, including the development of effective therapeutic solution.

Adhesion of Candida albicanson PTFE membranes used in guided bone regeneration.

Guided bone regeneration (GBR) is a core procedure used to regenerate bone defects. The aim of the study was to investigate the adherence of Candida albicans on six commercially available polytetrafluoroethylene (PTFE) membranes used in GBR procedures and the subsequent clinical consequences. Six commercially available PTFE membranes were tested. Two of the membranes had a textured surface and the other four a plane, nontextured one. C. albicans (ATCC 24433) was cultured for 24 h, and its cell surface hydrophobicity was assessed using a modified method. C. albicans adhesion to membrane discs was studied by scanning electron microscopy (SEM) and real-timepolymerase chain reaction (PCR). C. albicans was found to be hydrophobic (77.25%). SEM analysis showed that C. albicans adherence to all membranes examined was characterized by patchy, scattered, and small clustered patterns except for one nontextured membrane with a most rough surface in which a thick biofilm was observed. Real-timePCR quantification revealed significantly greater adhesion of C. albicans cells to PTFE membranes than the control membrane (p ≤ .001) with the membranes having a textured surface exhibiting the highestcount of 2680 × 104 cells/ml compared to the count of 707 × 104 cells/mL on those with a nontextured one (p ≤ .001). One membrane with nontextured surface, but with most rough surface was found to exhibit the highest count of 3010 × 104 cells/ml (p ≤ .05). The results of this study indicate that C. albicans adhesion on membranes' surfaces depends on the degree of surface roughness and/or on the presence of a texture. Textured PTFE membranes and/or membranes high roughness showed significantly more adhered C. albicans cells. These findings can impact the surgeon's choice of GBR membrane and postoperative maintenance.

Suppressing the virulence factors of Candida auris with baicalein through multifaceted mechanisms.

Candida auris, a rapidly spreading multi-drug-resistant fungus, is causing lethal infections under certain conditions globally. Baicalin (BE), an active ingredient extracted from the dried root of Scutellaria baicalensis Georgi, exhibits antifungal activity. However, studies have shown the distinctive advantages of Traditional Chinese medicine in combating fungal infections, while the effect of BE, an active ingredient extracted from the dried roots of Scutellaria baicalensis Georgi, on C. auris, remains unknown. Therefore, this study aims to evaluate the potential of BE as an antifungal agent against the emerging multidrug-resistant C. auris. Various assays and models, including microbroth dilution, time growth curve analysis, spot assays, adhesion tests, flocculation test, cell surface hydrophobicity assay, hydrolase activity assays, XTT assay, violet crystal assay, scanning electron microscope (SEM), confocal laser scanning microscope (CLSM), flow cytometry, Live/dead fluorescent staining, reactive oxygen species (ROS), cell wall assay, aggregation assay, porcine skin model, Galleria mellonella larvae (G. mellonella larvae) infection model, and reverse transcription-quantitative polymerase chain reaction (RT-PCR) were utilized to investigate how baicalein suppresses C. auris through possible multifaceted mechanisms. The findings indicate that BE strongly inhibited C. auris growth, adhesion, and biofilm formation. It also effectively reduced drug resistance and aggregation by disrupting the cell membrane and cell wall while reducing colonization and invasion of the host. Transcriptome analysis showed significant modulation in gene expression related to different virulence factors post-BE treatment. In conclusion, BE exhibits significant effectiveness against C. auris, suggesting its potential as a viable treatment option due to its multifaceted suppression mechanisms.

PROBIOTIC LACTIC ACID BACTERIA FROM ADUWA KO JAANR, A LESSER-KNOWN FERMENTED GINGER BEVERAGE FROM EASTERN HIMALAYAN REGION

The Eastern Himalayan natives enjoy drinking Aduwa ko jaanr, a traditionally fermented mild-alcoholic ginger brew. Studies on manufacturing process and microbiological dynamics are infrequent for Aduwa ko jaanr. Current study analyzed the probiotic properties of Lactic Acid Bacteria (LAB) associated with Aduwa ko jaanr, using in-vitro method, simulating the conditions of intestinal tract. Three LAB isolates were screened and selected for preliminary characterization (morphological and biochemical). Isolates were identified as Lactiplantibacillus argentoratensis AKJ(W), Lactiplantibacillus argentoratensis AKJ(Y), and Levilactobacillus brevis AKJ(P) by 16S rRNA sequencing. Studies on growth kinetics of stationary phase and formation times of secondary metabolites with probiotic effects were conducted. Probiotic tests, namely acid-bile tolerance, phenol tolerance, cell surface hydrophobicity, auto-aggregation property, adherence to mammalian cell line, antibiotic susceptibility, antimicrobial activity and radical scavenging activity were performed. Results indicated the isolates to have health-benefiting properties with antibiotic resistance and inhibiting human pathogens. Isolates are predicted to survive in gut environment as they tolerated high bile salt concentration (0.5%), low pH (pH2) and high phenol concentration (0.6%). Results of cell surface hydrophobicity, auto-aggregation, and mammalian cell line (HEK 293) adherence tests suggested that isolates could adhere and possibly colonize intestine's inner wall. High radical scavenging activity of isolates suggested overall antioxidant property of the fermented beverage. MAR index showed isolates’ resistance to different antibiotics, indicating that their action is unaffected even when administered during illness. The present study suggests that LAB in Aduwa ko jaanr has potential probiotic properties which makes it an appropriate traditional beverage conferring health benefits.

Biogenic amine tryptamine in human vaginal probiotic isolates mediates matrix inhibition and thwarts uropathogenic E. coli biofilm

Probiotics offer a promising prophylactic approach against various pathogens and represent an alternative strategy to combat biofilm-related infections. In this study, we isolated vaginal commensal microbiota from 54 healthy Indian women to investigate their probiotic traits. We primarily explored the ability of cell-free supernatant (CFS) from Lactobacilli to prevent Uropathogenic Escherichia coli (UPEC) colonization and biofilm formation. Our findings revealed that CFS effectively reduced UPEC’s swimming and swarming motility, decreased cell surface hydrophobicity, and hindered matrix production by downregulating specific genes (fimA, fimH, papG, and csgA). Subsequent GC–MS analysis identified Tryptamine, a monoamine compound, as the potent bioactive substance from Lactobacilli CFS, inhibiting UPEC biofilms with an MBIC of 4 µg/ml and an MBEC of 8 µg/ml. Tryptamine induced significant changes in E. coli colony biofilm morphology, transitioning from the Red, Dry, and Rough (RDAR) to the Smooth and White phenotype, indicating reduced extracellular matrix production. Biofilm time-kill assays demonstrated a four-log reduction in UPEC viability when treated with Tryptamine, highlighting its potent antibacterial properties, comparable to CFS treatment. Biofilm ROS assays indicated a significant elevation in ROS generation within UPEC biofilms, suggesting a potential antibacterial mechanism. Gene expression studies with Tryptamine-treated samples showed a reduction in expression of curli gene (csgA), consistent with CFS treatment. This study underscores the potential of Tryptamine from probiotic Lactobacilli CFS as a promising antibiofilm agent against UPEC biofilms.

Limosilactobacillus fermentum MYSY8, a Potential Probiotic Isolate from Fermented Rice Beverage for the Control of Microsporum canis

ABSTRACT Growing concerns about controlling dermatophytes due to antifungal drug toxicity and resistance are leading to increased interest in using probiotics to combat skin infections. Our study focussed on evaluating the probiotic and antifungal attributes of the lactic acid bacteria Limosilactobacillus fermentum LfMYSY8 isolated from fermented rice beverage of India, Haria, to impede the growth of Microsporum canis, a common dermatophyte. The isolate showed promising probiotic characteristics like acid tolerance (44.71% at pH 2), bile tolerance (63.40%), cell surface hydrophobicity (43.26%), a strong auto-aggregation ability (74.5%), osmotic stress tolerance, antibacterial activity, and antibiotic susceptibility. While testing the antifungal efficacy, the cells and the cell-free supernatant (CFS) of the isolate inhibited M. canis growth with an average 98% biomass reduction. Substantial reduction in conidial germination and disruption of hyphal structure was observed. CFS characterization revealed that the organic acid metabolites were responsible for anti-fungal activity. Therefore, potential exists for using this strain to control skin infections.

Antimicrobial effect of combined preservatives using chestnut inner shell, cinnamon, and ε-poly-lysine against food-poisoning bacteria Staphylococcus aureus.

Chestnut inner shell, cinnamon, and ε-poly-lysine (ε-PL) have been used for natural preservative of food grade, and combined preservatives (CP) has been formulated previously. This study examined whether Staphylococcus aureus growth could be controlled using CP in tryptic soy broth (TSB). CP inhibited S. aureus growth by about 5 log CFU/mL in TSB. The cell surface hydrophobicity, autoaggregation, and motility of S. aureus were slightly reduced by CP treatment. The expression of adhesion- and toxin-related genes in S. aureus treated with CP was reduced than that in the control treated with TSB. In addition, the inhibitory activity of the CP was visible through the SEM images. Therefore, the CP consisted of chestnut inner shell extract, cinnamon extract, and ε-PL had appropriate antibacterial effect against S. aureus and could be applied as antibacterial agents.

Antibiofilm activity of d-limonene against spoilage Bacillus amyloliquefaciens

This study aimed to determine the efficacy of d-limonene in preventing biofilm formation by Bacillus amyloliquefaciens, a soy food spoilage bacterium. The minimal biofilm inhibitory concentrations (MBICs) of d-limonene against two strains of B. amyloliquefaciens were determined using a twofold dilution method. Furthermore, the ability of d-limonene to eradicate preformed biofilms was evaluated using the TTC reduction method. Subsequent analyses investigated the effects of d-limonene on biofilm morphology, cell motility, cell surface characteristics, and the composition of the biofilm matrix. The MBICs of d-limonene for B. amyloliquefaciens strains DY1a and DY1b were determined to be 24 and 36 μL/mL, respectively. At 2 MBIC, d-limonene eradicated 63.67% of the DY1a biofilms and 52.63% of the DY1b biofilms. Significantly, d-limonene markedly reduced swimming and swarming motility at concentrations ranging from 1/2 to 1 MBIC. In particular, at 1/2 MBIC, d-limonene decreased swimming and swarming abilities by 85.88% and 37.84%, respectively, for strain DY1a and by 75.00% and 95.07%, respectively, for strain DY1b. Furthermore, d-limonene suppressed the biosynthesis of polysaccharides and proteins in the extracellular biofilm matrix and reduced cell surface hydrophobicity, surface charge, and autoaggregation. These findings suggest that d-limonene could be an effective antibiofilm agent for the control of B. amyloliquefaciens in the soybean food industry.

Lactic Acid Bacteria from Bombyx mori Frass: Probiotic Properties and Antagonistic Activities

Insect farming is gaining attention as a promising area for exploring probiotic bacteria, which can benefit both insect health and various industries. Silkworm farming is a key industry in Thailand; however, challenges such as disease susceptibility and optimising growth require innovative solutions for sustainable practices. Our study addresses this by assessing lactic acid bacteria (LAB) in native Thai silkworm faeces, which accumulate as natural by-products during the rearing process. We conducted biochemical tests, including those for catalase, haemolytic activity, bile salt tolerance, antimicrobial activity, antibiotic susceptibility, and cell surface hydrophobicity, along with taxonomic classification. Out of 102 isolates, eight potential probiotics were selected, with five showing strong probiotic traits like acid and bile salt tolerance and cell surface hydrophobicity, enhancing gut survivability. These isolates also displayed antagonistic activity against pathogens like Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, and Pseudomonas aeruginosa. Safety assessments confirmed their safety, with no haemolytic activity and sensitivity to antibiotics like chloramphenicol and amoxicillin. These LAB isolates (SP04, SP06, SP44, SP64, and SP67), identified as Enterococcus faecalis strain NBRC 100481, show promise as in vitro probiotics for silkworm rearing, calling for further in vivo evaluation.

БИОТЕХНОЛОГИЧЕСКИЙ ПОТЕНЦИАЛ НОВЫХ ШТАММОВ УГЛЕВОДОРОДОКИСЛЯЮЩИХ БАКТЕРИЙ

The ingress of oil has a depressing effect on the soil biocenosis, which is enhanced in the presence of other pollutants (heavy metals, chlorides, herbicides), which ultimately leads to the withdrawal of significant land areas (including agricultural ones) from the target turnover. For the bioremediation of such areas, oil-degrading microorganisms are needed that are resistant to additional pollutants, as well as a set of useful properties that increase the efficiency of cleaning and restoring disturbed soils. In this work, three isolates were isolated that actively grew in a liquid medium containing oil. As a result of sequencing the nucleotide sequence of the 16S rRNA gene, it was reliably established that all strains belong to the species Acinetobacter calcoaceticus . The bacteria showed a high oil-oxidizing ability (89.7-97.0%), which was assessed by the degree of destruction of the aliphatic fraction, including in the presence of herbicides based on 2,4-dichlorophenoxyacetic acid (Octapon extra), imazethapyr (Tapir) and tribenuron-methyl ( Special forces) (degree of biodestruction 40.4-54.1%). Microorganisms used aromatic hydrocarbons (including polycyclic ones) as a carbon source. They demonstrated high cell surface hydrophobicity (78-85%) with respect to hexadecane and exhibited emulsifying activity of more than 50%. The bacteria were tolerant to the herbicides Tapir and Spetsnaz in amounts up to 1% volume (mass). The herbicide Octapon extra was more toxic to bacteria - the growth of all strains occurred at its concentration in the medium not higher than 0.5% volume. Microorganisms showed resistance to sodium chloride in an amount of 3.0-5.0% and lead ions (1.00-1.25 g/l). They produced the enzyme lipase and were capable of fixing atmospheric nitrogen and dissolving inorganic phosphate (including in the presence of oil or herbicides). The studied Acinetobacter spp. stimulated the growth of barley (aboveground and underground parts), especially the A. calcoaceticus strain P32 (elongation of shoots and roots by 15.3 and 49.5%, respectively). The data obtained indicate that all three strains have certain prospects for use in the purification of complexly contaminated soils.

Mechanism and bioinformatics analysis of the effect of berberine-enhanced fluconazole against drug-resistant Candida albicans

Biofilms produced by Candida albicans present a challenge in treatment with antifungal drug. Enhancing the sensitivity to fluconazole (FLC) is a reasonable method for treating FLC-resistant species. Moreover, several lines of evidence have demonstrated that berberine (BBR) can have antimicrobial effects. The aim of this study was to clarify the underlying mechanism of these effects. We conducted a comparative study of the inhibition of FLC-resistant strain growth by FLC treatment alone, BBR treatment alone, and the synergistic effect of combined FLC and BBR treatment. Twenty-four isolated strains showed distinct biofilm formation capabilities. The antifungal effect of combined FLC and BBR treatment in terms of the growth and biofilm formation of Candida albicans species was determined via checkerboard, time-kill, and fluorescence microscopy assays. The synergistic effect of BBR and FLC downregulated the expression of the efflux pump genes CDR1 and MDR, the hyphal gene HWP1, and the adhesion gene ALS3; however, the gene expression of the transcriptional repressor TUP1 was upregulated following treatment with this drug combination. Furthermore, the addition of BBR led to a marked reduction in cell surface hydrophobicity. To identify resistance-related genes and virulence factors through genome-wide sequencing analysis, we investigated the inhibition of related resistance gene expression by the combination of BBR and FLC, as well as the associated signaling pathways and metabolic pathways. The KEGG metabolic map showed that the metabolic genes in this strain are mainly involved in amino acid and carbon metabolism. The metabolic pathway map showed that several ergosterol (ERG) genes were involved in the synthesis of cell membrane sterols, which may be related to drug resistance. In this study, BBR + FLC combination treatment upregulated the expression of the ERG1, ERG3, ERG4, ERG5, ERG24, and ERG25 genes and downregulated the expression of the ERG6 and ERG9 genes compared with fluconazole treatment alone (p < 0.05).

Monitoring probiotic properties and safety evaluation of antilisterial Enterococcus faecium strains with cholesterol-lowering potential from raw Cow's milk

Enterococci are an important member of lactic acid bacteria due to their presence in fermented foods, tolerance to low pH and bile salts, bile salt hydrolase (BSH) activity, reducing cholesterol, and producing bacteriocin. However, probiotic and safety issues of enterococci are still debated. It is important to investigate probiotic properties and safety evaluation of these genus because they are intentionally or unintentionally present in foods. In this study, probiotic properties (tolerance to bile salts and simulated gastric juice, antimicrobial and BSH activity, cholesterol lowering potential, auto/co-aggregation, and cell surface hydrophobicity) and safety evaluation (antibiotic resistance, virulence factor, haemolysis and DNase activity, Galleria mellonella infection model, gelatinase activity, and biofilm formation) of Enterococcus faecium (E. faecium) BH04, BH12, BH84, and BH99 isolated raw cow's milk were determined. All strains had high tolerance to bile salts (47.70%–103.84%) and simulated gastric juice (76.80%–82.05%), and antimicrobial activity on L. monocytogenes ATCC 7644 by protein-like substances such as bacteriocin. The strains had strong BSH property and reduced cholesterol by 69.47%–95.00%. The strains were resistant only to gentamicin, kanamycin, and streptomycin and did not have haemolysis and DNase activity. Only gelE and esp genes were detected in some strains. According to the results, it is thought that the E. faecium strains could be possible probiotic candidates. Moreover, this study is the first report on Enterococcus faecium strains isolated from raw cow's milk, which tolerate to bile salt and simulated gastric juice, have BSH potential and antimicrobial activity by protein-like substances, and reduce cholesterol level.

Impacts of ohmic-heating on the surface characteristics, membrane integrity, morphology, and chemical compounds of Bifidobacterium animalis paraprobiotic

The aim of this paper was to obtain paraprobiotic from Bifidobacterium animalis subsp. lactis Bb-12 (BB) with a promising ohmic-heating (OH) condition through response surface modeling, based on the flow cytometry and spectrophotometry analyses. Some properties of the obtained BB paraprobiotic (BBP) were studied, including the cell surface hydrophobicity (CSH), cell auto- and co-aggregation (CAA and CCA), and membrane integrity (MI). Among fitted models, the linear model was more accurate for co-aggregation (R2-pred 85.77%), and the quadratic model for CSH (R2-pred: 84.17%), auto-aggregation (R2-pred=87.25%), MI (R2-pred: 83.65%). The electric field (EF) had the most destructive effect on the MI of BBP. However, OH temperature had the most enhancing effect on the surface characteristics. The surface characteristics of BBP (CSH: 44.82, CAA: 38.05, and CCA: 40.79) obtained by the OH process at optimum condition was remarkably more than BB without OH treatment (CSH: 34.21, CAA: 27.18, and CCA: 28.5). The confirming analysis regarding the MI changes was performed successfully by scanning electron microscopy analysis. Lactic and acetic acids were the most amounts of characterized metabolites in BBP and BB. The OH condition, including EF of 8 V/cm, OH temperature of 88˚C, BB population of 8 (log CFU/mL), and OH time of 3 min, were considered optimum condition. At this optimum OH condition, the responses for CSH, CAA, CCA, and MI were observed 44.82, 38.05, 40.79, and 94.82 %, respectively.

The use of organic peroxyacids for the inactivation of calcium-mediated biofilm formation by Bacillus licheniformis

Biofilms formed by Bacillus licheniformis usually serve as a continuous bacterial contamination in the dairy industry. The purpose of this study was to explore how 1% organic acids (citric acid, phenyllactic acid, malic acid, and butyric acid) and their 1% organic peroxyacids (peroxycitric acid, peroxyphenyllactic acid, peroxymalic acid, and peroxybutyric acid) can inactive the planktonic and biofilm cells of B. licheniformis. Results demonstrated that the number of B. licheniformis planktonic cells was increased from 4 to 6.46 Log CFU mL−1 when treated with water. Organic peroxyacids, especially peroxyphenyllactic acid (PPA), obviously inactivated planktonic cells of B. licheniformis by a range of 3.32–4.14 Log CFU mL−1. Moreover, organic peroxyacids could also decrease the cell surface hydrophobicity of bacteria, and effectively control the Ca2+-mediated biofilm formation by B. licheniformis in 96-well plates (reduction of OD values by 0.14–0.33) and on stainless steel (reduction of cell counts by 1.20–2.49 Log CFU cm−2). The low minimum biofilm eradication concentration of PPA (0.125%) also suggests its strong biofilm inactivation activity, which could serve as a novel and environmentally friendly biofilm control agent in the dairy industry.

Putative Probiotic Ligilactobacillus salivarius Strains Isolated from the Intestines of Meat-Type Pigeon Squabs.

This study aims to screen for potential probiotic lactic acid bacteria from the intestines of meat-type pigeon squabs. Ligilactobacillus salivarius YZU37 was identified as the best comprehensive performed strain. Being acid- and bile salt-tolerant, it displayed growth-inhibition activities against Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, and Salmonella typhimurium SL1344, exhibited sensitivity to 6 commonly used antibiotics, and endowed with good cell surface hydrophobicity, auto-aggregation property, and anti-oxidant activities. Results of in vitro experiments indicated that the bacteriostatic effects of this strain were related to the production of proteinaceous substances that depend on acidic conditions. Whole-genome sequencing of L. salivarius YZU37 was performed to elucidate the genetic basis underlying its probiotic potential. Pangenome analysis of L. salivarius YZU37 and other 212 L. salivarius strains available on NCBI database revealed a pigeon-unique gene coding choloylglycine hydrolase (CGH), which had higher enzyme-substrate binding affinity than that of the common CGH shared by L. salivarius strains of other sources. Annotation of the functional genes in the genome of L. salivarius YZU37 revealed genes involved in responses to acid, bile salt, heat, cold, heavy metal, and oxidative stresses. The whole genome analysis also revealed the absence of virulence and toxin genes and the presence of 65 genes distributed under 4 CAZymes classes, 2 CRISPR-cas regions, and 3 enterolysin A clusters which may confer the acid-dependent antimicrobial potential of L. salivarius YZU37. Altogether, our results highlighted the probiotic potential of L. salivarius YZU37. Further in vivo investigations are required to elucidate its beneficial effects on pigeons.

Phenotypic and molecular characterization of clinically isolated antibiotics-resistant S. aureus (MRSA), E. coli (ESBL) and Acinetobacter 1379 bacterial strains.

Antibiotic-resistant bacteria causing nosocomial infections pose a significant global health concern. This study focused on examining the lipid profiles of both non-resistant and clinically resistant strains of Staphylococcus aureus (MRSA 1418), E. coli (ESBL 1384), and Acinetobacter 1379. The main aim was to investigate the relationship between lipid profiles, hydrophobicity, and antibiotic resistance so as to identify the pathogenic potential and resistance factors of strains isolated from patients with sepsis and urinary tract infections (UTIs). The research included various tests, such as antimicrobial susceptibility assays following CLSI guidelines, biochemical tests, biofilm assays, and hydrophobicity assays. Additionally, gas chromatography mass spectrometry (GC-MS) and GC-Flame Ionization Detector (GC-FID) analysis were used for lipid profiling and composition. The clinically isolated resistant strains (MRSA-1418, ESBL-1384, and Acinetobacter 1379) demonstrated resistance phenotypes of 81.80%, 27.6%, and 63.6%, respectively, with a multiple antibiotic resistance index of 0.81, 0.27, and 0.63. Notably, the MRSA-1418 strain, which exhibited resistance, showed significantly higher levels of hemolysin, cell surface hydrophobicity, biofilm index, and a self-aggregative phenotype compared to the non-resistant strains. Gene expression analysis using quantitative real-time PCR (qPCR). Indicated elevated expression levels of intercellular adhesion biofilm-related genes (icaA, icaC, and icaD) in MRSA-1418 (pgaA, pgaC, and pgaB) and Acinetobacter 1379 after 24h compared to non-resistant strains. Scanning electron microscopy (SEM) was employed for structural investigation. These findings provide valuable insights into the role of biofilms in antibiotic resistance and suggest potential target pathways for combating antibiotic-resistant bacteria.

Evaluation of functional properties of lactic acid bacteria isolated from traditional cheese

The objective of this research was to study a total of 10 strains of lactic acid bacteria previously isolated from traditional cheese, explore the effects of various in vitro tests, and evaluate their functional and potential probiotic properties. We tested the strains for cholesterol assimilation, antimicrobial activity, enzyme and exopolysaccharides (EPS) production, cell surface traits, antibiofilm, and tolerance to lysozyme and phenol. E. faecalis S135 and E. durans S1121 were characterized by strong antibacterial activities against C. albicans and S. aureus. The strains E. durans S092 and E. faecalis S135 were differentiated by phytase-producing and coagulation activity, respectively. Moreover, E. faecalis S135 had a greater cholesterol reduction percentage (66.6 ± 0.00 %) than the others. Separately, E. durans S104 and L. coryniformis subsp. torquens S232 were found to possess stronger cell surface properties, e.g., auto-aggregation (94.3 ± 0.30 %) and cell surface hydrophobicity (65.1 ± 0.11 %). All LAB 10 strains were able to handle 0.4 % phenol and 2 mg/mL lysozyme well. They also had some antibiofilm activity, but not much EPS production. Industrially important strains with antimicrobial activity, such as E. durans (S1121, S092, and S104) and E. faecalis S135, could serve as bio-protective agents. These four strains can therefore find application in various fields, including the production of fermented and/or functional foods and enzymes.

Plant-derived bioactive compounds for the inhibition of biofilm formation: a comprehensive review.

Biofilm formation is a widespread phenomenon that impacts different fields, including the food industry, agriculture, health care and the environment. Accordingly, there is a serious need for new methods of managing the problem of biofilm formation. Natural products have historically been a rich source of varied compounds with a wide variety of biological functions, including antibiofilm agents. In this review, we critically highlight and discuss the recent progress in understanding the antibiofilm effects of several bioactive compounds isolated from different plants, and in elucidating the underlying mechanisms of action and the factors influencing their adhesion. The literature shows that bioactive compounds have promising antibiofilm potential against both Gram-negative and Gram-positive bacterial and fungal strains, via several mechanisms of action, such as suppressing the formation of the polymer matrix, limiting O2 consumption, inhibiting microbial DNA replication, decreasing hydrophobicity of cell surfaces and blocking the quorum sensing network. This antibiofilm activity is influenced by several environmental factors, such as nutritional cues, pH values, O2 availability and temperature. This review demonstrates that several bioactive compounds could mitigate the problem of biofilm production. However, toxicological assessment and pharmacokinetic investigations of these molecules are strongly required to validate their safety.

Co-encapsulation of Lactiplantibacillus plantarum NCIM 2083 with resveratrol for improved bioaccessibility

Numerous research studies have recently focused on the benefits of co-delivering nutraceuticals and probiotics. The current study aimed to optimize and characterize the properties of the probiotic-nutraceutical formulation and to explore their combined effect in terms of stability and functionality. A combination of nutraceutical - resveratrol (RSV) and probiotics - Lactiplantibacillus plantarum NCIM 2083 (LP) as an active compound and whey protein (WP) as a matrix material were selected for this study. Different formulations of WP:RSV:LP were co-encapsulated using conductive hydro drying (CHD) at different water temperatures (40, 50, and 60 °C) of the dryer reservoir. Overall, the formulation of WP:RSV:LP (15:0.5:0.5) dried at 50 °C was optimized with lesser moisture content (3.53% ± 0.30% d.b.), better yield (90.63% ± 0.97%), higher encapsulation efficiency (80.85 ± 2.57 and 84.29% ± 2.63% of RSV and LP, respectively), good radical-scavenging activity (74.92% ± 1.54%), increased in-vitro release (49.47% ± 3.59%), enhanced cell surface hydrophobicity (CSH) with retained adhesion ability, and improved bioaccessibility of RSV (48.30% ± 2.75%) and probiotic survivability (79.86% with 7.02 ± 0.45 log10 CFU/g) under digestion conditions. Thus, the study results confirmed that the RSV-LP combination showed positive effects on each other.

Assessing Metschnikowia pulcherrima as a potential probiotic yeast for animal feed

Abstract In response to escalating antimicrobial resistance fuelled by their extensive use in livestock farming, this study explores alternative strategies in animal health management. We investigated the probiotic potential of Metschnikowia pulcherrima strains 4 × 3, DH5, ICS1 and QRI1 for their suitability in poultry environments. Our research demonstrated that previously discovered antimicrobial M. pulcherrima strains exhibit promising probiotic behaviours, including biofilm production, auto-aggregation, cell surface hydrophobicity, adhesion to Caco-2 cells, antioxidant capacity, and resilience to gastric stresses. Notable findings include DH5 exhibiting the highest biofilm formation, 4 × 3 and DH5 showing rapid auto-aggregation, 4 × 3 and ICS1 displaying high cell surface hydrophobicity, and all strains demonstrating considerable adherence to Caco-2 cells. 4 × 3 also exhibited exceptional bile tolerance, while ICS1 showed robust survival under simulated gastrointestinal conditions. These traits suggest M. pulcherrima’s capacity to colonise the poultry gastrointestinal tract, promote animal health, and support more sustainable livestock practices as a potential alternative to conventional antibiotics.