Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21.514
Filter
1.
Biomaterials ; 312: 122739, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39096840

ABSTRACT

The biofilm-induced "relatively immune-compromised zone" creates an immunosuppressive microenvironment that is a significant contributor to refractory infections in orthopedic endophytes. Consequently, the manipulation of immune cells to co-inhibit or co-activate signaling represents a crucial strategy for the management of biofilm. This study reports the incorporation of Mn2+ into mesoporous dopamine nanoparticles (Mnp) containing the stimulator of interferon genes (STING) pathway activator cGAMP (Mncp), and outer wrapping by M1-like macrophage cell membrane (m-Mncp). The cell membrane enhances the material's targeting ability for biofilm, allowing it to accumulate locally at the infectious focus. Furthermore, m-Mncp mechanically disrupts the biofilm through photothermal therapy and induces antigen exposure through photodynamic therapy-generated reactive oxygen species (ROS). Importantly, the modulation of immunosuppression and immune activation results in the augmentation of antigen-presenting cells (APCs) and the commencement of antigen presentation, thereby inducing biofilm-specific humoral immunity and memory responses. Additionally, this approach effectively suppresses the activation of myeloid-derived suppressor cells (MDSCs) while simultaneously boosting the activity of T cells. Our study showcases the efficacy of utilizing m-Mncp immunotherapy in conjunction with photothermal and photodynamic therapy to effectively mitigate residual and recurrent infections following the extraction of infected implants. As such, this research presents a viable alternative to traditional antibiotic treatments for biofilm that are challenging to manage.


Subject(s)
Biofilms , Indoles , Membrane Proteins , Polymers , Biofilms/drug effects , Polymers/chemistry , Animals , Indoles/chemistry , Indoles/pharmacology , Mice , Membrane Proteins/metabolism , Nanoparticles/chemistry , Photochemotherapy/methods , Porosity , Macrophages/metabolism , Macrophages/drug effects , Reactive Oxygen Species/metabolism , Female , Signal Transduction/drug effects , Photothermal Therapy , Myeloid-Derived Suppressor Cells/metabolism , Myeloid-Derived Suppressor Cells/drug effects , Mice, Inbred C57BL
2.
Methods Mol Biol ; 2852: 135-141, 2025.
Article in English | MEDLINE | ID: mdl-39235741

ABSTRACT

When submitted to environmental stresses, bacteria can modulate its fatty acid composition of membrane phospholipids in order to optimize membrane fluidity. Characterization of bacterial membrane fatty acid profiles is thus an interesting indicator of cellular physiological state. The methodology described here aims to improve the recovering of biofilm cells for the characterization of their fatty acid profiles. The saponification reagent is directly applied on the whole biofilm before the removal of cells from the inert surface. In this way, maximum of the cells and their fatty acids can be recovered from the deepest layers of the biofilm.


Subject(s)
Biofilms , Cell Membrane , Fatty Acids , Biofilms/growth & development , Fatty Acids/metabolism , Cell Membrane/metabolism , Bacteria/metabolism , Phospholipids/metabolism , Membrane Fluidity
3.
Methods Mol Biol ; 2852: 143-158, 2025.
Article in English | MEDLINE | ID: mdl-39235742

ABSTRACT

Like most microorganisms, important foodborne pathogenic bacteria, such as Salmonella enterica, Listeria monocytogenes, and several others as well, can attach to surfaces, of either abiotic or biotic nature, and create biofilms on them, provided the existence of supportive environmental conditions (e.g., permissive growth temperature, adequate humidity, and nutrient presence). Inside those sessile communities, the enclosed bacteria typically present a gene expression profile that differs from the one that would be displayed by the same cells growing planktonically in liquid media (free-swimming cells). This altered gene expression has important consequences on cellular physiology and behavior, including stress tolerance and induction of virulence. In this chapter, the methodology to use reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to monitor and comparatively quantify expression changes in preselected genes of bacteria between planktonic and biofilm growth modes is presented.


Subject(s)
Biofilms , Plankton , Biofilms/growth & development , Plankton/genetics , Gene Expression Regulation, Bacterial , Food Microbiology , Gene Expression Profiling/methods , Real-Time Polymerase Chain Reaction/methods , Bacteria/genetics , Listeria monocytogenes/genetics , Listeria monocytogenes/physiology , Reverse Transcriptase Polymerase Chain Reaction/methods
4.
Methods Mol Biol ; 2852: 159-170, 2025.
Article in English | MEDLINE | ID: mdl-39235743

ABSTRACT

The functional properties of biofilms are intimately related to their spatial architecture. Structural data are therefore of prime importance to dissect the complex social and survival strategies of biofilms and ultimately to improve their control. Confocal laser scanning microscopy (CLSM) is the most widespread microscopic tool to decipher biofilm structure, enabling noninvasive three-dimensional investigation of their dynamics down to the single-cell scale. The emergence of fully automated high content screening (HCS) systems, associated with large-scale image analysis, has radically amplified the flow of available biofilm structural data. In this contribution, we present a HCS-CLSM protocol used to analyze biofilm four-dimensional structural dynamics at high throughput. Meta-analysis of the quantitative variables extracted from HCS-CLSM will contribute to a better biological understanding of biofilm traits.


Subject(s)
Biofilms , Microscopy, Confocal , Biofilms/growth & development , Microscopy, Confocal/methods , Food Microbiology/methods , Imaging, Three-Dimensional/methods , Foodborne Diseases/microbiology , High-Throughput Screening Assays/methods , Image Processing, Computer-Assisted/methods
5.
Microb Pathog ; 195: 106902, 2024 Aug 31.
Article in English | MEDLINE | ID: mdl-39218374

ABSTRACT

Mastitis remains a paramount economic threat to dairy livestock, with antibiotic resistance severely compromising treatment efficacy. This study provides an in-depth investigation into the multidrug resistance (MDR) mechanisms in bacterial isolates from bovine mastitis, emphasizing the roles of antimicrobial resistance genes (ARGs), biofilm formation, and active efflux systems. A total of 162 Staphylococci, eight Escherichia coli, and seven Klebsiella spp. isolates were obtained from 215 milk samples of clinical and subclinical mastitis cases. Antibiotic susceptibility testing identified Twenty Staphylococci (12.35 %), six E. coli (75 %) and seven Klebsiella (100 %) identified as MDR displaying significant resistance to ß-lactams and tetracyclines The Multiple Antibiotic Resistance (MAR) index of these isolates ranged from 0.375 to 1.0, highlighting extensive resistance. Notably, 29 of the 33 MDR isolates produced biofilms on Congo red agar, while all exhibited biofilm formation in the Microtitre Plate assay. Critical ARGs (blaZ, blaTEM, blaCTX-M, tetM, tetA, tetB, tetC, strA/B, aadA) and efflux pump genes (acrB, acrE, acrF, emrB, norB) regulating active efflux were identified. This pioneering study elucidates the synergistic contribution of ARGs, biofilm production, and efflux pump activity to MDR in bovine mastitis pathogens. To our knowledge, this comprehensive study is the first of its kind, offering novel insights into the complex resistance mechanisms. The findings underscore the imperative need for advanced antibiotic stewardship and strategic interventions in dairy farming to curb the rise of antibiotic-resistant infections, thereby protecting both animal and public health.

6.
Bioresour Technol ; 412: 131406, 2024 Aug 31.
Article in English | MEDLINE | ID: mdl-39222863

ABSTRACT

Microalgae as a promising approach for wastewater treatment, has challenges in directly treating digested piggery wastewater (DPW) with high ammonia nitrogen (NH4+-N) concentration. To improve the performance of microalgae in DPW treatment, straw was employed as a substrate to form a straw-microalgae biofilm. The results demonstrated that the straw-microalgae biofilm achieved the highest NH4+-N removal rate of 193.2 mg L-1 d-1, which was 28.8 % higher than that of culture system without straw. The final NH4+-N concentration in the effluent met the discharge standard of 5 mg L-1. Furthermore, the total organic carbon (TOC) released from straw facilitated bacterial proliferation and the secretion of extracellular polymeric substances (EPS). The EPS and TOC increased the suspension viscosity and surface tension, thereby enhancing the residence time of CO2 in the liquid phase and promoting CO2 fixation. This study presented a novel method for the biological treatment of high-ammonia-nitrogen DPW.

7.
J Hazard Mater ; 480: 135780, 2024 Sep 10.
Article in English | MEDLINE | ID: mdl-39259996

ABSTRACT

Microplastics (MPs) and per- and polyfluoroalkyl substances (PFASs) coexist widely in lakes and affect ecological security. The coexistence characteristics and adsorption-desorption mechanisms between MPs and typical PFASs were explored in a typical eutrophic shallow lake (Taihu Lake). Polyvinyl chloride (PVC) and polyethylene (PE) are the primary types of MPs in Taihu Lake, with average abundances in water and sediment of 18630 n/m3 and 584 n/kg, respectively. The average concentrations of PFASs in water and sediment are 288.93 ng/L and 4.33 ng/g, with short-chain PFASs (C4-C7) being the main pollutants. Perfluorobutanoic acid (PFBA) in both water and sediment contributed 38.48 % and 44.53 %, respectively, followed by hexafluoropropylene oxide dimer acid (HFPO-DA). The morphological characteristics of MPs influence the distribution of long-chain PFAS in lake water, while the presence of HFPO-DA and perfluorohexanoic acid (PFHxA) in sediment is directly linked to the concentration and size of MPs. A combination of field investigations and indoor experiments revealed that the irreversible adsorption characteristics between MPs and HFPO-DA may promote the high cumulative flux of HFPO-DA in sediment, and the biofilm on the surface of MPs significantly accelerates this accumulation process. The results provide a new perspective on the co-transport behavior of emerging pollutants in aquatic environments.

8.
Sci Total Environ ; : 176176, 2024 Sep 09.
Article in English | MEDLINE | ID: mdl-39260502

ABSTRACT

Density gradient columns are an established industrial method for measuring the density of plastics, but have rarely been applied to environmental plastics. In this study 14 density gradient columns were used to measure the density of 150 environmental plastics particles from an urban beach, plus 100 microplastics of known identity, representing what is believed to be the most extensive density dataset for environmental plastic debris available in scientific literature. In total, 92 % of investigated particles had their density measured, with the remainder falling outside of the range of the density columns: 800-1418 kg·m-3. Error values for individual plastic particles were conservatively estimated as ≤0.27 kg·m-3, equating to the density difference associated with a distance of 1 mm in the density gradient column. Moreover, error values for plastics of known identity, based on the standard deviation of five different particles of the same polymer type, were generally low, ≤±â€¯1.78 kg·m-3 for 75 % of polymers. The most notable exception was crumb rubber from used tyres, with a density of 1204.84 ±â€¯105.87 kg·m-3, reflecting a heterogenous material. The majority of environmental plastics were polyethylene pellets, with densities from 823.47 to 1143.47 kg·m-3, a much wider range than reported in literature for this polymer. The densest environmental pellet was biologically attached to a stone-like particle. Otherwise, there was no evidence that environmental processing, in the form of biofilm growth or weathering, was driving variability in density. Most pellets with extremely high or low density were coloured, indicating that additives or impurities introduced during manufacturing altered the density of the virgin resin. Overall, density gradient columns show great promise for improving our knowledge of microplastic density. They represent an accurate and efficient high-throughput method, which can measure the density of ~40 microplastics simultaneously over relatively short time periods.

9.
Article in English | MEDLINE | ID: mdl-39261139

ABSTRACT

Vascular graft infections (VGI) pose a significant challenge in vascular surgery, characterized by substantial morbidity and mortality. This review delves into the epidemiology, pathogenesis, microbiology, risk factors, and clinical presentation of VGI. It highlights diagnostic criteria and methodologies, including imaging techniques and laboratory tests. Comprehensive management strategies, involving antimicrobial therapy, surgical intervention, and preventive measures, are discussed. Emphasis is placed on the multidisciplinary approach required for effective treatment, alongside emerging trends in VGI microbiology and innovative therapeutic options. This review article aims to provide a detailed understanding of VGI for improved clinical outcomes.

10.
Arch Microbiol ; 206(10): 402, 2024 Sep 11.
Article in English | MEDLINE | ID: mdl-39261342

ABSTRACT

A global water crisis is emerging due to increasing levels of contaminated water and decreasing clean water supply on Earth. This study aims to address the removal of azo dye from wastewater to enable its reuse. Recently, utilizing microorganisms has been proven to be a practical choice for the remediation of azo dyes in wastewater. Hence, in this study, we employed a preformed biofilm of Pseudomonas aeruginosa on a solid support (called substrate) to degrade azo dyes. This process offers several advantages, such as stability, substrate portability, more biofilm production in less time, and efficient utilization of enzymes for remediation. From 50 ppm of initial Congo Red concentration, 75.74% decolorization was achieved within ten h using a preformed biofilm on a coverslip. A maximum of 52.27% decolorization was achieved using biofilm during its formation after 72 h of incubation. The Fourier-transform infrared (FTIR) spectroscopic analysis of Congo Red dye before and after remediation revealed a significant change in peak intensity, indicating dye degradation. Phytotoxicity studies performed by seed germination with Vigna radiata revealed that, after 5-7 days, almost 40% more seeds with longer root and shoot lengths were germinated in the presence of treated dye compared to the untreated one. This data indicated that the harmful Congo Red was successfully degraded to a non-toxic product by Pseudomonas aeruginosa biofilm grown on a glass substrate.


Subject(s)
Biodegradation, Environmental , Biofilms , Congo Red , Pseudomonas aeruginosa , Biofilms/growth & development , Congo Red/metabolism , Pseudomonas aeruginosa/physiology , Pseudomonas aeruginosa/metabolism , Wastewater/microbiology , Water Pollutants, Chemical/metabolism , Spectroscopy, Fourier Transform Infrared , Coloring Agents/metabolism , Germination
11.
BMC Oral Health ; 24(1): 1063, 2024 Sep 11.
Article in English | MEDLINE | ID: mdl-39261810

ABSTRACT

BACKGROUND: Streptococcus mutans is studied for its acidogenic and aciduric characteristics, notably its biofilm formation in the presence of sucrose, toward its role in the caries process. Variations in both genotype and phenotype have been reported among clinical isolates of S. mutans. This study aimed to examine genotypic and phenotypic characteristics of S. mutans obtained from Thai children with varying caries statuses. METHODS: We determined the presence of S. mutans and caries status in 395 children aged 3-4 years. From 325 children carrying S. mutans, we selected 90 with different caries statuses-caries-free (CF; n = 30), low severity of caries (LC; n = 30), or high severity of caries (HC; n = 30). Three isolates of S. mutans were taken from each child, thus, a total of 270 isolates were obtained. Multilocus sequence typing (MLST) was used to genotype the isolates and assess their clonal relationships. The properties, including biofilm formation, collagen binding, and acid production and tolerance were also evaluated. RESULTS: Children with carious lesions showed a higher detection rate and number of S. mutans in saliva than those without caries. S. mutans from individuals with HC status showed the lowest biofilm formation ability, while this group had the highest detection rate of collagen-binding isolates. There was no difference in acid production or tolerance by caries status. Genotyping by MLST did not reveal any clone of S. mutans specific to CF status. This result remained even when we included MLST data from the open-access PubMLST database. MLST did identify clones containing only strains from caries-affected hosts, but tests of their phenotypic properties did not reveal any differences between S. mutans from these clones and clones that were from both caries-free and caries-affected children. CONCLUSIONS: The clonal relationships of S. mutans indicated by MLST were not associated with the status of dental caries in the host.


Subject(s)
Biofilms , Dental Caries , Genotype , Multilocus Sequence Typing , Phenotype , Saliva , Streptococcus mutans , Humans , Streptococcus mutans/genetics , Streptococcus mutans/isolation & purification , Dental Caries/microbiology , Child, Preschool , Thailand , Biofilms/growth & development , Saliva/microbiology , Female , Male , DMF Index , Southeast Asian People
12.
J Conserv Dent Endod ; 27(7): 750-754, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39262597

ABSTRACT

Aim: The aim of the study was to assess and evaluate the antimicrobial effectiveness of chitosan nanoparticles (CSNPs) with calcium hydroxide in the elimination of Enterococcus faecalis. Materials and Methods: Using the broth microdilution method, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of calcium hydroxide and CSNPs were measured. The antibiofilm effect of calcium hydroxide and CSNPs against E. faecalis biofilm was qualitatively analyzed using a crystal violet assay. A 7-day-old biofilms of E. faecalis grown on dentine discs were assigned to the following three groups (n = 11 dentine discs), normal saline (group I), calcium hydroxide (group II), and CSNPs (group III). Quantification of live and dead cells using confocal microscopy was done to evaluate the antibiofilm efficacy of the medicaments included in the study. Results: MIC of calcium hydroxide and CSNPs against E. faecalis was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. MBC of calcium hydroxide and CSNPs was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. Using Crystal Violet (CV) assay, calcium hydroxide and CSNPs showed biofilm inhibition at concentrations of 2.5 mg/mL and 0.625 mg/mL, respectively. Confocal laser scanning microscopy analysis found that both calcium hydroxide and CSNPs showed a significant decrease in viable cells at their MBC values compared to the control group's normal saline. CSNPs showed a significantly lower percentage of live cells than calcium hydroxide (P < 0.05). Conclusion: The study results reveal that the antimicrobial efficacy of CSNPs is better than calcium hydroxide and normal saline against E. faecalis biofilm.

13.
Heliyon ; 10(17): e36243, 2024 Sep 15.
Article in English | MEDLINE | ID: mdl-39263065

ABSTRACT

Phages are ubiquitous in freshwater, seawater, soil, the human body, and sewage water. They are potent biopharmaceuticals against antimicrobial-resistant bacteria and offer a promising alternative for treating infectious diseases. Also, combining phages with antibiotics enhances the antibiotics' efficacy. This study focused on two Pseudomonas aeruginosa phages isolated from lake and sewage water samples and one of them selected for further investigation. Isolated phages PA-56 and PA-18 infected 92 % and 86 % of the tested 25 clinical Pseudomonas aeruginosa strains, respectively. PA-56 with strong activity was chosen for detailed characterization, antimicrobial studies, and genome analysis. Combining PA-56 with ciprofloxacin or meropenem demonstrated phage-antibiotic synergism and increased antibiofilm efficacy. Genome analysis revealed a GC ratio of 54 % and a genome size of 42.761 bp, with no virulence or antibiotic resistance genes. Notably, PA-56 harboured the toxin-antitoxin protein, MazG. Overall, this study suggests that PA-56 holds promise for future applications in industry or medicine.

14.
Article in English | MEDLINE | ID: mdl-39264555

ABSTRACT

Biofilms may contain pathogenic and spoilage bacteria and can become a recurring problem in the dairy sector, with a negative impact on product quality and consumer health. Peracetic acid (PAA) is one of the disinfectants most frequently used to control biofilm formation and persistence. Though effective, it cannot be used at high concentrations due to its corrosive effect on certain materials and because of toxicity concerns. The aim of this study was to test the possibility of PAA remaining bactericidal at lower concentrations by using it in conjunction with reuterin (3-hydroxypropionaldehyde). We evaluated the efficacy of PAA in pure form or as BioDestroy®, a PAA-based commercial disinfectant, on three-species biofilms formed by dairy-derived bacteria, namely Pseudomonas azotoformans PFlA1, Serratia liquefaciens Sl-LJJ01, and Bacillus licheniformis Bl-LJJ01. Minimum inhibitory concentrations of the three agents were determined for each bacterial species and the fractional inhibitory concentrations were then calculated using the checkerboard assay. The minimal biofilm eradication concentration (MBEC) of each antibacterial combination was then calculated against mixed-species biofilm. PAA, BioDestroy®, and reuterin showed antibiofilm activity against all bacteria within the mixed biofilm at respectively 760 ppm, 450 ppm, and 95.6 mM. The MBEC was lowered significantly to 456 ppm, 337.5 ppm, and 71.7 mM, when exposed to reuterin for 16 h followed by contact with disinfectant. Combining reuterin with chemical disinfection shows promise in controlling biofilm on food contact surfaces, especially for harsh or extended treatments. Furthermore, systems with reuterin encapsulation and nanotechnologies could be developed for sustainable antimicrobial efficacy without manufacturing disruptions.

15.
Bull Exp Biol Med ; 2024 Sep 12.
Article in English | MEDLINE | ID: mdl-39264564

ABSTRACT

The species identity of the studied lactobacillus strains was confirmed by matrix-activated laser desorption/ionization with time-of-flight ion separation (MALDI-TOF mass spectrometry). Lactobacillus strains differed in the dynamics of lactic acid accumulation and changes in the pH of the culture medium. The culture medium affected adhesion ability of lactobacilli. The ability to adhere does not affect the formation of biofilms by lactobacillus strains except for the L. acidophilus La5 strain, which has low adhesion ability and fewer microbial cells detected after mechanical destruction of the biofilm. The metabiotics of the lactobacillus culture medium have an antagonistic effect on conditionally pathogenic microorganisms. Adhesion, biofilm formation, and antagonistic activity of probiotic lactobacillus strains are strain-specific properties.

16.
Biochim Biophys Acta Proteins Proteom ; 1873(1): 141046, 2024 Sep 04.
Article in English | MEDLINE | ID: mdl-39241938

ABSTRACT

BACKGROUND: Serratiopeptidase, a serine protease traditionally used as an oral anti-inflammatory drug has been found to show antibiofilm action. Structurally, it comprises of two distinct domains; viz-the N-terminal catalytic domain (Ncat) and a C-terminal RTX (Repeat-In-Toxin) domain (Crtx). Understanding the antibiofilm action of the serratiopeptidase molecule, as well as the antibiofilm action of each of its two domains, was the objective of this study. RESULTS: Separate clones to express the complete recombinant serratiopeptidase protein and its variant containing a mutation in the catalytic site, the N-terminal catalytic domain and its mutant, and the C-terminal Repeat-In-Toxin domain were prepared, and the proteins were purified. The impact of these proteins on pre-existing biofilms, as well as their effect upon addition of these proteins during biofilm formation was investigated. CONCLUSIONS: In our investigation, we have been able to analyze the antibiofilm action of serratiopeptidase in detail. Obtained results conclude that while N-terminally located proteolytic domain of serratiopeptidase conventionally acts against biofilms by hydrolytic activity, the C-terminal domain regulates or prevents biofilm formation by yet unknown mechanism in addition to its known function as an C-terminal located calcium modulated internal chaperone ensuring the proper folding and secretion of the molecule. The study's findings give new evidence that the Crtx domain plays a significant role in antibiofilm action. The proteolytic Ncat domain breaks down pre-formed biofilms. The C-terminal domain, on the other hand, acts as an inhibitor of biofilm formation by regulating or preventing biofilm development.

17.
BMC Res Notes ; 17(1): 252, 2024 Sep 09.
Article in English | MEDLINE | ID: mdl-39252055

ABSTRACT

OBJECTIVE: The purpose of this study is a new update on the resistance profile, Macrolide-Lincosamide-Streptogramin B resistance mechanisms and biofilm formation in the Staphylococcus aureus isolated from health care workers (HCWs) nasal carriage at a children's teaching hospital in Babol (Northern Iran). RESULTS: A total of 143 non-repetitive nasal swab samples were collected from volunteers, where 53.8% (n; 77/143) were HCWs, 33.6% (n; 48/143) medical students, and 12.6% (n; 18/143) resident students. The prevalence of nasal carriers of S. aureus was 22.4% (n; 32/143), among them, 40.6% (n; 13/32) were identified as methicillin-resistant Staphylococcus aureus (MRSA( carriers. Antimicrobial susceptibility testing showed that erythromycin (68.8%, n; 22/32) and ciprofloxacin (15.6%, n; 5/32) had the highest and lowest resistance rate, respectively. The frequency of resistance genes in the strains was as follows; ermC (n; 17/32, 53.1%), ermA (n; 11/32, 34.4%), ermB (n; 6/32, 18.7%), ereA (n; 3/32, 9.4%). Moreover, 50.0% (n; 16/32), 28.1% (n; 9/32) and 21.8% (n; 7/32) of isolates were strongly, weakly and moderately biofilm producer, respectively. Macrolides-lincosamides-streptogramins B (MLSB) antibiotic resistance among S. aureus isolates from HCWs nasal carriage have found significant prevalence rates throughout the globe. It is crucial to remember that the development of biofilms and MLS B antibiotic resistance are both dynamic processes.


Subject(s)
Anti-Bacterial Agents , Biofilms , Carrier State , Clindamycin , Health Personnel , Methicillin-Resistant Staphylococcus aureus , Microbial Sensitivity Tests , Staphylococcal Infections , Staphylococcus aureus , Humans , Biofilms/drug effects , Biofilms/growth & development , Clindamycin/pharmacology , Anti-Bacterial Agents/pharmacology , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/physiology , Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/physiology , Staphylococcal Infections/microbiology , Staphylococcal Infections/epidemiology , Carrier State/microbiology , Iran , Male , Adult , Female , Erythromycin/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Drug Resistance, Bacterial/genetics
18.
J Extracell Vesicles ; 13(9): e12507, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39252550

ABSTRACT

Vibrio cholerae, a facultative human pathogen and causative agent of the severe diarrheal disease cholera, transits between the human intestinal tract and aquatic reservoirs. Like other bacterial species, V. cholerae continuously releases bacterial extracellular vesicles (BEVs) from its surface, which have been recently characterised for their role during in vivo colonisation. However, between epidemic outbreaks, V. cholerae persists in the biofilm mode for extended periods in aquatic reservoirs, which enhances environmental fitness and host transition. In this study, we investigated the effect of V. cholerae BEVs on biofilm formation, a critical feature for ex vivo survival. In contrast to BEVs from planktonic cultures, our results show that physiological concentrations of BEVs from dynamic biofilm cultures facilitate V. cholerae biofilm formation, which could be linked to a proteinaceous factor. Comparative proteomic analyses of planktonic- and biofilm-derived BEVs identified a previously uncharacterised outer membrane protein as an abundant component of dynamic biofilm-derived BEVs, which was found to be responsible for the BEV-dependent enhancement of biofilm production. Consequently, this protein was named outer membrane-associated biofilm facilitating protein A (ObfA). Comprehensive molecular studies unravelled ObfA as a negative modulator of HapR activity. HapR is a key transcriptional regulator of the V. cholerae quorum sensing (QS) cascade acting as a potent repressor of biofilm formation and virulence. Consistently, obfA mutants not only exhibited reduced biofilm production but also reduced colonisation fitness. Surprisingly, our results demonstrate that ObfA does not affect HapR through the canonical QS system but via the Csr-cascade altering the expression of the small regulatory RNAs CsrC and CsrD. In summary, this study elucidates a novel intraspecies BEV-based communication in V. cholerae that influences biofilm formation and colonisation fitness via a new regulatory pathway involving HapR, Csr-cascade and the BEV-associated protein ObfA.


Subject(s)
Bacterial Proteins , Biofilms , Extracellular Vesicles , Quorum Sensing , Vibrio cholerae , Extracellular Vesicles/metabolism , Biofilms/growth & development , Vibrio cholerae/metabolism , Vibrio cholerae/physiology , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Gene Expression Regulation, Bacterial , Humans , Proteomics/methods , Cholera/microbiology , Cholera/metabolism , Bacterial Outer Membrane Proteins/metabolism , Bacterial Outer Membrane Proteins/genetics
19.
Food Microbiol ; 124: 104616, 2024 Dec.
Article in English | MEDLINE | ID: mdl-39244368

ABSTRACT

Based on the previous research results that the addition of sucrose in the medium improved the biofilm formation of Tetragenococcus halophilus, the influence of sucrose on biofilm formation was explored. Moreover, the influence of exogenous expression of related genes sacA and galE from T. halophilus on the biofilm formation of L. lactis NZ9000 was investigated. The results showed that the addition of sucrose in the medium improved the biofilm formation, the resistance of biofilm cells to freeze-drying stress, and the contents of exopolysaccharides (EPS) and eDNA in the T. halophilus biofilms. Meanwhile, the addition of sucrose in the medium changed the monosaccharide composition of EPS and increased the proportion of glucose and galactose in the monosaccharide composition. Under 2.5% (m/v) salt stress condition, the expression of gene sacA promoted the biofilm formation and the EPS production of L. lactis NZ9000 with the sucrose addition in the medium and changed the EPS monosaccharide composition. The expression of gene galE up-regulated the proportion of rhamnose, galactose, and arabinose in the monosaccharide composition of EPS, and down-regulated the proportion of glucose and mannose. This study will provide a theoretical basis for regulating the biofilm formation of T. halophilus, and provide a reference for the subsequent research on lactic acid bacteria biofilms.


Subject(s)
Biofilms , Sucrose , Biofilms/growth & development , Sucrose/metabolism , Polysaccharides, Bacterial/metabolism , Enterococcaceae/genetics , Enterococcaceae/metabolism , Enterococcaceae/physiology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Monosaccharides/metabolism , Gene Expression Regulation, Bacterial , Freeze Drying
20.
Eur Urol Focus ; 2024 Sep 06.
Article in English | MEDLINE | ID: mdl-39244510

ABSTRACT

Bacteria develop biofilms for protection and persistent colonization. Biofilms of pathogenic bacteria can lead to serious medical problems. Bacterial biofilms on catheters used in the treatment of urinary tract diseases represent a major challenge for antibiotic therapy. Several attempts to eradicate biofilms using classical antibiotics and various alternatives, including antibiotic treatment of surfaces, surfaces that release silver ions, and surfaces with anti-adhesive properties, have not shown clinical efficacy in biofilm prevention or removal. Pseudomonas aeruginosa is one of the most problematic biofilm-forming uropathogens and accounts for approximately 10% of urinary tract infections. Novel glycomimetics that inhibit bacterial lectins have shown promising results in the prevention of P. aeruginosa biofilms and in interference with bacterial virulence. This mini-review summarizes the status of glycomimetic development and provides a perspective on their use in clinical practice. PATIENT SUMMARY: For patients with recurrent urinary tract infections and patients needing long-term catheter use to manage urinary problems, biofilms formed by bacteria can be a problem and are difficult to treat. New compounds that mimic carbohydrates, called glycomimetics, have shown promise in inhibiting these bacteria and the biofilms they form. More research on these compounds is needed before they can be used to treat patients.

SELECTION OF CITATIONS
SEARCH DETAIL