Displaying publications 181 - 200 of 326 in total

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  1. Fulltext Transcriptional profiling of coaggregation interactions between Streptococcus gordonii and Veillonella parvula by Dual RNA-Seq
    Mutha NVR, Mohammed WK, Krasnogor N, Tan GYA, Wee WY, Li Y, et al.
    Sci Rep, 2019 05 21;9(1):7664.
    PMID: 31113978 DOI: 10.1038/s41598-019-43979-w
    Many oral bacteria form macroscopic clumps known as coaggregates when mixed with a different species. It is thought that these cell-cell interactions are critical for the formation of mixed-species biofilms such as dental plaque. Here, we assessed the impact of coaggregation between two key initial colonizers of dental plaque, Streptococcus gordonii and Veillonella parvula, on gene expression in each partner. These species were shown to coaggregate in buffer or human saliva. To monitor gene regulation, coaggregates were formed in human saliva and, after 30 minutes, whole-transcriptomes were extracted for sequencing and Dual RNA-Seq analysis. In total, 272 genes were regulated in V. parvula, including 39 genes in oxidoreductase processes. In S. gordonii, there was a high degree of inter-sample variation. Nevertheless, 69 genes were identified as potentially regulated by coaggregation, including two phosphotransferase system transporters and several other genes involved in carbohydrate metabolism. Overall, these data indicate that responses of V. parvula to coaggregation with S. gordonii are dominated by oxidative stress-related processes, whereas S. gordonii responses are more focussed on carbohydrate metabolism. We hypothesize that these responses may reflect changes in the local microenvironment in biofilms when S. gordonii or V. parvula immigrate into the system.
    Matched MeSH terms: Biofilms
  2. Influence of benzyltriethylammonium chloride on biocorrosion activity of consortium bacteria from tropical crude oil
    Mohd Nazri Idris, Abdul Razak Daud, Nur Akma Mahat, Mohd Hafizuddin Ab Ghani, Norinsan Kamil Othman, Fathul Karim Sahrani
    Sains Malaysiana, 2015;44:1593-1598.
    The performance of pipeline system used in petroleum industry is crucially declined by natural microbial activities and
    demanding extra operational cost. Requirement on high capability of functional substances is attracting worldwide
    research interest. The aim of this paper was to study the effectiveness of benzyltriethylammonium chloride (BTC) on
    reducing the activity of a consortium bacteria consisting of sulfate-reducing bacteria (C-SRB). C-SRB was isolated from
    tropical crude oil and enumeration of this consortium was measured by viable cell count technique. The effectiveness of
    BTC was calculated from potentiodynamic polarization method and biofilm analysis was performed by scanning electron
    microscope. The viable cell count technique indicated that the maximum growth of C-SRB was approximately 160 trillion
    CFU/mL at 7 days incubation period. BTC was capable of reducing biocorrosion activity due to adsorption process and
    mitigating SRB species. Biofilm analysis has proven that C-SRB activity is minimized due to less presence of bacterial
    growth, extracellular polymeric substances and corrosion product. In conclusion, BTC is capable to inhibit C-SRB activity
    on biocorrosion of carbon steel pipeline.
    Matched MeSH terms: Biofilms
  3. A comparison of different disinfectants on the microbiological quality of water from the Dental Unit Waterlines of a Military Hospital
    Mei Siang Ma, Zalini Yunus, Zukri Ahmad, Farizah Abdul Fatah
    Sains Malaysiana, 2015;44:187-192.
    Water from the dental unit waterlines (DUWLs) is known to contaminate with microbial from the biofilm that formed in the tubing system. The water quality from DUWLs is important to patients and dental health care professionals as they could be infected either directly from the contaminated water or aerosol that is generated during dental procedures. Suppliers claimed that dental units supplied to the hospital can only use a specific disinfectant which is uneconomic compared with the others. The aims of this study were to evaluate and compare the efficacy of different disinfectant on the water quality of DUWLs. Four disinfectants (Calbenium, A-dec ICX tablet, Dentel 5, Metassys) and distil water were evaluated. 350 mL water sample was collected separately, from the outlet of high-speed handpiece, scaler, 3-ways syringe and cup filler into a sterile thiosulfate bag on the 1st, 2nd, 4th, 8th, 12th and 24th weeks of the study. The samples were tested on the following day for total viable count (TVC). There is significant difference in the efficacies of the different disinfectants. Only one disinfectant consistently produces water quality within the recommended level of American Dental Association (ADA). Within the limitation of this study, it was found that there is alternative disinfectant that can reduce the TVC to the level recommended by ADA. However, the water qualities produced with these disinfectants were not consistent although they did not cause any technical problem to the dental units during the period of study.
    Matched MeSH terms: Biofilms
  4. Fulltext Allium-sativum and bakuchiol combination: A natural alternative to Chlorhexidine for oral infections?
    Fahim A, Himratul-Aznita WH, Abdul-Rahman PS
    Pak J Med Sci, 2020 2 18;36(2):271-275.
    PMID: 32063973 DOI: 10.12669/pjms.36.2.1457
    Objective: Chlorhexidine mouthrinses are considered a gold standard as an adjunct treatment of oral infections. However, owing to its toxicity, discoloration of tooth surface and the emerging prevalence of drug-resistant species, attention is being given to exploring natural alternatives to the drug.

    Methods: The experiment was carried out in Azra Naheed Center for Research and Development (ANCRD), Superior University, Lahore, Pakistan from September 2018 till May 2019. Biofilms and planktonic cells of C. albicans alone and in combination with streptococci were subjected to chlorhexidine, allium sativum and bakuchiol individually and to allium-bakuchiol combination. Kirby-Bauer test, antifungal susceptibility testing, CFU count and drug synergy assessment was done on planktonic cells. Dynamic biofilms were formed to mimic conditions similar to oral cavity and CFU was determined.

    Results: MIC of all three agents was higher against mixed species when compared to single species planktonic cells and biofilm. Allium sativum and bakuchiol demonstrated synergistic effects. The decrease in CFU count and minimum biofilm reduction to salivary pellicle caused by allium sativum-bakuchiol was comparable to that of chlorhexidine.

    Conclusion: Thus, allium sativum-bakuchiol combination demonstrated antimicrobial effects similar to chlorhexidine against planktonic cells and dynamic biofilm. It could serve as a possible natural, economical alternative to chlorhexidine mouthrinses usually recommended in dental clinics. However, in vivo studies are required to determine the correct dosage of these agents.

    Matched MeSH terms: Biofilms
  5. The Travelling Particles: Investigating microplastics as possible transport vectors for multidrug resistant E. coli in the Weser estuary (Germany)
    Song J, Jongmans-Hochschulz E, Mauder N, Imirzalioglu C, Wichels A, Gerdts G
    Sci Total Environ, 2020 Jun 10;720:137603.
    PMID: 32143053 DOI: 10.1016/j.scitotenv.2020.137603
    The prevalence of multidrug-resistant Gram-negative bacteria in aquatic environments has been a long withstanding health concern, namely extended-spectrum beta-lactamase (ESBL) producing Escherichia coli. Given increasing reports on microplastic (MP) pollution in these environments, it has become crucial to better understand the role of MP particles as transport vectors for such multidrug-resistant bacteria. In this study, an incubation experiment was designed where particles of both synthetic and natural material (HDPE, tyre wear, and wood) were sequentially incubated at multiple sites along a salinity gradient from the Lower Weser estuary (Germany) to the offshore island Helgoland (German Bight, North Sea). Following each incubation period, particle biofilms and water samples were assessed for ESBL-producing E. coli, first by the enrichment and detection of E. coli using Fluorocult® LMX Broth followed by cultivation on CHROMAgar™ ESBL media to select for ESBL-producers. Results showed that general E. coli populations were present on the surfaces of wood particles across all sites but none were found to produce ESBLs. Additionally, neither HDPE nor tyre wear particles were found to harbour any E. coli. Conversely, ESBL-producing E. coli were present in surrounding waters from all sites, 64% of which conferred resistances against up to 3 other antibiotic groups, additional to the beta-lactam resistances intrinsic to ESBL-producers. This study provides a first look into the potential of MP to harbour and transport multidrug-resistant E. coli across different environments and the approach serves as an important precursor to further studies on other potentially harmful MP-colonizing species.
    Matched MeSH terms: Biofilms
  6. Fulltext The efficacy of honey-cinnamon commixture in diabetic wound healing. [Abstract]
    Azib FN, Lee CH, Mohd Yusof NM, Yusuf N, Mohd Fuad NF, Saharuddin NS, et al.
    Malaysian Journal of Medicine and Health Sciences, 2020;16(105):23-0.
    MyJurnal
    1st UMS INTERNATIONAL NURSING CONFERENCE IN CONJUNCTION WITH 11TH INTERNATIONAL NURSING STUDENTS’ FORUM
    A view into the future of nursing: Nursing Transformation towards IR-4.0, Held at the Faculty of Medicine and Health Sciences,, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia, On 6-8th March 2020
    Introduction: Delayed wound healing and a hefty cost of treatment poses a burden to those undergoing treatment for Diabetic wound care. An alternative wound product to speed up wound healing may address this problem. Honey has been recognized around the world for its efficacy as treating wounds, eczema, and inflammation while cinnamon has a variety of biological functions including anti-diabetic, anti-microbial, and anti-inflammatory. As both cinnamon and honey possess different properties in wound healing, it is hypothesized that combining both products can accelerate wound healing. This study is to compare the efficacy of pure honey, pure cinnamon and honey-cinnamon commixture in diabetic wound healing.
    Methods: Three volunteers were selected from Kitamura clinic, Pontianak, Indonesia participated in this study. Each of them was given a different wound product which were pure honey (subject 1), pure cinnamon extract (subject 2), and honey-cinnamon commixture (subject 3). The wound bed percentage, size, and characteristics were recorded and compared. Results: Usage of pure cinnamon was discontinued during the second visit due to its drying effect. Subjects 1 and 3 both presented with an increase in granulation and reduction in sloughing of cells and biofilm. However, subject 3 showed faster wound contraction and reduction in maceration as compared to subject 1.
    Conclusion: Pure cinnamon extract should not be used as a standalone wound product due to its drying properties. However, topical co-administration of honey and Cinnamon cassia extract has a synergistic interaction effect, improves wound healing in diabetic individuals and is recommended as a new topical herbal drug production for treating of the diabetic wound. Further studies on the therapeutic concentration of honey-cinnamon commixture should be conducted.
    Matched MeSH terms: Biofilms
  7. Development of biofilm-targeted antimicrobial wound dressing for the treatment of chronic wound infections
    Ng SF, Leow HL
    Drug Dev Ind Pharm, 2015;41(11):1902-9.
    PMID: 25758412 DOI: 10.3109/03639045.2015.1019888
    It has been established that microbial biofilms are largely responsible for the recalcitrance of many wound infections to conventional antibiotics. It was proposed that the efficacy of antibiotics could be optimized via the inhibition of bacterial biofilm growth in wounds. The combination of antibiofilm agent and antibiotics into a wound dressing may be a plausible strategy in wound infection management. Xylitol is an antibiofilm agent that has been shown to inhibit the biofilm formation. The purpose of this study was to develop an alginate film containing xylitol and gentamicin for the treatment of wound infection. Three films, i.e. blank alginate film (SA), alginate film with xylitol (F5) and alginate film with xylitol and gentamicin (AG), were prepared. The films were studied for their physical properties, swelling ratio, moisture absorption, moisture vapor transmission rate (MVTR), mechanical and rheology properties, drug content uniformity as well as in vitro drug release properties. Antimicrobial and antibiofilm in vitro studies on Staphylococcus aureus and Pseudomonas aeruginosa were also performed. The results showed that AG demonstrates superior mechanical properties, rheological properties and a higher MVTR compared with SA and F5. The drug flux of AG was higher than that of commercial gentamicin cream. Furthermore, antimicrobial studies showed that AG is effective against both S. aureus and P. aeruginosa, and the antibiofilm assays demonstrated that the combination was effective against biofilm bacteria. In summary, alginate films containing xylitol and gentamicin may potentially be used as new dressings for the treatment of wound infection.
    Matched MeSH terms: Biofilms
  8. Fulltext Biosynthesis of Gold Nanoparticles and Its Effect against Pseudomonas aeruginosa
    Ali SG, Jalal M, Ahmad H, Umar K, Ahmad A, Alshammari MB, et al.
    Molecules, 2022 Dec 08;27(24).
    PMID: 36557818 DOI: 10.3390/molecules27248685
    Antimicrobial resistance has posed a serious health concern worldwide, which is mainly due to the excessive use of antibiotics. In this study, gold nanoparticles synthesized from the plant Tinospora cordifolia were used against multidrug-resistant Pseudomonas aeruginosa. The active components involved in the reduction and stabilization of gold nanoparticles were revealed by gas chromatography-mass spectrophotometry(GC-MS) of the stem extract of Tinospora cordifolia. Gold nanoparticles (TG-AuNPs) were effective against P. aeruginosa at different concentrations (50,100, and 150 µg/mL). TG-AuNPs effectively reduced the pyocyanin level by 63.1% in PAO1 and by 68.7% in clinical isolates at 150 µg/mL; similarly, swarming and swimming motilities decreased by 53.1% and 53.8% for PAO1 and 66.6% and 52.8% in clinical isolates, respectively. Biofilm production was also reduced, and at a maximum concentration of 150 µg/mL of TG-AuNPs a 59.09% reduction inPAO1 and 64.7% reduction in clinical isolates were observed. Lower concentrations of TG-AuNPs (100 and 50 µg/mL) also reduced the pyocyanin, biofilm, swarming, and swimming. Phenotypically, the downregulation of exopolysaccharide secretion from P. aeruginosa due to TG-AuNPs was observed on Congo red agar plates.
    Matched MeSH terms: Biofilms
  9. Lactoferrin modulates the biofilm formation and bap gene expression of methicillin-resistant Staphylococcus epidermidis
    Khanum R, Chung PY, Clarke SC, Chin BY
    Can J Microbiol, 2023 Feb 01;69(2):117-122.
    PMID: 36265186 DOI: 10.1139/cjm-2022-0135
    Lactoferrin is an innate glycoprotein with broad antibacterial and antibiofilm properties. The autonomous antibiofilm activity of lactoferrin against Gram-positive bacteria is postulated to involve the cell wall and biofilm components. Thus, the prevention of biomass formation and eradication of preformed biofilms by lactoferrin was investigated using a methicillin-resistant Staphylococcus epidermidis (MRSE) strain. Additionally, the ability of lactoferrin to modulate the expression of the biofilm-associated protein gene (bap) was studied. The bap gene regulates the production of biofilm-associated proteins responsible for bacterial adhesion and aggregation. In the in vitro biofilm assays, lactoferrin prevented biofilm formation and eradicated established biofilms for up to 24 and 72 h, respectively. Extensive eradication of MRSE biofilm biomass was accompanied by the significant upregulation of bap gene expression. These data suggest the interaction of lactoferrin with the biofilm components and cell wall of MRSE, including the biofilm-associated protein.
    Matched MeSH terms: Biofilms
  10. Pseudomonas aeruginosa behaviour in polymicrobial communities: The competitive and cooperative interactions conducting to the exacerbation of infections
    Al-Wrafy FA, Alariqi R, Noman EA, Al-Gheethi AA, Mutahar M
    Microbiol Res, 2023 Mar;268:127298.
    PMID: 36610273 DOI: 10.1016/j.micres.2022.127298
    Pseudomonas aeruginosa is mostly associated with persistent infections and antibiotic resistance as a result of several factors, biofilms one of them. Microorganisms within the polymicrobial biofilm (PMB) reveal various transcriptional profiles and affect each other which might influence their pathogenicity and antibiotic tolerance and subsequent worsening of the biofilm infection. P. aeruginosa within PMB exhibits various behaviours toward other microorganisms, which may enhance or repress the virulence of these microbes. Microbial neighbours, in turn, may affect P. aeruginosa's virulence either positively or negatively. Such interactions among microorganisms lead to emerging persistent and antibiotic-resistant infections. This review highlights the relationship between P. aeruginosa and its microbial neighbours within the PMB in an attempt to better understand the mechanisms of polymicrobial interaction and the correlation between increased exacerbations of infection and the P. aeruginosa-microbe interaction. Researching in the literature that was carried out in vitro either in co-cultures or in the models to simulate the environment at the site of infection suggested that the interplay between P. aeruginosa and other microorganisms is one main reason for the worsening of the infection and which in turn requires a treatment approach different from that followed with P. aeruginosa mono-infection.
    Matched MeSH terms: Biofilms
  11. Antimicrobial activities of graphene oxide against biofilm and intracellular Staphylococcus aureus isolated from bovine mastitis
    Saeed SI, Vivian L, Zalati CWSCW, Sani NIM, Aklilu E, Mohamad M, et al.
    BMC Vet Res, 2023 Jan 14;19(1):10.
    PMID: 36641476 DOI: 10.1186/s12917-022-03560-6
    BACKGROUND: S. aureus is one of the causative agents of bovine mastitis. The treatment using conventional antimicrobials has been hampered due to the development of antimicrobial resistance and the ability of the bacteria to form biofilms and localize inside the host cells.

    OBJECTIVES: Here, the efficacy of graphene oxide (GO), a carbon-based nanomaterial, was tested against the biofilms and intracellular S. aureus invitro. Following that, the mechanism for the intracellular antimicrobial activities and GO toxicities was elucidated.

    METHODS: GO antibiofilm properties were evaluated based on the disruption of biofilm structure, and the intracellular antimicrobial activities were determined by the survival of S. aureus in infected bovine mammary cells following GO exposure. The mechanism for GO intracellular antimicrobial activities was investigated using endocytosis inhibitors. GO toxicity towards the host cells was assessed using a resazurin assay.

    RESULTS: At 100 ug/mL, GO reduced between 30 and 70% of S. aureus biofilm mass, suggesting GO's ability to disrupt the biofilm structure. At 200 ug/mL, GO killed almost 80% of intracellular S. aureus, and the antimicrobial activities were inhibited when cells were pre-treated with cytochalasin D, suggesting GO intracellular antimicrobial activities were dependent on the actin-polymerization of the cell membrane. At

    Matched MeSH terms: Biofilms
  12. Flagellar motility mediates biofilm formation in Aeromonas dhakensis
    Lau TV, Puah SM, Tan JMA, Merino S, Puthucheary SD, Chua KH
    Microb Pathog, 2023 Apr;177:106059.
    PMID: 36878334 DOI: 10.1016/j.micpath.2023.106059
    Aeromonas dhakensis possesses dual flagellar systems for motility under different environments. Flagella-mediated motility is necessary for biofilm formation through an initial attachment of bacteria to the surface, but this has not been elucidated in A. dhakensis. This study investigates the role of polar (flaH, maf1) and lateral (lafB, lafK and lafS) flagellar genes in the biofilm formation of a clinical A. dhakensis strain WT187 isolated from burn wound infection. Five deletion mutants and corresponding complemented strains were constructed using pDM4 and pBAD33 vectors, respectively, and analyzed for motility and biofilm formation using crystal violet staining and real-time impedance-based assays. All mutants were significantly reduced in swimming (p 
    Matched MeSH terms: Biofilms
  13. Fulltext Microbiota organization is a distinct feature of proximal colorectal cancers
    Dejea CM, Wick EC, Hechenbleikner EM, White JR, Mark Welch JL, Rossetti BJ, et al.
    Proc Natl Acad Sci U S A, 2014 Dec 23;111(51):18321-6.
    PMID: 25489084 DOI: 10.1073/pnas.1406199111
    Environmental factors clearly affect colorectal cancer (CRC) incidence, but the mechanisms through which these factors function are unknown. One prime candidate is an altered colonic microbiota. Here we show that the mucosal microbiota organization is a critical factor associated with a subset of CRC. We identified invasive polymicrobial bacterial biofilms (bacterial aggregates), structures previously associated with nonmalignant intestinal pathology, nearly universally (89%) on right-sided tumors (13 of 15 CRCs, 4 of 4 adenomas) but on only 12% of left-sided tumors (2 of 15 CRCs, 0 of 2 adenomas). Surprisingly, patients with biofilm-positive tumors, whether cancers or adenomas, all had biofilms on their tumor-free mucosa far distant from their tumors. Bacterial biofilms were associated with diminished colonic epithelial cell E-cadherin and enhanced epithelial cell IL-6 and Stat3 activation, as well as increased crypt epithelial cell proliferation in normal colon mucosa. High-throughput sequencing revealed no consistent bacterial genus associated with tumors, regardless of biofilm status. However, principal coordinates analysis revealed that biofilm communities on paired normal mucosa, distant from the tumor itself, cluster with tumor microbiomes as opposed to biofilm-negative normal mucosa bacterial communities also from the tumor host. Colon mucosal biofilm detection may predict increased risk for development of sporadic CRC.
    Matched MeSH terms: Biofilms
  14. The phenotypes and genotypes associated with biofilm formation among methicillin-susceptible Staphylococcus aureus (MSSA) isolates collected from a tertiary hospital in Terengganu, Malaysia
    Jones SU, Chew CH, Yeo CC, Abdullah FH, Othman N, Kee BP, et al.
    Int Microbiol, 2023 Nov;26(4):841-849.
    PMID: 36805382 DOI: 10.1007/s10123-023-00335-3
    Methicillin-susceptible Staphylococcus aureus (MSSA) is an important nosocomial pathogen worldwide. This study aims to investigate the in vitro biofilm-forming ability of clinical MSSA isolated from various sources in the main public tertiary referral hospital in Terengganu, Malaysia and to detect the presence of biofilm-associated and regulatory genes among these isolates. A total of 104 MSSA isolates [pus (n = 75), blood (n = 24), respiratory secretions (n = 2), eye (n = 2), and urine (n = 1)] were investigated for slime production and biofilm formation using Congo red agar and crystal violet microtitre plate, respectively. Fifteen MSSA isolates with varying degrees of biofilm formation were selected for validation via a real-time cell analyser. All isolates were screened for microbial surface components recognising adhesive matrix molecules (MSCRAMM) and accessory gene regulator (agr) using polymerase chain reaction assay. A total of 76.0% (79/104) isolates produced slime layer, while all isolates developed biofilm as follows: 52.8% (55/104) strong biofilm producers, 40.4% (42/104) intermediate biofilm producers, and 6.7% (7/104) weak biofilm producers. A total of 98.1% (102/104) isolates carried at least one of the screened MSCRAMM gene(s) with the eno gene detected at the highest rate (87.5%, 91/104), while the sasG gene was significantly associated with strong biofilm production (p = 0.015). Three agr groups, 1, 2, and 3, were detected among the MSSA isolates with a predominance of agr-3 (32.7%, 34/104). In conclusion, biofilm formation varied greatly among clinical MSSA isolates, and the presence of sasG gene and agr-1 may play important role in initiating MSSA infections via biofilm formation.
    Matched MeSH terms: Biofilms
  15. Fulltext Quaternary ammonium silane (k21) based intracanal medicament triggers biofilm destruction
    Kok ESK, Lim XJ, Chew SX, Ong SF, See LY, Lim SH, et al.
    BMC Oral Health, 2021 03 12;21(1):116.
    PMID: 33711992 DOI: 10.1186/s12903-021-01470-x
    BACKGROUND: Compare antimicrobial efficacy of a quarternary ammonium silane (QAS)/k21 as an intracanal medicament against E. faecalis and C. albicans biofilms formed on root dentin.

    METHODOLOGY: Dentin blocks were sterilized and E. faecalis and C. albicans microbial colonies were counted for colony-forming-units against 2%k21, 2%CHX and Ca(OH)2 medicaments. Biofilm colonies after 7 days on dentin were analysed using confocal laser scanning microscopy with live/dead bacterial viability staining. TEM was done to study dentin collagen matrix. Dentin discs from 3rd day and 7th day well plate was used for Raman spectra and observed under fluorescent-microscope. Docking studies were carried out on MMP-2 S1 binding-domain with k21.

    RESULTS: There was reduction of E. faecalis/C. albicans when k21, chlorhexidine and calcium hydroxide were used with highest percentage in 2%k21 treated specimens. 2%k21 showed dense and regular collagen network with intact cross-banding and decreased Raman intensity for 2%k21 on 3rd day. NaOCl + k21 showed least adherence, whereas saline groups showed highest adherence of E. faecalis and C. albicans to root-canal dentin. Alizarin red staining of hDPSCs revealed calcium deposition in all groups with significant difference seen amongst 2%k21 groups. MMP-2 ligand binding was seen accurately indicating possible target sites for k21 intervention.

    CONCLUSION: 2%k21 can be considered as alternative intracanal medicament.

    Matched MeSH terms: Biofilms
  16. Fulltext Assessment of Antifungal Activity of Bakuchiol on Oral-Associated Candida spp
    Nordin MA, Abdul Razak F, Himratul-Aznita WH
    Evid Based Complement Alternat Med, 2015;2015:918624.
    PMID: 26633986 DOI: 10.1155/2015/918624
    Bakuchiol is an active component of Psoralea glandulosa and Psoralea corylifolia, used in traditional Chinese medicine. The study aimed at investigating the antifungal activity of bakuchiol on planktonic and biofilm forms of orally associated Candida species. The antifungal susceptibility testing was determined by the broth micro dilution technique. Growth kinetics and cell surface hydrophobicity (CSH) of Candida were measured to assess the inhibitory effect of bakuchiol on Candida planktonic cells. Biofilm biomass and cellular metabolic activity were quantitatively estimated by the crystal violet (CV) and the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assays. All Candida strains have been shown to be susceptible to bakuchiol with the MIC ranges from 12.5 to 100 μg/mL. Significant decrease in specific growth rates and viable counts demonstrates the inhibitory effect of bakuchiol on Candida planktonic cells. A brief exposure to bakuchiol also reduced CSH of Candida (P < 0.05), indicating altered surface properties of yeast cells towards hydrophobic interfaces. Biofilm biomass and cell metabolic activity were mostly decreased, except for C. glabrata (P = 0.29). The antifungal properties of bakuchiol on Candida species in this in vitro study may give insights into the application in therapeutic strategy against Candida infections.
    Matched MeSH terms: Biofilms
  17. Fulltext Chemical Composition, Antioxidant, Antibacterial, and Antibiofilm Activities of Backhousia citriodora Essential Oil
    Lim AC, Tang SGH, Zin NM, Maisarah AM, Ariffin IA, Ker PJ, et al.
    Molecules, 2022 Jul 31;27(15).
    PMID: 35956846 DOI: 10.3390/molecules27154895
    The essential oil of Backhousia citriodora, commonly known as lemon myrtle oil, possesses various beneficial properties due to its richness in bioactive compounds. This study aimed to characterize the chemical profile of the essential oil isolated from leaves of Backhousia citriodora (BCEO) and its biological properties, including antioxidant, antibacterial, and antibiofilm activities. Using gas chromatography-mass spectrometry, 21 compounds were identified in BCEO, representing 98.50% of the total oil content. The isomers of citral, geranial (52.13%), and neral (37.65%) were detected as the main constituents. The evaluation of DPPH radical scavenging activity and ferric reducing antioxidant power showed that BCEO exhibited strong antioxidant activity at IC50 of 42.57 μg/mL and EC50 of 20.03 μg/mL, respectively. The antibacterial activity results showed that BCEO exhibited stronger antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) than against Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae). For the agar disk diffusion method, S. epidermidis was the most sensitive to BCEO with an inhibition zone diameter of 50.17 mm, followed by S. aureus (31.13 mm), E. coli (20.33 mm), and K. pneumoniae (12.67 mm). The results from the microdilution method showed that BCEO exhibited the highest activity against S. epidermidis and S. aureus, with the minimal inhibitory concentration (MIC) value of 6.25 μL/mL. BCEO acts as a potent antibiofilm agent with dual actions, inhibiting (85.10% to 96.44%) and eradicating (70.92% to 90.73%) of the biofilms formed by the four tested bacteria strains, compared with streptomycin (biofilm inhibition, 67.65% to 94.29% and biofilm eradication, 49.97% to 89.73%). This study highlights that BCEO can potentially be a natural antioxidant agent, antibacterial agent, and antibiofilm agent that could be applied in the pharmaceutical and food industries. To the best of the authors' knowledge, this is the first report, on the antibiofilm activity of BCEO against four common nosocomial pathogens.
    Matched MeSH terms: Biofilms
  18. Immunotherapies for the prevention and treatment of Staphylococcus aureus infections: updates and challenges
    Chung PY
    Pathog Dis, 2023 Jan 17;81.
    PMID: 37422444 DOI: 10.1093/femspd/ftad016
    Staphylococcus aureus is the leading cause of hospital-acquired infections and can cause a wide range of diseases from mild skin infections to invasive diseases including deep surgical site infections, life-threatening bacteremia, and sepsis. This pathogen remains a challenge to manage due to its ability to rapidly develop resistance to antibiotic treatment and to form biofilms. Despite the current infection control measures which involve mainly antibiotics, the burden of infection remains high. The 'omics' approaches have not led to the discovery of novel antibacterials at a pace sufficient to cope with the emergence of multidrug-resistant and biofilm-forming S. aureus, Hence, new strategies for anti-infective therapies need to be explored urgently. One promising strategy is harnessing the immune response to enhance the protective antimicrobial immunity in the host. This review discusses the potential of monoclonal antibodies and vaccines as alternatives to treat and manage infections caused by planktonic and biofilms of S. aureus.
    Matched MeSH terms: Biofilms
  19. Limosilactobacillus reuteri 29A Cell-Free Supernatant Antibiofilm and Antagonistic Effects in Murine Model of Vulvovaginal Candidiasis
    Boahen A, Chew SY, Neela VK, Than LTL
    Probiotics Antimicrob Proteins, 2023 Dec;15(6):1681-1699.
    PMID: 36881331 DOI: 10.1007/s12602-023-10050-0
    Vaginal dysbiosis advocates burgeoning of devious human vaginal pathobionts like Candida species that possess multiple virulence properties and metabolic flexibility to cause infections. Inevitably, antifungal resistance may emerge due to their innate nature (e.g., biofilm formation), which assists in their virulence as well as the formation of persister cells after dispersal. In consequence, the phenomenon of biofilm involvement in vulvovaginal candidiasis (VVC) and its recurrence is becoming paramount. Lactic acid bacteria and their derivatives have proven to be hostile to Candida species. Here, we throw more light on the potency of the derivatives, i.e., cell-free supernatant (CFS) produced by an indigenously isolated vaginal Lactobacillus strain, Limosilactobacillus reuteri 29A. In the present study, we investigated the antibiofilm and antagonistic effects of L. reuteri 29A CFS, against biofilms of Candida species and in murine model of vulvovaginal candidiasis. In our in vitro biofilm study, the CFS disrupted and inhibited preformed biofilms of C. albicans and C. glabrata. Scanning electron microscopy displayed the destruction of preformed biofilms and impediment of C. albicans morphogenesis by the CFS. Gas chromatography-mass spectrometry analysis showed multiple key compounds that may act singly or synergistically. In vivo, the CFS showed no collateral damage to uninfected mice; the integrity of infected vaginal tissues was restored by the administration of the CFS as seen from the cytological, histopathological, and electron microscopical analyses. The results of this study document the potential use of CFS as an adjuvant or prophylactic option in addressing vaginal fungal infections.
    Matched MeSH terms: Biofilms
  20. Fulltext A Review of Staphylococcal Cassette Chromosome mec (SCCmec) Types in Coagulase-Negative Staphylococci (CoNS) Species
    Saber H, Jasni AS, Jamaluddin TZMT, Ibrahim R
    Malays J Med Sci, 2017 Oct;24(5):7-18.
    PMID: 29386968 MyJurnal DOI: 10.21315/mjms2017.24.5.2
    Coagulase-negative staphylococci (CoNS) are considered low pathogenic organisms. However, they are progressively causing more serious infections with time because they have adapted well to various antibiotics owing to their ability to form biofilms. Few studies have been conducted on CoNS in both, hospital and community-acquired settings, especially in Malaysia. Thus, it is important to study their species and gene distributions. A mobile genetic element, staphylococcal cassette chromosome mec (SCCmec), plays an important role in staphylococci pathogenesis. Among CoNS, SCCmec has been studied less frequently than Staphylococcus aureus (coagulase-positive staphylococci). A recent study (8) conducted in Malaysia successfully detected SCCmec type I to VIII as well as several new combination patterns in CoNS species, particularly Staphylococcus epidermidis. However, data are still limited, and further research is warranted. This paper provides a review on SCCmec types among CoNS species.
    Matched MeSH terms: Biofilms
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