Displaying publications 81 - 100 of 323 in total

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  1. Tang, P.L., Pui, C.F., Wong, W.C., Noorlis, A., Son, R.
    MyJurnal
    This study aimed to determine the biofilm formation ability by Salmonella Typhi on cucumber, mango and guava surface, as well as to determine the relationship between time contact and biofilm formation. Crystal violet assay was performed to quantify the biofilm formation based on the value of optical density at 570 nm of the destaining crystal violet at the specific interval time. The result showed that the attachment of the bacterial cells on the fresh produce surface increased with the contact time. The readings of OD570at time 12 h for cucumber, mango and guava surfaces were 0.824, 0.683 and 0.598, respectively, indicating that the biofilm formation by Salmonella Typhi on different fresh produce surface varied with time. Since the result showed that Salmonella Typhi formed biofilm on fresh produce surfaces, hygienic practice from farm to fork including handling, processing, distribution and storage of the fresh produce should be of concern.
    Matched MeSH terms: Biofilms
  2. Saratale RG, Saratale GD, Pugazhendhi A, Zhen G, Kumar G, Kadier A, et al.
    Chemosphere, 2017 Mar 09;177:176-188.
    PMID: 28288426 DOI: 10.1016/j.chemosphere.2017.02.143
    Microbial electrochemical systems (MESs) are an attracting technology for the disposal of wastewater treatment and simultaneous energy production. In MESs, at the anode microorganisms through the catalytic activity generates electrons that can be converted into electricity or other valuable chemical compounds. Microorganisms those having ability to donate and accept electrons to and from anode and cathode electrodes, respectively are recognized as 'exoelectrogens'. In the MESs, it renders an important function for its performance. In the present mini-review, we have discussed the role of microbiome including pure culture, enriched culture and mixed culture in different BESs application. The effects of operational and biological factors on microbiome development have been discussed. Further discussion about the molecular techniques for the evaluation of microbial community analysis is addressed. In addition different electrochemical techniques for extracellular electron transfer (EET) mechanism of electroactive biofilms have been discussed. This review highlights the importance of microbiome in the development of MESs, effective operational factors for exo-electrogens activities as well their key challenges and future technological aspects are also briefly discussed.
    Matched MeSH terms: Biofilms
  3. Ibrahim, N.Z., Abdullah, M.
    Ann Dent, 2008;15(1):20-26.
    MyJurnal
    This study aim to evaluate antimicrobial efficacy of sodium hypochlorite (NaOCl) and ozonated water against Enterococci faecalis biofilm. The bacterial biofilm was exposed to 2.62%, 1.31% NaOCl and 0.1 ppm ozonated water over a range of time periods. The presence of viable cells was determined by enumeration of colony forming units (CFU). All experiments were repeated four times (n=4). The effectiveness of the agents was compared using nonparametric Kruskal- Wallis test. The result revealed that 2.62% of NaOCl can completely kill E. faecalis biofilm in 15 minutes whereas 1.31 % NaOCl required a longer time to produce such effect. 0.1 ppm ozonated, however, did not exhibit any antimicrobial effect within the period of time tested. From this study, it can be concluded that 0.1 ppm ozonated water was not comparable with 2.62% and 1.31% NaOCl in antimicrobial efficacy against E. faecalis biofilm.
    Matched MeSH terms: Biofilms
  4. Al-Ahmad, Basma Ezzat Mustafa, Muhannad Ali Kashmoola, Nur Aini Zakaria
    MyJurnal
    Recurrent oral ulcer is a chronic inflammatory condition characterized by mucosa
    ulceration, which was believed to have bacterial etiology. Streptococcus mutans is one of the
    bacteria which have been implicated in this case; it is gram-positive bacteria that reside in the
    biofilms on the tooth surfaces. The aim of this study was to evaluate Streptococcus mutans content
    in saliva of recurrent oral ulcer patients and its role as a prognostic factor. (Copied from article).
    Matched MeSH terms: Biofilms
  5. Farah Adiba Yang Abd Talib, Hairul Aini Hamzah, Mohammed Imad Al-Deen Mustafa Mahmoud
    MyJurnal
    Quorum sensing controls a wide spectrum of processes and phenotypic
    behaviours including biofilm formation that helps in the survival and virulence of
    bacteria in hosts. Thus, anti-quorum sensing is suggested to combat bacterial infections.
    This study aimed to evaluate the anti-biofilm forming and anti-quorum sensing activities
    which may contribute to the anti-bacterial effect of ethanol and aqueous extracts of
    Orthosiphon stamineus and Andrographis paniculata leaves and stems. (Copied from article).
    Matched MeSH terms: Biofilms
  6. Venkateshbabu N, Anand S, Abarajithan M, Sheriff SO, Jacob PS, Sonia N
    Open Dent J, 2016;10:214-26.
    PMID: 27386007 DOI: 10.2174/1874210601610010214
    Complete eradication of microbial biofilms and elimination of the smear layer are the key factors during endodontic treatment. Various chemical irrigants have been proposed in the literature for the same. The major setback with these chemical irrigants is that they are not bio-friendly to the dental and peri-radicular tissues. In the recent years, research to use natural products for root canal disinfection has gained importance. The aim of this article is to compile various herbal products that have been used as an irrigants and intracanal medicaments in the field of Endodontics to eradicate the biofilm and remove smear layer.
    Matched MeSH terms: Biofilms
  7. Tan KH, How KY, Tan JY, Yin WF, Chan KG
    Front Microbiol, 2017;8:72.
    PMID: 28197135 DOI: 10.3389/fmicb.2017.00072
    The process of intercellular communication among bacteria, termed quorum sensing (QS), is mediated by small diffusible molecules known as the autoinducers. QS allows the population to react to the change of cell density in unison, in processes such as biofilm formation, plasmid conjugation, virulence, motility and root nodulation. In Gram-negative proteobacteria, N-acyl homoserine lactone (AHL) is the common "language" to coordinate gene expression. This signaling molecule is usually synthesized by LuxI-type proteins. We have previously discovered that a rare bacterium, Cedecea neteri, exhibits AHL-type QS activity. With information generated from genome sequencing, we have identified the luxIR gene pair responsible for AHL-type QS and named it cneIR. In this study, we have cloned and expressed the 636 bp luxI homolog in an Escherichia coli host for further characterization. Our findings show that E. coli harboring cneI produced the same AHL profile as the wild type C. neteri, with the synthesis of AHL known as N-butyryl-homoserine lactone. This 25 kDa LuxI homolog shares high similarity with other AHL synthases from closely related species. This work is the first documentation of molecular cloning and characterization of luxI homolog from C. neteri.
    Matched MeSH terms: Biofilms
  8. Chong PP, Chin VK, Wong WF, Madhavan P, Yong VC, Looi CY
    Genes (Basel), 2018 Nov 07;9(11).
    PMID: 30405082 DOI: 10.3390/genes9110540
    Candida albicans is an opportunistic fungal pathogen, which causes a plethora of superficial, as well as invasive, infections in humans. The ability of this fungus in switching from commensalism to active infection is attributed to its many virulence traits. Biofilm formation is a key process, which allows the fungus to adhere to and proliferate on medically implanted devices as well as host tissue and cause serious life-threatening infections. Biofilms are complex communities of filamentous and yeast cells surrounded by an extracellular matrix that confers an enhanced degree of resistance to antifungal drugs. Moreover, the extensive plasticity of the C. albicans genome has given this versatile fungus the added advantage of microevolution and adaptation to thrive within the unique environmental niches within the host. To combat these challenges in dealing with C. albicans infections, it is imperative that we target specifically the molecular pathways involved in biofilm formation as well as drug resistance. With the advent of the -omics era and whole genome sequencing platforms, novel pathways and genes involved in the pathogenesis of the fungus have been unraveled. Researchers have used a myriad of strategies including transcriptome analysis for C. albicans cells grown in different environments, whole genome sequencing of different strains, functional genomics approaches to identify critical regulatory genes, as well as comparative genomics analysis between C. albicans and its closely related, much less virulent relative, C. dubliniensis, in the quest to increase our understanding of the mechanisms underlying the success of C. albicans as a major fungal pathogen. This review attempts to summarize the most recent advancements in the field of biofilm and antifungal resistance research and offers suggestions for future directions in therapeutics development.
    Matched MeSH terms: Biofilms
  9. Razali, M.H., Ismail, N.A., Osman, U.M., Amin, K.A.M.
    ASM Science Journal, 2018;11(101):158-165.
    MyJurnal
    The aim of this work was to investigate the effect of glycerol concentration on mechanical
    and physical properties of gellan gum (GG) biofilm. The biofilm was prepared using solvent
    casting method and the effective glycerol concentration was found to be within 30-50%
    w/w (based on GG weight). At 60 and 70 w/w% of glycerol, the films started to distort
    because the films was flexible and brittle. As glycerol concentration was increased the tensile
    strength (TS) and Youngs modulus (E) of films decreased. Somehow, elongation at break
    (EAB), water vapor transmission rate (WVTR) and swelling of films was increased. Glycerol
    plasticized GG biofilm was thermally stable and flexible, proposed its can be exploited as
    film-forming material and with optimized glycerol concentration it has good mechanical and
    physical properties for edible biofilm.
    Matched MeSH terms: Biofilms
  10. Gunasegar S, Himratul-Aznita WH
    FEMS Yeast Res., 2019 Mar 01;19(2).
    PMID: 30476044 DOI: 10.1093/femsyr/foy123
    Candida albicans ATCC 14053 and Candida parapsilosis ATCC 22019 hyphal-wall protein 1 (HWP1) are involved in hyphae formation and pathogenesis. The transcriptional agglutinin-like sequence 3 (ALS3) genes in both species are responsible for the development of biofilm and colonization on tooth surfaces. Therefore, we investigated the expression of HWP1 and ALS3 quantitatively in C. albicans and C. parapsilosis and examined the biofilm structure upon exposure to various nicotine concentrations. In vitro, biofilms of Candida species were developed directly on slides using the Lab-Tek Chamber Slide System and visualized by confocal laser scanning microscopy. Quantitative real-time polymerase chain reaction was used to measure HWP1 and ALS3 expression in C. albicans ATCC 14053 and C. parapsilosis ATCC 22019. The results indicated that nicotine multiplied the number of yeast cells and increased the extracellular polysaccharides of Candida species. We also found that 1-2 mg/mL nicotine could enhance the formation of biofilm. The findings also revealed that the expression of HWP1 and ALS3 in Candida species were increased as the nicotine concentration increased. Therefore, nicotine influences the biofilm development of oral-associated C. albicans ATCC 14053 and C. parapsilosis ATCC 22019.
    Matched MeSH terms: Biofilms
  11. Gao Y, Wang X, Li J, Lee CT, Ong PY, Zhang Z, et al.
    Bioresour Technol, 2020 Feb;297:122427.
    PMID: 31784249 DOI: 10.1016/j.biortech.2019.122427
    The novel immobilized microbial granules (IMG) shows a significant effect of nitrification for freshwater aquaculture. However, there is lack of evaluation study on the performance of nitrification at high salinity due to the concentration of recycled water or seawater utilization. A laboratory scale moving bed bioreactor (MBBR) with IMG was tested on recycled synthetic aquaculture wastewater for the nitrification at 2.5 mg/L NH3-N daily. The results indicated that IMG showed a high salinity tolerance and effectively converted ammonia to nitrate up to 92% at high salinity of 35.0 g/L NaCl. As salinity increased from near zero to 35.0 g/L, the microbial activity of nitrite oxidation bacteria (NOB) in the IMG decreased by 86.32%. The microbial community analysis indicated that salinity significantly influenced the community structure. It was found that Nitrosomonas sp. and Nitrospira sp. were the dominant genera for ammonia oxidation bacteria (AOB) and NOB respectively at different salinity levels.
    Matched MeSH terms: Biofilms
  12. Nordin Fatin-Majdina, Haji Abd Rahim Zubaidah, Mohd Bakri Marina, Abd Razak Monica@Munirah
    Sains Malaysiana, 2014;43:1889-1893.
    The effect of S. persica extract on the population of bacteria in single-species biofilm was investigated. An artificial mouth (NAM) system was used for the development of biofilm. In one experiment, aqueous extract of S. persica at sub-MIC concentration (5 mg/mL) was first pumped into the NAM system to treat the experimental pellicle on glass beads before inoculating it with the bacteria (Strep. mitis, Strep. mutans and Strep. sanguinis). This would resemble using the aqueous extract of S. persica before meals. In another experiment, the aqueous extract of S. persica was pumped into the NAM system after the bacterial inoculation and this would resemble using it after meals. In both experiments, 24 h biofilms were allowed to form. The bacterial population of the biofilms was determined and expressed as colony forming unit per mL (cfu mL-1). For negative control, sterilized distilled water was used whereas for positive control, commercial Listerine. It was found that the population of Strep. mitis, Strep. mutans and Strep. sanguinis in the respective biofilms for both experiments involving treatment with S. persica extract or Listerine was significantly reduced by more than 70% (p<0.05) when compared with the negative control. Comparing the effect of S. persica with Listerine on the bacterial population of the biofilms when used either before or after meal showed that S. persica is slightly less effective towards S. sanguinis before meal and towards S. mutans after meal (p<0.05). This study suggests that the efficiency of the antibacterial effect of S. persica is species-related and by its way of usage.
    Matched MeSH terms: Biofilms
  13. Nur Akma Mahat, Norinsan Kamil Othman, Mohd Nazri Idris, Fathul Karim Sahrani
    Sains Malaysiana, 2015;44:1587-1591.
    The efficiency of cetyltrimethylammonium bromide (CTAB) to reduce the activity of consortium bacteria consisting of
    sulphate-reducing bacteria (C-SRB) has been investigated on variable concentration by weight loss test, potentiodynamic
    polarization and diffusion disk methods. C-SRB was isolated from tropical crude oil of Malaysian offshore. Biofilm analysis
    was also evaluated by variable pressure scanning electron microscopy (VPSEM). Weight loss and potentiodynamic
    polarization analyses showed that CTAB is able to inhibit the biocorrosion process and their inhibition efficiency had
    reached to 85 and 65% at 300 ppm CTAB, respectively. Increasing of CTAB efficiency as a function of concentration was
    also supported by diffusion disk analysis. Biofilm analysis showed that less of C-SRB and their metabolic by-product had
    been observed. It was concluded that CTAB was able to reduce the C-SRB activity and prevent biocorrosion process on
    carbon steel surface.
    Matched MeSH terms: Biofilms
  14. Daood U, Parolia A, Elkezza A, Yiu CK, Abbott P, Matinlinna JP, et al.
    Dent Mater, 2019 09;35(9):1264-1278.
    PMID: 31201019 DOI: 10.1016/j.dental.2019.05.020
    OBJECTIVE: To analyze effect of NaOCl+2% quaternary ammonium silane (QAS)-containing novel irrigant against bacteria impregnated inside the root canal system, and to evaluate its antimicrobial and mechanical potential of dentine substrate.

    METHODS: Root canal was prepared using stainless steel K-files™ and ProTaper™ and subjected to manual and ultrasonic irrigation using 6% NaOCl+2% CHX, 6% NaOCl+2% QAS and saline as control. For confocal-microscopy, Raman spectroscopy and SEM analysis before and after treatment, Enterococcus faecalis cultured for 7 days. Raman spectroscopy analysis was done across cut section of gutta percha/sealer-dentine to detect resin infiltration. Indentation of mechanical properties was evaluated using a Berkovich indenter. The contact angle of irrigants and surface free energy were evaluated. Mineralization nodules were detected through Alazarin red after 14 days.

    RESULTS: Control biofilms showed dense green colonies. Majority of E. faecalis bacteria were present in biofilm fluoresced red in NaOCl+2% QAS group. There was reduction of 484cm-1 Raman band and its intensity reached lowest with NaOCl+2% QAS. There was an increase in 1350-1420cm-1 intensity in the NaOCl+2% CHX groups. Gradual decrease in 1639cm-1 and 1609cm-1 Raman signal ratios were seen in the resin-depth region of 17μm>, 14.1μm> and 13.2μm for NaOCl+2% QAS, NaOCl+2% CHX and control groups respectively. All obturated groups showed an intact sealer/dentine interface with a few notable differences. 0.771 and 83.5% creep indentation distance for NaOCl+2% QAS ultrasonic groups were observed. Highest proportion of polar component was significantly found in the NaOCl+2% QAS groups which was significantly higher as compared to other groups. Mineralized nodules were increased in NaOCl+2% QAS.

    SIGNIFICANCE: Favorable antimicrobial and endodontic profile of the NaOCl+2% QAS solution might suggest clinical use for it for more predictable reduction of intracanal bacteria.

    Matched MeSH terms: Biofilms
  15. Waqas S, Bilad MR, Man Z, Wibisono Y, Jaafar J, Indra Mahlia TM, et al.
    J Environ Manage, 2020 Aug 15;268:110718.
    PMID: 32510449 DOI: 10.1016/j.jenvman.2020.110718
    Integrated fixed-film activated sludge (IFAS) process is considered as one of the leading-edge processes that provides a sustainable solution for wastewater treatment. IFAS was introduced as an advancement of the moving bed biofilm reactor by integrating the attached and the suspended growth systems. IFAS offers advantages over the conventional activated sludge process such as reduced footprint, enhanced nutrient removal, complete nitrification, longer solids retention time and better removal of anthropogenic composites. IFAS has been recognized as an attractive option as stated from the results of many pilot and full scales studies. Generally, IFAS achieves >90% removals for combined chemical oxygen demand and ammonia, improves sludge settling properties and enhances operational stability. Recently developed IFAS reactors incorporate frameworks for either methane production, energy generation through algae, or microbial fuel cells. This review details the recent development in IFAS with the focus on the pilot and full-scale applications. The microbial community analyses of IFAS biofilm and floc are underlined along with the special emphasis on organics and nitrogen removals, as well as the future research perspectives.
    Matched MeSH terms: Biofilms
  16. Razali MH, Ismail NA, Amin KAM
    Data Brief, 2020 Jun;30:105478.
    PMID: 32346560 DOI: 10.1016/j.dib.2020.105478
    Gellan gum incorporating titanium dioxide nanoparticles biofilm was synthesized and characterized using UV, FTIR and XRD to study their physical and chemical properties. The mechanical properties were measured using universal mechanical testing. Meanwhile, the biological properties were investigated towards for antibacterial and cell proliferation. This comprehensive data are relevant with the research article entitled "Gellan gum incorporating titanium dioxide nanoparticles biofilm as wound dressing: Physicochemical, mechanical, antibacterial properties and wound healing studies" [1].
    Matched MeSH terms: Biofilms
  17. Yong YK, Wen NCM, Yeo GEC, Chew ZX, Chan LL, Md Zain NZ, et al.
    PMID: 34574752 DOI: 10.3390/ijerph18189828
    Several bacterial species cause post-operative infections, which has been a critical health concern among hospital patients. Our study in this direction is a much-needed exploratory study that was carried out at the National Heart Institute (IJN) of Malaysia to examine the virulence properties of causative bacteria obtained from postoperative patients. The bacterial isolates and data were provided by the IJN. Antibiotic resistance gene patterns, and the ability to form biofilm were investigated for 127 isolates. Klebsiella pneumoniae (36.2%) was the most common isolate collected, which was followed by Pseudomonas aeruginosa (26%), Staphylococcus aureus (23.6%), Streptococcus spp. (8.7%) and Acinetobacter baumannii (5.5%). There were 49 isolates that showed the presence of multidrug resistance genes. The mecA gene was surprisingly found in methicillin-susceptible S. aureus (MSSA), which also carried the ermA gene from those erythromycin-susceptible strains. The phenotypic antibiotic resistance profiles varied greatly between isolates. Findings from the biofilm assay revealed that 44 of the 127 isolates demonstrated the ability to produce biofilms. Our findings provide insights into the possibility of some of these bacteria surviving under antibiotic stress, and some antibiotic resistance genes being silenced.
    Matched MeSH terms: Biofilms
  18. Puah SM, Fong SP, Kee BP, Puthucheary SD, Chua KH
    Microb Pathog, 2022 Jan;162:105345.
    PMID: 34896547 DOI: 10.1016/j.micpath.2021.105345
    Recently, Elizabethkingia species have gained attention as a cause of life-threatening infections. The identification via phenotypic methods of three important species- Elizabethkingia meningoseptica, E. anophelis and E. miricola is difficult. Our objectives were to re-assess 30 archived Flavobacterium meningosepticum isolates using 16S rRNA gene sequencing, ERIC-PCR, and biofilm formation assay. Twenty-four isolates were re-identified as E. anophelis and 6 as E. miricola. All of them had the ability to form biofilm as shown in microtiter plate assay based on crystal violet staining. Overall, E. anophelis had a higher specific biofilm formation index compared to E. miricola. A total of 42% (10 out of 24) of E. anophelis were classified as strong, 29% (7 out of 24) as moderate and 29% (7 out of 24) as weak biofilm producers. E. miricola, 17% (1 out of 6) isolates were strong biofilm producers, 50% (3 out of 6) moderate and 33% (2 out of 6) were weak producers. E. anophelis from tracheal secretions were significantly associated with (p = 0.0361) strong biofilm formation. In summary, this study showed that the isolates originally identified as F. meningosepticum were re-classified using the 16S rRNA gene as one of two Elizabethkingia species. The ability of E. anophelis to form strong biofilm in endotracheal tubes indicates their probable role in the pathogenesis of Elizabethkingia infections.
    Matched MeSH terms: Biofilms
  19. Fouladynezhad, N., Afsah-Hejri, L., Rukayadi, Y., Abdulkarim, S.M., Son, R., Marian, M.N.
    MyJurnal
    Listeria monocytogenes (L. monocytogenes) is a serious food-borne pathogen for immunocompromised individuals. L. monocytogenes is capable of producing biofilm on the surface of food processing lines and instruments. The biofilm transfers contamination to food products and impose risk to public health. Transfers contamination to food products, and impose risk hazard to public health. The aim of this study was to investigate biofilm producing ability of L. monocytogenes isolates. Microtitre assay was used to measure the amount of biofilm production by ten L. monocytogenes isolates from minced chicken / meat, sausages and burgers. Results showed that all 10 L. monocytogenes isolates were able to form biofilm after 24 h at 20˚C on polystyrene surface (the common surface in food industries). Some strains were capable of forming biofilm more than the others. All strains showed a slight raise in the quantities of attached cells over 48 and 72 h. L. monocytogenes strains isolated from minced chicken, minced meat and burgers were better biofilm-producers comparing to the strains isolated from sausages.
    Matched MeSH terms: Biofilms
  20. Nyanasegran PK, Nathan S, Firdaus-Raih M, Muhammad NAN, Ng CL
    J Microbiol Biotechnol, 2023 Jan 28;33(1):15-27.
    PMID: 36451302 DOI: 10.4014/jmb.2207.07032
    The incidence of melioidosis cases caused by the gram-negative pathogen Burkholderia pseudomallei (BP) is seeing an increasing trend that has spread beyond its previously known endemic regions. Biofilms produced by BP have been associated with antimicrobial therapy limitation and relapse melioidosis, thus making it urgently necessary to understand the mechanisms of biofilm formation and their role in BP biology. Microbial cells aggregate and enclose within a self-produced matrix of extracellular polymeric substances (EPSs) to form biofilm. The transition mechanism of bacterial cells from planktonic state to initiate biofilm formation, which involves the formation of surface attachment microcolonies and the maturation of the biofilm matrix, is a dynamic and complex process. Despite the emerging findings on the biofilm formation process, systemic knowledge on the molecular mechanisms of biofilm formation in BP remains fractured. This review provides insights into the signaling systems, matrix composition, and the biosynthesis regulation of EPSs (exopolysaccharide, eDNA and proteins) that facilitate the formation of biofilms in order to present an overview of our current knowledge and the questions that remain regarding BP biofilms.
    Matched MeSH terms: Biofilms
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