Displaying all 11 publications

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  1. Lau TV, Puah SM, Tan JMA, Puthucheary SD, Chua KH
    Braz J Microbiol, 2021 Jun;52(2):517-529.
    PMID: 33768508 DOI: 10.1007/s42770-021-00457-8
    Flagellar-mediated motility is a crucial virulence factor in many bacterial species. A dual flagellar system has been described in aeromonads; however, there is no flagella-related study in the emergent human pathogen Aeromonas dhakensis. Using 46 clinical A. dhakensis, phenotypic motility, genotypic characteristics (flagellar genes and sequence types), biochemical properties and their relationship were investigated in this study. All 46 strains showed swimming motility at 30 °C in 0.3% Bacto agar and carried the most prevalent 6 polar flagellar genes cheA, flgE, flgG, flgH, flgL, and flgN. On the contrary, only 18 strains (39%) demonstrated swarming motility on 0.5% Eiken agar at 30 °C and they harbored 11 lateral flagellar genes lafB, lafK, lafS, lafT, lafU, flgCL, flgGL, flgNL, fliEL, fliFL, and fliGL. No association was found between biochemical properties and motility phenotypes. Interestingly, a significant association between swarming and strains isolated from pus was observed (p = 0.0171). Three strains 187, 277, and 289 isolated from pus belonged to novel sequence types (ST522 and ST524) exhibited fast swimming and swarming profiles, and they harbored > 90% of the flagellar genes tested. Our findings provide a fundamental understanding of flagellar-mediated motility in A. dhakensis.
    Matched MeSH terms: Flagellin/genetics*; Flagellin/metabolism
  2. Bahadoran M, Noorden AF, Mohajer FS, Abd Mubin MH, Chaudhary K, Jalil MA, et al.
    Artif Cells Nanomed Biotechnol, 2016;44(1):315-21.
    PMID: 25133457 DOI: 10.3109/21691401.2014.948549
    A new microring resonator system is proposed for the detection of the Salmonella bacterium in drinking water, which is made up of SiO2-TiO2 waveguide embedded inside thin film layer of the flagellin. The change in refractive index due to the binding of the Salmonella bacterium with flagellin layer causes a shift in the output signal wavelength and the variation in through and drop port's intensities, which leads to the detection of Salmonella bacterium in drinking water. The sensitivity of proposed sensor for detecting of Salmonella bacterium in water solution is 149 nm/RIU and the limit of detection is 7 × 10(-4)RIU.
    Matched MeSH terms: Flagellin/chemistry*
  3. Kong SY, Tran HQ, Gewirtz AT, McKeown-Eyssen G, Fedirko V, Romieu I, et al.
    Cancer Epidemiol Biomarkers Prev, 2016 Feb;25(2):291-301.
    PMID: 26823475 DOI: 10.1158/1055-9965.EPI-15-0798
    BACKGROUND: Chronic inflammation and oxidative stress are thought to be involved in colorectal cancer development. These processes may contribute to leakage of bacterial products, such as lipopolysaccharide (LPS) and flagellin, across the gut barrier. The objective of this study, nested within a prospective cohort, was to examine associations between circulating LPS and flagellin serum antibody levels and colorectal cancer risk.

    METHODS: A total of 1,065 incident colorectal cancer cases (colon, n = 667; rectal, n = 398) were matched (1:1) to control subjects. Serum flagellin- and LPS-specific IgA and IgG levels were quantitated by ELISA. Multivariable conditional logistic regression models were used to calculate ORs and 95% confidence intervals (CI), adjusting for multiple relevant confouding factors.

    RESULTS: Overall, elevated anti-LPS and anti-flagellin biomarker levels were not associated with colorectal cancer risk. After testing potential interactions by various factors relevant for colorectal cancer risk and anti-LPS and anti-flagellin, sex was identified as a statistically significant interaction factor (Pinteraction < 0.05 for all the biomarkers). Analyses stratified by sex showed a statistically significant positive colorectal cancer risk association for men (fully-adjusted OR for highest vs. lowest quartile for total anti-LPS + flagellin, 1.66; 95% CI, 1.10-2.51; Ptrend, 0.049), whereas a borderline statistically significant inverse association was observed for women (fully-adjusted OR, 0.70; 95% CI, 0.47-1.02; Ptrend, 0.18).

    CONCLUSION: In this prospective study on European populations, we found bacterial exposure levels to be positively associated to colorectal cancer risk among men, whereas in women, a possible inverse association may exist.

    IMPACT: Further studies are warranted to better clarify these preliminary observations.

    Matched MeSH terms: Flagellin/blood*
  4. Khoo JJ, Lim FS, Tan KK, Chen FS, Phoon WH, Khor CS, et al.
    J Med Entomol, 2017 09 01;54(5):1444-1448.
    PMID: 28874019 DOI: 10.1093/jme/tjx131
    Spirochetes from the Borrelia genus are known to cause diseases in humans, namely Lyme disease and relapsing fever. These organisms are commonly transmitted to humans by arthropod vectors including ticks, mite, and lice. Here, we report the molecular detection of a Borrelia sp. from a Haemaphysalis hystricis Supino tick collected from wildlife in an Orang Asli settlement in Selangor, Malaysia. Phylogenetic analyses of partial 16s rRNA and flaB gene sequences revealed that the Borrelia sp. is closely related to the relapsing fever group borreliae, Borrelia lonestari, Borrelia miyamotoi, and Borrelia theileri, as well as a number of uncharacterized Borrelia sp. from ticks in Portugal and Japan. To our knowledge, this is the first report of a Borrelia sp. detected in H. hystricis, and in Malaysia. The zoonotic potential of this Borrelia sp. merits further investigation.
    Matched MeSH terms: Flagellin/genetics
  5. Karim A, Yousuf A, Islam MA, Naif YH, Faizal CKM, Alam MZ, et al.
    Biotechnol Prog, 2018 07;34(4):838-845.
    PMID: 29464927 DOI: 10.1002/btpr.2625
    The aim of the study was to investigate the feasibility of using irreversible electroporation (EP) as a microbial cell disruption technique to extract intracellular lipid within short time and in an eco-friendly manner. An EP circuit was designed and fabricated to obtain 4 kV with frequency of 100 Hz of square waves. The yeast cells of Lipomyces starkeyi (L. starkeyi) were treated by EP for 2-10 min where the distance between electrodes was maintained at 2, 4, and 6 cm. Colony forming units (CFU) were counted to observe the cell viability under the high voltage electric field. The forces of the pulsing electric field caused significant damage to the cell wall of L. starkeyi and the disruption of microbial cells was visualized by field emission scanning electron microscopic (FESEM) image. After breaking the cell wall, lipid was extracted and measured to assess the efficiency of EP over other techniques. The extent of cell inactivation was up to 95% when the electrodes were placed at the distance of 2 cm, which provided high treatment intensity (36.7 kWh m-3 ). At this condition, maximum lipid (63 mg g-1 ) was extracted when the biomass was treated for 10 min. During the comparison, EP could extract 31.88% lipid while the amount was 11.89% for ultrasonic and 16.8% for Fenton's reagent. The results recommend that the EP is a promising technique for lowering the time and solvent usage for lipid extraction from microbial biomass. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:838-845, 2018.
    Matched MeSH terms: Flagellin/metabolism
  6. Tay ST, Cheah PC, Puthucheary SD
    J Clin Microbiol, 2010 Apr;48(4):1465-7.
    PMID: 20089759 DOI: 10.1128/JCM.01131-09
    Four flagellin allelic types (I to IV) of Burkholderia pseudomallei were identified based on their sequence variation and restriction fragment length polymorphism (RFLP) analysis of the amplified flagellin gene. Flagellin allelic type I was the most predominantly (75.0%) found among the 100 clinical isolates of B. pseudomallei investigated in this study.
    Matched MeSH terms: Flagellin/genetics*
  7. Winstanley C, Hales BA, Morgan JAW, Gallagher MJ, Puthucheary SD, CISSé MF, et al.
    J Med Microbiol, 1999 Jul;48(7):657-662.
    PMID: 10403416 DOI: 10.1099/00222615-48-7-657
    PCR and restriction fragment length polymorphism (RFLP) typing of flagellin genes (fliC) from 57 clinical isolates of Burkholderia cepacia indicated that only type 11 flagellins were present. Twenty-two isolates previously identified as the epidemic UK cystic fibrosis strain were indistinguishable by this method, as were 11 isolates from a pseudo-outbreak in Senegal. Other clinical isolates, including 19 from disparate sources in Malaysia, were separated into nine fliC RFLP groups, exhibiting a large degree of divergence. When isolates were indistinguishable by fliC genotyping, their similarity was confirmed by whole genome macro-restriction analysis with pulsed-field gel electrophoresis following XbaI digestion. The variation in fliC sequences of B. cepacia was far greater than that with B. pseudomallei, supporting the view that 'B. cepacia', as currently defined, may comprise several different genomic species.
    Matched MeSH terms: Flagellin/genetics*; Flagellin/chemistry
  8. Fedirko V, Tran HQ, Gewirtz AT, Stepien M, Trichopoulou A, Aleksandrova K, et al.
    BMC Med, 2017 04 04;15(1):72.
    PMID: 28372583 DOI: 10.1186/s12916-017-0830-8
    BACKGROUND: Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking.

    METHODS: We used a case-control study design nested within a large prospective cohort to assess the association between circulating levels of anti-lipopolysaccharide (LPS) and anti-flagellin immunoglobulin A (IgA) and G (IgG) (reflecting long-term exposures to LPS and flagellin, respectively) and risk of hepatocellular carcinoma. A total of 139 men and women diagnosed with hepatocellular carcinoma between 1992 and 2010 were matched to 139 control subjects. Multivariable rate ratios (RRs), including adjustment for potential confounders, hepatitis B/C positivity, and degree of liver dysfunction, were calculated with conditional logistic regression.

    RESULTS: Antibody response to LPS and flagellin was associated with a statistically significant increase in the risk of hepatocellular carcinoma (highest vs. lowest quartile: RR = 11.76, 95% confidence interval = 1.70-81.40; P trend = 0.021). This finding did not vary substantially by time from enrollment to diagnosis, and did not change after adjustment for chronic infection with hepatitis B and C viruses.

    CONCLUSIONS: These novel findings, based on exposures up to several years prior to diagnosis, support a role for gut-derived bacterial products in hepatocellular carcinoma development. Further study into the role of gut barrier failure and exposure to bacterial products in liver diseases is warranted.

    Matched MeSH terms: Flagellin/immunology*
  9. Ho WS, Tan LK, Ooi PT, Yeo CC, Thong KL
    BMC Vet Res, 2013;9:109.
    PMID: 23731465 DOI: 10.1186/1746-6148-9-109
    Postweaning diarrhea caused by pathogenic Escherichia coli, in particular verotoxigenic E. coli (VTEC), has caused significant economic losses in the pig farming industry worldwide. However, there is limited information on VTEC in Malaysia. The objective of this study was to characterize pathogenic E. coli isolated from post-weaning piglets and growers with respect to their antibiograms, carriage of extended-spectrum beta-lactamases, pathotypes, production of hemolysins and fimbrial adhesins, serotypes, and genotypes.
    Matched MeSH terms: Flagellin/genetics
  10. Saad SM, Abdullah J, Rashid SA, Fen YW, Salam F, Yih LH
    Mikrochim Acta, 2019 11 19;186(12):804.
    PMID: 31745737 DOI: 10.1007/s00604-019-3913-8
    A fluorometric assay is described for highly sensitive quantification of Escherichia coli O157:H7. Reporter oligos were immobilized on graphene quantum dots (GQDs), and quencher oligos were immobilized on gold nanoparticles (AuNPs). Target DNA was co-hybridized with reporter oligos on the GQDs and quencher oligos on AuNPs. This triggers quenching of fluorescence (with excitation/emission peaks at 400 nm/530 nm). On introducing target into the system, fluorescence is quenched by up to 95% by 100 nM concentrations of target oligos having 20 bp. The response to the fliC gene of E. coli O157:H7 increases with the logarithm of the concentration in the range from 0.1 nM to 150 nM. The limit of detection is 1.1 ± 0.6 nM for n = 3. The selectivity and specificity of the assay was confirmed by evaluating the various oligos sequences and PCR product (fliC gene) amplified from genomic DNA of the food samples spiked with E. coli O157:H7. Graphical abstractSchematic representation of fluorometric assay for highly sensitive quantification of Escherichia coli O157:H7 based on fluorescence quenching gene assay for fliC gene of E. coli O157:H7.
    Matched MeSH terms: Flagellin/genetics
  11. Suria, M. S., Adlin Azlina, A. K., Mohd Afendy, A. T., Zamri, I.
    MyJurnal
    Shiga toxin-producing E. coli (STEC) is an important foodborne pathogen causing diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome in humans. STEC is an implicated in the vast majority of outbreaks, widely via consumption of STEC contaminated beef, as important vehicle of transmission of this organism to human. The E. coli O157:H7 serotype is traditionally identified by serological identification of the somatic antigen (O157) and structural flagella (H7). In this study, the bacteria were identified as STEC serotype O157:H7 with three primer pairs that amplified fragments of secD, rfbE and fliC genes in PCR assays. These primer pairs specifically amplified different sizes of target genes: a 244bp region of the E. coli diagnostic marker gene (secD); a 317bp region of the O157 lipopolysacharide (LPS) gene (rfbE); and a 381bp region of the H7 flagellin gene (fliC). The singleplex, duplex and triplex PCR assay developed in this study have a sensitivity limit at 2.8 x 103, 2.8 x 105 and 2.8 x 107 CFU/ml of E. coli O157:H7, respectively. Sensitivity to detect trace amount of E. coli O157:H7 DNA was reduced as the number of primer used was increased for competing to the same DNA template.
    Matched MeSH terms: Flagellin
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